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Entries22216337
Edits20002
Editor100
Entries22216337
Edits20002
EditorCalcium powder, commonly known as limestone and stone powder , is mainly composed of calcium carbonate , which is weakly alkaline , difficult to dissolve in water, and soluble in acid. Calcium powder distribution It is a common substance on the earth and is found in rocks such as aragonite , calcite , chalk, limestone, marble, and travertine. It is also the main component of animal bones or shells. Calcium powder classification Calcium powder can be divided into: heavy calcium powder, light calcium powder , active calcium powder , flue gas desulfurization calcium powder, ultrafine calcium carbonate , etc. Heavy calcium powder The shape of heavy calcium carbonate is irregular, its particle size varies greatly, and the particles have certain edges and corners, the surface is rough, the particle size distribution is wide, the particle size is large, and the average particle size is generally 1~10 μm . Heavy calcium carbonate is divided into: coarsely ground calcium carbonate (above 3μm), finely ground calcium carbonate (1~3μm), and ultrafine calcium carbonate (0.5~1μm) according to its original average particle size (d). The powder characteristics of heavy calcium carbonate are: (1) irregular particle shape ; (2) wide particle size distribution; (3) large particle size. Calcium carbonate has been widely used in papermaking , plastics, plastic films , chemical fibers , rubber , adhesives, sealants , daily chemicals, cosmetics, building materials, coatings, paints, inks, putties, sealing wax , putty , felt packaging, medicine, and food. (such as chewing gum , chocolate ) and feed, its functions are: increasing product volume, reducing costs , improving processing properties (such as adjusting viscosity, rheological properties, vulcanization properties), improving dimensional stability , reinforcing or semi-reinforcing, improving Printing performance, improve physical properties (such as heat resistance , matting, abrasion resistance , flame retardancy , whiteness, gloss ), etc. Light calcium powder Widely used in papermaking, plastics, plastic films, chemical fibers, rubber, adhesives, sealants, daily chemicals, cosmetics, building materials, coatings, paints, inks, putties, sealing wax, putty, felt packaging, medicine, food (such as chewing gum) , chocolate) and feed, its functions include: increasing product volume, reducing costs, improving processing properties (such as adjusting viscosity, rheological properties, vulcanization properties), improving dimensional stability, reinforcing or semi-reinforcing, improving printing performance, Improve physical properties (such as heat resistance, matting, abrasion resistance, flame retardancy, whiteness, gloss), etc. Active calcium powder Calcium supplements. It can promote the calcification of bone marrow and teeth, maintain the normal excitability of nerves and muscles , and reduce capillary permeability. Used to prevent and treat chronic diseases caused by calcium deficiency. The main purpose 1. Calcium powder for rubber industry Rubber – Calcium powder for rubber: 400 mesh, whiteness: 93%, calcium content: 96%, calcium powder is one of the largest fillers used in the rubber industry . Calcium powder is filled in large amounts in rubber, which can increase the volume of its products and save expensive natural rubber , thus greatly reducing costs. Calcium powder is filled into rubber to obtain higher tensile strength , tear strength and wear resistance than pure rubber vulcanization . 2. Value of calcium powder used in plastics industry Calcium powder 400 mesh is used for plastic masterbatch and color masterbatch . It is required that the whiteness remains unchanged after high temperature heating. The ore structure is large crystalline calcite. Calcium powder content: 99%, whiteness: 95%. Calcium powder can play a role in plastic products. It is a kind of skeleton that plays a great role in the dimensional stability of plastic products. It can also increase the hardness of the products and improve the surface gloss and surface smoothness of the products. Since the whiteness of calcium carbonate is above 90, it can also replace expensive white pigments. 3. Calcium powder for paint industry Calcium powder for paints and latex paints is 800 mesh or 1000 mesh, whiteness: 95%, calcium carbonate: 96%. The amount of calcium powder used in the paint industry is also large, for example, the amount used in thick paint is more than 30%. 4. Calcium powder for water-based coating industry Calcium powder for water-based coatings is 800 mesh or 1000 mesh, whiteness: 95%, calcium powder: 96%. Calcium powder is more widely used in the water-based coating industry. It can make the coating non-settling, easy to disperse, good gloss and other characteristics. The dosage of water-based paint is 20-60%. 5. Calcium powder for papermaking industry Heavy calcium powder for papermaking 325 mesh, whiteness requirement: 95%, calcium powder content: 98%, calcium powder plays an important role in the papermaking industry , it can ensure the strength and whiteness of the paper, and the cost is low. 6. Dry mortar , concrete and calcium powder for construction industry The dry mortar uses calcium powder 325 mesh, whiteness requirement: 95%, calcium powder content: 98%, calcium powder plays an important role in concrete in the construction industry. Not only can it reduce production costs , but it can also increase the toughness and strength of the product. 7. Calcium powder for fireproof ceiling industry Calcium powder for fireproof ceilings is 600 mesh, whiteness requirement: 95%, calcium powder content: 98.5%. Calcium powder is needed in the production process of fireproof ceilings . It can improve the whiteness and brightness of the product, and the fireproof performance will also be increased. 8. Calcium powder for artificial marble industry Calcium powder for artificial marble is 325 mesh, whiteness requirement: 95%, calcium powder content: 98.5%, pure and without impurities, calcium carbonate has been widely used in artificial marble production. 9. Calcium powder for floor tile industry Calcium powder for floor tiles is 400 mesh, whiteness requirement: 95%, calcium powder content: 98.5%, pure and free of impurities. Calcium powder can be used in the floor tile industry to increase the whiteness and tensile strength of the product, improve the toughness of the product, and reduce production costs.
C-reactive protein (CRP) is a protein (acute protein) that rises sharply in the plasma when the body is infected or tissue damaged. It activates complement and strengthens the phagocytosis of phagocytes to play a regulatory role in clearing the invading body. Pathogenic microorganisms and damaged, necrotic, and apoptotic tissue cells. definition C-reactive protein (CRP) refers to some proteins (acute proteins) that rise sharply in the plasma when the body is infected or tissue damaged. CRP can activate complement and strengthen phagocytosis by phagocytes to play a regulatory role, thereby eliminating pathogenic microorganisms that invade the body and damaged, necrotic, and apoptotic tissue cells , and plays an important protective role in the body’s natural immune process. characteristic CRP is not only a non-specific inflammatory marker, but also directly involved incardiovascular diseases such as inflammation and atherosclerosis , and is the most powerful predictor and risk factor for cardiovascular diseases. The interaction between CRP and complement C1q and FcTR enables it to exhibit many biological activities, including host defense response to infection, phagocytosis and regulation of inflammatory response, etc. The combination with damaged cells, apoptotic cells and nuclear antigens also plays an important role in autoimmune diseases. normal value Which detection method is used depends on the conditions of each laboratory and the requirements for sensitivity and specificity. Immunodiffusion, radioimmunoassay, turbidimetry, and enzyme-labeled immunoassay methods all have practical value. Normal value: 800-8000μg/L (immunodiffusion or turbidity method) . Nursing precautions 1. Do not eat greasy or high-protein foods the day before blood drawing , and avoid drinking a lot of alcohol. The ethanol content in the blood will directly affect the test results. 2. After 20:00 on the day before blood collection, you should fast for 12 hours to avoid affecting the test results. 3. When collecting urine specimens for examination, clean the vulva before collecting urine. The container used should be clean and free of contamination. Chemical substances such as detergents, disinfectants, and preservatives should not be mixed to avoid affecting the examination results. 4. Women should prevent leucorrhea from being mixed into urine. Pay attention to expelling part of the urine first, and then collect the specimen, that is, collect the mid-section urine. 5. Urine should be sent for testing immediately after retention to avoid erroneous test results caused by urine retention. Related diseases Malignant myxoma of the left atrium , mucocutaneous lymphaden syndrome, Takayasu arteritis, microscopic polyangiitis , nonspecific systemic necrotizing small vessel vasculitis , pediatric Historian-Johanne syndrome , pediatric Takayasu arteritis , adult still’s disease, rheumatic fever, pediatric pneumonia clinical significance Clinical significance of CRP measurement: (1) The levels of acute inflammation, tissue damage, myocardial infarction , surgical trauma, radiation damage and other diseases increase rapidly within hours after the onset, and tend to increase exponentially. When the disease improves, it quickly drops to normal, and its increase is positively correlated with the degree of infection. The patient’s CRP increases after surgery, and the CRP level should decrease 7 to 10 days after surgery. If CRP does not decrease or increases again, it indicates possible complications such as infection or thromboembolism. (2) CRP is closely related to other inflammatory factors, such as the total number of white blood cells, erythrocyte sedimentation rate, and polymorphonuclear leukocytes. There is a positive correlation with WBC. Plays an active role in the inflammatory response and gives the body non-specific resistance. When a patient’s disease attacks, it can rise earlier than WBC and return to normal quickly, so it has extremely high sensitivity. (3) Help identify types of respiratory infections. CRP can be used for the differential diagnosis of bacterial and viral infections: During bacterial infection, CRP levels increase; while during viral infections, CRP does not increase or is slightly increased. Therefore, the CRP value can help doctors identify the type of respiratory tract infection and be targeted. of medication and treatment. (4) CRP is elevated in patients with malignant tumors . For example, the joint detection of CRP and AFP can be used for the differential diagnosis of liver cancer and benign liver diseases, and can be used to judge the efficacy and prognosis of liver cancer. CRP increases before surgery and decreases after surgery, and its response is not affected by radiotherapy, chemotherapy, and corticosteroid treatment, which is helpful to evaluate the progression of the tumor. (5) Assess the severity of acute pancreatitis . When CRP is higher than 250 mg/L, it indicates extensive necrotizing pancreatitis. (6) Using the ultra-sensitive latex enhanced method to measure CRP can improve the sensitivity of the measurement and can be used to predict the risk of coronary heart disease and myocardial infarction .
Baking powder is a compound additive mainly used in the production of flour products and puffed foods. Baking powder contains a variety of substances, the main components of which are sodium bicarbonate and tartaric acid. Usually a compound of carbonate and solid acid. When carbonates come into contact with water and acids, they break down into a variety of substances. During this process, a high is released, but no flavor is produced. Therefore, the taste of the product is inconvenient. Fermentation There are generally three fermentation methods for making fermented dough: old yeast, fresh yeast, and baking powder. Fresh yeast and baking powder are commonly used in households. Pay careful attention to the aluminum content in baking powder. Aluminum content in food exceeding national standards can cause harm to the human body. Yeast and baking powder both have the function of fermentation, but they are essentially different. Yeast is a pure biological leavening agent, an active microorganism, which will not cause any harm to the human body; while chemical baking powder is a chemical leavening agent, generally referring to baking soda (sodium bicarbonate), stink powder (ammonium bicarbonate), alum ( Potassium aluminum sulfate or potassium aluminum sulfate, SAS), baking powder (baking powder) and other substances. Classification chemical leavening agent baking powder 1. Baking soda ( sodium bicarbonate ,): Under the action of acidic substances contained in food , baking soda can be decomposed into sodium ions , water and carbon dioxide gas, the latter of which can fluff food. However, the reaction of baking soda to release gas requires the presence of acidic substances and is completed in a very short time. The initiation of the reaction is difficult to control. If the dosage is too large, it will produce a bitter or astringent taste . For these reasons, baking soda is rarely used as a leavening agent alone, and is generally used as one of the components of a compound leavening agent. 2. Stinky powder ( ammonium bicarbonate ): Stinky powder is generally used when a large amount of gas needs to be generated quickly. Stinky powder will decompose into water, ammonia and carbon dioxide gas when heated or under acidic conditions . Due to the rapid release, very little ammonia gas remains in the finished product, and there will be no ammonia smell in the finished product. Since stink powder easily decomposes and releases ammonia gas (this is where the name of stink powder comes from) and loses its effect, it is difficult to store and is generally rarely used in households. Stinky powder is used when baking peach cakes or certain biscuits. 3. Alum (potassium aluminum sulfate or potassium aluminum sulfate, SAS): Commonly used alum is actually an acidic mixture, which releases gas when it interacts with food’s inherent or added ingredients such as baking soda, which has a fluffy effect. It is generally also an acid component used as a compound fluffing agent. The characteristic is that it can react quickly at high temperatures . A common example is for frying fried dough sticks baking powde 1. Baking powder: It is a compound leavening agent, and there are many different types. Generally, solid alkali and acid powders are mixed . They do not contact or react under dry conditions. Once they come into contact with water, they will dissolve and contact, and the reaction will release gas. Solid alkali powder is commonly used in baking soda, and solid acid powder includes tartar ( tartar) and phosphate (phosphate, such as calcium phosphate and sodium pyrophosphate ). Their reaction speeds are very fast; in addition, alum (SAS) is used. ) as a solid acid, the reaction rate is much slower, but very fast at high temperatures. Alum is commonly found in Double-acting (DA) baking powders. Double effect means that after mixing water and flour, baking soda first reacts with a fast solid acid (such as cream of tartar) to release the first batch of gas. At this time, alum and baking soda basically do not react, but when heated, alum When heated with baking soda, a second batch of gas is released, which is called double-acting. Commonly seen on the market is double active baking powder. Some self-raising flours also have baking powder already mixed into them and need to be baked quickly after adding water. Because baking powder is easy to store and easy to control, it has become the most commonly used leavening agent and is used in most Western-style pastries. 2. Dangers of chemical leavening agents : Since the reaction products of baking soda and stink powder ( carbon dioxide , ammonia) are also products of human metabolism, as long as they are not used excessively, they will not cause obvious health problems , but they will destroy certain nutrients in food such as vitamins. And both alum and baking powder contain aluminum. Many international reports have pointed out that aluminum is closely related to Alzheimer’s disease . It also reduces memory, suppresses immune function , and hinders nerve conduction . Moreover, aluminum is excreted very slowly from the human body. The amount of alum and baking powder in food should be strictly controlled. Use and try to eat less aluminum-containing foods. biological leavening agent Yeast is a unicellular facultative anaerobic eukaryotic microorganism. After being added to the dough, it can produce carbon dioxide gas through its own metabolism to achieve the purpose of fluffiness. This process is often called fermentation. In the past, old noodles were often fermented, mainly relying on wild yeast and some miscellaneous bacteria. Dough usually contains organic acids, which give it a sour taste. Baking soda needs to be added to neutralize the sour taste. Bacterial metabolites and added baking soda may introduce harmful ingredients or destroy nutrients. The active yeast commonly used in modern times has high purity and rarely produces acidic substances. At the same time, yeast itself is composed of protein and carbohydrates, and is rich in B vitamins and other trace elements such as calcium and iron, and is rich in nutrients. value. Yeast acts as a leavening agent for pasta and requires sufficient time and temperature to produce carbon dioxide. Obviously, yeast is a beneficial biological leavening agent that has no negative impact on the human body and can provide nutrients and vitamins that humans need but lack. is the most ideal fermentation method. It is essentially different from chemical baking powder. Simply put, yeast is not chemical baking powder!
