Trends in the Distribution of Ash-Forming and Impurity Elements in the Combustion Products of Coals from the Kaa-Khem Deposit

The distribution of ash-forming elements and impurity elements in the ash-and-slag waste (ASW) and fly ash of Kaa-Khem coal was studied by analyzing the enrichment factors of combustion products with the test elements EFiP. Changes in the material composition of coal ash in ash-and-slag wastes from combined heat and power (CHP) plants, boiler houses, and furnaces were considered. It was found that ASW(F) and ASW(CHP) were significantly enriched in Zn, Sb, and Cr (up to a ninefold increase!) in comparison with ASW coal: EFZnASW F = 8.9, EFSbASWF = 6.5, EFCrASWF = 2.9, and EFCrASW (CHP) = 6.3; at the same time, the ASW(B) was enriched in Sb, V, Sr, and Cr within a range of 10-70%, and their EFiB were 1.7, 1.2, and 1.1, respectively. In boiler houses and furnaces, coal burned with large carbon losses, 17 and 10% coke in ASW(B) and ASW(F), respectively; this was due to the secondary carburization of the surface of the ash and slag residue by the thermal destruction products of coal.