Back to results
US 4,053,552 AGranted
Solvent extraction of zinc from sulfite-bisulfite solution
AssigneesGeneral Mills Chemicals, Inc., Mineral & Chemical Resource Co.
InventorsJay B. Clitheroe, Robert Brantley Sudderth
Life of this patent
Estimating the term…
Abstract
Zinc values are leached or converted in a solution containing excess SO.sub.2 or HSO.sub.3.sup.- ions, selectively extracted from that solution into an organic phase containing organo acid phosphates and stripped from the organic phase for further processing.
Claims8
In a process for hydrometallurgical purification of zinc, the steps consisting essentially of:
- forming an aqueous feed solution containing zinc values and a concentration of available bisulfite ions stoichiometrically in excess of the concentration of all metal values in said feed solution;
- contacting said aqueous feed solution with an organic phase containing an ion exchange reagent selected from the group consisting of organo acid phosphates at a pH of from about 4.5 to about 1.5, whereby the pH of said contacting step is maintained throughout extraction within said pH range and at least a portion of said zinc values are extracted into said organic phase;
- and, contacting said organic phase with an inorganic mineral acid strip solution, thereby stripping said zinc values from said organic stage into said strip solution.
In a process of hydrometallurgical recovery of zinc, the steps consisting essentially of:
- removing substantially all sulfate ions from an aqueous feed solution containing leached zinc values by adding to said solution calcium ions in an amount stoichiometrically in excess of the concentration of said sulfate ions and sulfur dioxide in an amount stoichiometrically in excess of the total metal cation concentration in said solution;
- contacting said feed solution with an organic phase containing an ion exchange material selected from the group consisting of organo acid phosphates at a pH of from about 4.5 to about 1.5, whereby the pH of said contacting step is maintained throughout extraction within said pH range and at least a portion of said zinc values are extracted into said organic phase;
Dependencies are inferred from the claim text.