赣东北银山矿田铜矿石中伴生金赋存状态研究

Study on the Occurrence State of Associated Gold in Copper Ores of Yinshan Ore Field in Northeastern Jiangxi

银山多金属矿田可划分为铜和铅锌2个成矿系列。为深入了解银山矿田铜矿石中伴生金的赋存状态和主要矿石矿物的工艺特性,在实地考察和室内测试的基础上,采用岩矿鉴定和扫描电镜等技术手段,对银山矿田九区—西山区铜矿石工艺矿物学特性进行了研究。结果表明:金矿物赋存状态以包裹金(46.41%)为主,其次为粒间金(44.17%)和裂隙金(9.42%)。金矿物粒度以微粒金(94.61%)为主,辅以少量细粒金和中粒金,尚未发现粗粒金和巨粒金。金矿物中Au元素含量为75.87%~95.68%,Ag元素含量为4.32%~24.13%,Ag和Au元素含量比值为0.05~0.32。银山矿田金矿物以银金矿为主,含有少量自然金,金平均成色达到843.7。通过梳理伴生金的赋存状态,有助于优化矿石选矿流程,从而提高金的回收率,增加矿山经济效益。

It has an excellent metallogenic geological conditions in northeast Jiangxi Province,and large ore fields such as Dexing,Lehua and Yinshan have been discovered successively.Among them,the Yinshan polymetallic ore field can be divided into two metallogenic series of copper and lead-zinc.In order to deeply understand the occurrence state of associated gold in Yinshan copper ore and the process characteristics of main ore minerals,on the basis of field investigation and laboratory experiments,the process characteristics of copper ore minerals represented by Jiuqu-Xishan district from Yinshan ore field were studied by the methods such as rock-mineral identification and scanning electron microscopy.The results show that the intercalation state of gold minerals is dominated by wrapped gold(46.41%),followed by intergranular gold(44.17%)and fissure gold(9.42%).The particle size of gold minerals is dominated by fine-grained gold(94.61%),supplemented by a small amount of fine-grained gold and medium-grained gold.Coarse-grained gold and giant-grained gold have not been found yet.The content of gold(Au)in gold minerals is 75.87%~95.68%,the content of silver(Ag)is 4.32%~24.13%,the content ratio of Ag and Au is 0.05~0.32.The gold minerals are mainly silver-gold,less natural gold,the average fineness of gold is 843.7.The natural gold in copper ore is usually golden yellow,and its fineness range is 936.4~956.8,with an average of 946.6.The silver-gold ore in copper ore is usually brass-colored,and the fineness range is 758.7~839.9,with an average of 809.4.The gold-bearing minerals in the copper ore are mainly chalcopyrite,tennantite,pyrite,and some are associated with gangue minerals.By clarifying the occurrence status of associated gold,it is helpful to optimize the ore beneficiation process,so as to improve the recovery rate of gold and enhance the economic benefits of the mine.