我国山西、内蒙古部分矿区煤矸石中蕴藏着锂、镓等战略性关键金属,其锂、镓元素富集逐渐成为研究热点。然而煤矸石中锂、镓含量很低,直接浸出需消耗大量化学药剂,高效、经济的富集锂、镓元素仍存在很大挑战。为提高煤矸石中锂、镓富集效率,针对山西朔州地区煤矸石中锂、镓元素赋存状态和预富集方法展开研究。采用逐级化学提取法、矿物物相组成、矿物解离分析、电感耦合等离子体质谱法、扫描电子显微镜和能量色散光谱,研究了煤矸石中锂、镓元素的赋存状态,利用高梯度磁选探究通过抛除黄铁矿对煤矸石中锂、镓元素预富集的可行性。结果表明,煤矸石主要由高岭土、黄铁矿、石英、方解石、白云母等矿物组成,锂、镓元素主要赋存于硅酸盐类矿物中,黄铁矿中含量较少。原矿中锂质量分数146.37μg/g,镓质量分数25.04μg/g。通过磁选方法抛除黄铁矿可对煤矸石中锂、镓元素预富集,1000mT时,预富集效果最佳,磁选尾矿中锂质量分数210.63μg/g,为原矿中锂含量的1.45倍,锂回收率88.00%。镓质量分数31.88μg/g,高于原矿中镓元素,镓回收率80.07%。

Lithium, gallium and other strategic key metals are endowed in the coal gangue in some mining areas of Shanxi and Inner Mongolia, and the enrichment of lithium and gallium elements has gradually become a research hotspot. However, the content of lithiumand gallium in coal gangue is very low, and direct leaching needs to consume a lot of chemicals, so it is still a big challenge to enrich lithium and gallium efficiently and economically. In order to improve the enrichment efficiency of lithium and gallium in the coal gangue, research was carried out on the state of lithium and gallium in the coal gangue in Shuozhou, Shanxi Province, and the pre-enrichment method. Using step-by-step chemical extraction method, mineral phase composition, mineral dissociation analysis, inductively coupled plasma mass spectrometry, scanning electron microscopy and energy dispersive spectroscopy, the Li and Ga elements in the coal gangue werestudied, and the feasibility of the pre-enrichment of Li and Ga in the coal gangue by removing pyrite was investigated by using high-gradient magnetic separation. The results show that the gangue is mainly composed of kaolin, pyrite, quartz, calcite, mica and other minerals,and the elements of lithium and gallium are mainly in silicate minerals, with less pyrite content. The lithium content in the original ore is146.37 μg/ g, and gallium content is 25.04 μg/ g. Lithium and gallium elements can be pre-enriched in the gangue through pyrite threwoff by magnetic separation. In 1 000 mT, pre-enrichment effect is the best, and the lithium in the magnetically selected tailings is210.63 μg/ g which is 1.45 times of lithium content, the lithium recovery rate is 88.00%. Gallium recovery rate is 31.88 μg/ g which ishigher than the gallium element in the original ore, and gallium recovery rate is 80.07%.

0 引言

1 试验

   1.1 试验样品

   1.2 样品表征

   1.3 逐级化学提取程序

   1.4 高梯度磁选试验

   1.5 样品表面元素分布测试

2 结果与讨论

   2.1 样品表征

   2.2 逐级化学提取分析

   2.3 高梯度磁选结果

   2.4 磁选前后样品表面元素分布

3 结论