Influence of Calcination Atmospheres on Thermal Activation of KaoliniteRich Rocks Associated with Coal Measures

The thermal activation experiments of kaoliniterich rocks associated with coal measures (KRC) were conducted in air, nitrogen and carbon dioxide atmospheres, respectively. The thermal decomposition of KRC was studied using thermal analysis, Xray diffraction, infrared spectroscopy and hydrochloride acid leaching methods. The influence of calcination atmospheres on the structure and activity of KRC was discussed. The results showed that the activity of calcined KRC increased with the dehydroxylation and decomposition degree of kaolinite, which was facilitated by the combustion of coal content in air atmosphere. When the calcination temperature exceeded 600 ℃, further transformation of metakaolinite occurred, giving rise to a decline in the activity of calcined KRC, which differed at diverse atmospheres. The transformation from metakaolinite to inert phases was promoted by the combustion of coal content in air atmosphere, whereas was inhibited in carbon dioxide atmosphere.