Earth Sciences Limited

Roman Z Pyrih

Robert S Rickard

Orin F Carrington

The invention is an improvement in the process for recovering uranyl uranium from solutions in which the uranyl uranium is recovered with an liquid-liquid solvent extraction agent dissolved in an inert solvent, the loaded agent scrubbed with water, the scrubbed agent stripped with ammonium carbonate solution to form a slurry of ammonium uranyl tricarbonate, the stripped agent returned to the liquid-liquid solvent extraction step, and the ammonium uranyl tricarbonate calcined to a uranium oxide product, the improvement which comprises stripping the uranium from the ion exchange agent with an alkali metal carbonate rather than ammonium carbonate, scrubbing the loaded agent with acidified alkali carbonate strip solution prior to stripping, and regenerating the stripped liquid-liquid solvent extraction agent with a mineral acid before return to the liquid-liquid solvent extraction circuit.

Process for recovering uranium from wet process phosphoric acid

An improvement in the process for the recovery of uranium from a phosphoric acid solution derived from the acidification of uraniferous phosphate ores including the steps of reducing the uranium in the phosphoric acid solution to the uranous form and contacting the resulting solution with a liquid-liquid solvent extraction agent which is a mixture of mono- and di-(alkyl-phenyl) esters of orthophosphoric acid dissolved in an inert organic diluent, to effect recovery of the uranium with the liquid-liquid solvent extraction agent, the improvement being maintaining the proper ratio of the mono and di-components of the liquid-liquid solvent extraction mixture which comprises removing dissolved and entrained uranium process organics from the raffinate resulting from said liquid-liquid solvent extraction step and recycling the removed organics to said liquid-liquid solvent extraction step.

Recovering uranium from wet process phosphoric acid with alkylphenyl

Improvement in the process for recovering uranium from wet-process phosphoric acid solution derived from the acidulation of uraniferous phosphate ores by the use of two ion exchange liquid-liquid solvent extraction circuits in which in the first circuit (a) the uranium is reduced to the uranous form; (b) the uranous uranium is recovered by liquid-liquid solvent extraction using a mixture of mono- and di-(alkyl-phenyl) esters of orthophosphoric acid as the ion exchange agent; and (c) the uranium oxidatively stripped from the agent with phosphoric acid containing an oxidizing agent to convert uranous to uranyl ions, and in the second circuit (d) recovering the uranyl uranium from the strip solution by liquid-liquid solvent extraction using di(2-ethylhexyl)phosphoric acid in the presence of trioctylphosphine oxide as a synergist; (e) scrubbing the uranium loaded agent with water; (f) stripping the loaded agent with ammonium carbonate, and (g) calcining the formed ammonium uranyl carbonate to uranium oxide, the improvement comprising: (1) removing the organics from the raffinate of step (b) before recycling the raffinate to the wet-process plant, and returning the recovered organics to the circuit to substantially maintain the required balance between the mono and disubstituted esters; (2) using hydogren peroxide as the oxidizing agent in step (c); (3) using an alkali metal carbonate as the stripping agent in step (f) following by acidification of the strip solution with sulfuric acid; (4) using some of the acidified strip solution as the scrubbing agent in step (e) to remove phosphorus and other impurities; and (5) regenerating the alkali metal loaded agent from step (f) before recycling it to the second circuit.

Uranium recovery from wet process phosphoric acid

A process for recovering vanadium values from carbonaceous type vanadium ores, and vanadium scrap, such as vanadium contaminated spent catalyst, is disclosed which comprises roasting the vanadium containing material in air at a temperature less than about 600.degree. C to produce a material substantially devoid of organic matter, subjecting said roasted material to a further oxidizing roast in an oxygen atmosphere at a temperature of at least about 800.degree. C for a period sufficient to convert substantially all of the vanadium to the soluble form, leaching the calcine with a suitable dilute mineral acid or water at a pH of neutral to about 2 to recover vanadium values, precipitating vanadium values as iron vanadate from the leach solution with a soluble iron compound at a pH from neutral to about 1, and recovering ferrovanadium from the iron vanadate by a reduction vacuum smelting operation. The conversion of vanadium in the ore to the soluble form by the oxidizing roast is accomplished without the addition of an alkaline salt during calcining.

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Golden, CO, United States of America

Roman Z Pyrih