Smelting method

Abstract

A method of recovering gold from a gold containing source material comprising: forming a molten pool comprising at least one metal selected from the group consisting of copper, silver, gold and platinum group metals; and adding at least part of the source material into the molten pool of metal.

1 . A method of recovering gold from a gold-containing source material comprising:
 forming a molten pool comprising at least one collector metal selected from the group consisting of copper, silver, gold and platinum group metals; and   adding at least part of the source material into the molten pool of collector metal.   
     
     
         2 . A method according to  claim 1  wherein the collector metal comprises at least one selected from copper, and silver. 
     
     
         3 . A method according to  claim 1  wherein the source material and collector are each in particulate form and the method comprises forming the molten pool from a particulate mixture comprising particulate source material and particulate collector. 
     
     
         4 . A method according to  claim 1  wherein the source material comprises at least one of:
 a. cathode-associated material formed during electrolysis of a strip liquor; 
 b. anode-associated material formed during the electrolytic refining of copper or other base metal from a base metal cast anode; and 
 c. gravity gold. 
 
     
     
         5 . A method according to  claim 1  wherein the source material comprises a cathode-associated material formed during electrolysis of strip liquor. 
     
     
         6 . A method according to  claim 1  comprising forming an initial pool of molten collector metal and adding one or more charges of particulate source material. 
     
     
         7 . (canceled) 
     
     
         8 . A method according to  claim 6  wherein the source material is added in a plurality of charges wherein each charge comprises no more than one half of the weight of the molten pool at the commencement of the addition of the charge and preferably not more than one quarter of the weight of the molten pool at the commencement of the addition of the charge. 
     
     
         9 . A method according to  claim 1  wherein the method further comprises as an initial step, forming a molten pool of a fluxing agent and (i) adding collector to the molten fluxing agent, (ii) adding at least part of the source material into the pool of molten collector metal and wherein (i) and (ii) can be added simultaneously or separately. 
     
     
         10 . A method according to  claim 9  wherein (i) and (ii) are added separately and the collector metal is added prior to the source material. 
     
     
         11 . A method according to  claim 10  wherein the collector metal is added in sequential charges, and the weight of each charge is greater than 5 g and less than 50% of the weight of the molten pool at commencement of addition. 
     
     
         12 . A method according to  claim 1  wherein the source material is added to the molten collector metal without the source material being in admixture with fluxing agent. 
     
     
         13 . A method according to  claim 9  wherein the fluxing agent comprises at least 80% by weight of borax. 
     
     
         14 . A method according to  claim 1  wherein the particulate source material mixture further comprises a fluxing agent. 
     
     
         15 - 16 . (canceled) 
     
     
         17 . A method according to  claim 1  wherein smelting of the gold rich source material in a crucible further comprises:
 forming a molten pool of fluxing agent in the crucible; 
 forming a molten pool of collector metal selected from the group consisting of copper, silver, gold and platinum group metals, beneath the molten pool of fluxing agent; and 
 adding the gold rich source material to the molten pool of fluxing agent. 
 
     
     
         18 . A method according to  claim 17  wherein the collector metal comprises copper. 
     
     
         19 . (canceled) 
     
     
         20 . A method according to  claim 17  wherein the molten pool of collector metal is formed by addition of collector metal to a molten pool of fluxing agent and providing a temperature not less than the melting point of the collector metal. 
     
     
         21 . A method according to  claim 1  wherein the molten pool of collector metal is formed by the addition of coarsely divided collector metal preferably of particle size of at least 1 mm. 
     
     
         22 . A method according to  claim 1  wherein the collector metal is present in an amount of from 5 to 5000 parts per 100 parts source material. 
     
     
         23 . A method according to  claim 1  wherein the formation of the molten pool of metal and addition of source material is conducted in a vessel which comprises less than 10% by weight carbon and less than 10% by weight of carbides. 
     
     
         24 - 26 . (canceled) 
     
     
         27 . A method according to  claim 1  further comprising treating the gold-containing source material to at least partially remove base metal prior to forming a molten pool comprising at least one metal selected from the group consisting of copper, silver, gold and platinum group metal. 
     
     
         28 - 54 . (canceled)