Ore Quality Research Articles

Ore extraction efficiency in sublevel caving with front-face ore drawing at great depths

The development of ore deposits at the present stage of underground mining is characterized by the continuous withdrawal of rich ore sites deposits, the lack of their recovery and the involvement of poorer ores in mining, high capital intensity and minimal reproduction of the mineral resource base at existing enterprises. The constantly growing depth of mining operations is accompanied by the deterioration in the geological and geomechanical conditions. To increase recovery rates, some technologies require additional material and labor resources, which calls into question the feasibility of their application. The current situation in the mining industry is due to the mediocrity of the mining systems in use and their inability to ensure mineral extraction at a competitive level. One of the promising trends in extraction of medium-grade and quality ores is the development and wider application of sublevel caving with the front-face ore drawing as the technology with the maximum simplification of preparation and extraction layouts, high intensity of mining, minimum amount of working assets and the adapted automation of production processes. The analysis of the technical literature and practical know-how of well-known large mining companies shows the undeniable and obvious advantages of this development system over the other equivalent mining methods. A scientifically based selection of rational parameters for the system of sublevel caving with front-face ore drawing, especially at great depths, can ensure both safety and also high rates of extraction. In this regard, this publication focuses on the influence of structural elements and parameters of ore drawing on ore loss and dilution in the technology of sublevel caving at great depths.

К ВОПРОСУ ГЕОМЕХАНИЧЕСКОГО ОБОСНОВАНИЯ РАЗРАБОТКИ ГОРЕВСКОГО МЕСТОРОЖДЕНИЯ СВИНЦОВО-ЦИНКОВЫХ РУД

The Gorevskoye lead-zinc ore deposit is unique in terms of metal reserves and ore quality, as well as in terms of geomechanical and hydrogeological development conditions. The deposit is located on the banks of the Angara River, part of the ore bodies goes under the channel. Ore mining is carried out by an open method, in the future it is planned to deepen the quarry to a depth of -435 m and switch to a combined method of mining the deposit. It is noted in this work that increasing the depth of the quarry can change the deformed state of the rock column and cause the development of dangerous deformation processes in it, which in turn can cause the penetration of natural water into mine workings. Some developments of the IPCON RAS on the solution of the issues under consideration are outlined. It is proposed to use a comprehensive, interdisciplinary approach that combines engineering methods of forecasting based on production experience, methods of computer modeling of diverse problems (rock displacement, formation of zones of induced permeability of the massif, filtration, explosive impact) and geomechanical monitoring.

Assessment of trends inthe quality of iron ore with an increase in thedepth of mining deposits of the kachkanar group

Assessment of trends inthe quality of iron ore with an increase in thedepth of mining deposits of the kachkanar group

Possibility of eddy current testing of low-conductive heterogeneous media

The possibility of copper ore quality testing for proportion of minerals containing copper in it by the eddy current method has been studied. Copper ore is presented as a low-conductivity heterogeneous medium consisting of two homogeneous ore constituents (enclosing rock and copper mineral). These constituents have significantly different specific electrical conductivity (SEC). For the analysis, the effective medium approximation is used. In this case a heterogeneous ore can be considered homogeneous with an effective SEC, which depends on the quantitative composition of its constituents. To solve this problem, the surface parametric eddy current probe (ECP) of a local type has been developed. Its design is optimized for operation at high frequencies (units – tens of MHz). ECP winding consists of 10 turns with a diameter of 11 mm, which wound up in one layer on a dielectric frame. The ECP signals in the complex plane from samples of copper ore with different content of copper mineral (chalcopyrite) in the resonant operation mode are studied using eddy current flaw detector of Eddycon C type. The operating frequencies are 5, 7 and 9 MHz. It has been established that with increasing frequency in the specified range, signals amplitude has a pronounced tendency to decrease. It is shown that as the frequency increases from 5 to 7 MHz, the phase sensitivity of the developed ECP to the content of chalcopyrite in the ore also decreases. Thus, the phase angle between signals from ore samples with low and high chalcopyrite content at the frequency of 5 MHz is 110°, and at the frequency of 7 MHz – 87.5°. With a further frequency increase to 9 MHz, the phase sensitivity remains practically unchanged, and the amplitude of the signals continues to decrease. This can be explained by a decrease of the ECP sensitivity to SEC changes with a transition to the over-extreme operating point of the complex plane by operating frequency increase. The fundamental possibility of using the eddy current method for the quantitative testing of chalcopyrite in copper ore has been confirmed. Prospects for further research related to the development of an integral-type ECP, in particular, screen ones, whose signals are determined by the content of chalcopyrite in copper ore samples as a whole, are formulated.

