Recycling of lead- and tin-based materials

Patent metadata

Field	Value
Publication number	US-2021317001-A1
Application number	US-201917265113-A
Country	US
Kind code	A1
Filing date	Aug 2, 2019
Priority date	Aug 3, 2018
Publication date	Oct 14, 2021
Grant date	—

Abstract

This invention relates to a process for obtaining lead (Pb) and/or tin (Sn) from a lead- and/or tin-based material using a deep eutectic solvent.

First claim

1 . A method comprising:
combining a lead- and/or tin-based material, or a mixture thereof, and a compound comprising a carboxylic acid moiety in the presence of a deep eutectic solvent; and precipitating lead and/or tin carboxylate; wherein the lead-based material comprises Pb, PbO, PbO 2 , PbSO 4 , PbCO 3 , (PbCO 3 ) 2 .Pb(OH) 2 , PbTe, or APbX 3 , or a mixture thereof, wherein A is CH 3 NH 3 or HC(NH 2 ) 2 and each X is independently I, Br or Cl; and wherein the tin-based material comprises ASnX 3 , wherein A is CH 3 NH 3 or HC(NH 2 ) 2 and each X is independently I, Br or Cl.

2 . The method of claim 1 comprising:
combining a lead- and/or tin-based material, or a mixture thereof, with a deep eutectic solvent;
adding a compound comprising a carboxylic acid moiety; and
precipitating lead and/or tin carboxylate;
wherein the lead-based material comprises Pb, PbO, PbO 2 , PbSO 4 , PbCO 3 , (PbCO 3 ) 2 .Pb(OH) 2 , PbTe, or APbX 3 , or a mixture thereof, wherein A is CH 3 NH 3 or HC(NH 2 ) 2 and each X is independently I, Br or Cl; and
wherein the tin-based material comprises ASnX 3 , wherein A is CH 3 NH 3 or HC(NH 2 ) 2 and each X is independently I, Br or Cl.

3 . The method of claim 1 comprising:
combining a lead- and/or tin-based material, or a mixture thereof, with a deep eutectic solvent comprising a compound comprising a carboxylic acid moiety; and
precipitating lead and/or tin carboxylate;
wherein the lead-based material comprises Pb, PbO, PbO 2 , PbSO 4 , PbCO 3 , (PbCO 3 ) 2 .Pb(OH) 2 , PbTe, or APbX 3 , or a mixture thereof, wherein A is CH 3 NH 3 or HC(NH 2 ) 2 and each X is independently I, Br or Cl; and
wherein the tin-based material comprises ASnX 3 , wherein A is CH 3 NH 3 or HC(NH 2 ) 2 and each X is independently I, Br or Cl.

4 . The method of claim 1 , wherein the compound comprising a carboxylic acid moiety is a compound of formula:

wherein R is H or a straight or branched C 1-6 alkyl, substituted with 0-4 substituents selected from OH or COOH.

5 . The method of claim 1 , wherein the compound comprising a carboxylic acid moiety is a compound comprising at least two carboxylic acid moieties, preferably be a compound of formula:

wherein R′ is a straight or branched C 1-6 alkyl, substituted with 0-3 substituents selected from OH or COOH.

6 . The method of claim 1 , wherein the compound comprising a carboxylic acid moiety is actetic acid, oxalic acid or citric acid or a mixture thereof, optionally oxalic acid or citric acid or a mixture thereof, optionally oxalic acid.

7 . The method of claim 1 , wherein the deep eutectic solvent comprises a hydrogen bond donor and an ammonium salt or a metal chloride hydrate and a hydrogen bond donor.

8 . The method of claim 7 , wherein (a) the hydrogen bond donor is ethylene glycol, glycerol, propylene glycol, fructose, xylitol, erythritol, 1,6-hexanediol, urea, acetamide, 1-methyl urea, 1,3-dimethyl urea, 1,1-dimethyl urea, thiourea and benzamide, oxalic acid, malonic acid, benzoic acid, adipic acid, succinic acid, citric acid or water, or mixtures thereof; (b) the ammonium salt is choline chloride; and/or (c) the metal chloride hydrate is lithium chloride, sodium chloride, aluminium trichloride, tin chloride or zinc chloride, or mixtures thereof.

