Removal of lead from solid materials

Abstract

A leaching composition that substantially removes lead from solid materials and a method of using said composition. Preferably, the concentration of lead in the solid materials following processing is low enough that the solid materials can be reused and/or disposed of at minimal cost to the processor. Preferably, the solid materials comprise glass, such as cathode ray tube glass.

1 . A method of leaching lead or other heavy metals from solid materials, said method comprising:
 pulverizing the solid materials to size in a range from about 10 microns to about 3 mm;   introducing the pulverized solid materials into a chemical processing vessel comprising a leaching composition to form a slurry;   agitating the slurry to leach the lead or other heavy metals from the solid material into the leaching composition,   wherein the leaching composition comprises at least one oxidant, at least one solvent, optionally at least one metal chelator, optionally at least one accelerator/NO x  (nitrogen oxide) suppressor, and optionally at least one etchant.   
     
     
         2 . The method of  claim 1 , wherein the solid material comprises cathode ray tube glass, soil, paint chips, electronic waste, and solder sludge. 
     
     
         3 . The method of  claim 1 , wherein the agitation occurs in the presence of added heat. 
     
     
         4 . The method of  claim 1 , further comprising filtering the solid material from the leaching composition. 
     
     
         5 . The method of  claim 4 , further comprising rinsing the solid material with a rinse composition to remove residual leaching composition therefrom. 
     
     
         6 . The method of  claim 4 , further comprising processing the leaching composition to recapture the lead or other heavy metals. 
     
     
         7 . The method of  claim 1 , wherein the material comprises glass and wherein the lead or other heavy metals on the surface of the pulverized solid material have been substantially removed. 
     
     
         8 . The method of  claim 1 , wherein the at least one oxidant comprises ozone, nitric acid, bubbled air, cyclohexylaminosulfonic acid, hydrogen peroxide, oxone, ammonium peroxomonosulfate, ammonium chlorite, ammonium chlorate, ammonium iodate, ammonium perborate, ammonium perchlorate, ammonium periodate, ammonium persulfate, ammonium hypochlorite, sodium persulfate, sodium hypochlorite, potassium iodate, potassium permanganate, potassium persulfate, potassium persulfate, potassium hypochlorite, tetramethylammonium chlorite, tetramethylammonium chlorate, tetramethylammonium iodate, tetramethylammonium perborate, tetramethylammonium perchlorate, tetramethylammonium periodate, tetramethylammonium persulfate, tetrabutylammonium peroxomonosulfate, peroxomonosulfuric acid, urea hydrogen peroxide, peracetic acid, sodium nitrate, potassium nitrate, ammonium nitrate, sulfuric acid, methanesulfonic acid (MSA), ethanesulfonic acid, 2-hydroxyethanesulfonic acid, n-propanesulfonic acid, isopropanesulfonic acid, isobutenesulfonic acid, n-butanesulfonic acid, and n-octanesulfonic acid, and combinations thereof. 
     
     
         9 . The method of  claim 1 , wherein the at least one oxidant comprises methanesulfonic acid, nitric acid, or a combination of methanesulfonic acid and nitric acid. 
     
     
         10 . The method of  claim 1 , wherein the leaching composition comprises the at least one metal chelator, wherein the at least one metal chelator 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), (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, 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, sodium chloride, lithium chloride, potassium chloride, ammonium sulfate, hydrochloric acid, sulfuric acid, and combinations thereof. 
     
     
         11 . The method of  claim 1 , wherein the leaching composition comprises the at least one metal chelator, wherein the at least one metal chelator comprises ammonium chloride, sodium chloride, lithium chloride, potassium chloride, ammonium sulfate, hydrochloric acid, sulfuric acid, and combinations thereof. 
     
