Sumitomo Metal Industries, Inc.

Takeyuki Hirata

Hidemasa Nakajima

Shozo Okamura

Seiichi Masuda

Shoji Anezaki

Tohru Matsuo

Katsukiyo Marukawa

Syoji Anezaki

Nobuyoshi Hiroki

Takeo Aoki

Minoru Ueda

Yoshimichi Ohkita

Yasuyuki Tozaki

A process for producing an ultra-low phosphorus steel containing 0.010% or less of phosphorus is disclosed, which comprises charging a desiliconized pig iron into a top- and bottom-blowing oxygen converter, introducing a slag-forming agent in a powdered form onto the molten iron together with the top-blowing oxygen and introducing a bottom-blowing gas selected from the group consisting of an inert gas, nitrogen gas, oxygen gas, carbon monoxide gas, carbon dioxide gas and mixtures thereof during the oxygen top-blowing or during both the oxygen top-blowing and the subsequent tapping.

Production of ultra-low phosphorus steel

In a process for the gasification of solid carbonaceous material such as coal, powdered coal is top-blown onto a molten iron bath stored in a furnace through a non-submerged lance toward a hot spot formed by means of a jet of oxygen and steam top-blown through a non-submerged lance, coal being blown by means of a carrier gas, and flux is optionally added into the furnace by the lump or blown toward the hot spot, thereby the coal being gasified. The ratio L/L.sub.o of the depression depth L of the molten iron bath to the molten iron bath depth L.sub.o is maintained from 0.05 to 0.15, and the blowing velocity of the solid carbonaceous material is maintained from 50 to 300 m/sec so as to suppress the forming of an adhered mass in the furnace. A stirring gas is blown through a bottom nozzle to stir the molten iron bath.

Gasification process of solid carbonaceous material

A process and apparatus for making steel in a basic oxygen furnace by the top-blowing of pure oxygen and the bottom-blowing of a gas mainly composed of carbon dioxide are disclosed, in which a waste gas discharged from said basic oxygen furnace is utilized as the only source of the gas to be blown into a molten metal.

Steel making process and apparatus

An oxygen top-blowing steelmaking process is disclosed, which comprises preparing a molten metal suitable for producing steel in a basic oxygen furnace, carrying out the top-blowing and bottom-blowing and then tapping the resulting molten steel. The bottom-blowing is carried out at least partly during the period of time from beginning of blowing to the tapping of the melt and a powder of a slag-forming agent, such as quick lime, limestone, is introduced into the molten metal together with the top-blowing of oxygen jet injected through an oxygen lance so as to form an effective slag at an early stage of refining.

Steel making process

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Ibaraki, Japan

Takeyuki Hirata