Large-scale metal mining operations extract vast quantities of ore and waste rock annually, generating both economic benefits and significant environmental challenges. While mining supports industrial growth, technological advancement, and job creation, it also imposes substantial social and ecological costs, particularly from the disposal of waste rock. These mine wastes increase the burden of handling, dumping, reclamation, and long-term monitoring, often undermining sustainability objectives. Reducing waste generation within ultimate pit limit design is therefore essential to align mining with sustainable development policies. This study develops a novel framework that integrates mathematical modeling with Q-learning, a reinforcement learning algorithm, to optimize ultimate pit limit by maximizing ore recovery and profitability while minimizing waste rock extraction. A key innovation of the model is the explicit inclusion of environmental costs, covering prevention, mitigation, and compensation of impacts, as a fundamental component of block economic value. The approach is validated using a large scale copper ore deposit, and compared against the widely used Lerchs-Grossmann algorithm. Results show that the Q-learning framework reduces waste rock extraction by 2.7 million tons, with about 0.5 million tons less ore recovered, while also lowering computational time from 7.2 to 5.8h. Although Lerchs-Grossmann yields slightly higher profit, it ignores environmental costs, leading to less sustainable outcomes. Overall, the framework prioritizes realistic pit design over superior economic gains. By embedding environmental factors into mine planning, it enhances resource efficiency, minimizes ecological impacts, and promotes cleaner production, thereby advancing sustainability in mining through reinforcement learning-based optimization.

Abstract Screening units, which are essential machines across industries where improvement studies are needed today, have gained importance efficiency and energy saving. In this study, the screening process of the copper ore pile was analysed using the discrete element method (DEM) employing the geometry and feeding conditions of the mobile screening unit. Using initialanalyses, the effects of screen rotation speed and pile volume for different mass distributions are evaluated to identify the most effective configuration. The effect of hole geometry and mass distribution was examined by modifying the size distribution of the pile. Efficiency and capacity calculations were performed by increasing the pile’s feeding volume with equal mass distribution. In this study, which aims to identify the conditions under which the most efficient and highest-capacity screening operation occurs, improvements were made to the screen design. In addition, the wear analysis was simulated, and the effect of changes in feeding conditions on the screen life was investigated. The results highlighted that the screen design to be used in the screening operation is directly affected by the pile characteristics, demonstrating the significance of DEM-based modelling in industrial screening optimization. Graphical Abstract

This study evaluates sensor-based pre-concentration using XRT technology as an alternative to selective mining for low-grade European copper ores (0.48% Cu), addressing the need for sustainable beneficiation amid declining ore grades and environmental pressures in green mining initiatives. Copper ore samples from Złote Hory mine (Czech Republic) were selectively extracted, mixed (1:1:1 ore 8–16 mm/ore 16–32 mm/waste rock 8–32 mm), and analyzed on Comex’s LSX-MAX laboratory sorter with dual-energy XRT sensors, calibrated for maximum product recovery via density-based classification into High-Density (product) and Low-Density (waste) fractions. Sorting achieved a 1:1 product-to-waste mass split from feed (Cu = 0.5%, 100% mass), yielding pre-concentrate at 0.91% Cu (52.08% mass yield, 95.67% recovery) and waste at 0.04% Cu (47.92% mass, 4.33% loss)—a 1.82x grade upgrade superior to mixed feed and 1.42x superior to selective mining (0.64% Cu at 66.21% yield). Combined approaches promise further optimization; future work will assess downstream grinding/flotation impacts, industrial scaling, and economic/environmental benefits.

Harnessing hydrogen mineral phase transformation for high-efficiency iron and copper extraction from complex iron oxide copper ores

Spray-drying-granulated composite oxygen carrier using fine copper ore and hematite powders as raw materials

Rapid elemental imaging of copper-bearing critical ores using laser-induced breakdown spectroscopy coupled with PCA and PLS-DA.

