Temperature variation of V-bearing stone coal during decarbonization roasting and effect of roasting conditions

V-bearing stone coal is an important vanadium resource with huge reserves in China. For stone coal with high carbon content, the decarbonization process improves the vanadium leaching rate and reduces the acid consumption. Study of decarbonization temperature of stone coal is beneficial for avoiding high-temperature sintering and utilizing its heat, which is meaningful for efficient and energy-saving roasting. In this paper, the optimum roasting conditions of 650 & DEG;C, 50 min, 500 mL/min, and 20% O-2 were determined. Under the optimal decarbonization and leaching indicators, the entire process of stone coal suspension roasting was systematically analyzed and studied. Within the initial 3.9 min, the sample was rapidly heated to 560.1 & DEG;C and continuing to 10.3 min, the sample temperature raised the highest peak of 741.5 & DEG;C with the decomposition of dolomite and kaolinite. Finally, the sample was cooled to 622.5 & DEG;C at the combustion end. This indicated that the decarbonization mainly occurs in the initial 30 min and the maximum temperature of shale is about 120 & DEG;C higher than the final temperature caused by carbon combustion. In addition, intense combustion and local sintering caused by high temperatures and high oxygen content should be seriously avoided.