Metal recovery process

Claim 2

A process for the recovery of a metal selected from the group consisting of copper and lead from its respective sulfide ore, said process being performed under conditions resulting in substantially reduced emission of environmental pollutants, comprising: (a) providing a reaction zone; (b) introducing said sulfide ore containing from about 20 to 85 wt % of the selected metal, a carbonaceous material, an alkali metal carbonate and gaseous oxygen into said reaction zone to form a molten reaction mixture, said alkali metal carbonate and sulfide ore being introduced in amounts to provide a molar ratio of carbonate to metal sulfide of at least 1.2:1; (c) said carbonaceous material being introduced in an amount sufficient to reduce substantially all of the selected metal sulfide to the elemental form of the metal and in a sufficient excess os that there is generated in situ substantially all the heat required to maintain the reaction zone at a selected temperature between 600° and 1350° C; (d) maintaining the reaction zone at said selected temperature for a time sufficient for a reaction to occur in the mixture between the selected metal sulfide, the carbonaceous material and the alkali metal carbonate to form a desired amount of the selected metal in its elemental form in the molten state in a single stage, said molten metal settling to the bottom of the reaction zone; and (e) withdrawing the formed molten metal from the reaction zone as a flowable liquid substantially free of impurities.

Claim 3

The process of claim 1 wherein the selected metal is copper.

Claim 4

The process of claim 1 wherein the selected metal is lead.

Claim 5

The process of claim 2 wherein the reaction zone is maintained at a temperature within the range of from about 1100° to 1350° C.

Claim 6

The process of claim 3 wherein the reaction zone is maintained at a temperature within the range of from about 850° to 1000° C.

Claim 7

The process of claim 1 wherein a side stream of the molten reaction mixture is withdrawn, quenched with and dissolved in an aqueous solution, and said solution is contacted with carbon dioxide to reform alkali metal carbonate for return to the reaction zone.

Claim 8

The process of claim 6 wherein a gaseous reaction product is obtained from the reaction zone and comprises the source of carbon dioxide for use in the reformation of the carbonate.

Claim 9

A process for the recovery of a metal selected from the group consisting of copper and lead from its respective sulfide ore, said process being performed under conditions resulting in substantially reduced emission of environmental pollutants, comprising: (a) providing a reaction zone; (b) introducing said sulfide ore containing from about 20 to 85 wt % of the selected metal, a carbonaceous material, an alkali metal carbonate and gaseous oxygen into said reaction zone to form a molten reaction mixture, said alkali metal carbonate and sulfide ore being introduced in amounts to provide a molar ratio of carbonate to metal sulfide of at least 1.2:1; (c) said carbonaceous material being introduced in an amount sufficient to reduce substantially all of the selected metal sulfide to the elemental form of the metal and in a sufficient excess so that there is generated in situ substantially all the heat required to maintain the reaction zone at a selected temperature between 600° and 1350° C.; (d) maintaining the reaction zone at said selected temperature for a time sufficient for a reaction to occur in the reaction mixture between the selected metal sulfide, the carbonaceous material and the alkali metal carbonate to form a desired amount of the selected metal in its elemental form in the molten state in a single stage, said molten metal settling to the bottom of the reaction zone; (e) withdrawing the formed molten metal from the reaction zone as a flowable liquid subtantially free of impurities; and (f) withdrawing a side stream of the molten reaction mixture for regeneration of alkali metal sulfide contained therein to reform alkali metal carbonate for return to the reaction zone.

Claim 10

A process for the recovery of a metal selected from the group consisting of copper and lead from its respective sulfide ore, said process being performed under conditions resulting in substantially reduced emission of environmental pollutants, comprising: (a) providing a reaction zone; (b) introducing said sulfide ore containing from about 20 to 85 wt % of the selected metal, a carbonaceous material, an alkali metal carbonate and gaseous oxygen into said reaction zone to form a molten reaction mixture, said alkali metal carbonate and sulfide ore being introduced in amounts to provide a molar ratio of carbonate to metal sulfide of at least 1.2:1; (c) said carbonaceous material being introduced in an amount sufficient to reduce substantially all of the selected metal sulfide to the elemental form of the metal and in a sufficient excess so that there is generated in situ substantially all the heat required to maintain the reaction zone at a selected temperature between 600° and 1350° C.; (d) maintaining the reaction zone at said selected temperature for a time sufficient for a reaction to occur in the reaction mixture between the selected metal sulfide, the carbonaceous material and the alkali metal carbonate to form a desired amount of the selected metal in its elemental form in the molten state in a single stage, said molten metal settling to the bottom of the reaction zone; (e) withdrawing the formed molten metal from the reaction zone as a flowable liquid subtantially free of impurities; and (f) withdrawing a side stream of the molten reaction mixture for regeneration of alkali metal sulfide contained therein to reform alkali metal carbonate for return to the reaction zone.

Claim 11

The process of claim 8 wherein the seleted metal is copper and the reaction zone is maintained at a temperature within the range of from about 1100° to 1350° C.

Claim 12

The process of claim 8 wherein the selected metal is lead and the reaction zone is maintained at a temperature within the range of from about 850° to 1000° C.

Claim 13

The process of claim 8 wherein the molten carbonate stream withdrawn in step (f) is quenched with a dissolved in an aqueous solution, and said solution is contacted with a gaseous reaction product produced in the reaction zone to release sulfur constitutents and reform alkali metal carbonate for return to the reaction zone.