Abstract: Disclosed is a continuous solid/liquid extraction device including at least, from upstream to downstream: a mixer including an inlet and an outlet; an extraction coil including an inlet and an outlet, the inlet of the coil being connected to the outlet of the mixer; and a phase separator connected to the outlet of the coil. The same coil includes an ultrasonic probe with radial irradiation placed in the center of the coil.

Abstract: A method for extracting the tantalum from an acid aqueous phase A1 comprising at least one step comprising the bringing of the aqueous phase A1 into contact with a phase A2 not miscible with water, and then the separation of the aqueous phase A1 from the phase A2, the phase A2 consisting of one ionic liquid or a mixture of ionic liquids as an extractant. A method for recovering the tantalum that implements this extraction method and to a use of an ionic liquid or of a mixture of ionic liquids as an extractant, in order to extract the tantalum from such an aqueous phase A1.

Abstract: A method for extracting the tantalum from an acid aqueous phase A1 comprising at least one step comprising the bringing of the aqueous phase A1 into contact with a phase A2 not miscible with water, and then the separation of the aqueous phase A1 from the phase A2, the phase A2 consisting of one ionic liquid or a mixture of ionic liquids as an extractant. A method for recovering the tantalum that implements this extraction method and to a use of an ionic liquid or of a mixture of ionic liquids as an extractant, in order to extract the tantalum from such an aqueous phase A1.

Abstract: The invention relates to a process fop trapping gaseous ruthenium on polyvinyl pyridine, more particularly usable for recovering radioactive ruthenium from irradiated nuclear fuels.This process consists of contacting a gas containing ruthenium in gaseous form with an adsorbent (11b) constituted by a vinyl pyridine polymer or copolymer for fixing the ruthenium to the latter. The gas can be constituted by yapours from a concentrate of fission products containing ruthenium, which has been heated (at 31) in the presence of an oxidizing agent for volatilizing the ruthenium.

Abstract: The invention relates to a process for the separation of at least one element such as Nb, Sb, Ce+Pr, actinides and elements from groups VIIb and VIII of the Periodic Classification of Elements from aqueous solutions resulting from the reprocessing of spent nuclear fuels.This process consists of contacting said aqueous solution with a solid resin based on a vinyl pyridine polymer or copolymer and separating from said solution the resin used for fixing said element or elements.The resin is in particular a poly(vinyl-4-pyridine) powder in crosslinked from and the separated elements are e.g. ruthenium, rhodium, palladium, technetium, manganese, cobalt, iron, nickel, cerium and praseodymium.

Abstract: The invention relates to the use of thioether ligands in accordance with the formula: ##STR1## in which R.sup.1 and R.sup.2, which can be the same or different, represent alkyl radicals, R.sup.3 is an alkyl radical and A represents a divalent radical chosen from among the radicals of formula:--(CH.sub.2).sub.m ----(CH.sub.2).sub.n --X--(CH.sub.2).sub.p -- ##STR2## in which m is equal to 0 or is an integer from 1 to 6, n and p are integers between 1 and 6 and X represents O or S, for recovering the palladium present in a nitric aqueous solution (A.sub.0) for dissolving irradiated nuclear fuel elements.For example, it is possible to use the ligand of formula (I) with A representing CH.sub.2 --S--CH.sub.2 and R.sup.1 and R.sup.2 representing C.sub.10 H.sub.21.