Other

Jfe Steel Corporation

Nkk Corporation

Nippon Rotary Nozzle Co., Ltd.

Yamakawa Sangyo Co., Ltd.

Manabu Tano

Takeshi Ishii

Hideto Takasugi

Akira Shirayama

Hirohisa Nakashima

Naoki Kikuchi

Yuichi Uchida

Ryo Kawabata

Kazuhito Yamamoto

Naotaka Sasaki

Shizuhiko Ikeno

Yasushi Ogasawara

Masanori Nishikori

Yozo Iwaki

Futoshi Ogasawara

Masaomi Senoo

Hironori Fukushima

Shinichi Akai

Norihiko Suzuki

Akira Ohashi

Kotaro Tanaka

Jun Ayama

Kochiro Ejima

There is proposed a method for preliminary treatment of molten iron wherein heat source for dissolving scrap is ensured sufficiently to improve iron yield while decreasing phosphorus concentration efficiently by suppressing the amount of flux solvent used in the process of desiliconization, dephosphorization and decarburization. In the method for preliminary treatment of molten iron by conducting desiliconization and dephosphorization of molten iron with a converter type container, molten iron is first charged into the converter type container to conduct desiliconization and then intermediate slag removal is conducted, and subsequently a lime-based flux solvent is added to the container while blowing oxygen to conduct dephosphorization of the molten iron, and thereafter newly untreated molten iron is charged into the container to conduct desiliconization, and subsequently the above treatments are repeatedly conducted with the same container.

Method for preliminary treatment of molten iron

A filler sand for a ladle tap hole valve contains 70 to 90 wt % of chromite sand and 10 to 30 wt % of silica sand and is blended externally with 0.05 to 5 wt % of carbon black calculated based on the total amount of the chromite sand and the silica sand; or contains 70 to 90 wt % of chromite sand and 10 to 30 wt % of silica sand, wherein the chromite sand has a particle diameter distribution such that 99% or more of the chromite sand consists of particles having diameters ranging from 150 to 850 &mgr;m and that 95% or more of the chromite sand consists of particles having diameters ranging from 200 to 600 &mgr;m, and the silica sand has a particle diameter distribution such that 95% or more of the silica sand consists of particles having diameters ranging from 150 to 850 &mgr;m and that 80% or more of the silica sand consists of particles having diameters ranging from 200 to 600 &mgr;m.

Filler sand for a ladle tap hole valve

Sliding nozzle filler

Growing community of inventors

Fukuyama, Japan

Manabu Tano