Compositions for electrowinning acid mist suppression

Abstract

A composition for suppressing generation of acid mist in an electrowinning process. The composition includes about 1.5% to about 20% (m/m) of a C2 to C6 organic acid, about 15% to about 35% (m/m) of a diphenyl oxide disulfonate or diphenyl oxide sulfonic acid compound; and about 20% to about 30% (m/m) of a plant root extract containing a triterpenoid saponin. Methods for preparing the composition and using the composition in an electrowinning process are also described.

1 . An aqueous composition for suppressing generation of acid mist in an electrowinning process, the composition comprising:
 about 1.5% to about 20% (m/m) of a C 2  to C 6  organic acid;   about 15% to about 35% (m/m) of a diphenyl oxide disulfonate or diphenyl oxide disulfonic acid compound; and   about 20% to about 30% (m/m) of a plant root extract containing a triterpenoid saponin.   
     
     
         2 . The composition of  claim 1 , wherein the triterpenoid saponin is present in the plant root extract in an amount between about 4% to about 15% (m/m). 
     
     
         3 . The composition of  claim 1 , wherein the organic acid and the triterpenoid saponin are provided in a mass ratio ranging from about 0.05 parts organic acid:1 part triterpenoid saponin to about 0.65 parts organic acid:1 part triterpenoid saponin. 
     
     
         4 . The composition of  claim 1 , wherein the C 2  to C 6  organic acid has at least one carboxylic acid group with a pK a  value of between about 3.8 to about 5.5. 
     
     
         5 . The composition of  claim 1 , wherein the C 2  to C 6  organic acid is a C 2  to C 4  organic acid. 
     
     
         6 . The composition of  claim 5 , wherein the C 2  to C 4  organic acid is selected from the group consisting of acetic acid, lactic acid, oxalic acid, malic acid, taratic acid, butanoic acid and propanoic acid. 
     
     
         7 . The composition of  claim 1 , wherein the diphenyl oxide disulfonate or diphenyl oxide disulfonic acid compound is an acid or salt form of the general structure of: 
       
         
           
           
               
               
           
         
         wherein R is a linear or branched C 6  to C 16  alkyl group. 
       
     
     
         8 . The composition of  claim 7 , wherein R is a linear or branched C 12  alkyl group. 
     
     
         9 . The composition of  claim 8 , wherein the compound is: 
       
         
           
           
               
               
           
         
       
     
     
         10 . The composition of  claim 1 , wherein the triterpenoid saponin is a pentacyclic triterpenoid saponin or a tetracyclic triterpenoid saponin. 
     
     
         11 . The composition of  claim 10 , wherein the pentacyclic triterpenoid saponin is an enoxolone, a hederagenin, a hopane, a lupane, a maslinic acid, an oleanane, an ursane, or a taraxasterane. 
     
     
         12 . The composition of  claim 11 , wherein the enoxolone is glycyrrhizin. 
     
     
         13 . The composition of  claim 11 , wherein the tetracyclic triterpenoid saponin is a saponin of  Quillaja saponaria.    
     
     
         14 . The composition of  claim 1 , having a viscosity of about 740 to about 880 CPS. 
     
     
         15 . A method for reducing generation of acid mist in an electrowinning process, the method comprising adding a composition as recited in  claim 1  to an electrowinning solution to provide a composition concentration of about 5 to about 30 ppm. 
     
     
         16 . A method for preparing a product for suppressing generation of acid mist in an electrowinning process, the method comprising:
 mixing an aqueous solution of a C 2  to C 6  organic acid with a diphenyl oxide disulfonate or diphenyl sulfonic acid compound to provide a first mixture;   adding a triterpenoid saponin to the first mixture with agitation to generate a second mixture having an initial viscosity of about 1500 CPS to about 1900 CPS at a temperature between about 30° C. to about 40° C.; and   cooling the second mixture to a temperature between about 20° C. to about 25° C., thereby reducing the viscosity of the second mixture to a range between about 740 CPS to about 880 CPS, thereby providing the product.   
     
     
         17 . The method of  claim 16 , wherein the first mixture is formed with about a 2:1 ratio of the diphenyl oxide sulfonate compound relative to the C 2  to C 6  organic acid. 
     
     
         18 . The method of  claim 16 , wherein the second mixture is formed with the organic acid and the triterpenoid saponin provided in a mass ratio ranging from about 0.05 parts organic acid:1 part triterpenoid saponin to about 0.65 parts organic acid:1 part triterpenoid saponin. 
     
     
         19 . The method of  claim 16 , wherein the C 2  to C 6  organic acid is a C 2  to C 4  organic acid. 
     
     
         20 . The method of  claim 19 , wherein the C 2  to C 4  organic acid is selected from the group consisting of acetic acid, lactic acid, oxalic acid, malic acid, taratic acid, butanoic acid and propanoic acid. 
     
     
         21 . The method of  claim 16 , wherein the diphenyl oxide disulfonate or diphenyl oxide disulfonic acid compound is an acid or salt form of the general structure of: 
       
         
           
           
               
               
           
         
         wherein R=a linear or branched C 6  to C 16  alkyl group. 
       
     
     
         22 . The method of  claim 21 , wherein R=a linear or branched C 12  alkyl group. 
     
     
         23 . The method of  claim 22 , wherein the compound is: 
       
         
           
           
               
               
           
         
       
     
     
         24 . The method of  claim 16 , wherein the triterpenoid saponin is a pentacyclic triterpenoid saponin or a tetracyclic triterpenoid saponin. 
     
     
         25 . The method of  claim 24 , wherein the pentacyclic triterpenoid saponin is an enoxolone, a hederagenin, a hopane, a lupane, a maslinic acid, an oleanane, an ursane, or a taraxasterane. 
     
     
         26 . The method of  claim 25 , wherein the enoxolone is glycyrrhizin. 
     
     
         27 . The method of  claim 24 , wherein the tetracyclic triterpenoid saponin is a saponin of  Quillaja Saponaria.    
     
     
         28 . The method of  claim 16 , wherein the product has a viscosity of about 740 to about 880 CPS.