Kompleksnoe Ispolzovanie Mineralnogo Syra = Complex use of mineral resources

Technological, economic and environmental aspects of the production of sulfate-resistant Portland cement clinker based on the mineral resources of Karakalpakstan

A.Sh. Khadzhiev — 2026-06-10

This study focuses on the production of sulfate-resistant Portland cement clinker using local raw materials found in the Aral Sea region of the Republic of Uzbekistan and on its properties. The obtained results highlight the technological, economic, and environmental advantages. The raw material mixtures consisted of limestone, barren sand, kaolin, and iron-containing industrial waste, resulting in a clinker with an optimized oxide composition (LSF = 0.82, SR = 2.15, AP = 0.94). X-ray phase analysis reveals a high content of alite (C₃S ≈ 38.6%) and belite (C₂S ≈ 41.0%) phases, which ensures high mechanical strength. Low tricalcium aluminate content (tricalcium aluminate < 5%) and sufficient ferrite content (C₄AF ≈ 16.2%) increased sulfate resistance and phase dominance. Sulfate resistance tests conducted in accordance with ASTM C1012/C1012M showed that sulfate-resistant Portland cement had the lowest swelling index among samples immersed in a 5% Na₂SO₄ solution, demonstrating its superior stability compared to conventional Portland cement and mixed cement types. The experimental results demonstrate the feasibility of producing high-quality sulfate-resistant Portland cement clinker using local raw materials and demonstrate its potential for use in the sulfate-rich conditions of the Aral Sea region. From an economic perspective, the use of local raw materials reduces production costs, the need for imports, and increases the competitiveness of the cement industry in our region. From an environmental perspective, the long service life of sulfate-resistant Portland cement and the ability to utilize industrial waste align with the principles of a "green economy" and promote waste reduction and sustainable growth.

Mathematical modeling and ecological assessment of fluoride release in a mixture of mineralized phosphorite waste and wastewater from the fat and oil industry

Sh.R. Kurambayev — 2026-06-11

This study investigates fluoride loss in a mixture of mineralized mass (MM) extracted from the Central Kyzylkum phosphorite deposits and acidic wastewater (AWW) generated by the fat-and-oil industry. The research aimed to evaluate fluoride release and its retention stability under various conditions. Experimental trials were conducted using AWW:MM mass ratios ranging from 100:10 to 100:40. The experiments were carried out at 333 K for 30 minutes, employing ionometric analysis. The theoretical fluoride content varied from 1.23 g to 4.90 g, while the experimental values ranged from 0.88 g to 3.68 g. The lowest fluoride loss was observed at the 100:20 ratio, amounting to 0.34 g. The highest loss, 1.22 g, was recorded at the 100:40 ratio. The 100:25 ratio (pH 5.90), with a fluoride loss of 0.40 g and an experimental retention of 2.66 g, was identified as optimal. At pH values between 6.33 and 7.30, fluoride levels stabilized between 3.08 g and 3.68 g. An exponential regression model demonstrated a high degree of correlation (R² = 0.9767). The standard deviation ranged from ±0.002 g to ±0.008 g. Ions in AWW (SO₄²⁻: 48,145 mg/L and Cl⁻: 38,116 mg/L) significantly accelerated fluoride volatilization. The emission of HF gas contributed to atmospheric pollution; however, the 100:25 ratio minimized environmental impact. The results aligned with literature-reported fluoride loss ranges of 0.3–1.5 g. This research contributes to the development of effective and environmentally safe approaches to waste reutilization.

Study of the mechanism and efficiency of using mineral-organic bleaching-filtering agents in polishing refining

N.I. Boyjanov — 2026-06-11

In this scientific study, the main objective is to purify vegetable oils stored in the state reserve for an extended period to reach consumable quality based on their physicochemical parameters. In the experiments, polishing refining of cottonseed oils stored for 6 months or longer was carried out. By analyzing the physicochemical parameters of polishing-refined vegetable oils, selective bleaching-filtering agents (BFAs) with various pore structures were obtained for use in the bleaching-filtration stage. The BFAs were obtained through acid activation of bentonitic and opoka-type clays, as well as pyrolysis of sunflower husk. The filtration capacities of each activated BFA toward polishing-refined oils were investigated. The findings show that the highest efficiency was achieved when a composite BFA of the BK grade-prepared at a 1:1 mass ratio of acid-activated Navbahor alkali bentonite (ANAB) and pyrolyzed sunflower husk (P-SH) was added at 1.5-2.0% relative to the oil mass. The research results demonstrate that a composition consisting of polar organic and non-polar inorganic components was successfully obtained, capable of filtering fine soapstock particles while not resisting pressure buildup during the filtration process.

