Use of Nonionic Surfactants in Extractive Metallurgy by Electrolysis

Abstract

A process for the electrolytic treatment of metal-containing solutions, wherein at least one nonionic surfactant is used in the electrolyte solution, the surfactant reducing the surface tension of the electrolyte solution at a surfactant concentration of 0.2% by weight and a temperature of 24° C. in an aqueous solution with 190 g/l of sulfuric acid and 157 g/l of copper sulfate, which is diluted with water in a ratio of 1:10, by from 20 to 60%, is useful for working up ores or the purification of metals, like copper, chromium, nickel, zinc, gold and silver.

1 - 24 . (canceled) 
     
     
         25 : A process for the electrolytic treatment of metal-containing solutions for separating substances, working up ores and/or purifying metals, wherein at least one nonionic surfactant is used in the electrolyte solution, said surfactant reducing the surface tension of the electrolyte solution at a surfactant concentration of 0.2% by weight and a temperature of 24° C. in an aqueous solution with 190 g/l of sulfuric acid and 157 g/l of copper sulfate, which is diluted with water in a ratio of 1:10, by from 20 to 60%, wherein said nonionic surfactant is selected from the group consisting of alkoxylated C 4 - to C 22 -alcohols, alkylpolyglucosides, N-alkylpolyglucosides, N-alkylglucamides, fatty acid alkoxylates, fatty acid polyglycol esters, fatty acid amine alkoxylates, optionally endcapped fatty acid amide alkoxylates, fatty acid alkanolamide alkoxylates, N-alkoxypolyhydroxy-fatty acid amides, N-aryloxypolyhydroxy-fatty acid amides, polyisobutene/maleic anhydride derivatives, fatty acid glycerides, sorbitan esters, polyhydroxy-fatty acid derivatives, polyalkoxy fatty acid derivatives and bisglycerides. 
     
     
         26 : The process according to  claim 25 , wherein said surfactant, after shaking twenty times in the course of 5 seconds, has a foam volume of at least 10 ml in a solution comprising 50 g of an aqueous solution with 190 g/l of sulfuric acid and 157 g/l of copper sulfate with 0.5% by weight of the surfactant, based on the solution. 
     
     
         27 : The process according to  claim 25 , wherein the electrolytic working-up is effected starting from an acidic aqueous solution of the metal as the electrolyte solution. 
     
     
         28 : The process according to  claim 27 , wherein the acidic aqueous solution of the metal is obtained by the following process steps:
 (a) obtaining a metal-containing mother liquor by leaching of the metal from a metal-containing starting material by the treatment thereof with acids or alkalis;   (b) transferring the metal to an organic phase by treatment of the metal-containing mother liquor with an organic phase which comprises an extracting or complexing agent suitable for the metal to be extracted; and   (c) transferring the metal to the acidic aqueous solution by treatment of the organic phase with an acidic aqueous solution.   
     
     
         29 : The process according to  claim 27 , wherein the acidic aqueous solution of the metal is selected from chromium- and copper-containing solutions which comprise sulfuric acid. 
     
     
         30 : The process according to  claim 25 , wherein said nonionic surfactant is an alkylpolyglucoside having 6 to 22 carbon atoms in the alkyl chain and 1 to 20 glucose units. 
     
     
         31 : The process according to  claim 25 , wherein said nonionic surfactant is a C 12-18 -fatty alcohol ethoxylate which has been reacted with from 2 to 80 ethylene oxide units. 
     
     
         32 : The process according to  claim 25 , wherein the concentration of the nonionic surfactant in the electrolyte solution is from 0.001 to 0.5% by weight, based on the solution. 
     
     
         33 : The process according to  claim 25 , wherein said nonionic surfactant additionally comprises one selected from the group consisting of block copolymers of ethylene oxide and propylene oxide, block copolymers of ethylene oxide, propylene oxide and butylene oxide, block copolymers blocked at one or both ends and comprising ethylene oxide and propylene oxide or ethylene oxide, propylene oxide and butylene oxide, and saponins. 
     
     
         34 : A method of using nonionic surfactants in electrolytic treatments of metal-containing solutions for separating substances, working up ores and/or purifying metals, wherein said surfactant reduces the surface tension of the electrolyte solution at a surfactant concentration of 0.2% by weight and a temperature of 24° C. in an aqueous solution with 190 g/l of sulfuric acid and 157 g/l of copper sulfate, which is diluted with water in a ratio of 1:10, by a value of from 20 to 60%, wherein said nonionic surfactant is selected from the group consisting of alkoxylated C 4 - to C 22 -alcohols, alkylpolyglucosides, N-alkylpolyglucosides, N-alkylglucamides, fatty acid alkoxylates, fatty acid polyglycol esters, fatty acid amine alkoxylates, fatty acid amide alkoxylates, fatty acid alkanolamide alkoxylates, N-alkoxypolyhydroxy-fatty acid amides, N-aryloxypolyhydroxy-fatty acid amides, polyisobutene alkoxylates, polyisobutene/maleic anhydride derivatives, fatty acid glycerides, sorbitan esters, polyhydroxy-fatty acid derivatives, polyalkoxy-fatty acid derivatives and bisglycerides. 
     