Dyes refer to a class of organic compounds that can give other substances a bright and firm color. Since the pigments used today are all artificially synthesized, they are also called synthetic dyes. Dyes and pigments are generally compounds that have their own color and can make other substances obtain bright and firm colors in a molecular or dispersed state. Dye classification According to dye properties and application methods, dyes can be classified as follows. According to status Water-based color paste, oil-based color paste, water-based color, essential oil-based color essence According to use Ceramic Pigments Coating Pigments Textile Pigments Plastic Pigments According to source Natural dyes are divided into plant dyes, animal dyes, and synthetic dyes (also known as artificial dyes ) according to their usage. According to dye properties and application methods Direct dyes , insoluble azo dyes , reactive dyes, vat dyes, soluble vat dyes, sulfur dyes, sulfur vat dyes , phthalocyanine dyes, oxidation dyes, condensation dyes, disperse dyes, acid dyes, acidic mordants and acidic mordant dyes, basic and cationic dyes. direct dyes This type of dye gets its name because it can be dyed directly on various fibers such as cotton, linen, silk, and wool without relying on other chemicals. Its dyeing method is simple, the chromatogram is complete, and the cost is low. However, its washing and light fastness are poor. If appropriate treatment methods are used, the fastness of the dyed finished product can be improved. reactive dyes Also known as reactive dyes. This type of dye is a new type of dye that was only developed in the 1950s. Its molecular structure contains one or more active groups, which can chemically react with fibers under appropriate conditions to form covalent bonds. It can be used for dyeing cotton, linen, silk, wool, viscose, nylon, vinylon and other textiles. Sulfur dyes Most of these dyes are insoluble in water and organic solvents , but can be dissolved in alkali sulfide solution. After dissolution, they can be directly dyed on fibers. However, because the dye solution is too alkaline, it is not suitable for dyeing protein fibers. This type of dye has a uniform chromatogram, is cheap, and has good color fastness, but the color is not bright. Disperse dyes This type of dye has very low solubility in water, very fine particles, and is a dispersion in the dye liquor. It is a non-ionic dye and is mainly used for dyeing polyester with high dye fastness. Acid Dyestuff This type of dye is water-soluble, and most of them contain sulfonic acid groups, carboxyl groups and other water-soluble genes. Protein fibers can be dyed directly in acidic, weakly acidic or neutral media, but the wet processing fastness is poor. coating It is suitable for all fibers. Through the mechanical attachment of resin to fibers, dark fabrics will become hard, but the color registration is very accurate. Most of them have good light fastness and good washing fastness, especially medium and light. Dye naming The various types of dyes introduced above are not only numerous in number, but also have different properties and usage methods for each type of dye. In order to facilitate distinction and mastery, a unified naming method for dyes has been officially adopted. As long as you see the name of the dye, you can roughly know what type of dye it belongs to, as well as its color, luster, etc. Our country uniformly uses a three-section nomenclature for the naming of dyes. The name of the dye is divided into three parts, namely, the title, the color name and the endnote. 1. The title mainly indicates the name of the dye according to its application method or properties, such as disperse, reduction, reactive, direct, etc. 2. The color name indicates the name of the color that can be obtained by dyeing fabrics with this dye according to standard methods. Generally, there are four ways to express it: (1) Use common physical names, such as red, green, blue, etc. (2) Use plant names, such as orange, peach , grass green, rose, etc. (3) Use natural phenomena to express it, such as sky blue, golden color, etc. (4) Expressed by animal names, such as rat gray, goose yellow, etc. 3. The endnote indicates the shade, performance, status, concentration of the dye and the fabrics it is suitable for, etc. It is generally represented by letters and numbers. The three-section nomenclature of dyes is more convenient to use. For example, vat violet RR, you can know that this is a purple vat dye with red light. The title is reduction, the color name is purple, R means red light, and the two R means the red light is heavier. At present, the naming of dyes has not been unified in all countries in the world. Each dyeing factory has a name for each dye it produces. Therefore, the same dye may have several names. Dye application 1. Select dyes based on fiber properties. Due to the different properties of various fibers, it is necessary to select suitable dyes when dyeing. For example , when dyeing cotton fiber , because its molecular structure contains many hydrophilic hydroxyl groups, it is easy to absorb moisture and swell, can react chemically with reactive groups, and is more resistant to alkali, so you can choose direct, reduction, sulfurization, and ice dyes. and reactive dyes. Polyester has strong hydrophobicity and is not resistant to alkali at high temperatures. Generally, the above dyes should not be used, but disperse dyes should be used for dyeing. 2. Select dyes according to the use of the dyed objects. Since the uses of the dyed objects are different, the requirements for the fastness of the dyed finished products are also different. For example, cloth used as curtains is not washed frequently, but it is often exposed to sunlight. Therefore, when dyeing, you should choose dyes with higher light fastness. For dyeing underwear and light-colored fabrics worn in summer, dyes with higher washability, lightfastness, and sweat resistance should be selected because they need to be washed and sun-dried frequently. 3. Select dyes based on dye costs. When selecting dyes, you must not only consider the color and fastness, but also consider the cost and supply of the dyes and additives used . For higher-priced dyes, you should try to replace them with other dyes that can produce the same effect to reduce production costs. 4. Selection of dyes when color matching When color matching is required, attention should be paid to their composition, solubility, color fastness, dye uptake rate and other properties when selecting dyes. Since the dyeing properties of various dyes are different, the dyeing effect is often affected by differences in temperature, solubility, dye uptake, etc. during dyeing. Therefore, when color matching, dyes with similar properties must be selected, and the closer the better, which can be beneficial to the control of process conditions and the stability of dyeing quality. 5. Select dyes based on the properties of dyeing machinery. Due to different dyeing machinery, the properties and requirements for dyes are also different. If it is used for jig dyeing, dyes with higher directness should be selected; for pad dyeing , dyes with lower directness should be selected. Otherwise, products that do not meet the requirements will be dark at the front and light at the back, with uneven color and luster. Environmentally friendly dyes In accordance with the requirements of ecological textiles and the ban on 118 kinds of dyes, environmentally friendly dyes have become the focus of the development of the dye industry and the printing and dyeing industry. Environmentally friendly dyes are an extremely important condition for ensuring the ecology of textiles. In addition to the necessary dyeing performance, applicability of the process, application performance and fastness performance, environmentally friendly dyes also need to meet environmental quality requirements. Environmentally friendly dyes should include the following ten aspects: (1) It does not contain azo dyes that are expressly stipulated by the German government, the European Community and Eco-Tex Standard 100 and will crack and release 22 carcinogenic aromatic amines under specific conditions, regardless of whether these carcinogenic aromatic amines are free in the dye or are produced by the dye. Produced by lysis; (2) Not an allergic dye; (3) Not a carcinogenic dye; (4) It is not an acutely toxic dye; (5) The content of extractable heavy metals is below the limit value; (6) Does not contain environmental hormones; (7) Does not contain chemical substances that can cause environmental pollution; (8) Does not contain variable compounds and persistent organic pollutants; (9) Formaldehyde content is below the specified limit; (10) Varieties that do not contain restricted pesticides and the total amount is below the prescribed limit; Strictly speaking, dyes that can meet the above requirements should be called environmentally friendly dyes. In addition to meeting the above requirements, truly environmentally friendly dyes should also be environmentally friendly during the production process and not produce “three wastes”, even if a small amount of waste is produced. The “three wastes” can also be treated through conventional methods to meet national and local environmental protection and ecological requirements. direct dyes Direct dyes account for the majority of banned dyes. Therefore, in recent years, the development of environmentally friendly direct dyes has become the focus of the development of new varieties in the dye industry. Specific direct dye varieties include the following: (1) Diaminostilbene disulfonic acid direct dyes: These dyes have bright colors and moderate fastness. Direct lightfast orange GGL (CI Direct Orange 39) is an environmentally friendly dye with good performance. Direct Lightfast Yellow 3BLL (CI Direct Yellow 106) is a triazole direct dye with a sunfastness of level 6~7. Direct light fast green IRC (CI direct green 34) has a high dye uptake rate and excellent dye fastness, with sun fastness reaching level 6~7 and washing fastness reaching level 3~4. (2) 4.4`-diaminodiphenylurea direct dyes: These dyes are non-carcinogenic and have high light fastness. There are many application varieties and it is an environmentally friendly dye. Such as direct light fast yellow RSC (CI direct yellow 50), direct light fast red F3B (CI direct red 80), CI direct brown 112, CI direct brown 126, CI direct brown 152, etc. (3) 4.4`-Diaminobenzoylanilide direct dyes: These dyes have good fastness and are environmentally friendly dyes. Such as direct green NB (CI direct green 89), direct yellow-brown N-D3G (CI direct brown 223), direct black N-BN (CI direct black 166), etc. (4) 4.4`-Diaminobenzenesulfonanilide direct dyes: This type of dye is a black direct dye synthesized from diamino compounds, and its dyeing performance and fastness are very good. It is widely used for dyeing cotton, linen, viscose fiber, silk and leather. Products that can replace banned direct dyes have been developed and screened, such as CI Direct Black 166 (Direct Black N-BN), CI Acid Black 210 (Acid Black NT), CI Acid Black 234, etc. (5) Diaminoheterocyclic direct dyes: These dyes are direct dyes synthesized from diaminoheterocyclic compounds , such as dibenzodioxazine direct dyes. These dyes have bright colors, high tinting strength and fastness. , the sun fastness reaches level 7. Representative varieties include CI Direct Blue 106 (Direct Lightfast Brilliant Blue FF2GL), CI Direct Blue 108 (Direct Lightfast Blue FFRL), etc. (6) Environmentally friendly direct dyes for polyester/cotton (polyester/viscose) fabrics: Polyester/cotton, polyester/viscose blended fabrics and other fibers with different properties are dyed in the same bath. This requires direct dyes to have excellent high temperature stability and good It has good lifting power and reproducibility, good fastness and environmental protection performance. The direct blended D-type dye developed by Shanghai Dyestuff Company is an environmentally friendly dye that can achieve the above performance. Currently, there are more than 25 varieties, such as CI Direct Yellow 86 (Direct blended yellow DR), CI Direct Yellow 106 (Direct blended yellow D -3RLL), CI224 direct blended red D-GLN, CI direct purple 66 (direct blended purple D-5BL), CI direct blue 70 (direct blended blue D-RGL), CI95 direct blended brown D-RS, CI direct black 166 (Directly blended black D-ANBA) etc. Some of the varieties are copper complexes, and free copper should be within the limit value (250mg/kg) specified by ETAD. (7) Kayaelon C-type dyes developed and screened by Nippon Chemical Company: CI Direct Yellow 161 (Yellow C-3RL), CI Direct Red 83 (Rubine C-BL), CI Direct Blue 288 (Blue C-BK), CI direct green 59 (Caeen C-CK), CI direct black 117 (Crey C-RL), etc. Thailand’s Modern Group has launched the Modern Direct series of advanced direct dyes, Dystar has developed the Sirius Plus series of direct dyes, Ciba has launched Cibafix ECO direct dyes, BASF has launched the Diazol series of direct dyes, Yorkshire has launched the Benganil series of direct dyes, etc. These dyes have similar functions, such as bright colors, high light fastness, environmentally friendly dyes that do not contain heavy metals, excellent high temperature stability, and are suitable for one-bath and one-step dyeing of polyester-cotton blended fabrics. Acid Dyestuff (1) Red, orange and yellow acid dyes. Among the acidic environmentally friendly dyes that have been developed, red acid dyes include: CI acid red 37, CI acid red 89 (weak acid red 3B, 2BS), CI acid red 145 (weak acid red GL )wait. CI Acid Red 336 and CI Acid Red 361 are both important varieties of the red spectrum. Orange acid dyes include: CI acid orange 67 (weak acid yellow RXL), CI acid orange 116 (acid orange AGT), CI acid orange 156 (weak acid orange 3G). The main yellow acid dyes are: CI acid yellow 42 (weak acid yellow Rs, acid yellow R) and CI acid yellow 49 (acid yellow GR200). (2) Blue, green, and purple acid dyes. Most of the environmentally friendly acid dyes in the blue spectrum are bromine derivatives, and