Inhibition of the depletion of metal values from pregnant lixiviant solutions

Abstract

Methods for inhibiting depletion of mineral values from pregnant lixiviant solutions comprise contacting the requisite metal ore with a preg-robbing inhibition agent (PRIA) comprising (I) alkyl polyglucoside surfactants; (II) imidazoline based amphoteric surfactants; and (III) hydroformylation products of lower (C 2 -C 8 ) alkanes in an organic solvent medium.

What is claimed is:  
     
         1 . In the leaching of metals from a metal ore in which a lixiviant solution is placed in contact with said metal ore to extract said metal therefrom in the form of a pregnant lixiviant solution, a method of inhibiting depletion of said extracted metal from said pregnant lixiviant solution, said method comprising contacting said metal ore with an effective amount of a preg-robbing inhibition agent (PRIA) comprising a member selected from the groups consisting of I, II, and III and mixtures of said groups wherein I is an alkyl polyglucoside surfactant, II is an imidazoline based amphoteric surfactant, and III comprises hydroformylation products of C 2 -C 8  alkenes in a C 3 -C 24  medium.  
     
     
         2 . Method as recited in  claim 1  wherein from about 0.024-about 6 kg of said PRIA is brought into contact with said metal ore based upon 1 ton of said metal ore.  
     
     
         3 . Method as recited in  claim 2  wherein from about 0.5-about 2.0 kg of said PRIA is brought into contact with said metal ore based upon 1 ton of said metal ore.  
     
     
         4 . Method as recited in  claim 1  wherein said metal ore comprises a precious metal.  
     
     
         5 . Method as recited in  claim 4  wherein said precious metal ore comprises gold.  
     
     
         6 . Method as recited in  claim 5  wherein said pregnant lixiviant solution comprises a cyanide solution.  
     
     
         7 . Method as recited in  claim 1  wherein I is present and comprises an alkyl group of about 4-20 carbon atoms and about 1-4 glucose units.  
     
     
         8 . Method as recited in  claim 7  wherein in I, said alkyl group has from about 8 to about 16 carbon atoms.  
     
     
         9 . Method as recited in  claim 1  wherein II is present and said amphoteric imidazoline surfactant comprises i) an amphopropionate compound; ii) an amphodipropionate compound; iii) an amphoacetate compound; or iv) an amphodiacetate compound.  
     
     
         10 . Method as recited in  claim 9  wherein said amphoteric imidazoline surfactant comprises disodium capryloamphodiacetate.  
     
     
         11 . Method as recited in  claim 10  wherein said amphoteric imidazoline surfactant comprises disodium cocoamphodipropionate.  
     
     
         12 . Method as recited in  claim 1  wherein III is present and said C 1 -C 8  alkene hydroformylation products comprise 2-ethylhexanol, 2-methylpentanol, 2-ethylhexanal; 2-methylhexanol in a medium containing C 3 -C 24  alcohols, aldehydes and esters.  
     
     
         13 . Method as recited in  claim 1  wherein said preg-robbing inhibition agent further comprises kerosene.  
     
     
         14 . In a metal pulp comprising a gold metal ore and a pregnant lixiviant solution containing gold cyanide complexes, a method of inhibiting adsorption of said gold cyanide complexes by said gold metal ore comprising contacting said gold metal ore with an effective preg-robbing inhibition agent (PRIA) comprising a member selected from the groups consisting of I, II, and III and mixtures of said groups wherein I is an alkyl polyglucoside surfactant, II is an imidazoline based amphoteric surfactant, and III comprises hydroformylation products of C 2 -C 8  alkenes in a C 3 -C 24  medium.  
     
     
         15 . Method as recited in  claim 14  wherein from about 0.024-about 6 kg of said PRIA is brought into contact with said gold metal ore based upon 1 ton of said gold metal ore.  
     
     
         16 . Method as recited in  claim 15  wherein from about 0.5kg -about 2 kg of said PRIA is brought into contact with said gold metal ore based upon 1 ton of said gold metal ore.  
     
     
         17 . Method as recited in  claim 14  wherein I is present and comprises an alkyl group of about 4-20 carbon atoms and about 1-4 glucose units.  
     
     
         18 . Method as recited in  claim 17  wherein in I, said alkyl group has from about 8 to about 16 carbon atoms.  
     
     
         19 . Method as recited in  claim 14  wherein II is present and said amphoteric imidazoline surfactant comprises i) an amphopropionate compound; ii) an amphodipropionate compound; iii) an amphoacetate compound; or iv) an amphodiacetate compound.  
     
     
         20 . Method as recited in  claim 19  wherein said amphoteric imidazoline surfactant comprises disodium capryloamphodiacetate.  
     
     
         21 . Method as recited in  claim 20  wherein said amphoteric imidazoline surfactant comprises disodium cocoamphodipropionate.  
     
     
         22 . Method as recited in  claim 14  wherein III is present and said hydroformylation products comprise 2-ethylhexanol, 2-methylpentanol, 2-ethyhexanal; 2-methylhexanol in a medium containing C 3 -C 24  alcohols, aldehydes and esters.  
     
     
         23 . Method as recited in  claim 14  wherein said preg-robbing inhibition agent further comprises kerosene.  
     
     
         24 . In a gold extraction process in which a lixiviant solution is brought into contact with a gold bearing ore to form a pregnant lixiviant solution, and wherein said pregnant lixiviant solution is contacted with activated carbon to aid in separating said gold from said pregnant lixiviant solution, the improvement comprising contacting said activated carbon with a member selected form the groups consisting of I, II, and III and mixtures of said groups wherein I is an alkyl polyglucoside surfactant, II is an imidazoline based amphoteric surfactant, and III comprises hydroformylation products of C 2 -C 8  alkenes in a C 3 -C 24  medium.