砖坯烧制过程中氟逸出特性研究

采用杭嘉湖地区的2种典型制砖粘土及富石灰的紫红壤为原料,通过实验室模拟试验和砖瓦厂现场测定研究了制砖中氟的逸出特性。结果表明：氟在粘土矿物发生脱羟基作用时开始逸出,温度约为600℃,主要逸出发生在约800℃至砖坯发生明显烧结时的范围内,砖瓦窑内存在可使氟逸出量减少的氟循环现象;制砖粘土性质及工艺对氟逸出存在较大影响,CaO含量高的粘土氟逸出量明显较少;中适量钙基物料、烧结料及改进制砖工艺可抑制氟的逸出。

Fluorine Emission in Firing Bricks Process

The firing tests with clay blocks have been carried out to study the behavior of fluorine emission during brick-making. The results indicated that fluorine emission starting during the periods of dehydroxylation of clays, i.e., approx. 600!, and the main portion occurred in the range of approx. 800! up to the pronounced sintering range of clay. In brick kiln, the fluorine circuit occurred, which could reduce fluorine emission. There was a significant effect of the properties of clay and the technology of brick-making on fluorine emission, in which the lime-rich clays evolved less fluorine, and the fluorine emission would reduce by additives of calcium-based material or sintering aids, and improving brick-making technology. These results provided the basis for fluoride emission control in brick-making practice.