高硫煤还原磷石膏制SO2

Reduction of phosphogypsum to sulfur dioxide with high sulfur coal

在N2气氛下研究了高硫煤还原磷石膏的热分解反应特性,利用烟气分析仪分析析出的气体成分。研究了不同颗粒尺寸的高硫煤对磷石膏分解的影响,结果表明,高硫煤颗粒尺寸在97—147μm有利于磷石膏分解制SO2的反应。研究还发现原料摩尔比对磷石膏的反应历程有显著的影响,当摩尔比为1∶1.96时,磷石膏还原分解的固体产物有CaS和CaO;当摩尔比降为1∶1.18时,固体产物中CaO大量增加,而仅有少量CaS存在;当摩尔比降到1∶0.98时,固体产物中除了CaO和CaS外,还发现了未反应完的CaSO4。所以摩尔比在1∶1.18时有利于高硫煤还原磷石膏制SO2。

The thermal decomposition reaction characteristic of the reduction of phosphogypsum with high sulfur coal in N2 atmosphere was investigated,and the exhausted gas was analyzed with gas analyzers.The effect of high sulfur coal with different particle sizes on the thermal decomposition of phosphogypsum was also studied.The results show that the coal particles with size of 97-147 μm are conducive to produce more SO2 from the decomposition reaction.The molar ratios of raw material have a notable effect on the reaction process.When molar ratio is 1∶1.96,the products through the reductive decomposition of phosphogypsum are CaS and CaO;when molar ratio decreases to 1∶1.18,CaO in the products increases substantially and only a little CaS exists;when molar ratio decreases to 1∶0.98,besides CaO and CaS contained in the solid product,CaSO4 which is incompletely reacted is discovered.Therefore,the raw material with molar ratio 1∶1.18 is suitable for SO2 production by reductive decomposition of phosphogypsum with high sulfur coal.