甘肃天水李子金矿床物质组分及金银赋存状态研究

甘肃天水李子金矿具有斑岩型和韧性剪切带型两种类型的金矿床。本文在详细野外工作的基础上,采用光薄片鉴定、人工重砂分析、化学成分分析、化学物相分析、电子探针波谱分析等技术方法,查明了矿床主要具有蚀变岩型和石英脉型两种金矿石类型,其中韧性剪切带型金矿矿石类型主要为石英脉型,斑岩型金矿矿石类型主要为斑岩型-蚀变岩型;韧性剪切带...

Material Components and Occurrence States of Gold and Silver in the Lizi Gold Deposit, Tianshui,Gansu Province

Abstract:The Lizi gold deposit in the Tianshui area of Gansu Province can be categorized into two types, i. e. , porphyry and ductile shear zone types. On the basis of detailed field work, we employ analytical techniques of thin sections, artificial heavy sand analysis, chemical phase analysis and electronic probe spectrum analysis to determine that there are two principal types of gold ores, namely altered rock and quartz vein types. Ores from the ductile shear zone type gold deposit are mainly quartz vein type, while ores from porphyry type gold deposit are of the porphyry-altered type. Ores from ductile shear zone have banded, veinlet-stockwork structures, and porphyry ores have disseminated spotted and massive structures. The gold-bearing minerals of these two types are dominated by pyrite with chalcopyrite and galena. Gangue minerals are mainly quartz, next sericite and chlorite. Gold ore is present in an independent mineral form as fissure gold and intergranulaar gold with sizes ranging generally from 0. 074 mm to 0. 010 mm. Silver exists in the minerals of the porphyry-altered rock type. Ore textures and structures facilitate the individual mineral separation, and most of the gold minerals are likely disintegrated to native gold after finely grinding. The overall recovery is more than 93. 5% in this deposit. This research result provides reliable data for further understanding of regional mineralization and design of ore dressing.