Reduction of ferric ions in cyclic process of leaching and precipitation of copper

Abstract

Abstract FERRIC SULFATE-SULFURIC ACID LEACHING OF NATURALLY OCCURRING, COPPER-BEARING MATERIALS, SUCH AS COPPER MINERALS IN MINE WASTE DUMPS, AND RECOVERY OF THE DISSOLVED COPPER BY PRECIPITATION ON METALLIC IRON ARE CARRIED OUT ON A CYCLIC BASIS, WITH REDUCTION OF FERRIC IONS PRIOR TO THE COPPER PRECIPITATION STEP. THE PREGNANT LEACH SOLUTION IS TREATED WITH A CONTROLLED QUANTITY OF A WATER SOLUBLE REDUCTANT, SUCH AS SULFUR DIOXIDE OR AMMONIUM-BISULFITE, FOR A SUFFICIENT PERIOD OF TIME IN THE PRESENCE OF ACTIVITATED CARBON AS A CATALYST TO MINIMIZE THE FERRIC ION CONTENT THEREOF WHILE SUBSTANTIALLY COMPLETELY CONSUMING THE ACTIVE IONS OF THE REDUCTANT SO WASTEFUL CONSUMPTION OF THE IRON PRECIPITANT WILL BE PREVENTED WHILE INSURING MOST EFFECTIVE PRECIPITATION OF THE COPPER, AND SO AS ALSO TO PROVIDE NOURISHMENT, WHEN AMMONIUM BISULFITE IS EMPLOYED AS THE REDUCTANT, OF IRON-OXIDIZING BACTERIA NORMALLY PRESENT IN THE LEACH SOLUTION.

Inventors

• 👤 Henry R Spedden
• 👤 John A Apps
• 👤 Donald F Lowe

Bibliographic Details