ABSTRACT
Condensed silica fume is a by-product of the manufacture of silicon or of various silicon alloys which are produced in so-called "submerged-arc electric furnaces". Condensed silica fume particles appear to be formed by the oxidation and condensation of the gaseous silicon suboxide (SiO), which is formed in the reaction zone. In addition, the chemical composition of quartz and coal, the two major components of the burden of the submerged-electric arc furnace, influences to some extent the chemical composition of condensed silica fume. The type of alloy produced in a given furnace greatly influences the chemical composition of the condensed silica fume recuperated in the bag-house because the temperature and the chemical reactions in the furnace depend on the type and amount of metal alloyed to silicon and on the impurities present in the metal or the ores introduced in the burden.