Quality Control Model of Ore Processing Based on Elman Neural Network

In this paper, by establishing Elman neural network and decision tree model, the quality control of ore processing is studied and reasonably predicted.Predict the product quality and the temperature corresponding to the target quality. Elman neural network model is established, training set and output set are input for training, and test set is input into neural network to obtain the relative error of real value and training value; After verification, the relative error between our real value and training value is within 100% ± 5%, and the model is accurate; Finally, the input value is substituted to obtain the forecast data.Establish the mathematical model of product qualification rate. The decision tree model is established by using SPSS, and the decision tree system is constructed by using the four factors of system setting temperature, raw ore parameters, process data and final ore quality. Through inspection, our R 2 is 0.999991, close to 1, and the model fitting is good. Compared with other parameters, it can be found that the model has good sensitivity and high accuracy. Finally, the input data is sent into the model to get the final prediction results.

Influence of iron ore properties on dioxin emissions during iron ore sintering

Iron ores are principal input materials for iron and steel-making industries. Quality of iron ores is one of the critical parameters for formation of environmental pollutants related to the steel-making process. Dioxins are identified as one of the most toxic pollutants emitted during ironmaking, specifically during the sintering process. This study applied four types of iron ores and analyzed their moisture, density, particle size distribution and element concentrations to investigate their effect on the dioxin formation during sintering. Each type of iron ore was processed in a sinter pot grate. During each processing route, exhausted dust and generated sinter products were collected and subjected to PCDD/F and PCB analysis. Statistical analysis was applied to assess correlations between properties of iron ores and exhausted dioxin emissions, identifying key contributors to dioxin formation during sintering process. Results showed that Fe in iron ores was positively and significantly related to PCB 114 formation in dust and confirmed its co-catalytic effect on dioxin formation. Concentrations of Al, Ti and Cl in iron ores greatly increased PCDD/F and PCB emissions in the sintered products compared to dioxins in dust samples. The S levels and density of iron ores were highly related to the increasing PCDD/F and PCB emissions in both sinter and dust samples. By contrast, concentrations of Si in iron ores played a significant role in decreasing PCDD/F and PCB emissions in both sinter and dust samples. This study also confirmed the optimum size (< 1 mm–2.59 mm) for iron ores, which helps reduce dioxin emissions without affecting the quality of iron and steel-making products.

Research on Quality Control of Ore Processing Based on Xgboost and Decision Tree Algorithm

Improving the quality of ore processing can directly or indirectly save non-renewable mineral resources and the energy required for processing, thus promoting energy saving and emission reduction and helping to achieve the goal of "double carbon". Ore processing is a complex process, in which voltage, water pressure and temperature, as important factors affecting ore processing, directly affect the quality of ore products. In order to explore the influence of temperature and other factors on ore quality and qualification rate, the corresponding model is established to solve the model of predicting four product quality indexes by system temperature, and fully consider the influence of other uncertain factors to predict the highest possible product quality index at similar temperature.

Methodological substantiation of the choice for optimal modes of equipment operation during the stage-wise concentrate removal in iron ores beneficiation

The urgent task of improving the quality of iron ore concentrates was studied. We propose to use the stage-wise removal of the concentrate by combining fine screening, regrinding, and magnetic-gravity separation. Exemplified by magnetite ore from the Stoilensky GOK, a scientific and methodological approach to the search for optimal separation parameters and modes was substantiated. It includes several stages: studying the particle size distribution and release of useful components in the feed product to select classification parameters; a series of experiments on grinding oversize products to diverse sizes; beneficiation of the obtained products by MG separation. To select the optimal parameters of ore preparation, an analysis of the beneficiation efficiency was used, which is calculated according to the Hancock – Luyken criterion. The results of the research are experimental dependences that connect the process parameters of beneficiation with those of fine vibratory screening. For the studied ferruginous quartzite ore processed at the Stoilensky GOK, the obtained dependences can be described by a second-order polynomial with a high accuracy of approximation. The best performance is achieved with a particle size of 0.1 mm: Fetot content in the concentrate is 69.7 %, recovery is 85 %, classification efficiency is 80.4 %. The top size of the product in this case is 0.076 mm, which corresponds to 70-73 % grinding size of –0.045 class.