there are many new blue varieties, such as CI acid blue 277, CI acid blue 344, CI acid blue 350, CI acid Blue 9 (Brilliant Blue FCF) etc. Green acid dyes are of the anthraquinone type. New products that have been developed in China include CI Green 17, CI Acid Green 28, CI Acid Green 41, CI Acid Green 81, etc. The purple ones mainly include CI acid violet 17 (acid violet 4BNS), CI acid violet 54 (weakly acidic brilliant red 10B), CI acid violet 48, etc. (3) Brown and black acid dyes There are also many new varieties of brown acid dyes, the more important ones are CI acid brown 75, CI acid brown 98, CI acid brown 165, CI acid brown 348, CI acid brown 349, etc. The main black varieties include CI Acid Black 26, CI Acid Black 63, CI Acid Black 172, CI Acid Black 194, CI Acid Black 210, CI Acid Black 234, CI Acid Black 235, CI Acid Black 242, etc. Disperse dyes Disperse dyes have more than 1,200 molecular structures so far, and the number of products has reached more than 3,500. Disperse dyes have some incompatibility with the environment and ecological protection. The main reason is that some disperse dyes will reduce and decompose to produce carcinogenic aromatic amines. Some products are allergic dyes. Many products have AOX problems and due to the heat in the printing and dyeing process. Reduced fastness caused by migration , etc. In recent years, in order to improve the functions and environmental protection requirements of disperse dyes, some new dyes have been developed, mainly in the following aspects: (1) New disperse dyes that meet the requirements of Eco-Tex Standard 100. Such products mainly include Ciba Refining Company’s Cibacet EL series of dyes used for dyeing acetate fiber and its blended fabrics; BASF Company’s Dispersol C-VS for polyester A series of dyes for dyeing fibers and blended fabrics; Yorkshire Company’s Serisol ECF environmentally friendly disperse dyes for acetate fiber dyeing; Mitsui-BASF Company’s Compact ECO series dyes; Nippon Chemical Company’s Kayalon Polyester LW is suitable for polyester fibers and polyurethane A series of disperse dyes for dyeing blended fabrics composed of fibers ; Japan’s Sumitomo Company’s Sumikaron MF dye is suitable for dyeing fine-denier polyester fibers. (2) New disperse dyes that replace allergic disperse dyes. CI Disperse Orange 76 and CI Disperse Orange 37 are the most commonly used allergic disperse dyes recognized on the market. The main ones used to replace allergenic dyes are Kayalon Polyester Yellow Brown 3RL (EC) 143 from Nippon Chemical Company; Dianix Orange UN-SE 01 environmentally friendly disperse dye developed by DyStar Company; Sumikaron Blac S-EC 300 from Sumitomo Chemical Company of Japan % disperse dyes; Lumacron Black FD disperse dyes developed by the British company LJSpecialities, etc. (3) New disperse dyes that do not contain adsorbable organic halides. This type of dye mainly includes Terasil Blue W-BLS dye from Ciba Refining Company, which is suitable for exhaust dyeing and continuous dyeing of polyester fiber and its blended fabrics; Palanil Cyanine B 200% and Palanil Luminous Yellow GN developed by BASF are also ultra-bright disperse dyes that do not contain adsorbable organic halides. They are suitable for dyeing polyester fibers and their blended fabrics; the company has also launched Dispersol to the market Deep Red SF is a new generation of high-performance disperse dyes. (4) High-performance disperse dyes with excellent washing fastness. Such products mainly include the Terasil W series new disperse dyes with excellent wet fastness developed by Ciba Refining Company, which has 11 varieties; Dianix HF dyes developed by DyStar Company It is also a high-performance disperse dye with very good washing fastness, excellent application performance, ease of use and other characteristics; BASF’s Dispersol XF is a new disperse dye with top-level washing fastness; and Clariant’s Foron Blue RD -SE 300, which is a high-strength black disperse dye for rapid dyeing, has high lifting power and dye bath adsorption rate, especially the dyed product has good wet fastness after heat fixation; developed by the British company LJSpecialities A new type of disperse dye with excellent washing fastness, the trade name is Itosperse HW dye, which has excellent washing and sublimation fastness and is harmless to the ecological environment. (5) Environmentally friendly disperse dyes composed of biodegradable dispersants. Dispersants in disperse dye products are also a factor that affects environmental protection. The naphthalene sulfonate formaldehyde condensate series dispersants and lignin sulfonate series dispersants have been widely used so far. Agents, etc. are all a matter of biodegradability. In recent years, BASF has successfully developed a new biodegradable dispersant Setamol E. DyStar has also developed new biodegradable dispersants and used them to form environmentally friendly disperse dyes such as Dianix ECO Liquid series dyes. reactive dyes (1) Environmentally friendly reactive dyes with high fixation rates. Currently, domestic reactive dyes with higher fixation rates include KE type, ME type, and B type. Foreign reactive dyes include Procion H-EXL, Sumifix Supra, Basilen Fm, and Cibacron. Type C. The fixation rate of these new reactive dyes is above 80%. They have good level dyeing and diffusibility and are not affected by changes in liquor ratio, temperature, and salt content. They are also good in washability because they have a suitable one-time exhaustion rate. , has excellent light fastness and perspiration fastness. (2) Environmentally friendly reactive dyes for low-salt dyeing. In the process of reactive dye dyeing, inorganic salts are commonly used as dye accelerators and are added to the dye liquor. High-salt wastewater destroys the ecological environment of the water and is harmful to crops and humans. serious threat. Sumitomo Corporation of Japan uses environmentally friendly series of dyes such as Sumifix Supra NF and E-XF. The salt dosage is 60% of ordinary dyes; Ciba Corporation’s Cibacron LS dye has a particularly high affinity for fibers, good dye solubility, and high bond fastness. , the salt consumption is low, only 1/3~1/2 of general reactive dyes, the dye uptake rate is over 90%, and the color fixation rate is 80%; Kayacion E-CM dyes and Kayacion E-MS developed by Nippon Chemical Company Dyes, Kayacion E-S133 dyes, and DyStar’s Levafix EA, Levafix ES, and Levafix OS series dyes all have the function of low-salt dyeing. The dyes have good solubility, good level dyeing, and low salt consumption, which is environmentally friendly. new products. (3) Environmentally friendly reactive dyes that do not contain heavy metals and adsorbable organic halides. These reactive dyes mainly include Ciba-cron Black CNN, Black W-NN, Black C-2R, Black LS-N, etc. and domestic reactive dyes. Black KN-GZGC133 (granular material) and other black reactive dyes. (4) Environmentally friendly reactive dyes that improve fastness. These dyes include Cibacron Light dyes, Sumifix Supra HF and NF series dyes, Kayacion E-LE and AP dyes for printing. Their perspiration-sunlight fastness reaches Level 3~4 and above. Sulfur dyes Commonly used sulfur dyes are not allergic dyes, carcinogenic dyes or acutely toxic dyes. They do not contain heavy metals and adsorbable organic halides. They use less salt during application and consume much less water and energy than reactive dyes. Therefore, sulfur dyes are also One of the alternative dyes to banned dyes, especially black. However, when dyeing with sulfur dyes, it is necessary to add sodium sulfide and alkali to reduce it. The wastewater contains 15% to 20% sulfide and the hydrogen sulfide odor generated during the manufacture and application of sulfur dyes has brought serious environmental and ecological consequences. pollution problem. Diresul RDT dye produced by Switzerland’s Clariant Company is a 20% pre-reduced sulfur dye solution that uses glucose and alkali, which are environmentally and ecologically harmless, as reducing agents instead of sodium sulfide and alkali. The sulfur content is 0.7%~ 4.0%, almost no hydrogen sulfide odor. Since the new dyes greatly reduce the sulfide content in the wastewater, they consume less water, and the wastewater treatment is simple. Moreover, hydrogen peroxide, bromate or peroxodisulfate is used as the oxidant during oxidation , and the oxidation wastewater is also easy to treat. The company’s Diresul EV new environmentally friendly sulfur dye has a sulfide content of less than 50 mg/L and a reducing agent that is 1/3 of the conventional dosage. The sulfide content in wastewater is greatly reduced, and the COD value of wastewater is also greatly reduced. In addition, the company uses sulfite to treat sulfur dye oxides and introduce thiosulfate groups – SSO3 to make Sandozol T-type environmentally friendly sulfur dyes. Their sulfide content is actually “zero”, they are water-soluble, and their solutions are neutral. But they have no affinity for cellulose fibers and are mainly used for leather dyeing. In addition, James Robinson’s pre-reduced sulfur dye leuco solution, DyStar’s sulfur dyes with low sulfide content such as Cassulfon Black C-BRV, Cassulfon Carbon CMRV, etc. are all environmentally friendly sulfurization that is beneficial to the environment and ecological protection. dye. Vat dyes Vat dyes do not contain azo dyes that can break down under specific conditions to produce 22 carcinogenic aromatic amines. They are not allergic dyes, carcinogenic dyes or acutely toxic dyes. They do not contain environmental hormones, and the chromaticity of the wastewater when used is low, so they are banned. An alternative to dyes. However, from the perspective of environmental and ecological protection requirements, vat dyes have many manufacturing steps and complex synthesis reactions. Sometimes organic halides such as polychlorbenzene are used as solvents and heavy metals and their derivatives are used as catalysts. Therefore, their pollution to the environment and ecology has always been a problem. issues of public concern. BASF’s Indanthren Colloisol dyes, Ciba Refinery’s Cibanone MD dyes, Bezema’s Benzathren micro dyes and Mitsui-BASF’s Mikethrene s/f dyes have all met the requirements for environmentally friendly dyes. Shanghai Dye Company’s SM type vat dyes not only do not contain banned dyes, but the content of heavy metals that can be extracted is below the limit value, and they do not contain environmental hormones or chemicals that pollute the environment. They are also an environmentally friendly alternative to banned dyes. type vat dye. Cationic dyes Cationic dyes are special dyes for polyacrylonitrile fibers. During the manufacturing process of cationic dyes, zinc chloride is usually used to precipitate the double salt. The zinc content in its products is very high, generally 15% to 20%. ETAD clearly stipulates that zinc is one of the heavy metals that need to be controlled in dyes. Therefore, the development of environmentally friendly cationic dyes is mainly about the zinc content in dyes. Through technological transformation, the new manufacturing technology no longer uses zinc chloride, but uses other environmentally and ecologically harmless precipitants. The cationic dyes produced in this way meet the requirements of environmentally friendly dyes, such as Viocryl Red GRLS from the British D&G Dyes Company. ZF 200%, Viocryl Navy FBL ZF, Viocryl Black FL ZF 200%, etc. are all zinc-free cationic dyes. Understanding of dyes Regarding the issue of environmentally friendly dyes, many manufacturers, especially dye users, have a misunderstanding that all azo dyes are non-environmentally friendly dyes. This is not the case. Rather, azo dyes that contain carcinogenic components or 22 dye intermediates that break down into carcinogenic substances are non-environmentally friendly dyes. Banned dyes In recent years, the international community has been very concerned about the deterioration of environmental quality and the imbalance of ecological balance. Humanity is facing the most serious environmental crisis in history. Most of the environmental pollution is directly related to the pollution of industry and industrial products. Aromatic amines, which are dye intermediates, have been listed as suspected carcinogens by government agencies in some countries . Among them, benzidine and ethylnaphthylamine have been confirmed to be the most potent carcinogens to humans. For this reason, in countries around the world, paying attention to dye production and emphasizing environmental protection has become a top priority. The United States, Europe, and Japan have established institutions to study the ecological safety and toxicology of dyes, specializing in understanding and studying the impact of dyes on human health and the environment, and Indicators for heavy metal content in dyes were formulated. The Ecological Committee of the American Dyestuff Manufacturers Association independently studies the environmental impact of dyes and auxiliaries and determines the concentration range of metal impurities in various types of commercial dyes . In April 1992, Germany wrote about banned dyes in the first article of the daily necessities law, but it was not clear, so it was released in July 1994, December 1994, July 1995, and July 1996. The second to fifth amendments were adopted, and more detailed supplementary announcements on relevant provisions were made in July 1997. According to an analysis by the German Bayer Company in 1994, there were 118 banned dyes in the German market. According to their application categories, they included 77 direct dyes , 26 acid dyes, 6 disperse dyes, 5 ice dye bases, and basic dyes. 3 pieces and 1 piece of oxidized color base. In the 1999 SDC resource file, there were 141 azo dyes collected by the German VCI (German Chemical Industry Association) based on internal research and the 1994 third edition of the “Dye Index” that can reduce and cleave 22 carcinogenic aromatic amines. Compared with the 118 banned dyes proposed by the German Bayer Company in 1994, 113 dyes have the same structure. If the banned dyes proposed by VCI and Bayer are combined, there will be a total of 146 banned dyes, including 84 direct dyes, 29 acid dyes, 9 disperse dyes, 7 basic dyes, 5 ice dye bases, and oxidation colors. 