Abstract: Rare earth-transition metal (e.g. iron) scrap (e.g. Nd-Fe-B scrap) is melted to reduce the levels of tramp oxygen and nitrogen impurities therein. The tramp impurities are reduced in the melt by virtue of the reaction of the tramp impurities and the rare earth to form dross on the melt. The purified melt is separated from the dross for reuse. The oxygen and nitrogen of the melt are reduced to levels acceptable for reuse of the treated alloy in the manufacture of end-use articles, such as permanent magnets.

Abstract: Process and apparatus for the rapid efficient melting of solid ferrous metal scrap without direct exposure to water vapor, carbon dioxide, oxygen or oxygen-containing gases, using natural gas and/or other caloric gaseous fuels. The apparatus includes a furnace having a refractory base, means for introducing ferrous metal such as solid steel scrap to the well area, means for providing a slag layer over the solid steel scrap, and gas burner means for emitting one or more forced gas flames for superheating the slag layer to a liquid which covers the scrap and for agitating and circulating the molten slag to form a highly-efficient heat-transfer medium for melting and refining the steel scrap while it is insulated against contact with gases, particularly water vapor, carbon dioxide, oxygen or oxygen-containing gases. The process may operate continuously and can recover heat for scrap preheating, turbine power and other efficient uses.

Abstract: The scrap that is to be charged into an electric arc furnace is preheated by a gas in a closed circuit and this gas is heated in a heat exchanger by the exhaust fumes from the furnace. A minor part of the circulating gas is continuously led off to a burner in which it is burnt with a gas as fuel at such a high temperature that rest products such as dioxines are destroyed. The exhaust fumes from the burner is supplied to the exhaust fumes of the furnace upstream of the heat exchanger. In another burner, another minor part of the circulating gas is continuously burnt with a gas fuel at a substantially lower temperature so that hydrocarbons in the circulating gas burn. The exhaust fumes from the burner are returned to the closed circuit.

Abstract: In a batch production of steel, a charge including solid scrap is loaded into an oxygen steel converter, the scrap is melted and the charge is refined in the converter by means of an oxygen blowing lance inserted into the converter through the converter mouth. To enable larger quantities, i.e. over 30% of scrap to be used, the solid scrap is heated by combustion of fuel in the converter using the oxygen blowing lance whose outlet is, at least initially, below the top level of the scrap in the converter, so that the combustion gases formed by the combustion of the fuel pass upwardly through the scrap.

Abstract: A continuous preheat charging method including the steps of transferring scrap from a receiving point to a discharge point, preheating scrap adjacent the discharge point prior to delivery of preheated scrap to one of a pair of melting furnaces, and alternately feeding preheated scrap to the pair of melting furnaces. A continuous preheat charging system is also disclosed which includes a scrap charge transfer conveyor having a scrap receiving end and a scrap discharge end together with a weigh feeder station at the scrap receiving end and a preheating station at the scrap discharge end. After scrap is weighed at the weigh feeder station and fed to the transfer conveyor, the scrap is preheated at the preheating station and delivered to a furnace feeder station to be fed on an alternating basis to one of a pair of melting furnaces.