Process for recovery of iron from ore

摘要

Iron ore is first subjected in at least one stage to treatment with a hot reducing gas whereby it is pre-heated and pre-reduced at least partially to lower oxides and possibly to some free iron, and the product is then transferred at a controlled temperature to a second stage wherein the ore is melted and reduced. Hydrocarbon fluid and oxidant are introduced into this second stage, at least a controlled part of the hydrocarbon being introduced directly into the molten ore and the remainder if any being introduced above the surface thereof. The proportion injected into the ore may be controlled according to the concentration therein of free carbon liberated by cracking of the hydrocarbon. The effluent gases from the second stage may form a component of the gas used in the first stage, being mixed with a recirculated part of the first stage effluent, the proportion of the latter being regulated in accordance with the temperature of the product leaving the first stage. During recirculation the carbon dioxide and water vapour content of the gas may be removed; the remainder of the first stage effluent may be used to pre-heat the incoming hydrocarbon and/or oxidant.