Kobe Steel, Ltd.

Noriaki Mizutani

Koji Tokuda

Masahiko Tetsumoto

Osamu Tsuge

Takeshi Yamashita

Katsuya Akiyama

Yutaka Miyakawa

An exhaust gas duct apparatus for use in a rotary-hearth furnace for heating a starting material including a carbonaceous reducing material and an iron-oxide containing material to produce reduced iron or granular metallic iron. In an exhaust gas duct for use in the rotary-hearth furnace, a cooling part for cooling an exhaust gas discharged from the rotary-hearth furnace to solidify a metal salt in the exhaust gas, a collision part for allowing the exhaust gas just after being cooled to collide therewith to drop down the metal salt solidified, and a direction change duct for guiding the exhaust gas after being collided, in a direction other than a direction of dropping the metal salt, are arranged in this order in two stages.

Rotary hearth furnace exhaust gas duct apparatus and method for operating same

This method for removing nitrogen oxides brings exhaust gas containing oxygen and at least one nitrogen oxide selected from the group consisting of nitrogen monoxide and nitrogen dioxide into contact with ammonia without the presence of a catalyst, for at least 0.5 seconds under a temperature of no less than 900 DEG C., and breaks down the nitrogen oxide. According to this method, it is possible to remove nitrogen oxides in a highly efficient manner and significantly reduce the amount of unreacted ammonia.

Method for removing nitrogen oxides

An object of the present invention is to produce briquettes that have high strength even when the amounts of binder and water used are decreased as much as possible. A method for producing briquettes that achieve this object includes a step of forming primary granules by using a powder containing a metal oxide and at least one of zinc oxide, lead oxide, and titanium oxide and a step of compressing the primary granules still containing the at least one of zinc oxide, lead oxide, and titanium oxide so as to mold the primary granules into secondary granules.

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Kobe, Japan

Noriaki Mizutani