Chromium Oxide Green is a kind of dense, completely opaque, medium purity light green pigment. A furnace product, chrome oxide green is absolutely durable in terms of the use and condition of all pigments, including the highest temperature conditions. Compared with emerald green and phthalocyanine green, chrome oxide green has inactive color effect, low coloring power and difficult color mixing; therefore, despite its pleasant tone, chrome oxide green is rarely used by artists. Chrome oxide green was discovered by French vauquelin (1797), and became a kind of ceramic pigment in the early 19th century. It first became a painting pigment around 1840 and was widely used in 1862.
Character of chrome oxide green
Bright green to dark green. Density: 5.21. Melting point: 2266 degrees. Boiling point: 4000 degrees. It has metallic luster, magnetism, strong covering power, high temperature resistance, sunlight resistance, insoluble in water, difficult to dissolve in ACID, relatively stable in the atmosphere, has no influence on the general concentration of acid and alkali and sulfur dioxide gas, has excellent outstanding pigment quality and fastness.
Application of chrome oxide green
The color of chrome oxide green is bright green to dark green, density: 5.21. Melting point: 2266 degrees. Boiling point: 4000 degrees. It has metallic luster, magnetism, strong covering power, high temperature resistance, sunlight resistance, insoluble in water, difficult to dissolve in acid, relatively stable in the atmosphere, has no influence on the general concentration of acid and alkali and sulfur dioxide gas, has excellent outstanding pigment quality and fastness.
It is used for smelting metal chromium and chromium carbide, coloring enamel, ceramics, glass, artificial leather, refractories, building materials coloring, organic synthesis catalyst, special ink for manufacturing Sun resistant materials and printing paper money, metal polishing and grinding materials, Chromizing on metal surface, magnetic materials, etc. Used in coatings, ceramics, rubber, art pigments, and camouflage coatings.
The raw material of chrome oxide green is chromic acid, sodium dichromate (or potassium) and sulfur, etc., which are calcined at high temperature or decomposed by ammonium dichromate.
You can get help from the pictures of chrome oxide green. After all, through the color of the picture, you can compare the purity of chrome oxide green, and you can see what the main functions of chrome oxide green are. Finally, the sense of quality that can be brought will be more prominent, and the benefits will be very different. The advantages that can be brought will be extremely obvious.
The quality of various types of chrome oxide green is different, and the content of chrome oxide green will be different in the process of use, so it is more important to better grasp the advantages and disadvantages of iron manufacturers. There are many types of chrome oxide green, including natural and synthetic types, so the specific selection still needs to be determined according to the actual situation.
Moreover, chrome oxide green is mainly used as a pigment, which can be used as colorant in various rubber, plastic, construction, paint and other industries. In the use of iron red is the use of strong coloring ability, covering power and stable chemical properties, so the reliability will be significantly improved.
Nowadays, pigments are no longer only suitable for drawing and painting, but also widely used in many industries. For example, outdoor cultural wall setting, building coloring, and ceramic product drawing and so on. With the expansion of the application space of pigments, the requirements for other properties of pigments are also gradually improved. For example, it can resist light irradiation, air oxidation, acid rain corrosion, organic solvents and so on. At this time, adding chrome oxide green to the pigment can solve all problems at once, which is why chrome oxide green can be used as pigment auxiliary material.
The amount of chrome oxide green used in ceramic industry is amazing. According to incomplete statistics, the amount of chrome oxide green used in ceramics and related supporting enterprises is about 200000-300000 tons per year. Basically, as long as ceramic enterprises use chrome oxide green directly or indirectly.
In particular, among the chemical materials required by pigment manufacturers matching ceramic enterprises, chrome oxide green accounts for a considerable proportion, and the market price of chrome oxide green has gradually increased in recent two years, from about 20000 yuan / ton in 2008 to about 40000 yuan / ton at present.
In addition to the increase of labor costs such as raw materials, another very important reason is that the state began to carry out environmental rectification on chromium oxide green enterprises since several years ago, especially the serious chromium slag pollution incident in Henan Province last year, which further aroused the social concern for the environmental protection of chromium salt production enterprises.
Preparation of chrome oxide green
Chromic acid, sodium dichromate (or potassium) and sulfur are roasted at high temperature. Or from the thermal decomposition of ammonium dichromate.
It is resistant to high temperature, light and various chemicals. The reflection of pure products to infrared ray is close to natural chlorophyll.
CAS No.: 1308-38-9
Chromium oxide green, also known as chromium trioxide and chromium oxide, has a molecular weight of 151.99. It is hexagonal, green powder. The density is 5.21 g / cm3, Mohs hardness is 8.5 ~ 9, which is close to corundum (Al2O3), second only to diamond, but higher than quartz SiO2, topaz al2 [SiO4] (F, oh) 2 and zircon ZrSiO4). The refractive index is 2.5 (good covering index), and the specific heat capacity (20 ℃) / 0.17j / (g · K). It is 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 mixed sulfuric acid. It is very stable to light, atmosphere and corrosive gases (H2S, SO2, etc.) and has excellent weather resistance. It is stable when heated. The melting point is 2265 ℃ and the boiling point is 4000 ℃. Chromium trioxide is mainly used in metallurgy, pigment, grinding and polishing, refractories and newly developed melt blown coatings.
