METHOD FOR PRODUCTION OF INORGANIC PIGMENT BASED ON COMPLEX SULFIDE OF ALKALINE, ALKALI-EARTH AND RARE-EARTH METALS (VERSIONS) Russian patent published in 2009 - IPC C09C1/02 C01G1/12 

FIELD: technological processes, chemistry.

SUBSTANCE: invention may be used in paint and varnish industry, production of plastics, ceramics, construction materials. Method for production of inorganic pigment based on complex sulfide of alkaline, alkali-earth and rare earth metals includes mixing of initial charge components and its interaction with sulfur-containing agent during heating. Sulfur-containing agent used is gaseous products of ammonium rhodanate thermolysis, and charge treatment with products of ammonium rhodanate thermolysis is carried out at the temperature of 650-700 °C with further heating up to 900-1000 °C. In the other version of invention charge is mixed with sulfur-containing agent, such as sulfur, reducing agent is located above charge, and mixture is thermally treated, then prepared product is additionally treated with sulfur-containing agent, such as gaseous products of ammonium rhodanate thermolysis, at the temperature of 650-700 °C with further heating up to 900-1000 °C.

EFFECT: possibility to use less aggressive sulfidising agents, reduction of sulfidising time and simplification of process with preservation of produced pigments quality.

2 cl, 1 dwg, 5 ex