摘要
采用随机过程理论导出了液相在固体颗粒分形介质中的扩散方程 ,得到了分形扩散系数与自由空间扩散系数的关系式 .同时研究了以磷酸与具有丰富内孔隙的磷矿颗粒为代表的液固两相反应的机理和动力学模型 .发现已反应完毕的区段与尚未反应的区段之间的反应界面不是一个面 ,而是一个过渡区段 ,这一反应区段将逐步向颗粒中心移动 .根据固相物质的分形结构与反应机理 ,导出了描述这一过程的理论模型 .
The model of liquid diffusion in a solid fractal medium is developed by adopting random theory, and thus the relationship of diffusion coefficient between fractal medium and free space is obtained. According to the study and analysis of micro-processes,the reaction mechanism and kinetics of liquid-solid phase which feature phosphoric acid and phosphate ore particles system are revealed. When the reactive components diffuse in the ore particle through a large amount of micro pores, there exist three zones, including penetration zone where reaction has finished, reaction zone where reaction and diffusion happen at the same time, and unreacted zone. With the reaction proceeding, the penetration and reaction zone will move towards the center of the particle. From the above basic point of view, the zone and fractal model of two-phase reaction kinetics model has been put forward.
出处
《化工学报》
EI
CAS
CSCD
北大核心
2000年第5期620-625,共6页
CIESC Journal
关键词
分形扩散
磷矿
酸解
液固相反应动力学
fractal diffusion,two phase reaction kinetics,phosphate ore digestion,micro structure of ore particle