Tokuyama Soda Kabushiki Kaisha

Tokuyama Corporation

Genji Taga

Yoshiaki Watanabe

Shingo Hiranaka

Masaki Noritake

Yoshiki Fukuyama

Yoshiaki Koga

Teruo Oikawa

Yukio Mizutani

Hiroyoshi Kato

Masahiro Nakamura

Hua-Min Zhang

Masami Enokuchi

Takanori Teshima

A method for removing metal pieces contained in gypsum board wastes from the gypsum board wastes by means of a drum magnetic separator, wherein

Method for removing metal pieces from gypsum board wastes

A stripping liquid of the present invention is used for separating the paper from a plaster/paper laminate such as waste plasterboard, and comprises an aqueous solution of an alkali metal salt or an ammonium salt of carboxylic acid. The stripping liquid is fed onto the surface (paper surface) of the plaster/paper laminate so as to infiltrate into the bonding surface between the plaster and the paper, so that the carboxylate is made present on the bonding surface. Upon stripping off the paper in the presence of the carboxylate, it is allowed to entirely separate the paper from the plaster. Upon mixing the stripping liquid and a nonionic surfactant or a water-soluble organic solvent together, further, the stripping liquid can be quickly and reliably infiltrated into the bonding surface between the plaster and the paper.

Stripping liquid for use in separating paper from plaster/paper laminate

A cement setting accelerator comprising calcium hydroxide particles having an average particle diameter of 3 &#x3bc;m or less, and a cement composition comprising 100 parts by weight of a cement and 0.05 to 10 parts by weight of the above setting accelerator. A wet ground product of calcium hydroxide or a fine precipitate formed by a reaction between a calcium salt and an alkali hydroxide can be used as the above calcium hydroxide particles. This setting accelerator shows a high setting accelerating effect and does not exert a bad influence upon the quality, especially durability of a hardened product of the cement composition.

Cement setting accelerator

Amorphous sodium silicate-metal sulfate composite powder having water softening power and having small hygroscopicity, and useful as a detergent builder is provided. This amorphous sodium silicate-metal sulfate composite powder is characterized in that it contains a metal sulfate, for example, sodium sulfate, as solid solution, and when the SiO.sub.2 /Na.sub.2 O molar ratio is expressed by n and the specific surface area thereof is expressed by S (m.sup.2 /g), n and S satisfy the following expressions:

Amorphous sodium silicate-metal sulfate composite powder

Amorphous sodium silicate powder exhibiting excellent water softening power and suitable as a detergent builder is provided. This amorphous sodium silicate powder is characterized in that when the molar ratio of SiO.sub.2 /Na.sub.2 O is expressed by n and the specific surface area thereof is expressed by S(m.sup.2 /g), the following expressions:

Amorphous sodium silicate powder

There is provided a composite oxide represented by the formula

Process for producing a composite alkali metal oxide

Composite oxide of formula R.sub.2 O.Al.sub.2

Disclosed is a process for the preparation of an anorthite sintered body, which comprises preparing a formed body of at least one powder selected from the group consisting of (i) a calcium type zeolite having an SiO.sub.2 /Al.sub.2 O.sub.3 molar ratio lower than 3, (ii) an amorphous calcination product obtained by calcining said calcium type zeolite and (iii) a mixture of said calcium type zeolite or said amorphous calcination product and an alkaline earth metal compound, and sintering the formed body at a temperature lower than 1000.degree. C.

Process for preparation of anorthite sintered body

An alkaline earth metal aluminosilicate sintered body is obtained by molding a starting mixture of a zeolite having an alkaline earth metal form and an SiO.sub.2 /Al.sub.2 O.sub.3 molar ratio not higher than 3.0 and a boron compound such as boron oxide, and firing the molded body at a temperature lower than 1,000.degree. C. An amorphous calcination product formed by calcining the zeolite may also be used in the starting mixture with the boron compound. This process allows the range of firing temperatures suitable for formation of a sintered body to be varied over a range of from about 50.degree. to 150.degree. C. or more while also allowing lower firing temperatures than in the absence of the boron compound to be used while still obtaining the desired densified sintered body.

Process for preparation of alkaline earth metal aluminosilicate sintered

Disclosed is a liquid-absorbing shaped body comprising a fibrous material and an inorganic powder in which the volume of fine pores having a pore radius less than 0.5.mu. is at least 2.5 cc/g. This shaped body is excellent in the liquid-absorbing capacity and liquid-retaining property to various kinds of liquids.

Liquid-absorbing shaped body

Disclosed is an alkali calcium silicate having two different X-ray diffraction patterns: (1) with diffraction peaks at spacings (d) of 11.8-12.2 A, 6 A and 3 A or (2) with diffraction peaks at spacings (d) of 13.0-13.4 A, 6.7 A and 3.1 A. This silicate is in the fibrous or micaceous form and is valuable as a drying agent or an ion exchange agent. This silicate is prepared by hydrothermal reaction of an aqueous suspension having a specific composition of the starting components.

Alkali calcium silicates and process for preparation thereof

Disclosed is an alkali calcium silicate having two different X-ray diffraction patterns (1) with diffraction peaks at spacings (d) of 11.8-12.2 A, 6 A and 3 A or (2) with diffraction peaks at spacings (d) of 13.0-13.4 A, 6.7 A and 3.1 A. This silicate is in the fibrous or micaceous form and is valuable as a drying agent or an ion exchange agent. This silicate is prepared by hydrothermal reaction of an aqueous suspension having a specific composition of the starting components.

A process for producing calcium silicate of the rational formula 2CaO.3SiO.sub.2.nSiO.sub.2.mH.sub.2 O wherein m is a number of more than 0, and n is a number of 0.1 to 10 from a silicate compound and a calcium compound, which comprises contacting a water-soluble silicate compound with a calcium compound in an aqueous medium, and heating them to a temperature of 150.degree. to 250.degree. C., the amount of the aqueous medium being 5 to 100 times the weight of the calcium silicate obtained, and a process for producing calcium silicate or a calcium silicate-gypsum composite, which comprises adding a water-soluble silicate or its aqueous solution gradually to an aqueous suspension of gypsum, and heating the mixture to a temperature of 150.degree. to 250.degree. C. The calcium silicate and the calcium silicate-gypsum composite, which have a structure composed of an assembly of petal-like flakes, are useful as an adsorbent carrier, a delusterant or a filtration aid.

Growing community of inventors

Shinnanyo, Japan

Genji Taga