Direct leaching from sulfidic refractory ores or concentrates
AssigneesArizona Board of Arizona on Behalf of the University of Arizona, TCB International LLC
InventorsJaeheon LEE, Ken Jewell, David Drye
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Abstract
The present invention relates a method of leaching metals involving the use of thiourea, sodium metabisulfite (SMB), sulfuric acid, and a source of hypochlorite. The method is useful, for example, for leaching metal-containing materials to obtain precious metals (e.g., gold) as well as for purifying base metals (e.g., copper), and for removal of metals from electronic wastes.
Claims19
A method of leaching a material, comprising:
- a) mixing water and sulfuric acid to obtain an aqueous sulfuric acid solution;
- b) dissolving thiourea and sodium metabisulfite in an amount of the solution of step (a);
- c) adding the solution of step (b) to the remaining amount of sulfuric acid solution made in step (a);
- d) adding a source of hypochlorite to the solution made in step (c) to obtain a leaching solution;
- e) adding a material chosen from an ore, a metal-containing material, and a concentrate, to the solution of step (d) to start the leaching process;
- and
- f) recovering metal;
- wherein said thiourea in the solution of step (b) is titrated prior to addition of the solution of step(b) to step (c);
- optionally, wherein said ore or said material grounded to reduce the particle size of said material prior to adding said material the leaching solution of step (d);
- and
- optionally, wherein concentration of said thiourea is monitored during step (e).
A method of leaching mercury from mercury-containing material, said method comprising
- a) mixing water and sulfuric acid to obtain an aqueous sulfuric acid solution;
- b) dissolving thiourea and sodium metabisulfite in an amount of the solution of step (a) to have total dissolution thiourea and sodium metabisulfite.
- c) adding the solution of step (b) to the remaining amount of acid solution made in step (a);
- d) adding a source of hypochlorite to the solution to step (c) to obtain a leaching solution;
- e) adding mercury-containing material to the solution of step (d) to start the leaching process;
- f) recovering mercury using an ion exchange resin.
A method of leaching a material, said method comprising:
- (i) preparing a solution by premixing and dissolving thiourea and SMB and adding the resulting thiourea/SMB solution to an aqueous sulfuric acid solution;
- (ii) adding a source of hypochlorite to the solution made in step (i) to obtain a leaching solution;
- (iii) adding said material chosen from an ore, a concentrate, and a metal-containing material, to the solution of step (ii) to start the leaching process;
- and
- (iv) recovering metal (e.g., using an ion exchange resin);
- wherein said thiourea in step (i) is titrated prior to addition to the sulfuric acid solution.
Dependencies are inferred from the claim text.