Method of making high density, fusion cast basic metallurgical

Abstract

A novel method of making a refractory material is disclosed comprising the steps of providing an electrical arc metal furnace, charging that furnace with a charge of refractory oxide, and selecting voltage, amperage and electrode spacings to create novel 'hum and scum' melt conditions. This hum and scum condition is maintained until said charge is substantially melted. The described technique is particularly useful for melting magnesia chrome materials to produce fusion cast refractory products which are highly reduced and quite dense. The elaboration of this product requires higher energy input per pound concurrent with an increased consumption of reducing materials compared with standard preparation conditions. The resulting product exhibits higher oxidation weight gains, higher densities, lower porosities, high cold crush strengths, more thermal shock resistance, and better corrosion-erosion resistance than similar magnesia chrome refractory products fused using prior 'arc and bark' processes.