Duval Corporation

Davy Mckee (Stockton) Limited

David Naden

Archibald W Fletcher

Leonard R Ochs

David G Webster

Gordon Willey

Harald Weber

A process is described for recovering metal values from a zinc-containing complex sulphide material comprising leaching the material in a first leaching stage under non-oxidative conditions with a controlled amount of an aqueous chloride lixiviant solution containing cupric chloride in an amount which is selected so as to solubilize at least a part of the zinc in the material and to precipitate a quantity of cupric sulphide substantially equivalent on a molar basis to the zinc leached from the material, the lixiviant solution further containing sufficient of a source of chloride ions other than cupric chloride to ensure solubilization of metal chlorides present, recovering from the first leaching stage a zinc chloride-containing leach liquor, recovering metal values from said leach liquor in a metal recovery section, treating solids from the first leaching stage under oxidizing conditions in a second leaching stage with a liquor containing hydrochloric acid and metal chlorides thereby to solubilize further metal values from the solids, to precipitate iron values and to regenerate cupric chloride-containing lixiviant solution for use in the first leaching stage, and recovering from the second leaching stage (a) a solids residue consisting essentially of (i) iron values in the form of ferric hydroxide and jarosite and (ii) sulphur and that is substantially free from non-ferrous metal values and (b) a cupric chloride-containing lixiviant solution for recycle to the first leaching stage.

Metal sulphide extraction

A control device for controlling the transfer of adsorbent to and from stages of an adsorbant-in-pulp contactor comprises a vessel for receipt of an adsorbent-pulp mixture and having an inclined screen for retention of adsorbent particles and passage of pulp, means for transferring adsorbent-pulp mixture to the vessel, means for measuring the volume of adsorbent or of adsorbent-pulp mixture in the vessel, and outlet means adjacent the lower end of the screen for recovery of drained adsorbent solids.

Control device

Growing community of inventors

Stockton-on-Tees, United Kingdom

David Naden