Blank roasting kinetics of illite type vanadium bearing stone coal

Abstract

Vanadium bearing stone coal is an important vanadium resource in China, and roasting is the foundation for extracting vanadium from stone coa1. In this paper, the blank roasting kinetics of illite type vanadium bearing stone coal is studied using the derived kinetics equations of disc-shaped particles. Stone coal samples were roasted at the set temperature and time, the roasted clinker was leached with sulfuric acid. The roasting effect was judged by the leaching rate of vanadium, and the kinetics and mechanism of the roasting reaction were discussed. The results show that the blank roasting process of stone coal is divided into two stages. The first stage activation energy is 159.50 kJ/mol, which follows the control of chemical reaction kinetics; the second stage activation energy is 256.45 kJ/mol, which belongs to diffusion control. In addition, As the roasting reaction proceeds, it can be noted that chemical reaction control can be quickly transformed into diffusion control. The apparent activation energy of the diffusion control is greater than that of the chemical reaction control, which indicates that diffusion is the controlling factor that affects the conversion efficiency of vanadium during the blank roasting process of stone coal. The results of blank roasting kinetics model of disc-shaped particles established in this study are in good agreement with the experimental analysis results, which also verifies the accuracy of this model.

Keywords

• Stone coal
• Vanadium
• Blank roasting
• Kinetics
• Diffusion control
• Chemical control