1 base, 2 mordant dyes and 9 solvent dyes. According to the new version of Eco-Tex Standard 100 released in 2000 for testing toxic substances in textiles, the banned dyes involved also include allergenic dyes, direct carcinogenic dyes and acutely toxic dyes, as well as lead, antimony, chromium, and cobalt. , copper, nickel, mercury and other heavy metals exceeding the limit, formaldehyde content exceeding the limit, dyes containing organic pesticides exceeding the limit, as well as dyes containing environmental hormones, chemical substances that cause environmental pollution, variability chemicals, and persistent organic pollution Material dyes, etc. Analysis of the molecular structure of dyes and actual measurements of dyed fabrics indicate that dyes synthesized from carcinogenic aromatic amines as intermediates, including azo dyes and other dyes, are banned even if they are present in trace amounts without sufficient purification. Currently, about 70% of the synthetic dyes on the market are based on azo structures. The widely used direct dyes, acid dyes, reactive dyes, metal complex dyes, disperse dyes, cationic dyes and condensation dyes all contain azo structures. . Azo dyes are not only used for printing and dyeing textiles, but also for dyeing leather, paper, food, etc. It should be pointed out that under normal circumstances, azo dyes themselves will not have harmful effects on the human body. However, some azo dyes synthesized with carcinogenic aromatic amine intermediates will interfere with the normal metabolism of the human body after long-term contact with human skin. The substances released in the compound combine and undergo a reduction reaction to cleave the azo group and regenerate carcinogenic aromatic compounds. These compounds are reabsorbed by the human body and undergo activation to cause changes in the structure and function of human cells, thereby transforming into human pathological changes. predisposing factors, thereby increasing the likelihood of carcinogenesis. At the same time, banned dyes are not limited to azo dyes. Dyes with other structures, such as sulfur dyes, vat dyes and some auxiliaries, may also be banned due to the presence of harmful aromatic amines. direct dyes Direct dyes are the largest type of dyes used in cellulose fibers. Among the first batch of 118 banned dyes in Germany, direct dyes account for 77, accounting for 65%. Among them, there are 72 direct dyes synthesized using benzidine, dimethylbenzidine and other three types of derivatives as intermediates, and 36 direct dyes using benzidine as an intermediate alone. The output accounts for almost 50% of the total direct dye output. . According to statistics, there are 37 banned direct dyes among the direct dyes produced in my country in recent years, accounting for 62.7% of the total number of direct dyes produced in my country. Acid Dyestuff The consumption of acid dyes in the world is second only to sulfur, direct and disperse dyes. Among the dyes banned in Germany, there are nearly 30 acid dyes. There are many types of harmful aromatic amines involved, including benzidine, dimethylbenzidine, o-aminoanisole, o-toluidine, p- aminoazobenzene, and 4-amino-3,2-dimethylazo Benzene and dyes themselves cause cancer, etc. Inside. The chromatogram is mainly concentrated in red and black, and the others are distributed in orange, purple, brown and other chromatograms. Including: weak acid orange R (acid orange 45), weak acid red H ( acid red 285), acid black NT29 (acid black 29), etc. In addition, there are 4 new banned acid dyes in the new version of Eco-Tex Standard 100 released in 2000: there are 2 known direct carcinogenic dyes, they are CI acid red 26 and CI acid violet 49; The allergenic dye is CI Acid Black 48; the acute toxic dyes involved are CI Acid Orange 156, CI Acid Orange 165, etc. Disperse dyes Among the 118 dyes banned in Germany, a total of 6 disperse dyes are banned. Disperse dyes are not listed but are banned due to the influence of 22 harmful aromatic amines. According to incomplete statistics, there are 14 types, not including those used as compounds. The composition of the dye is included. Prominent among the banned dyes is CI Disperse Yellow 23, which is a red-yellow disazo disperse dye. Our country’s trade name is Disperse Yellow RGFL . Several other banned disperse dyes include: Disperse Yellow E-5R (CI Disperse Yellow 7), Disperse Orange 2G (CI Disperse Yellow 56), CI Disperse Orange 149, CI Disperse Red 151, CI Disperse Blue 1, etc. In the new edition of Eco-Tex Standard 100 released in 2000, disperse dyes accounted for 26 types of allergenic dyes involved. In addition, there are two types of disperse dyes among known carcinogenic dyes, namely CI Disperse Yellow 3 and CI Disperse Blue 1. Chromophores and phenols Many of the color bases used in insoluble azo dyes are carcinogenic or suspected carcinogenic aromatic amines of MAK(Ⅲ)A1 (MAK means maximum workplace concentration) and A2 groups, which should be banned. There are a total of 5 banned color bases announced by Germany in the first batch, and one color base is omitted. According to incomplete statistics, there are 9 kinds of naphthols synthesized from harmful aromatic amines. In addition, there are color groups containing isomers that are harmful aromatic amines, such as orange-based GC (CI color base 2) and yellow-based GC (CI color base 44), which are m-monochloroaniline and o-chloroaniline respectively. Chloroaniline is an isomer of p-chloroaniline, a carcinogenic aromatic amine. Several other prohibited color bases: red base TR (CI ice dye base 11), big red base G (CI ice dye base 12), blue base B (CI ice dye base 48), dark blue base R (CI ice dye base 48) 113) and maroon-based GBC (CI ice dye base 4), etc. There is only one oxidative chromogen included in the banned dyes in Germany, which is CI chromogen 14, or CI oxidative chromophore 20 (76035), which is 2,4- diaminotoluene . The acutely toxic dyes involved are CI Chromogen 20, CI Chromogen 24 and CI Chromogen 41. Basic dyes There are three basic dyes included in the first batch of banned dyes in Germany. They are: Basic Brown 4, Basic Red 42, and Basic Red 111. Among them: CI Basic Red 111 contains p-aminoazobenzene; CI Basic Red 42 contains anthranilate; CI Basic Brown 4 contains 2,4-diaminotoluene. Another four basic dyes were announced by the German VCI and were banned because they contained harmful aromatic amines. For example, CI Basic Yellow 82 contains p-aminoazobenzene; CI Basic Yellow 103 contains 4,4` -diaminodiphenylmethane ; CI Basic Red 76 contains o-aminoanisole; CI Basic Red 114 contains o-aminoanisole. Anisole. There are 6 basic dyes among the acute toxic dyes involved. They are: CI basic yellow 21, CI basic red 12, CI basic violet 16, CI basic blue 3, CI basic blue 7, CI basic. Sex blue81. Among the dyes involved, there is one basic dye known to be directly carcinogenic, namely CI Basic Red 9. Reactive dyes and vat dyes Among the 118 banned dyes, there are no two major categories of reactive and reducing dyes, but 22 harmful aromatic amines are the starting point. Individual varieties of dyes within these two categories will be affected. For example, reactive dyes include reactive yellow KR, reactive blue KD-7G, reactive yellow brown K-GR, and reactive yellow KE-4RNI. wait. Fewer vat dyes are banned, but for example, Vat Brilliant Pink R (CI Vat Red 1,73360) is made from o- aniline , and Vat Red Violet RH (CI Vat Violet 2, 73385) is also made from o-aniline. , so it is also affected by the ban. The corresponding soluble vat dyes, indosodium rosé IR and indosodium red violet IRH, which are the sulfate esters of reduced rosé R and reduced red violet RH leucosomes respectively, will also be affected. Other types of dyes In addition to the above-mentioned dyes, other commonly used dyes have also become banned dyes due to the use of certain aromatic amine intermediates in their dyes. For example, among the sulfur dyes, sulfide yellow brown 5G (CI sulfide brown 10, 53055), sulfide yellow brown 6G (CI sulfide orange 1, 53050), sulfide light yellow GC (CI sulfide yellow 2, 53120), sulfide reduction black CLG ( CI sulfur black 6) and sulfur grass green ZG, sulfur dark green GH and other blended sulfur dyes. In paint pastes, dyes made with azo-containing dye structures as solids are also banned. Including permanent orange G (CI Pigment Orange 13, 21110), 8205 dye golden FGRN, 6103 dye golden FG and 8111 dye red FFG, etc. Economic impact The deep spread of the financial crisis to economic entities has caused China’s dye industry to encounter unprecedented challenges. In 2008, there was a major turning point in the development of the industry. The output of dyes and organic pigments experienced negative year-on-year growth for the first time. The output of major production enterprises fell back to varying degrees, and their profits also dropped significantly. This year, the overall development trend of the dye industry has not fundamentally changed. In response to a once-in-a-century crisis, my country’s dye industry has come out of its trough, and it is urgent to actively adjust its business and development ideas. Looking for “opportunities” in “crisis” Currently, there are two things that my country’s dye companies need to pay attention to. First, strengthen brand building and develop specialty products. China’s dye output accounts for more than 60% of the world’s output, but its market share is less than 35%. A considerable number of dyes are sold under OEM brands, and are only made in China without Chinese brands. Due to the lack of brand, China is a big dye producing country rather than a powerful country. In the face of the global financial crisis , purchasing power has declined, and the demand for cheaper goods has increased due to reduced income. Therefore, during the crisis, the demand for mid- to low-end products may be more stable. Cheaper Chinese dye brands will be more easily accepted and recognized when introduced to the market. At the same time, we can also buy international brands at the bottom, and have the right to speak and set prices for Chinese brands by taking shares or holding shares. The second is that enterprises with strength should “go global”. The financial crisis will bring about a new round of international industrial transfer opportunities. Chinese dye companies can take advantage of this opportunity to go global and invest in countries where the textile printing and dyeing industry is developing rapidly, the market demand for dyes is large, and dyes and chemicals are underdeveloped. We should proactively invest and produce some competitive, environmentally friendly and safe products overseas through joint ventures, cooperation and other means. The good news is that some domestic companies have already set up joint ventures overseas, and some are currently negotiating. Control the total quantity and eliminate backwardness Controlling the total quantity and eliminating backwardness are of great significance to the short-term and long-term development of China’s dye industry. China’s annual dye production has now reached 700,000 tons. Such a high dye production and such a high share in a country or region has never been seen in the history of the development of the dye industry. This will inevitably bring about total excess, environmental pressure and energy pressure, so it is imperative to eliminate backward production capacity. The market shrinks under the crisis situation, and it is inevitable for the market to be reshuffled. We must adjust corporate structures, accelerate industrial upgrading, integrate industry resources, and carry out mergers and reorganizations to make advantageous companies bigger and stronger. Only through unity can we have strength, only through unity can we have stamina, and only through unity can we develop. In the process of reform and opening up, a large number of private dye enterprises have been cultivated and developed. In the baptism of the current crisis, a number of large-scale dye groups with strong comprehensive strength, high market share, their own national brands, and independent intellectual property technologies will surely emerge. Build confidence in dealing with crises While fully estimating the severe challenges posed by the financial crisis, we must build confidence and see the strong conditions and opportunities for us to respond to the crisis. First of all, in the face of the economic crisis, the dye industry will not be defeated, let alone eliminated. With the advancement of social civilization and the improvement of living standards, consumers will have higher demands for supporting dye products, and the future development of the dye industry is bright. Secondly, although the export market has shrunk and external demand has dropped significantly, the world’s largest textile production and consumption is in China, and the world’s largest dye consumption market is in China. In order to stimulate domestic demand and protect the growth of the textile industry , the government has introduced many supporting policies, which will have a certain effect on boosting domestic demand for dyes. Secondly, the government actively responded to the financial crisis, acting quickly and with heavy blows. Quickly and timely adjust economic policies to ensure stability and growth. The China Dyestuff Industry Association will actively negotiate with the Ministry of Commerce, the Ministry of Environmental Protection, the Ministry of Industry and Information Technology, the Ministry of Science and Technology, the State Administration of Taxation and other relevant government departments to resume export tax rebates for dye products , establish major key technology projects in the dye industry, and implement special plans for the revitalization of the dye industry. motion. These will create favorable conditions for building confidence and maintaining growth in the dye industry.
