Enhanced metal recovery through oxidation in liquid and/or supercritical carbon dioxide

Patent metadata

Field	Value
Publication number	US-10167202-B2
Application number	US-201715419184-A
Country	US
Kind code	B2
Filing date	Jan 30, 2017
Priority date	Feb 23, 2016
Publication date	Jan 1, 2019
Grant date	Jan 1, 2019

Abstract

Process for enhanced metal recovery from, for example, metal-containing feedstock using liquid and/or supercritical fluid carbon dioxide and a source of oxidation. The oxidation agent can be free of complexing agent. The metal-containing feedstock can be a mineral such as a refractory mineral. The mineral can be an ore with high sulfide content or an ore rich in carbonaceous material. Waste can also be used as the metal-containing feedstock. The metal-containing feedstock can be used which is not subjected to ultrafine grinding. Relatively low temperatures and pressures can be used. The metal-containing feedstock can be fed into the reactor at a temperature below the critical temperature of the carbon dioxide, and an exotherm from the oxidation reaction can provide the supercritical temperature. The oxidant can be added to the reactor at a rate to maintain isothermal conditions in the reactor. Minimal amounts of water can be used as an extractive medium.

First claim

What is claimed is:

1. A method comprising:
oxidizing a metal-containing feedstock in a reactor with liquid and/or supercritical fluid carbon dioxide and at least one oxidant, to obtain a working slurry; and
adding an amount of water to the reactor,
wherein the oxidant is free of a complexing agent and optionally the metal-containing feedstock is not subjected to ultrafine grinding, and
wherein the amount of water used to achieve a water saturation level without excess water is between 0.5 to 10 liters per cubic meter of the working slurry.

2. The method of claim 1 , wherein the oxidant is free of complexing agent and the metal-containing feedstock is not subjected to ultrafine grinding.

3. The method of claim 1 , wherein the metal-containing feedstock is a mineral metal composition.

4. The method of claim 1 , wherein the metal-containing feedstock is a refractory mineral composition.

5. The method of claim 1 , wherein the metal-containing feedstock is a mineral metal composition comprising a high sulfide content or a high carbonaceous material content.

6. The method of claim 1 , wherein metal-containing feedstock is a waste composition.

7. The method of claim 1 , wherein aqueous alkali solution is added to the reactor.

8. The method of claim 1 , wherein oxidizing the feedstock is carried out with supercritical fluid carbon dioxide.

9. The method of claim 1 , wherein the metal-containing feedstock is fed into the reactor at a temperature below the critical temperature of the carbon dioxide, and an exotherm from an oxidation reaction provides the supercritical temperature.

10. The method of claim 1 , wherein the oxidant is added to the reactor at a rate to maintain isothermal conditions in the reactor.

11. A method comprising: oxidizing a metal-containing feedstock in a reactor with liquid and/or supercritical fluid carbon dioxide and at least one oxidant, wherein the oxidant is free of complexing agent and optionally the metal-containing feedstock is not subjected to ultrafine grinding, wherein aqueous alkali solution is added to the reactor.

12. The method of claim 11 , wherein the metal-containing feedstock is not subjected to ultrafine grinding.

13. The method of claim 11 , wherein the metal-containing feedstock is a mineral metal composition.

14. The method of claim 11 , wherein the metal-containing feedstock is a refractory mineral composition.

15. The method of claim 11 , wherein the metal-containing feedstock is a mineral metal composition comprising a high sulfide content or a high carbonaceous material content.

16. The method of claim 11 , wherein metal-containing feedstock is a waste composition.

17. The method of claim 11 , wherein oxidizing the feedstock is carried out with supercritical fluid carbon dioxide.

18. The method of claim 11 , wherein the metal-containing feedstock is fed into the reactor at a temperature below the critical temperature of the carbon dioxide, and an exotherm from an oxidation reaction provides the supercritical temperature.

19. The method of claim 11 , wherein the oxidant is added to the reactor at a rate to maintain isothermal conditions in the reactor.

20. The method of claim 11 , wherein an amount of water used to achieve a water saturation level without excess water is between 0.5 and 10 liters per cubic meter of a working slurry.

Assignees

• Univ King Abdullah Sci & Tech

Inventors

• Blanco Mario
• Buttner Ulrich

Classifications

• C01G49/14 Primary

  Sulfates {(C01G49/0018 takes precedence)} · CPC title

• C22B3/12

  in inorganic alkaline solutions · CPC title

• C22B1/11

  Removing sulfur, phosphorus or arsenic other than by roasting · CPC title

• Y02P20/54

  using solvents, e.g. supercritical solvents or ionic liquids · CPC title

• Y02P10/20

  Recycling · CPC title