Skoe Deposit Research Articles

New Data on the Conditions of Localization and Composition of Cu–Ni Sulfide Ores in the Western Part of the Oktyabr’skoe Deposit, Norilsk District

New Data on the Conditions of Localization and Composition of Cu–Ni Sulfide Ores in the Western Part of the Oktyabr’skoe Deposit, Norilsk District

New Geochemical and Mineralogical Data on Rocks and Ores of the NE Flank of the Oktyabr’skoe Deposit (Norilsk Area) and a View on Their Origin

The Oktyabr’skoe deposit in the Norilsk ore district is the largest platinum-copper-nickel deposit in the world. It contains a huge main orebody (2.4 km3) of massive sulfide ores and some smaller sulfide bodies. Almost all publications on this deposit are devoted to the main orebody. However, to solve the problems of the deposit genesis, it is necessary to take into account the geological structure of the entire area and the composition of all orebodies. For the first time we present data on the inner structure, geochemical and mineralogical characteristics of the intrusive body, and related the disseminated and massive sulfide ores (orebody number C-5) in the northeastern flank of the deposit. The intrusion studied in the core of the borehole RG-2 consists of several horizons including the following rock varieties (from bottom to top): olivine gabbro-dolerites, taxitic gabbro-dolerites, picritic gabbro-dolerites, troctolites, olivine-free gabbro-dolerites, ferrogabbro, and leucogabbro. The intrusion shows a strong differentiated inner structure where high-Mg rocks (up to 25 wt.% MgO troctolites and picritic gabbro-dolerites) in the bottom are associated with low-Mg rocks (6–7 wt.%, gabbro-dolerites, leucogabbro, ferrogabbro) without intermediate differentiated members (8–12 wt.% MgO olivine gabbro-dolerites). Rocks are characterized by low TiO2 content (≤1 wt.%). Taxitic gabbro-dolerites, picritic gabbro-dolerites, and troctolites contain disseminated sulfide chalcopyrite-pyrrhotite mineralization (32 m thick). Cu and Ni concentrations reach up 0.74 and 0.77 wt.%, respectively. Massive ores (27 m) occur in the bottom part of the intrusion. The ores consist of pentlandite, chalcopyrite and pyrrhotite, the latter mineral dominates. Their chemical composition is stable: Cu/Ni ~1, Pd/Pt varies from 5 to 6. The C-5 orebody is similar to the C-3 orebody in terms of mineral and chemical compositions, and differ from the nearby the C-4 orebody which is characterized by a Cu/Ni ratio changing from 5 to 8. On the basis of geochemical and mineralogical data, it is assumed that orebodies C-3 and C-5 are associated with one intrusion, while the orebody number C-4 is related to another intrusive body. Thus, the deposit has a more complex structure and includes several more intrusions than is usually considered.

Biological Activity of Native and Modified Humic Acids

The samples of native and hydrogen peroxide–modified humic acids (HAs) separated from brown coals of the Tisul’skoe deposit in the Kansk-Achinsk Basin were obtained. The HA samples were characterized by instrumental methods: elemental and technical analysis and EPR spectroscopy. The modification of HAs affected the structural-group composition and decreased the concentration of paramagnetic centers (PMCs). The biological activity of native and modified humic acids was evaluated by phytotesting with the use of Iren varietal wheat seeds as an example. The highest biological activity was manifested at an HA concentration of 0.005%. A tendency toward a decrease in the biological activity with a decrease in the concentration of PMCs was revealed.

Prospects for using mineral resources of southern Russia in aquaculture

In aquaculture, the application of natural mineral raw materials with their ion exchange and adsorption properties is on the increase, which contributes to an increase in the economic performance of fish farms. The Southern Federal District in Russia, the leader in fish production, has active deposits of zeolites, bentonites and glauconites classified as high-grade mineral raw resources containing up to 70% of active components, though almost not used in fish farming. Our research focuses on studying the productive and biological effect of mineral raw materials of the Southern Federal District (Russia) as a mineral supplement to fish feeds (the case of the zeolites from the Proval'skoe deposit in Rostov Region). Zeolite in the amount of 3% was introduced into the starter feeds for sterlet. The studies have shown that zeolites from the Proval'skoye deposit applied to feeds contribute to an increase in weight growth (p≤0.05) and survival of sterlet, to a feed conversion decrease and an increase in protein and energy efficiency ratio, positively affect the composition of fatty acids and the stability of lipid peroxidation. The results obtained suggest the use of mineral raw materials from the Southern Federal District as a dietary component.

