Method for cyclically preparing boron and coproducing sodium cryolite using sodium fluoborate as intermediate material

摘要

The disclosure discloses a method for cyclically preparing monomer boron and coproducing sodium cryolite using sodium fluoborate as an intermediate material, which includes the following steps: A) adding hydrofluoric acid to boric acid or boron oxide to enable a reaction to form fluoboric acid; B) adding a sodium carbonate aqueous solution to the fluoboric acid to enable a reaction to form the sodium fluoborate; C) putting the sodium fluoborate into a reactor, adding aluminium to react with the sodium fluoborate to form the monomer boron and sodium cryolite, or, putting the aluminium into the reactor, and adding the sodium fluoborate to react with the aluminium to form the monomer boron and sodium cryolite; D) extracting the sodium cryolite, sending the sodium cryolite to a rotary reaction kettle together with concentrated sulphuric acid to enable a reaction to form hydrogen fluoride gas and aluminium sodium sulphate, collecting the hydrogen fluoride gas and dissolving it into water to obtain the hydrofluoric acid; E) recycling the obtained hydrofluoric acid to Step A to leach the boric acid or boron oxide. The disclosure can recycle the coproduct sodium cryolite, thereby shortening the process of preparing monomer boron, reducing the comprehensive cost of production, improving the production efficiency and reducing environmental pollution.