Известия Томского политехнического университета: Инжиниринг георесурсов (Jan 2023)
GOLD IN ORES OF THE VERNINSKOE DEPOSIT (IRKUTSK REGION)
Abstract
The relevance of the research is caused by poor knowledge of the material composition of the ores of the Verninskoe deposit. The data obtained are an important tool not only for clarifying the predictive and prospecting criteria for gold ore deposits of carbonaceous black shale strata, but also will help increase gold extraction from ore by adjusting the enrichment process scheme. The main aim of the research is to study the mineral form of gold in ores. The object of the research is the ores of the Northern zone of the Verninskoe deposit. Research methods included standard petrographic and mineragraphic analyzes, as well as scanning electron microscopy. Results. Conducted researches have established that mineralization is represented by two morphological types: disseminated and vein-disseminated. A significant part of ore mineralization is confined to the second type. It was revealed that gold is presented in the form of native gold and has a high fineness, most of it (75...80 %) is confined to the vein-disseminated type. Native gold is diagnosed mainly in association with arsenopyrite and pyrite. The variety of forms of segregations is one of the specific features of native gold at this deposit, while gold of irregular shape predominates in the ores. For the variation of the diagnosed forms, a common characteristic feature is noted – subordination to cavities that existed earlier, at the beginning or during the crystallization of gold itself. At the same time, the genesis of these cavities and their outlines and location in the ores are quite different. One of the most common morphological varieties in ores is a wire-like form, observed in cataclasis cracks in arsenopyrite; to a lesser extent, amoeba-like and tear-shaped forms are diagnosed, forming numerous tiny inclusions of gold in ores.
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