Cellulose-based derivatives as chemical aids for mineral enrichment in froth flotation

Patent metadata

Field	Value
Publication number	US-12364992-B2
Application number	US-201916968202-A
Country	US
Kind code	B2
Filing date	Jan 13, 2019
Priority date	Feb 9, 2018
Publication date	Jul 22, 2025
Grant date	Jul 22, 2025

Abstract

Frother composition and method of concentrating minerals by flotation. The method comprises providing an aqueous slurry formed by the minerals in finely divided form in water; optionally adding a collector to render the mineral hydrophobic; subjecting the slurry thus obtained to flotation in a flotation cell aerated to form bubbles; and recovering the hydrophobic mineral particles together with the froth to form a concentrate. In the method, an amphiphilic cellulose derivative, is used as such or in combination with a second surfactant as a frother to promote the formation of a stable froth on top of the slurry in the flotation cell. Hydroxypropyl methyl cellulose or hydroxyethyl methyl cellulose are combined with at least one non-ionic organic surfactant or polyglycol esters, for providing a frother. The novel cellulose-based frothers can be used in mineral processing plants to allow for processing of larger quantities of minerals without significant modification of existing facilities.

First claim

The invention claimed is:

1. A composition comprising:
amphiphilic cellulose as a surfactant in combination with a non-ionic surfactant, wherein the non-ionic surfactant is selected from the group consisting of:
methyl isobutyl carbinol;
polyglycols having the formula R(X) y OH, wherein R stands for H or C m H 2m+1 and X stands for propylene oxide (—C 3 H 6 O—) or ethylene oxide (—C 2 H 4 O—), and y stands for an integer of 1 to 6 and m stands for an integer of 1 to 6;
alcohols having the formula C p H 2p+1 OH, wherein p stands for an integer of 1 to 10;
and combinations thereof, and

wherein the composition is a frother composition.

2. The composition according to claim 1 , wherein the amphiphilic cellulose is selected from non-ionic cellulose ethers.

3. The composition according to claim 1 , wherein the amphiphilic cellulose is a non-ionic cellulose ether having Formula I:

wherein
each R is independently selected from the group consisting-of hydrogen, lower alkyl and hydroxyl (lower alkyl), and
n stands for an integer in the range of 2 to 100.

4. The composition according to claim 3 , wherein, in each repeating unit of Formula I, substituents R stand for at least one hydrogen, at least one alkyl group, and at least one hydroxyethyl or hydroxypropyl group.

5. The composition according to claim 3 , wherein in the amphiphilic cellulose of Formula I, R is H or CH 3 and n is 4 to 100.

6. The composition according to claim 1 , wherein the amphiphilic cellulose is selected from the group consisting of hydroxypropyl methyl cellulose, hydroxyethyl methyl cellulose, and combinations thereof.

7. The composition according to claim 1 , wherein the amphiphilic cellulose is a non-ionic cellulose ether having an average molecular weight (Mw) in the range of 500 to 5000 Da.

8. The composition according to claim 1 , wherein the composition contains in addition to amphiphilic cellulose at least one further surfactant selected from non-ionic organic surfactants.

9. The composition according to claim 1 , wherein a mass ratio of the amphiphilic cellulose to the non-ionic surfactant ranges from 0.1:10 to 10:0.1.

10. A method of concentrating minerals by flotation, comprising
providing an aqueous slurry formed by the minerals in finely divided form in water;
optionally adding a collector to render the mineral hydrophobic or to increase the hydrophobicity of the minerals;
subjecting the slurry thus obtained to flotation in a flotation cell aerated to form bubbles; and
recovering the hydrophobic mineral particles together with froth to form a concentrate; said method further comprising adding the frother composition of claim 1 to promote the formation of a stable froth on top of the slurry in the flotation cell.

11. The method according to claim 10 , wherein sodium isobutyl xanthate is added as a collector.

12. The method according to claim 10 , wherein the aqueous slurry is mixed with zinc sulphate.

13. The method according to claim 10 , wherein the concentration of mineral particles in the slurry is in the range of 10 to 50% by weight.

14. The method according to claim 10 , wherein the frother is added so as to obtain a concentration of 10 to 100 ppm.

15. The method according to claim 10 , wherein the pH of the slurry is adjusted to about 10 to 12.5 during flotation.

16. The method according to claim 10 , wherein the frother comprises an amphiphilic cellulose ether having Formula I:

wherein
each R is independently selected from the group of hydrogen, lower alkyl, and hydroxyl (lower alkyl), and
n stands for an integer in the range of 2 to 100.

17. The method according to claim 16 , wherein, in each repeating unit of Formula I, substituents R stand for at least one hydrogen, at least one lower alkyl group, and at least one hydroxypropyl group.

18. The method according to claim 16 , wherein, in the amphiphilic cellulose ether of Formula I, R is H or CH 3 and n is 4 to 100.

19. The method according to claim 10 , wherein the frother comprises an amphiphilic cellulose selected from the group consisting of hydroxypropyl methyl cellulose, hydroxyethyl methyl cellulose, and combinations thereof.

20. The method according to claim 10 , wherein the amphiphilic cellulose is a non-ionic cellulose ether having an average molecular weight (Mw) in the range of 500 to 5000 Da.

21. The method according to claim 10 , wherein the second surfactant comprises a non-ionic organic surfactant.

22. The method according to claim 10 , wherein the second surfactant is a non-ionic surfactant selected from the group consisting of
methyl isobutyl carbinol;
polyglycols having the formula R(X) y OH, wherein R stands for H or C m H 2m+1 and X stands for, propylene oxide (—C 3 H 6 O—) or ethylene oxide (—C 2 H 4 O—), and y stands for an integer of 1 to 6 and m stands for an integer of 1 to 6;
alcohols having the formula C p H 2p+1 OH, wherein p stands for an integer of 1 to 10;
and combinations thereof.

23. The method according to claim 10 , wherein the amphiphilic cellulose is used together with a non-ionic surfactant selected from the group consisting of alcohols, methyl isobutyl carbinol, polyglycol ethers, and combinations thereof.

24. The method according to claim 23 , wherein the amphiphilic cellulose is used together with a non-ionic surfactant at a mass ratio ranging from 0.1:10 to 10:0.1.

25. The method according to claim 10 , wherein the amphiphilic cellulose and the second surfactant are added simultaneously to the slurry.

26. The method according to claim 10 , wherein the amphiphilic cellulose and the second surfactant are sequentially added to the slurry.

Assignees

• Aalto Univ Foundation Sr

Inventors

• Nuorivaara Ted
• Serna Guerrero Rodrigo

Classifications

• C22B1/00

  Preliminary treatment of ores or scrap · CPC title

• C01B33/12

  Silica; Hydrates thereof, e.g. lepidoic silicic acid · CPC title

• B03D2203/02

  Ores · CPC title

• B03D2203/008

  Water purification, e.g. for process water recycling · CPC title

• B03D2201/04

  Frothers · CPC title