9 . The method of claim 1 , wherein the deep eutectic solvent is selected from:
a) a mixture of choline chloride and urea, preferably wherein the molar ratio is about 4:1 to 1:6, preferably in a 1:2 molar ratio; b) a mixture of choline chloride and ethylene glycol, preferably wherein the molar ratio is about 5:1 to 1:20, preferably in a 1:2 molar ratio; c) a mixture of choline chloride and propylene glycol, preferably wherein the molar ratio is about 5:1 to 1:20; d) a mixture of choline chloride and butanediol, preferably wherein the molar ratio is about 5:1 to 1:20; e) a mixture of choline chloride and glycerol, preferably wherein the molar ratio is about 5:1 to 1:20; f) a mixture of choline chloride and acetic acid, preferably wherein the molar ratio is about 5:1 to 1:10; g) a mixture of choline chloride and malonic acid, preferably wherein the molar ratio is about 4:1 to 1:6; h) a mixture of oxalic acid and choline chloride, preferably wherein the molar ratio is about 2:1 to 1:2, preferably about 1:1; i) a mixture of choline chloride and glucose, preferably wherein the molar ratio is about 6:1 to 1:6; j) a mixture of choline chloride and fructose, preferably wherein the molar ratio is about 6:1 to 1:6; k) a mixture of choline chloride and xylitol, preferably wherein the molar ratio about 6:1 to 1:6; l) a mixture of choline chloride and erythritol, preferably wherein the molar ratio is about 6:1 to 1:6; m) a mixture of lithium chloride and ethylene glycol, preferably wherein the molar ratio is about 4:1 to 1:4 n) a mixture of sodium chloride and ethylene glycol, preferably wherein the molar ratio is about 4:1 to 1:4; o) a mixture of lithium chloride and water, preferably wherein the molar ratio is about 4:1 to 1:4; p) a mixture of aluminium trichloride and acetamide, preferably wherein the molar ratio is about 4:1 to 1:4; q) a mixture of aluminium trichloride and urea, preferably wherein the molar ratio is about 4:1 to 1:4; or r) a mixture of tin chloride dihydrate and ethylene glycol, preferably wherein the molar ratio is about 4:1 to 1:4.

10 . The method of claim 1 , wherein the deep eutectic solvent comprises oxalic acid and choline chloride or ethylene glycol and choline chloride, optionally oxalic acid and choline chloride in a molar ratio of about 1:1 or ethylene glycol and choline chloride in a molar ratio of about 2:1.

11 . The method of claim 1 , wherein the deep eutectic solvent is a natural deep eutectic solvent comprising: an acid and quaternary ammonium salt; an acid and betaine; an acid and an acid; an acid and an amino acid; an acid and a sugar; a combination of any of these, wherein the acid, amino acid, sugar and quaternary ammonium salt are selected from any of those set out in Table 1.

12 . The method of claim 1 , wherein the deep eutectic solvent is a natural deep eutectic solvent comprising any of the components indicated in Table 1.

13 . The method of claim 1 wherein the lead-based material is a de-sulfurised lead-based material.

14 . The method of claim 1 , wherein the lead-based material comprises Pb, PbO, PbO 2 , PbCO 3 , or (PbCO 3 ) 2 .Pb(OH) 2 , or a mixture thereof.

15 . The method of claim 1 , wherein a concentration of lead- and/or tin-based material of about 1 gL −1 to about 100 gL −1 is dissolved in the deep eutectic solvent.

16 . The method of claim 1 , wherein a concentration of lead- and/or tin-based material of about 0.005 mol L −1 to about 0.5 mol L −1 is dissolved in the deep eutectic solvent.

17 . The method of claim 1 , further comprising the step of filtering the precipitated lead and/or tin carboxylate.

18 . The method of claim 17 , further comprising the step of heating the lead carboxylate to form leady oxide, optionally wherein the lead carboxylate is heated to at least about 300° C., preferably at least about 350° C.

19 . The method of claim 1 , wherein the method is a batch process.

20 . The method of claim 1 , wherein the method is a continuous process.

Assignees

• Imperial College Innovations Ltd

Inventors

• Hekselman Aleksandra Katarzyna
• Payne David
• Wang Yanying
• Ballantyne Andrew

Classifications

• C22B7/006

  Wet processes · CPC title

• C22B25/06

  from scrap, especially tin scrap (by electrolytic procedure C25C1/14) · CPC title

• C22B13/045 Primary

  Recovery from waste materials · CPC title

• C01G21/02 Primary

  Oxides · CPC title

• C22B3/44

  by chemical processes (treatment or purification of solutions by liquid-liquid extraction C22B3/26, by ion-exchange extraction C22B3/42) · CPC title