METHOD OF PROCESSING OF SPHENE CONCENTRATE Russian patent published in 2002 - IPC

FIELD: chemical technology of inorganic materials, more particularly manufacture of paper, plastic materials and paintwork materials. SUBSTANCE: concentrate is decomposed with sulfuric acid solution having concentration of 500-650 g/l of H₂SO₄ under boiling conditions till concentrate is decomposed to 70-80% with respect to TiO₂. Solid calcium-silicate residue is separated by filtration. Silicon-containing solution in amount of 20-40% SiO₂ with respect of TiO₂ in solution is introduced into titanium-containing solution. Titanium-containing product in pigment composition form is isolated by thermohydrolysis. Solid residue is treated with aluminium phosphate in amount of 1-5% Al₂O₃ with respect to weight of residue to prepare calcium-silicate pigment filler. Silicon-containing solution is filtrate resulting from decomposition of sulfuric with sulfuric acid having concentration of 200-250 g/l of H₂SO₄ at S:L ratio of 1:5. The resulting products have high paint and technical characteristics which are useful paintwork materials used for various purposes. EFFECT: increased recovery of titanium from sphene concentrate into final products up to 98% and greater safety of process due to lowering sulfuric acid concentration by 2 times due decomposition temperature by 20-40 C. 2 cl, 3 ex