Synthesis of Al-substituted 11A Tobermorite from Aegirine-augite Syenite Potash Ores by Hydrothermal Reaction at 300℃

摘要

The Al-substituted 11A tobermorite was synthesized from aegirine-augite syenite potash ores by alkaline hydrothermal reaction at 300℃. The obtained tobermorite was characterized by chemical analysis, X-ray diffraction and scanning electron microscopy. The effect of reaction time on the tobermorite formation and the dissolution ratio of the K_2O in the potash ores were investigated. It was revealed that the dislocation ratio of K_2O increases with increasing reaction time. The main rock constituents were converted into a well-crystallized Al-substituted 11A tobermorite after 3 hours hydrothermal reaction at 300℃. The obtained Al-substituted tobermorite forms hollow spherical aggregates with the diameter of 40μm-80μm by the crossing of fibrous tobermorite crystal together. The Al~(3+) may substitute isomorphously up to 15 at % of Si~(4+) in the obtained tobermorite.