Udokan Deposit Research Articles

Deposits of the Udokan-Chineysky ore-magmatic system of Eastern Siberia

The aggregate of ore deposits localized in the Udokan-Chineysky ore district is unique and is the result of multi–stage, polygenetic formation. The deposits of copper and other metals formed at various depths occur within a limited area. The oxide and sulfide ore are spatially associated in the sedimentary rocks pertaining to the Paleoproterozoic Udokan Supergroup and the intrusive mafic–ultramafic rocks of the Chineysky Complex. The granite rocks of the Kodar Complex and gabbro rocks of the Chineysky Complex also date back to Paleoproterozoic. The same age has been established for metasomatic Nb–Ta–Zr–REE–Y and U mineralization in the albitized terrigenous rocks of the Udokan Supergroup (Katugin deposit and Chitkanda prospect) and U–Pd prospects hosted in terrigenous rocks. The U–REE mineralization superposed on the titanomagnetite deposits in the Chineysky pluton has not analogues in the world’s practice. The occurrences of uranium mineralization have been noted in form of pitchblende and U–Th rims around chalcopyrite grains at the Unkur copper deposit hosted in sedimentary rocks. The enrichment in U and Pb has been documented in crosscutting quartz veinlets with bornite mineralization at the Udokan deposit.

Current status in the copper ore processing (review)

The article provides the analysis of process flows used for sulfide and oxidized copper ore treatment, reagent schemes, process equipment, indicators of flotation concentration at a number of domestic and foreign concentrating mills and plants. Autogenous and semi-autogenous grinding mills are widely used at the ore preparatory processing at the first stage of grinding to eliminate medium and fine crushing stages. An alternative is the use of high pressure grinding rolls that can reduce electricity consumption as compared to autogenous and semi-autogenous grinding. There is an increase in the use of large-volume and high-performance ore-preparation and flotation equipment for maintaining the quality and quantity of the product. In addition to ball mills, fine and ultrafine regrinding mills of various configurations are widely used at the stage of rougher flotation concentrate regrinding. The analysis of flotation reagents used to improve separation process efficiency was conducted with domestic and foreign approaches to flotation reagent selection shown. It is noted that foreign concentrating mills often use a combination of main and additional collectors. The paper provides the data on flotation reagents used in the copper sulfide and oxidized ore concentration, and their consumption. A combined diagram of flotation-hydrometallurgical processing of mixed copper ore from the Udokan deposit is considered. Conclusions are drawn about current trends in the processing of copper ores including the choice of equipment.

Оптимизация технологии переработки медных руд Удоканского месторождения

The composition of the mineral raw materials of the Udokan copper deposit has been studied. It is established that the copper minerals antlerite and brochantite are represented both in the form of ordinary and crystal hydrate forms, the properties of which are reflected in the flotation process. Studies were carried out on sulfide, mixed and oxidized samples of ores from the Udokan deposit. A unified flotation scheme for processing such ores with the production of sulfide and mixed copper concentrate with subsequent hydro- and pyrometallurgical methods is recommended. The objects of research are sulfide, mixed and oxidized copper ores of the Udokan deposit. The subject of the study is the technology of processing copper ores. Research objectives: – study of the mineral, material, and chemical composition of copper ores of the Udokan deposit; – study of existing technologies for processing copper ores; – conducting laboratory experiments on sulfide, mixed and oxidized ore samples of the Udokan deposit; – recommendation of a unified enrichment scheme for all types of copper ores of the Udokan deposit. Research methods. The work was carried out on the basis of studying the available sources on the occurrence, composition and structure of copper ores of the Udokan deposit, methods of their processing. In the course of laboratory studies, a flotation method of mineral enrichment was used with the use of operations to stabilize the energy state of the dispersed system (with Eh control) and subsequent electrochemical treatment of the pulp. The authors emphasize that the recommended scheme for processing copper ores from the Udokan deposit will optimize the processing technology and increase the efficiency of mining this deposit. Hydro- and pyrometallurgical methods are the most optimal for processing the obtained sulfide and mixed concentrates

