| 摘要 |
Alkali fluosilicates can be recovered from wet process phosphoric acid without contaminating the acid with additional anions, by reacting phosphoric acid with an alkali metal salt, such as sodium chloride, to form the corresponding alkali metal phosphate; extracting the mixture with an organic amine, to remove the contaminating anion; reacting the resultant phosphate solution with wet process phosphoric acid to precipitate an alkali metal fluosilicate, and separating the fluosilicate, thereby leaving residual phosphoric acid. Both the phosphoric acid and the fluosilicate are substantially free of contaminating anion. A portion of the treated phosphoric acid can be recycled for reaction with additional alkali metal salt. |
