Abstract: A process is provided for preparing ion-exchange resin particles of relatively uniform size by partial functionalization of non-uniform copolymer beads with ion-exchange groups. The non-uniform copolymer beads are preferably functionalized in a manner such that the ion-exchange groups are substituted at available sites which are most accessible to diffusion by functionalizing agents. Due to the size difference between individual copolymer particles, a greater proportion of available sites is functionalized in a small particle when compared to that of a large particle. Due to the greater proportion of ion-exchange groups present in a small particle, the small particle swells relatively more than a larger particle. The result is effectively a narrowing of the size distribution for the partially functionalized resin particles.

Abstract: A process for preparing copolymer beads suitable for conversion to ion exchange resins, comprising forming a polymeric matrix containing a plurality of free radicals, and continuously adding to said matrix, under conditions suitable for polymerizing a monomer feed which is imbibed by and polymerized within the matrices. Ion exchange resins prepared from beads made by such process exhibit improved osmotic and mechanical properties.

Abstract: An improved process for the recovery of precious metal values is disclosed. By this process precious metals in the form of anionic complexes are contacted with a weak-base anion exchange resin capable of complexing with the anionic complex. Such weak-base anion exchange resins contain weak-base functionalities derived from linear or cyclic polyaminoalkylene amines which have more than 1 amine moiety and at least 3 carbon atoms in a 1,X-alkylene moiety or moieties separating at least 1 amine moiety from a second amine moiety (i.e., X is an integer greater than 2).

Abstract: A process for preparing copolymer beads suitable for conversion to ion exchange resins, comprising forming a polymeric matrix containing a plurality of free radicals, and continuously adding to said matrix, under conditions suitable for polymerizing a monomer feed which is imbibed by and polymerized within the matrices. Ion exchange resins prepared from beads made by such process exhibit improved osmotic and mechanical properties.