Properties Of Ore Research Articles

Effects of water immersion on the pore structure and thermodynamic properties of sulfide ores

Effects of water immersion on the pore structure and thermodynamic properties of sulfide ores

Research into mechanical properties of ore and rocks in the ore deposits with assessment of the mass stress state natural field

Purpose. The research aims to conduct a comprehensive study of the mechanical properties of ores and rocks within the Zhilandy Group field, as well as to assess the natural field of mass stress state to solve geomechanical problems in optimizing mining operations. Methods. To determine the boundary conditions when measuring the stress-strain state of the mass, a complex methodology is proposed, including stress measurements using hydraulic fracturing methods of the wells and determining the physical-mechanical properties of rocks. Five rock probes have been tested. Twelve tests (six tests in natural and six in water-saturated states) have been conducted for each probe. Findings. Hydraulic fracturing tests at the metering stations show significant tectonic stress due to the shape of structural folds and the mass fracturing. It has been revealed that the hard rock mass is characterized by non-uniform fracturing. It is of tectonic origin and averages between 10-15 and 15-25 fractures per meter for different lithological varieties. The maximum horizontal stress at the stations is oriented along an azimuth of 70° ± 10. Originality. The influence of water saturation on the reduction of strength and deformation characteristics of rocks has been determined for the conditions of the Zhilandy Group field, which shows significant variations depending on the rock type. Especially important is the revealed fact of a significant decrease in uniaxial compression and uniaxial tensile strength, as well as a decrease in Young’s modulus and cohesion factor. Linear dependences of stresses occurring with depth have been obtained from the measurement results. Practical implications. The results obtained are of significant importance for the mining industry. Understanding the extent of reduction in strength characteristics during water saturation and assessing the natural field of the stress mass state allows more accurate prediction of rock behavior.

Seasonal variation in metabolic profiles and microbial communities in a subarctic ore processing plant.

The mining industry strives to reduce its water footprint by recycling water in ore processing. This leads to build-up of ions, flotation chemicals and microbial biomass, which may affect the process. The Boliden Kevitsa mine in Northern Finland is exposed to seasonal change and recycles up to 90% of the process water. We studied the variation in size, composition and putative functions of microbial communities in summer and winter in the ore processing plant. The raw water, Cu and Ni thickener overflow waters had statistically significantly higher bacterial numbers in winter compared to summer, and specific summer and winter communities were identified. Metagenomic analysis indicated that Cu and Hg resistance genes, sulphate/thiosulphate, molybdate, iron(III) and zinc ABC transporters, nitrate reduction, denitrification, thiosulphate oxidation and methylotrophy were more common in winter than in summer. Raw water drawn from the nearby river did not affect the microbial communities in the process samples, indicating that the microbial communities and metabolic capacities develop within the process over time in response to the conditions in the processing plant, water chemistry, used chemicals, ore properties and seasonal variation. We propose that the microbial community structures are unique to the Boliden Kevitsa mine and processing plant.

Physical Properties of Goethite Ore–Carbon Composite Pellets as a Potential Feed for Cast Iron Production

Physical Properties of Goethite Ore–Carbon Composite Pellets as a Potential Feed for Cast Iron Production

A case study on the recovery of unevenly embedded particle size in high-carbon chalcopyrite using an alkyne-based thioester collector: Flotation processing and adsorption mechanism

The difference in chalcopyrite's primary ore-hosting rocks (dolomite and carbonaceous slate) in the Democratic Republic of the Congo results in an extremely uneven grain size distribution. Additionally, the presence of 2.21% organic carbon in the gangue impacts flotation efficiency. To address these challenges, ore properties were analyzed using the Mineral Liberation Analyzer (MLA), X-Ray Diffractometer (XRD), and microscopy. Flotation process was modified to incorporate a "middlings regrinding" processing, utilizing PDEC (an alkyne-based thioester collector, prop-2-yn-1-yl diethylcarbamodithioate) as the collector for experimental studies. Density Functional Theory (DFT) calculations elucidated the interaction mechanism of PDEC on chalcopyrite's surface. The MLA analysis indicates that chalcopyrite is mainly found in medium to fine grains, with the presence of fine-grained copper minerals smaller than 0.04mm accounting for 16.29% of the sample. This implies that these minerals require fine grinding for effective separation. Despite interference from organic carbon, PDEC demonstrates remarkable selectivity and efficiency in chalcopyrite flotation. By employing the "middlings regrinding" flotation method, a concentrate with a Cu content of 26.79% and a recovery of 87.88% was achieved, representing an increase of 0.17% in Cu grade and 4.09% in recovery rate compared to the conventional flotation process. DFT analysis demonstrates that the S 3p orbitals in carbon-sulfur double bond of PDEC and the C 2p orbitals in its acetylene group significantly affect its collection efficiency, engaging in hybridization with the Fe 3d orbitals on the surface of chalcopyrite, thereby facilitating a robust bonding interaction.

