金属粉末还原中的冶金反应工程学探讨

Primary investigation of metallurgical reaction engineering in metal powder reduction process

就冶金反应工程学中的质量传输及化学反应在金属粉末还原过程中的应用进行了初步探讨。指出:气-固反应是常见的金属粉末还原反应之一;常用的还原设备,如管式电炉,可看成活塞流反应器,并用活塞流反应器的物质恒算方程来描述;气固间的对流传质可用舍伍德数、雷诺准数和施密特数的组合来表征,固相内气体扩散的质量通量是孔隙率、孔的曲折度、有效扩散系数和浓度梯度的函数,固相内的气固反应可用缩小的未反应核模型来描述;粉末物料的还原程度取决于固体内的气体扩散及气固反应,哪一个过程进行得最慢,则该过程就是全过程的控制环节。

An accidence investigation on the application of mass transport and chemical reaction of the metallurgical reaction engineering in reduction processes of metal powder was carried out in the present paper.And the follows were pointed out that,gas-solid reaction is one of the usual metal powder reduction;the usual reductive equipment is the electric tublar furnace,which is characterized by piston flowing reactor and accommodates to the law of matter conservation when calculating;the convection transfer of mass between gas and solid can be charactered by the combination of Sherwood,Reynolds and Schmidt figures,the mass flux of gaseous diffusion in solid phase is a function of porosity factor,labyrinthic rate,effective diffused rate and concentration gradient,and the gas-solid reaction in solid phase as well can be described by model of shrunken unreacted core;the reduced degree of powder's material depends on the gaseous diffusion and gas-solid reaction in solid phase,the slowest course is the control course of the entire process.