Mineral Processing Research Articles

The interplay between job security and motivation: evidence from Tronox KZN sands

Job security and employee motivation are crucial factors that contribute to organizational stability, productivity, and overall success. This study explores the relationship between job security and employee motivation at Tronox KZN Sands, a mining and mineral processing company based in South Africa. Utilizing Social Exchange Theory (SET) as a theoretical framework, the research examines how perceptions of the workplace influence levels of commitment and job satisfaction among employees. Employing a quantitative research methodology, data was gathered from 100 employees through a structured questionnaire, with statistical analysis conducted using SPSS 30 software. It was noted that job uncertainty often arises from economic downturns, industry fluctuations, and organizational restructuring, which can result in diminished motivation and job satisfaction among employees. Additionally, the study identifies demographic variations in perceptions of job security, revealing that younger employees typically express greater concern about job stability compared to their older counterparts. Factors such as workplace support, transparent communication, and opportunities for career development significantly influence the interplay between job safety and employee motivation. Effective communication regarding job stability, investment in employee career advancement, and the promotion of a supportive work environment are essential measures that organizations can adopt. Companies can enhance employee morale, reduce turnover rates, and improve overall organizational performance by prioritizing these strategies. The findings of this study contribute to the broader discourse on the relationship between human resources and workplace dynamics, offering practical insights for policymaking in South Africa's mining regions, as well as for manufacturers and management professionals.

The Concentration of Nickel and Cobalt from Agios Ioannis Laterites by Multi-Gravity Separator

Asbolane is a secondary source of cobalt (Co) and manganese (Mn), essential for battery and alloy production. Enhancing the utilization of low-grade ores, typically containing ~1.2% Co and 14.7% Mn, is vital for conserving high-grade resources. However, fine grinding for such ores presents challenges for conventional gravity separation. This study investigates the effectiveness of the Multi-Gravity Separator (MGS) in processing finely disseminated asbolane ore from Agios Ioannis, Greece. The study was conducted at the Mineral Processing Laboratory of UPC/Bases Manresa. Two size fractions, D80 (−100 +50 µm and −50 µm), were tested under varying drum speeds, tilt angles, and wash water flows. Response surface methodology (RSM) was implemented using Python-optimized (version 3.15) process parameters. The results demonstrate that a concentrate with 2.6% Co and 32.5% Mn can be obtained, achieving 82.1% Co recovery. Independent and multi-objective optimizations confirm MGS as a viable method for recovering Co and Mn from complex low-grade ores, with reduced overgrinding-related energy losses essential for production. The study aimed to implement and enhance low-grade asbolane ore from a feed containing 2.6% Co and 32.5% Mn. Variables were optimized with a multi-objective target, demonstrating their effectiveness.

Geometallurgical Characterization of the Main Mining Fronts of a Zinc and Lead Mine Operation

Geometallurgy is an approach that utilizes predictive models that can support business decisions, mitigate risks, and enhance production efficiency. To develop an accurate geometallurgical model, it is essential to understand the behavior of each lithology within the ore body through geometallurgical testing. In this context, the present study aims to evaluate the performance of bench-scale tests conducted on the main mining fronts of a zinc mine operation located in Brazil. The mineral processing plant was designed to process lead and zinc sulfide ores without material stockpiling, where all ores extracted from the underground mine are immediately processed. The geometallurgical characterization was conducted through the following steps: sampling, crushing, grinding, and flotation. The recovery, concentrate, and tailing contents during the flotation stages of galena and sphalerite were analyzed. A mineralogical characterization using a Mineral Liberation Analyzer (MLA) was performed to assess the degree of particle liberation and mineral associations within the studied mining fronts. The results indicate that a higher degree of pyrite liberation leads to greater metallurgical recovery of mineralized bodies A (breccia-hosted orebody), B (sphalerite-rich doloarenite orebody), and C (upper replaced stratiform orebody). Among these, mineralized body C presents the highest recovery in the zinc and lead stages, with 99.5% and 86.2%, respectively.

