Sulfide treatment to inhibit mercury adsorption onto activated carbon in carbon-in-pulp gold recovery circuits
OwnerFreddie J. Touro, Delbert A. Lippsinventors
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Abstract
In this invention sulfide compounds are added to mercury and precious metal-containing carbonaceous ore slurries prior to the slurry being processed by a carbon-in-pulp system. The sulfide compound inhibits the mercury from being adsorbed onto the activated carbon by reacting with the mercury to form mercuric sulfide and by inhibiting the dissolution of mercury from the ore. The mercuric sulfide precipitate displays no activity toward the activated carbon. The sulfiding procedure is performed with a sufficient amount of sulfide-providing compound to provide at least about 30 times the stoichiometric amount of sulfide ions required to react with the mercury in the ore slurry.
Claims22
A process for treating a mercury-contaminated, precious metal-containing ore slurry comprising:
- (a) reacting sulfide anions in an aqueous ore slurry of a mercury and precious metal-containing carbonaceous ore, said sulfide anions being added in an amount equal to at least about 30 times the stoichiometric amount required to react with said mercury contained in said ore slurry and being provided by a sulfide compound that is a member selected from the group consisting of sodium sulfide, sodium hydrosulfide, and hydrogen sulfide;
- and
- (b) conducting a simultaneous cyanide leach and carbon-in-pulp adsorption of said precious metal from said carbonaceous ore in said sulfide-containing ore slurry.
A process for treating a mercury-contaminated, precious metal-containing ore slurry comprising:
- (a) grinding a mercury and precious metal-containing carbonaceous ore with water to form an aqueous ore slurry;
- (b) oxidizing said aqueous ore slurry wherein said ore slurry is oxidized by hypochlorite ions;
- (c) eliminating residual hypochlorite ions in said aqueous ore slurry;
- (d) reacting sulfide anions in said oxidized ore slurry, said sulfide anions being in an amount at least about 30 times the stoichiometric amount required to react with said mercury contained in said aqueous ore slurry and being provided by a sulfide compound that is a member selected from the group consisting of sodium sulfide, sodium hydrosulfide, and hydrogen sulfide;
- and
- (e) conducting a simultaneous cyanide leach and carbon-in-pulp adsorption of said precious metal from said carbonaceous ore in said sulfide-containing ore slurry.
A process for treating a mercury-contaminated, precious metal-containing ore slurry comprising:
- (a) conducting a cyanide leach of an aqueous ore slurry of a mercury and precious metal-containing ore;
- (b) reacting sulfide anions in said aqueous ore slurry, said sulfide anions being added in an amount equal to at least about 30 times the stoichiometric amount required to react with said mercury contained in said ore slurry and being provided by a sulfide compound that is a member selected from the group consisting of sodium sulfide, sodium hydrosulfide, and hydrogen sulfide;
- and
- (c) conducting a carbon-in-pulp adsorption of said precious metal from said carbonaceous ore in said sulfide-containing ore slurry.
A process for treating a mercury-contaminated, precious metal-containing ore slurry comprising:
- (a) grinding a mercury and precious metal-containing carbonaceous ore with water to form an aqueous ore slurry;
- (b) oxidizing said aqueous ore slurry wherein said ore slurry is oxidized by hypochlorite ions;
- (c) eliminating residual hypochlorite ions in said aqueous ore slurry;
- (d) conducting a cyanide leach of said aqueous ore slurry;
- (e) reacting sulfide anions in said leached ore slurry, said sulfide anions being in an amount at least about 30 times the stoichiometric amount required to react with said mercury contained in said aqueous ore slurry and being provided by a sulfide compound that is a member selected from the group consisting of sodium sulfide, sodium hydrosulfide, and hydrogen sulfide;
- and
- (f) conducting a carbon-in-pulp adsorption of said precious metal from said carbonaceous ore in said sulfide-containing ore slurry.
Dependencies are inferred from the claim text.