Slagging propensities of blended coals

This paper presents the experimental results on the slagging propensity of three pairs of blended coals tested in the Australian Coal Industry Researc h Laboratory furnace. The results showed that none of the coals or blends p roduced strongly molten deposit. At worst, the deposits contained some mode rately sintered material. Most of the blends have (slightly) worse slagging behavior than the component coals. In order to rank the slagging propensit y numerically, we defined the minimum heat flux ratio and total heat flux r atio based on the heat flux profiles. They are better in ranking the slaggi ng propensities than other measures such as the build-up rate and visual ph ysical characteristics. The Fe2O3/CaO molar ratio correlates the slagging p ropensity for five coals and six blends of this study. The worst slagging o ccurs when the ratio approaches 1.0. This ratio provides explanation of why the blends had worse slagging than the component coals for the pairs of bl ends: A-B and C-D. However, we note that there are causes of slagging other than the Fe2O3/CaO molar ratio. (C) 2001 Elsevier Science Ltd. All rights reserved.