Environmental support of metallurgical plant construction project in the Subarctic Mountains (Trans-Baikal Territory)

The article analyzes the results of the environmental assessment of the construction site of the Udokan mining and metallurgical plant (MMP) in the Kalarsky district of the Trans-Baikal Territory. The Udokan deposit is the largest deposit in Russia with copper reserves of 20.1 million tons. The construction area is characterized by extreme natural conditions, natural complexes that are sensitive to anthropogenic impact. The results of the environmental impact assessment of the territory of the planned construction of the Udokan mining and metallurgical plant for the extraction and processing of copper are analyzed. The impact of the construction and the Udokan project on copper mining is assessed as significant. However, taking into account the observance of all technical and operational standards, it can be assessed as acceptable. Specialists of the Institute have developed and implemented a system of environmental monitoring of the impact of construction on the environment. A set of environmental measures to preserve the biodiversity of mountain subarctic ecosystems is proposed.

Application of Equilibrium-Kinetic Modeling for Predicting the Chemical Composition of Subdump Waters of the Udokan Deposit (Russia)

The paper presents certain aspects of applying equilibrium-kinetic modeling to preliminarily assess the formation of the chemical composition of sewage subdump waters during upcoming mining at the Udokan deposit. The mineral dissolution rates, including oxidative dissolution of sulfides, and sorption of strontium, cobalt, zinc, and nickel on calcite are taken into account. It is shown that the chemical composition of water during interaction with dump rocks changes very slowly. However, such heavy metals as nickel, zinc, cobalt, and molybdenum should accumulate in the aqueous solution of the settling pond within 50 years.

Intensification of Sulfuric Acid Leaching of Copper from Sulfide Concentrates Using Ozone and Iron Ions

Studies have been conducted to establish the patterns of sulfuric acid dissolution of metal sulfides in the presence of environmentally friendly oxidizing agents, ozone and iron(III) ions; determine the parameters and modes of intensified extraction of metals into solution; reduce the consumption of oxidizing agents; and develop the least environmentally intense and most cost-effective methods for the extraction of nonferrous metals from sulfide ores, concentrates, and industrial wastes. A copper sulfide concentrate with a grain size of 0.074 mm (90%) and a copper content of 24.5% obtained by the flotation concentration of ore from the Udokan deposit and ozone with a concentration of 80–180 mg/L in a mixture with oxygen are used for the study. The concentrate is fed into a stirred reactor at a rate of 1–5 mL/s. Patterns are studied within the sulfuric acid concentration range 20–100 g/L and a Fe(III) ion concentration of 7.8–29.2 g/L at a solid phase to liquid phase ratio 1.1–1.5 at a temperature of 18–60°C. It has been established that the use of Fe(III) ions and ozone can significantly intensify the recovery of copper from sulfides in sulfuric acid solutions. The extraction of copper from sulfides increases in proportion to the 2.4-fold increase in the concentration of Fe(III) from 7.8 to 29.25 g/L. Ozone effectively oxidizes Fe(II) and regenerates the oxidizing agent, Fe(III) ions. With an increase in the temperature and iron concentration, the consumption of ozone for oxidation increases; namely, 0.22 mol of O3 is consumed per 1 mol of Fe, which is higher than a theoretical value of 0.17. An increase in the rate of the ozone-assisted extraction of copper from sulfides is achieved by increasing the temperature from 20 to 50°C (by 1.4 times), the concentration of ozone from 85 to 180 mg/L (3 times), the feed rate of the ozone–oxygen gas mixture from 1 to 5 mL/s (2.7 times at 20°C and 3.9 times at 50°C), and by the addition of Fe(III) ions by ~1.5 times at 50°C and [Fe(III)] = 10 g/L. The largest oxidizing activity in the sulfuric acid solution is provided by ozone decomposition products at a temperature of 50°C when the solubility of ozone decreases. The ozone utilization coefficient and specific ozone consumption rate for extracted copper decrease with an increase in the feed rate of the ozone–oxygen gas mixture from 1 to 5 mL/s by 1.42 times at 20°C and by 1.16 times at 50°C and increase with an increase in the temperature and concentration of Fe(III) due to the rapid decomposition of ozone and its unproductive use for the oxidation of iron.

