都龙超大型锡锌多金属矿床“低品位矿化废石资源”特征与分布规律

The features and distribution rules of low grade ore resource in the Dulong supper-large Sn-Zn polymetallic deposit, Maguan, Yunnan Province, China

云南省马关县都龙锡锌多金属超大型矿床是滇东南3大锡石硫化物矿床之一,铜街—曼家寨(铜曼)矿段是矿区最主要矿段,随着生产规模的扩大,矿山地质资源逐步被消耗,寻找可接替资源是当前矿山紧迫任务。本文研究表明,铜曼矿段内"低品位矿化废石资源"分布广泛,储量巨大,具有重要开采价值。通过该矿段地质勘探与生产的总结,发现"低品位矿化废石资源"与锡锌多金属工业矿体空间分布基本一致,下寒武统新寨岩组第2段和第3段碳酸盐岩夹片岩是最有利的赋矿地层,其中工业主矿体周围、大理岩与片岩层间剥离断层带和断层破碎带是该类资源的主要矿化类型。"低品位矿化废石资源"与工业矿石矿物组成和金属矿物嵌布特征基本一致,仅矿石矿物所占比例相对较低,该类资源以夕卡岩型硫化矿石为主,其次为大理岩型和片岩型硫化矿石;矿石中Sn、Zn和Cu等3个矿化元素均呈较好正相关关系,表明这些有价元素在矿石中共生关系密切。此外,矿区平面上成矿元素分带明显,由西至东,Zn逐渐变低,Sn和Cu则呈现明显升高趋势,而由北至南,呈现Sn-Cu-Zn(北部)→Zn(中部)→Sn-Zn(南部)变化趋势。该研究成果为都龙矿山"低品位矿化废石资源"开采和富集回收提供了新的依据。

The Dulong super-large Sn-Zn polymetallic deposit in Maguan County, Yunnan Province is one out of three cassiterite sulfide deposits in the southeastern Yunnan, China. The Tongjie-Manjiazhai ore block is the uppermost one of the deposit. With the expansion of mining and developing scales for years, geological resources of the Dulong mine are gradually consumed, so it is an urgent task for the mine to explore new alternative mineral resources. The researches show that there are widely distributed large amounts of ‘low-grade ore resource’ in the Tongjie-Manjiazhai ore block with important exploiting value. Based on the summary of the geological exploration and production data of the Tongjie-Manjiazhai ore block, it is found that the spatial distribution of "low grade ore resource" is consistent with those of Sn-Zn polymetallic industrial orebodies. Especially, carbonate rocks with schist of the 2nd and 3rd members of the Lower Cambrian Xinzhaiyan Formation are the most favorable host strata for the low grade ore resource, which occurred dominantly around the main industrial orebodies, in fault zone of detachment between marble and schist, and shattered fault zone. The mineral components and metal mineral distribution characteristics of the low-grade ore resource are similar to those of the industrial ore, only its proportion of ore minerals is lower than that of the industrial ore. The low-grade ore resource can be classified as the major skarn type sulfide ore, minor marble type and schist type sulfide ore. Furthermore, the positive relationships of two elements out of Sn, Zn and Cu in the low grade ore resources indicate that there are close paragenetic relationship among valuable elements of Sn, Zn and Cu. In addition, there is obvious zonation of ore-forming elements in the plane of the deposit, as the Zn grades of ores are decreased, but the Cu and Zn grades of ores are increased gradually from west to east, whereas the association of ore-forming elements is changed from Cu+Zn(northern) to Zn(central) to Sn+Zn(southern) from north to south in the plane of the deposit. This research has provided new evidences for the mining, mineral separation and recycling of the low grade ore resources of the Dulong mine.