Electric melting furnace for ores - where furnace lining exposed to aggressive slags consists of cooled graphite blocks

摘要

The furnace includes electrodes plunged into molten slag; and has an outer metal casing provided with cooling appts. Inside the casing is a sealing layer (a), and then a lining (b) of refractory carbon blocks. At the level of the molten slag, the walls of lining (b) are made of refractory graphite blocks (b1) with a thickness such that the total thermal resistance of layers (a,b1) is 0.0086 to 0.0774 sq.m.deg.C./W. Below blocks (b1), the furnace walls and hearth consist of carbon blocks (b2). The furnace is used mainly for mfg. ferro-alloys, esp. Fe-Ni from oxidised Ni ores. The invention ensures that, even with very high electric power, a solidified protective layer is formed in the slag zong. Aggressive molten slag is kept away from the lining, so the working life of the latter is increased.