A process for recovery of one or more target metals, selected from precious metals and chalcophile metals as respectively herein defined, from materials containing precious and/or chalcophile metal/s, said process including: (i) leaching the metal containing material with an aqueous solution containing: a "metal liberator" comprising an amino acid; and a "metal retainer" comprising one or more of ammonia, ammonium salts, carboxylic acids, carboxylic acid salts, dicarboxylic acids, dicarboxylic acid salts, hydroxy-carboxylic acids, hydroxy-carboxylic acid salts, ethylene diamine tetra-acetic acid (EDTA) and EDTA salts, to produce a leachate containing the target metal/s; and (ii) extracting the metal from the leachate.

A process for recovery of one or more target metals, selected from precious metals and chalcophile metals as respectively herein defined, from materials containing precious and/or chalcophile metal/s, said process including: (i) leaching the metal containing material with an aqueous solution containing: a "metal liberator" comprising an amino acid; and a "metal retainer" comprising one or more of ammonia, ammonium salts, carboxylic acids, carboxylic acid salts, dicarboxylic acids, dicarboxylic acid salts, hydroxy-carboxylic acids, hydroxy-carboxylic acid salts, ethylene diamine tetra-acetic acid (EDTA) and EDTA salts, to produce a leachate containing the target metal/s; and (ii) extracting the metal from the leachate.