Method for extracting and enriching gold with selenide

Patent metadata

Field	Value
Publication number	US-11434543-B2
Application number	US-202016992543-A
Country	US
Kind code	B2
Filing date	Aug 13, 2020
Priority date	Oct 31, 2019
Publication date	Sep 6, 2022
Grant date	Sep 6, 2022

Abstract

A method for extracting and enriching gold with a selenide includes: mixing an isocyanate and a selenium-containing compound of a formula of HO—R—Se—R—OH in a solvent to obtain a mixture system, where R is selected from linear or branched C2 to C11 alkylene groups; adding a tin-based catalyst into the mixture system to activate a reaction, drying the mixture system after the reaction, and obtaining a powdery selenium-containing polymer by grinding; immersing the selenium-containing polymer in an aqueous solution containing gold ions to allow gold to be extracted from the aqueous solution; and removing the selenium-containing polymer attached to a surface of extracted gold, thereby obtaining an extracted and enriched gold.

First claim

What is claimed is:

1. A method for extracting and enriching gold with a selenide, comprising:
mixing an isocyanate and a selenium-containing compound of a formula of HO—R—Se—R—OH in a solvent according to a mass ratio of the isocyanate to the selenium-containing compound of (0.2 to 2):1 to obtain a mixture system with a mass concentration of the selenium-containing compound of 0.1 to 1 g/mL, where R is selected from linear or branched C 2 to C 11 alkylene groups;
adding a tin-based catalyst in an amount of 20 to 100 μL per 1 g of the selenium-containing compound into the mixture system to activate a reaction, drying the mixture system after the reaction, and obtaining a powdery selenium-containing polymer by grinding;
immersing the selenium-containing polymer in an aqueous solution containing gold ions to allow gold to be extracted from the aqueous solution; and
removing the selenium-containing polymer attached to a surface of extracted gold, thereby obtaining an extracted and enriched gold.

2. The method according to claim 1 , wherein the isocyanate is selected from any one of toluene diisocyanate, hexamethylene diisocyanate, methylenediphenyl diisocyanate and isophorone diisocyanate.

3. The method according to claim 1 , wherein the solvent is selected from any one or more of dichloromethane, acetone, tetrahydrofuran, diethyl ether, n-hexane and n-pentane.

4. The method according to claim 1 , wherein the tin-based catalyst is selected from any one or more of dibutyltin dilaurate, stannous octoate, dibutyltin diacetate and bis(dodecylthio)dibutyltin.

5. The method according to claim 1 , wherein the aqueous solution containing gold ions is selected from a chloroauric acid solution or a CPU circuit board leaching solution.

6. The method according to claim 1 , wherein the selenium-containing compound of the formula of HO—R—Se—R—OH is prepared by:
providing a selenium powder and sodium borohydride in a reaction device, and adding absolute ethanol in the reaction device for reaction until no gas is generated;
introducing nitrogen to remove the gas in the reaction device;
dissolving a bromine-substituted alkyl alcohol into tetrahydrofuran to obtain a bromine-substituted alkyl alcohol solution;
injecting the bromine-substituted alkyl alcohol solution into the reaction device to allow a reaction to be performed at 50° C. for 8 h to obtain the selenium-containing compound; and
purifying the selenium-containing compound.

7. The method according to claim 1 , further comprising:
stirring the mixture system at 1000 r/min for a period of 1 min to 30 min.

8. The method according to claim 1 , wherein gold extraction is performed at 37° C. in a constant temperature shaker in the dark for 24 h.

9. The method according to claim 1 , wherein removing the selenium-containing polymer attached to the surface of the extracted gold comprises:
placing the extracted gold in tetrahydrofuran; and
performing an ultrasonic vibration to dissolve the selenium-containing polymer attached to the surface of the extracted gold to obtain a high-purity gold.

10. A method for extracting and enriching gold with a selenide, comprising:
mixing an isocyanate, a selenium-containing compound of a formula of HO—R—Se—R—OH and a crosslinking agent in a solvent according to a mass ratio of the isocyanate, the selenium-containing compound and the crosslinking agent of (0.6 to 3):1:(0.2 to 1) to obtain a mixture system with a mass concentration of the selenium-containing compound of 0.1 to 1 g/mL, where each R is selected from linear or branched C 2 to C 11 alkylene groups;
adding a tin-based catalyst in an amount of 20 to 100 μL per 1 g of the selenium-containing compound into the mixture system to activate a reaction, and obtaining a selenium-containing porous material after the reaction;
immersing the selenium-containing porous material in an aqueous solution containing gold ions to allow gold to be extracted from the aqueous solution; and
removing the selenium-containing porous material attached to a surface of the extracted gold by calcination for 2 to 5 h, thereby obtaining an extracted and enriched gold.

11. The method according to claim 10 , wherein the isocyanate is selected from any one of toluene diisocyanate, hexamethylene diisocyanate, methylenediphenyl diisocyanate and isophorone diisocyanate.

12. The method according to claim 10 , wherein the solvent is selected from any one or more of dichloromethane, acetone, tetrahydrofuran, diethyl ether, n-hexane and n-pentane.

13. The method according to claim 10 , wherein the crosslinking agent is selected from any one or more of glycerine, triethanolamine and pentaerythritol.

14. The method according to claim 10 , wherein the tin-based catalyst is selected from any one or more of dibutyltin dilaurate, stannous octoate, dibutyltin diacetate and bis(dodecylthio)dibutyltin.

15. The method according to claim 10 , wherein the aqueous solution containing gold ions is selected from a chloroauric acid solution or a CPU circuit board leaching solution.

16. The method according to claim 10 , wherein R is selected from any group of —CH 2 CH 2 —, —CH 2 CH 2 CH 2 —, —(CH 2 ) 4 —, —(CH 2 ) 5 —, —(CH 2 ) 6 —, —(CH 2 ) 7 —, —(CH 2 ) 8 —, —(CH 2 ) 9 —, —(CH 2 ) 10 — and —(CH 2 ) 11 —.

17. The method according to claim 10 , wherein the selenium-containing compound of the formula of HO—R—Se—R—OH is prepared by:
providing a selenium powder and sodium borohydride in a reaction device, and adding absolute ethanol in the reaction device for reaction until no gas is generated;
introducing nitrogen to remove the gas in the reaction device;
dissolving a bromine-substituted alkyl alcohol into tetrahydrofuran to obtain a bromine-substituted alkyl alcohol solution;
injecting the bromine-substituted alkyl alcohol solution into the reaction device to allow a reaction to be performed at 50° C. for 8 h to obtain the selenium-containing compound; and
purifying the selenium-containing compound.

18. The method according to claim 10 , further comprising:
stirring the mixture system at 1000 r/min for a period of 1 min to 30 min.

19. The method according to claim 10 , wherein gold extraction is performed at 37° C. in a constant temperature shaker in the dark for 24 h.

20. The method according to claim 10 , wherein the calcination is performed in a muffle furnace at a temperature of 550 to 1000° C.

Assignees

• Univ Tsinghua

Inventors

• Xu Huaping
• Dai Yiheng
• Xiang Wentian
• Zheng Ke

Classifications

• B01J20/3028

  Granulating, agglomerating or aggregating · CPC title

• C22B3/24 Primary

  by adsorption on solid substances, e.g. by extraction with solid resins · CPC title

• B01J20/3078

  Thermal treatment, e.g. calcining or pyrolizing · 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

• C22B11/042

  Recovery of noble metals from waste materials · CPC title