石煤中钒的氧化动力学初步研究

含钒石煤是我国一种新类型钒矿资源,钒的氧化是石煤提钒的基础。本文对钒的氧化动力学作了初步工作,通过试验数据处理结果表明,采用Ерофеев综合动力学公式:描述石煤中钒的氧化过程:2VO_2固+1/2O_2=Y_2O_5固简明可行,较为适宜。 钒氧化反应初期阶段以动力学方式进行:n_1=1,属一级反应过程;继之,n_2=0.2,反应受扩散制约。测定了由动力学过程转换为扩散过程所需的反应时间及其钒氧化率,计算了这两种过程的速率常数和表观活化能。

RESEARCH ON THE KINETICS OF THE OXIDIZING REACTION OF VANADIUM IN STONE COAl

The oxidizing reaction of vanadium is the basic and necessary reaction of extracting vanadium pentoxide from the stone coal. The kinetics for oxidizing of vanadium in the coal has been investigated. From the data of our experiments it is considered that the kinetics of the reaction is successfully described by Epopees comprehensive kinetics equation: Analysis of the results shows that the oxidation reaction 2V02+l/202=V205 occurs in the coal in two steps: kinetics and diffusion. Initially,n = 1, it is a first-order reaction, kinetics-controlled and followed by, n= 0.2, diffusion-controlled reaction. In this paper vanadium oxidizability and transition time from kinetic process to diffusion one have been determined. In the range of 650-800, the rate constant of kinetics K1 and the rate constant of diffusion K2 have been determined. In the processes of oxidizing, the vanadium in the coal, the kinetic activation energies E1 and the diffusion one E2 have been calculated and they are 212.8 KJ.mol-1 and 377. 4KJ.mol-1 respectively.