Amax Incorporated

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Simon O Fekete

Gordon R Wicker

Gustavo A Meyer

Kenneth Leslie Agnew

Willem P Duyvesteyn

Edward Howard Coulter

Dien F Shieh

Eugene J Michal

Colin Bruce MacKenzie

H Jan Roorda

Philip George Thornhill

A method is provided for extracting at least one of the trivalent ions Fe and Al from an acid solution. The method comprises uniformly mixing the acid solution with a liquid organic extractant comprising an organophosphorus compound and an alkylaromatic sulfonic acid dissolved in a water-immiscible organic solvent, the extractant being selective to the solvent extraction of said trivalent ions under acidic conditions. The molar ratio of the sulfonic acid to the organophosphorus compound is controlled over a range of about 1:4 to 10:1 and the mixing carried out for a time sufficient to effect solvent extraction of said trivalent ions and provide a raffinate substantially impoverished in said trivalent ions and a loaded extractant containing said trivalent ions, following which the loaded extractant is separated from the raffinate.

Selective extraction of iron and aluminum from acidic solutions

Nickeliferous sulfidic materials containing at least one other metal selected from the group consisting of cobalt, copper and iron are leached with an at least 3 N hydrochloric acid solution to produce a pregnant nickel chloride solution. The pregnant nickel chloride solution is treated with a liquid organic extractant to extract the other metals. The nickel chloride raffinate is concentrated with respect to nickel chloride, and the concentrated nickel chloride solution is heated to at least about 750.degree. C. to hydrolyze the nickel chloride to a refined nickel oxide product and a hydrogen chloride-containing gaseous effluent which is recycled to the concentration step and then through water to regenerate the leaching solution.

Hydrometallurgical refining of nickeliferous sulfides

Nickel and cobalt are separated from aqueous process solutions having pH values below about 4 and containing other metal ions by contacting the process solutions with liquid organic extractants containing a mixture of .alpha.-hydroxyoximes and sulfonic acids dissolved in water-immiscible organic solvents.

Selective nickel and cobalt extraction from aqueous acidic solutions

Nickel values contained in oxidic ores are recovered by leaching with sulfuric acid. The ore is slurried with water, preheated to a leaching temperature between about 230.degree. C and about 300.degree. C and the preheated slurry is fed to one or more vigorously agitated autoclaves, operating continuously in series. Sulfuric acid is added incrementally to the preheated slurry to minimize the amount of iron and aluminum in solution until between about 0.15 part and about 0.8 part of acid per part of dry ore is added to the slurry, thereby minimizing the deposition of scale in the autoclaves.

Acid leaching of nickeliferous oxide ores with minimized scaling

An improved method for agglomerative fluid bed roasting of metal sulphide particles. The sulphide particles are fed as an aqueous slurry through the freeboard of the roaster onto the surface of a bed of roasted calcine agglomerate particles fluidized by a free oxygen-bearing gas. Slurry water is evaporated in the bed and the sulphides are roasted therein. The feed rates of sulphide, water and free oxygen-containing gas are controlled to ensure temperatures in the roaster such that fusion occurs during roasting and agglomerated calcine particles are formed with regular, rounded surfaces. Calcine particles small enough to become entrained in the roaster off-gases are readily disengaged therefrom in cyclones to provide substantially dust-free SO.sub.2 -bearing gas. A preferred practice of the method is feeding substantially the stoichiometric amount of free oxygen to convert the sulphide to SO.sub.2 and metal oxide, thereby producing on the one hand a roasted oxide calcine substantially devoid of sulphur and on the other hand an SO.sub.2 -bearing gas substantially devoid of free oxygen. The method is particularly advantageous in the roasting of pyrrhotite concentrates and other sulphide concentrates containing pyrrhotite such as those derived from the nickel-copper ores of the Sudbury Basin.

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Arvada, CO, United States of America

Simon O Fekete