Rapid ferrous sulfate biooxidation

Abstract

Disclosed is an improved process for using iron-oxidizing bacteria to reactivate the raffinate ferrous sulfate solution in chemical leach operations. The process uses a biological raffinate converter, or BRC, as a key feature of the process. The invention process provides enhanced efficiency and commercial utility over the best known biological process for converting raffinate ferrous sulfate. The resulting ferric sulfate then can be recycled back into the bioleaching process of, for example, copper from chalcocite.

We claim:  
     
         1 . A method for regenerating a raffinate solution comprising passing said solution through a system comprising a reactor cell having a first opening to receive said raffinate solution and a second opening through which said raffinate solution may exit, and wherein said reactor cell contains coated packing material which is colonized with metal oxidizing bacteria.  
     
     
         2 . The method of    claim 1   , wherein said packing material is coated with graphite.  
     
     
         3 . The method of    claim 1   , wherein said packing material is coated with sulfide concentrates.  
     
     
         4 . The method of    claim 3   , wherein said sulfide concentrates are pyrite.  
     
     
         5 . The method of claims  1 , wherein said coating is attached to said packing material with a bonding agent.  
     
     
         6 . The method of    claim 5   , wherein said bonding agent is polyethylmethacrylate or paraffin.  
     
     
         7 . The method of    claim 1   , wherein said packing material is further colonized by acidophilic fungi.  
     
     
         8 . The method of    claim 1   , wherein said metal oxidizing bacteria are Thiobacillus.  
     
     
         9 . The method of    claim 1   , wherein said system comprises multiple reactor cells connected in series.  
     
     
         10 . The method of    claim 1   , wherein said raffinate solution contains iron.