Environmental geochemistry of the feed coals and their combustion by-products from two coal-fired power plants in Xinjiang Province, Northwest China

► Geochemical characteristic of feed coal and combustion by-products from power plants. ► High coal quality, low element concentrations in fly ash and low leachable potential. ► S, F, Cl, Hg, and B were highly volatile at ESP in plants. ► High amorphous glass content and SiO2/Al2O3 ratio in the glass matrix of fly ash. ► High potential for a variety of uses of fly ash with low environmental limitations.