The results of studies of wallrock hydrothermal-metasomatic processes at a large polymetallic deposit located in the central part of the Novaya Zemlya Archipelago are considered. The geological position and control factors of mineralization, pre-ore and wallrock metasomatites are shown. The material composition of metasomatites has been studied in detail, and rare minerals, such as zinc-bearing dolomite, kimrites, and barium-bearing mica, among others, have been discovered and described, and specific morphology and composition have been revealed for those. According to the structure and material composition of metasomatites and some minerals, the formation conditions are defined as low-temperature near-surface.
The main objects of the research were the deposits of noble and non-ferrous metals of the Urals, Siberia and Novaya Zemlya. It is shown that the establishment of a pomineral balance of distribution of chemical elements in ores, the study of variability of the material composition and stereometric features of ores in the geological space is extremely important to solve the problems of rational use of ore deposits and the prediction of environmental consequences of their development. When assessing the environmental impact of the deposits involved in the exploration and exploitation, both the regularities of distribution of toxic elements and minerals in the volumes of ore bodies and fields, and landscape-geochemical conditions determining the factors of migration and accumulation of these components after their extraction on the earth surface should be taken into account. For geological-economic and environmental forecasting it is necessary to accumulate materials on the distribution of impurity elements, sometimes not playing a role in assessing the industrial importance of deposits, but leading to the emergence of various man-made geochemical anomalies in areas of exploration and mining operations, as well as the formation of man-made deposits in places of waste storage of concentration plants and metallurgical plants.
The main ore minerals in the Gaisky deposit are pyrite, chalcopyrite, and sphalerite. According to the material composition and textural and structural peculiarities, solid and disseminated pyrite, chalcopyrite and chalcopyrite-phalerite natural types of ores are distinguished. At present the Gaisky concentrator processes copper and copper-zinc ores according to the gravity-flotation collective-selective scheme. Hardness and brittleness of minerals have the greatest influence on the result of ore processing. The nature and eminence of ores is mainly determined by the predominant mineral, pyrite. The hardness of pyrite is much higher than the hardness of chalcopyrite, sphalerite and bornite, so there is an overgrinding and slagging of useful minerals with simultaneous underdepositing of their clusters. The density of minerals, size and shape of their grains have a decisive influence on the results of gravity concentration, and native gold, pyrite and galena are accumulated in the concentrate. However, the flattening of gold during pre-grinding leads to its partial loss with gravity tailings. The flotation properties of minerals are decisively influenced by the surface character of the particles, which can be tentatively estimated by the reflection coefficient. Such connection can be used for qualitative prediction of heterogeneity and technological properties of sulfides. It is established that for all ore minerals from early to late generations the reflection coefficient, microhardness increase and the content of microimpurities and noble elements in particular decreases. The described regularities are reflected in distribution of minerals on products of technological processing, and this finally influences on quality of commodity products.