Synergistic Leaching of Low-Grade Tungsten–Molybdenum Ore via a Novel KMnO4-Na2CO3-NaHCO3 Composite System Guided by Process Mineralogy

The mineral processing of a low-grade tungsten-molybdenum ore (LGTMO) was investigated to assess the potential of recovering molybdenum (Mo) and tungsten (W). Techniques such as Polarizing Microscope (PM), Scanning Electron Microscopy-Energy Dispersive Spectroscopy (SEM-EDS), Mineral Liberation Analysis (MLA), and Advanced Mineral Identification and Characterization System (AMICS) were employed. The recoverable metals in the ore are Mo (0.158% ± 0.03%) and W (0.076% ± 0.02%). Mo exists in two forms: 63.30% as molybdenite and 36.7% as powellite (CaMoxW1−xO4). W is present as 75.26% scheelite and 24.74% powellite. The complete dissociation rates of molybdenite and scheelite-powellite are 27.14% and 88.87%, respectively. Particles of scheelite-powellite with a diameter less than 10 µm account for 34.61%, while molybdenite particles with a diameter below 10 µm make up 72.73%. Scheelite-powellite is mainly associated with olivine and dolomite, while molybdenite is mainly associated with pyroxene, calcite, and hornblende. Based on the process mineralogy, the mineralogical factors influencing the flotation recovery of molybdenite and scheelite-powellite were analyzed. Finally, a complete hydrometallurgical leaching test was carried out. The optimal experimental conditions are as follows: liquid-solid ratio of 6 mL/g, KMnO4 concentration of 0.015 mol/L, Na2CO3 concentration of 0.12 mol/L, NaHCO3 concentration of 0.024 mol/L, leaching time of 4 h, and leaching temperature of 85 °C. Under these conditions, the leaching efficiencies of Mo and W reach 79.23% and 41.41%, respectively. This study presents a novel approach for the recovery of refractory W and Mo resources in LGTMO while simultaneously providing a theoretical basis for the high-efficiency utilization of these resources.

On the question of extracting valuable components from spent catalyst

ABSTRACT Intensive mining and mineral processing in Kazakhstan have led to the accumulation of over 25 billion tons of industrial waste, including spent catalysts from the oil refining industry. These man-made raw materials often contain valuable metals, such as vanadium, molybdenum, and nickel, which are present in concentrations comparable to or higher than those in natural ores. The industrial exploitation of these resources is critical due to the depletion of high-quality raw materials and the environmental impact of waste accumulation. This research focuses on developing effective technologies for processing spent catalysts, which are rich in vanadium, molybdenum, nickel, and aluminum. The study investigates the physicochemical properties of spent catalysts and the effectiveness of various reagents in extracting valuable components. After carbonate and alkaline leaching of the feedstock, a concentrate with a nickel content of 10.09% was obtained. Nickel extraction from the concentrate was optimized using a reagent mixture of hydrochloric acid, chlorine compounds, and ammonium bifluoride, achieving an 85% extraction efficiency. Based on the results, a conceptual technological scheme for the processing of spent catalysts has been proposed, offering a promising solution for utilizing man-made raw materials in Kazakhstan's oil refining industry.

The Flotation Depression Mechanism of Fluorapatite and Dolomite Using Fulvic Acid as a Green Depressant in Weakly Acidic Conditions

Natural phosphate ores frequently contain calcium–magnesium carbonate minerals as gangue components. Their separation from target phosphate minerals poses significant challenges due to analogous surface characteristics. The flotation differentiation between fluorapatite and dolomite remains a key research focus in mineral processing. In conventional collector systems, selective depressants critically govern separation efficiency, as their interfacial specificity directly determines beneficiation outcomes. The selective depression behavior of fulvic acid (FA) in modulating fluorapatite–dolomite separation efficiency within oleate-dominated flotation systems was elucidated through micro-flotation experiments, complemented by zeta potential measurements, contact angle analysis, Fourier-transform infrared spectroscopy (FTIR), and molecular dynamics (MD) simulations. The findings revealed that fluorapatite and dolomite both exhibit high floatability under NaOl-mediated collector systems in the absence of depressant additives, leading to negligible selectivity in the differential separation of the mineral pair. However, the float of fluorapatite particles in weakly acidic conditions was strongly depressed when a small amount of FA was added as a depressant, while exerting minimal impact on dolomite’s floatability. In binary artificial mixed-mineral flotation systems, under optimized flotation conditions (pH 5.0, 60 mg/L NaOl, and 15 mg/L FA), the concentrate achieved a P2O5 grade of 33.86% with a fluorapatite recovery rate of 92.36%, demonstrating significant selective separation of fluorapatite from dolomite. Subsequent analysis revealed that FA competitively chemisorbs with NaOl on fluorapatite surfaces, selectively reducing the hydrophobicity of the fluorapatite surface and suppressing fluorapatite floatability, thereby enabling effective differential liberation of the mineral pair.

