氟磷灰石高温热分解特性与机理

Study on pyrolysis and kinetics of fluorine emission of fluorapatite at high temperature

煤中含氟矿物热分解行为的研究是燃煤氟析出机理的重要比照研究方法.在固定床反应器上采用气态氟化物直接吸收方法首次系统研究煤中主要含氟矿物氟磷灰石热分解特性与动力学机理.结果表明,高温条件下氟磷灰石热分解率随加热温度、加热时间的增加而增加,空气中水蒸气含量对分解率有显著影响.动力学计算表明,在800～1200℃温度范围内,氟磷灰石热分解反应为一级反应,反应活化能E＝77±1kJ/mol,频率因子A＝7.4±0.5min-1.研究结果对燃煤氟析出特性与机理研究具有指导意义,对磷肥工业氟析出机理与控制也具参考价值.

The study on pyrolysis behavior of fluorine minerals in coal is an important research method for fluorine emission during coals combustion. In the paper, the fluorine pyrolysis characteristics and kinetics mechanics of fluorapatite mineral at elevated temperatures were studied systemically for the first time by gaseous fluorides direct absorption and fluoride ion-selective electrode measurement technique. The research results have shown that the heating temperature, heating time and air moisture have remarkable effect on the pyrolysis rate of fluorapatite mineral. Kinetics calculation has shown that pyrolysis reaction was first order and the activation energy for the pyrolysis was 77±1kJ/mol, applicable over the range 800~1200℃.The research results will be of significance for fluorine emission mechanism, control technology during coal combustion and phosphoric fertilizer production process.