研究微波功率及物料量对钛精矿微波干燥的含水率、脱水速率、水分比等干燥特性的影响。实验微波功率范围为119~700W,物料量为5~25g。不同的干燥条件下干燥过程均延续2~8min。研究发现微波功率密度对含水率和干燥速率的影响较大,所有干燥过程都有一个明显的特征,即在初始阶段有加速干燥峰。固定物料量为25g和微波功率为385W时,分别对钛精矿的微波干燥动力学进行研究。结果表明:相对于Page半经验模型,干燥过程更符合Henderson-Pabis指数模型。干燥速率常数随着微波功率的增加和物料量的减少而增加。
The microwave drying of ilmenite was investigated.The effects of power levels and sample mass on drying characteristics of moisture content,drying rate,moisture ratio were studied,with microwave power ranging from 119 W to 700 W and sample mass from 5 g to 25 g.The drying processes were completed within 2-8 min at different conditions.The moisture content and drying rates are found to be dramatically affected by microwave power density.For all drying processes the prior microwave absorption of moisture produces an accelerating peak on the drying rate curves in the initial stage.For the sample mass of 25 g and power of 385 W,the drying kinetics were studied.The experimental results fit better to the Henderson-Pabis index model rather than the Page's semi-empirical model;the drying rate constant k is increased with the increase of microwave power and decrease of sample mass.