Conceptual structure of on-line information and control system toward stabilization of ore flow quality

Underground mineral mining operations in the Norilsk Regions currently involve some essential changes connected with the requirement to maintain the production output at the wanted level and at demandable safety. In the meanwhile, the quality characteristics of minerals produced gradually worsen. In such situation, it is necessary to find a cardinally new approach to improving the crude ore quality by stabilizing composition of ore flow in the course of mining. The article discusses stabilization of ore composition in underground mines via modernization of information and control systems as a case-study of copper&ndash;nickel ore deposits in the Norilsk Region. The conceptual structure of the information and control system aimed at the ore flow quality stabilization is described. Such information and control system structure for the ore flow quality stabilization should provide all production control units with prompt and reliable data on the ore quality and its stability both for ore in situ and produced. The flowchart of the information acquisition, transfer and processing with the subsequent elaboration of a plan of strategic and tactical actions is critical and can, in the long view, become a mighty ore flow stabilizer capable effectively and considerably reduce variability of produced ore composition in the overall ore flow in a mine. The developed package of managerial, engineering and production activities makes the ore flow quality stabilization a controllable process. Its implementation allows enhancing technological efficiency not less than by 2 times, which can greatly improve performance in the whole mining and metallurgy sector.

Mineralogy and Geochemistry of the Asanje Iron Ore Deposit within the Mayamaya-Hombolo Belt, Dodoma Region, Central Tanzania

This paper presents the mineralogy and chemical composition including iron ore impurities to ascertain its suitability for industrial applications. The Asanje iron ore deposit is hosted in Precambrian volcano-sedimentary rocks in the Mayamaya-Hombolo Belt in Dodoma region, within the Lake Nyanza Superterrane. Iron ores are found in two parallel ridges trending NW-SE. Ridge I occurs as vein and banded hematite-type ore and Ridge II as massive-type ore. A total of 24 ore samples were analysed for major and trace elements by XRF and petrographic studies by optical microscopy and XRD. The XRD results revealed that hematite and goethite are the main components and quartz is the gangue mineral in the iron ores. The XRF data shows the Fe2O3t content ranges from 20.8 to 87.3 wt% with an average of 52.7 wt%. The average concentrations in wt% of impurities such as SiO2, Al2O3, P2O5 and S are 37.9, 0.9, 1.2, and 0.2, respectively. By comparison, Ridge II has greater iron content (30.5–87.3 = Avg. 64.66 wt% Fe2O3t) than Ridge I (20.8–78.22 = Avg. 48.68 wt% Fe2O3t). Based on the chemical composition, the quality of iron ore is categorised as low to medium grade, and can be used in metallurgical and cement industries.&#x0D; Keywords: Mineralogy, Geochemistry, Asanje Iron ore deposit, Mayamaya-Hombolo Belt, Tanzania

Automation of ore quality management in quarries

Purpose. Formation of a realistic assessment of the prospects for the introduction of automated ore extraction systems and quality control in the activities of modern mining enterprises. Methodology. The basis of the methodological approach in this study is a combination of system analysis of various aspects of automation of management processes of ore quarrying, with an analytical investigation of the prospects for optimising ore mining processes in quarries using modern methods of automation and digitalisation. Findings. A systematic analysis of various aspects of automation of ore mining management processes by quarry method was performed. The most promising areas of quarry development in order to obtain ore raw materials of the highest quality were identified. A scheme showing the systems of methods for managing the quality of ore mined by the mining method at the mining enterprises was presented. In addition, the scheme of automation of ore quality management processes extracted in quarries was presented and analysed. Originality. A real assessment of the prospects for the introduction of automated systems of ore mining and quality control in the activities of modern mining enterprises has been formed. Practical value. The results of the research can be used as a basis for training specialists in the field of mining industry, whose professional responsibilities include solving issues of ore mining in a quarry way.