Scientific and practical fundamentals of cokeless production of siliceous ferroalloys

Application of mineral carbon as carbonaceous reducing agents instead of coke for siliceous ferroalloys smelting is one of perspective ways of high efficient production of them. Results of industrial tests of expensive coke substitution by long-flame and brown coals during smelting of power-intensive ФС75 ferrosilicon presented. Tests were carried out at three ferroalloys plants of Russia and Kazakhstan. The following coals were used: long-flame coals of Shubarkol’skoe deposit (Kazakhstan), brown coals of Kajchasky open-pit mine (Kuzbass) and Majkyubenskoye deposit (Kazakhstan). The coals have Аd ash content at the level of 3–11%, high indices of reaction ability and specific electrical resistance, increased yield of volatile substances (Vdaf = 42–46%) and content of reducing components (CO, H2) up to 180–215 m3 /t (comparing with 11 m3 /t in coke). At the plant “A” the industrial tests resulted in coke substitution by 88–99% with the mixture, kg/charge: 20 – coal Б, 165–190 – coal Д and 35–60 – wood chips. Satisfactory technical and economic indices of ФС75 ferrosilicon production reached. Because of the volatile substances high yield of Д and Б coals (Vdaf = 44–46 %), an increased temperature of emitted gases (up to 240–270 °С) under the hood observed and at the gascleaning system (up to 160–170 °С). At the plant “B” during ФС75 smelting, the long-flame coal was used constantly to substitute the coke by 84%. At the plant “C”, Kazakhstan, a technological possibility of complete (100%) coke substitution by long flame coal determined. To transfer to cokeless production of siliceous ferroalloys with application of low metamorphized coals of Д and Б grades it is necessary to make considerable changes in existing mode of ferroalloys furnaces running to provide high technical and economic indices of the production. Another variant means construction of new furnaces, adapted to increased temperature of emitted gases, forming at the coals pyrolysis with high yield of volatile substances.

Geology of the western flanks of the Oktyabr’skoe deposit, Noril’sk district, Russia: evidence of a closed magmatic system

The Oktyabr’skoe deposit in the Northern Siberian Platform is one of the world’s largest deposits in terms of platinum-group elements and nickel reserves. The genesis of this deposit has been inferred from the inner geological structure of its central portion and remains a matter of long-lasting and heated discussions. The current dominant hypothesis is that the ores were produced in an open magmatic system. This study is devoted to only one aspect of the complicated problem of ore formation, i.e., the geological structure of the Kharaelakh intrusion to which the huge orebodies are related. Recently, new data have been acquired on the structure and composition of the western flanks of the Kharaelakh intrusion, which pinches out in this direction and does not coincide with basalts as has been suggested in many publications. A distinctive feature of this part of the deposit is that it is cut by numerous relatively thin intrusions of contrasting compositions (from picritic gabbro-dolerite to leucogabbro) that are spatially separated in contrast with the central portion of the deposit, where these rocks occur as discrete layers of a single intrusion. These bodies taper off westward and are “blind” apophyses of the intrusion to which various ore types are related. The inner structure of this part of the vertical section of the intrusion is analyzed based on detailed data on the core material recovered by a number of boreholes and on the chemical and mineralogical characteristics of the ores, which differ from those in the main orebodies in that they possess lower Cu and PGE concentrations (up to 3.5 wt% and 9 ppm, respectively) and hence result in the dominance of pyrrhotite and limited amounts (and smaller grain sizes) of platinum-group minerals. Peripheral sills of the Kharaelakh intrusion were formed by portions of initial magma with different melt/cumulus minerals proportions, forming separate bodies of picritic and olivine-bearing gabbro-dolerite. The last rock varieties comprise disseminated ore, in contrast with the central parts of the intrusion, where these ores are located in the picritic and taxitic horizons. No peripheral sills or dikes connected with lava flows have been found inside the studied area. These facts evidence ore formation in a closed magmatic system.