Intensification of sulfuric acid leaching of copper from sulfide concentrates with the use of ozone and iron ions

The studies were carried out in order to establish the patterns of sulfuric acid dissolution of metal sulfides with the participation of environmentally friendly oxidizing agents – ozone and iron (III) ions, to determine the parameters and intensification modes of metal extraction into the solution, reduce oxidizing agent consumption. The purpose of the studies was to develop the least environmentally intense, cost-effective methods for extracting non-ferrous metals from sulfide ores, concentrates and industrial waste. For study, we used copper sulfide concentrate of flotation concentration of ore from the Udokan deposit with a grain size of 90 % –0.074 mm with a copper content of 24.5 %, ozone with a concentration of 80–180 mg/l in a gas mixture with oxygen, fed to the reactor at a speed of 1–5 ml/s. Patterns were studied in the range of sulfuric acid concentration of 20–100 g/l, Fe(III) ion concentration of 7.8–29.2 g/l, temperature of 18–60 °C in stirred reactors with the solid-to-liquid ratio of 1.1 ÷ 1.5. It was found that the use of Fe(III) ions and ozone can significantly intensify copper recovery from sulfides to the sulfuric acid solution. Copper extraction from sulfides increases in proportion to the 2.4-fold increase in the concentration of Fe(III) from 7.8 to 29.25 g/l. Ozone effectively oxidizes Fe(II) and regenerates Fe(III) ions. With the rising temperature and iron concentration, ozone consumption for oxidation increases:0.22 mol of O 3 is consumed per 1 mol of Fe that is more than the theoretical value of 0.17. An increase in the rate of copper extraction from sulfides using ozone is achieved by increasing the temperature from 20 to 50 °C (1.4 times), ozone concentration from 85 to 180 mg/l (3 times), feed rate of ozone-oxygen mixture from 1 to 5 ml/s (2.7 times at 20 °C, 3.9 times at 50 °C), by adding Fe(III) ions (~1.5 times at 50 °C [Fe(III)] = 10 g/l). The highest oxidizing activity in a sulfuric acid solution is provided by ozone decomposition products at a temperature of 50 °C when its solubility decreases. Ozone utilization coefficient and specific ozone consumption for extracted copper decrease with an increase in the ozone-oxygen mixture supply rate with oxygen from 1 to 5 ml/s (1.42 times at 20 °C, 1.16 times at 50 °C) and increase with rising temperature and Fe(III) concentration due to the rapid ozone decomposition and unproductive use for iron oxidation.

The Udokan deposit copper ores processing technology development studies

The Udokan deposit copper ores processing technology development studies

Mineralogical and geochemical features of the postglacial oxidation zone of the Udokan deposit

Mineralogical and geochemical features of the postglacial oxidation zone of the Udokan deposit

Geoinformation Modeling of Sulfide Frost Weathering in the Area of Udokan Deposit

The developed geoinformation technology based on the experimental and computer-aided physicochemical modeling enables quantitative calculation and mapping of aftereffects of geochemical processes in sulfide material dumps in terms of Udokan copper deposit. The role of nitrogen as a component of acid rains is emphasized together with its effect on chemical weathering of sulfides. The authors report modeling and testing data on oxidative leaching of Udokan sulfide ore using nitrogen compounds. The classical and geoinformation approaches to calculating leakage flux being of importance for exploration and geoecology studies in permafrost are compared. The obtained results on intensification of sulfide oxidation under conditions of permafrost allow estimating potential environmental impact of the planned mining operations at Udokan deposit and can be used to improve the current cryo-geotechnologies of metal ore mining.

