北衙金矿铁锰氧化物中铜、银赋存状态及其形成过程模拟研究

发布时间：2018-11-16 08:46

【摘要】：铁锰氧化物是重要的矿产资源,主要矿物为褐铁矿、硬锰矿,并伴生Au、Ag、Cu、Pb等有价元素,资源储量巨大。Ag、Cu等伴生元素与铁、锰具有极为相似的地球化学参数,这导致了铁锰氧化物中伴生元素的赋存状态复杂多样。现阶段对于铁锰氧化物中伴生元素的赋存状态研究不足,尤其是对伴生元素分散形式的研究较少。而生产中只能回收以矿物形态赋存的伴生元素,难以有效回收分散形式赋存的伴生元素,导致伴生元素的回收率不高。本文通过化学分析和MLA检测分析了矿物中的组分和含量;通过显微镜观察、MLA、XRD、EPMA结合吸附试验、电渗析试验充分研究了铁锰氧化物中铜、银的赋存状态;通过焙烧试验、吸附试验、电渗析对比试验模拟铁锰氧化物中铜、银赋存状态的形成过程,最终得到以下结论:铁锰氧化物以云南大理北衙金矿的褐铁矿为研究对象,化学分析和MLA检测分析了从原矿中提取的褐铁矿单矿物,褐铁矿纯度很高,含有少量的硬锰矿、铅硬锰矿等矿物,元素含量分析Fe52.42%,Mn3.08%,Cu0.33%,Ag50.16g/t。铜、银赋存状态研究表明少量的铜、银以独立矿物和微细粒包裹体的形式赋存在铁锰氧化矿石中。矿物形式是螺状硫银矿、角银矿、自然银、孔雀石、辉铜矿,嵌布粒度不均匀,在1～30um之间。大部分的铜、银以分散形式赋存于褐铁矿、硬锰矿中,分散形式为离子吸附和类质同象。采用合成的氧化铁、氧化锰胶体进行吸附试验来研究铜、银离子在褐铁矿、硬锰矿表层的吸附形式。吸附试验结果表明在同样条件下氧化锰的吸附能力要强于氧化铁。铜、银在氧化锰表层的吸附包括专性配位吸附和静电吸附,在氧化铁表层只有专性配位吸附。对吸附后的氧化铁、氧化锰胶体进行焙烧重结晶,晶体再进行电渗析试验。结果表明,晶体中铜、银的电渗析速度常数小于胶体中铜、银的电渗析速度常数,部分铜、银从离子吸附形式转变成类质同象。推测褐铁矿、硬锰矿在重结晶过程中部分铜、银由初始的吸附状态转化为类质同象形式进入褐铁矿、硬锰矿晶格。
[Abstract]:Iron manganese oxide is an important mineral resource. The main minerals are limonite, permanganite and associated valuable elements such as Au,Ag,Cu,Pb, which have huge reserves. Ag,Cu and other associated elements have very similar geochemical parameters to iron and manganese. This leads to the complex occurrence of associated elements in iron and manganese oxides. At present, the study on the occurrence of associated elements in ferromanganese oxides is insufficient, especially on the dispersion form of associated elements. However, the associated elements in mineral form can only be recovered in production, but it is difficult to recover the associated elements in dispersed form effectively, which leads to a low recovery rate of associated elements. In this paper, the composition and content of minerals were analyzed by chemical analysis and MLA detection, and the occurrence states of copper and silver in iron and manganese oxides were fully studied by microscope observation, MLA,XRD,EPMA binding adsorption test and electrodialysis test. The formation process of copper and silver in iron and manganese oxide was simulated by roasting test, adsorption test and electrodialysis contrast test. The following conclusions were obtained: the limonite of Beiya gold deposit in Dali, Yunnan Province was taken as the object of study. The single mineral of limonite extracted from raw ore was analyzed by chemical analysis and MLA analysis. Limonite is of high purity and contains a small amount of permanganite, lead permanganite and other minerals. The element content of limonite is analyzed by Fe52.42%,Mn3.08%,Cu0.33%,Ag50.16g/t.. Studies on the occurrence of copper and silver show that a small amount of copper and silver occur in the form of independent minerals and fine inclusions in ferromanganese oxide ores. The mineral forms are snail sulfide silver, hornblende, natural silver, malachite, chalcopyrite, inhomogeneous distribution of grain size between 1~30um. Most of the copper and silver are dispersed in limonite and permanganite in the form of ion adsorption and isomorphism. The adsorption of copper and silver ions on the surface layer of limonite and permanganite was studied by using the synthetic ferric oxide and manganese oxide colloid. The adsorption test results show that the adsorption capacity of manganese oxide is stronger than that of iron oxide under the same conditions. The adsorption of copper and silver on manganese oxide surface includes specific coordination adsorption and electrostatic adsorption, but only specific coordination adsorption on iron oxide surface. The adsorbed iron oxide and manganese oxide colloid were roasted and recrystallized. The results show that the electrodialysis rate constant of copper and silver in crystal is smaller than that in colloid. It is inferred that part of copper and silver in limonite and permanganite in recrystallization process are transformed from initial adsorption state to metamorphic form into limonite and permanganite lattice.
【学位授予单位】：昆明理工大学
【学位级别】：硕士
【学位授予年份】：2015
【分类号】：TD91

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