In this paper, the microstructural, chemical, and phase evolution of a Ti-6Al-4V alloy fabricated by Laser Powder Bed Fusion (LPBF) and subsequently subjected to electron irradiation was investigated. The LPBF process results in the formation of a nonequilibrium microstructure under rapid solidification conditions (≈10⁵–10⁶ K/s), including acicular α′-martensite, oriented prior β grains, and microporosity (≈0.2–1.0 μm). Scanning electron microscopy (SEM), energy-dispersive spectroscopy (EDS), and X-ray diffraction (XRD) were employed to characterize the material before and after irradiation. SEM observations revealed that electron irradiation increased the agglomerate size from approximately 50–100 μm to 70–150 μm, while reducing pore size from 0.2–1.0 μm to 0.05–0.6 μm. EDS analysis indicated a decrease in Ti content accompanied by an increase in oxygen and carbon concentrations, suggesting surface oxidation and chemical modification. XRD analysis confirmed the transformation of the initial Al–Ti intermetallic phases and the predominance of the hexagonal Ti phase after irradiation. Changes in lattice parameters (a: 2.927→2.936 Å; c: 4.663→4.676 Å) indicate lattice expansion and redistribution of internal stresses. The obtained results demonstrate that electron irradiation significantly affects the structural state of LPBF-fabricated Ti-6Al-4V alloy and can be considered an effective approach for tailoring the process–structure–property relationship in additively manufactured titanium alloys.
The determination of deformation resistance was conducted using a DIL805A/D quenching dilatometer equipped with a hydraulic unit, enabling compression tests during high-temperature forming at specified strain rates. Deformation resistance was experimentally defined for a 5x5 testing matrix, covering deformation temperatures (800, 900, 1000, 1100, and 1200 °C) and strain rates (0.001, 0.01, 0.1, 1, and 10 s⁻¹). Boron-alloyed steel, also known as BCT steel, was used as the experimental material. The Garofalo equation was employed to evaluate the experimental measurements of deformation resistance. This equation describes the hot metal forming process, where deformation resistance is a function of strain rate and temperature. The material constants of the Garofalo equation were determined based on peak stress values obtained from individual deformation curves. The technological process of metal forming is defined by three parameters: strain rate, deformation temperature, and strain level. The Garofalo equation does not include the last parameter, strain level, as an independent variable. Therefore, the Garofalo equation was modified into a strain-dependent model by transforming the material constants into functions of strain. Each material constant was expressed as an n-th degree strain polynomial. In this manner, the third independent variable, strain level, was introduced into the Garofalo equation. To improve the correlation between measured and calculated data, the degree of the strain polynomials was increased. Some publications have utilised strain polynomials up to the 14th degree; however, such a model requires up to 60 material constants. This paper presents the transformation of the Garofalo equation into an energy-based model. The core of this transformation lies in expressing the activation energy constant as a function of strain rate, temperature, and strain level. The material constants Alpha, n, and C remain unchanged, retaining their original meaning as defined by Garofalo. The activation energy is defined by 14 material constants. Together with the remaining three constants, a total of 17 material constants sufficiently define the incorporation of the strain level into the Garofalo equation. A 3D visualisation of the energy model of the Garofalo equation showed that this equation has an extremum, a global maximum of deformation resistance.