An offset printing press is a type of lithographic printing press . During printing, the printed images and text are first printed from the printing plate onto the rubber cylinder, and then transferred to the paper by the rubber cylinder. Offset printing machines can be divided into sheet-fed offset printing machines and web-fed offset printing machines according to different paper feeding methods; according to the number of printing colors completed in one paper pass, they can be divided into single-color, two-color, four-color and multi-color printing machines; according to the printing substrate The maximum paper format can be divided into small offset printing presses , six-open, four-open, half-open and full-sheet printing presses. In addition, there are double-sided printing presses that can complete two-sided printing at the same time in one paper pass. Sheet-fed offset printing press is a lithographic printing press , used for printing high-grade commercial prints and packaging prints, and is the mainstream of modern paper printing. development path birth In 1904, Mr. Caspar Hermann of Germany was trying to improve lithographic printing technology, trying to find a new production method through countless experiments. The American Mr. Ella Washington Roubaix got involved in this research work by accident. During a printing job, Ira Washington Roubaix noticed that a piece of paper did not travel along the normal path during the printing process. He tried to print patterns on both the front and back of the paper. The image was first transferred from the printing plate to On the blanket of the impression cylinder , and then onto the paper. An unexpected scenario occurred: This indirect imprinting method produced a product with higher printing quality, and the elastic blanket surface transferred the ink to the paper more evenly. The printing method developed simultaneously by Caspar Hermann and Ira Washington Roubaix was born. This is the origin of what we often call offset printing. They separately designed sheet-fed offset printing equipment, but it was not immediately commercialized. It was not until 1912 that the world’s first web offset printing equipment, Universal, was launched, with a speed of 8,000 sheets/hour, and the offset printing machine was truly recognized by the world. prototype In 1911, KBA and Manroland , which had decades of experience in the production of letterpress and gravure printing machines , developed their first offset printing machines. From then on, they began to make more attempts in the field of printing. In the 1920s, companies such as Manroland, KBA, and Komori all launched their own sheet-fed and web-fed offset printing equipment. In cooperation with related companies, we have developed various automated printing equipment with paper delivery units, refrigeration units, folding and drum drying components. In 1932, KBA (Radebeul Company) launched the world’s first four-color sheet-fed offset printing press, Planeta-Deca, which took offset printing technology a big step forward. World War II destroyed many factories, and the development of offset printing technology was also affected, stagnating for more than ten years. In the 1940s, the boom in American newspaper production and mass circulation further promoted the advancement of offset printing technology. After 1945, offset printing made it possible to achieve high quality and high requirements for commercial advertising. In contrast, producing four-color continuous-tone images using letterpress printing techniques became expensive and time-consuming. As the industry’s demand for image and printing quality continues to increase, offset printing technology has made new breakthroughs. growing up In the 1950s, printing technology emerged one after another and developed rapidly. The emergence of imagesetters broke the 540-year printing history of movable type typesetting for the first time and led to the emergence of digital image and text typesetting. Especially the emergence of the second generation imagesetters in 1954 made the typesetting technology Go to the next level. In 1956, the emergence of prefabricated photosensitive plates (PS plates) and plate-making equipment made offset printing technology a fish in water. At the same time, the demand for offset printing technology increased significantly. In the 1950s, manroland, KBA, Komori, Akiyama, etc. successively developed their own two-color and four-color offset printing equipment. In the 1960s, the issue of ink balance during the printing process became the key to the development of offset printing technology. He invented alcohol dampening solution, and since the advent of the Dahlgren continuous dampening system in 1960, offset printing has begun to reach the level of clarity achieved by letterpress printing and compete with mature letterpress printing for the market. In 1962, Heidelberg launched KOR, an offset printing machine modified from a letterpress printing machine, on drupa, thus entering the offset printing market. The emergence of small offset printing equipment such as KOR, as well as the ABDick350 and 360 series of small offset printing machines, attracted a large number of offset printing machine users. Most of them are small printing companies, which drives the rapid development of offset printing on a global scale. At this stage, various offset press manufacturers continued to launch new offset presses. In 1965, KBA made a huge breakthrough in sheet-fed offset printing technology and produced the world’s first unit-type and double-diameter imprinting and paper transfer machines. Cylinder printing press, this design was adopted and is still the mainstream form of sheet-fed printing press today. Although the offset printing process had not yet been widely adopted around the world at this time, a considerable number of people had realized that it was a better quality and more accurate printing method. In the 1970s, commercial printing began to develop vigorously. Printing technology (color printing system) developed towards automatic high-end color separation technology and full-page typesetting design system. It gradually bid farewell to photographic color separation and manual color separation, making color images easier to transmit and Realize “what you see is what you get”. Although the color printing system is expensive and cannot be widely used in printing plants, it has been concluded that it is the future development direction of offset printing technology. The electrostatic printing introduced by Xerox at that time also pushed offset printing technology to a new level in a sense. The convenience and speed of electrostatic printing are particularly suitable for the needs of short-run printing, forcing printer manufacturers to keep up with market demand and focus on To improve the printing speed and automation of the equipment. Therefore, in the offset printing presses launched during this period, the unit printing press, button control and mechanical automatic ink supply system became standard configurations, and the printing speed was also improved. At this time, various offset printing rookies continued to appear. In 1971, Akiyama originally designed and developed a 3-diameter impression cylinder and a four-open, four-color machine Hi-Ace426 with a speed of 10,000 sheets per hour; in 1972, Manroland produced the first modular machine Printing press – Rondoset offset press and the first ROLAND 800 sheet-fed offset press with ink compensation control system, its printing speed can reach 10,000 sheets per hour, and the launch of COLORMAN, the largest rotary printing press in Europe at the time; in 1974, Heidelberg Launched the first model of a new generation of printing presses – the Speedmaster 72V four-color offset press ; in 1974, KBA (Planeta) launched the world’s first sheet-fed offset press with eight units. Rapid development In the mid-1980s, printing plants began to use computers to control the printing process. Most of the offset presses in this era realized automation of ink transfer, dampening, registration adjustment and plate reading, simplifying operations and improving printing efficiency. The application of computers in offset printing and the advent of film output machines have greatly improved the working efficiency of offset printing machines. Many offset printing machines launched in the 1980s were equipped with ink remote control systems, computer-controlled pre-inking systems, dampening unit control, alcohol-free dampening, color control systems, flipping devices, etc. Representative models include Heidelberg GTO52 and Akiyama HA1P40. , Hi-Ace432 and Bestech32, Komori Riselong L40, etc. as examples. It is worth mentioning that in 1985, KBA produced the Rapida 104, the world’s first split sheet-fed offset press with a printing speed of 15,000 sheets/hour. In the 1990s, the birth of the direct-to-plate system (CTP) was the most important contribution to offset printing technology, bringing the work efficiency and application of offset printing machines to unprecedented levels. Offset presses are more automated and digital technology is more widely used. The highlight of this period was the GTO-DI, the world’s first on-machine direct-to-plate printing press jointly launched by Presstek and Heidelberg at the Print 91 Chicago Print Show, which represented the future development direction of short-run offset printing. At IPEX 98, the Heidelberg Speedmaster SM 74 DI direct imaging offset press was exhibited for the first time and caused a sensation around the world. Today, these configurations may no longer seem new, but at the time it was comparable to laser printers and met the needs of on-demand color printing. Even on drupa 2000, many printing press manufacturers launched their own DI solutions. In 1997, KBA launched the Compacta 215, the world’s first commercial web offset press that fully adopted shaftless technology, which was also an important breakthrough in the development of web offset presses. Since then, shaftless technology has been widely used in web offset presses. Heidelberg CP Window, the world’s first fully digital printing control system, also met users at drupa1990. At this stage, the offset printing press products launched by major manufacturers have become more mature and complete, and have begun to develop in the direction of multi-color groups and multi-functions, making multi-color group double-sided printing, connected varnishing and drying no longer just a dream. Manroland launched the Roland 700 and Roland 300, medium-sized machines with a printing speed of 15,000 sheets/hour, and the Roland 900, a large-format sheet-fed offset press with an innovative concept; Komori was the first in the world to develop the Komori fully automatic plate changer (Full-APC) ; The new production line of Heidelberg Speedmaster SM74 offset printing press strives to dominate the four-format (52cm × 74cm) printing market; KBA launches the first ten-color (five-to-five) Rapida printing press; Akiyama designs and develops a unique high-performance roller arrangement , high efficiency, high value-added Jprint type sheet-fed double-sided printing press; Komori developed multi-color double-sided offset printing machine LITHRONE 40SP, etc. Classification Offset printing machines can be divided into single-color, two-color, four-color and multi-color printing machines according to the number of printing colors completed in one paper pass. According to the maximum paper format that can be printed, it can be divided into small offset printing presses, six-open, four-open, folio and full-sheet printing presses. In addition, there are also double-sided printing presses that can complete two-sided printing at the same time in one paper pass. According to the dampening system, it can be divided into alcohol machine (that is, the offset printing machine with alcohol dampening version), water truck (that is, the offset printing machine with water dampening version) and waterless offset printing machine. future The offset printing technology jointly invented by the German Caspar Hermann and the American Ella Washington Roubaix triggered a complete revolution in offset printing technology. This breakthrough enabled the offset printing technology to develop for a hundred years and occupy the entire The printing industry produces 70% of the market. As a technology that has lasted for a hundred years and is constantly improving, the development of offset printing technology is closely related to the development of the global economy and the progress of mankind. A hundred years of history have made it more mature and exciting.
