A rapid water-cooling process to desulfurize high temperature CFB bottom ash was designed for the improvement of poor ash utilization. Apparatus and methods for bench-scale rapid water-cooling and desulfurizing study were established and CFB ashes with and without treatment were characterized for f-CaO content

microscopic structure

and desulfurization efficiency. Through theoretical analysis

a hypothesis

that rapid water-cooling could facilitate destroying shell of CaSO4 particles

was proposed and validated experimentally. Results of SEM/EDX and TGA analyses on treated and non-treated ashes showed that calcium on particle surface increased evidently and the calcium recycling rate could increase about 30% post water-cooling treatment. The desulfurization efficiency enhanced continuously with increasing temperature of CFB bottom ash before rapid water-cooling. When hot CFB ash entered into water

ash particles could burst and destroy CaSO4 shell due to strong thermal stress across particle surface. Since higher temperature of CFB ash prior to water-cooling would result in stronger thermal stress

CaSO4 shell were destroyed more easily and desulfurization efficiency became higher. Thus

the rapid water-cooling process would be a new method for regeneration and reuse of CFB ash by improving desulfurization efficiency

which certainly provided practical guidance for engineering applications.