Ore Reserves Research Articles

An Examination of the Effectiveness of Various Performance Appraisal Objectives in the Indian Mining Industry

Mining plays a vital role in Indian industry. In the 1990s it accounted for around 3% of GDP, but now it is around 2%. The Indian state of Goa has a thriving mining industry as it has a billion tonnes of iron ore reserves. It exports around 30 million tonnes of iron ore per year. Mineral-based industries include the steel industry and heavy machinery industry. These industries also use minerals and metals as raw materials. Performance appraisal systems have become an important tool for companies to evaluate and maximize employee performance. The purpose of this study is to examine the effectiveness of performance appraisal systems. Performance appraisal has become increasingly part of a more strategic approach to integrating HR activities with company policies and is now regarded as a general term covering a range of activities through which companies attempt to evaluate their employees and develop their capabilities to improve performance and reward.

THE IMPORTANCE OF EXPANDING RESEARCH ON THE SERPENTINIZATION OF OPHIOLITE ROCKS BY NATURAL “WHITE” HYDROGEN FOR KAZAKHSTAN

In Kazakhstan, options and regions for hydrogen production are being considered, including in Western Kazakhstan, the Mangystau region, using the water of the Caspian Lake. The current advanced hydrogen production technologies, including green hydrogen, are very expensive, requiring billions of dollars of investment and potentially creating difficulties for the local population and nature, ecology, flora and fauna. At the same time, geological studies of alternative hydrogen production options in Kazakhstan are poorly developed. Kazakhstan needs and is currently very important to study serpentinization of ophiolite rocks using natural «white» hydrogen. In many countries, there is practically a «gold rush» now, hydrogeologists are conducting research on the search for natural «white» hydrogen. Hydrogeologists have now discovered numerous sources of natural hydrogen in geological environments from Mali to Switzerland, France, Germany, the USA, Canada, and Australia. More than 50 companies have sprung up to discover and mine it. A natural hydrogen well operates in Mali to provide energy to a local city with a population of about 4,000 people for free and forever. Unlike other geological fuels, which are formed over millions of years, natural hydrogen is generated by mixing water and iron particles, serpentinization of ophiolite rocks, and is renewable on the scale of human time, and not in geological epochs. Alternative options for the production and use of hydrogen are presented in this review, including various types of hydrogen, black, gray, green, blue, turquoise, pink and yellow, depending on the method of its extraction and production. Kazakhstan, with the richest natural ore reserves, including coal and polymetals, where ophiolite rocks may be located, may well have deposits of natural «white» hydrogen, such geological studies in Kazakhstan are poorly developed.

Lead and Barium strata-bound deposits in eocene carbonate ramps of Iran: Implications for the influence of sedimentary environment characteristics on the distribution of Ore reserves

In the case of ore deposits that are formed in marine environments, including kuroko deposits, the effect of paleo-sedimentary environment parameters and microfacies changes is very important, but it is often neglected in economic geological research. These factors determine the dispersion and concentration of ore horizons in an ore deposit area, and recognition them leads us to the localization of high concentration ore horizons.In this regard, lead and barite ore deposit area in the southeastern of Tafresh city (the border of Markazi and Qom provinces, Iran) was investigated. This ore deposit is of the kuroko type and is of the early to middle Eocene epoch (Ypresian-Lutetian ages) and was formed in a relatively deep ancient carbonate ramp. Investigating the concentration of different minerals and ore minerals in the mentioned ore deposit area using by remote sensing techniques indicates that the distribution of minerals and ore minerals is non-uniform with a noteworthy correlation unto the carbonate ramp microfacies in the southeastern of Tafresh. The scrutiny of microfacies characteristics and paleo-sedimentary environment showed that the distance from hydrothermal smokers, the action of different seawaves, sedimentological changes, structural features and initial morphology of microfacies have a remarkable impressiveness in the dispersion of ore reserves and the formation of horizons with a high concentration of ore.

