| 摘要 |
<p>1. A method for the bacterially assisted heap leaching of chalcopyrite, the method characterized by the steps of: providing a chalcopyrite containing ore heap to oxidise sulphide minerals therein, the heap containing and/or being inoculated with a sulphide oxidising bacterial culture that either does not oxidise ferrous to ferric or is inefficient at doing so; providing at least a first leach solution pond (or other suitable container), from which feed solution is fed to the heap, and which receives leach solution from the heap; and bleeding a portion of the leach solution and passing same to a means for metals recovery. 2. A method according to claim 1, characterized in that the first leach solution pond is maintained with a low ferric concentration relative to that of ferrous. 3. A method according to claim 1 or 2, characterized in that the first leach solution pond is maintained with an oxidation reduction potential of below 500 mV relative toAg/AgCl2 standard reference. 4. A method according to any one of claims 1 to 3, characterized in that the first leach solution pond is maintained such that the prevailing chemical conditions are conducive to leaching the chalcopyrite whilst being non conducive to surface passivation. 5. A method according to any one of the preceding claims, characterized in that the ore heap is aerated at or near a base thereof. 6. A method according to any one of the preceding claims, characterized in that the oxidation of the chalcopyrite is achieved through the action of chemolithotrophic bacteria. 7. A method according to any one of the preceding claims, characterized in that the method additionally comprises providing a biological contactor inoculated with ferrous oxidising bacteria and a second leach solution pond from which leach solution is fed to the biological contactor and which receives leach solution from the biological contactor. 8. A method according to claim 7, characterized in that leach solution from the first leach pond is able to be fed to the biological contactor. 9. A method according to claim 7 or 8, characterized in that leach solution is able to be fed from the second leach pond to the first leach pond, whereby the level of ferric and/or the pH value in the first leach pond may be controlled to a large extent. 10. A method according to any one of claims 7 to 9, characterized in that leach solution is bled from the biological contactor for passing to a means for metals recovery, the levels of ferric therein facilitating metal recovery. 11. A method according to any one of the preceding claims, characterized in that the biological contactor is provided in the form of a second heap. 12. A method according to claim 11, characterized in that the second heap is formed of relatively inert waste rock inoculated with ferrous oxidising bacteria.</p> |
