METHOD OF PREPARING VANADIUM OXIDE Russian patent published in 2015 - IPC C01G31/02 

FIELD: chemistry.

SUBSTANCE: method comprises the following steps: mixing vanadium slag with calcium oxide or limestone to form a mixed material; roasting the obtained mixed material to obtain a calcined clinker; leaching the calcined slag using an oxalate solution with $$C_2{O}_4^{2-}$$ ion concentration of 35-70 g/l at 80-90°C; separating the liquid and solid phases after the leaching reaction to obtain a vanadium-containing liquid leaching product and residual slag; performing treatment to remove silicon from the vanadium-containing liquid leaching product, as a result of which concentration of silicon in the vanadium-containing liquid leaching product becomes less than 0.1 g/l, and then adding ammonium oxalate to the vanadium-containing liquid leaching product to control the molar ratio of $$N{H}_4^{+}$$ to TV in the range of 2-3.5, as a result of which ammonium metavanadate is precipitated and filtered to obtain ammonium metavanadate and liquid wastes; oxidising the ammonium metavanadate, calcination and deamination with preparation of vanadium pentoxide or with further preparation of vancium trioxide via a reduction reaction.

EFFECT: use of vanadium slag with high calcium and phosphorus content, low reagent consumption and cost of the product.

10 cl, 3 ex