Abstract: A process for making into useful products the uranium and rare earths contained in impure uranium tetrafluoride resulting from the recovery of uranium from phosphoric acid, comprising dissolving it in a hot condition in a nitric medium in the presence of an aluminum compound, treating the resulting solution with a solvent for extracting uranyl nitrate, which contains a phosphoric ester, and separating from the aqueous phase from which the uranium is removed, the solvent which is charged with uranyl nitrate to be made into a useful product, which provides that, in order to achieve easy separation of the aqueous phase from which the uranium has been removed, from the uranyl nitrate extraction solvent:(a) The operation of dissolution of UF.sub.

Abstract: A method of dissolving impure uranium tetrafluoride in a hot state in a nitric acid solution in the presence of an aluminum compound. For the purpose of obtaining a uranyl nitrate solution which can easily be separated from the solid phase formed during treatment, the dissolving is carried out in two stages at an appropriate temperature. The first stage comprises introducing quantities of nitric acid and of the aluminum compound which are insufficient to dissolve the impure uranium tetrafluoride completely, and keeping the resultant suspension agitated for a period of at least 0.5 hour. The second stage comprises introducing quantities of nitric acid and of the aluminum compound which are at least sufficient to dissolve the uranium not dissolved in the first stage, while keeping the suspension agitated.

Abstract: Process for treating oxidized ores with a manganiferous matrix to recover the small quantities of copper, nickel and cobalt, which consists of attacking the aforementioned ore by means of an aqueous solution of H.sub.2 SO.sub.4 with the simultaneous injection of sulfur dioxide, at a temperature which does not exceed boiling point of the medium, at a pH less than 1.5; introducing an alkaline sulfide to precipitate the copper, nickel and cobalt sulfides in the suspension resulting from the attack; and separating by sulfides and the residue by flotation. The process is applicable to attacks on manganiferous nodules obtained from ocean beds as well as to attacks on land manganiferous matrix oxidized ores.

Abstract: A process for extracting the uranium contained in phosphoric acid solutions by means of an extracting agent comprising an alkylpyrophosphoric acid, which comprises bringing into contact, in an agitated condition, the inorganic, phosphoric acid phase and an organic phase containing the extracting agent, thereby producing an emulsion, which is characterized in that, in an extraction unit comprising n stages in a cascade configuration, for each extraction stage, the emulsion is produced in a first step by simultaneously subjecting the two phases for a period of time T.sub.1 to an intense mechanical shearing action corresponding to a shearing coefficient of at least 5000 seconds.sup.-1 in order to multiply the contact surfaces for contact between said two phases, and then said emulsion in a second step is abruptly broke in a time T.sub.2, the sum of the times required for carrying out the two steps being at most 20 minutes.

Abstract: A process for extracting arsenic from aqueous solution to be purified, in accordance with claim 1 of U.S. Pat. No. 2,404,601, which also contains alkali metal carbonate, sulphate, hydroxide or hydrogen carbonate, and which may also contain at least one of the metals vanadium, uranium and molybdenum, comprising caustification of said solutions by means of lime to convert the carbonates into alkali metal hydroxides, followed by separation of an alkali metal hydroxide-enriched liquor and a first precipitate essentially containing calcium carbonate which is subjected to a washing operation, concentration by evaporation of the mixture of the washing liquor of the first precipitate to produce a second precipitate which essentially comprises alkali metal sulphate, which is characterized in that, before the aqueous solution is caustified, the aqueous solution is treated by a magnesium compound in an amount at least equal to the stoichiometric amount required to cause precipitation of magnesium arsenate.

Abstract: A process for extracting arsenic from aqueous solutions containing alkali metal carbonate, sulfate and hydroxide or hydrogen carbonate, at least one metal selected from the group consisting of vanadium, uranium and molybdenum in the form of an alkali metal salt, and inorganic and/or organic impurities, comprising the steps of caustifying the solution with lime to convert the alkali metal carbonates into hydroxides to precipitate the insoluble calcium salts formed, concentrating the solution by evaporation of the effluent liquids originating from the caustification step to obtain a precipitate substantially comprising alkali metal sulfate wherein the caustification is performed in two steps, consisting of (a) treating the solutions with an amount of lime approximately equal to but less than the stoichiometric amount necessary to convert the alkali metal carbonates into hydroxides as a first precipitate, and (b) after separating and washing the first precipitate, treating the resulting liquor with at least the

Abstract: The electrolysis cell according to the invention is concerned with the preparation of Zr or Hf by electrolysis, from a molten mixture of alkali metal or alkaline earth chlorides and fluorides.It comprises a graphite collector which defines the anodic space and which is extended at the lower end below the level of the electrolyte by a metal wall made of metal to be deposited or coated with said metal.The wall may advantageously be made in the form of a porous diaphragm.

Abstract: A process for obtaining molybdenum as a useful product from aqueous solutions to be purified, according to claim 1 of French patent No.

Abstract: The process according to the invention concerns the production of polyvalent metals such as titanium by electrolysis of molten halides.It comprises controlling the permeability of the diaphragm which separates the anolyte from the catholyte, by causing growth or re-dissolution of a deposit of the metal to be produced.The process is applied in particular to the production of titanium by electrolysis from TiCl.sub.4.

Abstract: The process which is the subject of this invention concerns the preparation of titanium by electrolysis from a bath of molten halides.It comprises effecting partial reduction of the TiCl.sub.4 which is used as the starting material in a separate reaction vessel, and then directly feeding the electrolyzing apparatus by means of titanium halides with a valency of less than 3. The partial reduction of the TiCl.sub.4 is effected by means of divided titanium or another metal such as Na.