ОРТА КӨМІРТЕКТІ ФЕРРОМАРГАНЕЦ ТЕХНОЛОГИЯСЫН ЗЕРТТЕУ ЖӘНЕ ӘЗІРЛЕУ

This article presents the results of medium-carbon ferromanganese smelting from domestic manganese ores under large-scale laboratory conditions. Data on the production and demand for refined ferromanganese produced during the last successful year are provided. Since 2020, refined ferromanganese production has decreased by approximately 1,2 million tons, which is 18% lower than in 2019. This decline was caused by the outbreak of the coronavirus (COVID-19), which began in China in 2019, and the subsequent worldwide pandemic, as well as geopolitical conflicts (Russia — Ukraine), which started in 2021. Kazakhstan has significant reserves of manganese ores, which are in ferrous-manganese and carbonate states. X-ray phase analysis showed that manganese in the ores is represented by hydroxide, pyrolusite, and iron oxide. Medium-carbon ferromanganese was smelted in an electric furnace with a transformer power of 0.1 MVA. The chemical composition of the resulting alloy is as follows, %: Mn – 80-85; Si – 0,05-0,25; Fe – 1,8-3,0; P – 0,05-0,09; C – 1,5-2,0; MnO – 20-25; SiO₂ – 13,94-14,5; CaO – 23,35-24,85; MgO – 12,5-14,0. Thus, an optimal technological scheme for the production of a wide range of manganese ferroalloys was developed.

Classification of Logging Data Using Machine Learning Algorithms

A log data analysis plays an important role in the uranium mining process. Automating this analysis using machine learning methods improves the results and reduces the influence of the human factor. In particular, the identification of reservoir oxidation zones (ROZs) using machine learning allows a more accurate determination of ore reserves, and correct lithological classification allows the optimization of the mining process. However, training and tuning machine learning models requires labeled datasets, which are hardly available for uranium deposits. In addition, in problems of interpreting logging data using machine learning, data preprocessing is of great importance, in other words, a transformation of the original dataset that allows improving the classification or prediction result. This paper describes a uranium well log (UWL) dataset generated with the employment of floating data windows and designed to solve the problems of identifying ROZ and lithological classification (LC) on sandstone-type uranium deposits. Comparative results of the ways of solving these problems using classical machine learning methods and ensembles of machine learning algorithms are presented. It has been shown that an increase in the size of the floating data window can improve the quality of ROZ classification by 7–9% and LC by 6–12%. As a result, the best-quality indicators for solving these problems were obtained, f1_score_macro = 0.744 (ROZ) and accuracy = 0.694 (LC), using the light gradient boosting machine and extreme gradient boosting, respectively.

Will future copper resources and supply be adequate to meet the net zero emission goal?

The fact that in recent times mineral exploration has been disappointing and that transition to clean energy to achieve net zero emission by 2050 will place extraordinary pressure on copper demand, are beyond dispute. The critical question is to what extent will copper supply be capable of satisfying growing demand in a net zero future. Reality is that global copper resources have been growing significantly and steadily for decades despite increasing mine production. Besides, with dwindling exploration discoveries, this increase is primarily attributable to expansion of the resources of existing deposits through a combination of better progressive delineation and re-assessment of classification of resources in response to economic and technological changes, the so-called Australasian Joint Ore Reserves Committee (JORC) ‘modifying factors’. Analysis of MinEx Consulting's global mineral deposit database indicates that just the resources of deposits discovered since 2010 have been growing at estimated Compound Annual Growth Rates (CAGRs) in the range 7.5% to 15.5%, but greater additional tonnage is associated with deposits discovered before 2010. The result is that tens of millions of tonnes of copper are added to the inventory each year, notwithstanding increasing production and mounting Environmental, Social and Governance (ESG) pressure sterilising some deposits. In essence, copper supply shortages are unlikely to result from depletion of copper resources but rather from possible inadequacy of mining and processing capacity. Geopolitical supply risk is also low compared to some other critical metals (e.g., Co and Ni) on account of the large number and geographical dispersion of copper deposits. Increases in price due to a perception of impending scarcity will ensure that future capacity will, at a minimum, continue to grow along its historical 3% CAGR. In addition, it will create strong incentives for above-trend capacity utilisation and improvement in recycling collection and recovery. This will be followed by acceleration of expansion of capacity at many existing mines, and development of deposits at the advanced feasibility stage, releasing copper to market at lower capital cost and on shorter timeframes than exploring for and developing new mines. Estimates of possible levels of above-trend increments in capacity for the various components of the current copper endowment show that, while shortages may occur, they will not be as serious as currently generally expected. This does not mean that net zero emission may not be delayed beyond 2050, but it is more likely that it may be delayed by a range of other constrains and impediments unrelated to availability of copper, and that such delays may give copper supply breathing time.

