某锡铁矿尾矿脱铍回收工艺研究

Study on the recovery process of de-beryllium from a tin-iron tailing

本研究以某锡铁矿尾矿为试验原料,采用高温焙烧-硫酸浸出工艺脱除尾矿中的有毒金属元素铍,考察了焙烧温度、焙烧助剂、浸出时间、浸出温度、液固比、焙烧时间、硫酸浓度等因素对尾矿中铍浸出率的影响。结果表明:尾矿经950℃高温焙烧2h后,以质量浓度30%硫酸作浸出剂,液固比4∶1,在90℃高温条件下浸出6h,可获得铍浸出率86.56%的试验指标;以氨水作为沉淀剂,调整含铍浸出液的pH值至8~9,可获得沉淀BeO品位0.200%、沉淀率98.72%的优异指标。

This study take the tin-iron tailings as raw material to remove toxic metal beryllium by high-temperature roasting-sulfuric acid leaching process. The effect of these factors including roasting temperature, roasting aids,leaching time, liquid-to-solid ratio, roasting time and sulfuric acid concentration on beryllium leaching behavior was investigated. The results indicated that 86.56% of beryllium leaching rate could be obtained after the tailings was directly roasted at 950 ℃ for 2 hours and subsequently leached at 90 ℃ for 6 hours with a mass concentration of 30% sulfuric acid as leaching agent and liquid-to-solid ratio of 4:1,and the excellent index of BeO grade 0.200% and beryllium precipitate recovery 98.72% could be realized using aqueous ammonia as precipitant and adjusting the pH of leaching solution including beryllium to 8~9.