Placer formation processes in the cenozoic of Northern and Eastern Kazakhstan

I.P. Poezzhaev — 2026-06-09

The article is devoted to the generalization of data on the entire geological and genetic range of placers in Eastern and Northern Kazakhstan: from the weathering of the kaolin profile at the root sources of ore minerals Au, Ni, Co, RM, Ti, Zr, Nb, TR, through polyfacial and alluvial placers of the near demolition of the Zaisan depression to coastal-marine titanium-zirconium placers Northern Kazakhstan and Pavlodar Irtysh region. The sections and patterns of ore localization for gold- and nickel-bearing weathering crusts of the Rudny Altai are considered in more detail. An idea is given of the different conditions of formation of the Paleocene-Miocene ilmenite placers of the Zaisan Depression, depending on the tectonic regime – rifting in the Paleocene-Eocene and orogeny in the Lower Miocene. The dating of titanium-zirconium placers of the Pavlodar Irtysh region has been clarified due to the large-scale removal of silicon from the eluvium of the Kazakh shield. The relationship of the processes of coastal-marine placer formation with regional paleogeographic changes in Central Eurasia, starting with the collision of Hindustan and Eurasia and the Paleocene- Lower Eocene temperature maximum, is shown. The role of the completion of water exchange between the Tethys and Arctic shelf seas in the occurrence of constant westerly winds from the Tarim and Gobi, which played a major role in the formation of placers in the northern border of the Kazakh Shield, is shown.

Identification of Methane-Bearing Coal Seams in Borehole Sections of the Karaganda Basin Using Geophysical Logging Data

V.S. Portnov — 2026-06-09

The Karaganda coal basin is one of the most gas-bearing in the world. Its feature is that there are no large accumulations of free gas in it, while the natural gas content reaches up to 25-30 m³/t; this is confirmed by a large volume of gas sampling, gas logging data, and gas survey data in operating mines. Methane from coal seams enters the atmosphere through natural migration through overlying rocks, as well as at the places where seams outcrop under overburden and through the shafts of closed mines. During degassing of coal seams in the Karaganda basin during the opening of seams by mine workings, including during open-pit mining, seam outcrops to the surface, degassing of the worked-out space of closed mines, part of the extracted methane is used at the mines for obtaining thermal and electrical energy, and the larger part enters the atmosphere during degassing of coal seams. It is known that methane entering the atmosphere retains the Earth's heat significantly higher, by 25-30 times, than carbon dioxide. The extraction of methane from unloaded coal seams for its industrial use in obtaining thermal and electrical energy is an important task in the development of technologies for the integrated development of coal-methane deposits, as well as for reducing the environmental load on the regions where they are located. The purpose of the research is the identification in the section of gas-bearing coal seams for assessing the potential of methane extraction from unloaded seams for its industrial use and reducing emissions into the atmosphere. Methods. A complex of geophysical methods for studying exploration wells to investigate the physico-mechanical and filtration-capacity properties of coal seams and host rocks, sampling and analysis of coal seam samples in mine workings. Results. Patterns of changes in the complex of physical properties of coal seams determining their gas content have been established, geological justification for these changes and changes in the physico-mechanical properties of host rocks has been given. Application. The gas-bearing coal seams identified in the section can be used in planning methane extraction from all gas-bearing seams of the geological section, including coal seams being developed by mines, and the patterns of changes in physico-mechanical and filtration-capacity properties of coal seams prepared for development or being developed can be used in geomechanical calculations. The factual materials for conducting the research were obtained from the results of laboratory and geophysical studies of exploration wells, materials from geological and production reports.

