Sustainable process for reclaiming precious metals and base metals from e-waste

Abstract

Processes for recycling electronic components removed from printed wire boards, whereby precious metals and base metals are extracted from the electronic components using environmentally friendly compositions. At least gold, silver and copper ions can be extracted from the electronic components and reduced to their respective metals using the processes and compositions described herein.

1 .- 30 . (canceled) 
     
     
         31 . A method of removing more than one metal from e-waste, said method comprising:
 (a) contacting the e-waste with a first metal digestion composition to form a first extraction liquid and a first extraction solid, wherein the first metal digestion composition comprises at least one oxidizing agent and at least one complexing agent;   (b) separating the first extraction solid from the first extraction liquid;   (c) contacting the first extraction solid with a second metal digestion composition to form a second extraction liquid and a second extraction solid, wherein the second metal digestion composition comprises at least one oxidizing agent and at least one complexing agent;   (d) separating the second extraction solid from the second extraction liquid, wherein the second extraction liquid comprises first metal ions; and   (e) contacting the first extraction liquid with an additive to separate second metal ions from third metal ions,   wherein the at least one oxidizing agent comprises methanesulfonic acid (MSA), ethanesulfonic acid, benzenesulfonic acid, 2-hydroxyethanesulfonic acid, cyclohexylaminosulfonic acid, n-propanesulfonic acid, n-butanesulfonic acid, or n-octanesulfonic acid, hydrogen peroxide (H 2 O 2 ), FeCl 3  (both hydrated and unhydrated), oxone (2KHSO 5 .KHSO 4 .K 2 SO 4 ), ammonium peroxomonosulfate, ammonium chlorite (NH 4 ClO 2 ), ammonium chlorate (NH 4 ClO 3 ), ammonium iodate (NH 4 IO 3 ), ammonium perborate (NH 4 BO 3 ), ammonium perchlorate (NH 4 ClO 4 ), ammonium periodate (NH 4 IO 3 ), ammonium persulfate ((NH 4 ) 2 S 2 O 8 ), ammonium hypochlorite (NH 4 ClO), sodium persulfate (Na 2 S 2 O 8 ), sodium hypochlorite (NaClO), potassium iodate (KIO 3 ), potassium permanganate (KMnO 4 ), potassium persulfate, nitric acid (HNO 3 ), potassium persulfate (K 2 S 2 O 8 ), potassium hypochlorite (KClO), tetramethylammonium chlorite ((N(CH 3 ) 4 )ClO 2 ), tetramethylammonium chlorate ((N(CH 3 ) 4 )ClO 3 ), tetramethylammonium iodate ((N(CH 3 ) 4 )IO 3 ), tetramethylammonium perborate ((N(CH 3 ) 4 )BO 3 ), tetramethylammonium perchlorate ((N(CH 3 ) 4 )ClO 4 ), tetramethylammonium periodate ((N(CH 3 ) 4 )IO 4 ), tetramethylammonium persulfate ((N(CH 3 ) 4 )S 2 O 8 ), tetrabutylammonium peroxomonosulfate, peroxomonosulfuric acid, ferric nitrate (Fe(NO 3 ) 3 ), urea hydrogen peroxide ((CO(NH 2 ) 2 )H 2 O 2 ), peracetic acid (CH 3 (CO)OOH), sodium nitrate, potassium nitrate, ammonium nitrate, 4-methoxybenzenesulfonic acid, 4-hydroxybenzenesulfonic acid, 4-aminobenzenesulfonic acid, 4-nitrobenzenesulfonic acid, toluenesulfonic acid, hexylbenzenesulfonic acid, heptylbenzenesulfonic acid, octylbenzenesulfonic acid, nonylbenzenesulfonic acid, decylbenzenesulfonic acid, undecylbenzenesulfonic acid, dodecylbenzenesulfonic acid, tridecylbenzenesulfonic acid, tetradecylbenzene sulfonic acid, hexadecylbenzene sulfonic acid, 3-nitrobenzenesulfonic acid, 2-nitrobenzenesulfonic acid, 2-nitronaphthalenesulfonic acid, 3-nitronaphthalenesulfonic acid, 2,3-dinitrobenzenesulfonic acid, 2,4-dinitrobenzenesulfonic acid, 2,5-dinitrobenzenesulfonic acid, 2,6-dinitrobenzenesulfonic acid, 3,5-dinitrobenzenesulfonic acid, 2,4,6-trinitrobenzenesulfonic acid, 3-aminobenzenesulfonic acid, 2-aminobenzenesulfonic acid, 2-aminonaphthalenesulfonic acid, 3-aminonaphthalenesulfonic acid, 2,3-diaminobenzenesulfonic acid, 2,4-diaminobenzenesulfonic acid, 2,5-diaminobenzenesulfonic acid, 2,6-diaminobenzenesulfonic acid, 3,5-diaminobenzenesulfonic acid, 2,4,6-triaminobenzenesulfonic acid, 3-hydroxybenzenesulfonic acid, 2-hydroxybenzenesulfonic acid, 2-hydroxynaphthalenesulfonic acid, 3-hydroxynaphthalenesulfonic acid, 2,3-dihydroxybenzenesulfonic acid, 2,4-dihydroxybenzenesulfonic acid, 2,5-dihydroxybenzenesulfonic acid, 2,6-dihydroxybenzenesulfonic acid, 3,5-dihydroxybenzenesulfonic acid, 2,3,4-trihydroxybenzenesulfonic acid, 2,3,5-trihydroxybenzenesulfonic acid, 2,3,6-trihydroxybenzenesulfonic acid, 2,4,5-trihydroxybenzenesulfonic acid, 2,4,6-trihydroxybenzenesulfonic acid, 3,4,5-trihydroxybenzenesulfonic acid, 2,3,4,5-tetrahydroxybenzenesulfonic acid, 2,3,4,6-tetrahydroxybenzenesulfonic acid, 2,3,5,6-tetrahydroxybenzenesulfonic acid, 2,4,5,6-tetrahydroxybenzenesulfonic acid, 3-methoxybenzenesulfonic acid, 2-methoxybenzenesulfonic acid, 2,3-dimethoxybenzenesulfonic acid, 2,4-dimethoxybenzenesulfonic acid, 2,5-dimethoxybenzenesulfonic acid, 2,6-dimethoxybenzenesulfonic acid, 3,5-dimethoxybenzenesulfonic acid, 2,4,6-trimethoxybenzenesulfonic acid, and combinations thereof.   
     