Iron ore grade's impact on uniaxial compression behavior and acoustic emission characteristics

The mechanical properties of iron ore are influenced by various factors, including its grade, which consequently impacts stope stability and equipment efficiency in the mining process. In order to explore the influence and mechanism of grade on these properties, handheld XRF testing was conducted to determine the grade of iron ore samples ranging from 28% to 40%. Subsequently, the acoustic emission method was employed to acquire signals during the uniaxial compression tests. Additionally, scanning electron microscopy was utilized to examine the fracture surface, for performing a microscopic analysis of the influence mechanism of grade on the mechanical properties of iron ore. The results revealed that lower-grade iron ore exhibited larger transverse deformation, with a corresponding dominance of tensile failure. This observation aligned with the AF-RA value (Parameters of reaction crack type), which depicted a shift in the types of microcracks generated during the compression process from tensile cracks to shear cracks with the increasing grade. The content of gangue minerals diminishing as the grade increased. Consequently, the location of the cracks transitioned from the primary failure Through the gangue minerals to the primary microcracks in metallic minerals, resulting in a higher occurrence of acoustic emission events during the early loading stage and the development speed of microcracks accelerates during the loading process. The dominant frequency (Parameters of reaction crack size) of the acoustic emission signal increased from 150 kHz at a grade of 28% to 264 kHz at a grade of 40%, accompanied by a linear decrease in the proportion of low-frequency signals. The b value (indicator for quantifying the degree of damage) demonstrates a decrease with increasing grade. Overall, the content of metal minerals in the iron ore increased with the grade, resulting in polymerization. However, the influence of crack propagation on the overall strength of iron ore remained relatively minor. Macroscopically, the uniaxial compressive strength increased almost linearly with the iron ore grade.

Study on the Effect of Liberation Properties of Phosphate Ore with Different Particle Sizes on Flotation at Different Grinding Degrees

Study on the Effect of Liberation Properties of Phosphate Ore with Different Particle Sizes on Flotation at Different Grinding Degrees

Design of Three-Dimensional Electrical Impedance Tomography System for Rock Samples

Research on the electrical properties of rocks and ores plays a crucial role in the development of geophysical electromagnetism methods. However, currently available instruments suffer from high power consumption, a limited number of electrodes, inaccurate measurements, poor portability, and a limited ability to measure the electrical parameters of rocks and ores. To address these issues, this paper presents a three-dimensional electrical impedance tomography system for rock samples with high-density microelectrodes based on an Android system and STM32 microcontroller. The system features high observation accuracy, dense electrode arrays (with 384 current and potential electrodes), flexible electrode selection, user-friendly human–computer interaction, good stability, and real-time performance. Powered by a single power bank, the entire instrument can be controlled and monitored wirelessly via Bluetooth and Wi-Fi technology using an Android smartphone. Additionally, the system not only enables accurate measurement of electrical parameters, but also facilitates the generation of three-dimensional impedance imaging of specimens via inversion algorithms after data export, allowing for a comprehensive understanding of the electrical properties of rocks and ores. This system holds great potential for future research in this field.

An overview of halloysite mineral

Halloysite is a type of clay mineral found in the kaolin group together with kaolinite, dickite, and nacrite minerals. Kaolinite is the most common mineral in this group, while dickite, nacrite, and halloysite are rarer. Although halloysite is primarily used in ceramic production, application in other industries is increasing and gaining economic value due to its unique properties. The use of halloysite is determined by the degree of purity and the properties of the nano-sized tubular structure. Naturally obtained halloysite mineral has a key position in the field of nanotechnology due to its unique physicochemical properties originating from its tubular structure. Also, due to its reserves in many parts of the world, halloysite is a more economical material for the sectors compared to artificially produced nanomaterials. And, they find many different application areas because of these features (morphological and physicochemical). Halloysite reserves known in Türkiye are located in the Çanakkale and Balıkesir regions. Although there are many useful studies on halloysite in different, additional studies are needed to understand the nano-sized properties of halloysite ore and to ensure its use that will provide maximum benefit. This study aimed to contribute to the studies on halloysite in terms of literature by compiling studies on the characterization of halloysite minerals, reserve information, physicochemical properties, enrichment methods, and usage areas.

