Treatment of roasted metal sulphide ores and ferrites by leaching with peroxysulphuric acid

Abstract

A process for the separation of metals from a ferrite or a roasted metal sulphide ore is carried out by leaching the ferrite or roasted ore with peroxysulphuric acid (Caro's acid) and separating therefrom a solution containing metals. The roasted ore may contain ferrite and/or ferrite may be added to the ore, either before or after roasting. The leaching with peroxysulphuric acid may be carried out in the presence of gaseous chlorine. The metal sulphide ores may contain substantial proportions of copper and zinc sulphides.

1 . A process for the treatment of a ferrite for the separation of metals therefrom, comprising: 
 (a) leaching said ferrite with peroxysulphuric acid; and    (b) separating a solution containing metals therefrom.    
     
     
         2 . The process of  claim 1  in which the ferrite is a metal ferrite.  
     
     
         3 . The process of  claim 1  in which the ferrite is a multiple oxide of ferric oxide.  
     
     
         4 . The process of  claim 1  in which, in the leaching step, the ferrite is leached with peroxysulphuric acid in the presence of gaseous chlorine.  
     
     
         5 . The process of  claim 1  in which the solution obtained is treated for the recovery of metal values.  
     
     
         6 . The process of  claim 5  in which a solution containing copper and zinc is obtained.  
     
     
         7 . The process of  claim 1  in which Fe +6  obtained by treatment of ferrite with peroxysulphuric acid is used as an oxidant.  
     
     
         8 . The process of  claim 1  in which the ferrite is synthetic ferrite.  
     
     
         9 . The process of  claim 1  in which the ferrite is in an ore, said ore containing ferrite being subjected to leaching with peroxysulphuric acid in step (a).  
     
     
         10 . The process of  claim 9  in which the ore is roasted metal sulphide ore.  
     
     
         11 . The process of  claim 10  in which the roasted ore is ore that has been subjected to a dead roast.  
     
     
         12 . The process of  claim 10  in which the roasted ore is ore that has been subjected to a sulphation roast.  
     
     
         13 . The process of  claim 9  in which the ferrite is in a roasted metal sulphide ore and in which tails obtained in the process contain gold or silver, the step of subjecting such tails to treatment for recovery of the gold or silver therein.  
     
     
         14 . The process of  claim 9  in which the ferrite is in a roasted metal sulphide ore, said process comprising the additional step of subjecting said metal sulphide ore to a roasting step prior to the leaching step so as to form ferrite in said roasted ore.  
     
     
         15 . A process for the treatment of a roasted metal sulphide ore, for the separation of metals therefrom, comprising: 
 (a) leaching said roasted ore with peroxysulphuric acid; and    (b) separating a solution containing metals therefrom.    
     
     
         16 . The process of  claim 15  in which the roasted ore is ore that has been subjected to a dead roast.  
     
     
         17 . The process of  claim 15  in which the roasted ore is ore that has been subjected to a sulphation roast.  
     
     
         18 . The process of  claim 15  in which a solution containing copper and zinc is obtained.  
     
     
         19 . The process of  claim 15  in which, in the leaching step, the roasted ore is leached with peroxysulphuric acid in the presence of gaseous chlorine.