Pigments are substances that give colors to objects. Pigments are divided into soluble and insoluble, inorganic and organic. Inorganic pigments are generally mineral substances. Humans have long known the use of inorganic pigments, using colored earth and ores, to paint on rock walls and smear their bodies. Organic pigments are generally derived from plants and marine animals, such as mozambique, garcinia and purple extracted from shellfish in ancient Rome. Introduction Pigment is a powdery substance used for coloring. It is insoluble in water, grease, resin, organic solvents and other media, but can be evenly dispersed in these media and can color the media, and has a certain hiding power. The basic requirements for pigments used in art are that the finer the particles, the better, the brighter the color, the better, and the longer it lasts without discoloration, the better (the stability is better). Watercolor paints Watercolor paints, except white, are almost all transparent. Only in this way can the needs of watercolor cover dyeing be met. Gouache paint was originally invented by adding white powder to watercolor paint to make the color opaque. Because watercolor paint is transparent, it is difficult to correct if you make a mistake. Gouache paint can be easily modified because it is opaque. Later, raw materials such as gum arabic were added to the gouache pigment to further improve its performance. Gum arabic can make the surface of gouache paint have a layer of luster after it dries. However, in special occasions where flat coating is required (such as rendering renderings and coloring animations), the glue will form irregular spots on the surface of the color, or make the color dull. It is uneven, so there are special degumming pigments. Oil paint is paint diluted with oil. Chinese painting pigments are very rich and come in various types, ranging from mineral powder to plant extraction to animal extraction, and the types are complex. Theoretically, as long as there are three primary colors of red, blue and yellow, all other colors can be mixed, but the purity of the mixed colors is always not high enough. Therefore, modern art paint manufacturers produce high-purity pigments for various hues and brightness colors. to meet various needs. From the most basic 12 colors to the usual 24 colors or even 48 colors to more than 60 colors. Special metallic colors are not included. use It is an indispensable raw material for the manufacture of paints, inks, oil painting pastes, cosmetic paints, colored papers, etc. It is also used for filling and coloring plastics, rubber products, and synthetic fiber solutions. Performance characteristics Pigments usually have the following properties: color. Color pigments are pigments that selectively absorb and scatter visible light energy and can present colors such as yellow, red, blue, and green under natural light conditions. Tinting power. The ability of a coloring pigment to absorb incident light. It can be expressed as a relative percentage equivalent to the tinting power of a standard pigment sample. Covering power. The ability of a film-forming substance to cover the surface color of a substrate. It is often expressed in grams of pigment contained in paint covering an area of 1 square meter. Lightfastness. The ability of pigments to maintain their original color under certain lighting conditions. Generally, an eight-level system is used, with level eight being the best. Weather resistance. The ability of pigments to maintain their original properties under certain natural or artificial climatic conditions. Generally, a five-level system is used, with level five being the best. Volatile. Mainly refers to moisture, which is generally not more than 1%. Oil absorption. Refers to the number of grams of refined linseed oil required to form a uniform mass of 100 grams of pigment. The one with the smallest oil absorption capacity is better. The oil absorption capacity is related to the specific surface area and structure of the pigment particles. water soluble matter. The water-soluble substances contained in the pigment are expressed as a mass percentage of the pigment. The water-soluble content of pigments used in paint making is often controlled below 1%. concept Pigment is a colored fine-grained powdery substance that is generally insoluble in water and can be dispersed in various media such as oils, solvents, and resins. It has hiding power, tinting power, and is relatively stable to light. It is often used in the preparation of coatings, inks, and colored plastics and rubber, so it can also be called a colorant. Pigments differ from dyes in that dyes are generally soluble in water (an old distinction), while pigments are generally insoluble in water. Dyes are mainly used for dyeing textiles and other materials. However, this distinction is not very clear, because some dyes may also be insoluble in water, and pigments are also used in pigment printing and pulp coloring of textiles. The chemical structure of organic pigments is similar to that of organic dyes, so they are usually regarded as a branch of dyes. Performance characteristics Pigments usually have the following properties: color . Color pigments are pigments that selectively absorb and scatter visible light energy and can present colors such as yellow, red, blue, and green under natural light conditions. Tinting power . The ability of a coloring pigment to absorb incident light. It can be expressed as a relative percentage equivalent to the tinting power of a standard pigment sample. Covering power . The ability of a film-forming substance to cover the surface color of a substrate. It is often expressed in grams of pigment contained in paint covering an area of 1 square meter. Lightfastness . The ability of pigments to maintain their original color under certain lighting conditions. Generally, an eight-level system is used, with level eight being the best. Weather resistance . The ability of pigments to maintain their original properties under certain natural or artificial climatic conditions. Generally, a five-level system is used, with level five being the best. Volatile . Mainly refers to moisture, which is generally not more than 1%. Oil absorption . Refers to the number of grams of refined linseed oil required to form a uniform mass of 100 grams of pigment. The one with the smallest oil absorption capacity is better. The oil absorption capacity is related to the specific surface area and structure of the pigment particles. water soluble matter . The water-soluble substances contained in the pigment are expressed as a mass percentage of the pigment. The water-soluble content of pigments used in paint making is often controlled below 1%. Basic classification Pigments can be divided into two categories based on their chemical composition: inorganic pigments and organic pigments. Based on their sources, they can be further divided into natural pigments and synthetic pigments. Natural pigments are derived from minerals, such as cinnabar, laterite, realgar, malachite green and heavy calcium carbonate, wollastonite, barite powder, talc powder, mica powder, kaolin, etc. Those from biological sources, such as those from animals: cochineal red, natural fish scale powder, etc.; those from plants include: garcinia, alizarin red, indigo, etc. Synthetic pigments are artificially synthesized, such as inorganic pigments such as titanium white, zinc barium white, lead chromium yellow, and iron blue, as well as organic pigments such as red pink, even light yellow, phthalocyanine blue, and quinacridone. Pigments are classified according to their function, such as anti-rust pigments, magnetic pigments, luminescent pigments, pearlescent pigments, conductive pigments, etc. Classification by color is a convenient and easy-to-use method. Thus pigments can be classified as white, yellow, red, blue, green, brown, purple, black, regardless of their origin or chemical composition. The famous “Dye Index” (ColorIndex) uses a color classification method: for example, pigments are divided into pigment yellow (PY), pigment orange (PO), pigment red (PR), pigment violet (PV), and pigment blue (PB). , Pigment green (PG), Pigment brown (PBr), Pigment black (PBk), Pigment white (PW), Metallic pigment (PM) and other ten categories. Pigments of the same color are arranged according to the sequence number. For example, titanium white is PW- 6. Zinc-barium white PW-5, lead chromium yellow PY-34, quinacridone PR-207, iron oxide red PR-101, phthalocyanine blue PB-15, etc. In order to find the chemical composition, there are other structural numbers, such as titanium white PW-6C.I.77891 and phthalocyanine blue PB-15C.I.74160, which allow manufacturers and users of pigments to identify the listed pigments. The composition and chemical structure of. Therefore, it has been widely used in the international pigment import and export trade industry, and some domestic pigment manufacturers also use this international classification standard for pigments. China’s national standard for pigments, GB/T3182-1995, also uses color classification. Each pigment color has a symbol, such as white for BA, red for HO, yellow for HU… Then combined with the code and serial number of the chemical structure, the pigment model is formed, such as rutile titanium white BA-01-03, medium chrome yellow HU-02-02, iron oxide red HO-01-01, zinc barium white BA-11-01, toluidine red HO-02-01, BGS phthalocyanine blue LA-61-02, etc. Pigments can be classified according to the types of compounds they contain: Inorganic pigments can be subdivided into oxides, chromates, sulfates, silicates, borates, molybdates, phosphates, vanadates, ferricyanates , hydroxides, sulfides, metals, etc.; organic pigments can be divided into azo pigments, phthalocyanine pigments, anthraquinones, indigo, quinacridone, dioxazine and other polycyclic pigments, arylmethane according to the chemical structure of the compound Department of pigments, etc. From the perspective of production and manufacturing, they can be classified into titanium pigments, iron pigments, chromium pigments, lead pigments, zinc pigments, metallic pigments, and organic synthetic pigments. This classification method has practical significance, and often one system can Represents a professional pigment production industry. From the perspective of application, it can be divided into paint pigments, ink pigments, plastic pigments, rubber pigments, ceramic and enamel pigments, pharmaceutical and cosmetic pigments, art pigments, etc. Various specialty pigments have some unique properties to match the requirements of the application. Pigment manufacturers can also recommend a series of pigment products to professional users in a targeted manner. acrylic paint Acrylic paint is a synthetic polymer pigment invented in the 1950s. It is made of pigment powder mixed with acrylic latex. Acrylic latex is also called acrylic resin polymerized latex. There are many kinds of acrylic resins, such as methacrylic resins, etc. Therefore, there are also many kinds of acrylic paints. Foreign pigment manufacturers have produced a series of acrylic products, such as matte acrylic pigments, semi-matte acrylic pigments, glossy acrylic pigments, acrylic matte oils, glazing oils, plastic ointments, etc. Acrylic paints are very popular among painters. Compared with oil paints, it has the following characteristics: 1. It can be released with water to facilitate cleaning. 2. Quick drying. The paint dries within minutes after being put down, unlike oil paintings that have to wait several months to be polished. Painters who prefer slow-drying paints can use retarder to delay the drying time of the paint. 3. The coloring layer quickly loses solubility as it dries, forming a tough, elastic, water-impermeable film. This membrane is similar to rubber. 4. The color is full, thick, and fresh, and it never feels “dirty” or “grey” no matter how you blend it. The colored layer will never absorb oil and cause stains. 5. The longevity of the piece is longer. The oil film in oil paintings is prone to oxidation over time, turning yellow and hardening, which can easily lead to cracks in the painting. Theoretically speaking, acrylic film will never become brittle or yellow. 6. The biggest difference between acrylic paint and oil painting in the way it is used is that it has the operating characteristics of general water-based paints and can be used as both watercolor and gouache. 7. Acrylic modeling ointment contains granular types, and there are coarse particles and fine particles, which provides convenience for making textures. 8. Acrylic paint is not very harmful to the human body. Just be careful not to accidentally eat it. 9. Acrylic paint can be used to design your own cultural shirts, which can highlight your personal personality. But it’s best to use cotton clothes and be white. It should be noted that acrylic painting should be painted on a base made of acrylic primer (GESSO), not an oil base. Material experts also do not advocate the mixing of acrylic and oil paints, especially not to paint oil paintings on an acrylic base. This is mainly for the permanent preservation of the work. There is no adverse reaction between acrylic and oil paints. When used alternately, their adhesion needs to be tested over time. water based pigments Water-based pigment is a new type of environmentally friendly pigment. Compared with traditional pigments, it has the advantages of non-toxic and odorless. Compared with traditional pigments, it is more in line with the concept of health and environmental protection, and has become a trend in pigments. Oil paints Oil paint is a special paint for oil paintings, which is made by mixing and grinding pigment powder with oil and glue. Most of them are sold in the market in tubes, but you can also make your own. Oil paint is a material entity formed by mixing and grinding mineral, plant, animal, chemically synthesized toner and the blending agent linseed oil or walnut oil. Its characteristic is that it can be dyed to other materials or attached to certain materials to form a certain pigment layer. This pigment layer has a certain degree of plasticity. It can form various shapes and marks that the painter wants to achieve according to the use of tools. texture. The various hues of oil paints are determined by the hue of the toner. Oil can make the hue of the toner slightly darker and more saturated. Chinese painting pigments Chinese painting pigments, also called Chinese painting pigments, are special pigments used to paint Chinese paintings. They are generally sold in tubes and paint blocks, but also in pigment powder. Classification of Chinese Painting Pigments Traditional Chinese painting pigments are generally divided into two categories: mineral pigments and plant pigments. Historically speaking, minerals should be used first, followed by plants, just like when using ink, pine smoke comes first and oil smoke comes later. The bright colors left on the ancient rock paintings were found to be made from mineral pigments (such as cinnabar). The remarkable characteristics of mineral pigments are that they are not easy to fade and are brightly colored. Most people who have seen Zhang Daqian’s splash-color paintings in his later years have this impression. , large areas of azurite, azurite, and cinnabar can refresh people’s spirits! Plant pigments are mainly extracted from trees and flowers. gouache paint Gouache is the abbreviation of gouache pigment. It has many names in China, such as advertising color, promotional color, etc. It is a kind of watercolor, that is, opaque watercolor paint. Because it is cheap, easy to learn and use, it is often used as an