Vanadium recovery from stone coal through roasting and flotation
(1. College of Resources and Environmental Engineering, Wuhan University of Technology, Wuhan 430070, China;
2. College of Resources and Environmental Engineering,
Wuhan University of Science and Technology, Wuhan 430081, China;
3. Hubei Collaborative Innovation Center for High Efficient Utilization of Vanadium Resources, Wuhan 430070, China)
2. College of Resources and Environmental Engineering,
Wuhan University of Science and Technology, Wuhan 430081, China;
3. Hubei Collaborative Innovation Center for High Efficient Utilization of Vanadium Resources, Wuhan 430070, China)
Abstract: A new process for vanadium recovery from stone coal by roasting-flotation was investigated based on the mineralogy. The process comprised four key steps: decarburization, preferential grinding, desliming and flotation. In the decarburization stage, roasting at 550 °C effectively avoided the negative effect of the carbonaceous materials in raw ore and generation of free CaO from calcite decomposition during roasting. Through preferential grinding, the high acid-consuming minerals were enriched in the middle fractions, while mica was enriched in the fine and coarse fractions. Through flotation, the final concentrate can be obtained with V2O5 grade of 1.07% and recovery of 83.30%. Moreover, the vanadium leaching rate of the final concentrate increased 13.53% compared to that of the feed. The results reveal that the decarburization by roasting at 550 °C is feasible and has little negative impact on mica flotation, and vanadium recovery from stone coal is conducive to reducing handling quantity, acid consumption and production cost.
Key words: vanadium-bearing stone coal; roasting decarburization; mineralogy; preferential grinding; flotation