A Study on the Influence of Drying and Preheating Parameters on the Roasting Properties of Limonite Pellets

In this experiment, a pellet preparation method was investigated to study the drying, preheating, and roasting properties of limonitic iron ore from a plant in Yunnan. The aim was to improve the subsequent iron-making process of limonitic iron ore and make it a substitute for sintered ore. This substitution would reduce the amount of blast furnace slag in the iron-making process. Bentonite is commonly used as a primary binder in many pelletizing plant operations. However, its excessive usage leads to a higher risk of slagging and coking in the furnace. In this paper, we aim to decrease the quantity of bentonite added, enhance the iron content in the pellets, and reduce impurities to improve the grade of limonite pellets. The results show that the optimal drying, preheating, and roasting temperatures of limonite pellets are 200 °C, 700 °C, and 1250 °C, respectively, and the optimal roasting time is 20 min, when the diameter of the pellets is 8–13 mm. The compressive strength of limonite pellets with the addition of 1.5% bentonite was the highest, meeting the demands of a general blast furnace, based on which the iron grade of limonite pellet ore was increased by 10.63%.

Determination of Physical and Geomechanical Properties of Black Shale Hosting Lead and Zinc Ore in Eyingba, Ebonyi

This study was conducted to investigate the physical and geo-mechanical properties such as specific gravity, porosity, uniaxial compressive strength (UCS) etc. of shale, hosting lead and zinc ore in Enyigba, Ebonyi State, Nigeria. The strength properties of the black shale were analyzed because the variability in the strength of rock masses must be properly accounted for, to determine their utility in engineering design. Several tests were carried out on the intact shale samples, and the results were converted to bulk mass strength values using the Hoek–Brown criterion. The results showed that the UCS of the black shale ranged from 38.3 to 43.7 MPa for a geological strength index (GSI) value of 75; and from 54.2 to 60.4 MPa for a GSI value of 80. The specific gravity was 2.89 while the bulk density and porosity values were 290.3 kg/m3 and 15.56% respectively. Also, it was determined that there is a strong correlation between the UCS and specific gravity of the rock, with negligible levels of correlation, both positive and negative, between the UCS and the other mechanical properties examined. In conclusion, the black shale sample from Enyigba is characterized as a medium to hard rock that is suitable for engineering and mining projects.

Features of electrical conductivity at high temperatures of complex titanomagnetite ores from the Gusevogorsky deposit

Relevance is determined by the search and selection of the most information-intensive characteristics and physical properties of complex titanomagnetite ores in connection with the need for scientifically based criteria for their detection, quality assessment during selective mining and selection of optimal enrichment technology. Research methodology. To study the electrical properties, samples in the shape of a cube with an edge of 0.02 m were used. The measurements were carried out in an open system at atmospheric pressure. Electrical resistance was measured with a two-electrode setup every 10 degrees in the temperature range 20–800 ºC. Heating rate 0.066 deg/s. The measuring device is an E6-13 teraohmmeter with a dynamic range from 10 to 1014 Ohms and a relative measurement error from ±2.5% to 4% at the end of the range. Results. A collection of samples of complex titanomagnetite ores from the Gusevogorsky deposit (Northern quarry) was studied using physical, mineralogical and petrographic methods. Functional connections have been established between the electrical parameters of high-temperature electrical conductivity (Eₒ – activation energy, lg Rₒ – the so-called electrical resistance coefficient), the value and nature of the electrical resistance lg R in the temperature range 20−800 °C of the studied samples of complex ores with their structural and textural features and mineral composition. Based on structural and textural features, mineral composition and electrical parameters, the studied samples are clearly divided into three groups. Conclusions. The presented results, in combination with other physicochemical parameters, can be used as a reliable indicator of rapid assessment of the material being studied. Significant differences in the electrical parameters of titanomagnetite ores provide additional information about their quality. In combination with other methods, we hope for the possibility of using these parameters in the selective extraction of ores that require different enrichment regimes.

