Process for removing iron from an aqueous acid solution containing iron and copper

Claim 2

A PROCESS FOR REMOVING IONS FROM AN AQUEOUS ACID SOLUTION WITHOUT REMOVING COPPER IONS CONTAINED THEREIN COMPRISING THE STEPS OF: COMBINING ACTIVATED CARBON WITH SAID AQUEOUS ACID SOLUTION IN AN AMOUNT OF AT LEAST ABOUT 0.01% BY WEIGHT OF SAID SOLUTION; ADJUSTING THE PH OF SAID ACID SOLUTION TO A VALUE IN THE RANGE OF FROM ABOUT 2.0 TO ABOUT 2.5 SO THAT IRON IONS CONTANED IN SAID SOLUTION ARE HYDROLYZED AND PRECIPITATED BY COPPER IONS CONTAINED THEREIN REMAIN IN SAID SOLUTION; AND THEN SEPARATING THE PRECIPITATE FROM SAID SOLUTION.

Claim 3

The process of claim 1 wherein said activated carbon is combined with said acid solution in an amount in the range of from about 0.1 to about 2% by weight of said solution.

Claim 4

The process of claim 2 wherein the pH of said solution is adjusted by combining a base therewith selected from the group consisting of calcium carbonate, sodium carbonate and mixtures thereof.

Claim 5

A process of removing ferric ions from an aqueous sulfuric acid leach solution containing copper ions without removing the copper ions therefrom which comprises the steps of: combining activated carbon with said aqueous acid leach solution in an amount of at least about 0.01% by weight of said solution; combining a base with said aqueous acid leach solution to adjust the pH thereof to a value in the range of from about 2.0 to about 2.5 so that said ferric ions are hydrolyzed and precipitated but copper ions contained in said solution remain therein; and separating the precipitate from said solution.

Claim 6

A process of removing ferric ions from an aqueous sulfuric acid leach solution containing copper ions without removing the copper ions therefrom which comprises the steps of: combining activated carbon with said aqueous acid leach solution in an amount of at least about 0.01% by weight of said solution; combining a base with said aqueous acid leach solution to adjust the pH thereof to a value in the range of from about 2.0 to about 2.5 so that said ferric ions are hydrolyzed and precipitated but copper ions contained in said solution remain therein; and separating the precipitate from said solution.

Claim 7

The process of claim 4 wherein said activated carbon is combined with said sulfuric acid leach solution in an amount in the range of from about 0.1 to about 2% by weight of said solution.

Claim 8

The process of claim 5 wherein said base is calcium carbonate.

Claim 9

In a process for recovering copper from an aqueous sulfuric acid leach solution containing copper and iron sulfates wherein iron is removed from said solution by combining a base therewith in an amount which adjusts the pH of said solution to a value greater than 2.5 thereby causing said iron and a portion of said copper to be hydrolyzed and precipitated, separating the resulting precipitate from said solution and then subjecting said solution to an electrowinning process to recover copper values therefrom, the improvement which comprises: adjusting the pH of said solution to a value in the range of from about 2 to about 2.5 so that iron ions contained in said solution are hydrolyzed and precipitated but copper ions remain in said solution; and combining activated carbon with said solution in an amount of at least about 0.1% by weight of said solution so that the rate of hydrolysis of said iron ions is increased.

Claim 10

In a process for recovering copper from an aqueous sulfuric acid leach solution containing copper and iron sulfates wherein iron is removed from said solution by combining a base therewith in an amount which adjusts the pH of said solution to a value greater than 2.5 thereby causing said iron and a portion of said copper to be hydrolyzed and precipitated, separating the resulting precipitate from said solution and then subjecting said solution to an electrowinning process to recover copper values therefrom, the improvement which comprises: adjusting the pH of said solution to a value in the range of from about 2 to about 2.5 so that iron ions contained in said solution are hydrolyzed and precipitated but copper ions remain in said solution; and combining activated carbon with said solution in an amount of at least about 0.1% by weight of said solution so that the rate of hydrolysis of said iron ions is increased.

Claim 11

The process of claim 7 wherein said activated carbon is combined with said solution in an amount in the range of from about 0.1 to about 2% by weight of solution.

Claim 12

The process of claim 8 wherein said base is calcium carbonate.