The flotation of unevenly disseminated minerals presents a persistent challenge in mineral processing. In this study, a combined flash flotation and split flotation approach was developed based on mineralogical analyses aimed at enhancing the recovery of unevenly disseminated copper sulfide minerals. Mineralogical analysis indicated that, under a feed particle size of P80 at 200 μm, 31.65% of copper sulfide minerals were fully liberated, with 28.40% falling within the 20-147 μm size range, which is optimal for flash flotation. The flash flotation yielded a concentrate grading 54.96% Cu at a Cu recovery of 31.03%. This, together with a subsequent process incorporating split flotation, has led to a final concentrate grading 48.85% Cu and with an overall Cu recovery of 95.67% being obtained. The recovery represents about 6.5% improvement when compared to the conventional flotation process that is currently employed on site. The improvement is also accompanied with a reduction in collector and frother consumptions of 23% and 28%, respectively. The results demonstrate the effectiveness of the combined process incorporating flash flotation and split flotation for handling unevenly disseminated Cu ores dominated by chalcocite.

ABSTRACT This study explores the use of ozone (O3) as an oxidizing agent to enhance the selective flotation of copper (Cu) and arsenic (As) sulfide minerals. Bench-scale flotation experiments were conducted on arsenic-rich copper ores at pH 3,7, and 12, using three gas regimes: air, pure O3, and O3–air mixture. The optimal separation was achieved under acidic conditions (pH 3) with pure ozone, obtaining a Cu recovery of 92.2% and a concentrate grade of 16,245 ppm, while reducing As recovery to 17.9% and its content in the concentrate to 76 ppm. X-ray diffraction analysis confirmed the oxidation of enargite (Cu3AsS4) into scorodite (FeAsO4), indicating arsenic transformation from the more soluble and toxic As(III) to the stable As(V) form. Flotation kinetics showed that the best Cu-grade (21,308 ppm) was achieved within the first 3 minutes, after which the grade declined and As content increased. These results demonstrate that O3 flotation promotes arsenic partitioning into tailings while maintaining high copper recovery in the concentrate. The formation of scorodite enhances the environmental stability of arsenic residues. Therefore, ozone-assisted flotation under acidic conditions offers a promising and sustainable alternative for the processing of complex Cu – As ores, reducing the risk of arsenic volatilization in downstream operations.

The article is based on material collected during the PhD project on hydrothermal mineralisation in the Polish Tatra Mountains, linked to historic copper and silver mining. The study focuses on the Polish part of the Western Tatras, where numerous signs of past mining activities have been identified, described, and documented. Five preserved features, four adits, and a large heap with a collapsed shaft crater were discovered. Mineralogical and geochemical analyses indicated that the primary components of the ore veins are tetrahedrite-( Zn) and tetrahedrite-(Fe), occurring as intergrowths with chalcopyrite, and less frequently with pyrite and galena. Fluid inclusion studies showed low homogenisation temperatures and low salinity of the mineralising fluids. Eutectic temperature measurements demonstrate that the inclusions represent H₂O–NaCl solutions with a minor KCl component. The sequence of hydrothermal mineral formation in the Western Tatras is reconstructed as: carbonates I → quartz I → barite I → quartz II + carbonates II + ore minerals + barite II → supergene mineralisation. The mineralisation in the Polish Tatra Mountains is classified as dolomite/siderite–quartz type with tetrahedrite. Additionally, evidence for a quartz–carbonate stage with copper sulphides was documented.

The study estimates net migration flows between rural and urban areas in Zambia between 1951 and 2022. An innovative method is proposed, based on an estimation of differences in net fertility between urban and rural. Data come from two sources: population censuses which provide proportions urban and population growth rates at regular intervals, and demographic and health surveys (DHS) which provide trends in fertility, child survival and net fertility. Results show huge net migration flows between rural and urban areas, at times positive (1951-1980) and (2000-2022), but negative at other times (1980-2000). Net migration contributed positively to 54% of urban growth in the first period, and 44% in the third period, but negatively in the second period (−28%). These fluctuations were correlated with changes in economic growth, positive between 1950 and 1975 and between 1995 and 2020, but negative between 1975 and 1995, mainly because of increasing or decreasing prices of copper ore on international markets. Counter-urbanization was concentrated in the mining cities of the Copperbelt. Zambia appears as an outstanding case of the impact of economic fluctuations due to an external shock on urbanization. However, over a long period (1951-2022), urbanization in Zambia was similar to the average in sub-Saharan Africa.

