利用特制精确控温敞口炉,模拟重病区居民燃烧煤泥饼时氟的排放及控制,分析了停留时间、燃烧温度对氟排放的影响,探讨了CaCO3添加量及燃烧温度与固氟率的关系.结果表明:随着煤泥饼在炉内停留时间的延长,氟的逸出率逐渐增大,1h后氟的排放达到平衡;氟逸出率随温度升高而增加,900℃时逸出率平均为80%,与病区实际燃烧排氟量相吻合;煤泥饼中添加CaCO3能有效控制燃烧氟排放,固氟率随CaCO3添加量的增加而增大,w(CaCO3)为10%时达到最佳固氟效果;500~800℃内固氟率随温度升高而增加,800℃时固氟率最高,平均为44.2%,温度继续升高则固氟率下降,900℃时为25.0%。
A precise temperature regulating open furnace was devised to describe and analyze the regularity and control of fluoride emission from coal-clay briquette combustion in open ground-stove in the serious coal-clay combustion type fluorosis areas, the effect of retention period and combustion temperature on fluorine emission and the relationship of fluorine retention with the dosage of CaCO3 and combustion temperature were obtained. Experimental results indicate that fluorine emission tends to increase with increasing retention period or combustion temperature, and the fluorine emission rate keeps stabile after 1 h. The average fluorine emission rate reaches 80% at 900℃, this is similar to the fluorine emission rate under usual combustion condition. Selecting CaCO3 as calcium-based sorbent can decrease fluoride release from coal-clay briquette combustion effectively, fluorine retention tends to increase with increasing the dosage of CaCO3, and the optimum condition for fluorine retention is blending 10% CaCO3 with coal-clay briquette. Fluorine retention rate tends to increase with increasing combustion temperature from 500 ℃ to 800 ℃, it reaches the highest rate at 800 ℃, and the average fluorine retention rate is 44.2%. But above 800℃, fluorine retention rate declines versus combustion temperature, at 900℃, it reaches 25.0%.