Substantiating the reliability conditions for the production process at metallurgical enterprises through the fault-tolerant functioning of the system «extraction of raw materials – technological railroad routes – metallurgical production»

The object of this study is the process of formation of insurance reserves at enterprises in the metallurgical industry. Under conditions of uneven supply of raw materials to metallurgical enterprises due to disruption of the transportation process or other reasons, there is a need to create insurance stocks in order to ensure the continuity of production. At the same time, it is necessary to take into account existing restrictions, such as the limited capacity of railroad sections and the impossibility of organizing parallel movement of trains, etc. The presence of these limitations makes it impossible to use classical methods for solving similar problems, such as linear programming. Therefore, to resolve the task, a simulation model was built, based on the discrete-event principle in the AnyLogic University Researcher environment using Oracle libraries and the Java SE compiler. With the help of the model, the process of rotation of dispatch routes at the railroad yard with multiple suppliers and one consignee was formalized. The optimization criterion was chosen to be the minimum deviations of fluctuations in reserves of iron ore concentrate and coke. Analysis of the simulation results revealed that the optimal size of the fleet of railroad routes on the selected rotation polygon is 30 units; at the same time, their utilization rate will be 65 %. It was also established that fluctuations in raw material stocks have a «natural character», which is confirmed by the normal distribution of the density of stock volumes. Under these conditions, the value of fluctuations in the volumes of the main raw materials will be ±13115 t/day for iron ore concentrate, and ±5298 t/day for coke. Reducing the range of fluctuation of raw materials volumes could make it possible to optimize the costs of creating stocks and streamline the transport work of the enterprise for providing raw materials

Practical experience to theoretical innovation: A model for recovering metal resources from industrial solid waste − A case study of copper smelting slag

Industrial solid waste (ISW), a byproduct of modern industrial production, poses significant challenges to sustainable development due to limitations in economic and technical capabilities. Despite containing valuable metal resources, the lack of a coherent approach to its treatment has hindered progress in addressing this longstanding issue. In response, we introduce an innovative model for metal resource recovery from ISW (ISWMRR), with a specific focus on copper smelting slag (CSS) as a prevalent example. This study underscores the efficacy of mineral phase reconstruction technology in converting CSS from a liability to an asset, thereby ensuring a sustainable stream of high-quality raw materials for green steel production amid declining iron ore reserves. Experimental findings indicated that employing the ISWMRR model enabled the successful production of iron products from CSS, yielding an iron concentrate with a TFe (total iron) fraction of 87.21 wt% and iron recovery of 91.24%. This approach facilitated the cost-effective, environmentally friendly, and efficient recovery of iron resources from CSS. By furnishing a novel theoretical framework, our research seeks to guide scientists and industry stakeholders engaged in ISW management.

