US 6,309,531 B1 · Process for extracting copper or iron

Abstract

A chemical process is disclosed for extracting copper or iron (M). The copper or iron is exposed to a leaching solution comprised of a metal salt (m) such that the copper or iron (M) is solvated and the metal ion (m) is reduced according to the reaction 2m+3(aq)+M(s)→2m+2(aq)+M+2(aq). An electrolytic cell has an anion exchange membrane separating an anode chamber from a cathode chamber. The leaching solution with the solvated copper or iron is placed into the cathode chamber of the electrolytic cell. A second solution comprising a reduced state metal salt m+2 of the salt in the leaching solution is then added to the electrolytic cell anode chamber. A voltage is applied to reduce and deposit the copper Cu+2 or iron Fe+2 at the cathode and to oxidize the metal m+2 at the anode. The oxidized metal m+2 in the anode chamber is then recycled as leaching solution for solvating copper or iron. The cathode chamber reduced-metal-containing solution is transferred to the anode chamber for oxidation of the reduced metal m+2.

Claims26

Dependent claims

A chemical process for extracting copper or iron from a metallic substrate comprising:

a. exposing the copper or iron (M) containing substrate to a leaching solution comprising a metal salt (m) wherein the substrate is insolvable in the metal salt solution, such that the copper or iron is solvated from the substrate and the metal ion is reduced according to the reaction
2m+3(aq)+M(s)→2m+2(aq)+M+2(aq);
b. providing an electrolytic cell with an anion exchange membrane that separates the anode from the cathode, thereby creating an anode chamber and a cathode chamber;
c. transferring the leaching solution with the solvated copper or iron into the cathode chamber of the electrolytic cell;
d. adding a second solution to the anode chamber, wherein the second solution comprises a reduced state metal salt m+2 of the salt in the leaching solution;
e. applying a voltage to the cell wherein the copper or iron is reduced and is removed from the metallic substrate leaving the metallic substrate substantially unaltered and is deposited at the cathode and the reduced metal m+2 is oxidized at the at the anode;
f. recycling the oxidized metal m+3 in the anode chamber to step (a) in order to solvate further amounts of copper or iron;
and
g. transferring the cathode chamber reduced-metal-containing solution to the anode chamber as the second solution of step (d).

6 more elements

A chemical process for extracting copper from a stainless steel substrate comprising:

a. exposing the copper-containing, stainless steel substrate to a leaching solution comprising a metal salt wherein the stainless steel substrate is insolvable in the leaching solution, such that the copper is solvated and the metal ion is reduced according to the following reaction
2m+3(aq)+Cu(s)→2m+2+Cu+2(aq);
b. providing an electrolytic cell with an anion exchange membrane that separates the anode from the cathode, thereby creating an anode chamber and a cathode chamber;
c. transferring the leaching solution with the solvated copper into the cathode chamber of the electrolytic cell;
d. adding a second solution to the anode chamber, wherein the second solution comprises a reduced state metal salt m+2 of the salt in the leaching solution;
e. applying a voltage to the cell wherein the copper is reduced and is removed from the stainless steel substrate leaving the stainless steel substrate substantially unaltered and is deposited at the cathode and the reduced metal m+2 is oxidized at the at the anode;
f. recycling the oxidized metal m+3 in the anode chamber to step (a) in order to solvate further amounts of copper;
and
g. transferring the cathode chamber reduced-metal-containing solution to the anode chamber of step (d).

6 more elements

Dependencies are inferred from the claim text.

Process for extracting copper or iron

Life of this patent

Process for extracting copper or iron

Life of this patent

Abstract

Claims26