安徽庐江沙溪铜金矿床蚀变岩地球化学特征和金的赋存状态研究

Occurrence state of gold in sulfide in Shaxi copper-gold deposit,Lujiang,Anhui Province

斑岩型铜金矿床是金资源的重要来源,研究其中载金矿物(如硫化物)的种类其中的金含量是高效回收金的关键。本文通过对沙溪矿床不同类型蚀变岩和工业品位矿石开展系统的矿物学和地球化学成分研究发现,沙溪矿床中钾化蚀变更富集Si、Fe和K、贫Na,青磐岩化蚀变更富集Al和Fe、贫Ca,石英绢云母化更富集Ca和Na、贫Fe和K。矿石内主要脉石矿物为石英含量为37.65 wt%,钠长石含量为17.15 wt%,碱性长石含量为11.35wt%,白云母含量为12.87 wt%,硫化物黄铁矿和黄铜矿含量分别为1.36 wt%、1.17 wt%。金是以类质同象替换的形式存在于黄铁矿和黄铜矿中,在二者中的占比分别为5.98%、2.15%,其他类型占比为91.87%。

Porphyry deposit is an important source of gold.The key to efficient recovery of gold is to study the types of gold-bearing minerals(such as sulfide)and the gold content in them.Basing on the systematic study on the mineralogy and geochemical composition of altered rocks and industrial-grade ores from the Shaxi deposit,we find that the potassic alteration rocks are more enriched in Si,Fe,K and Na,the prophylitic alteration rocks are more enriched in Al,Fe and Ca,and the phyllic alteration rocks are more enriched in Ca,Na,Fe and K.The main gangue minerals in the ores consist of 37.65 wt%quartz,17.15 wt%albite,11.35wt%alkaline feldspar and 12.87 wt%muscovite.Gold exists in pyrite and chalcopyrite in the form of isomorphic substitution,accounting for 5.98%and 2.15%respectively,and other types account for 91.87%.