镁热还原法制备无定形硼粉绝热温度的计算与动力学研究  

Calculation of adiabatic temperature and study on knietics of preparation of amorphous boron powder by heating reduction with magnesium

作　　者：伍继君[1] 张广立[1] 郭丽芬[1] 潘波涛[1] 

机构地区：[1]东北大学材料与冶金学院,辽宁沈阳110004

出　　处：《材料与冶金学报》2004年第1期46-50,共5页Journal of Materials and Metallurgy

摘　　要：随B2O3过量系数γ的增加,Mg热还原B2O3反应3Mg(l)+B2O3(l)=3MgO(s)+2B(s)的绝热温度(Tad)降低.当B2O3的过剩系数γ小于1 102时,反应才能以正常的自蔓延方式进行,此时该反应的绝热温度Tad等于1800K.由DTA曲线分析可知,该反应起始反应温度在750～810℃之间,属于液 液反应机制。通过计算可知:反应3Mg(l)+B2O3(l)=3MgO(s)+2B(s)的表观活化能E=18 8kJ·mol-1,反应级数为n=0.7.The adiabatic temperature (T_(ad)) of reaction 3Mg(l)+B_2O_3(l)=3MgO(s)+2B(s) will decrease with the increase of the excess coefficient of B_2O_3 in the thermal reduction of B_2O_3 with magnesium. This reaction can proceed in the way of self-propagating only if the excess coefficient (γ) of B_2O_3 is less than 1.102. Under this condition, the adiabatic temperature (T_(ad)) is 1 800 K. It is known through DTA curve that the beginning temperature of reaction is 750℃, and this reaction belongs to the mechanism of liquid-liquid reaction. It is also known by calculation of reaction 3Mg(l)+B_2O_3(l)=3MgO(s)+2B(s) that the apparent activation energy (E) is 18.8 kJ·mol^(-1), and the reaction order (n) is 0.7.

关 键 词：镁热还原 过量系数 绝热温度 自蔓延 表观活化能 反应级数 

分 类 号：TF123.121[冶金工程—粉末冶金]