Production method for low-iron low-silicon fire-resistant material grade chromium oxide green

Abstract

The invention discloses a production method for low-iron low-silicon fire-resistant material grade chromium oxide green. The production method comprises the following steps: (1), selecting premium-grade chromic anhydride, wherein the silicon content and the iron content are less than 0.02%; (2), adding the chromic anhydride in a rotary kiln, wherein the kiln head sealing cover of the rotary kiln adopts a stainless steel sealing cover, the kiln head refractory bricks are made of zirconia refractory, and the kiln tail is made of normal refractory material; (3), heating the rotary kiln, controlling the temperature of the kiln head to 1000-1200 DEG C, controlling the temperature of the kiln tail to 400-600 DEG C, and enabling the material to stay for 2-4 h in the rotary kiln; (4), after roasting, performing natural cooling to the room temperature, mixing material, screening, grinding and packaging, so as to obtain the low-iron low-silicon fire-resistant material grade chromium oxide green. According to the invention, through improvement and process optimizing control, the content of the silicon and iron meets the requirements of the fire-resistant material grade chromium oxide green, the product meeting the requirements of customers are produced, the product market is expanded, and the additional value of the low-iron low-silicon fire-resistant material grade chromium oxide green is increased.

Description

technical field [0001] The invention relates to the technical field of chromium salts, in particular to a production method of low-iron and low-silicon refractory grade chromium oxide green. Background technique [0002] Chromium oxide green is light green to dark green fine hexagonal crystals. It turns brown when hot, and turns green when cold. The crystal is extremely hard and stable, even if it is fed with hydrogen under red heat, it will not change. The melting point is about 2435°C and the boiling point is 4000°C. The Mohs hardness is 8.5, second only to diamond and corundum. It is mainly used as a pigment to produce refractory materials such as high chrome bricks and chrome corundum bricks, and to smelt metal chromium and chromium carbide. It is also used as a coloring agent for enamel, ceramics, artificial leather, building materials, a catalyst for organic chemical synthesis, light-resistant coatings, abrasive materials, green polishing paste and special ink for p...

AI Technical Summary

Problems solved by technology

Due to the high temperature in the roasting process of the traditional chromic anhydride thermal decomposition process, the kiln head and refractory bricks are made of ordinary carbon steel and ordinary refractory bricks. Therefore, due to factors such as high temperature and oxidation during the production process, the product It is very easy to mix impurities such as silicon and iron, which will affect the performance of the product