Study on photofluorescent uranium ore sorting based on deep learning

Uranium ore stands as a vital source of energy, and the process of ore sorting serves to segregate valuable uranium ore from its less valuable counterparts. This not only enhances the intrinsic ore grade but also mitigates the challenges associated with subsequent refining processes, thus leading to substantial resource cost savings. Consequently, the necessity of pre-sorting uranium ore becomes evident. While prevailing X-ray-based ore sorting technology remains at the forefront, the quest for a more efficacious method to sort uranium ore remains ongoing. This study harnesses the inherent photofluorescence properties of uranium ore by subjecting it to ultraviolet light, inducing the emission of a vibrant green fluorescence. Consequently, we propose a novel sorting technique founded on photofluorescence, augmented by deep learning to enhance the precision and categorization of uranium ore images. Two distinct models, the Convolutional Neural Network (CNN) model and the Transformer model, are developed in tandem. Empirical findings underscore the superiority of the Swin Transformer model, with training accuracy, validation accuracy, and classification rate registering at 0.9780, 0.9719, and 96.4 ms/it, respectively, surpassing the performance of alternative models like Alex Net and Res Net 34. Furthermore, the study employs visual aids, including channel visualization diagrams, confusion matrices, and Grad-CAM diagrams, to elucidate the operational intricacies of the model in the sorting of photofluorescent uranium ore images. This allows for an insightful analysis of the characteristics that influence classification weights. The potential applications of this method are indeed substantial, opening new avenues for uranium ore exploration and utilization.

Mineralogical Studies of the Tanjung Iron Mine in the Bone, South Sulawesi: Implication for AMD Generation

The iron ore of abandoned iron mine at the Tanjung Arae in Bone Regency has been investigated with the aim to analyze mineralogical characteristics and its potential for generating acid mine drainage (AMD). Mineralogical properties of the iron ore were analyzed using optical microscopy and X-ray diffraction (XRD) methods. Results of analysis reveal that the samples are dominated by iron oxide minerals such as magnetite, hematite and goethite. Other minerals are also present such as quartz, birnessite, pyrite and chalcopyrite. Mostly pyrite [FeS2] and chalcopyrite [CuFeS2] have been undergoing alteration which are characterized by weathering rims of those crystals and transformed into goethite and hematite. It is shown that the existence of pyrite [FeS2] and chalcopyrite [CuFeS2] may have significant roles in triggering the generation of AMD.

Characterisation of Ore Properties for Geometallurgy

The successful implementation of geometallurgy largely depends on the continuous collection of high-quality, multi-scale, multi-dimensional quantitative data on the geology, geochemistry, mineralogy, texture, and physical properties of an orebody. This can then be used to build and improve, amongst other things, ore deposit models, comminution strategies, waste management, and downstream mineral processing and extractive metallurgy routes. The present contribution provides a brief overview of the key types of data collected, and analytical techniques used, in geometallurgical programs. It also highlights important developments that are currently underway, which may generate a significant impact in the near future.

Research Status and Challenges of High-Purity Quartz Processing Technology from a Mineralogical Perspective in China

Quartz deposits are widely dispersed in nature, but the presence of ore bodies capable of yielding high-purity quartz is exceedingly rare. As a result, the effective purification and processing of high-purity quartz from natural siliceous materials has emerged as a prominent area of research within the non-metallic mineral processing field. This article offers an overview of the current state of research and its limitations in quartz purification and processing technology in China, including the characteristics of quartz mineral resources, the geological origins of ore deposits, impurity forms in ores, and purification techniques. Drawing from examples of five distinct types of quartz ores—vein quartz, powder quartz, quartzite, granitic pegmatite, and pegmatitic granite—we delve into the inherent properties of quartz deposits, ores, and minerals from a mineralogical perspective, establishing their link to purification and processing methodologies. A fundamental challenge restraining the advancement of the high-purity quartz industry is the absence of criteria for evaluating and selecting high-purity quartz raw materials. Existing purification technologies grapple with issues such as intricate single mineral liberation, substantial acid consumption, high energy requirements, and protracted processing procedures. The lack of mineralogically based deep purification techniques presents a hurdle to the development of the high-purity quartz industry. Given the diversity of ore types, the pursuit of knowledge-driven design and the development of economically efficient, environmentally friendly, and streamlined new technologies for tackling the complexities of the purification process may constitute the future direction of our endeavors.

