Nippon Chemical Industrial Co., Ltd.

Other

Ebara Corporation

Yutaka Kinose

Shinsuke Miyabe

Takeshi Sakamoto

Toru Hata

Takahiro Nagayama

Eriko Okuno

Masahiro Kikuchi

Akinori Inoue

Makoto Komatsu

Takeshi Izumi

Takashi Sakuma

Kenji Tsuge

Kiyoshi Satou

Hiroshi Chihara

Mari Tokutake

Kaori Sugihara

Takahiro Nishita

Kenta Kozasu

Ryohei Imamura

Hiroyoshi Aikawa

Eiji Noguchi

Yoshikazu Watanabe

Mari Aikawa

An adsorbent capable of adsorbing radioactive antimony, radioactive iodine and radioactive ruthenium, the adsorbent containing cerium(IV) hydroxide in a particle or granular form having a particle size of 250 &#x3bc;m or more and 1200 &#x3bc;m or less; and a treatment method of radioactive waste water containing radioactive antimony, radioactive iodine and radioactive ruthenium, the treatment method comprising passing the radioactive waste water containing radioactive antimony, radioactive iodine and radioactive ruthenium through an adsorption column packed with the adsorbent, to adsorb the radioactive antimony, radioactive iodine and radioactive ruthenium on the adsorbent, wherein the absorbent is packed to a height of 10 cm or more and 300 cm or less of the adsorption column, and wherein the radioactive waste water is passed through the adsorption column at a linear velocity (LV) of 1 m/h or more and 40 m/h or less and a space velocity (SV) of 200 hor less.

Adsorbent for radioactive antimony, radioactive iodine and radioactive ruthenium, and treatment method of radioactive waste water using the adsorbent

The present invention provides solidified radioactive waste into which a titanium-containing adsorbent having a radioactive element adsorbed thereto is vitrified, the solidified radioactive waste being capable of confining a large amount of the titanium-containing adsorbent having a radioactive element adsorbed thereto, and furthermore elution of the radioactive element from the vitrified waste being suppressed. The method of the present application includes a step of heat-melting a mixture that includes a titanium-containing adsorbent having a radioactive element adsorbed thereto, a SiOsource, and an MO source (M represents an alkali metal element) to form vitrified waste. The titanium-containing adsorbent is preferably one or two or more kind such as silicotitanate, an alkali nonatitanate, and titanium hydroxide.

Method for producing solidified radioactive waste

There are provided an adsorbent material excellent in the adsorptive removal properties of Cs and Sr also in seawater, and a method for producing a crystalline silicotitanate suitable for the adsorbent material. The adsorbent material according to the present invention comprises: at least one selected from crystalline silicotitanates represented by NaTiSiO.nHO, (NaK)TiSiO.nHO and KTiSiO.nHO wherein x represents a number of more than 0 and less than 1 and n represents a number of 0 to 8; and at least one selected from titanate salts represented by NaTiO.mHO, (NaK)TiO.mHO and KTiO.mHO wherein y represents a number of more than 0 and less than 1 and m represents a number of 0 to 10. The adsorbent material is suitably produced by a method for producing a crystalline silicotitanate in which a silicic acid source, a sodium compound and/or a potassium compound, titanium tetrachloride, and water are mixed to obtain a mixed gel, and the mixed gel is subjected to a hydrothermal reaction.

Adsorbent material and method for producing crystalline silicotitanate

There is provided an adsorbent material having adsorptive removal properties of Cs and Sr in seawater, and a method for producing a crystalline silicotitanate suitable for the adsorbent material. The adsorbent material includes one selected from crystalline silicotitanates represented by NaTiSiO.nHO, (NaK)TiSiO.nHO and KTiSiO.nHO wherein x represents a number of more than 0 and less than 1 and n represents a number of 0 to 8; and one selected from titanate salts represented by NaTiO.mHO, (NaK)TiO.mHO and KTiO.mHO wherein y represents a number of more than 0 and less than 1 and m represents a number of 0 to 10. The adsorbent material is produced by a method for producing a crystalline silicotitanate in which a silicic acid source, a sodium compound and/or a potassium compound, titanium tetrachloride, and water are mixed to obtain a mixed gel, and the mixed gel is subjected to a hydrothermal reaction.

Provided is a method for preparing high-purity elemental phosphorus capable of simultaneously reducing both arsenic and antimony from crude white phosphorus containing a great amount of arsenic and antimony as impurities. Provided is a method for preparing high-purity elemental phosphorus, the method including bringing liquid crude white phosphorus into contact with an iodic acid-containing compound selected from iodic acid and iodates in an aqueous solvent in the presence of a chelating agent, wherein the chelating agent is selected from polyvalent carboxylic acids, polyvalent carboxylates, phosphonic acid and phosphonates.

Method for preparing high-purity elemental phosphorus and method for preparing high-purity phosphoric acid

An aqueous zinc nitrite solution which contains substantially no calcium (Ca) ions is provided, in which, in terms of the aqueous zinc nitrite [Zn(NO)] solution having an NOconcentration of 10% by weight, the sodium (Na) ion concentration is 200 to 2000 ppm and the sulfate (SO) ion concentration is 20 ppm or less in the solution. The aqueous zinc nitrite solution can be prepared by providing a zinc compound and an alkali nitrite as raw materials and subjecting the raw materials to electrolytic synthesis through a double decomposition reaction using an ion-exchange membrane as a diaphragm. As the aqueous zinc nitrite solution is provided, an extremely efficient metal surface treatment is made possible which has a reduced amount of sodium ions. In particular, it contains substantially no sulfate ions and no calcium ions.

