| 摘要 |
chemical industry. SUBSTANCE: method involves addition of 1300 ml of H2SO4 and (NH4)2SO4 taken in the amount of 0.2-0.5% of concentrate mass to 1 kg of sphene concentrate. Mixture is heated to 80-90 C and in 2 h heated concentrated H2SO4 is added. Mixture is kept, cooled, precipitate (sulfate cake) is repulped in H2SO4 solution, filtered off and added to iron-free water. Suspension is heated to boiling point at the rate 10-20 degrees/h at stirring. Precipitate of titanium hydroxide applied on CaSO4 and SiO2 is separated, washed out and subjected for salt treatment. Salt treatment is carried out with modifying suspension. Suspension is obtained from liquid phase after thermal treatment where apatite and then nepheline are added to residual content of P2O5 in mixture 1-4 wt.- %. Suspension is taken on the basis of T : Vc = 1 : (1.0-1.5). Salt treatment is carried out at stirring and then ammonia is added to pH = 4.5. Precipitate is filtered off and calcined. Extraction of TiO2 is 92-95%, content of water-soluble impurities is 0.92-2%, brightening ability is 400-450 conventional units. Invention can be used in producing pigments in leather, paint and varnish industry and in paper production. EFFECT: improved method of processing. 3 ex |