Abstract: A process for obtaining a dense ion-exchange anionic resin and the product so obtained. The resin is of the type based on a co-polymer of styrene and divinylbenzene. The process involves a liquid phase treatment comprising contacting the resin with bromide in a liquid phase and simultaneously charging the liquid phase with gaseous chlorine while in contact with the resin for reaction to provide a styrene divinylbenzene copolymer ion-exchange anionic resin containing bromine and chlorine groups.

Abstract: The present invention relates to a process for the selective separation of uranium and molybdenum which are contained in an extract resulting from an amino solvent liquid-liquid extraction of a solution resulting from an attack on a molybdo-uraniferous ore by means of sulphuric acid, and which comprises re-extraction of the uranium in the presence of an oxidizing agent by means of an acid solution of an alkali metal chloride, followed by re-extraction of the molybdenum by means of an alkali metal carbonate solution. This process is characterized by using an oxidizing agent such as hydrogen peroxide, a small amount of which is added to the acid alkali metal chloride solution before the latter is brought into contact with the extract. This makes it possible to achieve selective separation of the uranium and molybdenum.

Abstract: A process for separating by means of an organic agent the uranium and the molybdenum contained in an aqueous liquor originating from a sulphuric attack of an urano-molybdeniferous ore which involves placing the said attacking liquor in contact with an organic extraction solution containing at least one tertiary or secondary amine in an (amine)/(Mo) molar ratio of up to 0.8, separating the molybdenum-charged organic phase from the uranium-rich aqueous phase, treating the organic phase with an aqueous liquor containing at least one mineral agent in the form of alkaline and ammonium hydroxide and/or carbonates to form an aqueous solution which is concentrated in molybdate.

Abstract: A cyclic process for the treatment of a uraniferous liquor containing, in addition to the desired metal, sodium carbonate and/or bicarbonate and sodium sulphate, obtained by the alkaline attack of a sulphur-containing uraniferous ore, the said process comprising the neutralization of the uraniferous liquor then the fixation of the uranium and the SO.sub.4.sup.= ions over a strong anion-exchange resin, the elution thereof with an ammonium carbonate and/or bicarbonate solution in the form of an ammonium uranyl carbonate which is subsequently decomposed and ammonium sulphate, the precipitation and the calcination of the precipitated uranates and/or diuranates with regeneration of the eluent solution of ammonium carbonate and/or bicarbonate, the causticiation of the liquor freed from uranium which leaves the anion-exchange resin to eliminate the SO.sub.4.sup.= ions in calcium form, recycling a carbonated and/or bicarbonated liquor which is free from SO.sub.4.sup.

Abstract: An apparatus for the preparation of hot water using solar energy and non-solar auxiliary energy. Solar heated water in a reservoir is provided for utilization if it is at least at a desired temperature. If the solar heated water is not sufficiently hot, an auxiliary gas heater is used to heat a second reservoir of water to at least the desired temperature. A thermostatic mixer is capable of supplying solar heated water mixed with auxiliary heated water, or only auxiliary heated water, or only solar heated water for utilization. The non-solar heater is utilized only when necessary.

Abstract: A control rod having a center of thermal neutron absorbing material is provided specifically for use within the core of a nuclear reactor, extending through the central zone of maximum flux density. The center is formed of a plurality of portions, normally three, arranged end to end and defining joins therebetween. A central one of said portions extends continuously through the zone of maximum flux density with the joins located outward of this zone.

Abstract: Superplastic metal alloys having a high defromation rate are disclosed. Their structure is characterized by the presence of at least two principal constituents, the major one of which is of a particulate globular or elongated shape while the minor one surrounds the first completely or partially in the form of a particle on the boundry surface of the major constituent which is less than 10 .mu.m thick. This invention can be applied to the shaping of alloys in the superplastic state at a high deformation rate above 100% min.sup.-1.

Abstract: A process for preventing freezing of solar collectors by automatic drainage of the water or liquid working fluid contained within the collectors the working fluid is drained from the collector, but remains within the closed solar collector circuit. Apparatus responsive to the pressure exerted on the collector circuit fluid by an external source of pressurized fluid acts to drain and refill the collectors. The pressure is transmitted through a moving transmissio means, which may be a deformable or movable wall, and which prevents transfer of the collector circuit fluid into the external source of pressurized fluid. The apparatus provides two storage tanks, one of which is provided with an auxiliary heater, the thermal yield being substantially improved by arranging one of the two tanks inside the other.

Abstract: A cyclic process for the treatment of a uraniferous liquor containing, in addition to the desired metal, sodium carbonate and/or bicarbonate and sodium sulphate, obtained by the alkaline attack of a sulphur-containing uraniferous ore, the said process comprising fixing the uranium over a first strong anion-exchange resin, eluting it with an ammonium carbonate and/or bicarbonate solution in the form of an ammonium uranyl tricarbonate which is subsequently decomplexed, precipitating and calcinating the precipitated uranates and/or diuranates with regeneration of the eluant solution of ammonium carbonate and/or bicarbonate, passing the liquor which is freed from uranium and leaves the first strong anion-exchange resin into a neutralization zone then over a second anion-exchange resin, eliminating the SO.sub.4.sup..dbd. ions which are subsequently precipitated in calcium form, recycling a carbonate and/or bicarbonated liquor which is free from SO.sub.4.sup..dbd.

Abstract: A process for the concurrent deposition and regeneration of alumina onto a substrate from an aqueous sodium aluminate solution comprising immersing the substrate in an aqueous sodium aluminate solution of which the composition is controlled and adjusted by passage through a regeneration circuit where alumina is added to make up for the quantity deposited. The invention may be used in the production of adsorbents for the lead present in the exhaust gases of internal combustion engines.