Specific energy reduction in a semi-autogenous grinding mill circuit by an automatic control system

Grinding operations, especially those involving semi-autogenous mills, account for a significant portion of energy use in mineral processing. In this work, we describe the application of an advanced regulatory control strategy in a copper plant aimed at improving energy efficiency through automation. The system combines cascade and feedforward control structures to attenuate variations in the mill load, a key factor influencing energy consumption and process stability. The control scheme was integrated into the plant’s existing automation infrastructure and evaluated through a three-month industrial trial. By shifting from manual to automatic regulation of the feed rate, the plant reduced the influence of process disturbances and maintained more consistent operation. The automated system achieved a 5.84% reduction in specific energy consumption and a 1.90% increase in productivity. These results demonstrate the potential of enhanced regulatory control to deliver measurable performance gains with minimal changes to existing operations.

Advancing sustainable dewatering of fine phosphate tailings: Evaluating xanthan gum, sodium alginate, and carboxymethyl cellulose as flocculating agents.

Advancing sustainable dewatering of fine phosphate tailings: Evaluating xanthan gum, sodium alginate, and carboxymethyl cellulose as flocculating agents.

Using radioactive waste for targeted alpha therapy: Advancing a sovereign Australian supply of 225Ac and 212Pb.

Using radioactive waste for targeted alpha therapy: Advancing a sovereign Australian supply of 225Ac and 212Pb.

Renewable energy applications in mineral processing and mining operations: a bibliometric analysis and systematic literature review

This study presents a bibliometric analysis and systematic literature review of renewable energy applications in mineral processing and mining operations from 2000 to 2024, identifying key themes, trends, and future research directions. Using bibliometric analysis, text mining, and content analysis, the study aimed to: (i) capture the scientific evolution of renewable energy applications, (ii) provide a comprehensive overview of existing literature, and (iii) propose future directions. A total of 198 peer-reviewed articles were analysed from Scopus, JSTOR, and Taylor & Francis databases using the preferred reporting items for systematic reviews and meta-analyses method. In addition to the systematic search, an ad-hoc sampling approach was used, meaning that additional studies cited within key selected articles were manually included, provided they met specific relevance criteria related to renewable energy in mining. The analysis identified four research areas: (1) sustainable development through renewable energy, (2) wind energy prediction using AI, (3) solar energy applications in mining, and (4) energy demand management.

Recovery of Tetrahedrite from Mining Waste in Spain

The present study is part of the Horizon Europe-START project, which aims to recover tetrahedrite-group minerals present in mine dumps to be used as raw materials for the manufacture of thermoelectric devices. The aim of this work is to identify the mining waste facilities selected in Spain for the recovery of tetrahedrite and to outline the mineral processing operations performed on samples from each site to separate and concentrate this mineral. Ore deposits across Spain were selected based on the potential presence of tetrahedrite in their mining waste. A total of five deposits have been sampled, at which subsequent mineral separation and concentration tests have been conducted. A separation flowsheet is proposed in order to extract a high-purity tetrahedrite concentrate. Experimental results indicate two distinct options for separation approaches, depending on a key parameter that proves decisive in the processing of this mineral, which is whether the mineral paragenesis includes siderite. This study has demonstrated the technical feasibility of concentrating minerals of the tetrahedrite group through simple, cost-effective physical separation techniques—specifically magnetic and gravity separation—where the liberation size of the tetrahedrite exceeds 0.063 mm.

Interfacial Mechanisms of O-O Type Chelating Collectors in the Flotation of Copper Minerals: A Density Functional Study

Flotation is a widely used separation technique in mineral processing that relies on surface chemistry to recover valuable metals from low-grade ores. This study presents a theoretical evaluation of O-O type chelating collectors in the selective flotation of copper minerals, emphasizing their interactions at the colloidal and interfacial levels. Using advanced computational methods, key surface chemistry parameters—including adhesion mechanisms, electron density distributions, and binding energies—were analyzed to assess the efficiency and selectivity of these collectors. The findings demonstrate that O-O type chelating collectors establish strong and specific interactions with copper mineral surfaces, enhancing hydrophobicity and improving attachment to air bubbles. Among the studied collectors—Cupferon, Neocupferon, 2-nitroso-1-naphthol, 2,4-pentanedione, Octyl hydroxamate, and 2-Acetyl-acetanalid—Octyl hydroxamate exhibited the highest stability and affinity for Cu²⁺ ions, while 2-Acetyl-acetanalid showed the weakest performance. This study provides fundamental insights into the interfacial mechanisms governing flotation efficiency and offers guidance for optimizing reagent selection. By contributing to the design of more selective and sustainable collectors, these findings support advancements in mineral processing, environmental technologies, and interfacial science.

Experimental Research on Quarry Wastewater Purification Using Flocculation Process.

