Sherritt International Corporation

Sheritt International Corporation

Preston Carl Holloway

Michael J Collins

Jan Tjeerd Smit

Aysan Molaei

Kelvin Richard Buban

Nigel Edwin Tuffrey

Alain Tshilombo

Eugene William Yuzda

Jan Smit

Michael Joseph Collins

A process to recover nickel, cobalt and copper by co-processing copper-containing sulphide concentrate feed containing one or more of arsenic, antimony, and bismuth, and laterite ore feed containing nickel and cobalt by pressure oxidative leaching. The sulphide concentrate and oxygen are controlled to produce sulphuric acid to leach nickel, cobalt, copper and acid soluble impurities into a liquid phase of an acidic leach slurry, to precipitate iron compounds and a majority of the arsenic, antimony and bismuth as solids, and to produce heat to heat the incoming feeds to a temperature above 230° C. Reacted slurry is withdrawn, solids are separated, and the PLS solution contains the nickel, cobalt, copper and acid soluble impurities. A first solution purification stage on the PLS neutralizes free acid, precipitates one or more of iron, aluminum, chromium and silicon, and, separates as solids, the precipitated impurities and other solids from a first purified solution. Copper is separated from the first purified solution with a solvent extraction step to produce a raffinate solution reduced in copper and a copper loaded organic phase. The organic phase is stripped and copper is recovered with electrowinning. A second solution purification stage is conducted on the raffinate by one or both of neutralizing free acid and precipitating one or more of iron, aluminum, chromium and silicon, followed by separating as solids, the precipitated impurities and other solids from a second purified solution. Nickel and cobalt are recovered as mixed hydroxides or mixed sulphides from the second purified solution.

Co-processing of copper sulphide concentrate with nickel laterite ore

An integrated pressure leaching, heap leaching process for recovering copper from sulphidic feed containing iron, arsenic, and copper. Aqueous feed slurry of the sulphidic feed is pressure oxidized to form a liquid phase containing free sulphuric acid and aqueous copper sulphate, and to precipitate arsenic as solid iron arsenic compounds. Treated slurry is withdrawn from the pressure vessel and the liquid phase is separated from the solids. Copper is recovered from the separated liquid phase and generates a solution enriched in acid and depleted in copper. At least a portion of this solution is neutralized in a copper heap leach to produce a PLS containing copper and reduced in acid. At least a portion of the heap leach PLS is neutralized to produce a solution further reduced in acid, and solids containing copper precipitates, followed by a liquid solid separation.

Integrated pressure oxidative leach of copper sulphidic feed with copper heap leach

Process for recovering one or both of copper and silver from a sulphidic feed containing iron, arsenic, copper and silver by pressure oxidizing an aqueous feed slurry of the sulphidic feed in a pressure vessel to form a liquid phase containing free sulphuric acid and aqueous copper sulphate, and to precipitate arsenic as solid iron arsenic compounds. The process includes operating the pressure vessel at a sufficiently low solids content to maintain a free acid level below 30 g/L in the liquid phase, and providing sufficient heat to maintain a temperature in the pressure vessel above 200&#xb0; C. Copper metal is recovered from the liquid phase and/or silver may be recovered from the solids by cyanide leaching without the need for a jarosite destruction step.

Low acidity, low solids pressure oxidative leaching of sulphidic feeds

Process to recover copper from a process feed including one or more feed components containing a base metal sulphidic feed, iron, copper and arsenic. Process feed and aqueous quench solution are introduced to a pressure oxidative leaching step with a partial pressure of oxygen above 200 kPa to form free sulphuric acid, to solubilize copper and other metal in the feed as aqueous sulphate compounds and to precipitate arsenic as solid iron arsenic compounds. A treated slurry comprising a liquid phase containing sulphuric acid and copper sulphate, and solids containing the iron arsenic compounds is withdrawn and the liquid phase is separated from the solids. To lessen arsenic re-dissolution and to maintain stability of the solid iron arsenic compounds, one or more of temperature, free acid level and residence time of the treated slurry is controlled. Copper metal is recovered from the separated liquid phase.

Recovery of copper from arsenic-containing process feed

There is provided a method of treating a metalliferrous material, comprising providing a metalliferrous material including at least one target metallic element, solubilising the metalliferrous material so as to effect production of an intermediate product including an operative solution. The operative solution includes a solvent component and a solute component. The solute component includes at least one solute component-based target metallic element and each one of the at least one solute component-based target metallic element corresponds to a one of the at least one target metallic element of the metalliferrous material such that the operative solution includes at least one target metallic element. The operative solution is contacted with an operative reagent in an operative reaction zone so as to effect production of a product mixture including an operative reaction product and hydronium ion, wherein the operative reaction product includes at least one operative reaction product-based target metallic element and each one of the at least one operative reaction product-based target metallic element corresponds to a one of the at least one solute component-based target metallic element of the operative solution. At least one hydronium ion depletion agent is provided in the operative reaction zone such that contacting between any one of the at least one hydronium ion depletion agent and the hydronium ion in the operative reaction zone effects a reactive process which consumes the hydronium ion. Each one of the at least one hydronium ion depletion agent include s at least one dissolved aluminium complex material.

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Edmonton, Canada

Preston Carl Holloway