     
         32 . The method of  claim 31 , wherein the e-waste has been pulverized to powder, shredded, crushed to expose the metals, or a combination thereof. 
     
     
         33 . The method of  claim 31 , wherein the method is carried out at temperature in a range from 20° C. to 70° C. 
     
     
         34 . The method of  claim 31 , wherein (i) the first metal digestion composition is the same as the second metal digestion composition, or (ii) the first metal digestion composition is different than the second metal digestion composition. 
     
     
         35 . The method of  claim 31 , wherein the first metal digestion composition further comprises at least one catalyst, wherein the at least one catalyst comprises a glycol or a glycol ether selected from the group consisting of ethylene glycol, propylene glycol, butylene glycol, dipropylene glycol, diethylene glycol monomethyl ether, triethylene glycol monomethyl ether, diethylene glycol monoethyl ether, triethylene glycol monoethyl ether, ethylene glycol monopropyl ether, ethylene glycol monobutyl ether, diethylene glycol monobutyl ether (DEGBE), triethylene glycol monobutyl ether, ethylene glycol monohexyl ether, diethylene glycol monohexyl ether, ethylene glycol phenyl ether, propylene glycol methyl ether, dipropylene glycol methyl ether (DPGME), tripropylene glycol methyl ether, dipropylene glycol dimethyl ether, dipropylene glycol ethyl ether, propylene glycol n-propyl ether, dipropylene glycol n-propyl ether (DPGPE), tripropylene glycol n-propyl ether, propylene glycol n-butyl ether, dipropylene glycol n-butyl ether, tripropylene glycol n-butyl ether, propylene glycol phenyl ether, and combinations thereof. Most preferably, the catalyst comprises diethylene glycol monobutyl ether, propylene glycol, dipropylene glycol n-butyl ether, and combinations thereof. 
     
