Abstract: The invention relates to the dissolving of plutonium and/or other radioactive elements in an aqueous solution by microwave heating.According to the invention, solid or liquid products containing plutonium and/or other radioactive elements are introduced into a container (7) containing an acid solution, comprising hydrofluoric acid and nitric solution, followed by the microwave heating of the solution containing these products using a chamber or tank (5) placed in a tight enclosure (1), which is supplied with microwaves by means of a coaxial cable or a waveguide (11) connected to the generator (9) located outside the enclosure.The solid products can be plutonium dioxide PuO.sub.2 or organic or mineral radioactive waste materials such as gloves, cellulose products, ion exchange resins, etc. The liquid products can be contaminated organic solvents such as tributyl phosphate in dodecane.

Abstract: A process for separating iron +3 from uranium +6 is an organic solution of a neutral phosphine oxide and an acid organophosphorus compound. The uranium-containing organic solution is contacted with aqueous oxalic acid or an aqueous mixture of phosphoric acid and sulfuric acid so that most of the uranium remains in the organic solution and most of the iron passes into the aqueous acid.

Abstract: The invention relates to an air-tight, shielded enclosure equipped for emission spectrometry. The air-tight enclosure (4) outside of which the high-frequency generator (1) and the spectrometer (3) are located, contains the inductor plasma source (2). The enclosure is provided with an insulating and biologically protective high-frequency lead-through (6), a Faraday cage (16), an air removing hood (17), and a baffle output (24) of the image of the plasma. This equipment makes it possible to apply emission spectrometry to the analysis of radioactive elements.

Abstract: The invention relates to a process for recovering and purifying the molybdenum from a solution containing more molybdenum than vanadium.The process of the invention comprises the step of contacting the solution which contains molybdenum and vanadium, originally at a pH at least equal to 11 with an excess of an ammonium salt sufficient to precipitate the greatest part of vanadium in the form of solid ammonium vanadate, this excess being yet hot higher than a value such that after precipitation of vanadium, the quantity of ammonium having not reacted with the vanadate would be over a concentration which would account for risks of precipitating also molybdenum which is contained in the liquid phase of the supernatant.The molybdenum which is obtained is of industrial grade.

Abstract: The invention relates to a method for the separation in an induction furnace of a metallic phase and scoriae in a crucible 1 essentially transparent to an electromagnetic field. The method consists of subjecting materials in a first zone 14 to an electromagnetic field of frequency enabling the direct coupling of the inductor 10 with the scoriae, then in a second zone to an electromagnetic field of reduced frequency enabling, under the effect of the centripetal forces produced, the assembling of the metallic phase 28 in the axial region of the crucible.

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.

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.

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.

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

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.