| 摘要 |
FIELD: chemistry.SUBSTANCE: invention relates to chemistry and can be used for production of pigment for construction materials, plastic, paint and lacquer, glass and ceramics. Sodium monochromate reacts with ammonia gas at temperature of 200-800 °C. Hydrolysis of reaction product is carried out. Water pH is reduced before hydrolysis or pH of alkaline mother liquor is reduced during or after hydrolysis to 4-11 by adding carbon dioxide. Precipitated hydrolysis product is separated at pH = 4-11. Hydrolysis product is calcined at 700-1,400 °C.EFFECT: invention enables production of chromium (III) oxide, containing very small amount of sulphur and alkali metals and by-products.12 cl, 3 ex |
