Direct steel making from pre-reduced matls - efficiently producing high quality clean steel in simplified process

摘要

High quality steel is obtd by (a) obtg. an Fe-rich starting matl. (I) by direct redn of ore, (b) melting and final redn. of (I) in an electric furnace, pref. using heat conserved in (I) at the end of (a), (c) transferring the melt to an adjustable vacuum treatment ladle, opt. with supply of heat during vacuum treatment and/or injection of inert and/or reactive and/or cooling gases or vapours into the melt during vacuum treatment, and (d) casting the finished steel directly from the treatment ladle. Process reduces amt of slag, avoids need for sintering ore particles, gives a high (90%) redn rate; avoids needs for forming sponge iron lumps and reduces power consumption and furnace passage time.