Abstract: New macroporous alkylaminophosphonic chelating resins which exhibit excellent mechanical stability and strength and good chemical stability are characterized by having an apparent density of 0.35 to 0.425 g/ml, a granulometry smaller than 0.8 mm, a water retention of 50 to 60 percent in the acid form, a porosity of 800 to 1100 mm.sup.3 g, a total theoretical capacity for the fixation of calcium ions of not greater than 31 g/l of resin in the sodium form and an osmotic resistance such that more than 90 percent of the beads are intact after 30 shocks. The high resistance to osmotic shock combined with an adequate exchange capacity exhibited by the new resins makes them particularly suitable for use in highly concentrated solutions, such as concentrated electrolytic brines.

Abstract: An apparatus for the continuous production of spherical polymer beads in a restricted size range. Monomer droplets are produced in said size range by subjecting a fine monomer dispersion containing a controlled amount of a surface protective agent to controlled coalescence during passage through a tube (11) under laminar flow conditions. The monomer droplets are delivered from the tube (11) to the top of a polymerizing column (12) of variable cross-section wherein they undergo suspension polymerization in a laminar liquid stream descending through the column. Further polymerization in a separate reactor (30a, 30b) provides the desired polymer beads.

Abstract: A process and apparatus for the continuous production of spherical polymer beads in a restricted size range. Monomer droplets are produced in said size range by subjecting a fine monomer dispersion containing a controlled amount of a surface protective agent to controlled coalescence during passage through a tube (11) under laminar flow conditions. The monomer droplets are delivered from the tube (11) to the top of a polymerizing column (12) of variable cross-section wherein they undergo suspension polymerization in a laminar liquid stream descending through the column. Further polymerization in a separate reactor (30a, 30b) provides the desired polymer beads.

Abstract: The preparation of anion exchange resins having high density and capacity by bromination of particles of crosslinked vinylaromatic copolymers is described. The process is characterized in that particles of crosslinked vinyltoluene copolymers which have been swollen in a solvent are dibrominated using bromine or a bromine-releasing agent, and the brominated particles are then aminated. The product resins can be used for the extraction of metals, particularly uranium, from solutions such as ore leaching liquor.

Abstract: This invention relates to a process for the preparation of high density resins by bromination of particles of crosslinked vinylaromatic copolymers of either the gel type or the ionic or non-ionic macroporous type. The invention is characterized in that crosslinked vinylaromatic polymer particles which have been swollen in a solvent are contacted with bromine or a bromine releasing agent in the presence of an oxidizing agent.

Abstract: Improved process for the chloromethylation of cross-linked vinylaromatic polymers and copolymers wherein a chlorine generator is incorporated into the reactants and a metallic chloride replaces part or all of the sulfuric acid used in forming the chloromethylating complex. The chloromethylated polymer may be further functionalized to produce an ion-exchange resin.

Abstract: Described is an ion exchange resin prepared from a cross-linked vinyl-aromatic polymer carrying recurring active units of the formula --CH.sub.2 NHRPO(OH).sub.2 wherein R is a lower alkylene radical. Such resins are useful in selectively removing metal ions from solutions, and may be prepared, e.g., by reaction of a primary amino-substituted cross-linked copolymer with a phosphorus trihalide and a simple (C.sub.1 -C.sub.3) aldehyde.