By Lzh | 06 February 2023 | 0 Comments
Why chromium oxide has stable crystal form and high melting point?
What is chromium oxide?
The molecular formula of chromium oxide is Cr203 oxide, with a molecular weight of 152, dark grass green crystalline powder, a relative density of 5.21, a melting point of 1990 ℃, insoluble in water, slightly soluble in acid, and magnetic. Common chromium compounds include yellow-green crystal potassium dichromate K2Cr207 with a relative density of 2.7, yellow crystal potassium chromate K2Cr04 with a relative density of 2.5, yellow crystal sodium chromate Na2CrO4 · 10H2O, yellow crystal lead chromate PbCr04. The above chromium salts are decomposed into Cr203 under a reducing atmosphere; It is the colored oxide of green glass; Under the condition of strong oxidation, the amount of high-valent chromium CrO3 is more, which makes the glass yellow and green; In a strong alkaline glass (such as high lead glass), the glass is colored yellow mainly by Cr03. Cr203 and CuO share an area of pure green. In producing bottles and jars, cheap chromium slag (the residue after chromite production) is often used. In the production of ceramics, it is suitable for manufacturing green glaze, red glaze (adding basic lead chromate 2PbO · PbCr04), gray glaze (adding ZnO), and yellow sleeve (adding TiO2). It is the raw material for manufacturing green color cement.
Use of chromium oxide
Chromium oxide is widely used as ceramic coatings and refractories because of its stable crystal shape and high melting point. Ceramic coatings have excellent wear resistance, corrosion resistance, and heat resistance. Generally speaking, there are certain differences in physical and chemical properties between ceramic coatings and metal substrates, Especially the difference in linear expansion coefficient between the two. This difference causes sudden changes in the structure and performance of the interface between the coating and the substrate, resulting in large residual stress and thermal stress in the coating, which will cause the coating to fall off. C203 coating has the characteristics of high thermal conductivity, low coefficient of thermal expansion, etc. The thermal stress generated in the friction process is small, the coating is not prone to a serious fracture, and wear performance is superior; this reduces the deficiency of ceramic coating to a certain extent.
Preparation of chromium oxide
① Reduction method: It is made by mixing sodium dichromate (or potassium dichromate) with sulfur, reducing and melting. The Cr2O3 produced by this method has a gray tone in the green, although the cost is low, the process is complex, and the environmental pollution is serious
② Thermal decomposition method decomposes by heating dichromatic anhydride or chromic anhydride. This method's quality of chrome green is heavily affected by fuel type and chromic anhydride conversion rate.
Price of chromium oxide
Chromium oxide particle size and purity will affect the product's price, and the purchase volume can also affect the cost of chromium oxide. A large amount of large amount will be lower. The price of chromium oxide can be found on our company's official website.
Chromium oxide supplier
Luoyang Tongrun Nano Technology Co. Ltd. (TRUNNANO) Luoyang City, Henan Province, China, is a reliable and high-quality global chemical material supplier and manufacturer. It has more than 12 years of experience providing ultra-high quality chemicals and nanotechnology materials, including chromium oxide, nitride powder, graphite powder, sulfide powder, and 3D printing powder. If you are looking for high-quality and cost-effective chromium oxide, you are welcome to contact us or inquire at any time.
The molecular formula of chromium oxide is Cr203 oxide, with a molecular weight of 152, dark grass green crystalline powder, a relative density of 5.21, a melting point of 1990 ℃, insoluble in water, slightly soluble in acid, and magnetic. Common chromium compounds include yellow-green crystal potassium dichromate K2Cr207 with a relative density of 2.7, yellow crystal potassium chromate K2Cr04 with a relative density of 2.5, yellow crystal sodium chromate Na2CrO4 · 10H2O, yellow crystal lead chromate PbCr04. The above chromium salts are decomposed into Cr203 under a reducing atmosphere; It is the colored oxide of green glass; Under the condition of strong oxidation, the amount of high-valent chromium CrO3 is more, which makes the glass yellow and green; In a strong alkaline glass (such as high lead glass), the glass is colored yellow mainly by Cr03. Cr203 and CuO share an area of pure green. In producing bottles and jars, cheap chromium slag (the residue after chromite production) is often used. In the production of ceramics, it is suitable for manufacturing green glaze, red glaze (adding basic lead chromate 2PbO · PbCr04), gray glaze (adding ZnO), and yellow sleeve (adding TiO2). It is the raw material for manufacturing green color cement.
Use of chromium oxide
Chromium oxide is widely used as ceramic coatings and refractories because of its stable crystal shape and high melting point. Ceramic coatings have excellent wear resistance, corrosion resistance, and heat resistance. Generally speaking, there are certain differences in physical and chemical properties between ceramic coatings and metal substrates, Especially the difference in linear expansion coefficient between the two. This difference causes sudden changes in the structure and performance of the interface between the coating and the substrate, resulting in large residual stress and thermal stress in the coating, which will cause the coating to fall off. C203 coating has the characteristics of high thermal conductivity, low coefficient of thermal expansion, etc. The thermal stress generated in the friction process is small, the coating is not prone to a serious fracture, and wear performance is superior; this reduces the deficiency of ceramic coating to a certain extent.
Preparation of chromium oxide
① Reduction method: It is made by mixing sodium dichromate (or potassium dichromate) with sulfur, reducing and melting. The Cr2O3 produced by this method has a gray tone in the green, although the cost is low, the process is complex, and the environmental pollution is serious
② Thermal decomposition method decomposes by heating dichromatic anhydride or chromic anhydride. This method's quality of chrome green is heavily affected by fuel type and chromic anhydride conversion rate.
Price of chromium oxide
Chromium oxide particle size and purity will affect the product's price, and the purchase volume can also affect the cost of chromium oxide. A large amount of large amount will be lower. The price of chromium oxide can be found on our company's official website.
Chromium oxide supplier
Luoyang Tongrun Nano Technology Co. Ltd. (TRUNNANO) Luoyang City, Henan Province, China, is a reliable and high-quality global chemical material supplier and manufacturer. It has more than 12 years of experience providing ultra-high quality chemicals and nanotechnology materials, including chromium oxide, nitride powder, graphite powder, sulfide powder, and 3D printing powder. If you are looking for high-quality and cost-effective chromium oxide, you are welcome to contact us or inquire at any time.
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