拌煤黏土对昭通地区燃煤氟污染的影响

Effect of Clay on Coal-Combustion Fluorine Pollution in Zhaotong

运用离子选择电极（ISE）法和固相平衡法对昭通地区农户常用煤炭、拌煤黏土、煤泥等物质的氟含量、燃烧时的氟释放率、以及它们与燃煤氟污染间的关系进行了研究.结果表明：“煤泥”燃烧氟释放率、氟释放量都要大于块煤.制作煤泥的拌煤黏土是昭通地区“燃煤”氟污染的一个重要污染源.氟质量分数为640×10^-6左右的拌煤黏土,对昭通氟中毒区“燃煤”氟污染物排放的“贡献率”介于40%～60%之间.单纯使用氟质量分数为50×10^-6左右的低氟块煤,仍会对烘烤粮食造成超过卫生标准的氟污染,但这种污染程度已大大小于块煤和＂煤泥＂联用烘烤对粮食的氟污染.

The fluorine content, emission rate of coal, clay, mixed coal and clay used by peasant households, and the relation between them and fluorine pollution in Zhaotong of Yunnan province have been studied by using an ion selective electrode （ISE） and solidoid balance methods. The results show that the fluorine emission rate, capacity of mixed coal and clay are higher than that of block coal; the clay as a binder for fine coal is one important source of fluorine pollution caused by coal-combustion in Zhaotong. When the fluorine content of the clay is about 640 mg/kg, iUs fluorine emission amount is about 40--60 percent of all the fluorine emis- sion amount generated by coal-combustion. Only using the block coal which fluorine content is about 50 mg/kg to dry corn, it also could result in the fluorine pollution to corn, and the fluorine content of the corn after dried is beyond the tolerance limits of fluorine in food. But the fluorine pollution to the corn caused by only using block coal to dry corn is less than that caused by using block coal, mixed coal and clay to dry corn.