PURIFICATION OF BORIC ACID IN THE ION EXCHANGE PROCESS Russian patent published in 2021 - IPC C01B35/10 B01D9/00 

FIELD: chemistry.

SUBSTANCE: present invention relates to a method for purification of boric acid by the ion exchange method. Boric acid is dissolved in hot demineralised water. The hot solution is filtered under pressure. The hot saturated solution purified from water-insoluble impurities is passed through a column containing a strong cation exchange resin, followed by passing through a column containing a weak anion exchange resin at the same temperature, and then cooled. The crystals settled due to the cooling are separated from the mother liquid, reducing the amount of aqueous solution therein, and then dried. The waste solution formed during crystallisation and the filtrate formed after separating the crystals from the aqueous solution are mixed and used in the process of dissolving boric acid.

EFFECT: developed method provides a possibility of reducing the impurities of sodium, sulphate, chloride and iron in technical boric acid down to less than 1 pt./mil, and is more cost-effective and environmentally sustainable compared to the existing methods.

15 cl, 2 tbl, 1 ex, 1 dwg