Nippon Steel Corporation

Satomi Yamamoto

Masataka Yoshii

Teruo Matsuo

Teruo Yokoozi

A molten iron is continuously refined in a refining vessel of a closed type using a flux composed chiefly of an alkali metal compound so as to decrease the content of P and S to a low level. The alkali metal compound is recovered from the evaporating material and slag generated in the refining and is again used in the refining, while such valuable elements as P, V, etc. may be recovered. The molten iron thus refined can be converted into a steel of high quality in a known oxygen steel making furnace substantially by means of decarburization only and without the use of any flux or with a slight amount thereof. The practice of this invention makes it possible to substantially obviate a substance to be discarded or rejected in the steel making process.

Method for continuous refining of a molten iron base metal

A method for refining a molten steel in vacuum, which comprises blowing a non-oxidizing gas or a non-oxidizing gas together with an oxidizing gas into a bath of the molten steel in a refining vessel of a R-H vacuum degassing apparatus at a position between the bath surface and a bath depth of 50 cm (inclusive) from the bath surface in an almost horizontal direction.

Growing community of inventors

Kitakyushu, Japan

Satomi Yamamoto