Method for treating slag

Abstract

The invention relates to a method for treating slag created in the production of blister copper processed directly from concentrate in a suspension smelting furnace, such as a flash smelting furnace, in order to recover the copper, so that at least part of the slag is leached in at least one step.

1 . A method for recovering copper from slag created in the production of blister copper processed directly from concentrate in a suspension smelting furnace, comprising leaching at least part of the slag in at least one step, dissolving copper of the slag, precipitating the dissolved copper and returning the precipitated copper to the smelting process.  
   
   
       2 . The method according to  claim 1 , further comprising granulating and grinding the slag before leaching.  
   
   
       3 . The method according to  claim 1 , wherein the leaching is carried out with sulfuric acid.  
   
   
       4 . The method according to  claim 1 , wherein the leaching is carried out with an ammoniacal solution.  
   
   
       5 . The method according to  claim 1 , wherein the leaching is carried out with a chloridic solution.  
   
   
       6 . The method according to  claim 1 , wherein the leaching is carried out as a bacteria solution.  
   
   
       7 . The method according to  claim 1 , wherein the precipitating of the copper is recovered by hydroxide precipitation.  
   
   
       8 . The method according to  claim 1 , wherein the precipitating of the copper is recovered by sulfide precipitation.  
   
   
       9 . The method according to  claim 1 , wherein the precipitating of the copper is recovered in liquid-liquid extraction and electrolysis as cathode copper.  
   
   
       10 . The method according to  claim 1 , wherein the returning of precipitated copper is conducted back into the suspension smelting furnace.  
   
   
       11 . The method according to  claim 1 , wherein said suspension smelting furnace is a flash smelting furnace.