Did ore diversity reflect selection beyond colour? a multi-analytical insight into early copper ore procurement at Gre Fılla

This paper presents the recovery of copper from a Nigerian low-grade copper ore containing 4.08 wt. % Cu via nitric acid leaching, followed by solvent extraction using soybeans oil fatty acid extractant. The leaching tests on the milled ore were done according to a 3-factor Central Composite Design with time, acid concentration and temperature as the selected process variables. Regression models were developed from the experimental data for the ore dissolution and the quantity of copper extracted, and the effects of the individual process variables and their interactions were determined from the leaching studies using analysis of variance (ANOVA). Results from the leaching tests indicate that the ore dissolution depends mainly on the leaching time. About 92 percent of the copper contents were recovered at optimum leaching time, temperature and nitric acid concentration of 29.5 min, 81.25 oC and 2.18 M, respectively. The solvent extraction studies show that copper can be extracted from aqueous media using soybeans fatty acid, with the performance of the diluents in terms of the quantity of Cu extracted being MIBK > kerosene > xylene.

Electrochemical activation of pulp as a method for increasing the efficiency of beneficiation of oxidized copper ores

The selective separation of copper sulfide ore from iron sulfide minerals has always been a technical problem that urgently needs to be solved. This study conducted a process mineralogy research on a copper–tin polymetallic ore in Yunnan. The research results showed that the ore sample contained 0.33% copper, and the oxidation rate of copper was 16.48%. The distribution rate of copper in its independent minerals was only 58.30%. The copper content in oxidized copper and hematite/limonite was relatively high, making it difficult to achieve a high flotation recovery rate. The priority flotation process was applied to the flotation process of this copper mine. The final copper flotation scheme determined was that the grinding fineness of −0.074 mm was 55%, “two roughing, one scavenging, and three cleaning”. This was followed by the re-grinding of the coarse concentrate, with the collector being ML-8:Z-200 = 2:1, the dosage being 60 g/t, and calcium hypochlorite as the copper–sulfur separation inhibitor. Finally, a copper concentrate product with a copper grade of 16.83% and a recovery rate of 54.31% was obtained. At this time, the silver grade was 388.55 g/t, achieving efficient recovery of the copper ore. The comprehensive utilization of multi-metallic copper sulfide in the processing plant has high practical significance.

Bronze age casting cakes from the Domažlice region compared with the Mutěnín copper ore deposit in Western Bohemia (Central Europe)

In this study, bioleaching experiments on Kastamonu Hanönü copper ore were conducted using the bacterium Acidithiobacillus ferrooxidans in the presence of seawater. The characterization of the sample was performed using XRD, XRF, and SEM analysis methods. During the bioleaching experiments, bacteria concentration, pH, copper and iron concentrations were monitored over the 360-hour test period. The results demonstrated that an appropriate proportion of seawater significantly promoted copper recovery, with the solid-to-liquid ratio playing a key role. A maximum copper recovery of 81.43% was achieved in the presence of 30.00% seawater, 7% solid rate compared to only 71.02% in its absence. This study highlights the potential of seawater as an alternative solvent medium, offering both environmental and economic benefits. Moreover, the findings emphasize the applicability of the bioleaching method as an environmentally friendly and efficient process.

The paper discusses the practical experience in formation and operation of a tailings storage facility in conditions of a high-performance mining and processing plant. The main technical solutions are presented for formation of the tailings dam and managing of the tailings overflow along the perimeter of the tailings dump. A scheme is described and plans are presented for the development of the tailings facilities at the Mikheyevsky Mining and Processing Plant. Physical and mechanical properties of the porphyry copper ores tailings from the Mikheyevskoe deposit have been studied. Disadvantages of the classical approaches to designing tailings dumps for disposal of the waste of processing porphyry copper ores are specified. Geotechnological solutions are justified for upgrading the tailing dump to increase the efficiency of clarifying the recycling water. Technical solutions are proposed for formation of additional structural elements within the water area of the tailing dump. Requirements are formulated for designing of the tailings dams to accommodate tailings of porphyry copper ore processing.

The origins of copper ores at Gre Fiılla (TÜRKİYE): Lead isotopic evidence for multi-source procurement

Chloride leaching of copper ores: influence of NaCl on gangue dissolution and its effect on copper leaching kinetics

Microwave-enhanced heap leaching of porphyry copper ores: Part 1 – The role of mineralogy in microwave-induced fracture networking measured by X-ray computed tomography