Noranda Mines Limited

Noranda Inc.

Robert W Stanley

Serge Monette

Derek G Kerfoot

Kohur Nagaraja Subramanian

G Bryn Harris

Bryn G Harris

Jean-Pierre Barry

Bryn Harris

A process for recovery of platinum and palladium from an impure substantially gold-free precious and base metal-bearing acidic chloride or mixed chloride/sulphate solution comprises the steps of: contacting the acidic solution having a pH less than about 1.5 with an organic solution comprising an 8-hydroxy quinoline solvent extraction reagent, a phase modifier and an aromatic diluent to extract simultaneously platinum and palladium into the organic solution; scrubbing the loaded organic solution to remove co-extracted impurities and acid; stripping the loaded organic with a buffer solution operating in the pH range 2-5 at 20.degree.-50.degree. C. to selectively recover the platinum; stripping the platinum-free loaded organic with 3-8 M hydrochloric acid to recover the palladium; and regenerating the organic solution by washing with water.

Recovery of pure platinum and palladium

A process for the recovery of gold from a precious metal bearing sludge concentrate is disclosed. The process comprises the steps of leaching the sludge with hydrochloric acid and hydrogen peroxide to solubilize at least gold, palladium and platinum, removing silver from the leach slurry as insoluble silver chloride and selectively precipitating gold from the leach solution remaining after removal of silver by reduction with SO.sub.2 in the presence of sodium ions.

Process for the recovery of gold from a precious metal bearing sludge

A hydrometallurgical process for the recovery of cobalt from cobaltite-pyrite concentrates containing substantial amounts of cobalt, arsenic, iron and sulphur is disclosed. The hydrometallurgical process comprises pressure leaching of the cobaltite-pyrite concentrates with a sodium chloride or sodium sulphate solution at a temperature in the range of 130.degree.-160.degree. C. and under oxygen partial pressures in the range of 75-200 psi to solubilize at least 90% of the cobalt content, while simultaneously precipitating most of the iron and arsenic as jarosite and ferric arsenate.

Process for the selective dissolution of cobalt from cobaltite-pyrite

A method is provided for recovering copper values from a copper-bearing hematite residue in a single stage. It comprises leaching the residue in an aqueous sulphuric acid solution in the presence of ammonium, sodium or potassium ions, at a temperature between about 80.degree. C. and the boiling point of the solution so that copper values are dissolved while iron is precipitated as jarosite. The method is particularly suitable for the treatment of residues resulting from an oxidizing pressure leach of copper concentrates.

Hydrometallurgical treatment of copper-bearing hematite residue

This invention provides a novel and an improved hydrometallurgical method for recovering copper values from copper concentrates. The method essentially comprises the following steps: A. forming an aqueous leach solution containing chloride or bromide ions in a predetermined concentration; B. dispersing copper concentrates in such leach solution to form a slurry; C. carrying out the leaching operation of the slurry at an elevated temperature and under an overpressure of oxygen so as to transform a major proportion of the copper values present in the concentrates into a solid basic copper sulphate; D. separating the resulting leach residue containing the basic copper sulphate from the leach solution; and E. recovering the copper values from the obtained leach residue. The process is simple and efficient and can be carried out either batchwise or continuously.

Recovering copper from concentrates with insoluble sulfate forming leach

An improved hydrometallurgical method is provided for producing technical grade molybdic oxide from molybdenite concentrates. According to this method, the molybdenite concentrates are leached in an acid medium having a nitric acid concentration between about 25 gpl and about 50 gpl and an initial sulphuric acid concentration of nil to about 750 gpl, under oxygen pressure of about 100 - 250 psig and at a temperature above 115.degree. C so as to produce technical grade molybdic oxide having not more than 0.1% sulphur. Then a liquid-solid separation of the reaction mixture is effected and the obtained leach liquor is recycled back to the leaching stage optionally after partial neutralization with a basic reagent. The solid is washed and recovered as technical grade molybdic oxide.

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Kirkland, Canada

Robert W Stanley