Moderately oxidized polysaccharide depressants for use in iron ore flotation processes

Patent metadata

Field	Value
Publication number	US-10589293-B2
Application number	US-201615275869-A
Country	US
Kind code	B2
Filing date	Sep 26, 2016
Priority date	Oct 8, 2015
Publication date	Mar 17, 2020
Grant date	Mar 17, 2020

Abstract

Depressants comprising a moderately oxidized polysaccharide having about 0.05 to about 4.5 mmol of anionic charge per gram at a pH of about 6 to about 7, or about 0.2 to about 5 mmol of anionic charge per gram at a pH of about 10 to about 11.2, are provided. Also disclosed are processes for enriching a desired mineral from an ore comprising the desired mineral and gangue, wherein the process comprises carrying out a flotation process in the presence of one or more of the depressants.

First claim

I claim:

1. A depressant comprising a moderately oxidized polysaccharide having about 0.05 to about 4.5 mmol of anionic charge per gram at a pH of about 6 to about 7, about 0.05 to about 5 mmol of anionic charge per gram at a pH of about 7 to about 8, about 0.2 to about 5 mmol of anionic charge per gram at a pH of about 10 to about 11.2, or about 0.2 to about 5 mmol of anionic charge per gram at a pH of about 10.5.

2. The depressant of claim 1 , wherein the moderately oxidized polysaccharide has about 0.06 to about 0.11 mmol of anionic charge per gram at a pH of about 6 to about 7, or about 0.23 to about 0.36 mmol of anionic charge per gram at a pH of about 10 to about 11.2.

3. The depressant of claim 1 , wherein the moderately oxidized polysaccharide is moderately oxidized starch.

4. A depressant comprising a moderately oxidized polysaccharide prepared by heating a mixture of a polysaccharide, one or more bases and one or more oxidizing agents in water.

5. The depressant of claim 4 , wherein the polysaccharide is starch.

6. The depressant of claim 4 , wherein the heating step is carried out at a temperature in the range of about 20° C. to about 100° C.

7. The depressant of claim 4 , wherein the heating step is carried out for about 15 min to about 6 hours.

8. The depressant of claim 4 , wherein the amount of water used in the treatment is the amount of water necessary to prepare a corn starch solution with a concentration of about 0.5% to about 50% by weight.

9. The depressant of claim 4 , wherein the one or more bases comprises sodium hydroxide.

10. The depressant of claim 4 , wherein the one or more oxidizing agents comprises hydrogen peroxide.

11. The depressant of claim 5 , wherein the starch is cornstarch, the heating step is carried out for about 30 minutes to about 5 hours at a temperature in the range of about 55° C. to about 95° C., the amount of water used in the treatment is the amount of water necessary to prepare a corn starch solution with a concentration of about 0.5% to about 10% by weight, the one or more bases comprises sodium hydroxide, and the one or more oxidizing agents comprises hydrogen peroxide.

12. A composition comprising: one or more depressants according to claim 1 , and a solvent.

13. The composition of claim 12 , wherein the solvent is water.

14. A process for enriching a desired mineral from an ore comprising the desired mineral and gangue, wherein the process comprises carrying out a flotation process in the presence of one or more depressants according to claim 1 .

15. The process of claim 14 , wherein the desired mineral is an iron-containing mineral.

16. The process of claim 14 , wherein the gangue comprises oxides of silica, silicates or siliceous materials.

17. The process of claim 14 , wherein the flotation process is a reverse cationic flotation process.

18. The process of claim 14 , wherein the process improves the grade of iron from iron ore such that the grade of the recovered iron is at least about 64%.

19. The process of claim 14 , wherein the process reduces the amount of silica in the iron ore to less than about 10%.

20. The process of claim 14 , wherein the flotation process is a reverse cationic flotation of iron ore.

Assignees

• Kemira Oyj

Inventors

• Wilson Duane C

Classifications

• B03D1/016 Primary

  Macromolecular compounds · CPC title

• C08B37/00

  Preparation of polysaccharides not provided for in groups C08B1/00 - C08B35/00; Derivatives thereof (cellulose D21; {microbiological processes C12P}) · CPC title

• C08B31/18

  Oxidised starch · CPC title

• B03D1/02

  Froth-flotation processes · CPC title

• B03D2201/06

  Depressants · CPC title