The flocculation-based purification of quarry wastewater continues to pose a significant challenge in mineral processing and environmental engineering, primarily due to persistent turbidity issues and inefficient floc settling behaviour. In this study, we systematically investigate the synergistic effects of organic and inorganic flocculants to reduce turbidity and improve floc settling performance. Through a series of optimised experiments using polyaluminium chloride as an inorganic flocculant, polyacrylamide as an organic flocculant, and calcium oxide as a pH regulator agent, the treatment efficiency was evaluated. Under the optimal conditions with 200 g/m3 CaO as the regulator agent and 2.5 g/m3 PAC and 12 g/m3 PAM as flocculants, the residual turbidity was reduced to 97.30 NTU, meeting stringent industrial discharge standards and enabling zero-discharge water reuse. Zeta potential measurements, optical microscopy, and DLVO theory collectively elucidated the interfacial interactions between flocculants and mineral particles, with zeta potential revealing electrostatic effects, microscopy visualising aggregation patterns, and DLVO theory modelling revealing colloidal stability, thereby mechanistically explaining the enhanced aggregation behaviour.

Enrichment Regularity of Indium in the Dulong Mineral Processing Plant, Yunnan Province, China

The Dulong deposit in Wenshan, southeastern Yunnan Province, is rich in zinc, tin, and copper resources, accompanied by rare metals such as indium and silver. It is a particularly important indium production base, with reserves of approximately 7000 tons, ranking first globally. Enrichment and recovery of indium-bearing minerals are mainly achieved through mineral processing technology. However, the recovery rate of indium in the Dulong concentrator remains relatively low, and there is an insufficient understanding of its occurrence state and distribution characteristics, resulting in marked indium resource wastage. Here, we conducted a systematic process mineralogy study on indium-bearing polymetallic ore in the Dulong concentrator. The average grade of indium in the ore is 43.87 g/t, mainly occurring in marmatite (63.63%), supplemented by that in silicate minerals (23.31%), chalcopyrite (7.84%), and pyrrhotite (4.22%). The indium has a relatively dispersed distribution, which is inconducive to enrichment and recovery. The substitution mechanism of indium in marmatite was investigated using laser ablation inductively coupled plasma mass spectrometry. This revealed a positive correlation between indium and copper, allowing us to revise the substitution relationship to: ZnxS+Cu++In3+→Znx−2CuInS+2Zn2+ or Znx−1FeS+Cu++In3+→Znx−2CuInS+Zn2++Fe2+. Electron probe microanalysis revealed the presence of roquesite (CuInS2), an independent indium mineral not previously reported from this deposit. Our detailed investigation of the Dulong concentrator mineral processing technology showed that the recovery rate of indium from marmatite is currently poor, at only 48.01%. To improve the comprehensive utilization rate of indium resources, it will be necessary to further increase the recovery rate from marmatite and explore the flotation recovery of indium from chalcopyrite and pyrrhotite.

Research on High-Temperature Resistance of Iron Tailings Concrete

Iron tailings, as industrial solid waste generated during the mineral processing operations, are experiencing a continuous increase in their reserves due to ongoing mining activities. The massive accumulation of iron tailings not only occupies valuable land resources but also causes severe ecological damage to mining areas. The utilization of solid waste materials for the production of recycled aggregate concrete is of crucial importance for the sustainable development of the construction industry. In recent years, research on solid waste-based concrete, particularly focusing on the durability and high-temperature resistance of iron tailings concrete, has advanced rapidly, yielding a series of notable achievements. This paper analyzes multiple articles on iron tailings concrete research, summarizing the existing outcomes and identifying the gaps in the current knowledge base. The objective is to provide a reference for future research endeavors in this domain.

Laser-Induced Surface Vitrification for the Sustainable Stabilization of Copper Tailings

This study introduces CO2 laser surface vitrification as an innovative method for managing copper mining tailings, offering a sustainable solution to critical challenges in mineral processing. This technique transforms tailings into a stable and impermeable layer, immobilizing hazardous metals contained within them. By achieving vitrification at the surface level and operating at temperatures around 1200 °C, the process significantly reduces energy consumption compared to traditional vitrification methods, making it suitable for large-scale applications in remote mining sites. Detailed geochemical and mechanical analyses confirmed the formation of a dense vitreous matrix with high hardness (7.19–7.48 GPa) and reduced permeability, ensuring compliance with stringent environmental regulations. However, the brittle nature of the vitrified layer underscores the need for further research to enhance mechanical resilience. This work positions CO2 laser vitrification as a transformative approach for integrating energy-efficient technologies into mineral processing, addressing key environmental concerns while advancing the sustainable management of mining waste.

