Using the X-ray phase method, the mineral composition of modern mineral sediments of Lake Salda in Turkey was studied. It has been established that the deposits are represented by hydromagnesite Mg5(CO3)4(OH)2×4H2O, guntite CaMg3(CO3)4 and a mechanical admixture of enstatite Mg2Si2O6. The role of organic components (cyanobacteria and diatoms) in the formation of carbonate mineral sediments is noted.

The findings of pyrite in the Novoafonskaya cave and its environs were studied using X-ray phase and mass spectrometric analyses. Pyrite oxidized from the surface, forming a coating of goethite on the outside. The pyrite of the Sushka village area is associated with marcasite. Sulfur (δ34S ‰) of pyrite is enriched in the light isotope; the isotopic composition varies from -14.21 to -34.86 δ34S ‰, CDT. According to these parameters, pyrite corresponds to the sulfur isotopic composition of ancient sedimentary pyrites from the stage of diagenesis of marine chemogenic sediments. Pyrite from the area of the Novoafonskaya cave cave was enriched in the light sulfur isotope as a result of fractionation during biogenic sulfate reduction at the stage of early sediment diagenesis and subsequently did not undergo epigenetic transformations.

The Murmansk region has a significant amount of sulfide copper-nickel raw materials. Deposits of the Nud massif associated with Monchepluton are promising for processing. The Nud II deposit cut-off grade ore with an initial Ni content of 0.45 % and Cu of 0.39 % has been chosen as the research object. During the research, the ore was mixed with ammonium sulfate, grinded, and the mixture was roasted in a muffle furnace with static air atmosphere. The roasted mixture was leached in heated distilled water with constant stirring. The maximum metals recovery was achieved when crushing to a fraction of –40 µm, the ratio of ore : ammonium sulfate is equal to 1 : 7, roasting temperature 400 °C, roasting duration 300 min. In the mixture roasted at these parameters, reflexes of copper and nickel sulfates were recorded by the x-ray phase analysis (XRD) method. At the stage of water leaching, the maximum recovery was: Ni – 79.1 %, Cu – 75.8 %.

The phase transitions of sulfide minerals—pentlandite and chalcopyrite—are tested in roasting with mixture with ammonium sulfate. The behavior of the mixture during roasting is assessed via the synchronous thermal and X-ray phase analyses, and by scanning electron microscopy. The basic optimal technology parameters for the efficient processing of sulfide-bearing copper–nickel ore are selected to be: the roasting temperature of 400 °C, the ore: ammonium sulfate ratio of 1:10, the particle size of –40  $$\mu$$ m and the roasting time of 240 min. An important condition is joint milling of ore and ammonium sulfate down to the specified size. Given these parameters, the later on water leaching of clinker provided extraction of 94.8% of copper, 91.5% of nickel and 82.3% of cobalt. The research findings are of essential practical interest owing to the high recovery of the target minerals.

The development of the housing and communal complex is focused on ensuring guaranteed access of the Russian population to high-quality drinking water. Due to the deterioration of drinking water quality, the mineral composition of sediments in the heating and hot water supply systems of the towns of Apatity and Kirovsk (the Murmansk region) has been studied. It has been established that sediments in the heating system mainly consist of iron oxides and oxyhydroxides: magnetite, goethite and lepidocrocite. All these mineral phases are products of active oxidation (corrosion) of steel pipes and heating system equipment. No mineral phases of ferrous forms of iron have been found in the sediment, which indicates sharply oxidizing environment in the heating system. The presence of sulfur-containing mineral phases, namely, anhydrous calcium sulfate - anhydrite and elemental sulfur, has been recorded in the heating system of the Apatity combined heat and power plant. Indirectly, the presence of such sulfur-containing phases may indicate the possible presence of microflora (bacteria) in the heat-transfer agent, in the metabolic processes of which sulfur and sulfur-containing compounds are involved.

In the Ldzaava cave near the coast of the Pitsunda Bay of the Black Sea, in the carbonate speleothems in the roof of the Central Hall, hollow «boxes» were found, the body of which is composed of perfect flat rhombohedral crystals of calcite close to each other. The mechanism of education is discussed.

This study documents ferruginous accumulations in hypogene karst cavities in the Eocene limestones of central-eastern Crimean Piedmont, including unusual quartz-goethite tubes in Tavrida Cave, and aims to reveal their origin and significance to the problem of iron source for the adjacent Kerch-Taman iron ore province. We employed speleological, petrographic, mineralogical, and geochemical (including REE analysis) methods. Ferruginous materials dominated by goethite precipitated in open cavities, although metasomatic replacement of the host rock also occurred. Although the formation of conduits/cavities enclosing ferruginous materials clearly predated the main phase of hypogene speleogenesis in Tavrida Cave, both speleogenetic phases were controlled by the same cross-formational flow paths. Geochemical characteristics of the studied materials in all sites are largely similar, pointing to their genetic affinity. REEY patterns in most of the samples are remarkably similar to those found in iron formations worldwide, for which significant hydrothermal contribution is established. We show that these accumulations had been formed from acidic, reduced, hydrothermal fluids rising from a deep source and intruding oxidizing environment of the karstified Eocene aquifer, where goethite had been precipitated at the boundary of the iron reduction/oxidation zone. This mechanism is consistent with the hypogene origin of host karst conduits. These findings have implications to the origin of iron ores in the adjacent Kerch-Taman province, where deposits are closely associated with mud volcanoes operating there since at least the Middle Miocene. Although the marine sedimentary (hydrogenetic) origin of these deposits is universally accepted, the source of iron is a matter of debate. Revealing of the deep fluid source of iron for the ferruginous accumulations in hypogene caves in Piedmont suggests that the deep fluid system associated with mud volcanism in the Kerch-Taman region could have been a significant, if not the major, supplier of iron for ore deposits in the Cimmerian basin.

