Selective Deposition of Calcium- and Iron-Rich Ash Components During Stoker and Pulverised Coal Firing

This paper investigates the contribution of particulate and non-particulate deposition mechanisms to the formation of ash deposition during pulverised coal and stoker coal firing. Using a mass accumulation probe and a BCURA particulate collection cyclone it was possible to demonstrate that deposition results from a number of complex processes. These include enhanced impaction of calcium and iron rich particles, diffusion of alkali metal and zinc salts, and sulphation of high calcium ash.