Teck Cominco Metals Ltd.

Cominco, Ltd.

Dilipkumar D. Makwana

Hector M. Lizama

Daniel W. Ashman

Andrew W. Stradling

Juris R. Harlamovs

Jose Alberto Gonzalez Dominguez

Dilipkumar D Makwana

Hector M Lizama

Juris R Harlamovs

Daniel W Ashman

Andrew W Stradling

A method of extracting zinc from a sulphidic ore is provided which comprises bioleaching the ore in a heap with acidophilic microorganisms to produce a pregnant leach solution which is recovered from the bottom of the heap. An integrated process which comprises subjecting the pregnant leach solution to neutralization and solvent extraction to produce a concentrated zinc solution is also provided. Zinc may be recovered from the concentrated solution by means of electrowinning, either in the absence or presence of manganese. Alternatively zinc may be recovered in the form of a zinc compound.

Heap bioleaching process for the extraction of zinc

In one embodiment, a method of electrowinning a metal from an electrolyte comprises the steps of measuring the redox potential of the electrolyte to obtain a measured value, comparing the measured value with a predetermined optimum value and adding a redox agent to the electrolyte to adjust the redox potential of the electrolyte to the optimum value. One embodiment of apparatus (10) for carrying out the method comprises a redox potential measuring device (20) having a housing for the flow of electrolyte therethrough and including a pair of electrodes (22, 24) for measuring the redox potential of an electrolyte flowing through the housing to produce an output measurement value and a redox controller (26) responsive to the output measurement value for controlling the addition of redox agent to the electrolyte of an electrolysis cell (12).

Redox control in the electrodeposition of metals

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Montrose, Canada

Dilipkumar D Makwana