福建某镓锗伴生型铁矿石工艺矿物学研究

通过显微镜观察,采用X射线衍射仪、扫描电镜能谱仪、电子探针及矿物自动检测仪等分析技术,对福建某镓锗伴生型沉积热液铁矿石的矿物组成、镓锗载体矿物嵌布特征、镓锗平衡分配以及赋存状态进行了系统研究,并讨论了镓、锗的替换机制。研究结果表明,矿石中主要有价金属为铁,并伴生有价金属元素镓、锗、钼、银。磁铁矿为最主要的铁矿物,同时也是镓、锗的主要赋存矿物。镓、锗主要是以类质同象置换的形式进入载体矿物的晶格,在矿石中表现出多种赋存形式。矿石中磁铁矿主要嵌布于脉石矿物中,粒度分布极不均匀,主要粒度范围为0.005～0.32 mm,粒级小于0.01 mm的微细粒级分布率高达16.26%,致使磨矿解离较为困难。选矿可采用磁选方法回收主要有用矿物磁铁矿,再通过湿法酸浸、净化、萃取等工艺进行浸出液铁、镓、锗的综合回收。从矿石中回收镓、锗的理论品位为27×10^-6和112×10^-6,理论回收率为40%和82%。

Process Mineralogy Study on an Iron Ore Deposit Associated with Gallium and Germanium in Fujian Province,China

Multiple technics including microscope, X-ray diffraction (XRD), SEM energy dispersive spectrometer, electron probe micro-analyzer (EPMA) and mineral liberation analyser (MLA) were adopted to study the mineral compositions, dissemination characteristics and occurrences of gallium and germanium-bearing minerals in a sedimentary hydrothermal iron ore associated with gallium and germanium in Fujian Province, China. The substitution mechanisms of gallium and germanium are also discussed. The results show that the main valuable metal in the ores is iron, accompanied by the valuable metal elements of gallium, germanium, molybdenum and silver. Magnetite is the predominant iron mineral and the most important gallium and germanium-bearing phase. Gallium and germanium enter the lattice of carrier minerals mainly in the form of isomorphism replacement and show diverse occurrences. Most magnetite in the ores is embedded in gangue minerals, with extremely uneven distribution of grain size. The grain size mostly ranges from 0.005 to 0.32 mm, and the proportion of grain size less than 0.01 mm is as high as 16.26%, resulting the grinding and dissociation difficult. The method of magnetic separation can be used to recover magnetite firstly, followed by hydrometallurgical means of acid leaching, purification and extraction to recover iron, gallium and germanium from magnetite concentrate. The theoretical grades and recovery rates of gallium and germanium of the ore are 27×10-6, 40% and 112×10-6, 82%, respectively.