Methods of Fugitive Emission Reduction in Metallurgical Silicon Production at Kazsilicon Metallurgical Combine

KazSilicon Metallurgical Combine is the first enterprise in the Republic of Kazakhstan to produce highpurity metallurgical silicon. The silicon is produced in a 6.7 MW electric furnace from quartz, obtained from the Sarykul’skoe deposit, and charcoal by the method of vertical directional crystallization. As a result of large fugitive emissions of process gases, the operation of the open-type electric furnace creates very difficult conditions for maintenance work. The presence of leaks and a large number of access windows promotes atmospheric air indraft into the working region of the furnace, which causes the electrodes to break down. To solve these problens, we propose using the thermal pressure head of the process gases and extracting these gases through the furnace roof by means of three gas flues, each with capacity ~25000 m3/h. To extract the process gases fl owing from the furnace through the gasket of the electrode opening, we propose using a slotted hood covering the location of the electrode entry into the furnace. A number of recommendations are also made for improving the design of the electric furnace in order to reduce heat losses and fugitive atmospheric-air indraft into the furnace, eliminate the gas release into the atmosphere in the shop and residential zone, and simplify the operation of the electrode and current-cable holders.

Raisaite, CuMg[Te6+O4 (OH)2]· 6H2O, a new mineral from Chukotka, Russia

Raisaite, CuMg[Te 6+ O 4 (OH) 2 ] · 6H 2 O, is a new mineral found at the Sentyabr’skoe deposit, Ilirney ore district, Western Chukotka, North-Eastern Region, Russia. It is associated with gypsum, malachite, azurite, cerussite, anglesite, brochantite, linarite, posnjakite, chlorargyrite, acanthite, gold, brucite, goethite, coronadite, paratellurite, and xocomecatlite in the oxidation zone of quartz veins with calcite, dolomite, ankerite, muscovite, pyrite, chalcopyrite, galena, sphalerite, hessite, petzite, altaite, primary acanthite and gold, etc . Raisaite occurs as prismatic crystals (up to 0.1 × 0.6 mm), as groups or crusts (up to 0.4 × 0.6 mm) and as dense roundish clusters (up to 0.2 mm in diameter) forming botryoidal aggregates (up to 1 mm across). Raisaite is transparent, light blue to bright sky blue, with a vitreous lustre. Its Mohs’ hardness is ca. 2. Cleavage is imperfect, probably on (100), the fracture is uneven. D meas = 2.82(1), D calc = 2.828 g cm −3 . Raisaite is optically biaxial (+), α = 1.626(3), β = 1.642(5), γ = 1.665(3) and 2 V meas = 80(10)°. The IR spectrum is reported. The chemical composition (average of 7 analyses, H 2 O by difference) is: MgO 10.68, CuO 18.09, SO 3 0.44, TeO 3 41.19, H 2 O calc 29.60, total 100.00 wt%. The empirical formula calculated on the basis of 12 O apfu is: Cu 0.96 Mg 1.11 Te 0.99 S 0.02 O 4.20 (OH) 1.80 ·6.00H 2 O. Raisaite is monoclinic, C 2/ c , a = 9.9078(2), b = 10.1325(3), c = 9.8375(2)A, β = 91.839(2)°, V = 987.09(4)A 3 and Z = 4. The strongest reflections of the powder X-ray diffraction pattern [ d ,A( I )( hkl )] are: 7.088(100)(110), 5.815(35)(−111), 5.690(23)(111), 4.949(91)(200, 002), 4.507(50)(021), 3.533(17)(−202, 022), 3.358(17)(−221), 3.310(21)(221) and 2.694(29)(−132). The crystal structure (solved from single-crystal X-ray diffraction data, R = 0.0186) is unique. It is based on heteropolyhedral zig-zag chains built by alternating edge-sharing Te 6+ O 4 (OH) 2 and CuO 4 (H 2 O) 2 octahedra. Mg(H 2 O) 6 octahedra are connected with the chains from two sides via common O vertices. Adjacent chains are bound by H-bonding forming “layers” which are connected with each other by a system of H-bonds. The mineral is named in honour of the Russian mineralogist Raisa A. Vinogradova (born 1935), Moscow State University. Both the new mineral and its name have been approved by the IMA CNMNC (IMA2014-046).