Aqueous solution of zinc nitrite and method for production thereof

The present invention provides a decolorized red phosphorus composition capable of inhibiting coloring in dark red peculiar to red phosphorus even when kneaded with a resin or the like, modified red phosphorus used for the decolorized red phosphorus composition and a production method therefor, and a flame-retardant polymer composition using the decolorized red phosphorus composition. The modified red phosphorus includes red phosphorus particles (A) whose surfaces are coated with a modified resin film (F) containing white particles (B) having a whiteness of 70 or more, color particles (C) having a hue H of 30 to 80 in the Munsell color-system hue circle, and a binder resin (D). The decolorized red phosphorus composition includes a mixed powder containing the modified red phosphorus and white particles (B) having a whiteness of 70 or more. The flame-retardant polymer composition contains the decolorized red phosphorus composition and a polymer compound (I).

Modified red phosphorus, method of producing the same, decolorized red phosphorus composition and flame-retardant polymer composition

The red phosphorus base flame retardant for an epoxy resin is provided, which has red phosphorus particles coated with a thermosetting resin containing an anhydrous zinc compound. The coated red phosphorus has properties that a slurry having the coated red phosphorus dispersed in 10% by weight into water at 20&#xb0; C. has an electric conductivity of 30 &#x3bc;s/cm or below, the slurry having been left standing at 80&#xb0; C. for 20 hours has an electric conductivity of 150 &#x3bc;s/cm or below, and when 80 ml of water is added to 8 g of the coated red phosphorus and heated at 80&#xb0; C. for 20 hours, a concentration of POions eluted is 10 ppm or below.

RED PHOSPHORUS-BASE FLAME RETARDANT FOR EPOXY RESINS, RED PHOSPHORUS-BASE FLAME RETARDANT COMPOSITIONS THEREFOR, PROCESSES FOR THE PRODUCTION OF BOTH, EPOXY RESIN COMPOSITIONS FOR SEALING FOR SEMICONDUCTOR DEVICES, SEALANTS AND SEMICONDUCTOR DEVICES

An aqueous zinc nitrite solution contains as impurities 10 ppm or less of sodium (Na) and 100 ppm or less of sulfate ions (SO ) when the aqueous solution has a concentration of zinc nitrite &lsqb;Zn(NO ) &rsqb; of 10% by weight in terms of NO . Also, disclosed is a method for preparing an aqueous zinc nitrite solution, including a first step of reacting zinc sulfate with calcium nitrite to form an aqueous zinc nitrite solution and a second step of purifying the aqueous zinc nitrite solution.

Aqueous zinc nitrite solution and method for preparing the same

This invention provides a metal surface-treating method which comprises a chemical conversion step of dipping a substrate in an acidic aqueous zinc phosphate solution, and using an aqueous zinc nitrite solution as an accelerator, said aqueous zinc nitrite solution being substantially free of calcium ion and containing 0 to 6500 ppm of sodium ion and 0 to 20 ppm of sulfate ion in case of assuming the concentration of zinc nitrite &lsqb;Zn(NO ) &rsqb; therein to be 10 weight % as NO .

Metal surface-treating method

The fine spherical silica having a particle size distribution in which maximum particle diameter is 24 &mgr;m, average particle diameter is 1.7 to 7 &mgr;m, and the proportion X of particles having a particle diameter of 3 &mgr;m or less in the total particles is 100/D to (18&plus;100/D ) wt %, and the viscosity at 50&deg; C. of a mixture obtained by blending a maximum of 80 wt % of the fine spherical silica with a liquid epoxy resin or silicone resin at room temperature is 20 Pa&middot;s or less is provided. The spherical silica is useful as a filler for sealing resin composition which has excellent gap permeability and seals slight gaps, between a substrate and an IC chip and has high reliability.

Fine spherical silica and liquid sealing resin composition containing same

The present invention relates to a fused spherical silica having a maximum particle size of 45 &mgr;m, an average particle size of 2 to 10 &mgr;m, and a ratio of a specific surface area S of the particles to a theoretical specific surface area S of the particles, S /S , of 1.0 to 2.5, the surface of the particles being smooth. The present invention can provide a liquid sealing resin composition having sufficiently low viscosity for sealing a slight gap between a substrate and an IC chip and also having high reliability, and a fused spherical silica filler to be filled therein.

Fused spherical silica, method for producing same and liquid sealing resin composition

The present invention relates to fused spherical silica for liquid sealant which has a particle size distribution such that maximum particle size is 24 &mgr;m, average particle size is 2 to 7 &mgr;m, and the proportion of particles having a particle size of 1 &mgr;m or less is 1% by weight or less, and the silica has a BET specific surface area of 3 m,/g or less. Fused spherical silica filler of the present invention for liquid sealant can be blended with an epoxy resin or silicone resin which is liquid at normal temperature in high proportion, and can minimize the coefficient of linear expansion of a liquid sealing resin composition.

Growing community of inventors

Tokyo, Japan

Yutaka Kinose