Abstract:
A solar reflector soiling study was carried out at a ferromanganese smelter in South Africa to
assess the soiling rates at different locations around the plant. Several meteorological parameters
were monitored to give insight into the conditions that lead to increased soiling. Mineralogical
characterization of dust samples collected from the reflectors and the atmosphere revealed that only
a certain size fraction is of importance with regard to soiling, and that the dust can be attributed to
both raw materials and smelter products. Proximity to the dust source was the primary driver for
increased soiling. The site that experienced the most soiling was very close to raw material heaps;
this was deemed an outlier and was excluded from the summary statistics. The secondary driver
for increased soiling was location relative to the smelter dust sources and the wind’s direction and
speed. The reflector set at the best location experienced 13.1% less soiling than the set at the ‘worst’
(but still feasible) location, represented by an averaged mean daily reflectance loss of 0.0186. The
study revealed that while there are periods of intense soiling at this particular site, proper planning
of reflector location in relation to the smelter dust sources can significantly mitigate the soiling
rate.
