Abstract: 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 retentiontends 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%.