The paper presents the results of a study of the physicochemical and mineralogical properties of primary and secondary aluminum slags. It was found that the primary aluminum slags contain 67.8% Al2O3, 12.4% SiO2, 4.58% MgO, 4.59% CaO, and 0.52% Fe2O3. The main phases are spinel (25.4%), sapphirine (26.0%), corundum (25.0%), enstatite (11.9%), and mullite (11.7%). These high-temperature aluminosilicate and oxide phases have high thermodynamic stability and low chemical activity, which significantly complicates the processing of primary slags. The secondary aluminum slags contain 34.9% Al2O3, 4.61% SiO2, 34.7% CaO, 5.70% MgO, and 4.71% Fe2O3. The mineral composition is represented by spinel (20.5%), quartz (10.5%), mullite (8.0%), corundum (13.1%), calcite (27.0%), and breyite (20.9%). Complex aluminosilicate compounds were not detected in the secondary slags, which determines their higher reactivity. The potential of using secondary aluminum slags in metallurgical processing is demonstrated, in particular in the production of ferrosilicon in the form of pellets with the addition of ferrosilicon metal fines, which allows for a reduction in the consumption of natural silica materials and an increase in the resource efficiency of production. The obtained results can be used in the development of energy- and resource-saving technologies for processing aluminum waste.
The growing demand for molybdenum and the involvement of low-grade and man-made raw materials in the processing necessitate the development of effective hydrometallurgical methods for its extraction from complex solutions. In this work, the sorption behavior of molybdenum from sulfuric acid solutions was studied using a weakly basic anionite Purolite A-100. Sorption experiments were performed under static conditions at a temperature of 25 оC with a variation in the initial concentration of molybdenum, and the equilibrium data were analyzed using Langmuir, Freundlich, and Dubinin–Radushkevich models to evaluate the nature of the interaction and describe the sorption process. It is shown that the equilibrium is most adequately described by the Langmuir model (R2 = 0.9868), which indicates the predominantly monolayer nature of sorption. The calculated value of the average sorption energy (E ≈ 6.28 kJ/mol) indicates that the sorption process occurs predominantly through weak physicochemical interactions with a contribution of ion-exchange mechanisms. With an increase in the concentration of molybdenum, a decrease in the degree of extraction is observed, associated with saturation of the active centers of the sorbent, while the formation of sulfate forms of molybdenum and competition of sulfate ions in a sulfuric acid medium have a significant effect. The results obtained characterize the equilibrium behavior of molybdenum in sulfuric acid solutions and can be used in the development and optimization of ion exchange technologies for its extraction from acidic media.
The article presents information on raw material resources and iron ore production worldwide. Kazakhstan is among the world's top ten iron ore-producing states. As high-grade iron reserves become exhausted, ores with low iron content and high impurity levels, including sulfur, are increasingly being processed. Various methods of iron ore desulfurization are discussed: flotation, magnetic, and combined approaches based on pyro- or hydrometallurgical processes that alter the chemical composition of the feedstock. The review provides information on methods for beneficiating low-grade iron ore and their significance for the development of iron and steel metallurgical production.
This study presents the results of investigating the effect of reverse carbon flotation on gold recovery from secondary technogenic raw materials—aged sorption tailings with a high carbon content and refractory forms of gold. Direct cyanidation of the initial material showed low efficiency (up to 13% gold recovery) due to the pronounced preg-robbing effect. Comparative flotation tests demonstrated that the highest gold losses occurred during conventional sulfide flotation using xanthate. Additional grinding of the material increased gold extraction during cyanidation but was accompanied by higher losses during flotation. The application of reverse carbon flotation with kerosene and frother effectively removed the carbonaceous fraction and reduced gold adsorption from the solution. Further oxidation with trichloroisocyanuric acid enhanced the gold recovery up to 78.25%. Biological oxidation using Acidithiobacillus ferrooxidans also increased the gold recovery from both the initial material and the products of reverse flotation.
This study investigated the formation of non-metallic inclusions and their characterization during the melting of AISI1066 steel from secondary metal scrap in an electric arc furnace. The analyses were carried out using scanning electron microscopy (SEM) and energy-dispersive X-ray spectroscopy (EDS). In addition, a deep learning-based segmentation method was applied to improve the identification of inclusions. The results confirmed a heterogeneous microstructure consisting of non-metallic inclusions dispersed within a Fe-based matrix. The size of the inclusions ranged from a few micrometers up to approximately 40 µm. The majority of inclusions were found within the range of 10–25 µm. SEM analysis showed that the inclusions predominantly exhibit irregular and globular morphologies. EDS results confirmed that they consist of manganese sulfides (MnS), oxides (Al₂O₃ and SiO₂), and complex multi-phase particles. The elevated sulfur (S) (0.12 wt.%) and copper (Cu) (0.81 wt.%) contents in the investigated samples indicate that deoxidation and modification processes were not sufficiently effective. The deep learning-based model made it possible to accurately separate non-metallic inclusions in the alloy composition. According to the model results, inclusions larger than ≥30 µm mainly represent the fraction of oxide phases, while fine inclusions smaller than <20 µm represent the fraction of sulfide phases.
