云南斑岩型多金属金矿的嵌布特征及赋存状态研究

Study on the Inlay Characteristics and Occurrences of Yunnan Porphyry Polymetallic Gold Deposits

云南西部有大量低品位金矿资源,且具有嵌布粒度不均匀、矿石结构复杂、解离不完全等特点,传统工艺矿物学分析不易快速、准确测定金赋存状态及载金矿物的嵌布特征。本文利用矿物自动分析系统(MLA)、化学分析等方法对滇西多金属金矿进行系统的工艺矿物学研究,查明了该矿的矿物组成、嵌布粒度、连生及包裹关系,同时阐明了载金矿物的工艺矿物学性质对金回收率的影响。结果表明:金主要以游离态自然金的形式存在,嵌布粒度极细,主要集中在0.01~0.02 mm粒度级别;小于0.074 mm粒级的金占原矿总金量的50.08%,其余金以微细包裹体分散于黄铁矿、磁铁矿、黄铜矿等载金矿物中。但载金矿物粒度较细,解离性差,嵌布不均匀,因此提高载金矿物解离度是提高金回收率的一个重要参考方向。

BACKGROUND： In the Western Yunnan,there is an abundance of low-grade gold resources with uneven grain size, complicated ore structure and incomplete separation. Using the traditional mineralogical analysis process,it is difficult to achieve accurate and rapid determination of the occurrence of gold and the inlay characteristics of gold-bearing minerals.OBJECTIVES： To study the mineralogy process of polymetallic gold ores in Western Yunnan.METHODS： The mineral composition, dissemination size,and inclusions characteristics of gold ores were analyzed,and the effect of mineralogical properties ofgold-bearing minerals on the recovery of gold was determined. The X-ray Fluorescence Spectrometer and eight-lamp flame graphite furnace integrated Atomic Absorption Spectrometer were used for the analysis of ore properties,and the ore samples were analyzed by Mineral Liberation Analysis.RESULTS： The results show that gold is mainly in the form of free gold,with superfine dissemination size of gold minerals,mainly concentrated on the 0. 01 mm to 0. 02 mm granularity level. Gold smaller than 0. 074 mm presents as free monomer natural gold,which accounts for 50. 08% of the total gold. Other gold occurs as inclusions in pyrite,magnetite and chalcopyrite. However,the gold-bearing minerals have small grain size,poor dissociation,and uneven embedding.CONCLUSIONS： Increasing the dissociation degree of major gold-bearing minerals is an important method for increasing gold recovery.