Low carbon ferro:chromium prodn. - from chromium mineral using tilting, rotary, oxygen-blown reactor

摘要

Low carbon ferrochromium is produced by (a) charging a tilting rotary reactor with chromium mineral and carbonaceous reductant; (b) heating the charge to at least 1200 deg.C; (c) making successive addns. of solid carbonaceous and oxygen blowing while rotating the reactor in the inclined position to produce a carbon-saturated liq. ferrochromium bath; (d) deslagging and decarburising using an oxygen lance, while the reactor is rotating and inclined, to obtain the desired carbon content of 2-0.2 or even 0.1%; and (e) tapping the reactor. An extra low carbon content of down to 0.020 or even 0.010% can be obtd. by reducing the pressure in the reactor to 0.5-50 (pref. 1-10) torr after step (d) and holding for 5-45 mins. A range of low carbon ferrochromium alloys can be produced, at low cost and high productivity, from low quality minerals and variable quality solid reductants.