Transforming Mining Tailings into Green Steel and Rare Earth Elements

As critical components for energy and defense technologies, the U.S. rare earth element (REE) ore reserves are estimated at ~13 million tons, but domestic production is currently limited to one operational mine residing on high-grade ore deposits in Mountain Pass, CA. While low-grade REE deposits are abundant, high-grade American REE deposits are sparse. Meanwhile, hazardous REE-containing tailings pile up at the economic and environmental cost, and it is estimated that REE value locked within e.g., red mud, is $796 per ton. However, such low-grade deposits or mining tailings are challenging to access because REEs are usually locked within a mineral matrix, typically iron oxide, that renders the ore intractable to mechanical or chemical separation. Here, we propose a process for recovering REEs from low-grade deposits and tailings by electro-metallurgically removing iron oxide, hydro-metallurgically removing aluminum salt, and subsequent separating insoluble rare earth oxides. Our strategy produces not only refinable REEs concentrates but also emissions-free iron metal and supplementary cementitious materials as co-products for decarbonizing steel and cement industries, respectively. By addressing the economic and environmental challenges associated with low-grade REE deposits and mining tailings, our electrochemical approach offers a sustainable pathway for unlocking the potential of domestic rare earth resources.

Boosted electrocatalytic activity and durability of Cu[sbnd]Fe/N[sbnd]C by modulating the interfacial composition and electronic structure for efficient oxygen reduction reaction

Oxygen reduction reaction (ORR) serves as the foundation for various electrochemical energy storage devices. Fe/NC catalysts are expected to replace commercial Pt/C as oxygen electrode catalysts based on the structural tunability at the atomic level, abundant iron ore reserves and excellent activity. Nevertheless, the lack of durability and low active site density impede its advancement. In this work, a durable catalyst, CuFe/NC, for ORR was prepared by modulating the interfacial composition and electronic structure. The introduction of Cu nanoclusters partially eliminates the Fenton effect from Fe and optimizes the electron structure of FeNx, thereby effectively enhancing the long-term durability and activity. The prepared CuFe/NC exhibits a half-wave potential (E1/2) of 0.90 V and superior stability with a decrease in E1/2 of only 20 mV after 10,000 cycles. The assembled alkaline Zinc-Air batteries (ZABs) with CuFe/NC exhibit an open-circuit potential of 1.458 V. At a current density of 5 mA cm−2, the batteries are capable of operation for 600 h with a stable polarization. This CuFe/NC may promote the practical application of novel and renewable electrochemical energy storage devices.

Exploring Low-Grade Iron Ore Beneficiation Techniques: A Comprehensive Review

The beneficiation of low-grade iron ores is a key research and development topic in the mineral processing industry. The gradual exhaustion of high-grade iron ore reserves, and rising consumer iron and steel demand globally necessitate efficient low-quality iron ore beneficiation to meet steelmaking quality requirements. This comprehensive review explores various beneficiation techniques for low-quality iron ore, focusing on conventional methods including comminution, froth flotation and gravity separation. This article discusses the principles, processes, and equipment used in these techniques and highlights recent advancements and research efforts in the field. This review also emphasizes the importance of effective beneficiation processes in enhancing economic viability, sustainable resource management, and environmental conservation. Furthermore, it presents a case study of iron ore deposits in Botswana, highlighting the potential economic growth and sustainable development that can be achieved by maximizing resource utilization through reductive roasting, followed by magnetic separation of iron ore using semi-bituminous coal as a reductant. Overall, this review provides valuable insights into low-grade iron ore beneficiation techniques and their significance in meeting the growing demand for high-quality iron and steel products.

Visible-Near Infrared–Short-Wave Infrared Spectroscopy and Mineral Mapping of Hydrothermal Alteration Zones at the Brejuí W-Mo Skarn Deposit, Seridó Mobile Belt, Borborema Province, Brazil

Abstract The Brejuí W-Mo skarn deposit is the main scheelite deposit of the Seridó tungsten province (Borborema province, NE Brazil). It constitutes the largest Brazilian W ore reserve. The orebodies are hosted in the metasedimentary Jucurutu Formation of the Seridó Group (650–610 Ma), close to the margin of the Neoproterozoic Acari pluton (Brasiliano orogeny). Skarns include prograde and retrograde mineral assemblages. Infrared spectral analysis shows that the skarns mainly reflect retrograde mineral assemblages, formed in three different hydrothermal alteration stages with overprinting. Mineral phases spectrally detected include (1) vesuvianite, actinolite, and phlogopite (alteration stage 1), (2) epidote, prehnite, and illite (alteration stage 2), and (3) laumontite, montmorillonite, chlorite, and gypsum (alteration stage 3; main ore zone). Phlogopite chloritization and actinolite recrystallization were observed in the main W-Mo skarn orebodies. Chloritization is marked by a displacement in the Fe-OH–related absorption wavelength (2,246.5–2,250.5 nm). A spectral index using spectral mixtures of laumontite + montmorillonite + actinolite is proposed here to map mineralized skarn layers (WO3 + Mo ≥ 0.1%) in drill cores. It was used to vector to richer mineralized bodies of the Brejuí deposit successfully and may be applied to similar skarn deposits with the same aim.

