含钒云母悬浮氧化焙烧-酸浸提钒试验研究

以陕西某V₂O₅品位2.36%的含钒云母为原料,开展了悬浮氧化焙烧-硫酸浸出提钒工艺研究,考察了焙烧温度、焙烧时间、焙烧气量以及氧气浓度对V₂O₅浸出率的影响,采用X射线衍射、热重分析、傅里叶变换红外光谱等检测手段对焙烧前后含钒云母的结构进行了分析。研究表明,适宜的悬浮氧化焙烧工艺为:焙烧温度950 ℃、焙烧时间4 h、O₂浓度35%、总气量600 mL/min,焙烧产物在硫酸用量(质量分数)20%、液固比6∶1、浸出时间3 h、浸出温度90 ℃条件下进行酸浸,V₂O₅浸出率可达73.34%,实现了含钒云母破晶提钒的目标。

Experimental Study on Vanadium Extraction from Vanadium-Bearing Mica by Suspension Oxidizing Roasting and Acid Leaching

The vanadium-bearing mica ore with V₂O₅ grade of 2.36% from Shaanxi Province was taken as the raw material in an experiment on vanadium extraction by adopting suspension oxidizing roasting and acid leaching process. The effects of roasting temperature, roasting time, gas flow and oxygen concentration on the leaching rate of vanadium were investigated, and the structure of vanadium-containing mica ore before and after roasting process were analyzed by using X-ray diffraction, thermogravimetric analysis, Fourier transform infrared spectroscopy and other detection methods. It is found that the suspension oxidizing roasting process should preferably run at the temperature of 950 ℃ for 4 h, with oxygen concentration at 35%, the total gas volume at 600 mL/min. Then, the obtained products are leached at 90 ℃ for 3 h with sulfuric acid at an amount of 20% (mass fraction), liquid-solid mass ratio of 6∶1. As a result, the leaching rate of V₂O₅ can be up to 73.34%, thus achieving the goal of breaking crystalline structure and extracting vanadium from vanadium-containing mica.