Insight into Crystalline Structure and Physicochemical Properties of Quartz-Carbon Ore

Composites made from carbon and nanominerals show great potential for thermal phase change materials, environmental water treatment, and biomass conversion. In 2019, a micro and nano-quartz-carbon ore was discovered in Feng-cheng City, Jiangxi Province. The study of the structural and physicochemical changes of quartz-carbon ore (QZC) during calcination is essential for the preparation of QZC-based composites and to broaden their application areas. Firstly, the SiO2 crystal structure evolution of QZC during calcination was investigated using in-situ X-ray diffraction (XRD), 29Si magic-angle sample spinning nuclear magnetic resonance (MAS NMR), and Fourier transform infrared FTIR spectroscopy. Then, the changes in carbon during calcination were investigated using Raman spectroscopy, 13C MAS NMR, and X-ray photoelectron spectroscopy (XPS). In addition, changes in the QZC morphology were observed using scanning electron microscopy (SEM) and transmission electron microscopy (TEM) techniques. Finally, the evolution of the physicochemical properties of QZC during calcination was revealed using thermogravimetric (TG), Brunauer–Emmet–Teller (BET), resistivity, thermal conductivity, and zeta potential techniques.

Particle-based characterization and process modeling to comprehend the behavior of iron ores in drum-type wet low-intensity magnetic separation

Drum-type wet low-intensity magnetic separation is a versatile technique traditionally implemented in the mining industry since the mid-19th century. Yet, comprehending the process from a fundamental point of view remains challenging and its implementation still relies on “rules of thumb” that commonly disregard the ore properties and the effects of the operating conditions. This work describes an approach that combines comprehensive particle-based characterization and process modeling to integrate particle properties and equipment characteristics to describe the behavior of an iron ore in a laboratory-scale drum-type magnetic separator. Such a proposal is based on (1) laboratory testing, (2) automated mineralogy for particle-scale ore characterization, and (3) process modeling to compute the particle separation kinetics as a function of the ore intrinsic attributes and the physical principles involved in magnetic separation. This approach proposes the guidelines to obtain early information on the iron ore processing behavior, which represents a promising tool for decision-making at different stages of the beneficiation chain.

Process mineralogical study of U/Th occurrence states and the carrier minerals in refractory tantalum slag

Large quantities of work have been done previously on mineralogical properties and elements extraction of tantalum ores. However, the occurrence states and carrier minerals of U/Th in refractory slag still have not been studied in detail. The objective of this study was to investigate the tantalum slag, in order to determine the distribution and occurrences of uranium–thorium and their carrier minerals. Various techniques were used to detect the slag for chemical compositions, surface morphology and mineral dissociation. The result indicated that the U content was 1.09 × 103 mg/kg and Th was 4.62 × 103 mg/kg, thus the slag had great recovery prospect. Based on diversified characterizations, U was distributed in rare earth minerals as quantities of insoluble tetravalent forms (e.g., UF4, UO2) and a small amount of hexavalent (e.g., UF6, UO3, UO2F2), similarly Th was present in tetravalent state (e.g., ThF4, ThO2). According to AMICS (Automatic Mineral Characterization System) statistical calculation, the carrier minerals of U/Th were fluocerite, monazite and xenotime. The occurrences of U/Th were mainly in adsorption and isomorphism states in carriers, without monomers. There were high proportion of siderite and pyrolusite in slag, and radionuclides had closely relation to rare earth elements and metals. The carrier minerals were predominantly independent grains, some of which were intergrown to Fe-Mn minerals, the rare earth minerals were also associated and symbiotic with each other. By characterizing the U/Th distribution and the properties of carrier ores, this paper provided a theoretical basis for the process of recovering radionuclides from tantalum slag.

Operational optimization of copper flotation process based on the weighted Gaussian process regression and index-oriented adaptive differential evolution algorithm

Concentrate copper grade (CCG) is one of the important production indicators of copper flotation processes, and keeping the CCG at the set value is of great significance to the economic benefit of copper flotation industrial processes. This paper addresses the fluctuation problem of CCG through an operational optimization method. Firstly, a density-based affinity propagationalgorithm is proposed so that more ideal working condition categories can be obtained for the complex raw ore properties. Next, a Bayesian network (BN) is applied to explore the relationship between the operational variables and the CCG. Based on the analysis results of BN, a weighted Gaussian process regression model is constructed to predict the CCG that a higher prediction accuracy can be obtained. To ensure the predicted CCG is close to the set value with a smaller magnitude of the operation adjustments and a smaller uncertainty of the prediction results, an index-oriented adaptive differential evolution (IOADE) algorithm is proposed, and the convergence performance of IOADE is superior to the traditional differential evolution and adaptive differential evolution methods. Finally, the effectiveness and feasibility of the proposed methods are verified by the experiments on a copper flotation industrial process.