Method for separation and leaching of the valuable metals in sulphide materials

US4671945A · kind A · utility

Inventors

• Thomas Thomassen · Sandefjord, NO
• Carl O. Kostol · Kristiansand, NO

Key dates

• Filing date: Oct 29, 1985
• Grant date: Jun 9, 1987
• Expiry date: Oct 29, 2005

Classification

• Technology area (CPC Y): Emerging Cross-Sectional Technologies
• CPC primary: Y02P10/20
• WIPO field: Materials, metallurgy
• WIPO sector: Chemistry

Abstract

This is a method for the complete leaching of the valuable metals in a metal sulphide material which contains copper, zinc, lead, silver and iron by the use of a solution which essentially contains cupric chloride/sulphates. After the valuable metals have been recovered, the solution is regenerated whereby ferrous chloride and cuprous chloride/sulphate is oxidized to a ferric hydroxide solid and a cupric chloride solution respectively. The regenerated solution is split into two part-solutions and returned to the process. One part-solution goes to a metathesis stage where the fresh metal sulphide material is added in large excess with respect to the part-solutions's content of copper. The result is that only the valuable metals like zinc, lead and silver are leached while copper and iron remain in the residue. The other part-solution goes to a leach stage where the residue from the metathesis stage is added. The ratio between the residue and the solution is about stoichiometric, while the characteristic feature of this stage is how the leach operation is performed. This results in a well leached residue and an almost completely reduced solution in just one leach stage. The residue f…