Nippon Steel Corporation

Japan Metals & Chemicals Co., Ltd.

Tuneyuki Inoue

Hiroyuki Katayama

Hidetake Ishikawa

Chikara Saito

Masatoshi Kuwabara

Masaki Fujita

A process which enables high-chromium alloy such as ferrochromium heretofore obtained by the use of electricity to be produced less expensively in higher yield of chromium by the smelting reduction using solid carbonaceous material such as coke in the place of electricity. The process of smelting reduction is so performed in the top and bottom blowing converter divided into two stages: the first stage for carrying out the converter operation under continued supply of the raw materials containing pre-reduced chromium oxide (chromium ore) and the second stage for carrying out the converter operation under suspended supply of the raw materials containing the pre-reduced chromium oxide, and the first stage of converter operation is carried out under conditions such that the temperature of the molten metal remains at or below 1,650.degree. C. and the ratio of the volume of the gas generated per minute by the substances supplied through the tuyere for bottom blowing to the combined weight of the molten metal and the molten slag falls in the range of 100 to 2,500 [Nl/min.t] and the second stage of converter operation is carried out under conditions such that the temperature of the molten metal remains at or below 1,650.degree. C., the ratio of the volume of gas generated per minute by the substances supplied through the tuyere for bottom blowing to the combined weight of the molten metal and the molten slag falls in the range of 100 to 1,800 [Nl/min.t].

Growing community of inventors

Fukuoka-ken, Japan

Tuneyuki Inoue