Age and tectonic setting of the Udokan sediment-hosted copper-silver deposit, Transbaikalia, Russia

The Udokan Cu–Ag deposit in Transbaikalian Russia is one of the largest individual examples of the sediment-hosted stratiform type. Mineralization is hosted by the Udokan Complex, a ~12,000-m-thick metasedimentary sequence deposited between ~2.2 and 2.06Ga in a large intra- to peri-cratonic basin constructed over Archean basement of the Siberian craton. The basin was inverted and metamorphosed to dominantly greenschist facies at ~1.9Ga, as a consequence of the collision between the Aldan and Stanovoi domains.Titanite is a common constituent of the greenschist metamorphic assemblages of the Udokan Complex as well as being an integral part of the stratiform disseminated and associated veinlet Cu sulfide mineralization at Udokan. Titanite crystals were separated from a sample collected in the Medny area of the deposit where typical, high-grade, disseminated and veinlet chalcocite-bornite mineralization is well exposed. Titanite crystals from the disseminated and veinlet fractions were separately dated by the ID-TIMS U–Pb method, with the disseminated fraction returning a concordia age of 1895.3±9.7Ma and the veinlet fraction a concordia age of 1896.7±7.8Ma. Combination of both titanite fractions produced a concordia age of 1896.2±6.2Ma.The titanite age effectively dates the associated Cu sulfide mineralization. Since there is no evidence that titanite growth is appreciably younger than either the mineralization in the Medny area or the Udokan deposit as a whole, a ~1.9-Ga age for the stratiform Cu mineralization is considered likely. This age is undistinguishable from that of regional metamorphism during the collisional orogeny that led to final amalgamation of the Siberian craton and its incorporation into Columbia. The age also confirms Udokan as the world's oldest sediment-hosted Cu deposit and that its formation coincided with a continental-scale orogeny rather than with diagenesis and extensional basin development ~150m.y. earlier.

Sulfidization application during the processing of oxidized copper ores of Udokan deposit

Sulfidization application during the processing of oxidized copper ores of Udokan deposit

Methods of Processing Ores from the Udokan Deposit

Methods of Processing Ores from the Udokan Deposit

Participation of hydrothermal fluids in the formation of deposits of the proterozoic Udokan-Chineysky ore system

Numerous Cu deposits of the Udokan-Chineysky ore district (Udokan deposit of cupriferous sandstones, deposits of the Chineysky pluton, etc.), which occur in sedimentary and igneous rocks, are similar in many genetic features. One of these features is the similar parameters of fluid inclusions (hydrothermal fluids) in quartz of the Udokan deposit, rich chalcopyrite ores from the Rudnyi (Rudnyie deposit, and veins of the Pravoingamakitsky deposit studied previously. Fluid inclusions have the same range of high salinity and homogenization temperatures. These studies combined with geological data allow us to consider the formation of contact sulfide ores from the Chineisky pluton and Pravoingamakitsky and Udokan deposits as a common compound fluid-magmatic ore-generating system. The sedimentary rocks primarily enriched in chalcopyrite, pyrite, and pyrrhotite of the entire section of the Udokan complex served as the host media for the hydrothermal fluids and deposits of various scales.

Biohydrometallurgical technology of copper recovery from a complex copper concentrate

Leaching of sulfide-oxidized copper concentrate of the Udokan deposit ore with a copper content of 37.4% was studied. In the course of treatment in a sulfuric acid solution with pH 1.2, a copper leaching rate was 6.9 g/kg h for 22 hours, which allowed extraction of 40.6% of copper. At subsequent chemical leaching at 80°C during 7 hours with a solution of ferric sulfate obtained after biooxidation by an association of micro-organisms, the rate of copper recovery was 52.7 g/kg h. The total copper recovery was 94.5% (over 29 hours). Regeneration of the Fe3+ ions was carried out by an association of moderately thermophilic microorganisms, including bacteria of genus Sulfobacillus and archaea Ferroplasma acidiphilum, at 1.0 g/L h at 40°C in the presence of 3% solids obtained by chemical leaching of copper concentrate. A flowsheet scheme of a complex copper concentrate process with the use of bacterial-chemical leaching is proposed.

