Abstract: Alkaline solutions containing sulfate and sodium ions such as uranium leach liquors, are treated with cationic ion exchange resins in the ammonium form to form a solution containing soluble ammonium salts and complexes; the solution is further treated to convert the soluble sulfates into insoluble sulfates and, in the case of uranium, further treating to separate the uranium by heat and/or acidification. The ammonium can be recovered and reused as ammonium carbonate to regenerate the ion exchange resin whereby sodium ions are eluted from the resin in the form of sodium carbonate which is converted to sodium hydroxide and re-cycled for use as leaching solution.
Type:
Grant
Filed:
February 8, 1978
Date of Patent:
March 23, 1982
Assignee:
Compagnie Generale des Matieres Nucleaires (COGEMA)
Inventors:
Pierre Mouret, Georges Lyaudet, Angelo Sialino, Rino Berri
Abstract: The probe comprises two inductance windings mounted in opposition and conted to an a.c. generator, a measurement winding placed at right angles between the two inductance windings and a measurement voltage detector. A compensation winding is placed coaxially and symmetrically with the measurement winding in relation to the axis of the inductance windings, thus permitting enhanced sensitivity of the probe and a directional effect. Potential applications include continuous recording of magnetic susceptibility along a vertical borehole wall and ore sorting on a conveyor belt.
Type:
Grant
Filed:
February 22, 1979
Date of Patent:
July 7, 1981
Assignee:
Compagnie Generale des Matieres Nucleaires (COGEMA Groupe C.E.A.)
Abstract: Uranium is recovered from alkaline leach liquors of uranium ores by treating the leach liquors with an ion exchange resin in the ammonium form to provide a solution of salts and complexes of uranium and ammonium from which the uranium is separated by treating with heat or an acid.
Type:
Grant
Filed:
February 8, 1978
Date of Patent:
March 17, 1981
Assignee:
Compagnie Generale des Matieres Nucleaires (Cogema)
Abstract: In a process for the recovery of uranium from a wet-process phosphoric acid, comprising treating in an extraction step the preliminarily oxidized acid first with an organic solvent consisting essentially of a dialkylphosphoric acid and a trialkyphosphine oxide dissolved in an inert and unreactive organic solvent whereby there are obtained a uranium-free phosphoric acid and an organic extract consisting essentially of the solvent containing the major portion of uranium; then, in a reextraction step, separating the uranium from the organic extract as ammonium uranyl tricarbonate by reacting the organic extract with ammonium hydroxide and ammonium carbonate; and recycling the uranium-free solvent to the extraction step; an improvement comprises treating the organic extract in a reextraction apparatus having at least two stages, by (a) introducing the extract at the head of the first stage; (b) countercurrently introducing ammonia or ammonium hydroxide solution at the bottom of the first stage; the pH of the firs
Type:
Grant
Filed:
July 5, 1978
Date of Patent:
December 9, 1980
Assignees:
Compagnie Generale des Matieres Nucleaires (COGEMA) S.A., APC - Azote et Produits Chimiques S.A.
Abstract: The invention relates to a process for the treatment of an uraniferous ore containing sulfur in the form of sulfates or sulfides with one or more alkaline solutions containing sodium carbonate in the presence of an oxidant, for extracting uranium in the form of soluble uranium salt in said solution.It comprises subjecting the ore, in a first step, to the action of a dilute pre-leach solution of sodium carbonate, whose concentration does not substantially exceed, or by very little, that which is required for the solubilization of the major part of the sulfur initially contained in the ore to convert it to sulfate in the presence of the oxidant and, in a second step, to the action of a leach solution, more concentrated in sodium carbonate, enabling the extraction and solubilization in the medium of the major part of the uranium still contained in the ore, not extracted in the pre-leach medium of the first step.
Type:
Grant
Filed:
February 8, 1978
Date of Patent:
June 3, 1980
Assignee:
Compagnie Generale des Matieres Nucleaires (COGEMA)
Inventors:
Paul J. Lafforgue, Jean Grenier, Guy Rivoire