Tracking of critical minerals/elements using multispectral quantitative analysis: the case of Chelopech (Bulgaria)

The Chelopech gold-copper mine is localized in the western part of Bulgaria and is one of the largest gold producer in Europe. The most of extracted copper in Chelopech Mining come from arseniate sulfosalts (enargite and tennantite) but also sulphides such as bornite, chalcopyrite and covellite. Gold, silver and critical elements (Ge, Te and Se) are associated with this mineralization but only gold and silver are recovered. An image processing method is applied on different flotation plant samples: ore after milling, tailings 1; tailings 2, total tailings and concentrate. Polished sections made with these samples are analyzed in order to quantify the mineral amounts in each sample. The purpose of this quantitative analysis is to know the nature and proportions of mineral phases at each stage of the process. This study allow to know in which forms copper, arsenic and trace elements are present in the different samples and to track them during the different stages, which is very relevant information in order to improve ore treatment and tailings management.