Dielectric Properties and Microwave Heating of Molybdenite Concentrate at 2.45 GHz Frequency

Dielectric properties were measured using cavity perturbation method.The temperature rising behaviors of molybdenite concentrate were investigated in the field of microwave.This process was conducted to show the microwave absorption properties of molybdenite concentrate and the feasibility of microwave roasting molybdenite concentrate to prepare high purity MoO3.The dielectric constant,dielectric loss,and loss tangent increase from 3.51 to 5.04,0.22 to 0.51 and 0.065 to 0.102 respectively.They are proportional to the apparent density of molybdenite concentrate in the range of 0.9-1.4 g/cm3.The results show that the molybdenite concentrate has good microwave absorption capacity in the conventional density range.The temperature rising curves show that the apparent heating rate of the molybdenite concentrate increases with the increase in microwave power and decreases with the increase in the sample mass and thickness.The temperature of concentrate sample of 100g reaches approximately 800 ℃ after 5 min of microwave treatment at 0.5 kW of power.Our findings show that it is feasible to prepare high-purity MoO3 from molybdenite concentrate by microwave roasting.