Formation of Sedimentary Rock-Hosted Stratiform Copper Deposits through Earth History

Sedimentary rock-hosted stratiform copper deposits form by movement of oxidized, copper-bearing fluids across a reduction front that results in the precipitation of copper sulfides. Large-scale production of such oxidized fluids, as well as the formation of mobile hydrocarbons (oil) has probably been common since the formation of the first red beds in the Paleoproterozoic, and deposits of this type occur in rocks from the Paleoproterozoic to the Tertiary. However, supergiant deposits are currently recognized in only three basins: the Paleoproterozoic Kodaro-Udokan basin of Siberia, the Neoproterozoic Katangan basin of south-central Africa, and the Permian Zechstein basin of northern Europe. The paucity of data regarding the Udokan deposit makes understanding this system difficult in terms of Earth history events. Both the Neoproterozoic and the Permian were times of supercontinent breakup with major landmasses at low latitudes. This global tectonic framework favored the formation of failed rifts that subsequently became significant intracratonic basins with basal, synrift red-bed sequences overlain by marine and/or lacustrine sediments and, in some basins located at low latitudes, by thick evaporitic strata. The intracratonic setting of these basins allowed the development of a hydrologically closed basinal architecture in which highly oxidized and saline, moderate-temperature basinal brines were produced that were capable of supplying reduction-controlled sulfide precipitation over very long time periods (tens to hundreds of millions of years). The length of time available for the mineralizing process may be the key factor necessary to form supergiant deposits. However, examination of the absolute ages for the Kupferschiefer (Zechstein basin) and Katangan deposits allows speculation that other factors may also have been important. Both the Neoproterozoic and Permian were times of major glacial events. Glaciation may also be conducive for the formation of supergiant sediment-hosted stratiform copper deposits. Glacial periods correspond to magnesium- and sulfate-rich oceans that could have been responsible for additional sulfur in basinal brines developed during evaporite formation and would then be available during the long mineralization process.

Inner structure, composition, and genesis of the Chineiskii anorthosite-gabbronorite massif, Northern Transbaikalia

The Chineiskii anorthosite-gabbronorite massif is the most typical layered intrusion in Russia, which is accompanied by large V and Cu deposits. This massif is first considered to be a component of the Proterozoic volcanic-plutonic system of the Kodar-Udokan district, whose largest massifs are Chineiskii and Lukturskii. This system also comprises numerous dikes (including the Main gabbronorite dike at the Udokan deposit, whose thickness reaches 200 m), which are likely the magmatic feeders of ancient volcanism. An intermediate position in the vertical section of the magmatic system is occupied by gabbroids, whose exposures occur in the peripheral part of the Lurbunskii granite massif. The intrusive rocks were proved to be genetically interrelated and show certain similar geochemical features: they bear elevated TiO2 concentrations and have similar trace element patterns and (La/Sm)N and (Gd/Yb)N ratios (1.5–2.3 and 1.87–2.06, respectively). The Chineiskii Massif is thought to have been formed by the successive emplacement of genetically similar basic magmas, which produced four rock groups with fine and coarse layering and cyclicity of variable rank (microrhythms, rhythms, units, and series). The results of cluster analysis indicate that the rocks can be classified into 13 petrochemical types. The phase and chemical characteristics of the parental melts of these compositions were simulated with the use of the COMAGMAT-3.5 computer model, which was also applied to evaluate the composition of the most primitive initial magma of the whole Chineiskii Massif. Our results indicate that the primitive magma was heterogeneous (olivine + plagioclase ± titanomagnetite + melt) at a temperature of approximately 1130°C. The initial melt had a ferrobasaltic composition and was close to saturation with magnetite at ∼NNO ± 0.5

Effect of features of the mineral composition and conditions of formation of oxidized copper ores of the udokan deposit on their beneficiation technology

It is established that features of the composition and properties of copper sulfates essentially predetermine their flotation behavior. An effective technology for their processing, which makes it possible to obtain high beneficiation indicators due to regulation of the energy state the disperse system and subsequent weak electrochemical effects on the flotation pulp, is developed.

Leaching of copper from ore of the udokan deposit by alkaline solutions

Leaching of copper from ore of the udokan deposit by alkaline solutions

Prospects for combined dressing of copper ores of the Udokan deposit

Prospects for combined dressing of copper ores of the Udokan deposit