GB190004896A - Improvements in the Direct Production of Iron and Steel. - Google Patents

Abstract

4896. Twynam, T. March 15. Basic processes; direct processes; open hearth processes.-Relates to a process for reducing iron ore, oxides, scale, or ferruginous cinder, by means of carbon, during the refining of pig-iron in an open-hearth furnace. Molten pig-iron, or pig-iron and scrap, are charged into an open-hearth, and worked down in the ordinary way with suitable additions of ore and limestone, until a layer of slag, of the requisite depth, has been formed. A mixture of ore or oxide, and carbon, is then added to the charge, together with lime or limestone. When one furnace only is used, a portion of the reduced molten metal is tapped off, and the charge again made up to its original amount by adding a mixture of oxide with carbon, and molten pigiron. Preferably, two or more furnaces are worked in combination, one large furnace being employed for reducing the oxide &c. and the molten metal being run into the other furnaces to be finally purified ; these furnaces may contain partial charges of scrap, or scrap and pig-iron. Magnetic iron sands, magnetically-separated iron ores, or other granular forms of iron ores, may be reduced in the same way.