Relationship of antimony with gold mineralization in the ore districts of Eastern Kazakhstan

In Eastern Kazakhstan, Sb mineralization is the most widespread in the Irtysh and Bakyrchik ore districts of the West Kalba gold-bearing belt. It is spatially related to disseminated gold-sulfide ores at some deposits and is structurally and spatially isolated at others. Disseminated gold-sulfide mineralization is localized in Carboniferous carbonaceous-terrigenous carbonate rocks. It is marked off by zones of dynamic metamorphism and foliation and is characterized by the ribbon-like-lenticular morphology of ore deposits. Later Sb (predominantly, quartz-antimonite) mineralization is formed in an extension setting as brecciated/veined ores. In combination with gold-sulfide ores, Sb mineralization is more diverse. For example, microparageneses with berthierite, native Sb, aurostibite, ullmannite, jamesonite, and tetrahedrite coexist with pocket-vein quartz-carbonate-antimonite mineralization in the gold-sulfide ores of the Suzdal’skoe deposit. Also, Sb-containing minerals such as arsenopyrite and pyrite are observed. Two temperature regimes of mineralization are established here: 418-300°C for gold-polysulfide mineralization and 280-200°C for later Sb mineralization. The isotopic composition of antimonite sulfur at the Suzdal’skoe, Zherek, Zhanan, Bakyrchik, and Dal’ny I deposits shows close values within the interval 534S of -3.8 to 2.5%c, suggesting its great-depth origin. No visible gold is found in the antimonite of the quartz-antimonite veins, but atomic-absorption analysis reveals few ppm or more gold. Point X-ray analysis indicates the possible presence of the so-called “invisible” gold. Microstructural observations, temporal relationships of the parageneses, and studies of gas-liquid inclusions at the Suzdal’skoe deposit permit assigning Sb mineralization to the second productive gold-polysulfide stage of the ore deposition. The late antimonite stage of mineralization is separated from the gold-polysulfide stage by 7 Myr long intramineralization tectonic shifts. Gold-polysulfide mineralization (248.3±3.4Ma) was synchronous with Triassic tectonomagmatic activity.

Acid-resistant articles made of granodiorite, felsite, and Buskul’skoe clay

The phase transitions that take place in firing of clay from the Buskul’skoe deposit, granodiorite from the Severskoe deposit, and felsite from the Pokrovskoe deposit and mixed clays with granodiorite and felsite in different ratios were investigated. The change in the content of crystalline phases (cristobalite, mullite, and quartz) in the initial materials and blends during firing was established by quantitative x-ray phase analysis.

Use of “blue clay” from the Maloarkhangel’skoe deposit in the production of ceramic tiles

The mineralogical composition and technological properties of “blue clay” from the Maloarkhangel’skoe deposit are studied. The possibility of using it in the production of ceramic tiles is considered.

Structure and texture of clays from Gzhel’skoe deposit

Microscopic studies of clays from the Gzhel’skoe deposit have identified variations in their structure and texture correlated with the natural tints of those clays. The clay tint characterizes its type, properties, mineral composition, behavior under heating, and other technological parameters.

Rheology of clays from the Troitskoe deposit

The rheological properties of clays from the Troitskoe deposit are investigated. It is established that this clay contains kaolinite characterized by a disordered structure, which leads to increased viscosity and poor liquescence. The introduction of clay from the Malo-Arkhangel’skoe deposit makes it possible to achieve a satisfactory efflux time.

Flow Properties of Majolica Slip with a Thinning Additive Based on Sodium Polyacrylate

The effect of a new thinning agent, namely 40% sodium polyacrylate (SPA), on flow properties of majolica slip and the effect of hardness of water on changes in suspension moisture are considered. The use of 40% SPA makes it possible to reduce its content in slip by nearly half, compared to sodium silicate solution, to improve the slip flow properties, and to insignificantly decrease its moisture. An optimum content of 40% SPA in thinning a polymineral clay slip from the Gzhel'skoe deposit and a majolica mixture is determined.

Low-melting clays from the Gzhel’skoe deposit

The physicochemical and technological properties of Gzhel’skoe deposit clays are studied. These clays can be recommended as the main material for the production of pottery and majolica products, ceramic tiles, roof tiles, art pieces, etc.

Special features of the chemical and mineralogic composition of clays from the Maidan-Vil’skoe deposit

The chemical and mineralogic composition of clay raw material from the Maidan-Vil’skoe deposit are investigated. The relative instability and regularities of the composition variations in samples taken from different sites and different depths of the quarry are established. Based on the results of correlation analysis, the regression equations and graphic dependences for fast estimation of the content of SiO2, Al2O3, and R2O in the composition of Maidan-Vil’skoe clay are constructed.