Agency of Industrial Science and Technology

Director-general of Agency of Industrial Science and Technology

Director-general of the Agency of Industrial Science and Technology

Co-op Chemical Co., Ltd.

Japan As Directed by Director General of Agency of Industrial Science

Kazuo Torii

Takashi Iwasaki

Hiromichi Hayashi

Yoshio Onodera

Takahiro Sekimoto

Osamu Itabashi

Motoyuki Ikegami

Toshikazu Fujisaki

Yutaro Ishida

A novel synthetic mixed-layer silicate consisting of the layers of serpentine and layers of saponite each having a specified chemical composition is proposed, which has excellent dispersibility in water to form a colloidal dispersion capable of being converted into a gel by standing to be useful as a gelating agent exhibiting thixotropy along with unique porosity characteristics which enable the use thereof as an adsorbent. The mixed-layer silicate is prepared by the process comprising the steps of: (a) preparing an acidic aqueous solution containing silicic acid, magnesium salt and aluminum salt; (b) alkalifying the solution by the addition of an alkaline compound to precipitate a hydrous composite oxide containing silicon, magnesium and aluminum; (c) collecting the precipitates of the hydrous composite oxide; (d) admixing the precipitates of the hydrous composite oxide with an aqueous solution of an alkali metal hydroxide to give an aqueous slurry; and (e) subjecting the aqueous slurry of the hydrous composite oxide to a hydrothermal treatment by heating at a temperature up to 500.degree. C.

Synthetic mixed-layer silicate and method for the preparation thereof

Disclosed is a novel hydrous composite oxide of cerium (IV) and phosphorus characterized by the specified chemical composition and the unique X-ray diffractometric pattern, which is useful as an adsorbent or immobilizing agent of strontium ions in an aqueous solution such as radioactive wastes from atomic power plants. The composite oxide prepared by the precipitation reaction of a Ce (IV) salt in an aqueous solution and phosphoric acid can be imparted with an increased adsorption capacity for strontium ions when the precipitates are heat-treated under hydrothermal conditions at up to 300.degree. C. Immobilization of strontium ions adsorbed on the adsorbent can be more complete when the adsorbent bearing strontium ions is dried and subjected to a heat treatment at a temperature of 200.degree. C. or higher.

Hydrous composite cerium-phosphorus oxide for immobilization of

Proposed is a novel synthetic inorganic porous material having a chemical composition of the general formula

Synthetic inorganic porous material and method for the preparation

There are disclosed an organophilic clay which comprises a hydroxypolyoxyethylenealkyl ammonium ion represented by the following formula: ##STR1## wherein R.sub.1, R.sub.2, R.sub.3 and R.sub.4 may be the same or different, and each represent a (CH.sub.2 CH.sub.2 O).sub.n H group (where n is 2 or more, preferably 2 to 20), a hydrogen atom or an alkyl group having 1 to 30 carbon atoms, provided that one to three of R.sub.1 to R.sub.4 is/are a (CH.sub.2 CH.sub.2 O).sub.n H group(s) and at least three of R.sub.1 to R.sub.4 are (CH.sub.2 CH.sub.2 O).sub.n H group(s) and alkyl group(s), being introduced in interlayers of an expandable layer silicate, a method for preparing the same and a gellant for a high polar organic solvent.

Organophilic clay

Growing community of inventors

Sendai, Japan

Kazuo Torii