铜陵新桥矿床胶状黄铁矿成因及其纳米矿物学特性

发布时间：2018-04-28 18:48

  本文选题：胶状黄铁矿 + 新桥矿床　； 参考：《合肥工业大学》2017年硕士论文

【摘要】：新桥硫铁矿床是长江中下游成矿带铜陵矿集区内层状、似层状硫化物矿床的典型代表,长期以来对其成矿作用存在较大争议。矿床内发育大量顺层产出的胶状黄铁矿,一方面胶状黄铁矿的成因制约了对铜陵矿集区层状硫化物矿床成矿作用及机制的认识,另一方面胶状黄铁矿晶粒细小,有可能成为一种重要的纳米材料资源。本文利用偏光显微镜、粉晶X射线衍射(XRD)、场发射扫描电镜(SEM)和高分辨透射电镜(TEM)等矿物学研究手段,对新桥矿床内胶状黄铁矿的成因及纳米特性进行研究。系统矿物学研究表明胶状黄铁矿为纳米-亚微米粒径的隐晶质黄铁矿,以自形-半自形立方体晶型为主。矿石中含有少量石英及伊利石,呈典型碎屑颗粒形态。SEM和TEM研究表明胶状黄铁矿矿石中仍保存有少量的微生物残体和残留有机质。这些综合信息反映了新桥胶状黄铁矿非岩浆热液成因,而是生物化学沉积成因。该层胶状黄铁矿由于具有较高的地球化学活性,在燕山期岩浆热液的作用下重结晶显著,并对成矿热液形成层状矿体发挥了重要的控制作用。作为一种纳米矿物,胶状黄铁矿的氧化特征有别于普通粗晶黄铁矿。XRD和SEM分析结果显示在自然条件下胶状黄铁矿的氧化分为两个阶段:第一阶段主要生成Fe(Ⅱ)硫酸盐矿物(主要为四水白铁矾和水绿矾),而第二阶段主要生成Fe(Ⅲ)硫酸盐矿物(主要为板铁矾和粒铁矾)。氧化动力学实验结果显示胶状黄铁矿在水溶液中的氧化符合零级反应模型,氧化速度是粗晶黄铁矿的36.8倍。这些特征显示了胶状黄铁矿具有较好的纳米特性。
[Abstract]:Xinqiao pyrite deposit is a typical representative of layered and stratiform sulfide deposits in Tongling ore concentration area of the middle and lower reaches of the Yangtze River. There are a large number of colloidal pyrite occurring in the ore deposit. On the one hand, the genesis of the colloidal pyrite restricts the understanding of the mineralization and mechanism of the layered sulfide deposit in Tongling ore concentration area, on the other hand, the colloidal pyrite has fine grain size. It is possible to become an important nanomaterial resource. In this paper, the origin and nanometer properties of colloidal pyrite in Xinqiao deposit are studied by means of polarized light microscope, powder X-ray diffraction (XRD), field emission scanning electron microscope (SEM) and high resolution transmission electron microscope (TEM). Systematic mineralogical studies show that the colloidal pyrite is a cryptocrystalline pyrite with nanometer-submicron particle size, mainly in the form of automorphic-semi-automorphic cube. The ores contain a small amount of quartz and Illite, which show typical clastic particle morphology. SEM and TEM studies show that a small amount of microbial residues and residual organic matter are still preserved in the colloidal pyrite ore. These comprehensive information reflect the non-magmatic hydrothermal origin of Xinjiao colloidal pyrite, but the genesis of biochemical deposition. Due to its high geochemical activity, the colloidal pyrite recrystallized significantly under the action of Yanshanian magmatic hydrothermal solution, and played an important role in controlling the formation of stratified orebodies in ore-forming hydrothermal solution. As a nano-mineral, The oxidation characteristics of colloidal pyrite are different from those of crude pyrite and SEM analysis. The results show that the oxidation of colloidal pyrite is divided into two stages under natural conditions: the first stage mainly produces Fe (鈪，

本文编号：1816446