This study addresses the desorption of molybdenum from the Purolite A-100 macroporous weak-base anion-exchange resin using ammonium hydroxide solutions, followed by the recovery of technical-grade molybdenum trioxide from the concentrated eluate. Sorption from a model sulphuric acid solution (0.396–0.408 g/L Mo) was carried out at 80°C for 30 minutes, achieving a recovery of 48.7% with a static exchange capacity of 15.8–16 mg/mL. Under standard single-stage saturation, the degree of desorption with 12% NH₄OH did not exceed 27.2%, regardless of contact time (15–240 min) or temperature (20–40°C). A multi-cycle saturation strategy – 25 consecutive sorption cycles – produced a linear increase in resin capacity up to 182.27 mg/mL and brought subsequent molybdenum recovery into the eluate to 94%, at a final concentration of 3.63 g/L (120 g/L NH₄OH, 40°C, 120 min). Thermodynamic modelling of the Mo-H₂O system in HSC Chemistry 8.0 confirmed that pH 1.5 falls within the stability field of MoO₃·H₂O, justifying the chosen precipitation conditions. Acidification of the eluate to pH 1.5 with co-precipitation using ammonium sulphate, followed by calcination at 600°C, yielded 6.21 g of technical-grade molybdenum trioxide identified by XRD as molybdite MoO₃ (PDF 00-035-0609, 100%) with total impurity content below 0.14%.
Gallium (Ga) occurrence in coal is interpreted only by coupling bulk partitioning with microscale residence. Ga distribution reflects allocation between inorganic matter and organics and links to ash yield. Al-bearing aluminosilicates dominate as hosts, with Ga retained mainly by isomorphic substitution governed by crystal chemistry rather than adsorption. Workflows compare where Ga sits versus how it is bound: density fractionation and sequential/selective leaching, constrained by XRD and supported by BSE–EDS, EMPA, and LA–ICP–MS. During combustion, Ga concentrates in fly ash/slag; recovery relies on pretreatment, acid leaching, and sorption/stripping, with calcination/roasting disrupting refractory frameworks, boosting extraction, and controlling impurity co-dissolution.
The pristine o-LiMnO2 (PL) and in-situ composite samples between o-LiMnO2 and graphene nanoplatelets (GNPs) (L-xGNP with x = 1, 3, 5, 7, 9 wt.% of GNPs) were synthesized successfully via a one-step hydrothermal process. The characterization and electrochemical measurement of the obtained samples were performed. The introduction of GNPs in the L-xGNP composites reduces the growth of primary particles of o-LiMnO2 and provides improved performances as cathode in lithium-ion batteries compared to the PL sample, in which the L-3GNP (3 wt.% GNPs) is the optimal sample amongst the L-xGNP composites with the highest discharge capacities of 151.90 mAhg-1 at 0.1 C and 98.46 mAhg-1 at 1 C and remained over 94 % of the discharge capacity after 90 cycles. It also exhibited the lowest charge-transfer resistance (72.007 Ω) and the highest electrical conductivity (4.95 × 10⁻⁵ S·cm⁻¹). The enhanced performance is attributed to improved Li⁺ storage capability, reduced electrode volume variation, and suppressed Mn³⁺ dissolution.