Distribution of Manganese Ore Deposit in Sukaagung Village, Tanggamus Regency, Lampung

Abstract Manganese ore deposits are one of the most widely used metal alloys in everyday life. Generally, manganese ore deposits are present as residual deposits along with iron ore at certain pH and Eh conditions. These deposits can come from the chemical weathering of crystalline schist, limestone, and dolomite rocks or earlier manganese deposits. In Lampung, the presence of manganese ore can be found in Sukaagung Village, Tanggamus Regency, but little research has been done to determine the distribution and potential of manganese ore in this area. Therefore, this study aims to determine manganese ore distribution and enrichment process in the study area using field data and petrography. In general, manganese ore deposits in Sukaagung Village are present as veins that fill fractures and nodules. Manganese ore deposits that were present as fracture fillers were found intersecting marble, quartzite, and mica schist of the Complex of Gunungkasih Tak Terpisahkan, tuffaceous siltstone from Menanga Formation, and the lapilli tuff and andesite of the Hulusimpang Formation. These deposits are present in manganese as botryoidal and dendritic forms in rock fractures. Meanwhile, manganese ore deposits in the form of nodules are present in submarine volcanic sedimentary rocks in the Menanga Formation. The presence of manganese ore deposits in the study area is thought to be the result of the leaching of manganese elements from the banded iron formation which is associated with the Permian-Cretaceous magmatism, hydrothermal submarine, and rift basin. The acidic fluid dissolves other elements and leaves manganese ore as an economical mineral. Manganese ore is then carried by subsurface fluids, filling fractures in Paleozoic-Tertiary rocks. Even though the distribution of manganese ore in Sukaagung Village is quite wide, further research is needed to determine the potential and reserves of manganese ore in the study area.

Geostatistical Models and Estimation of Laterite Nickel Ore Reserves, Marombo Block, South Sulawesi

Abstract Geostatistical modeling in this study requires a distribution of drill points that have a fixed dimension so that they can produce a reserve accuracy match that is the same as the variograph. The choice of reserve estimation method is prioritized by determining the geological domains of limonite, saprolite and bedrock through a geostatistical approach, namely ordinary krigging (OK) and inverse distance weight (IDW) with the JORC standard (2012), for the accuracy of the limonite and saprolite zone boundaries. The reserve model has shown a definite model of the limonite and saprolite zones and can be used further. By using simulations on cut-off grade (COG) to calculate resources and classify mineral resources, the estimation results obtained mean nickel levels above 1.40% so that the CoG to be used must be greater than Ni 0.90% for limonite, and Ni 1.10% for saprolite. The results of modeling the geometry of laterite nickel ore obtained that the total tonnage shown in limonite was 0.36 wmt (wet metric ton), inferred 0.10 wmt, and indicated in saprolite was 0.58 wmt, inferred was 0.40 wmt.

