ABSTRACT
CSF is, as the name indicates, the condensation of oxidized silicon monoxide coming from the gases of silicon or ferro-silicon smelter ovens;
2SiO(g) + O2 = 2SiO2(s) in addition to small dust particles. Thus, the condensation and dust trapped in the filter bags are of very high surface, typically 20,000 m2/kg as measured by N2-adsorption with a spread from 15,000 to 25,000 m2/kg. The individual particles are basically spherical with an average diameter of 0.15 u,m, although usually consisting of primary
aggregates of fused particles. As comparison, the irregular grains of a Portland cement have typical average diameter of 10 |xm. The chemical composition of CSF is rather simple as it usually consists of in excess of 90 per cent SiO2 with a spread from 85 to 99 per cent. The major second oxide is Fe2O3, while the other oxides are normally below 1 per cent each.
