Method of improving gold recovery in a cyanide leaching circuit

Patent metadata

Field	Value
Publication number	US-2021301371-A1
Application number	US-202117216789-A
Country	US
Kind code	A1
Filing date	Mar 30, 2021
Priority date	Mar 30, 2020
Publication date	Sep 30, 2021
Grant date	—

Abstract

This disclosure provides a method of improving gold recovery in a cyanide leaching circuit comprising a gold ore slurry. The method includes the step of providing a gold recovery additive chosen from polyacrylic acid, copolymers of acrylic acid and a sulfonated co-monomer, and combinations thereof, wherein the additive has a weight average molecular weight of from about 500 to about 10,000 g/mol. The method also includes the step of combining the gold recovery additive with the gold ore slurry in the cyanide leaching circuit, wherein the gold recovery additive is present in an amount of from about 10 to about 1000 g per ton of dry gold ore to improve the recovery of gold from the gold ore slurry.

First claim

What is claimed is:

1 . A method of improving gold recovery in a cyanide leaching circuit comprising a gold ore slurry, said method comprising the steps of:
providing a gold recovery additive chosen from polyacrylic acid, copolymers of acrylic acid and a sulfonated co-monomer, and combinations thereof, wherein the additive has a weight average molecular weight of from about 500 to about 10,000 g/mol; combining the gold recovery additive with the gold ore slurry in the cyanide leaching circuit, wherein the gold recovery additive is present in an amount of from about 10 to about 1000 g per ton of dry gold ore to improve the recovery of gold from the gold ore slurry.

2 . The method of claim 1 wherein the gold recovery additive is polyacrylic acid having a weight average molecular weight of about 1,000 to about 6,000 g/mol.

3 . The method of claim 1 wherein the gold recovery additive is polyacrylic acid having a weight average molecular weight of about 2,000 to about 4,000 g/mol.

4 . The method of claim 1 wherein the gold recovery additive is a copolymer of acrylic acid and the sulfonated co-monomer.

5 . The method of claim 1 wherein the gold recovery additive is a copolymer of acrylic acid and the sulfonated co-monomer wherein the sulfonated co-monomer is chosen from 2-acrylamido-2-methylpropane sulfonic acid, 2-methyl-2-propene-1-sulfonic acid, and combinations thereof.

6 . The method of claim 5 wherein the gold ore slurry has a grind density of from about 50 to about 80 percent of solids based on a total weight of the slurry.

7 . The method of claim 6 wherein the gold ore slurry has a leach density of from about 25 to about 50 percent of solids based on a total weight of the slurry.

8 . The method of claim 7 wherein the gold recovery additive is present in an amount of from about 100 to about 700 g per ton of dry gold ore.

9 . The method of claim 1 wherein the gold ore slurry has a grind density of from about 50 to about 80 percent of solids based on a total weight of the slurry.

10 . The method of claim 9 wherein the gold ore slurry has a leach density of from about 25 to about 50 percent of solids based on a total weight of the slurry.

11 . The method of claim 1 wherein the gold ore slurry has a leach density of from about 25 to about 50 percent of solids based on a total weight of the slurry.

12 . The method of claim 1 wherein the gold recovery additive is present in an amount of from about 100 to about 700 g per ton of dry gold ore.

13 . The method of claim 1 wherein the gold recovery additive is present in an amount of from about 625 g per ton of dry gold ore.

14 . The method of claim 1 wherein the step of combining occurs in a leaching tank of a carbon-in-leach or carbon-in-pulp process.

15 . The method of claim 1 wherein the step of combining occurs during a step of slurry pumping in the cyanide leaching circuit of a carbon-in-leach or carbon-in-pulp process.

16 . The method of claim 1 wherein the gold recovery additive and the gold ore slurry are free of an oil.

17 . The method of claim 1 wherein the gold recovery additive and the gold ore slurry are free of a cationic surfactant.

18 . The method of claim 1 wherein the step of combining occurs in a leaching tank of a carbon-in-leach or carbon-in-pulp process, wherein the gold ore slurry has a leach density of from about 25 to about 50 percent based on a total weight of the slurry, wherein the gold slurry has a grind density of about 60 percent based on a total weight of the slurry, and wherein the gold recovery additive and the gold ore slurry are free of an oil and a cationic surfactant.

19 . The method of claim 1 wherein the step of combining occurs in a leaching tank of a carbon-in-leach or carbon-in-pulp process, wherein the gold ore slurry has a leach density of from about 25 to about 50 percent based on a total weight of the slurry, wherein the gold slurry has a grind density of about 60 percent based on a total weight of the slurry, wherein the gold recovery additive is polyacrylic acid having a weight average molecular weight of about 2,000 to about 4,000 g/mol, and wherein the gold recovery additive and the gold ore slurry are free of an oil and a cationic surfactant.

20 . The method of claim 1 wherein the step of combining occurs in a leaching tank of a carbon-in-leach or carbon-in-pulp process, wherein the gold ore slurry has a leach density of from about 25 to about 50 percent based on a total weight of the slurry, wherein the gold slurry has a grind density of about 60 percent based on a total weight of the slurry, wherein the gold recovery additive is polyacrylic acid having a weight average molecular weight of about 2,000 to about 4,000 g/mol, wherein the gold recovery additive is present in an amount of about 625 g per ton of dry ore, and wherein the gold recovery additive and the gold ore slurry are free of an oil and a cationic surfactant.

Assignees

• Solenis Tech Lp

Inventors

• Bakeev Kirill N

Classifications

• Y02P10/20

  Recycling · CPC title

• C22B11/08 Primary

  by cyaniding · CPC title

• C22B3/06 Primary

  in inorganic acid solutions {, e.g. with acids generated in situ; in inorganic salt solutions other than ammonium salt solutions} · CPC title

• C22B11/04

  by wet processes (extraction of metal compounds by leaching in organic solutions C22B3/16; treatment or purification of solutions by liquid-liquid extraction C22B3/26) · CPC title