Monitoring of Iron Ore Quality through Ultra-Spectral Data and Machine Learning Methods

Currently, most mining companies conduct chemical analyses by X-ray fluorescence performed in the laboratory to evaluate the quality of Fe ore, where the focus is mainly on the Fe content and the presence of impurities. However, this type of analysis requires the investment of time and money, and the results are often available only after the ore has already been sent by the processing plant. Reflectance spectroscopy is an alternative method that can significantly contribute to this type of application as it consists of a nondestructive analysis technique that does not require sample preparation, in addition to making the analyses available in more active ways. Among the challenges of working with reflectance spectroscopy is the large volume of data produced. However, one way to optimize this type of approach is to use machine learning techniques. Thus, the main objective of this study was the calibration and evaluation of models to analyze the quality of Fe from Sinter Feed collected from deposits in the Carajás Mineral Province, Brazil. To achieve this goal, machine learning models were tested using spectral libraries and X-ray fluorescence data from Sinter Feed samples. The most efficient models for estimating Fe were the Adaboost and support vector machine and our results highlight the possibility of application in the samples without the need for preparation and optimization of the analysis time, providing results in a timely manner to contribute to decision-making in the production chain.

Prediction of ore flow quality in a potash mine with regard to the ore face-to-shaft haulage logistics

The industrial know-how, analytical estimation and special experimentation proves that reduction in quality variation of the ore feed for processing can essentially raise productivity and improve final product quality at cheapening of the production at the same time. In pota sh production, the ore quality stabilization by the potassium content criterion enables a high economic profit owing to the increased recovery of the useful component, reduced consumption of chemical agents, saving of power and fuel, decreased losses of KCl with tailings, deloading of salt dumps and tailings ponds and, finally, the environmental destressing. Alongside with the technological blending of ore flow (reclaiming rooms, reservoirs, warehouses, etc.), there are potentially much cheaper managerial approaches. The quality control method includes the use of certain data acquisition, transfer and interpretation facilities arranged underground, relevant software support, as well as control units to operate the mine logistics. At the present time, the level of automation at Belaruskali meets all requirements imposed on the quality control of ore flow to outlet shaftAt the Mining Department of the Belarusian National Technical University, the service simulation procedure is developed for mine faces with various heading and cutting machines in specific geological conditions (mineral seam structure, mineral quality) and geotechnical conditions (seam thickness, cutting head width, face advance velocity, mining flowsheet, downtime duration, etc.).

Biogeochemical Redox Processes Controlling the Element Cycling: Insights from Karst-Type Bauxite, Greece

The occurrence of very-high-grade bauxite ores of karst-type deposits resulting from Fe-leaching is of particular importance, because they are widespread in the Mediterranean metallogenetic province and result in the natural beneficiation of the ore quality. The present study focuses on mineral transformations and variations of major and trace elements, including platinum-group elements (PGE) and mineral chemistry along a bauxite profile from the Parnassos-Ghiona deposit, Greece underlying a fault. The most salient feature of the multicolor ores (grey–whitish, yellowish, deep red, deep grey to brown-red color, from top to bottom) is their association with fossilized and present-day microorganisms, which, by their reducing and/or oxidizing activity, catalyze redox reactions and provide nucleation sites for the precipitation of secondary minerals. Texture relationships between mineral and variations in the mineral chemistry, suggesting the sequence in their formation, indicate a multistage evolution. The recorded compositional variations show that the Al enrichment is accompanied by increase in the TOC, As, Pd and U, and chondrite-normalized REE patterns exhibit a similar trend and positive Ce anomalies. A lower (Pt + Pd) content and higher Pd/Pt ratio, ranging from 1.0 to 5.5 in the bauxite profile compared to those in Fe-Ni laterite deposits with the Pd/Pt ratio ranging from 0.1 to 0.68, reflect the higher solubility and mobility of Pd compared to that of Pt, and differences in their origin and genesis. A positive correlation between Pd and As and the elevated As content (up to 960 mg/kg) in multicolor ores compared to brown-red samples (average 10 mg/kg As) confirms their mobilization and redeposition.