The depletion of rich copper raw material reserves makes the processing of low-grade oxidized and mixed ores from Kazakhstan using SX - EW hydrometallurgical technology particularly relevant. The object of the study was low-grade mixed copper ore from one of the deposits in the Karaganda region, characterized by a high sulfide copper content. The article presents the results of physicochemical studies of the initial ore, its leaching with sulfuric acid at different concentrations, and investigations of copper extraction and stripping processes. The application of modern LIX-type oxime extractants was analyzed. Model solutions were used to study the characteristics of the extraction process that ensure high copper recovery and the subsequent production of strip liquors suitable for electrolytic metal recovery. The study established the effect of pH and extractant concentration on the degree of copper extraction, demonstrated the possible formation of copper complexes with the extractant, and determined their composition. An extractant was selected to study the recovery of copper from pregnant solutions. The data obtained confirmed the efficiency of the SX-EW hydrometallurgical technology for processing substandard mixed copper-bearing ore with high sulfide copper content.
This paper examines the development and future prospects of research and development (R&D) intensity in the Slovak Republic, compared with the EU27 average, in the context of the Europe 2020 framework and the 2030 Agenda targets. R&D intensity, expressed as a percentage of GDP, is analyzed as a key determinant of innovation performance and industrial competitiveness. The study is based on a comparative statistical analysis of Eurostat data covering the period 2010-2024 and on econometric forecasting using the Ordinary Least Squares (OLS) method. Linear regression models were constructed to estimate average annual growth rates and project R&D intensity through 2030. The results reveal a persistent structural gap between Slovakia and the EU average. While the EU27 exhibits an average annual increase of 0.038 percentage points, Slovakia records only 0.024 percentage points. Under the current linear trend, R&D intensity is projected to reach 2.44% of GDP in the EU and 1.14% in Slovakia by 2030, indicating that neither the European 3% target nor the Slovak national target of 2% is likely to be achieved. A paired t-test further confirms the existence of a statistically significant innovation gap. The findings highlight the need for stronger private-sector participation and more effective allocation of public resources, particularly in applied research and advanced materials development, as essential preconditions for enhancing technological upgrading and long-term competitiveness.
For the experiments to determine deformation resistance under heat, a steel with the addition of boron, officially designated as BCT steel, was used. This designation characterizes steel that does not belong to the standardized steel brands. Determining the deformation resistance was carried out using a hardening dilatometer DIL805A/D, which is supplemented with a hydraulic unit. This enables compression tests during high-temperature forming. The deformation mode allows the material to be formed under defined conditions. Such conditions are strain value, strain temperature and strain rate. The deformation resistance for the test matrix 5x5, deformation temperatures (800, 900, 1000, 1100, 1200 °C) and deformation rates (0.001, 0.01, 0.1, 1, 10 s-1) were experimentally determined. A mathematical model was used to evaluate the measured data, which describes the deformation curve depending on the deformation. Furthermore, equations were used to calculate the basic deformation resistance depending on two variables: degree of deformation and temperature of deformation, while the rate of deformation was constant. Appropriate mathematical equations and their graphical visualization are given for the five deformation rates. The Garofalo equation is used to calculate the activation energy of plastic deformation under heat. This equation is further extended by the deformation variable. Based on the results of the physical simulation of the compression process, a mathematical simulation of the compression process was performed. From the deformation curves, after the mathematical simulation of the compression process, it was possible to calculate the activation energy of plastic deformation for different temperatures. Subsequent visualization of the activation energy values showed its dependence on the deformation temperature. The mathematical description showed that the activation energy of plastic deformation is dependent on the deformation temperature, which proves that it is not a constant value as has been published so far.
This review examines technological and resource factors governing zinc production route selection. The mineralogical form of zinc is identified as the primary flowsheet design criterion: sulfide ores require oxidative pretreatment, whereas non-sulfide ores undergo acid leaching but risk silica gelation. Pyrometallurgical and hydrometallurgical pathways are compared regarding metal purity, energy intensity, and residue management. Modern intensification methods – microwave pretreatment, ultrasonic cavitation, and surfactant-assisted autoclave leaching – are evaluated as tools targeting distinct rate-limiting stages: matrix liberation, boundary-layer mass transfer, surface passivation. Cross-referencing with recent advances in copper bioleaching and gold microflotation confirms the universal nature of underlying physicochemical barriers.