introductory painting material for beginners to learn color painting, and its usage simulates oil painting techniques. Performance of gouache Limitations of Purity and Brightness of Gouache Color When gouache paint is wet, its color saturation is as high as that of oil paint. But after it dries, due to the effect of the powder and the color losing its luster, the saturation is greatly reduced. This is its color. Limitations of Purity. The brightness of gouache is improved by diluting, adding powder, or using lighter colors with more powdery pigments. Its dry and wet changes are very large. Often some colors only add a small amount of powder. When wet and dry, the brightness will show a darker or lighter difference. This is the dry-wet reaction of gouache paint. Because the color of gouache generally becomes lighter after it dries, using the gouache well is the most difficult problem to solve technically in gouache painting. The pink color just makes the color of the picture full of the unique “pink” quality of gouache painting, and appears particularly rich in the middle color, but the color fineness of gouache painting is still far lower than that of oil painting. Due to the limitations of gouache paint, few large-scale works with higher specifications are created with gouache paint. Personality differences of gouache pigments Most colors of gouache pigments are relatively stable, such as earthy yellow, earthy red, ocher, orange, medium yellow, light yellow, olive green, pink green, ultramarine, cobalt blue, lake blue, etc. However, colors such as deep red, rose red, green lotus, and violet in gouache paint are extremely unstable, prone to color flipping, and difficult to cover. There are few types of transparent gouache colors, only a few colors such as lemon yellow, rose red, and green lotus. To draw a good gouache painting, you must fully grasp the personality of each gouache pigment and understand its color-receiving ability and covering ability. size, color and price. These issues require continuous practice so that practice makes perfect. Limitations of gouache There will be no unevenness when painting a large area. toxicology Regarding the toxicology of organic pigments it can be summarized that the pigments themselves are considered almost physiologically inert (safe), the health effects arise mainly from their dusty state (granular matter), due to their poor solubility. Organic pigments are actually not biodegradable. However, dispersants, binders, solvents, etc. may be used in the intermediate or final products of pigments. Under certain conditions, the toxicological effects of these substances should be considered. Toxicity sometimes results from degradation products. This degradation product of the pigment occurs when it is irradiated with laser light. For example, CI Pigment Red 22, 2-methyl-5-nitroaniline is produced by cleavage of the pigment by laser irradiation and the toxic krebseregende. Naming method Pigments are usually associated with a common name, a trade name or a color index of name (CI Common Name Nomenclature), as systematic nomenclature according to IUPAC (International Union of Pure and Applied Chemistry) or CAS (Chemical Abstracts Society) can result in unwieldy names. example: Common name: tender yellow Product name: Aureolin benzimidazolone yellow Protected Trade Name: Hostaperm Yellow H4G(TM) CI common name: CI Pigment Yellow 151 CAS Index: Benzoic acid, 2-[[1-[[(2,3-dihydro-2-oxo-1H-benzimidazol-5-yl)amino]carbonyl]-2-oxopropyl] Azo]
Titanium dioxide is an inorganic compound with the chemical formula TiO2. It is a white solid or powdery amphoteric oxide with a molecular weight of 79.866. It is non-toxic, has the best opacity, best whiteness and brightness, and is considered to have the highest performance in the world today. The best white paint. Titanium white has strong adhesion, is not prone to chemical changes, and is always white. Widely used in coatings, plastics, papermaking, printing ink, chemical fiber, rubber, cosmetics and other industries. It has a high melting point and is also used to make refractory glass, glazes, enamels, pottery, high-temperature resistant experimental vessels, etc. Titanium dioxide can be extracted from rutile by acid decomposition or obtained by decomposing titanium tetrachloride. Titanium dioxide exists in three allotropic forms in nature: rutile, anatase and plate titanium. In addition, there are several artificially synthesized crystal forms. On October 27, 2017, the World Health Organization’s International Agency for Research on Cancer released a preliminary reference list of carcinogens. Titanium dioxide is included in the list of Class 2B carcinogens. Relative density Among commonly used white pigments, titanium dioxide has the smallest relative density. Among white pigments of the same mass, titanium dioxide has the largest surface area and the highest pigment volume. Pigment name Dielectric constant Due to its high dielectric constant, titanium dioxide has excellent electrical properties. When measuring certain physical properties of titanium dioxide, the crystallographic direction of the titanium dioxide crystals should be considered. For example, the dielectric constant of the rutile type varies with the direction of the crystal. When it is parallel to the C-axis, the measured dielectric constant is 180, when it is at right angles to this axis, it is 90, and the average value of its powder is 114. The dielectric constant of anatase titanium dioxide is relatively low, only 48. Conductivity Titanium dioxide has semiconductor properties, its conductivity increases rapidly with temperature, and it is also very sensitive to oxygen deficiency. For example, rutile titanium dioxide is an electrical insulator at 20°C, but when heated to 420°C, its conductivity increases 107 times. Slightly reducing the oxygen content will have a special impact on its electrical conductivity. According to the chemical composition, the electrical conductivity of titanium dioxide (TiO2) is <10-10s/cm, while the electrical conductivity of TiO1.9995 is as high as 10-1s/cm. The dielectric constant and semiconductor properties of rutile titanium dioxide are very important to the electronics industry, which uses these properties to produce electronic components such as ceramic capacitors. Hardness According to the 10-point Mohs hardness scale, rutile titanium dioxide is 6~6.5 and anatase titanium dioxide is 5.5~6.0. Therefore, anatase type is used in chemical fiber matting to avoid wearing the spinneret holes. Application areas Industrial applications Titanium dioxide is an important white pigment and porcelain glaze. Used in paint, ink, plastic, rubber, paper, chemical fiber, watercolor pigment and other industries. Titanium dioxide is the whitest thing in the world. 1 gram of titanium dioxide can paint an area of more than 450 square centimeters snow-white. It is 5 times whiter than the commonly used white pigment – zinc barium white, so it is the best pigment for preparing white paint. The amount of titanium dioxide used as pigment in the world reaches hundreds of thousands of tons per year. Titanium dioxide can be added to paper to make the paper white and opaque. The effect is 10 times greater than other substances. Therefore, titanium dioxide must be added to banknote paper and art paper. In order to lighten the color of plastic and soften the luster of rayon, titanium dioxide is sometimes added. In the rubber industry, titanium dioxide is also used as a filler for white rubber. The photochemical properties of semiconducting titanium dioxide have made it useful in many areas such as air, water and fluid purification. Photocatalysts doped with carbon or other heteroatoms can also be used in sealed spaces or areas with scattered light sources. When used in coatings on buildings, pavements, concrete walls or roof tiles, they can significantly increase the breakdown of airborne pollutants such as nitrogen oxides, aromatics and aldehydes. Ultra-fine titanium dioxide has excellent UV-shielding properties and transparency. It is widely used in cosmetics, wood protection, food packaging plastics, durable household films, man-made and natural fibers, and clear coatings. The special optical effects in metallic glitter paints have attracted attention and application in high-end car paints. Titanium dioxide is a semiconductor with small particle size, large specific surface area, loose porous, and rough surface. It is widely used as photoanode material in dye-sensitized solar cells. Many researchers use titanium dioxide as a prototype and conduct hydrothermal method on it. , electrospinning and other methods for modification, and at the same time, metal substances, inorganic substances and other doping reactions are used to prepare photoanode with excellent performance, and then assembled into dye-sensitized solar cells. Titanium dioxide can effectively prevent the unbridled growth of microorganisms through photocatalysis, thereby reducing the amount of harmful environmental components. The antibacterial mechanism is that titanium dioxide is activated by light, and the interaction between electron hole pairs, oxygen molecules, and hydroxide ions stimulates free radicals, causing a chain reaction, destroying bacterial proteins, and achieving the sterilization effect. Food application The U.S. Food and Drug Administration stipulates that titanium dioxide can be used as a white pigment in all foods, and the maximum usage amount is 1g/kg. The pigment additive titanium dioxide can be safely used in general coloring foods, subject to the following regulations: (1) The amount of titanium dioxide does not exceed 1% of the weight of the food. (2) Colored foods shall not be used in accordance with the special standards promulgated in Article 401 of the Act, unless there are similar standards that allow the addition of pigments. (3) For colored foods, the edible pigment additive titanium dioxide can contain appropriate diluents as safe pigment additives, as follows: Silica, as a dispersing aid, the content does not exceed 2%. Product adaptability: cold fruits, jelly, fried foods, cocoa products, chocolate, chocolate products, hard candies, polished candies, gum-based candies, puffed foods, candy chocolate product coatings, mayonnaise, salad dressing, jam, solids Beverages, konjac gel foods, etc. Environmental Protection Purifying air Titanium dioxide, as a catalyst for light coating pigments, is not only an environmentally safe cleaner, but also can save energy and protect environmental resources. Early Japanese and British scientists coated titanium dioxide on the surface of paving stones on urban roads to clean the road air. Titanium dioxide can be mixed with asphalt to reduce airborne pollutants. Concrete or asphalt containing titanium dioxide can purify the air as cars pass by, eliminating 25% to 45% of nitrogen oxides in vehicle emissions. Coating titanium dioxide on the concrete surface has an equally effective air cleaning effect Cool the earth In May 2012, British scientists proposed a bold idea. They believed that the purpose of cooling the earth could be achieved by spraying enough titanium dioxide into the stratosphere to reflect sunlight. This could effectively offset the various effects of global warming. adverse climate factors. Because titanium dioxide can effectively reflect direct sunlight, has stable properties and has good hiding ability, it can work for a long time if sprayed in the stratosphere. British scientists proposed that high-altitude balloons can be used to bring this chemical into the stratosphere and then release it. Once titanium dioxide is evenly distributed in the Earth’s stratosphere, it can effectively reflect sunlight and thereby cool the Earth. Peter Davidson, a chemical engineer and president of the British consulting company Davidson Technology, is the person in charge of this project. He said that only 3 million tons of titanium dioxide need to be transported to the earth’s stratosphere to form a layer of thickness in the earth’s stratosphere. A 1mm protective layer, but the effect it can play is huge – enough to offset the greenhouse effect caused by twice the current amount of carbon dioxide in the atmosphere. Sunscreen Cosmetics Because ultraviolet rays are very harmful to the human body, developed countries have paid more attention to the research and development of sunscreen products in recent years, and have successively launched a variety of anti-UV fibers, plastics, films, coatings, as well as sunscreen creams, foundations, and lipsticks. , mousse, baking ointment and other sunscreen cosmetics. In recent years, our country has also increased the research and production of sunscreen cosmetics. However, in the past, sunscreens were mostly organic compounds such as benzophenones, o-aminobenzophenones, salicylates, para-aminobenzoic acids, and cinnamates. Therefore, they were unstable, had a short lifespan, and had serious side effects. , has certain toxicity and irritation. If added in excess, it will cause chemical allergies and may even lead to skin cancer. Nano-titanium dioxide is an inorganic component, has excellent chemical stability, thermal stability and non-migration, strong achromatic power, hiding power, low corrosiveness, good dispersibility, and is non-toxic, odorless, Non-irritating, safe to use, and also has sterilizing and deodorizing properties. More importantly, as mentioned above, nano-titanium dioxide can not only absorb ultraviolet rays, but also emit and scatter ultraviolet rays, so it has strong anti-ultraviolet ability. Compared with the same dose of organic anti-ultraviolet agents, its absorption peak in the ultraviolet region is Higher; and nano-titanium dioxide has a blocking effect on both medium-wave and long-wave ultraviolet rays, unlike organic anti-UV agents that only have a shielding effect on medium-wave or long-wave ultraviolet rays. In particular, due to its finer particles, the finished product has high transparency and can transmit visible light. When added to cosmetics, the skin will be naturally white, overcoming the shortcomings of some organic matter or pigment-grade titanium dioxide that are opaque and make the skin appear unnaturally pale. Because of this, nano-titanium dioxide quickly received widespread attention and gradually replaced some organic anti-UV agents, becoming a physical shielding anti-UV agent with superior performance in today’s sunscreen cosmetics. As people’s living standards improve and international competition intensifies, the research and development of safe and efficient sunscreen cosmetics will gradually increase. Today, the sunscreen cosmetics market in developed countries has shown strong vitality. From 1999 to 2000, annual sales in the United States reached US$737 and US$765 million respectively, and in the UK reached US$245 and 270 million respectively. In recent years, they have grown at rates of more than 20% and 10% respectively, and the amount of nano-titanium dioxide has also increased year by year. magnitude growth. The annual demand for nano-titanium dioxide in Japanese anti-UV cosmetics is more than 1,000t, and the amount used in textiles, plastics, and rubber products is even greater. Judging from the development trend of sunscreen cosmetics, one is inorganic sunscreen agents replacing organic sunscreen agents, and the other is bionic sunscreen. The latter costs more and is difficult to promote now. The former is moderately priced and has excellent sun protection properties, so it is generally favored. In particular, nanometer titanium dioxide has good development momentum and market potential due to its superior performance and application prospects.