Exergy-Based Sustainability Assessment of Gold Mining in Colombia: A Comparative Analysis of Open-Pit and Alluvial Mining

Thermodynamic methods such as exergy analysis enable the evaluation of environmental load (environmental impacts) by quantifying entropy generation and exergy destruction associated with using renewable and non-renewable resources throughout a production system. Based on the principle that environmental impacts occur when exergy is dissipated into the environment, this study applies exergy analysis as a tool for assessing the sustainability of gold mining in Colombia. Two extraction technologies—open-pit and alluvial mining—are evaluated by calculating exergy efficiencies, cumulative exergy demand (CExD), and associated environmental impacts. The results reveal significant differences between the two methods: open-pit mining is heavily dependent on fossil fuels (53% of input exergy), with 99.62% of total exergy destroyed, resulting in an exergy efficiency of just 0.37% and a sustainability index (SI) of 1.00. In contrast, alluvial mining relies predominantly on water (94%), with 69% of input exergy destroyed, an exergy efficiency of 31%, and an SI of 1.46. Four strategies are proposed to reduce environmental burdens: improving efficiency, minimizing exergy losses, integrating renewable energy, and adopting circular economy principles. This study presents the first application of exergy analysis to comprehensively assess the exergy cost of gold production, from extraction through refining, casting, and molding, highlighting critical exergy hotspots and offering a thermodynamic foundation for optimizing resource use in mineral processing.

Investigation of Strength Diversity Characterization in Mineral Materials Using Discrete Element Method

Accurate modeling of ore materials is fundamental to high-precision simulations in mineral processing and remains a key research focus. To address the modeling challenges arising from the inherent heterogeneity and strength diversity of ores, this study proposes a novel method based on the bonded particle model (BPM) in the Discrete Element Method (DEM), incorporating multi-sized sub-particle stochastic generation and assembly, as well as bond strength parameter design. The method was applied to model and simulate impact crushing of 30 mm size fraction gold, iron, and copper ores with varying strengths. The resulting particle size distributions of fragmented ores were analyzed. Furthermore, drop weight tests were conducted on ore samples of the same size fraction, and the experimental mass distribution of fragmented particles demonstrated good consistency with simulation results. These findings validate the capability of the proposed method to effectively characterize the strength diversity of natural ores, offering an advanced approach for high-fidelity modeling of mineral materials.

Evaluation of Energy Consumption for Mineral Processing of Tungsten Ore in Mongolia: Khovd Aimag and Erdene-Soum as Case Studies

The tungsten deposits in Mongolia have the potential to be exploited as an alternative source to alleviate the risk due to the monopolization in the global production of such a critical metal. However, it is challenging to develop an efficient mineral processing method that can complement the supply based on the currently available energy resources in Mongolia. Therefore, the present study investigated the range of energy required for the beneficiation of tungsten ores, including theoretical assumptions and practical evaluation for two processes in Mongolia. The range of energy consumption was 0.12 to 2.21 kWh/t for crushing and 0.29 to 4.62 kWh/t for grinding regarding the range of Kick’s constant 0.2–0.6 kWh/t and Bond work index 7–17 kWh/t, respectively. The most dominant impact factor in the comminution was the product size. The evaluation of 18 different comminution–flotation circuits indicated a range of required energy from 362 kWh to 8298 kWh. The maximum values of energy consumption for mineral processing of Erdene-soum and Khovd Aimag tungsten ore were 6280 and 6355 kWh. An estimation regarding the energy demand (6355 kWh) and supply energy for the process of Khovd Aimag ore was conducted to propose a suitable system of renewable energy resources using the power pinch analysis method.

Hilirisasi Mineral Pengelolaan Nikel di Indonesia: Regulasi serta Dampak Implementasinya Pada Ekonomi dan Pembangunan Smelter

Nickel is one of the important mining materials in Indonesia due to its significant resources and reserves availability. This paper discusses the downstream management of nickel mining materials by taking regulations, economic impacts and smelter development issue in one frame of discussion. Mining Law 4/2009 amended by Mining Law 3/2020 is the base regulation for downstream mining policy in Indonesia, including for nickel. Obligation of mineral processing and refining domestically and restrictions of nickel exports are two main issues that have multiple impact in nickel management process. The relative increase of annual nickel production is part of the economic impact of downstream policy. Export restrictions affect the fluctuation of nickel production volume and have an impact on economic relations between Indonesia and consumer countries, resulting in a lawsuit by European Union against Indonesian government. On the other hand, the construction of nickel smelters encourages value of nickel exports, absorption of local labor and encourage micro economic activities. It takes time to implement smelter construction in sufficient quantities as mandated in the Regulation. Projections of market absorption capacity, infrastructure such as electricity facilities, technology and capital are mine factors that influence its implementation