| abstract |
A method for the generation of ferric ions comprises establishing in a vessel a population of acidophilic, chemoautotrophic bacteria capable of oxidizing ferrous ions into ferric ions, supplying the vessel with a feed solution of ferrous ions, and maintaining the pH of the contents of the vessel below 3.0. The ferric ion solution withdrawn from the vessel may be used for the leaching of metal or sulphur bearing materials, and ferrous ions produced by the leaching process may be recycled to the vessel for generating the ferric ion solution. |