摘要
为确定轻烧氧化镁浸取过程的最优控制参数,采用硫酸铵作为浸取剂,考察了浸取体系温度、硫酸铵初始浓度以及轻烧氧化镁颗粒粒度对浸取反应动力学的影响,并得到了宏观反应动力学方程式。结果表明:在一定的浸取剂初始浓度和固体反应颗粒粒度范围内,该浸取反应过程符合Crank-Kinstelin-Browhetein模型;表观反应活化能为57.41kJ/mol,属表面化学反应控制类型。当硫酸铵与氧化镁初始物质的量之比大于2时,反应过程逐渐由Crank-Kin-stelin-Browhetein模型向减缩核模型过渡。当轻烧氧化镁颗粒初始粒度较大时,浸取反应过程也呈现上述过渡趋势。
The kinetics of leaching lightly calcined magnesia was investigated to obtain the optimal control parameters for the leaching process. The effects of system temperature, initial (NH4)2SO4 concentration, and MgO particle size on the reaction rate were determined. A kinetics equation developed from the data agreed well with the CrankKinstelinBrowhetein Model for selected initial (NH4)2SO4 concentrations and MgO particle sizes. The apparent activation energy was 57.41 kJ/mol which indicates that the leaching process is controlled by the surface chemical reaction. When the initial mole ratio of (NH4)2SO4 to MgO is greater than 2, the equation departs from the CrankKinstelinBrowhetein Model, but tends to fit the CoreShrinking Model. This tendency also occurs when the leaching process starts with larger MgO particles.
出处
《清华大学学报（自然科学版）》
EI
CAS
CSCD
北大核心
2003年第10期1321-1323,1331,共4页
Journal of Tsinghua University(Science and Technology)
基金
国家自然科学基金资助项目(50274046)
