| abstract |
A metal is leached from an ore or concentrate with an aqueous solution of an organic chelating agent. In selecting a suitable agent the formula Beta >10 3/Ksp is employed wherein Beta is the stability constant of the chelate composed of the agent and the metal to be leached, and Ksp is the solubility product constant, in water, of the compound in the ore or concentrate which supplies the metal in the chelate. As an example, an aqueous solution of EDTA leaches copper from a carbonate ore in a limestone matrix. Metal values are then recovered from solution by chemical reduction, electrolysis, cementation, sulfide precipitation or pH control. |