Supramolecular gold stripping from activated carbon using alpha-cyclodextrin

Patent metadata

Field	Value
Publication number	US-2024375084-A1
Application number	US-202118258431-A
Country	US
Kind code	A1
Filing date	Dec 21, 2021
Priority date	Dec 21, 2020
Publication date	Nov 14, 2024
Grant date	—

Abstract

Disclosed herein are compositions, methods, and systems for supramolecular gold stripping where the composition comprises a surface-bound, linear gold anion and a solution comprising a molecular receptor that facilitates the transfer of the linear gold anion from the surface to the solution.

First claim

1 . A composition comprising a surface-bound, linear gold anion and a solution, the solution comprising a molecular receptor.

2 . The composition of claim 1 , wherein the molecular receptor is α-cyclodextrin (α-CD).

3 . The composition of claim 1 , wherein the linear gold anion is Au(CN) 2 − .

4 . The composition of claim 1 , wherein the composition comprises an adduct formed from the molecular receptor and the linear gold anion.

5 . The composition of claim 1 , wherein the surface is the surface of activated carbon.

6 . The composition of claim 1 , wherein the solution is an aqueous solution

7 . The composition of claim 1 , wherein the solution comprising the molecular receptor at a concentration of 1-10 w/v %.

8 . A method for gold stripping, the method comprising contacting a surface-bound, linear gold anion with a solution comprising a molecular receptor under conditions sufficient for transferring the linear gold anion from the surface into the solution.

9 . The method of claim 8 , wherein the surface-bound linear gold anion is contacted with the solution comprising the molecular receptor in the presence of a surface-bound contaminant and the linear gold-anion is selectively transferred from the surface into the solution.

10 . The method of claim 8 , wherein the linear gold anion is Au(CN) 2 − .

11 . The method of claim 10 , wherein the contaminant is Ag(CN) 2 − .

12 . The method of claim 8 , wherein the molecular receptor is α-cyclodextrin (α-CD).

13 . The method of claim 8 , wherein solution comprises an adduct formed from the molecular receptor and the linear gold anion.

14 . The method of claim 8 , wherein the surface is the surface of activated carbon.

15 . The method of claim 8 , wherein the solution is an aqueous solution.

16 . The method of claim 8 , wherein the solution comprising the molecular receptor at a concentration of 1-10 w/v %.

17 . The method of claim 8 , wherein the linear gold anion is transferred from the surface into the solution at a temperature between about 10° C. and about 40° C.

18 . The method of claim 8 further comprising recovering gold from the solution.

19 . The method of claim 18 , wherein the gold is recovered electrolytically.

20 . An electrolytic system comprising an electrode and an electrolyte comprising a molecular receptor and a linear gold anion.

21 . (canceled)

Assignees

• Univ Northwestern

Inventors

• Stoddart James Fraser
• Liu Wenqi

Classifications

• C25C1/20

  of noble metals · 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

• C22B3/205

  using adducts or inclusion complexes · CPC title

• B01J20/3416

  of sorbents or filter aids comprising free carbon, e.g. activated carbon · CPC title

• B01J20/20

  comprising free carbon; comprising carbon obtained by carbonising processes · CPC title