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US 5,582,737 AGranted
Ion exchange and regeneration process for separation and removal of iron (III) ions from aqueous sulfuric acid metal ion-containing solutions
AssigneeEichrom Industries, Inc.
InventorsMichael J. Gula, David B. Dreisinger, E. Philip Horwitz
Life of this patent
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Abstract
An ion exchange separation, recovery and regeneration process for the control of iron has been developed to replace the conventional bleed stream process used in copper electrowinning. The process minimizes the loss of cobalt from the electrowinning circuit and strips the iron into a sulfate-based solution suitable for leach solution makeup. In addition, this process can effect a lowering of the total iron concentration in the electrolyte circuit with an associated increase in current efficiency.
Claims20
An ion exchange and regeneration process for the separation and removal of iron(III) ions from an aqueous sulfuric acid metal ion-containing solution that comprises the steps of:
- (a) contacting an aqueous sulfuric acid metal ion-containing solution that contains iron(III) ions as well as ions having a valence of less than +3 of at least one additional metal with solid ion exchange particles that bind to said iron(III) ions in preference to the additional metal ions present to form a solid/liquid phase admixture, said ion exchange particles comprising insoluble cross-linked copolymer particles having a plurality of pendent geminal diphosphonate groups of the formula --CH(PO.sub.3 R.sub.2).sub.2 or >C(PO.sub.3 R.sub.2).sub.2, wherein R is a mono- or divalent cation;
- (b) maintaining said contact with a sufficient amount of said solid ion exchange particles for a time period sufficient to form solid phase-bound iron(III) ions and an aqueous liquid phase containing sulfuric acid and said additional metal ions;
- (c) separating the solid and liquid phases;
- (d) contacting said separated solid phase-bound iron(III) ions with an aqueous reducing solution containing 0.5 to about 6 molar sulfuric acid, at least a catalytic amount of copper ions and an amount of sulfurous acid sufficient to reduce said solid phase-bound iron(III) ions to iron(II) ions to form a second solid/liquid phase admixture;
- (e) maintaining said second solid/liquid phase admixture at a temperature of about 65.degree. C. to about 85.degree. C. for a time period sufficient to form an aqueous sulfuric acid liquid phase containing iron(II) ions and regenerated solid phase ion exchange particles;
- and
- (f) separating the iron(II)-containing liquid phase from the regenerated solid phase ion exchange particles.
4 more elements
An ion exchange and regeneration process for the separation and removal of iron(III) ions from an aqueous sulfuric acid metal ion-containing solution that comprises the steps of:
- (a) contacting an aqueous sulfuric acid metal ion-containing solution that contains about 1 to about 3 molar sulfuric acid, iron(III) ions and additional metal ions selected from the group consisting of iron(II), manganese(II), copper(II) and cobalt(II) with solid ion exchange particles that bind to said iron(III) ions in preference to said additional metal ions to form a solid/liquid phase admixture, said ion exchange particles comprising insoluble cross-linked copolymer particles having a plurality of pendent geminal diphosphonate groups of the formula --CH(PO.sub.3 R.sub.2).sub.2 or >C(PO.sub.3 R.sub.2).sub.2, wherein R is a mono- or divalent cation;
- (b) maintaining said contact with a sufficient amount of said solid ion exchange particles for a time period sufficient to form solid phase-bound iron(III) ions and an aqueous liquid phase containing sulfuric acid and said additional metal ions;
- (c) separating the solid and liquid phases;
- (d) contacting said separated solid phase-bound iron(III) ions with an aqueous reducing solution containing 0.5 to about 6 molar sulfuric acid, at least a catalytic amount of copper ions and sulfurous acid at a concentration of about 0.3 to about 1.0 molar as SO.sub.2 to reduce the bound iron(III) ions to iron(II) ions and form a second solid/liquid phase admixture;
- (e) maintaining said second solid/liquid phase admixture at a temperature of about 65.degree. C. to about 85.degree. C. for a time period sufficient to form an aqueous sulfuric acid liquid phase containing iron(II) ions and regenerated solid phase ion exchange particles;
- and
- (f) separating the iron(II)-containing liquid phase from the regenerated solid phase ion exchange particles.
4 more elements
An ion exchange and regeneration process for the separation and removal of iron(III) ions from an aqueous sulfuric acid metal ion-containing solution that comprises the steps of:
- (a) contacting solid phase ion exchange particles contained in a column with an aqueous sulfuric acid di- and trivalent metal ion-containing solution to form a solid/liquid phase admixture,
- said aqueous sulfuric acid di- and trivalent metal ion-containing solution containing (i) about 1 to about 3 molar sulfuric acid, (ii) about 1 to about 10 grams/liter iron as iron(III) ions or as a mixture of iron(II) and iron(III) ions, (iii) about 30 to about 50 grams/liter copper(II) ions and (iv) about 0.05 to about 0.2 grams/liter cobalt(II) ions,
- said solid phase ion exchange particles binding to said iron(III) ions in preference to the other enumerated ions, and comprising insoluble cross-linked copolymer particles having a plurality of pendent geminal diphosphonate groups of the formula --CH(PO.sub.3 R.sub.2).sub.2 or >C(PO.sub.3 R.sub.2).sub.2, wherein R is a mono- or divalent cation;
- (b) maintaining said contact with a sufficient amount of said solid ion exchange particles for a time period sufficient to form solid phase-bound iron(III) ions and an aqueous liquid phase containing sulfuric acid and said divalent metal ions;
- (c) elutingly separating the solid and liquid phases;
- (d) contacting the column-contained solid phase-bound iron(III) ions with an aqueous reducing solution containing about 1 to about 3 molar sulfuric acid, copper ions present at about 0.5 to about 7 grams/liter and sulfurous acid present at a concentration of about 0.6 to about 0.8 molar as SO.sub.2 to reduce the bound iron(III) ions to iron(II) ions and a form second solid/liquid phase admixture;
- (e) maintaining said second solid/liquid phase admixture of about 65.degree. C. to about 75.degree. C. for a time period sufficient to form an aqueous sulfuric acid liquid phase containing iron(II) ions and a solid phase containing at least 50 percent regenerated solid phase ion exchange particles;
- and
- (f) elutingly separating the iron(II)containing liquid phase from the regenerated solid phase ion exchange particles.
6 more elements
Dependencies are inferred from the claim text.