Acid Extraction Of The Stone Coal Vanadium And Calcined Material Leaching Kinetics

For extraction of vanadium from stone coal via acid leaching, this paper is aimed at studying on the process of the roasting, leaching, extracting and kinetic mechanism in acid leaching process, which can provide a fundamental basis for the industrial leaching and utilization of vanadium residue. The paper includes main conclusions mentioned below.1. Optimization of sintering condition of the stone coal has been confirmed as: 0.18-0.25mm in diameter at 850℃for 2.5 hour under thorough oxidization. Optimization of acid leach conditions can be summarized as follows: liquid solid ratio 3:1, leaching temperature 75℃, leaching time 2 hour, sulfuric acid acidity 30%, stirring speed 300 rpm, the leaching rate could reach 81.4% above.2. According to extraction vanadium experiment from leaching stone coal with N236, optimizations of the technical condition are presented below: the process is carried out at room temperature, by adjusting pH to 4.5, organic phase and aqueous phase ratio is 1:3 by clarifying 5 min and extracting 5 times, the rate is 92.4%. As the experiment is carried out strictly under above conditions, a high yield of V₂O₅ is 69.6 %.3. The leaching process can be tracked by online monitor with vanadium ions as indicator electrode.4. The activation energy of the leaching process is 1.56×10³ and 3.99×10³ J/mol at high temperature and low temperature, respectively, which indicates that the extracting process is controlled by diffusion-step under high temperature while controlled by chemical reaction-step under low temperature.