Abstract: In a process for continuously separating uranium isotopes, .sup.235 U and .sup.238 U, by oxidation-reduction chromatography using a column of an anion exchanger, the separation of uranium isotopes and the regeneration of the oxidizing agent and reducing agent both deactivated during the separation of uranium isotopes can be simultaneously effected in a single column by returning to and passing through the column of an anion exchanger having a uranium adsorption zone an eluate containing a deactivated oxidizing agent and a deactivated reducing agent to regenerate the deactivated oxidizing agent and the deactivated reducing agent and to form an oxidizing agent zone, and returning to and passing through the column the regenerated reducing agent for the reduction of uranium.

Abstract: A composite porous material comprising a particulate inorganic porous material and, contained in the pores of the material, an organic resin having a micro-void. The composite porous material has a surface area larger than that of the inorganic porous material. The composite porous material has a high dimensional stability comparable to that of an inorganic porous material while exhibiting a high separating and adsorbing capacity comparable to that of the conventional ion exchange resin or chelate resin. Therefore, it can advantageously be used as an adsorbent for various compounds or ions as well as a packing material for gas or liquid chromatography.

Abstract: A method for the separation of the isotopes of carbon comprising contacting an aqueous solution containing an acid-dissociated type chemical species of a carbon-containing acid and a non-dissociated type chemical species of said acid with an anion exchange resin as a solid phase, thereby to allow an isotope exchange reaction with respect to carbon to proceed between said acid-dissociated type chemical species and said non-dissociated type chemical species and, concurrently, to adsorb said acid-dissociated type chemical species on said anion exchange resin, and separate C.sup.12 and C.sup.13 respectively into a solution phase and the solid phase or the solid phase and a solution phase, whereby C.sup.13 is concentrated. This method can be practised at an extremely favorable efficiency and inexpensive cost, as compared with the prior art method for the separation utilizing a distillation method or a chemical exchange method between gas--liquid phases, gas--solution phases, solution--solution phases and the like.