(1. 武汉科技大学 资源与环境工程学院,武汉 430081;
2. 冶金矿产资源高效利用与造块湖北省重点实验室,武汉 430081)
摘 要: 为了提高细粒级含钒页岩的钒浸出率,研究了四种无机分散剂及其添加量对含钒页岩中钒浸出的影响。采用激光粒度分析、实时在线颗粒录像监测、矿浆黏度测定、Zeta电位和红外图谱等手段进行表征。结果表明:当硫酸浓度为8.0%、液固比为1.5:1 mL/g、浸出温度为95 ℃、浸出时间为4 h时,添加1.0%(质量分数)的三聚磷酸钠(STPP)可使细粒级含钒页岩的钒浸出率由无分散剂时的62.0%提高到72.1%。微细粒含钒页岩的浸出反应速率受界面迁移和内扩散共同控制,分散剂通过改变矿物表面Zeta电位使颗粒间黏滞力减小,从而降低矿浆黏度来强化钒的浸出。加入STPP后,矿浆黏度从564 mPa·s降至294 mPa·s;矿浆黏度降低和分散剂吸附是影响钒浸出率的主要因素,添加适量分散剂有利于细粒级含钒页岩钒的浸出反应。
关键字: 细粒级;含钒页岩;分散剂;强化浸出;矿浆黏度
(1. College of Resources and Environment Engineering, Wuhan University of Science and Technology, Wuhan 430081, China;
2. Hubei Key Laboratory for Efficient Utilization and Agglomeration of Metallurgic Mineral Resources, Wuhan 430081, China)
Abstract:In order to improve the vanadium leaching rate of fine-grained vanadium-bearing shale, the effects of four inorganic dispersants and their additions on the vanadium leaching from vanadium-bearing shale were studied. The samples were characterized by laser particle size analysis, real-time online particle video monitoring (PVM), ore pulp viscosity measurement, Zeta potential and Fourier transformation infrared spectroscopy (FTIR). The results show that, when the sulfuric acid concentration is 8.0% (volume fraction), the liquid-to-solid ratio is 1.5:1 mL/g, the leaching temperature is 95°C and the leaching time is 4 h, adding 1.0% (mass fraction) of sodium tripolyphosphate (STPP) can increase the vanadium leaching rate of fine-grained vanadium-bearing shale from 62.0% that without adding STPP to 72.1%. The leaching reaction rate is controlled by the interface transfer and internal diffusion across the product layer. By changing the Zeta potential of the mineral surface, the dispersant reduces the viscous force between particles and the viscosity of ore pulp to strengthen the vanadium leaching. The viscosity of ore pulp decreases from 564 mPa·s to 294 mPa·s after adding STPP. The decrease of viscosity of ore pulp and dispersant adsorption are the main factors affecting the vanadium leaching rate, and a proper amount of dispersant is beneficial to the leaching reaction of fine-grained vanadium-bearing shale.
Key words: fine-grained; vanadium-bearing shale; dispersant; enhanced leaching; ore pulp viscosity