Rescheduling Plan Optimization of Underground Mine Haulage Equipment Based on Random Breakdown Simulation

Due to production space and operating environment requirements, mine production equipment often breaks down, seriously affecting the mine’s production schedule. To ensure the smooth completion of the haulage operation plan under abnormal conditions, a model of the haulage equipment rescheduling plan based on the random simulation of equipment breakdowns is established in this paper. The model aims to accomplish both the maximum completion rate of the original mining plan and the minimum fluctuation of the ore grade during the rescheduling period. This model is optimized by improving the wolf colony algorithm and changing the location update formula of the individuals in the wolf colony. Then, the optimal model solution can be used to optimize the rescheduling of the haulage plan by considering equipment breakdowns. The application of the proposed method in an underground mine revealed that the completion rate of the mine’s daily mining plan reached 83.40% without increasing the amount of equipment, while the ore quality remained stable. Moreover, the improved optimization algorithm converged quickly and was characterized by high robustness.

Choosing a concentration process for Norilsk-1 disseminated ores to be implemented at the new Concentrator Plant and substantiation

1948 saw commissioning of the Big Concentrator Plant that processed ore from the Norilsk-1 deposit. In 1966, a separate section (Line 2) of the revamped plant started to process Talnakh ores. Due to continuous optimization of its concentration technology, Norilsk Concentrator Plant witnessed active development and expansion for many decades. In line with the Development Strategy adopted by MMC Norilsk Nickel, the development plan of Medvezhiy Ruchey foresees further expansion of the mining capacity. By 2027, after the Norilsk-1 project has been implemented, Zapolyarny pit is expected to supply up to 9 mln t/year of disseminated ore. In 2020, an important strategic decision was made to build a new concentrator plant in Norilsk. Using a composite core sample, Gipronikel Institute carried out a laboratory study and a number of processing schemes was identified that would serve the purpose in the best way. A series of pilot tests followed, and it was established that any of the processing schemes selected would deliver its benefits. As a result of joint effort taken by the process designers together with Medvezhiy Ruchey, Science and Technology Directorate of MMC Norilsk Nickel&rsquo;s Polar Division, Norilsk Concentrator Revamp Project Office of NN Development and MMC Norilsk Nickel&rsquo;s Production Department, the Company leadership decided that a flexible process should be introduced for the concentration of Norilsk disseminated ores. The equipment selected and the flexibility of the processing circuit will enable to use one of the three concentration schemes and to produce selective copper and nickel concentrates of varying quality or collective concentrate. Due to adoption of the flexible processing scheme, Norilsk Concentrator Plant 2 will be able to easily adapt to the changing quality of feed ore in the future, to the actual configuration and production schedule of Nornickel&rsquo;s metals division, as well as to the global market demand in general. Other contributors to this research paper include L. S. Lesnikova, M. S. Datsiev (MMC Norilsk Nickel&rsquo;s Polar Division).

Operation of autogenous smelters at Nornickel’s Polar Division when processing raw materials with low energy potential

Because high-grade deposits of sulphide ores are gradually being depleted, the processing industry has to deal with poorer quality ores. To maintain the concentration efficiency, ores have to be ground more thoroughly. At the same time, the quality of the resulting concentrates is affected by the need to maintain certain recovery by concentrator plants. Consequently, low-quality raw materials are fed in the smelters, both in terms of chemical and phase composition and the size distribution. Therefore, the problem of processing such materials is gaining relevance, entailing the need to optimize both the production processes and the equipment involved. This paper examines the chemical, phase and material compositions of the products present in the charge fed in the furnaces of Nadezhda Metallurgical Plant and Copper Plant operated by Nornickel&rsquo;s Polar Division. It also looks at the final products, performs a retrospective analysis of their composition and considers their use. The paper reviews a large array of statistical data (from 2007 till now) to understand how the composition of the concentrates and the charge tended to change and how it influenced the autogenic performance of the process. The conducted study and the performance analysis of the both furnaces handling such materials indicate that autogenous smelters of various types can be adjusted to the changing feed material. This could also help designers make informed decisions regarding the choice of furnaces for new smelters.

