内蒙古某钨铋银多金属矿矿物学特征及赋存状态研究

Study on the Mineralogical Characteristics and Occurrence States of a Tungsten-Bismuth-Silver Polymetallic Ore in Inner Mongolia

摘要:

为高效开发利用内蒙古某钨、铋、银多金属矿，通过矿物自动定量测试系统（MLA）、X射线衍射仪（XRD）、光学显微镜观察，以及采用单矿物分选等综合技术手段，系统分析了该矿矿石的矿物组成、元素赋存状态及矿物的嵌布特征。结果表明，该矿矿物组成复杂，金属矿物种类繁多，并且共生关系密切。该矿矿石中有价元素主要包括钨、银、铋、铜和锌。钨主要以黑钨矿形式存在，其嵌布粒度较粗，主要赋存于石英脉中，并与黄铁矿共生；铜矿物以次生硫化铜为主，并伴有因硫酸铜溶液交代作用而形成的铜蓝，其与黄铁矿、闪锌矿等矿物紧密共生，且嵌布粒度微细，严重影响铜矿物与其他硫化矿物的浮选分离；铋矿物以硫化铋和氧化铋为主，其嵌布粒度较细且表面易氧化，导致浮选时可浮性差异明显，影响回收效率；银的赋存状态复杂，大部分银分布于铜、铅、铋矿物中，少量独立银矿物与铅矿物共生；锌以闪锌矿和铁菱锌矿为主，但部分闪锌矿表面因次生蚀变生成蓝辉铜矿环边，增加了铜锌分离的难度。通过研究该矿石性质对选矿工艺的影响，发现多金属复杂连生结构及矿物可浮性相近是制约分选效率的核心因素。次生蚀变作用加剧了铜、铋矿物的多样性，需要针对性调整浮选药剂制度；铜蓝的微细分散的特性及银的复杂赋存状态，对回收率提出了更高要求。基于赋存状态分析发现，黑钨矿可通过重选或磁选高效回收，而铜、铋、银矿物需通过优先浮选或联合流程分选回收，锌的回收则需优化浮选条件以减少铜矿物干扰。通过阐明该多金属矿的工艺矿物学特征，为制定高效选矿工艺流程及提高资源综合利用率提供了关键数据支撑。

Abstract:

In this study， comprehensive techniques， including the Mineral Liberation Analyzer （MLA）， X-ray Diffractometer （XRD）， optical microscopy， and single mineral separation， to systematically analyze the mineral composition， element occurrence states， and mineral dissemination characteristics of the ore. The goal is to provide a scientific foundation for the efficient development and utilization of this ore. The results show that the main valuable elements in the ore include tungsten， silver， bismuth， copper， and zinc. However， the mineral composition is complex， with a diverse range of metallic minerals and intricate symbiotic relationships， which pose significant challenges for beneficiation and separation. Tungsten is primarily present as wolframite， with relatively coarse dissemination and is mainly hosted in quartz veins， showing a notable symbiosis with pyrite. Copper minerals are predominantly secondary copper sulfides， with covellite formed by the replacement of copper sulfate solutions. Covellite is closely associated with pyrite and sphalerite， and its fine dissemination significantly hinders the flotation separation of copper from other sulfide minerals. Bismuth minerals， mainly bismuth sulfides and oxides， have fine dissemination and are prone to oxidation， leading to significant floatability differences and affecting recovery efficiency. Silver exhibits a complex occurrence state， with most silver distributed within copper， lead， and bismuth minerals， along with a small number of independent silver minerals symbiotically associated with lead. Zinc primarily present as sphalerite and smithsonite/ ferro-smithsonite. Secondary alteration has resulted in some sphalerite having a chalcocite rim， which complicates copper-zinc separation. This study highlights how ore properties impact the beneficiation process. The complex intergrowth structure of multiple metals and the similar floatability of minerals are key factors limiting separation efficiency. Secondary alteration has increased the diversity of copper and bismuth minerals， requiring adjustments to flotation reagent systems. The fine and dispersed dissemination of covellite and the complex occurrence state of silver present higher challenges for recovery rates. Based on the occurrence state analysis， wolframite can efficiently recovered by gravity or magnetic separation， while copper， bismuth， and silver require preferential flotation or combined processes. Zinc recovery necessitates optimizing flotation conditions to minimize copper interference. This study not only clarifies the process mineralogical characteristics of the polymetallic ore but also provides essential data to guide the development of efficient beneficiation processes and improve resource utilization.