The Institute of Gas Technology has developed afluidized-bed process for recovering direct reduced iron fromblast furnace flue dust-a material currently considered to be awaste from the iron and steel industry. In the process, a portionof the carbon in the flue dust is combusted to supply energy forthe endothermic reaction between carbon and steam. Thereaction produces reducing gases comprised of carbonmonoxide and hydrogen both of which react with iron oxides toproduce reduced iron. Up to 95 percent of the iron oxidescontained in the waste stream can be reduced to elemental iron.The vitiated reducing gases emanating from the process can beused as fuel in the plant. The yield of iron depends upon thequantity of iron oxide present in the flue dust and generallyranges from 20 to 30 percent of the waste stream. 'be Theinvestment cost estimated for a single processing train dedicatedto one steel plant can be recovered in less than one year.
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