Upgrading of precious metals concentrates and residues

摘要

A process for upgrading a precious metals-containing concentrate or residue results in near-quantitave removal of base metals and several impurity elements at elevated temperatures. The precious metals- containing concentrate or residue is exposed to oxygen or an oxygen- containing evironment in an oxidative pre-treatment step followed by treatment with a hydrochlorinating agent in a hydrochlorination step to form an upgraded concentrate or residue.