Обоснование модели прогнозирования контуров рудного тела и содержания полезных компонентов в запасах на основе искусственных нейронных сетей

The ores of the Talnakh deposit are complex, from them they extract: copper, nickel, cobalt, metals, platinum groups, gold, silver, as well as selenium, tellurium, ruthenium and sulfur. Ores have a complex mineral composition and are characterized by a variety of forms of finding useful components. The main ore minerals of all types of ores are: pyrrhotite, chalcopyrite and its varieties, pentlandite and cubanite. Nickel, copper, platinum, palladium, gold and silver are represented mainly by their own minerals; rhodium, ruthenium, osmium, iridium, selenium, and tellurium are in scattered form. As a result of the fact that the ore deposits of the Skalistaya mine lie at a considerable depth (more than 700 m), its ores are classified as dangerous for mountain impacts. Purpose of the study. The commissioning of disseminated ore mine field sections, taking into account the risk of mining impacts, determines the need for accurate information on the content of useful components in a particular section of the deposit, which in turn will increase the efficiency and safety of mining reserves, as well as increase the economic efficiency of the mine. Research methods and materials. Constant geological control, taking samples, rock samples is not always possible or difficult as a result of the high complexity of both field and office work. In addition, the cost of additional exploration of deposits (field sites, production blocks) is significantly high, and the period for obtaining results can reach up to several months. The model developed by the authors for predicting the contours of the ore body and the content of useful components in reserves based on the use of an artificial neural network will make it possible to accurately predict the shape of the ore body, the conditions for its occurrence, as well as the composition and value of the content of useful components in the contours of the mining unit. Research results. The forecast model is based on an artificial neural network of direct distribution, which allows predicting the desired parameters with an error value not higher than 5–10 %. The model developed by the authors allows us to obtain high accuracy of forecasting the conditions of occurrence, the shape of the ore body and the content of components from the forecast data of each forecast well. The period for obtaining geodata on the condition of occurrence, shape and content of useful components is much shorter than the period for detailed exploration of reserves (several hours versus several months, respectively). Discussion of research results. The obtained forecast data are presented in the form of a table on the content of useful components in the disseminated ore reserves on each meter of each forecast exploration well of the grid of forecast wells of the forecast production block. The ore body contours are determined by the predicted content of useful components in the reserves of disseminated ores of the production block, taking into account the data of the grid of forecast exploration wells. Conclusions. To obtain timely and highly accurate information on reserves for both rich ores and disseminated ores, taking into account the depth of development and the presence of danger from mountain impacts, it is necessary to use the forecast model developed by the authors based on an artificial neural network of direct distribution. The model developed by the authors allows us to obtain high accuracy of forecasting the conditions of occurrence, the shape of the ore body and the content of components from the forecast data of each forecast well.

Numerical modelling of the pit wall stability while optimizing its boundaries to ensure the ore mining completeness

Purpose is to assess changes in the stress-strain state of walls along the whole periphery of a super-deep open pit while optimizing its current and final boundaries for the complete ore excavation. Methods. Finite element 3D analysis of stress-strain state (SSS) of the soil and rock mass relies upon the models varying in their scales. Macrolevel model includes the full pit helping perform initial evaluation of its stability depending upon changes in the general wall slope along the pit periphery. Then, the macromodel is separated into sectoral models with smaller scales oriented radially in such a way to include potentially unstable wall areas. The sectoral models make it possible to show the complex bench line in more detail after the peripheries were optimized in terms of economic factor and simulate layered structure of the rock mass. Elastoplastic model of the medium as well as Mohr-Coulomb strength criterion has been implemented using RS3 (Rocscience) program codes. Findings. An indicator of wall strength (safety factor) distribution along the pit periphery has been identified; potential sliding surfaces within each of the separated open pit sectors have been localized based upon the shear strength reduction (SSR) procedure. Influence by the general wall slope as well as by the indicator of the ore excavation completeness on the stripping ratio has been demonstrated. Originality. For the first time, two-level modelling has shown difference in a safety factor depending upon a model scale and a reflection degree of the soil-rock mass structure. In the context of the actual mining and geological conditions of Kacharsky open pit, changes in the safety factor along the pit periphery have been identified depending on the general slope of the wall. Practical implications. Based upon the pit wall stability along the whole periphery, the possibility has been substantiated to optimize its design boundaries for the excavation of those amenable ore reserves, occurred near them, inclusive of ore, occurring in a bottom, which mining is impossible due to inaccessibility.

