Improving vanadium extraction from refractory stone coal by suspension roasting
Shuai Yuan, Yonghong Qin, Yong-peng JIN, Yan-jun LI
Abstract
An innovative suspension roasting−leaching technology in the atmosphere was proposed to improve the vanadium extraction from refractory stone coal. The leaching rate of vanadium was enhanced from 20% previously to 47.14% by present technology at a roasting temperature of 800 °C, a roasting time of 20 min, and a gas flow rate of 400 mL/min. Throughout the suspension roasting process, the surface of the stone coal gradually became rough and irregular. The specific surface area of the particles increased and the lamellar structure of the silicate minerals was destroyed, contributing to the release of vanadium. Meanwhile, the vanadium in the stone coal was oxidized to V(V) or V(IV). The results indicated that the leaching rate was improved owing to the release and transformation of vanadium in the suspension roasting.