RECOVERY OF METAL VALUES LEACHING WITH AMMONIACAL AMMONIUM SALT SOLUTION

The present process involves an improvement in the hydrometallurgical recovery of metal values from metal bearing sources such as ores and the like. The desired metal values are recovered by subjecting a metal bearing source to a reductive roast in a reducing atmosphere after having treated said source with at least one additive. Following the reductive roast the reduced metal bearing source is cooled and extracted by a leaching operation. The separation of various metal values in the metal bearing source may be effected by adding a solid adsorbent to the leach solution whereby selective metal ions are adsorbed thereon. The improvement in the present process comprises pretreating the solid adsorbent prior to use thereof with an acid thereby increasing the loading capacity of the metal ions in the adsorbents as well as kinetics of metal adsorption.