Experimental study on microbial desulphurization of sulfide ores and self-heating simulation of ore heaps under ultrasonic and microwave

The objective of this study was to improve the efficiency of microbial desulphurization of sulfide ore by pretreatment with ultrasonic and microwave techniques. Different combinations of ultrasound and microwave were used to pretreat the sulfide ore and compare the microbial desulphurization effect of the treated ore and the raw ore. The experimental results show that ultrasonic and microwave can effectively improve the efficiency of bacterial desulphurization, whereas the pretreatment method of ultrasonic followed by microwave has the best enhancement effect on bacterial desulphurization of sulfide ores. The best experimental combination for microbial desulphurization is ultrasonic power of 300 W, ultrasonic action time of 50 mins and microwave power of 500 W, microwave action time of 20 s. In subsequent self-heating simulations of sulfide ore heaps, the optimal ultrasonic and microwave combination was used to pretreat the ores and the two-dimensional temperature field of the heaps was reconstructed. The results further show that the microbial desulphurization efficiency is increased when the sulfide ore is pretreated with ultrasonic followed by microwave. The purpose of inhibiting the self-heating reaction and preventing spontaneous combustion of sulfide ore was achieved.