The article is devoted to the results of the study of the mineral and isotopic composition of speleothems of the of the Kholodnyy Grotto cavein the Bzyb gorge of Abkhazia. The cavity was mapped and various types of secondary mineral deposits were recorded. The following mineral formations (speleothems) have been established in the cave: Mondmilch, corallites, guhrs, carbonate breccias, biogenic phosphates. Attention is drawn to the abundance of allogeneic mineral inclusions in drip calcite associated with the weathering products of igneous rocks (zircon, potassium feldspar, ilmenite, rutile, monazite, apatite). The source of these minerals is presumably the weathering crust of the Middle Jurassic volcanics. The oxygen isotope composition of all studied carbonates reflects the participation of meteoric waters. Moreover, the isotopic composition of carbon is subject to significant variations associated with kinetic fractionation (CO2 degassing). Based on the results of petrographic and isotopic studies, an attempt was made to typify speleothems according to the nature of their feeding and the characteristics of crystallization. Also, the cave revealed phosphate mineralization in the form of dark brown thin-layered crusts of hydroxylapatite, formed in place of old guano deposits.

Subject. The aim of the work is to study the mechanism and sources of water formation, as well as the peculiarities of carbonate mineralization in the aquifer of the Kyndyg thermal water deposit. Materials and methods. The samples of water (8) and deposited carbonates (15), collected at different seasons at three sites, characterized by different temperatures and distances from the source, were investigated. pH, Eh, and electrical conductivity were determined by an electrochemical method. For the determination of HCO3 – , Cl– , SO4 2–, titrimetric, mercurymetric and turbidimetric methods were used. Trace element composition was determined by ICP-MS (NexION 300S); strontium isotopic composition – by MC-ICP-MS (Neptune Plus) using the bracketing technique after Sr chromatographic separation. Results. The chloride-calcium hydrochemical type prevails in the studied waters. A number of trace elements in water exceeds the clarke concentrations for groundwater in the supergene zone of mountain landscapes. 87Sr/86Sr isotope ratios (0.7065–0.7072) in thermal waters suggest that their composition is determined rather by the isotopic characteristics of the rocks through which water drains than by the influence of sea water. Among the newly formed carbonates, aragonite prevails. In contrast to thermal water, the concentrations of most metals in carbonates are below the clarke values; only Sr and Se are increased, which content is significantly increased in water as well. Deposited carbonates are characterized by 87Sr/86Sr values (0.7028–0.7074), which are lower than in the source thermal waters. Conclusions. On the basis of hydrogeological, hydrochemical and geochemical data, it can be assumed that the waters of this aquifer complex are formed mainly due to fresh fractured karst waters of lower Cretaceous limestones with submerged monocline dipping into the zone of slow circulation and mixing with sedimentogenic sodium chloride waters. The geochemical data and the presence of scandium anomaly suggest that the underlying Jurassic volcanogenic rocks also participate in water exchange.

Российская академия наук • Уральское отделение Минералогия техногенеза-2019 ПРИВЕТСТВИЯ К УЧАСТНИКАМ XX СЕМИНАРА «МИНЕРАЛОГИЯ ТЕХНОГЕНЕЗА-2019» Уважаемые коллеги и участники конференции!От имени Академии наук Абхазии и Института экологии АНА приветствую участников и гостей XX научного семинара «Минералогия техногенеза-2019» в городе Сухуме!Мы живём в эпоху глобальных экологических проблем, порождённых деятельностью человека, и эти проблемы усугубляются с каждым годом, при этом тонкое знание процессов, происходящих в изменённой человеком среде, приобретает особое значение.Юбилейный семинар -это собрание замечательных учёных и специалистов, являющихся реальным воплощением междисциплинарных контактов и взаимодействий, и он, без сомнения, послужит не только местом обмена достижениями и открытиями, но и станет местом рождения новых идей и провоцирующих мысли гипотез.Хочу выразить особую признательность Сергею Потапову за выбор места проведения юбилейного семинара -столичный город Сухум, стоящий на берегах Сухумской бухты без малого 2500 лет.Абхазия -небольшая страна на карте мира, но представляющая огромный интерес для изучения процессов карстогенеза.Здесь сосредоточены величайшие карстовые гидросистемы и глубочайшие карстовые полости планеты, здесь же представлены все формы карста, встречающиеся на Земле.Очевидно, что семинар послужит импульсом в дальнейшем изучении пещер Абхазии в самых различных аспектах

