CONICET | Buscador de Institutos y Recursos Humanos

Boric acid, which has multiple and varied applications (pharmacy, ceramics, etc.) is obtained from the reaction of some borate with sulphuric acid. This industry generates liquid effluents (mother liquors) which contains boric acid, sodium sulphate, and sodium chloride. Recovering sodium sulphate allows the mother liquor recycling minimizing the liquid discharge. A novel and clean process is proposed to recover the sodium sulphate present in the mother liquors by the salting-out procedure, using methanol and ethanol as salting-out agents. The influence of boric acid concentration on the recovery of sodium suphate has been considered. The results show that a selective recovery of sodium sulphate from the treated liquor is possible and it is over the 98 % when the alcohol proportion is about the 70%, for both methanol and ethanol. Sodium sulphate recovery increases when the boric acid concentration diminishes.