FIELD: industrial inorganic synthesis. SUBSTANCE: invention relates to technologies involving sulfuric acid processing of products containing titanium compounds to produce titanium dioxide pigments, titanium tanners, or metallurgical titanium dioxide. Method consists in decomposing heterogeneous mixture of titanium carbonitride and silicon carbide by sulfuric acid at heating and with addition of nitric acid to give titanium-containing solution, which is filtered for subsequent isolation of desired product using known procedures. Nitric acid is added with velocity 0.018-0.020 t of acid per 1 t of titanium dioxide in 1 min, while simultaneously feeding oxygen with velocity 3.55-3.95 cu. m of O2 per 1 t of titanium dioxide in 1 min. EFFECT: twice reduced nitric acid intake, eliminated injurious emissions, and regenerated up to 70-75% of nitric acid.