The relevance of the work is conditioned by the need for a comprehensive study of the mineralogical and microbiological parameters of the Shulgan-Tash (Kapova) cave, which is an archeological monument of universal importance. The purpose of the work: to describe findings of subaquatic stalactites in the Shulgan-Tash cave and to solve mineralogical and genetic issues. Research methodology: hydrochemical, electron microscopic and microbiological techniques of research were used in the present work. Results. This article describes subaqueous stalactoids for the first time in Russia. In the foreign literature they are called “Pool Fingers”. They are the carbonate forming with the origin, which is not yet definitely installed. They are emerging in the coastal zones of the cave waters. Subaqueous stalactoids were found in the Dal'nee Verkhnee lake on the second floor of the Shulgan-Tash cave 700 meters from the entrance. Subaqueous stalactoids are widespread along the Eastern and Western shores of the lake. They are thin and elongated aggregates of cream-colored up to a length of 30 cm, composed of calcite. They were formed in the lake of calcium bicarbonate type water with total mineralization of 390–510 mg/l, their hydrogen index is close to neutral (pH 6.8–7.3) and minor (not more than 5 mg/l) magnesium, sulfates and chlorides. Stalactitical surfaces are covered with the biofilm of the extracellular polymeric substances (EPS) and microorganisms. In their environment, the crystallization of calcite takes place. The “filaments”, whose taxonomic affiliation is not clear are found inside the units in the flattened strands of biological origin. Calcite is a block crystal subindividuals, which possess the elements of splitting. Their size is about 200–300 μm. The manifestation of skeletal crystal growth happens rather often. Researches prove the participation of microorganisms in the origin of subaqueous stalactoids. Apparently, filamentous bacterial mats play the role of the primers and a “framework", which provides a gravity-oriented growth of the aggregates. Extracellular polymeric substance (EPS) has the ability to form complex compounds with ions of Ca2+. It may indirectly lead to the precipitation of calcite. Conclusions. The microbial mediated genesis, similar to that described in the literature of the North American counterparts, was substantiated for the subaqueous stalactoids (Pool Fingers).

A great amount of mine waste creates serious problems for economy and ecology in mining regions. Keeping of dumps and tailings storages requires huge capital costs and material inputs. Removal of overburden volumes cause ecological disequilibrium, ingress of chemical agents and heavy metals in ground and surface water have an adverse influence on eco-systems and human health. These hazards are particularly high under extreme climatic conditions, when mines create vast desert lands around themselves. Foreign researchers use the terms "acid mine drainage" (AМD) and "acid rock drainage" (ARD) when speaking on mine water oxidation and contamination of the environment with heavy metals. AMD is induced by underground mine drainage, natural sulfide-bearing rock exposures, etc. The processes occurring in the interaction the mine water with fine dust particles, as well as water filtering through the thick sulfide rocks have been studied. It has been shown that the reduction in potential environmental hazard of mine water of JSC "Kola MMC" is achieved through precipitation of heavy metals by iron hydroxide and magnesium hydrosilicate. Preliminary assessment of the feasibility of hydrometallurgical processing of disseminated copper-nickel ores has been made

The article presents the results of investigations of sulfate (gypsum) mineral formation in the southern halls of the Novoafon cave in the conditions of a loose loamy aggregate. These sediments, which are sediments of cave lakes, refer to pseudomiosilites and myosilites – essentially quartz rocks, poor hydrolysates. The southern halls of the cave are characterized by air temperatures from 12.2 to 13.4 °C. The maxima and minima lag behind the surface for 2-3 months. Observations of the relative humidity of air are fragmentary, but there are data on its significant fluctuations, increased as a result of anthropogenic transformation of the air circulation system (the appearance of artificial tunnels). The studied aggregates of gypsum are characterized by a size range from less than 1 mm and up to 3-4 cm and a wide variety of morphological types. Gypsum is represented by skeletal crystals on which parts of facets of simple forms occur: {010}, {121} , {110} and rarely {011}. Rounded, lateral with respect to the planes of perfect cleavage {010} of the gypsum surface, speak of a diffuse growth regime. Such a regime can be explained by the composition of the sediments: the clay layers in their composition during the moistening of the cave accumulated capillary water, which was slowly deposited into the growth substrate during the dry periods. Most researchers indicate that in the processes of secondary redeposition of gypsum in caves (irrespective of its initial source) the main role is played by the processes of alternation of moisture with evaporation. Therefore, this type of secondary gypsum mineralization can be considered as an indicator of the microclimatic regime with high-amplitude fluctuations in the relative humidity of air, which has been preserved for a long time. Its further study using isotope techniques can help in the reconstruction of the natural regime of air humidity in the cave (before the anthropogenic transformation of the microclimatic regime).

Pelletized slag of copper-nickel smelter ("Pechenganikel" combine, "Kola MMC" JSC) has been investigated as a potential technogenic deposit. It has been shown that nonferrous metals can be re-extracted from slag using flotation. The work presents the results of laboratory simulation of heap leaching of non-ferrous metals. Ceramic building materials from slag-based feed have been produced and their main properties have been studied