Method of recycling hydrochloric and hydrofluoric acid effluent
AssigneeArkema France
InventorsPascal Dufour, Cyrille Le Toullec
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Abstract
A method of recycling mixtures of hydrochloric and hydrofluoric acid. In particular, a method of recycling hydrofluoric acid and boron fluoride mixtures. A process for upgrading mixtures of fluoroboron compounds contaminated with chlorides as an aqueous solution of boron fluoride hydrates, including a step of vacuum distillation. Also, a method of producing gaseous boron trifluoride.
Claims11
A process for upgrading mixtures of fluoroboron compounds contaminated with chlorides as an aqueous solution of boron fluoride hydrates, comprising a step of vacuum distillation.
A process for upgrading hydrochlorofluoric acid, comprising (i) at least one step during which at least one boron compound chosen from boric acid (H3BO3), metaboric acid (HBO2) and boric anhydride (B2O3) is placed in contact with an aqueous solution of hydrochlorofluoric acid to give a mixture of fluoroboron compounds and of hydrochloric acid;
- (ii) a distillation step to give, on the one hand, hydrochloric acid and, on an other hand, a mixture comprising water, residual hydrochloric acid and a mixture of fluoroboron compounds, and (iii) a step of vacuum distillation of the mixture obtained in step (ii) to remove the residual hydrochloric acid and the water so as thus to give a concentrated aqueous solution of boron trifluoride hydrates.
Dependencies are inferred from the claim text.