CYCLIC PREPARATION METHOD FOR PRODUCING TITANIUM BORIDE FROM INTERMEDIATE FEEDSTOCK SODIUM-BASED TITANIUM-BORON-FLUORINE SALT MIXTURE AND PRODUCING SODIUM CRYOLITE AS BYPRODUCT

摘要

The invention discloses a cyclic preparation method for producing titanium boride from intermediate feedstock sodium-based titanium-boron-fluorine salt mixture and producing sodium cryolite as byproduct, which comprises the steps: a) boric acid or boric anhydride is added with hydrofluoric acid and then with sodium carbonate solution for concentration and crystallization to generate sodium fluoborate; titanium-iron concentrate is added with hydrofluoric acid and then with sodium carbonate and sodium hydroxide to obtain sodium fluotitanate; B) the sodium fluoborate is mixed with the sodium fluotitanate, and the mixture reacts with aluminum to generate titanium boride and sodium cryolite; C) the sodium cryolite is sucked out and then fed into a rotary reaction kettle together with concentrated sulfuric acid, hydrogen fluoride gas as well as sodium sulfate and sodium aluminum sulfate are generated by reaction in the rotary reaction kettle, and the hydrogen fluoride gas is collected and then dissolved in water to obtain hydrofluoric acid aqueous solution; and D) the obtained hydrofluoric acid aqueous solution is recycled. The invention can achieve the recycling of the byproduct sodium cryolite, simplify the process flow in the preparation of titanium boride, lower the process condition and comprehensive production cost in the preparation of titanium boride, improve the production efficiency and reduce the pollution to environment.