微波活化焙烧辉钼矿生产低硫氧化钼

Preparation of Low-sulphur Molybdenum Oxide by Microwave-activated Pre-calcination of Molybdenite

对比研究了微波功率、作用时间及物料质量对辉钼矿预活化焙烧后的脱硫效果的影响,并采用气-固多相反应的未反应收缩核模型研究了辉钼矿氧化焙烧的动力学。结果表明,辉钼矿的吸波性能良好,在微波功率0.64 k W、物料质量30 g、微波作用6 min的条件下,微波可比常规处理方式显著降低硫含量0.256%;辉钼矿氧化焙烧是强放热反应,温度越高,辉钼矿氧化速率越快;540~630℃时转化率明显增高,界面化学反应是控制性环节。微波对于辉钼矿在常规氧化焙烧之前的活化作用已得到试验验证,若应用于工业生产,可采用短时间活化焙烧预处理来辅助常规的氧化焙烧。

Effect of microwave power,irradiation time and mass quantity on molybdenite activation desulfurization after microwave-activated pre-calcination treatment was studied;unreacted shrinkage nucleus model of gas-solid heterogeneous reaction was adopted to study reaction kinetics.Results show that molybdenite concentrate can absorb microwave well,and optimum desulfurization effect is obtained with 0.64 k W microwave irradiation of 30 g molybdenite for 6 min,and the relative sulphur content was reduced by 65.47%in contrast with traditional oxidizing roasting;the oxidation of molybdenite is a highly exothermic reaction with a faster oxidation rate at higher temperatures;the conversion rate is obviously increased at 540~630°C with interfacial chemical reaction as a rate controlling step.The effect of microwave activation prior to conventional oxidative roasting was tested and verified.As for industrial applications,a short-time activated calcination pretreatment can be used to assist conventional oxidative roasting.