轻烧菱镁石对生球爆裂温度的影响

Effect of Calcinated Magnesite on Burst Temperature of Green Pellet

在850℃条件下,对菱镁石进行焙烧、磨细处理后获得轻烧菱镁石粉末.将该粉体作为黏结剂用于球团矿生产,研究考察了轻烧菱镁石对生球爆裂温度的影响.结果表明,随着轻烧菱镁石质量分数的增加,生球爆裂温度逐渐增大,当轻烧菱镁石质量分数由0增至2.0%时,爆裂温度最大增幅可达200℃.主要原因如下:由于该黏结剂的加入,生球内部水分蒸发速率减小,生球内部产生的蒸汽压相对较小,同时,该黏结剂可使生球在干燥过程强度迅速提升,这使得生球爆裂温度逐渐增大.

The powder of calcinated magnesite was obtained by calcinating （850 ~C） and grinding process. The power was utilized as a binding additive to produce green pellets. The effect of the calcinated magnesite on the burst temperature of the green pellets was investigated. The results showed that the burst temperature of the green pellets increased gradually with the increase of the mass fraction of the calcinated magnesite in the green pellets. When the mass fraction of the calcinated magnesite increased from 0% to 2. 0% , the largest increase of the burst temperature was up to 200 ~C. The main reasons were as follows：with the addition of the binding additive （calcinated magnesite）, the speed of water-evaporation within the green pellets decreased which led the vapor pressure of inside the green pellets to be relatively small, and the strength of the green pellets increased rapidly in the drying process, which lead the burst temperature of the green pellets increased gradually.