The Kosice Summit of Innovation and Technology (KSIT 2025) was held in Bešeňová, Slovakia, from 13 to 15 October 2025. The summit continued to develop its role as an international platform linking research, innovation, technology transfer and industrial practice under the leading topic Fellexcel. The KSIT 2025 conference focused on the content of the scientific contributions presented. The program covered laser powder bed fusion of stainless steels, parameter-sensitive metal additive manufacturing, simulation-assisted prediction of distortions and defects, sheet cutting, asymmetric and cryogenic rolling, lightweight design, mechanical and hybrid joining, and AI-supported communication training. Particular attention was paid to the role of Simufact Additive in reducing trial and error in metal additive manufacturing, and to the relationships among processing parameters, powder characteristics, microstructure, dimensional accuracy, and joint performance. This short communication summarizes the main scientific messages from KSIT 2025 and situates them within the broader context of advanced manufacturing and sustainable industrial development.
The present study investigates the thermodynamic and technological parameters governing the direct-to-blister smelting of copper sulfide concentrates in a dual-zone Vanyukov furnace (PV furnace). Industrial slag and matte samples obtained from the Balkhash Copper Smelter (Kazakhmys Smelting LLP) were analysed using synchronous thermal analysis (STA 449 F3 Jupiter) to determine complete melting temperatures. Laboratory-scale smelting experiments were conducted to determine the compositions of blister copper and smelting-zone slags under controlled oxygen-blowing conditions. Process balance calculations were performed using dedicated software (PV-BALH) to quantify the effects of burden moisture, oxygen enrichment, specific oxygen consumption, and reductant loading on melt temperature, off-gas composition, and product quality. The complete melting temperatures of PV furnace slag and converter slag were determined to be 1172.1 °C and 1195.2 °C, respectively, confirming that the operative process temperature of 1300 °C provides an adequate superheat margin. Laboratory direct-smelting trials produced blister copper containing 94.2–96.3 wt.%. Cu at a process temperature of 1300 °C. The specific oxygen consumption required to transition from matte smelting (220 Nm³/t burden) to direct-to-blister operation (470 Nm³/t burden) was quantified. The optimal burden composition was established as: Cu ≥ 15 wt.%, S ≥ 30 wt.%, SiO₂ ≈ 15 wt.%, moisture ≤ 6 wt.%. The target slag composition after reduction-zone treatment should contain 28–32 wt.% SiO₂, Fe₃O₄ ≤ 8 wt.%, and Cu ≤ 0.7 wt.%. These findings provide, for the first time, a coherent dataset for the Vanyukov furnace operating in direct-to-blister mode, as no industrial plant currently uses this configuration.
The growth dynamics of global steel production indicate market saturation. The slowdown in steel production growth is offset by improvements in steel quality and reduced product consumption. Further improvement in steel quality is not about correcting the composition, but about increasing purity and improving the structure. An increase in operational properties is possible provided that harmful impurities (oxygen, hydrogen, sulfur, phosphorus, non-ferrous metals, etc.) are effectively removed from the metal, and the remaining emissions are controlled to reduce their negative impact on the quality of metal products. And this is impossible without the development and industrial implementation of innovative materials and high technologies aimed at improving the quality and competitiveness of steel and alloys for foundry production, achieving the highest productivity values, reducing production costs, implementing energy-and resource-saving and environmentally friendly technologies, and significantly exceeding the efficiency of existing traditional materials with significantly lower consumption. Modern foreign studies and publications highlight several advanced methods for producing alloy castings in foundries. Special attention is paid to gasified model casting (LGM), which enables the production of high-strength products with precise geometry and improved surface finish. For example, in Fisher et al. (2024), modern non-destructive testing methods are discussed and effectively used to assess the quality of castings produced by these methods.
