Chrome Oxide Green

1. Chromium oxide green, also known as chromium trioxide and chromium oxide, is a hexagonal crystal system, green powder. Its molecular weight is 151.99, its density is 5.21g/cm3; its Mohs hardness is 8.5~9, which is close to corundum (Al2O3), but exceeds quartz (SiO2) and topaz (Al2(SiO4)(OH)2); its refractive index is 2.5 ( Covering rate is good), specific heat capacity (20 ℃) is 0.17J/(g K); insoluble in water, acid and organic solvents, slightly soluble in concentrated sodium hydroxide solution, soluble in hot sodium bromate solution, hot concentrated Perchloric acid solution or boiling sulfur-phosphorus mixed acid

2. It is extremely stable to light, atmosphere and corrosive gases (H2S, SO2, etc.), and has excellent weather resistance; chrome oxide green is thermally stable, with a melting point of 2265 °C and a boiling point of 3000 °C, and is a high-quality refractory material. The common chromium oxide green in the market presents bright green to dark green, with metallic luster; it has the characteristics of magnetism, strong covering power, high temperature resistance, sun resistance, insoluble in water, insoluble in acid, etc. It is relatively stable in the atmosphere. The acid and alkali of general concentration and sulfur dioxide gas have no effect on it, and it has excellent and outstanding pigment quality and fastness.

3. Purpose

1). Lead chrome green is the main coloring pigment in the paint industry, and most of the green paints are formulated with this pigment. In addition, it is also used in paints and plastics. Its application range is very similar to that of lead chrome yellow. Due to the presence of chrome yellow in the composition, attention should be paid to the toxicity of lead. Lead chrome green contains iron blue and the oxidant lead chromate, so when the dust encounters sparks, there is a possibility of spontaneous combustion, so be careful when drying and crushing. After burning, the lead chrome green completely loses the characteristics of green pigment and turns into a dark brownish-yellow substance. In addition, when making nitro paint, the rolling process is not directly rolled with lead chrome green, but the process of grinding with lead chrome green to prevent burning during rolling.

2). Used in metallurgy, also used as ceramics, refractory materials, raw materials for pigment industry and organic synthesis catalysts, etc.

3). Used as analytical reagent, catalyst

4) Used as a coloring, wear-resistant and corrosion-resistant filler for adhesives and sealants. It can also be used as a colorant for enamel, ceramics, artificial leather, and building materials; a catalyst for organic chemical synthesis; a light-fast coating and a special ink for printing banknotes

5) Used as a colorant for cosmetics, mainly used in eye cosmetics, but not in oral and lip cosmetics, not recommended for facial cosmetics and nail polish

6) Chromium trioxide is one of the main components of the silver-plated layer dipping solution. The newly prepared chromium dioxide is an important raw material for preparing chromium fluoride and chromium bromide.