Method for recycling of obsolete printed circuit boards

Patent metadata

Field	Value
Publication number	US-2017079146-A1
Application number	US-201615341626-A
Country	US
Kind code	A1
Filing date	Nov 2, 2016
Priority date	Apr 15, 2010
Publication date	Mar 16, 2017
Grant date	—

Abstract

Processes for recycling printed wire boards using environmentally-friendly compositions, wherein electronic components, precious metals and base metals may be collected for reuse and recycling.

First claim

1 .- 38 . (canceled)

39 . A method of recovering at least one precious metal from a printed wire board (PWB) comprising solder and at least one precious metal, said method comprising:
(a) contacting a surface of the PWB with a first composition, wherein the PWB and the first composition are in a first vessel; (b) agitating said first vessel; (c) dissolving or solubilizing the solder in the first composition, wherein the first composition selectively removes the solder relative to the at least one precious metal; (d) removing the first composition from the PWB by rinsing; (e) drying the PWB; (f) contacting the PWB with a leaching composition, wherein the PWB and the leaching composition are in a second vessel; (g) producing agitation in said second vessel; (h) dissolving or solubilizing the at least one precious metal in the leaching composition; (i) removing the leaching composition from the PWB by rinsing; and (j) recovering the at least one precious metal from the leaching composition, wherein the first composition is: (i) substantially devoid of fluoride salts, ferric nitrate and other ferric salts, titanium (IV) salts, and abrasive material; (ii) substantially devoid of fluoride salts, ferric nitrate and other ferric salts, titanium (IV) salts, and fluoroboric acid; (iii) substantially devoid of fluoride salts, ferric nitrate and other ferric salts, abrasive material, and fluoroboric acid; (iv) substantially devoid of fluoride salts, titanium (IV) salts, abrasive material, and fluoroboric acid; (v) substantially devoid of ferric nitrate and other ferric salts, titanium (IV) salts, abrasive material, and fluoroboric acid; or (vi) substantially devoid of fluoride salts, ferric nitrate and other ferric salts, titanium (IV) salts, abrasive material, and fluoroboric acid.

40 . The method of claim 39 , wherein at least one component is attached to a surface of the PWB, wherein the at least one component is selected from the group consisting of transistors, capacitors, heat sinks, integrated circuits, resistors, integrated switches, chips, processors, and combinations thereof.

41 . The method of claim 40 , wherein the at least one component is attached to the surface of the PWB by solder, and wherein the dissolving or solubilizing of the solder in the first composition results in the separation of the at least one component from the PWB.

42 . The method of claim 39 , wherein the solder comprises lead, tin or a lead/tin alloy.

43 . The method of claim 39 , wherein the first composition comprises at least one oxidizing agent, nitric acid, and at least one passivating agent, wherein the at least one passivating agent 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), 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-triazole, 1-amino-5-methyl-1,2,3-triazole, 3-amino-1,2,4-triazole, 3-mercapto-1,2,4-triazole, 3-isopropyl-1,2,4-triazole, 5-phenylthiol-benzotriazole, halo-benzotriazoles, naphthotriazole 2-mercaptobenzothiazole, 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, 1,5-pentamethylenetetrazole, 1-phenyl-5-mercaptotetrazole, diaminomethyltriazine, 4-methyl-4H-1,2,4-triazole-3-thiol, 5-amino-1,3,4-thiadiazole-2-thiol, benzothiazole, tritolyl phosphate, indiazole, benzoic acid, boric acid, malonic acid, ammonium benzoate, catechol, pyrogallol, resorcinol, hydroquinone, cyanuric acid, barbituric acid and derivatives such as 1,2-dimethylbarbituric acid, alpha-keto acids such as pyruvic acid, phosphonic acid and derivatives thereof, glycine/ascorbic acid, Dequest 2000, Dequest 7000, p-tolylthiourea, succinic acid, phosphonobutane tricarboxylic acid (PBTCA), sodium molybdate, ammonium molybdate, sodium chromate, potassium chromate, calcium chromate, barium chromate, sodium tungstate, sodium dichromate, potassium dichromate, ammonium dichromate, 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, and combinations thereof.

44 . The method of claim 39 , wherein the first composition comprises at least one oxidizing agent, nitric acid, and at least one passivating agent, wherein the at least one passivating agent comprises a triazole derivative selected from the group consisting of 1,2,4-triazole, benzotriazole, 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-triazole, 1-amino-5-methyl-1,2,3-triazole, 3-amino-1,2,4-triazole, 3-mercapto-1,2,4-triazole, 3-isopropyl-1,2,4-triazole, 5-phenylthiol-benzotriazole, halo-benzotriazoles, naphthotriazole, and 4-methyl-4H-1,2,4-triazole-3-thiol.

45 . The method of claim 43 , wherein the at least one oxidizing agent comprises ozone, 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, methanesulfonic acid (MSA), ethanesulfonic acid, 2-hydroxyethanesulfonic acid, n-propanesulfonic acid, isopropanesulfonic acid, isobutenesulfonic acid, n-butanesulfonic acid, n-octanesulfonic acid, benzenesulfonic acid, 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-trinitrobenzen

Assignees

• Advanced Tech Materials

Inventors

• BROSSEAU André
• Grigorenko Svitlana
• Jiang Ping
• Korzenski Michael B

Classifications

• C22B7/008

  by an alkaline or ammoniacal leaching · CPC title

• H05K2203/178

  Demolishing, e.g. recycling, reverse engineering, destroying for security purposes; Using biodegradable materials · CPC title

• C23F1/44

  Compositions for etching metallic material from a metallic material substrate of different composition · CPC title

• Y10T29/49815

  Disassembling · CPC title

• C22B11/046

  from manufactured products, e.g. from printed circuit boards, from photographic films, paper or baths · CPC title