| 摘要 |
<p>There is provided a method for treating zinc-containing sulfate solutions which comprises an acid removal for the recovery of a substantially pure sulfuric acid solution and a solution low in acid and containing the zinc and metal impurities from the sulfate solution. The acid removal is carried out by a membrane process that consists of dialysis, electrodialysis or dialysis integrated with electrodialysis. The dialyzate or diluate is subjected to a dual-circuit, side-by-side, simultaneous solvent extraction of zinc and sulfuric acid. In one circuit sulfuric acid is extracted from the dialyzate or diluate and the raffinate from the zinc extraction with an aminecontaining extractant. Acid is stripped from the loaded organic with water or an alkaline substance, and is recovered as sulfuric acid or as a sulfate, preferably as ammonium sulfate. In the other circuit, zinc is extracted from the raffinate from the acid extraction with an organic phosphoric-, phosphinic-, phosphonic- or thiophosphinic acid-containing extractant. The zinc is stripped from the loaded organic with acid, and is recovered as a concentrated zinc sulfate solution. A residual solution substantially containing the impurities is removed from the process. The extraction and stripping may be carried out in one or more stages.</p> |