     
         12 . The method of  claim 1 , wherein the leaching composition comprises the at least one accelerator/NO x  (nitrogen oxide) suppressor, wherein the at least one accelerator/NO x  suppressor comprises a species selected from the group consisting of ascorbic acid, adenosine, L(+)-ascorbic acid, isoascorbic acid, ascorbic acid derivatives, citric acid, ethylenediamine, gallic acid, oxalic acid, tannic acid, ethylenediaminetetraacetic acid (EDTA), uric acid, 1,2,4-triazole (TAZ), benzotriazole (BTA), tolyltriazole, 5-phenyl-benzotriazole, 5-nitro-benzotriazole, 3-amino-5-mercapto-1,2,4-triazole, 1-amino-1,2,4-triazole, hydroxybenzotriazole, 2-(5-amino-pentyl)-benzotriazole, 1 -amino-1,2,3 -triazol e, 1 -amino-5-methyl-1,2,3-triazol e, 3-amino-1,2,4-triazole, 3-mercapto-1,2,4-triazole, 3-isopropyl-1,2,4-triazole, 5-phenylthiol-benzotriazole, halo-benzotriazoles (halo=F, Cl, Br or I), naphthotriazole), 4-amino-1,2,4-triazole (ATAZ), 2-mercaptobenzimidazole (MBI), 2-mercaptobenzothiazole, 4-methyl-2-phenylimidazole, 2-mercaptothiazoline, 5-aminotetrazole (ATA), 5-amino-1,3,4-thiadiazole-2-thiol, 2,4-diamino-6-methyl-1,3,5-triazine, thiazole, triazine, methyltetrazole, 1,3-dimethyl-2-imidazolidinone, 1,5-pentamethylenetetrazole, 1-phenyl-5-mercaptotetrazole, diaminomethyltriazine, imidazoline thione, mercaptobenzimidazole, 4-methyl-4H-1,2,4-triazole-3-thiol, 5-amino-1,3,4-thiadiazole-2-thiol, benzothiazole, tritolyl phosphate, imidazole, indiazole, benzoic acid, boric acid, malonic acid, ammonium benzoate, catechol, pyrogallol, resorcinol, hydroquinone, cyanuric acid, barbituric acid, 1,2-dimethylbarbituric acid, pyruvic acid, adenine, purine, phosphonic acid and derivatives thereof, glycine/ascorbic acid, Dequest 2000, Dequest 7000, p-tolylthiourea, succinic acid, phosphonobutane tricarboxylic acid (PBTCA), sodium molybdate, ammonium molybdate, salts of chromate (e.g., sodium, potassium, calcium, barium), sodium tungstate, salts of dichromate (e.g., sodium, potassium, ammonium), suberic acid, azaleic acid, sebacic acid, adipic acid, octamethylene dicarboxylic acid, pimelic acid, dodecane dicarboxylic acid, dimethyl malonic acid, 3,3-diethyl succinic acid, 2,2-dimethyl glutaric acid, 2-methyl adipic acid, trimethyl adipic acid, 1,3-cyclopentane dicarboxylic acid, 1,4-cyclohexane dicarboxylic acid, terephthalic acid, isophthalic acid, 2,6-naphthalene dicarboxylic acid, 2,7-naphthalene dicaroxylic acid, 1,4-naphthalene dicarboxylic acid, 1,4-phenylenedioxy diacetic acid, 1,3-phenylenedioxy diacetic acid, diphenic acid, 4,4′-biphenyl dicarboxylic acid, 4,4′-oxydibenzoic acid, diphenylmethane-4,4′-dicarboxylic acid, diphenylsulfone-4,4′-dicarboxylic acid, decamethylene dicarboxylic acid, undecamethylene dicarboxylic acid, dodecamethylene dicarboxylic acid, orthophthalic acid, naphthalenedicarboxylic acid, paraphenylenedicarboxylic acid, trimellitic acid, pyromellitic acid, sodium hexametaphosphate, sodium silicates, 1-arginine, adensosine, adenine, and combinations thereof. 
     
     
         13 . The method of  claim 1 , wherein the leaching composition comprises the at least one accelerator/NO x  (nitrogen oxide) suppressor, wherein the at least one accelerator/NO x  suppressor comprises ATAZ, TAZ, triazole derivatives, or combinations thereof. 
     
     
         14 . The method of  claim 1 , wherein the solvent comprises water. 
     
     
         15 . The method of  claim 1 , wherein the leaching composition comprises the at least one etchant, wherein the at least one etchant is selected from the group consisting of at least one carbonate species, at least one hydroxide species, at least one fluoride species, and any combination thereof. 
     
     
         16 . The method of  claim 15 , wherein the at least one etchant comprises a species selected from the group consisting of sodium carbonate; potassium carbonate; sodium hydrogen carbonate; LiOH; NaOH; KOH; RbOH; CsOH; Mg(OH) 2 ; Ca(OH) 2 ; Sr(OH) 2 ; Ba(OH) 2 ; NR 4 OH, wherein R can be the same as or different from one another and include H, C 1 -C 6  alkyl, C 6 -C 10  aryl, and combinations thereof; xenon difluoride; HF; pentamethyldiethylenetriammonium trifluoride;
 ammonium bifluoride; triethylaminogallate trihydrofluoride; alkyl hydrogen fluoride (NRH 3 F), wherein each R is independently selected from hydrogen and C 1 -C 4  alkyl; dialkylammonium hydrogen fluoride (NR 2 H 2 F), wherein each R is independently selected from hydrogen and C 1 -C 4  alkyl; trialkylammonium hydrogen fluoride (NR 3 HF), wherein each R is independently selected from hydrogen and C 1 -C 4  alkyl; trialkylammonium trihydrogen fluoride (NR 3 :3HF), wherein each R is independently selected from hydrogen and C 1 -C 4  alkyl; ammonium fluorides of the formula R 4 NF, wherein each R is independently selected from hydrogen, C 1 -C 4  alkyl, and C 1 -C 4  alkanol; and combinations thereof.