Performance patterns of high-calcium (basic) ashes from thermal power plants of Kansk-Achinsk Basin coals

Ashes from thermal power plants (TPPs) produced by the high-temperature combustion of brown coal in the Kansk-Achinsk Basin (KAB) were examined. Chemical composition fields for high-calcium (basic) ashes from coals in the main KAB open-pit mines were determined across a wide range of parameters using 278 samples. The phase composition of the ashes was determined using the results of a rational chemical analysis (RCA) of five individual ash samples within a basicity range of 0.98–2.62, according to the quality factor. The content of all crystalline phases grows with increasing ash basicity due to a decrease in the proportion of aluminosilicate glass phase. The mass fraction of acid-soluble silica in the ash, as well as the amount of monomer [SiO₄] and dimer [Si₂O₇], increase proportionally to its basicity. The C₂S content in the ash, calculated from the amount of silica monomer, is lower than that calculated using X-ray chromatography data.