US 4,374,096 AGranted

Uranium ore processing

AssigneeCanadian Patents and Development Limited

InventorsJames M. Skeaff, Gordon M. Ritcey, Kazi E. Haque, Bernard H. Lucas

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Abstract

Uranium ores, concentrates, calcines or tailings are processed to remove radium and thorium as well as uranium. Selected ores, concentrates or tailings, or if more appropriate, chlorination calcines thereof, are leached by selected aqueous chlorine-containing media (preferably in two stages) until uranium, radium and thorium are substantially all dissolved, with the insoluble residual solids being suitable for disposal. The leach solution is treated to recover sequentially uranium, usually thorium, and radium by selected techniques. The radium recovered can be disposed of in any environmentally-acceptable manner. The amount of iron in the residual leach liquor should be controlled to avoid iron build-up, with the barren leach solution being suitable for recycle.

Claims17

Dependent claims

A method of recovering separately uranium, thorium, and radium, from solids comprising ores, concentrates, calcines or tailings containing these metals, comprising:

(1) leaching in at least one stage, said U, Th and Ra-bearing solids in finely divided form with aqueous acidic leachant containing at least one of HCl and Cl.sub.2, the leach conditions and stages being selected to cause high proportions of the uranium, thorium and radium to be dissolved;
(2) separating the aqueous leach solution from the solid residue and disposing of the residue;
(3) recovering uranium from the solution by solvent extraciton and precipitation steps;
(4) when economic, recovering thorium from the solution by solvent extraction and precipitation;
(5) recovering radium from the solution by at least one of ion exchange, adsorption, and precipitation, and disposing of the radium;
(6) when iron is present in the leach solution controlling the amount of iron in the solution to avoid any iron build-up therein, and
(7) recycling the resulting depleted chloride solution to step (1).

4 more elements

Dependencies are inferred from the claim text.