Improving vanadium extraction from stone coal via combination of blank roasting and bioleaching by ARTP-mutated Bacillus mucilaginosus

In order to improve leaching efficiency of vanadium from stone coal, the combination of blank roasting and bioleaching using Bacillus mucilaginosus (B. mucilaginosus) mutants was evaluated. The atmospheric and room temperature plasma (ARTP) technique was used to generate B. mucilaginosus mutants. The results showed that a mutant B. mucilaginosus BM-50, after ARTP irradiation for 50 s, had the highest acid production. The total content of the organic acid produced by B. mucilaginosus BM-50 was nearly doubled compared with the wild strain after 2 days. After 20 days, vanadium leaching rate with B. mucilaginosus BM-50 reached 18.2%, which was improved compared with the original bacteria (15.3%). A pretreatment via blank roasting for stone coal further improved the vanadium dissolution by bioleaching, namely, 68.3% vanadium was extracted, which was much higher than that without blank roasting. It is shown that bioleaching by bacterial mutants by ARTP irradiation combined with blank roasting has great potential for improving vanadium recovery from low-grade vanadium bearing stone coal.