..High Titanium Slag is commonly known as the titanium ore enrichment formed through the physical production process. The titanium ore is heated and melted by an electric furnace to melt and separate the titanium dioxide and iron in the titanium ore, which is a high-content titanium dioxide enrichment. High titanium slag is neither a waste residue nor a by-product, but a high-quality raw material for the production of titanium tetrachloride , titanium dioxide and titanium sponge products. Titanium slag is smelted from Ilmenite. status color The general state is powdery and black. The particle size is 40-200 mesh (Mesh). Supplied in powder form, the total amount of particle size between 0.425mm and 0.075mm is not less than 75%. Application areas 1. High titanium slag with a TiO 2 content greater than 90% can be used as a raw material for the production of titanium dioxide by chlorination method 2. High-titanium slag with less than 90% TiO 2 is a high-quality raw material for the production of titanium dioxide by sulfuric acid method. Prospect analysis As the global consumption of titanium dioxide and titanium sponge continues to grow, the demand for high titanium slag has been on a straight upward trend. In recent years, the annual global high-titanium slag transaction volume has exceeded US$1 billion. High titanium slag is commonly known as a titanium ore enrichment formed through a physical production process. The titanium ore is heated and melted by an electric furnace to melt and separate the titanium dioxide and iron in the titanium ore, which is a high-content titanium dioxide enrichment. High titanium slag is neither a waste residue nor a by-product, but a high-quality raw material for the production of titanium tetrachloride, titanium dioxide and titanium sponge products. In recent years, my country’s titanium dioxide and titanium sponge industries have developed rapidly. Due to the high titanium content of high-titanium slag, the production (processing) of “three wastes” is small, the utilization rate of resources and energy is high, and it can help improve product quality. my country’s high-titanium slag The demand is growing rapidly. Although the domestic production of high titanium slag is constantly expanding, it still cannot meet the strong domestic demand. my country also needs to import a large amount of high titanium slag every year to supplement the gap. my country’s high-titanium slag industry still shows a situation of insufficient supply. In the next few years, my country’s high-titanium slag will still need to be imported in large quantities. my country’s titanium slag production technology level is at the bottom in the world. The overall scale of high-titanium slag production enterprises is small and their competitiveness is not strong. In 2005, there were only about a dozen companies producing and processing high-titanium slag in China. By 2006, the number of domestic companies had increased, but the overall quality was not strong. Except for Panzhihua Iron and Steel Co., Ltd. , a large company, the rest of the companies produced The output of high titanium slag is less than 10,000 tons. In 2007, the number of companies producing high titanium slag in my country increased rapidly, growing to more than 60 companies, and the strength of the companies is growing. At the end of 2008, the Tariff Commission of the State Council issued the “2009 Tariff Implementation Plan”. According to the plan, the import of high-titanium slag (titanium dioxide mass fraction greater than 70%) (tariff number 38249099) in 2009 will continue to be reduced from the original most-favored-nation rate of 6.5% to 0 , sulfuric acid (Tariff No. 28070000) was reduced from the original MFN tax rate of 5.5% to 0. At the same time, the tentative tariff for the export of titanium ore and its concentrate (Tariff No. 26140000) in 2009 was raised to 10%. According to the direction of the above tax rate adjustment, the country’s tendency to protect resource-based raw materials is relatively obvious. After the implementation of the new tariff plan, domestic exports of titanium concentrate will be restricted, while imports of sulfuric acid and high-titanium slag should increase. There are currently about 70 titanium dioxide manufacturers in my country. Except for one in Jinzhou, which uses the chloride process, the others all use the sulfuric acid process and the raw materials used are mainly titanium concentrates. In recent years, titanium dioxide production companies have realized the advantages of high titanium slag and gradually turned to high titanium slag to produce titanium dioxide. For a long period of time in the future, titanium dioxide and metal sponge titanium products using high titanium slag as raw materials will still be key projects encouraged to develop in the adjustment of the national industrial structure. As a primary mineral product in short supply, high titanium slag has a very broad market prospect. Some relatively powerful domestic companies, such as Fengcheng Qianyu Titanium Industry Co., Ltd. , have begun to independently develop high-quality high-titanium slag. Some leading companies have invested huge capital to introduce advanced foreign technology and large-scale equipment for the production of high-titanium slag. . Increasing research and development efforts and using its technological advantages to produce high-quality, high-yield products to compete with peers and seize the market will become the biggest competitive trend in the development of the high-titanium slag industry.
..Titanium dioxide is an important inorganic chemical pigment whose main component is titanium dioxide. There are two production processes for titanium dioxide: sulfuric acid method and chlorination method. It has important uses in industries such as coatings, inks, papermaking, plastics and rubber, chemical fibers, and ceramics.
..Carbon dioxide is a carbon-oxygen compound with the chemical formula CO2 and a chemical formula quantity of 44.0095. It is a colorless and odorless or colorless and odorless gas at normal temperature and pressure, and its aqueous solution has a slightly sour smell. It is also a common Greenhouse gases are also one of the components of air (accounting for 0.03%-0.04% of the total volume of the atmosphere). In terms of physical properties, carbon dioxide has a melting point of -56.6°C (527kPa), a boiling point of -78.5°C, is denser than air (under standard conditions), and is soluble in water. In terms of chemical properties, carbon dioxide is chemically inactive and has high thermal stability (only 1.8% decomposes at 2000°C). It cannot burn and usually does not support combustion. It is an acidic oxide and has the properties of an acidic oxide. Since it reacts with water to form carbonic acid, it is an anhydride of carbonic acid. Carbon dioxide can generally be produced by calcining limestone at high temperatures or by the reaction of limestone and dilute hydrochloric acid. It is mainly used in refrigeration of perishable food (solid state), as refrigerant (liquid state), in the manufacture of carbonized soft drinks (gaseous state) and as a solvent for homogeneous reactions ( supercritical state), etc. Regarding its toxicity, research shows that low concentrations of carbon dioxide are not toxic, while high concentrations of carbon dioxide can poison animals. On April 13, 2023, the 742nd Academic Symposium of the Xiangshan Science Conference was held. Experts pointed out that carbon dioxide utilization technology has huge potential. As of June 2023, global greenhouse gas emissions have reached a “record high” in the past 10 years, with up to 54 billion tons of carbon dioxide emitted annually. Molecular Structure The shape of the CO2 molecule is linear, and its structure was once thought to be: O=C=O. However, the carbon-oxygen bond length in the CO2 molecule is 116pm, which is between the carbon-oxygen double bond (bond length 124pm) and the carbon-oxygen triple bond (bond length 113pm), so the carbon-oxygen bond in CO2 has a certain degree of triple bond length. key characteristics. Modern scientists generally believe that the central atom of the CO2 molecule, the carbon atom, adopts sp hybridization. The two sp hybrid orbitals overlap with the 2p orbitals (containing one electron) of the two oxygen atoms to form two σ bonds. The p atoms on the carbon atoms are perpendicular to each other. The orbitals then form two large π bonds with the parallel p orbitals of the two oxygen atoms. Generating pathway Carbon dioxide gas is part of the atmosphere (accounting for 0.03%-0.04% of the total volume of the atmosphere). It is abundant in nature. Its main production pathways are as follows: ① Organic matter (including animals and plants) decomposes, ferments, decays, and deteriorates. Carbon dioxide can be released during the process. ② Carbon dioxide is also released during the combustion of petroleum, paraffin, coal, and natural gas. ③Petroleum and coal also release carbon dioxide during the production of chemical products. ④ All feces and humic acid can also release carbon dioxide during fermentation and maturation. ⑤All animals inhale oxygen and exhale carbon dioxide during respiration. Preparation Industrial preparation Calcination method The carbon dioxide gas produced during the high-temperature calcining of limestone (or dolomite) is washed with water, impurities removed, and compressed to produce gaseous carbon dioxide. Fermentation gas recovery method The carbon dioxide gas produced during the fermentation process of ethanol production is washed with water, impurities removed, and compressed to produce carbon dioxide gas. By-product gas recovery method The production process of ammonia, hydrogen, and synthetic ammonia often involves a decarbonization (ie, removal of carbon dioxide from the gas mixture) process, so that high-purity carbon dioxide gas can be obtained by absorbing the carbon dioxide in the mixed gas under pressure and heating and desorbing under reduced pressure. adsorption expansion method Generally, the by-product carbon dioxide is used as the raw material gas, and high-purity carbon dioxide is extracted from the adsorption phase using the adsorption expansion method, and the product is collected with a cryogenic pump; it can also be produced by adsorption distillation, which uses silica gel, 3A molecular sieve and activated carbon as adsorbents. , remove some impurities, and produce high-purity carbon dioxide products after distillation. Charcoal kiln method Carbon dioxide is refined from carbon kiln gas and methanol cracking gas. Main Application High-purity carbon dioxide is mainly used in the electronics industry, medical research and clinical diagnosis, calibration gas for carbon dioxide lasers, testing instruments and the preparation of other special gas mixtures. It is used as a regulator in polyethylene polymerization reactions. Solid carbon dioxide is widely used to refrigerate dairy products, meat, frozen foods and other perishable foods in transit. It is used as a refrigerant in many industrial processes, such as crushing heat-sensitive materials, rubber polishing, metal cold processing, and shrink assembly of mechanical parts. , vacuum cold trap, etc. Gaseous carbon dioxide is used for carbonization of soft drinks, pH control in water treatment processes, chemical processing, food preservation, inert protection of chemical and food processing processes, welding gas, plant growth stimulant, in casting for hardening molds and cores and for Pneumatic devices are also used as diluents for sterilizing gas (i.e., mixed gases of ethylene oxide and carbon dioxide are used as sterilizing, insecticide, and fumigant) and are widely used in the sterilization of medical equipment, packaging materials, clothing, fur, bedding, etc. , bone meal disinfection, fumigation of warehouses, factories, cultural relics, books). Liquid carbon dioxide is used as a refrigerant, for low-temperature testing of aircraft, missiles and electronic components, to enhance oil well recovery, for rubber polishing and to control chemical reactions, and as a fire extinguishing agent. Supercritical carbon dioxide can be used as a solvent to dissolve non-polar, non-ionic and low molecular weight compounds, so it is widely used in homogeneous reactions. Security Measures Natural Environment Natural greenhouse effect: Greenhouse gases such as carbon dioxide in the atmosphere can radiate longer-wavelength long-wave radiation to the ground after strongly absorbing long-wave radiation from the ground, which plays a role in insulating the ground. Enhanced greenhouse effect: Since the industrial revolution, human activities have emitted large amounts of carbon dioxide and other greenhouse gases, causing the concentration of greenhouse gases in the atmosphere to rise sharply, resulting in an increasingly enhanced greenhouse effect. [43] According to statistics, before industrialization, the global annual average atmospheric carbon dioxide concentration was 278ppm (1ppm is one part per million). In 2012, the global annual average atmospheric carbon dioxide concentration was 393.1ppm. By April 2014, the atmospheric concentration in the northern hemisphere was 393.1ppm. The average carbon dioxide concentration exceeded 400ppm for the first time. Global warming: The continuous intensification of the atmospheric greenhouse effect has led to global warming, resulting in a series of global climate problems that are unpredictable by today’s science. The International Climate Change Economics Report shows that if humans continue to maintain the current lifestyle, there will be a 50% chance that the global average temperature will rise by 4°C by 2100. If the global temperature rises by 4°C, the glaciers in the Arctic and Antarctic will melt, and sea levels will rise. More than 40 island countries and the most populous coastal cities in the world will be in danger of being submerged. Tens of millions of people around the world will be inundated. Life will face crises, and even global ecological balance disorders will occur, eventually leading to large-scale migration and conflicts around the world. Human Health Studies have shown that when the concentration of carbon dioxide in the air is less than 2%, there is no obvious harm to humans. If the concentration exceeds this concentration, it can cause damage to human respiratory organs. That is, carbon dioxide is generally not a toxic substance, but when the concentration of carbon dioxide in the air exceeds a certain limit, Sometimes, the body will be poisoned, and high concentrations of carbon dioxide will make people suffocate. Animal experiments have proven that in air with normal oxygen content (20%), the higher the concentration of carbon dioxide, the higher the mortality rate of animals. At the same time, animal death caused by pure carbon dioxide is more rapid than death caused by lower oxygen. In addition, some people believe that under low oxygen conditions, carbon dioxide with a concentration of 8% to 10% can cause death of humans and animals in a short period of time.
..River sand is a non-metallic ore produced by repeated collision and friction of natural stone under the force of water for a long time in its natural state . Its composition is relatively complex, the surface has a certain smoothness, and it is a non-metallic ore with high impurity content . River sand has smooth particles, is relatively clean, and comes from a wide range of sources; river sand has no taste, while sea sand has a salty taste. type River sand is currently divided into: river sand 4-8 mesh, river sand 8-16 mesh, river sand 10-20 mesh, river sand 20-40 mesh, river sand 40-70 mesh, river sand 70-100 mesh. contribute River sand has made outstanding contributions to the construction industry. But sea sand is the opposite. Sea sand is often mixed with shells and salt. Most sea sand contains excessive chloride ions , which will corrode the steel bars in reinforced concrete , eventually leading to the destruction of the building structure and shortening the safe use of the building to a certain extent. life. use After drying and screening, river sand can be widely used in various dry mortars ; for example, thermal insulation mortar , bonding mortar and plastering mortar use washed, dried and graded river sand as the main aggregate. The strength is similar to mortar made of quartz sand . Therefore, river sand generally plays an irreplaceable role in construction and decoration! reduce On August 19, 2019, a recent comment published in the British magazine Nature stated that the rate of sand and gravel extraction has exceeded the rate of natural recovery. It is reported that sand and gravel are already the most mined raw materials. About 32 billion tons to 50 billion tons of sand are used around the world every year, mainly used to make cement, glass and electronic products. Although deserts make up 20% of the Earth’s land surface , their sand is too smooth to be used. The vast majority of angular sand suitable for industrial use comes from rivers – which occupy less than 1% of the earth’s surface.
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