摘要:
The present invention relates to a process for the preparation of silver-containing polymer beads, characterized in that I) a mixture of a) styrene b) crosslinker c) organic silver salt d) free-radical initiator and, if appropriate, e) inerting agent is produced, and II) the resultant mixture is cured in an aqueous phase at an increased temperature to form polymer beads.
摘要:
The present invention relates to the use of inorganic salts for increasing the adsorption of oxoanions and/or thioanalogues thereof to metal-doped ion exchangers, preferably to iron oxide/iron oxyhydroxide-containing ion exchangers, preferably from water or aqueous solutions, and also the conditioning of these metal-doped ion exchangers having increased adsorption behaviour toward oxoanions and/or thioanalogues thereof by using inorganic salts with the exception of amphoteric ion exchangers which have both acidic and basic groups as functional groups.
摘要:
The present invention relates to a process for producing weakly acidic cation exchangers of the polymethacrylic acid type by alkaline saponification of a crosslinked copolymer of alkyl methacrylate and methacrylic acid.
摘要:
The present invention relates to a method for producing iron oxide/iron oxyhydroxide-containing carboxyl-bearing ion exchangers, which is characterized in that a) a bead-type carboxyl-containing ion exchanger is contacted in aqueous suspension with iron(III) salts or a′) an aminomethylated crosslinked polystyrene bead polymer is contacted in aqueous suspension with iron(III) salts and with chloroacetic acid and b) the suspensions obtained from stages a) or a′) are adjusted to pHs in the range from 3 to 14 by adding alkali metal hydroxides or alkaline earth metal hydroxides and the resultant iron oxide/iron oxyhydroxide-containing ion exchangers are isolated by known methods, to the ion exchangers themselves their, and also to their use for the adsorption of heavy metals, in particular arsenic.
摘要:
The invention relates to a process for producing monodisperse ion-exchanger gels with a particle size of from 5 to 500 μm, obtainable via a) production of a non-crosslinked monodisperse seed polymer with a particle size of from 0.5 to 20 μm via free-radical-initiated polymerization of monoethylenically unsaturated compounds in the presence of a non-aqueous solvent, b) addition of an active styrene-containing monomer mixture as feed to this seed polymer, permitting the monomer mixture to penetrate into and swell the seed, and polymerizing the mixture at an elevated temperature, if appropriate with one or more repetitions of the steps of addition of monomer mixture, penetration and swelling, and polymerization, and where during the final addition the monomer mixture comprises from 2 to 50% by weight of crosslinking agent, and c) functionalization by means of a sulfonating agent to give cation exchangers or via amidomethylation with subsequent hydrolysis to give anion exchangers, or chloromethylation with subsequent amination.
摘要:
The present invention relates to a process for the preparation of iron-oxide- and/or iron-oxyhydroxide-containing ion exchangers by polymerizing iron-oxide- and/or iron-oxyhydroxide-containing mixtures and functionalizing the resultant polymers.
摘要:
The present invention relates to a process for preparing selective ion exchangers based on crosslinked vinylaromatic polymers and containing iminoacetic acid units of the general formulas (I) and (II) wherein X represents hydrogen or an alkali metal ion, by reacting a weak-base anion exchanger bearing primary amino groups with monochloro-acetic acid and/or an alkali metal salt of monochloroacetic acid at a temperature of from 70 to 110° C. and a pH of from 7 to 11.
摘要:
The present application relates to novel monodisperse, gel-type or macroporous picolylamine resins which are based on at least one monovinylaromatic compound and at least one polyvinylaromatic compound and/or a (meth)acrylic compound and contain tertiary nitrogen atoms in structures of the general formula (I) as functional group, where R1 is an optionally substituted radical from the group consisting of picolyl, methylquinoline and methylpiperidine, R2 is a radical —(CH2)q—COOR3, R3 is a radical from the group consisting of H, Na and K, m is an integer from 1 to 4, n and p are each, independently of one another, a number in the range from 0.1 to 1.9 and the sum of n and p is 2, q is an integer from 1 to 5 and M is the polymer matrix, a process for preparing them and their uses, in particular the use in hydrometallurgy and electroplating.
摘要:
The present invention relates to a method for improved removal of cations, preferably alkaline earth metals, in particular calcium and barium, from aqueous solutions using chelating resins having aminomethylphosphonic acid groups and iminodimethylphosphonic acid groups having high dynamic absorption capacity for cations at a low residual content of the cations and high regeneration efficiency, and a markedly lengthened loading duration of the chelating resin, to the chelating exchangers themselves, and also to uses thereof.
摘要:
The present application relates to a process for the adsorption of radionuclides from waters or aqueous solutions such as arise in nuclear plants, by contacting the water to be treated or the aqueous solutions with monodisperse, macroporous ion exchangers.