The technology of mining tungsten-molybdenum ore of Slepaya Zalezh at Tyrnyauz deposit

Introduction. The article considers the issues of base ore effective mining at the Tyrnyauz tungsten-molybdenum deposit with different methods for filling man-made voids. The objective is to substantiate the reduction in expenditure on the ore-hosting rock mass state control by using tailings to prepare the backfill blends Methods of research. The complex of studies includes the study of engineering and geological conditions of development, the study of the properties of hardening mixture components, the theoretical justification of rock mass stability control methods, and the proposed solutions evaluation. Laboratory studies are carried out on samples made of equivalent and optically active materials. Physical and mechanical properties of rocks and blends are determined using the accepted methods, results are processed by mathematical statistics methods. Results. Ore-hosting rock mass states are analyzed when using a development system with open or filled unbound material. The ore mining technologies type designs by the criterion of rock mass stress control is proposed. The results of modeling the methods of fields development are presented, with and without voids filling, as well as a mathematical model construction and calculation in Maple. The optimal parameters of lost reserves dredging are calculated. The equivalence of qualitative indicators of losses and other field development efficiency indicators has been established. The results of modeling various technologies with different degrees of void filling are given. It is shown that ore loss and dilution mitigation, when optimizing the rock mass state control, compensates for the costs of hardening mixtures. Conclusions and scope of results. Field development without void filling increases losses and dilution to the limit of economic feasibility. There are equivalent ratios between ore quality indicators and other technology indicators, which are the basis for improving the indicators of the lost ore reserves extraction. The obtained results may be in demand when modernizing technologies for the development of solid metal-containing mineral raw materials.

Лабораторні дослідження комбінованого методу зневоднення внутрішніми джерелами теплоти в умовах електричного нагріву

The constant deterioration of the quality of iron ore necessitates the processing of hard-to-enrich minerals that require deep enrichment, and complicates dehydration. Coal processing plants widely use processes carried out in aquatic environments, during which, along with the separation of mineral impurities in the coal remains a significant amount of ballast - water. Therefore, the final operations in the enrichment process are mechanical and thermal dehydration of coal enrichment products, primarily coal concentrates and sludges. The main difficulties are the drying of flotation concentrate (0…0,5 mm) and fine concentrate (0,5…6 mm), which retained after mechanical dehydration residual humidity of 23…27&nbsp;% and about 13&nbsp;%, respectively, which necessitates additional heat drying, the quality of coal concentrate, fuel consumption, energy and metal consumption of the process depend on the method and hardware design. The use of thermal drying for humidity adjustment is associated with a sharp increase in investment and consumption of scarce energy, which in today’s raw materials market and the situation in the economy are impractical. Dehydration by filtration on vacuum filters, which has become widespread in concentrators, does not allow obtaining enrichment products with conditioned humidity. At the raised humidity of concentrate expenses for its transportation to the consumer increase, and in the winter time it’s freezing in railway cars is possible. The development of effective methods for drying and heat treatment of dispersed materials is becoming important in practice due to the high requirements for the quality of finished products and the need to move to energy- and resource-saving technologies. Dehydration of sludge sediments is a big problem, because the existing filtration methods are not very suitable for this. Thus, the establishment of patterns of dehydration of finely dispersed materials is an urgent scientific task.

Understanding the co-relationships of variables and improving product quality and productivity of DRI in rotary kiln

Sponge Iron manufacturing process is an alternative process to manufacturing of Steel through blast furnace route. Sponge Iron is also widely known as Direct Reduced Iron (DRI). As the name suggests direct reduced iron plant utilizes the method of solid-state reduction of Iron Ore to Iron. The reduction process is based on both exothermic and endothermic reaction concerning generation of enormous heat by the use of Coal as the source of Energy input to the process. The main raw materials for the process are Iron Ore, Coal and dolomite. Dolomite is mostly used as a de-sulphurization agent. These industries face many challenges with respect to quality & productivity because of frequent variation in raw material quality (both physical and chemical) of Iron Ore, Coal and dolomite. This variation in the raw materials affect the chemical reactions inside the rotary kiln and which in turn impact the quality and thereby productivity. This process is also associated with generation of solid wastes, which always creates opportunity for improving the efficiency in operation. So also, understanding the co-relationships of input parameters plays an important role in process optimization to reduce losses and thereby improve productivity.