Temperature-rising characteristic of chromite ore fines containing coal in a microwave field

The microwave heating technique can avoid the non-homogeneous phenomenon of transferring heat and mass in pulverous ore materials by conventional heating. The temperature-rising characteristic of chromite ore fines containing coal in a microwave field was experimentally investigated with a microwave metallurgy oven. The results showed that chromite ore fines containing coal had a better temperature-rising characteristic in the microwave field of 2.45 GHz in frequency. Under the condition of the microwave power of 10 kW and the ore fines' mass of 1 kg, chromite ore fines containing coal reached 1 100℃ in 7 min with a temperature-rising rate of 157.1℃·min^-1 whereas magnetite ore fines containing coal reached 1000℃ in 10 min with a tempera-ture-rising rate of only 100℃·min^-1. Increasing the carbon-oxygen mole ratio can enhance the heating effect of chromite ore fines containing coal and reduce the effect of lime addition on the temperature-rising rate.