METHOD OF PRODUCTION OF BLACK THERMOSTABLE INORGANIC PIGMENTS Russian patent published in 2006 - IPC C09C1/24 C01G49/08 

FIELD: paint-and-varnish industry; construction engineering; painting plastics and leather; production of enamel paints, primers, putties, wall-paper and veneer.

SUBSTANCE: solution of hydraulic washing-out of used melt of titanium chlorates containing ferrous chloride (II) is treated with alkaline reagent to pH= 2.5-4.5 at precipitation of oxyhydrates of metals. Solution is separated from sediment by filtration. Cleaned solution thus obtained is mixed with solution obtained after leaching-out of copper-containing melt of process of cleaning titanium tetrachloride from vanadium compounds by means of copper powder. Ratio of volumes of said solutions is 1 : (0.5-2), respectively. Mixed solution is treated with alkaline reagent to pH= 9-11. Suspension thus obtained is subjected to filtering. Sediment is washed, dried and calcined additionally at temperature of 400-700°C. Proposed method makes it possible to utilize wastes of process of production of titanium dioxide from titanium tetrachloride. Pigment thus obtained has rich black color, reflection coefficient of 3.5±0.5%, hiding power of 4.5±0.5 g/m² and pH of aqueous suspension of 7.0±0.5.

EFFECT: enhanced efficiency.

2 cl, 1 ex