METHOD OF COMPLEX PROCESSING OF TITANIUM-CONTAINING MINERAL RAW MATERIALS Russian patent published in 2017 - IPC C22B3/06 C22B3/44 C01G23/47 C01G49/06 C09C1/24 C01F17/00 

FIELD: chemistry.

SUBSTANCE: when processing the original titanium-containing mineral raw material, it is moistened and mixed with ammonium hydrofluoride in a stoichiometric ratio. Then heated to a temperature of 108-130°C with stirring for 40-60 minutes. Then it is leached with a 15-18% solution of ammonium fluoride at a temperature of 70-75°C and T: L=1:100. The resulting insoluble precipitate of fluoromammonium iron salts is separated from the solution by filtration and washed with a 10% ammonium fluoride solution at a temperature of 70-75°C. Decantation is separated from the precipitate by heavier particles of unreacted starting mineral raw material. The solution obtained after filtration of the decantant containing ammonium fluorotitanate is combined with the solution filtered after leaching and subjected to post-purification from iron. The post-treatment is carried out by partial hydrolysis with a 25% solution of ammonia, which is gradually added to the filtrate to a pH of 6.5-7.5 at a temperature of about 75°C. Next, hydrolysis of the resulting solution is carried out by adding an ammonia solution to pH 9 with the precipitation of ammonium oxopentafluorotitanate, which is subjected to pyrohydrolysis to produce titanium dioxide. The precipitate of iron salts is treated with 15-20% hydrofluoric acid to produce a precipitate of calcium, magnesium and aluminium fluorides with small particles of the initial titanium-containing raw material and an acidic solution of the fluoromammonium iron salt. This solution is neutralized with a 25% ammonia solution to a pH of 4-5 with salting out ammonium fluorosulfate (NH₄)₃FeF₆ with purity of 99%. Ammonium fluoroferrate is filtered off and subjected to step pyrohydrolysis to 450-500°C to obtain a red iron oxide (III) of pigment quality. The unreacted mineral residue is sent for further processing to recover REE compounds.

EFFECT: invention makes it possible to increase the completeness and efficiency of processing ilmenite concentrate, expand the range of commercial products and reduce the amount of waste, while increasing the degree of purification of marketable products.

2 cl, 2 ex