Alternative additives to enhance slurry dewatering

Patent metadata

Field	Value
Publication number	US-10457584-B2
Application number	US-201815893279-A
Country	US
Kind code	B2
Filing date	Feb 9, 2018
Priority date	Feb 26, 2014
Publication date	Oct 29, 2019
Grant date	Oct 29, 2019

Abstract

The invention provides methods and compositions for improving dewatering of mineral slurry. The method comprises adding an R-Succinic Compound (such as octadecenyl succinic acid, hexadecenyl succinic acid, and/or dodecenyl succinic acid) to the slurry. The R-Succinic Compound removes water that would otherwise be trapped within the filtered slurry cake.

First claim

The invention claimed is:

1. A method of separating alumina trihydrate crystals from an alumina trihydrate bearing slurry, the method comprising: combining an alkenyl succinic anhydride and water; adding the combination to the slurry; and separating alumina trihydrate crystals from the slurry.

2. The method of claim 1 wherein an R-succinic compound forms in situ from the alkenyl succinic anhydride, and wherein the R-succinic compound has a structure selected from formula (I) or formula (II), a conjugate acid-base of the R-succinic compound having a structure selected from formula (I) or formula (II), and combinations thereof; wherein formula (I) is

and formula (II) is

and wherein R and R′ are independent, distinct, and represent alkyl, alkenyl, or aromatic hydrocarbon groups containing 1-30 carbon atoms.

3. The method of claim 1 wherein the alkenyl succinic anhydride undergoes ring opening in the water, or in the slurry.

4. The method of claim 1 wherein the separating comprises crystallizing.

5. The method of claim 4 wherein the separating further comprises filtering.

6. The method of claim 1 wherein the alumina trihydrate bearing slurry is a caustic Bayer liquor.

7. The method of claim 1 wherein the composition comprises 5-80 mg alkenyl succinic anhydride per 200 mL water.

8. The method of claim 1 wherein the composition is added upstream of the calcination stage.

9. The method of claim 1 wherein the composition is added to one or more precipitation tanks.

10. A method of separating alumina trihydrate crystals from an alumina trihydrate bearing slurry, the method comprising: adding a composition comprising water, an R-succinic compound and an alkenyl succinic anhydride to the slurry; and separating alumina trihydrate crystals from the slurry, wherein the R-succinic compound has a structure selected from formula (I) or formula (II), a conjugate acid-base of the R-succinic compound having a structure selected from formula (I) or formula (II), and combinations thereof; wherein formula (I) is

and formula (II) is

and wherein R and R′ are independent, distinct, and represent alkyl, alkenyl, or aromatic hydrocarbon groups containing 1-30 carbon atoms.

11. The method of claim 10 wherein the alkenyl succinic anhydride undergoes ring opening in the water, or in the slurry.

12. The method of claim 10 wherein the separating comprises crystallizing.

13. The method of claim 10 wherein the separating further comprises filtering.

14. The method of claim 10 wherein the alumina trihydrate bearing slurry is a caustic Bayer liquor.

15. The method of claim 10 wherein the composition comprises 5 mg-80 mg alkenyl succinic anhydride per 200 mL water.

16. The method of claim 10 wherein the composition is added upstream of the calcination stage.

17. The method of claim 10 wherein the composition is added to one or more precipitation tanks.

Assignees

• Ecolab Usa Inc

Inventors

• Urbani Carl N

Classifications

• F26B5/005

  by dipping them into or mixing them with a chemical liquid, e.g. organic; chemical, e.g. organic, dewatering aids (F26B3/005 takes precedence; using chemical vapours or gases F26B21/40) · CPC title

• C02F2103/10

  from quarries or from mining activities · CPC title

• C22B3/22

  by physical processes, e.g. by filtration, by magnetic means {, or by thermal decomposition} (treatment or purification of solutions by liquid-liquid extraction C22B3/26) · CPC title

• C01F7/148 Primary

  Separation of the obtained hydroxide, e.g. by filtration or dewatering · CPC title

• C02F11/14 Primary

  with addition of chemical agents · CPC title