Particle Size Distribution of Fumes Formed by Ferrosilicon Production

Comparison of Three Real-Time Measurement Methods for Airborne Ultrafine Particles in the Silicon Alloy Industry

“…In Figure 5 (left), the magnification is relatively coarse and the holey carbon film of the sample holder is seen as the egg-shaped hole. The particles collected on the film are agglomerates of different shapes and consist of amorphous silica, very similar to findings reported by others [2,3,24,25]. As seen in Figure 5 (right), with larger magnification, the protoparticles are spheres and the transitions between the smallest protoparticles appear blurred, which indicate that they are undergoing a sintering/coalescing process.…”

“…Both studies characterized the fumes as amorphous silica. Dingsøyr et al [24] and Kolderup [25] reported the characteristics of fumes from the furnace charge top, which may be less relevant a comparison to the tapping fume studied here. All authors emphasize the influence of furnace operation and process parameters on the size and agglomeration status of the PM collected.…”

“…Naess et al [3,22,23] provide detailed descriptions of the PM generation mechanisms for silicon alloys. The metallurgical fume generated in the silicon production industry has been characterized by several authors [2,3,24,25]. The CSF protoparticles are typically amorphous silica spheres which may occur independently but more often as agglomerates.…”

Was there sufficient justification for the 10-fold increase in the TLV for silica fume? A critical review

“…In Limberakis et al's [1986] particle size characterization, the distribution curve of silica fume from the baghouse of a silicon smelter showed a geometric mean for particle diameter of approximately 1.2 µm, placing it in Heyder's [1984] aerodynamic domain with regard to deposition in the respiratory system. This is in contrast to other work in the field which found much smaller mean diameters [Pollicard and Collet, 1954;Kolderup, 1977;Cerchar Industrie, 1979;Aïtcin and Pinsonneault, 1981;Aïtcin et al, 1984;Cunningham, 1992;Cunningham et al, 1996]. The results of a detailed particle sizing analysis of silica fume emitted from a silicon smelter in southern Tasmania indicated that the geometric means of primary particles and aggregates from the baghouse were 0.05 µm and 0.124 µm respectively; primary particles from the taphole were smaller again at 0.034 µm [Cunningham et al, 1996].…”

Airborne Emissions from Si/FeSi Production

“…The characteristics of microsilica have been described in the literature as agglomerates of amorphous silica spheres. 71,87,88 The PM in the silicon alloy industry includes both fine (FP) and ultrafine particles (UFP), i.e. particles with aerodynamic diameters of <2.5 lm and <0.1 lm, respectively.…”