Iron oxide melt reduction furnace and method

Abstract

An iron oxide melt reduction furnace has a hearth with a raised periphery forming an annular shelf, the hearth holding a carbonaceous iron melt up to a level forming a thin layer on the shelf. The furnace side wall extends upwardly from the periphery of the hearth's shelf, and means are provided for feeding material containing iron oxide to the melt at a location inside of the shelf, for reduction of the oxide by the melt's carbon. Means are provided for feeding solid steel scrap to the hearth's shelf and the shallow melt layer thereon so as to maintain on the shelf an annular pile of the scrap sloping downwardly from the furnace side wall to the inner periphery of the shelf. The scrap, inherently of lower carbon content than the carbonaceous iron melt, adulterates and thereby lowers the carbon content of that shallow layer, this raising the melting temperature of the shallow layer while reducing its temperature, thus forming adjacent to the furnace's side wall a relatively low-temperature mixture that is partially solid and partially liquid metal, which together with the scrap between that mixture and the inner periphery of the shelf, protects the side wall lining from the destructive attack that otherwise occurs when it is contacted by the upper level of the melt and the slag formed by the reduction of the oxide and floating on the melt.