Unitika Ltd.

Dowa Mining Co., Ltd.

Masahide Hirai

Hiroyuki Uejima

Masahiro Kazigase

Tsutomu Sakaida

Minoru Saito

Mikio Fujimura

Hitoshi Masuda

Kunio Sekine

Shozo Tomoshige

Kozo Kondo

Kodo Ishibashi

A novel method is disclosed which enables gallium and/or indium to be selectively separated and concentrated from a solution containing them in very low concentrations together with many other metal ions in rather high concentrations. The solution is passed through a bed of a chelating ion exchange resin having an amino carboxylic acid group either immediately or after the pH adjustment. Gallium and/or indium adsorbed on the chelate resin is desorbed by eluting with a mineral acid. The eluate, after the pH adjustment, is passed through another bed of a chelating ion exchange resin having an amino carboxylic acid group, and the resin is treated with a mineral acid to elute the metal ions adsorbed on the resin to thereby recover gallium and/or indium in the form of a concentrated solution.

Method of selective separation and concentration of gallium and/or

An etherified phenolic chelate resin prepared by stabilizing and protecting the chelate groups of a phenolic chelate resin and then converting some or all of the phenolic hydroxyl groups into either groups; a process for the production of the etherified phenolic chelate resin; and a method for separating a heavy metal ion from an aqueous solution having a pH of at least 7 by using this etherified phenolic chelate resin.

Process for removing heavy-metal ions from aqueous solution

An etherified phenolic chelate resin prepared by stabilizing and protecting the chelate groups of a phenolic chelate resin and then converting some or all of the phenolic hydroxyl groups into ether groups; a process for the production of the etherified phenolic chelate resin; and a method for separating a heavy metal ion from an aqueous solution having a pH of at least 7 by using this etherified phenolic chelate resin.

Etherified phenolic chelate resin, process for its production, and

A phenolic chelate resin comprising the three-dimensional product obtained by cross-linking a phenolic compound represented by the general formula (I): ##STR1## (wherein M is an alkali metal atom, an ammonium group, or a hydrogen atom, and R.sub.1 and R.sub.2, which may be the same or different, each is a hydrogen atom or an alkyl group having 1 to 3 carbon atoms) with a phenol and an aldehyde. The phenolic chelate resin selectively adsorbs ferric ion and/or cupric ion in an acidic aqueous solution at a pH of 3 and less.

Phenolic chelate resin and method of adsorption treatment

A high adsorption capacity phenolic chelate resin consisting of a heavy metal-adsorbing phenolic chelate resin, containing iminodiacetic acid groups in the phenol nuclei, and having an adsorbability to a heavy metal in the proportion of at least 1.2 m equivalent per g of dried terminal Na type resin, said phenolic chelate resin being prepared from phenols, aldehydes and iminodiacetic acid.

Phenolic chelate resin

A phenolic chelate resin having a high heavy-metal chelating ability and capable of being reused is produced by polycondensing a phenol containing an iminodiacetic acid group with an aldehyde.

Growing community of inventors

Kyoto, Japan

Masahide Hirai