Method for producing aqueous solutions of cobalt sulphate

Patent metadata

Field	Value
Publication number	US-9416023-B2
Application number	US-201314412231-A
Country	US
Kind code	B2
Filing date	Jun 28, 2013
Priority date	Jul 10, 2012
Publication date	Aug 16, 2016
Grant date	Aug 16, 2016

Abstract

Process for preparing an aqueous cobalt sulfate solution having a pH of at least 4, wherein
(a) metallic cobalt is dissolved in aqueous sulfuric acid in an atmosphere of low-oxygen air, of hydrogen or of inert gas and (b) the resulting acidic cobalt sulfate solution is treated with oxygen, oxygen-comprising gas or with a substance which can release oxygen in an aqueous medium.

First claim

The invention claimed is:

1. A process for preparing an aqueous cobalt sulfate solution having a pH of at least 4, the process comprising:
(a) dissolving metallic cobalt in aqueous sulfuric acid in an atmosphere of hydrogen, of inert gas or of a nitrogen/oxygen mixture which comprises nitrogen and oxygen in a volume ratio of from 6:1 to 100:1, thereby obtaining an acidic cobalt sulfate solution, and
(b) treating the acidic cobalt sulfate solution with oxygen, oxygen-comprising gas or a substance releasing oxygen in an aqueous medium.

2. The process according to claim 1 , wherein the substance releasing oxygen is selected from the group consisting of H 2 O 2 , an inorganic peroxide, an inorganic persulfate, and an inorganic percarbonate.

3. The process according to claim 1 , wherein said treating (b) is carried out in the presence of metallic cobalt.

4. The process according to claim 1 , wherein said dissolving (a) is carried out at a temperature of from 80 to 110° C.

5. The process according to claim 1 , wherein an aqueous sulfuric acid having a concentration of from 10 to 30% by weight is used in said dissolving (a).

6. The process according to claim 1 , wherein said treating (b) is carried out at a temperature of from 80 to 110° C.

7. The process according to claim 1 , wherein the aqueous cobalt sulfate solution has an Na + content of not more than 1000 ppm, based on cobalt.

8. The process according to claim 1 , wherein the aqueous cobalt sulfate solution has a content of iron ions of not more than 50 ppm, based on cobalt.

9. The process according to claim 1 , wherein the aqueous cobalt sulfate solution has a content of calcium ions of not more than 50 ppm, based on cobalt.

10. The process according to claim 1 , wherein the aqueous cobalt sulfate solution has a content of copper(II) ions of not more than 50 ppm, based on cobalt.

11. The process according to claim 1 , wherein the aqueous cobalt sulfate solution has a content of aluminum ions of not more than 50 ppm, based on cobalt.

12. The process according to claim 1 , wherein the aqueous cobalt sulfate solution has a content of chromium(III) ions of not more than 50 ppm, based on cobalt.

13. The process according to claim 1 , further comprising:
(c) purifying the aqueous cobalt sulfate solution via a filter.

14. The process according to claim 1 , further comprising:
(d) purifying the aqueous cobalt sulfate solution via an ion exchanger.

15. The process according to claim 1 , wherein the acidic cobalt sulfate solution is (b) treated with a substance releasing oxygen selected from the groups consisting of H 2 O 2 , an inorganic peroxide, an inorganic persulfate, and an inorganic percarbonate.

16. The process according to claim 1 , wherein the acidic cobalt sulfate solution is (b) treated with an oxygen-comprising gas.

17. The process according to claim 16 , wherein the oxygen-comprising gas is air.

18. The process according to claim 1 , wherein the metallic cobalt is (a) dissolved in aqueous sulfuric acid in an atmosphere of a nitrogen/oxygen mixture which comprises nitrogen and oxygen in a volume ratio from 6:1 to 100:1.

19. The process according to claim 1 , wherein the metallic cobalt is (a) dissolved in aqueous sulfuric acid in an atmosphere of inert gas.

20. The process according to claim 19 , wherein the atmosphere of inert gas is nitrogen.

Assignees

• Basf Se

Inventors

• Schroedle Simon
• Wagner Oliver

Classifications

• C01G51/10 Primary

  Sulfates · CPC title

• C01P2006/80

  Compositional purity · CPC title

• C01G51/01

  Preparation or separation involving a liquid-liquid extraction, an adsorption or an ion-exchange · CPC title