| 摘要 |
METHOD FOR TREATING SOLUTIONS IN HYDROMETALLURGICAL ZINC PROCESSING Dilute aqueous sulfate solutions encountered in hydrometallurgical treatment of zinc-containing materials are treated for the control of bulk and for the recovery of metal values. The solutions are treated by electrodialysis for the recovery of a solution depleted in zinc, usually containing less than about 1 g/L zinc, and other ions for return to the hydrometallurgical treatment, and for the recovery of a solution concentrated in zinc, usually containing about 70 to 160 g/L zinc, for return to the hydrometallurgical treatment and the recovery of contained values. To control the ion concentrations in the concentrate circulating through the concentrate compartments of the electrodialysis unit, a solution such as water, diluate sulfuric acid, a portion of the feed solution or a portion of the circulating diluate may be added to the circulating concentrate. Electrodialysis is carried out under turbulent conditions at linear flow velocities from about 3 to 7 cm/s, at about 10 to 500 A/m2, preferably at about 100 to 400 A/m2, and at pH values below about 5.2, preferably in the range of about 3 to 5.
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