Activity characteristics and activation mechanism of molybdenum tailings under mechanical, mechano-thermal, mechano-chemical, and mechano-thermal-chemical activation

Abstract

Molybdenum tailings (Ms) are a kind of tailings with high crystallinity, and improving their activity using a single activation method is challenging. Existing studies mainly focus on the activation of Ms by specific activation methods. However, few studies compare Ms activity differences and activation mechanisms under different activation methods. To make up for the shortcomings of this research field and improve the utilization efficiency of Ms, the mechanical, mechano-chemical, mechano-thermal, and mechano-thermal-chemical activation were performed to activate Ms. The physicochemical properties of Ms under different activation methods were systematically analyzed. The results showed that mechanical, thermal, and chemical activation could synergistically enhance the activity of Ms. After mechano-thermal-chemical activation, the activity index of Ms was the highest, which was 34.1 % and 16.8 % higher than that of unactivated and mechanical activation, respectively. Adding CaO can weaken the agglomeration force among Ms particles and improve the grinding efficiency. Compared with mechanical activation, the D₅₀ of mechanical-chemical activated Ms was reduced by 36.2 %, and the specific surface area was increased by 34.1 %. Compared with mechano-thermal activation, mechano-chemical activation helped improve the amorphization of quartz, orthoclase, and pyrite, which increased by 10.7 %, 13.6 %, and 83.2 %, respectively. It also helped destroy the Si-O bond, increasing the active Si content by 13.2 %. Compared with mechano-chemical activation, mechano-thermal activation helped improve the amorphization of phlogopite and hornblende, which increased by 13.8 % and 34.8 %, respectively. It also helped destroy the Al-O bond, and the active Al content increased by 78.0 %.