Mitsubishi Jukogyo Kabushiki Kaisha

Mitsubishi Heavy Industries Limited

Hokkaido Electric Power Company, Inc.

Research Association for Petroleum Alternatives Development

Hiroshi Fujita

Atsushi Tatani

Tetsuya Imai

Koosoo Tao

Mamoru Yokose

Takashi Suzuki

Toru Takashina

Naohiko Ukawa

Masakazu Onizuka

Taku Shimizu

Kenji Inoue

Naruo Yokoyama

Shinichiro Kotake

Mamoru Tamai

Mitsuharu Murakami

Tsuyoshi Ohishi

Yoshio Miyairi

Tsutomu Ueno

Minoru Koikeda

Hiroaki Tsuchiai

Hiroshi Baba

Hideki Kamiyoshi

Ranko Shikai

Koso Tao

Tsutomer Kabumoto

Yutaka Kitayama

A method of treatment of an arsenic sludge obtained from a solid-liquid separation step on arsenic waste water by adjusting the value of pH to 12 or higher by adding a calcium compound is disclosed. The method is characterized by addition of hydrated lime and calcining the sludge.

Method of treating sludge containing arsenic

The present invention provides a process for treating arsenic-containing waste water, comprising adding an oxidizing agent, if necessary, to arsenic-containing waste water to oxidize trivalent arsenic in the waste water into pentavalent arsenic; adding a calcium compound to adjust the pH to 12 or higher; separating it into solid and liquid (first solid/liquid separation); calcining the resulting sludge, while adding a ferric salt to the treated solution to adjust the pH to 6-9 after the solid/liquid separation; and separating it into solid and liquid (second solid/liquid separation). According to the present invention, it is possible to remove arsenic from waste water efficiently to yield treated water satisfying various tolerance limits under various regulations, while the arsenic-containing sludge separated from the waste water can become harmless in subsequent continuous steps.

Process for treating arsenic-containing waste water

A process for removing environmental contaminants from an exhaust gas by a semidry method through contact with an absorbent slurry containing alkaline compounds in a reactor, comprising the steps of adding a material containing calcium sulfate and/or calcium sulfite, a material containing aluminum oxide, and a material containing silicon dioxide to a material capable of supplying calcium oxide, mixing the mixture with water, curing the whole mixture in hot water, and then introducing and dispersing the resulting absorbent slurry in the reactor for contact with the environmental contaminants. In a modification the absorbent slurry is obtained by adding a material capable of supplying aluminum oxide, silicon dioxide, and calcium sulfate and/or calcium sulfite to a material capable of supplying calcium oxide, calcining the mixture at 750.degree.-950.degree. C., mixing the calcined product with water, and curing the mixture in hot water. To the absorbent slurry obtained in either way is added a soluble compound that elevates the boiling point of water.

Process for treatment of exhaust gas

A method of producing solid molding products from a slurry which has undergone absorption in wet-limestone gypsum desulfurization of flue gas includes the steps of concentrating the gypsum-containing absorption slurry, mixing and kneading the solid concentrated slurry with flyash and quicklime or slaked lime, molding the mixture into a given shape using a mold and then curing a resulting molding product in a reaction chamber wherein a part of desulfurized gas is passed. The method also includes solidifying a molded product by drying with water-saturated hot air produced with heat recovered from the flue gas and with water added into a heat recovery process.

Method of producing solid moldings from a by-product of wet

A process for methanol which comprises cracking 100 moles of methanol in admixture with 1 to 99 moles of water, thereby obtaining a gas containing hydrogen and carbon monoxide, is described. The process is preferably carried out using a catalyst which consists of a carrier comprising copper and chromium oxides with or without manganese oxide and/or barium oxide and a catalytic component of nickel oxide or a mixture of nickel oxide and a basic oxide.

Process for reforming methanol

This invention relates to a novel crystalline silicate useful as a catalyst for various organic reactions such as polymerization of organic compounds, alkylation, isomerization, disproportionation and the like, which has a chemical composition represented by the general formula in the terms of mole ratios of oxides under dehydrated state,

Crystalline silicates, and processes for the production or use thereof

A method of desulfurizing exhaust gases by a wet lime-gypsum process comprises the steps of neutralizing a suitable amount of liquid containing impurities separating the neutralized material into solid and liquid phases, heating the separated solid phase to dryness while concentrating the separated liquid phase, mixing the concentrated liquid and dried solid phase in such a manner that the resulting mixture exists as a solid mass containing the impurities, thus making it unnecessary to dispose of any waste liquid.

Method of desulfurizing exhaust gases by wet lime-gypsum process

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Hiroshima, Japan

Hiroshi Fujita