Chromium oxide is a basic inorganic chemical raw material. Its chemical name is chromium trioxide, Cr2O3. It belongs to the trigonal crystal system. If a hexagonal unit cell is taken, the unit cell parameters are 4.960x 4.960×13.584 and the axial ratio is 4.473. Cr2O3 has a γ-Al2O3 structure. This rigid crystal is composed of oxygen ions that are closely packed and M3+ ions fill the octahedral gaps formed by these close packings.
It is known that the ionic radii of Cr3+ and O2- are 0.069nm and 0.132nm respectively, and the ratio of positive and negative ionic radii is 0.52, in the range of 0.414~0.732. Therefore, the coordination number of Cr3+ is 6, so it is in the octahedral gap. One chromium ion Surrounded by 6 oxygen ions in the crystal structure of Cr2O3, the oxygen ions occupy the lattice positions of the hexagonal close-packed crystal, and the chromium ions are located in the octahedral gaps of the hexagonal close-packed structure, which is the same as the hexagonal close-packed and face-centered cubic crystals. On average, each array point can have one octahedral gap and two tetrahedral gaps, so the close-packed hexagonal structure contains a total of 6 octahedral gaps. In order to maintain electrical neutrality, there are only 2 Cr3+ to 3 O2-. Therefore, the octahedron Only 2/3 of the octahedral voids are filled.
As an important chemical raw material, chromium oxide green is widely used in metallurgy, ceramic pigments, leather grinding and polishing and many other industrial productions. Especially in the ceramic pigment industry, chromium oxide is widely used in most ceramic pigments as a major color development and auxiliary color additive. The market price of chromium oxide green has also been on the rise since 2008, rising from about 20,000 yuan/ton before to about 40,000 yuan/ton currently.
Chromium Sesquioxide Uses
Chromium trioxide is often used to make pigments for green paints, ceramics, etc., and can also be used as a catalyst for organic synthesis (such as the production of polyethylene and butadiene).
Chromium oxide green is mainly used for smelting metallic chromium. It can also be used as a pigment in paints and ceramics, a catalyst for organic synthesis, and is also used to make abrasive materials, green polishing pastes and inks.
As a green pigment, chromium oxide green can be used in printing inks and coatings. In addition, it is widely used as a colorant in glass, ceramic tiles, ceramic vessels, etc. It can also be used as a greasy abrasive material such as green oil, in chrome plating and plating. Nickel is used for grinding base plates and surface polishing. The powder itself can be used as a fine grinding material in the manufacture of metal and glass products. It can also be made into chromium-magnesium or magnesium-chromium refractory bricks, and can be used as raw material for metallic chromium.