     
         36 . The method of  claim 31 , wherein the second metal digestion composition further comprises at least one catalyst, wherein the at least one catalyst comprises a glycol or a glycol ether selected from the group consisting of ethylene glycol, propylene glycol, butylene glycol, dipropylene glycol, diethylene glycol monomethyl ether, triethylene glycol monomethyl ether, diethylene glycol monoethyl ether, triethylene glycol monoethyl ether, ethylene glycol monopropyl ether, ethylene glycol monobutyl ether, diethylene glycol monobutyl ether (DEGBE), triethylene glycol monobutyl ether, ethylene glycol monohexyl ether, diethylene glycol monohexyl ether, ethylene glycol phenyl ether, propylene glycol methyl ether, dipropylene glycol methyl ether (DPGME), tripropylene glycol methyl ether, dipropylene glycol dimethyl ether, dipropylene glycol ethyl ether, propylene glycol n-propyl ether, dipropylene glycol n-propyl ether (DPGPE), tripropylene glycol n-propyl ether, propylene glycol n-butyl ether, dipropylene glycol n-butyl ether, tripropylene glycol n-butyl ether, propylene glycol phenyl ether, and combinations thereof. Most preferably, the catalyst comprises diethylene glycol monobutyl ether, propylene glycol, dipropylene glycol n-butyl ether, and combinations thereof. 
     
     
         37 . The method of  claim 31 , wherein the at least one complexing agent comprises a species selected from the group consisting of acetylacetonate, 1,1,1-trifluoro-2,4-pentanedione, 1,1,1,5,5,5-hexafluoro-2,4-pentanedione, formates, acetates, bis(trimethylsilylamide) tetramer, glycine, serine, proline, leucine, alanine, asparagine, aspartic acid, glutamine, valine, and lysine, citric acid, acetic acid, maleic acid, oxalic acid, malonic acid, succinic acid, phosphonic acid, hydroxyethylidene diphosphonic acid (HEDP), 1-hydroxyethane-1,1-diphosphonic acid, nitrilo-tris(methylenephosphonic acid), nitrilotriacetic acid, iminodiacetic acid, etidronic acid, ethylenediamine, ethylenediaminetetraacetic acid (EDTA), and (1,2-cyclohexylenedinitrilo)tetraacetic acid (CDTA), uric acid, tetraglyme, pentamethyldiethylenetriamine (PMDETA), 1,3,5-triazine-2,4,6-thithiol trisodium salt solution, 1,3,5-triazine-2,4,6-thithiol triammonium salt solution, sodium diethyldithiocarbamate, disubstituted dithiocarbamates (R 1 (CH 2 CH 2 O) 2 NR 2 CS 2 Na) with one alkyl group (R 2 =hexyl, octyl, deceyl or dodecyl) and one oligoether (R 1 (CH 2 CH 2 O) 2 , where R 1 =ethyl or butyl), ammonium sulfate, monoethanolamine (MEA), Dequest 2000, Dequest 2010, Dequest 2060s, diethylenetriamine pentaacetic acid, propylenediamine tetraacetic acid, 2-hydroxypyridine 1-oxide, ethylendiamine disuccinic acid (EDDS), N-(2-hydroxyethyl)iminodiacetic acid (HEIDA), sodium triphosphate penta basic, ammonium chloride, ammonium sulfate, hydrochloric acid, sulfuric acid, and combinations thereof. 
     
     
         38 . The method of  claim 31 , wherein the at least one chelating agent comprises hydrochloric acid or sulfuric acid. 
     
     
         39 . The method of  claim 31 , wherein the at least one oxidizing agent comprises nitric acid. 
     
     
         40 . The method of  claim 31 , wherein the first and second metal digestion compositions are devoid of cyanide-containing compounds. 
     
     
         41 . The method of  claim 31 , wherein the additive comprises a pH adjusting agent. 
     
     
         42 . The method of  claim 41 , wherein the pH adjusting agent comprises hydroxide ions. 
     
     
         43 . The method of  claim 31 , wherein the pH of the first metal digestion composition is adjusted to pH in a range from about 6 to about 12. 
     
     
         44 . The method of  claim 41 , wherein the second metal ions are contained in a liquid fraction and the third metal ions are contained in a solid fraction. 
     
     
         45 . The method of  claim 31 , further comprising reducing the first metal ions to a first solid metal. 
     
     
         46 . The method of  claim 31 , further comprising reducing the second metal ions to a second solid metal. 
     
     
         47 . The method of  claim 31 , further comprising reducing the third metal ions to a third solid metal. 
     
     
         48 . The method of  claim 31 , wherein the first metal is gold. 
     
     
         49 . The method of  claim 31 , wherein the second metal is silver. 
     
     
         50 . The method of  claim 31 , wherein the third metal is copper.