Separation of boric acid from mixtures thereof with sulphuric acid
AssigneeSandoz Ltd.
InventorJosef Hakl
Life of this patent
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Abstract
The present invention relates to a process for the separation of boric acid from boric acid-containing sulphuric acid in which the concentration of the sulphuric acid is adjusted such that the boric acid precipitates therefrom.
Claims11
A process for the separation of boric acid from a boric acid-containing aqueous sulphuric acid mother liquor, the concentration of boric acid in said mother liquor being at least 2% by weight based on the H.sub.2 SO.sub.4, comprising adjusting the concentration of the sulphuric acid towards 50% by weight H.sub.2 SO.sub.4, based on H.sub.2 SO.sub.4 and H.sub.2 O, with the proviso that the final concentration lies within the range of from 49 to 51% by weight, and with the further proviso that where the initial sulphuric acid is dilute, the concentration thereof is adjusted towards 50% by weight by distilling off water, and then separating the boric acid which precipitates out of the mother liquor.
A process for the separation of boric acid from a boric acid-containing aqueous sulphuric acid mother liquor, the concentration of sulphuric acid in said mother liquor being greater than 50% by weight and the concentration of boric acid in said mother liquor being at least 2% by weight based on the H.sub.2 SO.sub.4, comprising adjusting the concentration of the sulphuric acid towards 50% by weight H.sub.2 SO.sub.4, based on H.sub.2 SO.sub.4 and H.sub.2 O, with the proviso that the final concentration lies within the range of from 45 to 55 by weight, and then separating the boric acid which precipitates out of the mother liquor.
Dependencies are inferred from the claim text.