The growing demand for strategically important metals, coupled with the depletion of high-quality ores, has highlighted the potential of man-made waste as a secondary source of vanadium and molybdenum. This study investigates the alkaline leaching of technogenic vanadium-containing waste (filter cake) using sodium hydroxide (NaOH) and sodium hypochlorite (NaOCl) as an oxidiser. Chemical and X-ray fluorescence analyses confirmed significant contents of vanadium (3.44%), molybdenum (0.75%), and other valuable metals, indicating the feasibility of complex metal recovery. An experimental design based on the response surface methodology (RSM) and a central composite plan was employed to evaluate the effects of leaching time, reagent concentration, pH, and temperature on metal extraction. Quadratic regression models were constructed and validated using analysis of variance (ANOVA), demonstrating high adequacy (vanadium: F = 9.55, p < 0.001; molybdenum: F = 9.84, p < 0.01). Under the identified optimal conditions, vanadium and molybdenum extraction efficiencies reached 88-89% and 80-82%, respectively, and further increased to 89-93% and 82-83%, respectively, following the addition of NaOCl. X-ray phase analysis revealed the formation of stable aluminium and nickel oxide phases, which partially limited extraction and explained deviations from predicted values. The results demonstrate that combining alkaline leaching with an oxidiser and statistical modelling enables effective optimisation of multicomponent waste processing, enhancing metal recovery and reducing environmental impacts, thereby providing a basis for resource-efficient, environmentally friendly metallurgical technologies in Kazakhstan.
Bimetals are composite materials created by combining two different metals with metallurgical bonding at their interface. Squeeze casting is a promising method for bimetal manufacturing; however, the optimal pressure required to achieve desirable mechanical properties remains under investigation. This study aims to determine the casting pressure required to achieve an optimal interdiffusion bond at the aluminium-copper interface. In this work, aluminum and copper alloys were used, with aluminum melted at 750 degrees C and copper at 1150 degrees C. The process involved sequentially pouring molten metals into the mould. Copper was poured first, and once partial solidification occurred, aluminum was subsequently poured, forming an Al-Cu bimetal bushing. Pressure was applied during the first frozen-layer stage at 60, 70, 80, and 90 MPa. Results revealed that applying greater pressure promotes the development of a thicker interdiffusion layer. The interface region exhibited the highest hardness and wear resistance due to the in-situ formation of Al2Cu and Al4Cu9 compounds. Therefore, Al-Cu bimetal can be effectively produced by squeeze casting at 90 MPa, resulting in an optimal interdiffusion zone at the interface.
Wastewater containing cyanide, produced during gold extraction operations, poses a significant environmental threat and requires detoxification procedures that comply with rigorous regulatory standards, including those set by the International Cyanide Management Code (ICMI). Sodium percarbonate was evaluated as an oxidizing agent for the treatment of hydrometallurgical tailings contaminated with cyanide, which is formed at the Altyntau Kokshetau enterprise in Kazakhstan. The operating conditions were optimized using the response surface methodology based on the central composite design (CCD). In experiments carried out at room temperature, pH, oxidizer dose and reaction time were identified as the main factors. The composition of the waste and the transformation of cyanide were monitored using ICP-OES, FTIR spectroscopy, and spectrophotometric quantification of residual cyanide. Treatment with sodium percarbonate reduced the cyanide concentration to below the ICMI limit of 0.2 mg/L and obeyed the biphasic pseudo-first-order kinetics. Of the parameters investigated, pH exhibited the most pronounced influence; it further modulates radical stability and governs the equilibrium between HCN and CN-. The aggregate findings demonstrate that sodium percarbonate constitutes a scalable, environmentally benign alternative to conventional methods for cyanide detoxification in gold-mining effluents.
