Process for copper and/or precious metal recovery
A process for recovery of metal comprising copper and/or a precious metal from a metal containing material, including the steps of: leaching the metal containing material with an alkaline lixiviant and an amino acid or derivative thereof in order to produce a metal containing leachate; and extracting the metal from the leachate.
1. A process for recovery of metal comprising copper and/or a precious metal from a metal containing material, including the steps of:
leaching the metal containing material with an aqueous alkaline solution having a pH of at least 9 and containing a lixiviant comprising an amino acid or derivative thereof in order to produce a metal containing leachate; and
extracting the metal from the leachate,
wherein the amino acid comprises glycine.
2. The process of claim 1 , wherein the metal comprises a precious metal and the leaching step comprises leaching a precious metal containing material with an alkaline solution containing an oxidant and the amino acid or derivative thereof at an elevated temperature in order to produce a precious metal containing leachate.
3. The process of claim 2 , wherein the oxidant is a peroxide, manganese dioxide, or an oxygen containing gas.
4. The process of claim 3 , wherein the oxidant is hydrogen peroxide and the amount of hydrogen peroxide in solution is at least 0.005 wt %, and is a maximum of 5 wt %.
5. The process of claim 3 , wherein the leachant further includes a leaching catalyst comprising cupric (copper(II)) species, present in a concentration of at least 1mM and up to 10 mM.
6. The process of claim 2 , wherein the elevated temperature is at least 30 ° C.
7. The process of claim 1 , wherein the leaching is conducted at ambient temperature.
8. The process of claim 1 , wherein the material comprises ores, concentrates or tailings.
9. The process of claim 1 , wherein the process comprises heap leaching, in-situ leaching, in-place leaching, vat leaching or tank leaching.
10. The process of claim 1 , wherein the amino acid derivative comprises a peptide.
11. The process of claim 1 , wherein the concentration of amino acid in the leaching solution is at least 0.001 M and is a maximum of 2 M.
12. The process of claim 1 , wherein the pH is within a range from 9 to 13.
13. The process of claim 1 , wherein the pH is above 10.
14. A differential leaching process for recovery of copper and precious metal from a copper and precious metal containing material, including the steps of:
leaching the copper and precious metal containing material with an alkaline solution containing a lixiviant comprising an amino acid or derivative thereof under first conditions comprising ambient temperature and/or the absence of an oxidant in order to produce a copper containing leachate and precious metal containing residue;
leaching the precious metal containing residue with an alkaline solution containing a lixiviant comprising an amino acid or derivative thereof under second conditions comprising elevated temperature and/or the presence of an oxidant, in order to produce a precious metal containing leachate;
extracting the copper from the copper containing leachate; and
extracting the precious metal from the precious metal containing leachate.
15. A process for recovery of metal comprising copper and/or a precious metal from a metal containing material, including the steps of:
leaching the metal containing material with an aqueous alkaline solution containing a lixiviant comprising an amino acid derivative in order to produce a metal containing leachate, wherein the amino acid derivative comprises a peptide; and
extracting the metal from the leachate.