Hokkaido Electric Power Company, Inc.

Mitsubishi Jukogyo Kabushiki Kaisha

Babcock-hitachi Kabushiki Kaisha

Tsutomu Ueno

Atsushi Tatani

Shinichiro Kotake

Tsukasa Nishimura

Hiroshi Fujita

Takanori Kuwahara

Tadaaki Mizoguchi

Yutaka Kitayama

Hiroaki Tsuchiai

Satoshi Kudo

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 process for producing a hydrated and cured product of a lime-gypsum-coal ash mixture capable of constituting a high-performance desulfurizing agent, with a high yield and in a simplified manner is provided, which process comprises adding water to a mixture of lime, used desulfurizing agent and coal ash, followed by kneading the resulting mixture, then extruding the resulting kneaded material through a hole of 2 to 10 mm in diameter to obtain bullet-like materials, hydrating and curing said bullet-like materials, followed by drying.

Process for producing hydrated and cured product of lime-gypsum-coal ash

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Sapporo, Japan

Tsutomu Ueno