     
         35 : The method according to  claim 34 , wherein said surfactant after shaking twenty times for 5 seconds in each case has a foam volume of at least 10 ml in a solution comprising 50 g of an aqueous solution with 190 g/l of sulfuric acid and 157 g/l of copper sulfate with 0.5% by weight of the surfactant, based on the solution. 
     
     
         36 : The method according to  claim 34 , wherein said nonionic surfactant additionally comprises one selected from the group consisting of block copolymers of ethylene oxide and propylene oxide, block copolymers of ethylene oxide, propylene oxide and butylene oxide, block copolymers blocked at one or both ends and comprising ethylene oxide and propylene oxide or ethylene oxide, propylene oxide and butylene oxide, and saponins. 
     
     
         37 : A process for the electrolytic treatment of metal-containing solutions for separating substances, working up ores and/or purifying metals, wherein at least one nonionic surfactant is used in the electrolyte solution, said surfactant being selected from the group consisting of alkoxylated C 4 - to C 22 -alcohols, alkylpolyglucosides, N-alkyl-polyglucosides, N-alkylglucamides, fatty acid alkoxylates, fatty acid polyglycol esters, fatty acid amine alkoxylates, fatty acid amide alkoxylates, fatty acid alkanolamide alkoxylates, N-alkoxypolyhydroxy-fatty acid amides, N-aryloxypolyhydroxy-fatty acid amides, polyisobutene alkoxylates, polyisobutene/maleic acid anhydride derivatives, fatty acid glycerides, sorbitan esters, polyhydroxy-fatty acid derivatives, polyalkoxy-fatty acid derivatives and bisglycerides. 
     
     
         38 : The process according to  claim 37 , wherein said nonionic surfactant is an alkylpolyglucoside having 6 to 22 carbon atoms in the alkyl chain and 1 to 20 glucose units. 
     
     
         39 : The process according to  claim 37 , wherein said nonionic surfactant is a C 12-18 -fatty alcohol ethoxylate which has been reacted with from 2 to 80 ethylene oxide units. 
     
     
         40 : The process according to  claim 37 , wherein said nonionic surfactant additionally comprises one selected from the group consisting of block copolymers of ethylene oxide and propylene oxide, block copolymers of ethylene oxide, propylene oxide and butylene oxide, block copolymers blocked at one or both ends and comprising ethylene oxide and propylene oxide or ethylene oxide, propylene oxide and butylene oxide, and saponins. 
     
     
         41 : A method of using nonionic surfactants in electrolytic treatments of metal-containing solutions, wherein said nonionic surfactant is selected from the group consisting of alkoxylated C 4 - to C 22 -alcohols, alkylpolygluco sides, N-alkylpolyglucosides, N-alkylglucamides, fatty acid alkoxylates, fatty acid polyglycol esters, fatty acid amine alkoxylates, fatty acid amide alkoxylates, fatty acid alkanolamide alkoxylates, N-alkoxypolyhydroxy-fatty acid amides, N-aryloxypolyhydroxy-fatty acid amides, polyisobutene alkoxylates, polyisobutene/maleic anhydride derivatives, fatty acid glycerides, sorbitan esters, polyhydroxy-fatty acid derivatives, polyalkoxy-fatty acid derivatives and bisglycerides. 
     
     
         42 : The method according to  claim 41  wherein said nonionic surfactant is an alkylpolyglucoside having 6 to 22 carbon atoms in the alkyl chain and 1 to 20 glucose units. 
     
     
         43 : The method according to  claim 41 , wherein said nonionic surfactant comprises C 12-18 -fatty alcohol ethoxylates which have been reacted with from 2 to 80 ethylene oxide units. 
     
     
         44 : The method according to  claim 41 , wherein said nonionic surfactant additionally comprises one selected from the group consisting of block copolymers of ethylene oxide and propylene oxide, block copolymers of ethylene oxide, propylene oxide and butylene oxide, block copolymers blocked at one or both ends and comprising ethylene oxide and propylene oxide or ethylene oxide, propylene oxide and butylene oxide, and saponins. 
     
     
         45 : Process according to  claim 25 , wherein said surfactant reduces the surface tension by from 25 to 55%.