| 摘要 |
chemical industry, more particularly preparation of pigments for paper, plastics and paint materials. SUBSTANCE: sphene is added to H2SO4 solution with concentration of 350-550 g/l. 5-10 h later phosphate solution containing 25-30% of P2O5 is added to suspension heated to boiling temperature. Amount of phosphate solution binds 20-35% of TiO2 in sphene phosphate. Phosphate solution is filtrate after sulfate stripping of apatite. During stirring operation TiO2 nucleus and TiO3 solution are added. The mixture is maintained during heating for 10 hours and diluted with hot water. Precipitate is separated, washed with water at S:L ratio of 1:(5-6), calcined at 650-750 C. Recovery of TiO2 is about 95%. Filtration rate of suspension is 500-600 l/sq.m. Oil absorption of pigment is 25.8-27.4 g/100 g; covering power is 49.7-51.0 g/sq. m; content of water soluble salts is 0.55-0.98%. EFFECT: more efficient processing method. 2 cl, 4 ex, 2 tbl |