Integrating selective flocculation techniques for enhanced efficiency in manufacturing processes: A novel approach through artificial neural network modeling

The use of medium and low-grade iron ore is gradually becoming more important due to the depletion of high-grade iron ore reserves and stringent environmental acts/rules. Slimes from iron ore washing were discarded in tailing dams; however, there is currently consideration for recovering iron values from ultra-fines as well. There are enormous fine dumps that are still unutilised. Hence, this study attempt to delve the optimization of iron ore slimes an indeed requirement for manufacturing and design in industries. Leveraging a flocculation process, coupled with the implementation of an Artificial Neural Network (ANN) predictive model, the Kiriburu processing plant serves as the primary source for iron ore slime samples. Chemical analyses of the collected iron samples reveal a composition featuring 58.24 % iron content, 3.47 % Al2O3, 4.72 % SiO2, and 5.18 % LOI (Loss on Ignition). The investigation explores the performance of the flocculation technique under varying pH levels, different pulp densities, and diverse flocculant dosages. Furthermore, the varying parameters selected are pH from 6 to 11, pulp density from 1 % to 15 %, and flocculant dose from 0.03 to 0.27 mg/g. The study's findings showcase a substantial improvement in the Fe grade of iron ore, escalating from 58.24 % to 66.12 %, with an impressive recovery rate of 82.54 % achieved using a flocculant dosage of 0.09 mg/g at pH 10. Additionally, a performance assessment of the selective flocculation method for iron ore slimes is conducted using an ANN predictive model, with recovery as the pivotal parameter. The input parameters for this model encompass pH, pulp density, and flocculant dosages. Employing a three-layer ANN model with a 3–3–1 architecture and utilizing feed-forward back propagation, the study demonstrates a close alignment between predicted values and experimental data, confirming the model's effectiveness for practical manufacturing applications. Information regarding the potential applications of the model's iron ore slime beneficiation efficacy for the manufacturing sector should be considered. This could entail lower waste, more effectiveness, or cost savings. Emphasise any possible ramifications for sustainability or the environment that would make the study pertinent in a larger perspective.

STUDYING THE THERMOCHEMICAL CHARACTERISTICS OF SINTERING WITH ALKALI CONCENTRATE FROM WASTE COPPER TAILINGS

A long period of deposit development leads to a reduction in the volume of balance reserves of ores, while the volume of accumulation of waste (tailings) from mining and processing production increases. In connection with this, an urgent problem is the processing of waste tailings, which can serve as an additional source of commercial products of non-ferrous metals. The set objectives can be achieved by implementing comprehensive extraction of valuable components, reducing fuel, and energy costs at the stage of low-temperature sintering to produce white soot (grade BS-100). In order to determine the amount of heat of chemical reactions during sintering of rough copper concentrate with sodium hydroxide, thermochemical calculations were carried out. For the research, we used rough copper concentrate with a copper content of 4.40% and silver of 77.03 g/t. An equation has been obtained for calculating the heat of chemical reactions of rough concentrate sintering. According to this equation, the greatest contribution to the heat release is provided by the iron content (60%), three times less and equally (19%) - copper and silicon and about 0.2% is absorbed by aluminum. The thermal effect of sintering will be -920.45 kW·h/t of concentrate. From the heat balance of sintering it follows that with an alkali consumption of up to 200% of the mass of the concentrate. The heat of chemical reactions will be sufficient for the autogeneity of the process. Research has been carried out on sintering the concentrate with alkali in the temperature range of 250-500 °C and obtaining white soot from a productive leaching solution with the extraction of 60% silicon. White soot (mSiO2·nH2O) was isolated by two-stage carbonization of a silicate solution with carbon dioxide in a recirculation system with further washing of the precipitate with a solution of sulfuric acid. For citation: Karimova L.M., Kairalapov Ye.T., Makascheva G.K., Kharchenko Ye.M. Studying the thermochemical characteristics of sintering with alkali concentrate from waste copper tailings. ChemChemTech [Izv. Vyssh. Uchebn. Zaved. Khim. Khim. Tekhnol.]. 2024. V. 67. N 7. P. 72-79. DOI: 10.6060/ivkkt.20246707.7004.

