| 摘要 |
<p>The invention is a process for steelmaking in a rotary furnace from a solid metallic charge adapted to realize greatly increased heat transfer and melting rates and thereby greater steel production. A hot liquid metal bath is maintained over the length of an oxy-fuel fired rotary furnace. Solid metallic scrap is continually introduced by way of a charge end opening into a melting zone, wherein the bath melting point temperature is depressed on the order of 300 degrees Celsius at the furnace charge end, by means of coincident additions of supplementary carbon into the melt. The effect is a multifold increase in temperature differential between the flame temperature and the temperatures of the furnace walls and charge, with a proportionate increase in the quantity of heat transferred. In order to maintain this depressed temperature, a corresponding increased quantity of cold solid scrap is required to be charged into the melt and advanced along the furnace, according a dramatic production rate increase in relation to the prior art. The preferred embodiment provides an intermediate annular dam which substantially confines unmelted solid charge to the melting zone, over which melted metal overflows into an all-liquid refining and temperature-composition adjustment zone preceding discharge, with overall firing and furnace interior gas flow countercurrent to the general charge movement, thus allowing the steel discharge temperature to be controlled independently of the heating rate. Other benefits include increased refractory life, less oxidation of charge and refractory constituents, and substantially less particulate and pollutants discharged in the process off-gas.</p> |
