Abstract: A packing for chromatography, comprising a granular adsorbent and a fibrous material which are substantially homogeneously mixed with each other.

Abstract: When a packed column having a pressure-absorbing mechanism satisfies the following conditions, the pressure absorbing mechanism has a sufficient packings-supporting ability in spite of its simplicity, the disorder of flow of fluid is slight and the effect of separation of materials is high: (1) the inside diameter (D cm) is 10 cm or more, (2) the aforesaid pressure-absorbing mechanism comprises solid parts and passage spaces through which packings can pass, (3) the specified circumference ratios of most of said passage spaces are 10/D or more and their lengths in the flow direction are larger than the -1.5th power of the circumference ratio, (4) the above passage spaces exist within 1 cm from any position on the upper and lower sides of the aforesaid solid parts, and (5) the specified shielding degree of the pressure-absorbing mechanism is 0.01 or more and 0.8 or less.

Abstract: A process for the separation of one rare earth metal from another in a mixture of rare earth metals by chromatographic displacement using a complexing agent and a cation exchanger, which process comprises using a cation exchanger having a micro-void volume void ratio of 0.5 to 0.95, preferably 0.5 to 0.88.

Abstract: A process for the enrichment of one isotope in a mixture of uranium isotopes by passing a solution of the mixture in a solvent through an anion exchanger thereby forming on the anion exchanger a boundary (A) between a uranium adsorption zone and an adjacent reducing agent zone and/or a boundary (B) between a uranium adsorption zone and an adjacent oxidizing agent zone, the uranium adsorption zone advancing through the anion exchanger, effecting reduction at the boundary (A) and/or effecting oxidation at the boundary (B), thereby effecting enrichment adjacent said boundary, and separating a fraction enriched in one of said isotopes, which process comprises using as the solvent medium a composition comprising (a) a solvent having a dielectric constant of at least 80 at 20.degree. C., (b) hydrochloric acid and (c) at least one of hydrobromic acid and sulfuric acid, the solvent medium having a hydrogen ion concentration of about 0.1 M/l to about 10 M/l, a total chlorine ion concentration of about 0.