New insights into the origin and depositional setting of the Haerdaban Pb[sbnd]Zn deposit, Chinese western Tianshan: Evidence from geology, chert geochemistry, and detrital zircon U[sbnd]Pb geochronology

The Haerdaban PbZn deposit (with an ore reserve of 10.93 Mt. at 1.0–25.65 % Zn and 0.7–12.29 % Pb) is hosted in weakly metamorphosed clastic‑carbonate rocks from the Proterozoic Haerdaban Group. It represents a significant addition of the sediment-hosted PbZn deposits in the Yili block, Chinese western Tianshan. Currently, there are ongoing debates regarding its genesis, with a particular focus on the crucial metallogenic mechanism (syngenetic sedimentary exhalation or epigenetic reworking) responsible for the primary sulfide mineralization. Mineralization at Haerdaban primarily occurs as banded to stratiform ore layers or lenses conformably sandwiched in their host rocks. Vein and stockwork ores occur locally below the stratiform ore layers. A syn-sedimentary fault trending SN was identified based on abrupt lateral changes in lithofacies and thickness of the stratigraphic units. The ore mineralogy is dominated by sphalerite, galena, quartz, and dolomite, with a small amount of pyrite, barite, and organic matter. Detrital zircon LA-ICP-MS UPb dating of the Haerdaban siltstones obtained a maximum depositional age of about 604 Ma. Their geochemical composition similar to the passive continental margin signatures, with rare earth element (REE) patterns enriched in LREE and negative Eu anomalies (Eu/Eu* = 0.50–1.14). Stratiform beds of chert that host disseminated ores have relatively high contents of hydrothermal components (e.g., Ba, Zn), with apparent positive Eu anomalies (Eu/Eu* = 7.38–49.34) and negligible negative Ce anomalies (Ce/Ce* = 0.85–0.98). They are thus interpreted to be hydrothermal sedimentary rocks (exhalites) deposited in a suboxic-anoxic environment proximal to the hydrothermal vents. Integrated geological and geochemical evidence indicates that the Haerdaban PbZn deposit is a typical vent-proximal sedimentary exhalative (SEDEX) deposit formed in a Neoproterozoic Sinian (Ediacaran) passive continental margin rift basin. Post-depositional metamorphism and deformation in the Paleozoic may have caused partial remobilization of primary ores but did not significantly alter the morphology of the orebodies. Furthermore, establishing a genetic model for the Haerdaban deposit has important implications for the exploration of similar deposits preserved in the equivalent stratigraphy within the Chinese western Tianshan region.

Occurrence and lithogeochemical composition of iron ore in Ngororero District, Rwanda

This research aimed to investigate the occurrence and lithogeochemical composition of iron ore in the Ngororero District of Rwanda, with a specific focus on assessing its suitability as a raw material for iron and steel production. The objective was to determine the elemental composition, mineral species, and morphology of the iron ore samples collected from the study area. Eleven samples were collected and analyzed using Inductively Coupled Plasma-Mass Spectrometry (ICP-MS), X-ray diffractogram (XRD), and Optical Light Microscopy. The study shows that Ngororero iron ore is a medium-grade hematite (Fe2O3) ore with iron content ranging from 58.3 % to 65.8 %. Importantly, it contains minimal impurities (less than 3.7 % SiO2 and less than 0.4 % Al2O3) and low levels of detrimental elements (P less than 0.02 % and S less than 0.19 %). While the sulfur (S) content slightly exceeds standard limits, the phosphorus (P) content falls within the acceptable range for commercial iron ores. These findings, marking the first report of iron ore occurrence in the Ngororero District, have significant implications for the potential exploitation of Ngororero iron ore as a valuable raw material in iron and steel production and its suitability for industrial applications. To confirm its economic potential and assess its viability for iron and steel production in Rwanda, the study recommends that additional thorough exploration activities be conducted in this area using both geology and geophysical investigation as well as exploration drilling for iron ore reserve estimation in the study area.