The residual hydrogenation catalyst from the hydrogenated nitrile rubber solution is recovered by using two steps such as (1) the catalyst extraction step with an ammonium salt and water (optionally including an oxidation step) to extract catalyst from the HNBR polymer chain to the solvent and then (2) the separation/column recovery step with the column packed with functional ion exchange resins for the separation of ammonia-catalyst complex from hydrogenated nitrile rubber solution and the column recovery for the high catalyst recovery with functional groups of resins. The ammonium salt for the catalyst extraction step is selected from ammonium chloride, ammonium bromide, ammonium iodide, and ammonium acetate. The functional groups in the functional ion exchange resins for packing the column is selected from thiourea, thiouronium, thiol, amine, diamine, triamine, TMT, dithiocarbamate, and carbodithioate.

A method for conditioning of spent ion exchange resins from nuclear facilities comprises the steps of: mixing the spent ion exchange resins with water to form a reaction mixture; setting and controlling the pH of the reaction mixture in a range from 1.0 to 3.5, preferably in a range from 2.0 to 3.0; adding an oxidant to the reaction mixture, with the temperature of the reaction mixture maintained at 90?? C. or less so that the spent ion exchange resin and the oxidant react with each other to form an aqueous reaction solution comprising the organic reaction products of the spent ion exchange resin; and electrochemically oxidizing the organic reaction products, wherein carbon dioxide is produced and a carbon-depleted aqueous reaction solution having a TOC (total organic carbon) value of less than 50 ppm is obtained. Furthermore, an apparatus for the conditioning of spent ion exchange resins from nuclear facilities is described.

A method for conditioning of spent ion exchange resins from nuclear facilities comprises the steps of: mixing the spent ion exchange resins with water to form a reaction mixture; setting and controlling the pH of the reaction mixture in a range from 1.0 to 3.5, preferably in a range from 2.0 to 3.0; adding an oxidant to the reaction mixture, with the temperature of the reaction mixture maintained at 90?? C. or less so that the spent ion exchange resin and the oxidant react with each other to form an aqueous reaction solution comprising the organic reaction products of the spent ion exchange resin; and electrochemically oxidizing the organic reaction products, wherein carbon dioxide is produced and a carbon-depleted aqueous reaction solution having a TOC (total organic carbon) value of less than 50 ppm is obtained. Furthermore, an apparatus for the conditioning of spent ion exchange resins from nuclear facilities is described.

In alternative embodiments, the invention provides processes and methods for the recovery, removal or extracting of, and subsequent purification of uranium from a wet-process phosphoric acid using a continuous ion exchange processing approach, where the uranium is recovered from a phosphoric acid, or a phos-acid feedstock using either a dual or a single stage extraction methodology. In both cases an intermediate ammonium uranyl-tricarbonate solution is formed. In alternative embodiments, in the dual cycle approach, this solution is contacted in a second continuous ion exchange system with a strong anion exchange resin then subsequently recovered as an acidic uranyl solution that is further treated to produce an intermediate uranyl peroxide compound which is ultimately calcined to produce the final uranium oxide product. In alternative embodiments, in the single cycle case, the intermediate ammonium uranyl-tricarbonate solution is evaporated to decompose the ammonium carbonate and produce an intermediate uranium carbonate/oxide solid material. These solids are digested in an acid medium, and then processed in the same manner as the secondary regeneration solution from the dual cycle process to produce an intermediate uranyl peroxide that is calcined to produce a final uranium oxide product.

In alternative embodiments, the invention provides processes and methods for the recovery, removal or extracting of, and subsequent purification of uranium from a wet-process phosphoric acid using a continuous ion exchange processing approach, where the uranium is recovered from a phosphoric acid, or a phos-acid feedstock using either a dual or a single stage extraction methodology. In both cases an intermediate ammonium uranyl-tricarbonate solution is formed. In alternative embodiments, in the dual cycle approach, this solution is contacted in a second continuous ion exchange system with a strong anion exchange resin then subsequently recovered as an acidic uranyl solution that is further treated to produce an intermediate uranyl peroxide compound which is ultimately calcined to produce the final uranium oxide product. In alternative embodiments, in the single cycle case, the intermediate ammonium uranyl-tricarbonate solution is evaporated to decompose the ammonium carbonate and produce an intermediate uranium carbonate/oxide solid material. These solids are digested in an acid medium, and then processed in the same manner as the secondary regeneration solution from the dual cycle process to produce an intermediate uranyl peroxide that is calcined to produce a final uranium oxide product.

There is provided a method for obtaining a purified aqueous solution of silicic acid containing less metal impurities such as Cu and Ni using water glass as a raw material with less number of purification steps than that in conventional methods without using any unnecessary additives. The method for producing a purified aqueous solution of silicic acid, the method comprising the steps of: (a) passing an aqueous solution of alkaline silicate having a silica concentration of 0.5% by mass or more and 10% by mass or less through a column filled with a polyamine-, iminodiacetic acid-, or aminophosphoric acid-type chelating resin, and (b) passing the aqueous solution passed in the step (a) through a column filled with a hydrogen-type cation exchange resin.

There is provided a method for obtaining a purified aqueous solution of silicic acid containing less metal impurities such as Cu and Ni using water glass as a raw material with less number of purification steps than that in conventional methods without using any unnecessary additives. The method for producing a purified aqueous solution of silicic acid, the method comprising the steps of: (a) passing an aqueous solution of alkaline silicate having a silica concentration of 0.5% by mass or more and 10% by mass or less through a column filled with a polyamine-, iminodiacetic acid-, or aminophosphoric acid-type chelating resin, and (b) passing the aqueous solution passed in the step (a) through a column filled with a hydrogen-type cation exchange resin.

Disclosed herein are compositions of tricarbazole triazolophane (tricarb) of Formulas (I), (II) and (III): ##STR00001##
wherein R of Formula (I) is selected from a group consisting of alkyl (for example, C.sub.6-C.sub.18), alkyl-substituted phenyl derivatives, and substituted glycol derivatives, among others, or a combination thereof, and R, R and R of Formulas (II) and (III) are independently selected from a group consisting of alkyl (for example, C.sub.6 to C.sub.18), alkyl-substituted phenyl derivatives, and substituted glycol derivatives, or a combination thereof. The disclosure presents examples of thin films composed of the same as well as methods of binding anions from the same.

Disclosed herein are compositions of tricarbazole triazolophane (tricarb) of Formulas (I), (II) and (III): ##STR00001##
wherein R of Formula (I) is selected from a group consisting of alkyl (for example, C.sub.6-C.sub.18), alkyl-substituted phenyl derivatives, and substituted glycol derivatives, among others, or a combination thereof, and R, R and R of Formulas (II) and (III) are independently selected from a group consisting of alkyl (for example, C.sub.6 to C.sub.18), alkyl-substituted phenyl derivatives, and substituted glycol derivatives, or a combination thereof. The disclosure presents examples of thin films composed of the same as well as methods of binding anions from the same.

The agent for selective metal recovery of the present invention includes a material derived from an alga belonging to the order Cyanidiales, which is dead cells or a cell surface layer of an alga belonging to the order Cyanidiales, or an artificial material produced by simulating the cell surface layer, or includes a porphyrin. The metal recovery method of the present invention includes an addition step of adding a material derived from an alga belonging to the order Cyanidiales, which is dead cells or a cell surface layer of an alga belonging to the order Cyanidiales, or an artificial material produced by simulating the cell surface layer, or adding a porphyrin, to a metal solution; and a recovery step of recovering a metal from the metal solution by the material derived from an alga belonging to the order Cyanidiales or the porphyrin.