Optimization of Aluminum Casting Process Using PLA-Based Casting Patterns and Analysis of their Thermal Behavior

Y.S. Merkibayev — 2026-05-29

This paper presents the results of experimental and numerical studies of the casting process of 99.85% pure aluminum using investment-casting technologies with patterns produced by additive manufacturing. The influence of pouring temperature, mold-filling time, and gating-system design on porosity formation and casting quality was analyzed. It was established that increasing the pouring temperature within the range of 700–800°C leads to increased porosity due to higher gas solubility and intensified turbulence of the melt flow. It was shown that the separating gating system ensures a minimum number of defects compared to top and bottom metal-feeding systems. In addition, thermal analysis of PLA and a glass-fiber-reinforced PLA composite was carried out. Pure PLA was found to burn out almost completely (residue about 2.4%), whereas the composite was characterized by a high residual content (~43.6%), which may negatively affect mold quality. The simulation results obtained using the AutoCAST software package showed good agreement with the experimental data and confirmed the effectiveness of numerical modeling for optimization of casting processes. It was established that the optimal pouring-temperature range for aluminum is 720–760°C. The obtained results confirm the potential of using PLA in investment casting technology and make it possible to improve the quality of aluminum castings under industrial production conditions.

Deep Copper Recovery from Autogenous Smelting Slags under Strongly Reducing Conditions

D.Kh. Altybayeva — 2026-06-01

Deep reduction of copper smelting slags is a promising route to recover entrained non-ferrous metals and to generate slags suitable for further processing. This work investigates the depletion of fayalite–magnetite slags formed during autogenous smelting of copper concentrates in conditions simulating the oxidation and reduction zones of a two-zone Vanyukov furnace. Laboratory charges of 100 g, containing 14.63–16.82 wt.% Cu, 25.6–27.6 wt.% Fe, 30 wt.% S and 15 wt.% SiO₂, were smelted at 1350 °C with controlled oxygen injection to produce slags containing 0.93–1.54 wt.% Cu, 30.05–32.30 wt.% SiO₂ and 7.8–9.8 wt.% Fe₃O₄. Subsequent reduction at 1300 °C was carried out with activated carbon in a fivefold stoichiometric excess relative to magnetite, at an oxygen-containing blast flow rate of 5 L/h and a 1 h holding time. Chemical analysis shows that Fe₃O₄ in slag decreases from 7.8–7.95 wt.% to 2.5–2.6 wt.%, while copper content drops from 0.93–1.033 wt.% to 0.43–0.50 wt.% under oxygen partial pressures of 10⁻¹²–10⁻¹¹ atm. X-ray diffraction and electron microscopic studies reveal a transition from fayalite–magnetite slags with dispersed metallic copper and sulfides to fayalite-dominated matrices containing ferruginous sphalerite, copper minerals of the bornite–chalcopyrite type, iron oxides and glassy phases. Simultaneous thermal analysis demonstrates that all major endothermic and exothermic events are completed by 1300 °C, supporting this as an optimal temperature for deep slag depletion. The results define an operating window—slag composition, temperature, reductant dosage and pO₂—under which copper losses to slag can be reduced to about 0.5 wt.% in industrially relevant fayalite slags.

Influence of gas flow parameters on the velocity of bulk materials

S.S. Аkhmetova — 2026-06-05

This article examines the flow patterns and kinetics of granular media interacting with ascending and descending gas flows. Bulk material release control is a critical aspect of shaft furnace and hopper operation Experimental studies were conducted on a flat transparent model and a close-up "hot" model using high-speed video recording (SK-16). With an error in the calculated values of the critical speed, amounting from to -30.0 to +28.8 , the main parameters varied within the following limits: specific gravity and viscosity of the gas, respectively, from 11.97 to 1.16 N/m³; from ; diameter, specific gravity and coefficient of internal friction of bulk material from m; from kN/m³; from ; coefficient taking into account the shape of the particles, from ; outlet diameter from m; attitude equals . The materials studied were agglomerate, lime, millet, and coke; the gas phases were air, helium, and hydrogen. It was established that the outflow mechanism is staged and determined by the frequency of destruction of dynamically unstable vaults. It was found that gas density is the key factor influencing the outflow rate, while the effect of viscosity is secondary. An analytical relationship was formulated for calculating the critical gas velocity that causes layer suspension. The obtained data make it possible to optimize the design parameters of outlet openings and blast supply modes in metallurgical units.

Elemental Assessment of Lead–Bismuth Sludge from Copper Smelting with Emphasis on Tellurium Recovery

M. Tulaganova — 2026-06-09

Industrial by-products generated during copper smelting are increasingly regarded as promising secondary sources of strategically important and critical elements. Among such technogenic materials, lead–bismuth sludge formed during wet gas cleaning of sulfur-bearing gases represents a potentially valuable reservoir of selenium and tellurium. The present study provides a comprehensive elemental assessment of lead–bismuth sludge obtained from the Almalyk Mining and Metallurgical Complex (Uzbekistan). Prior to analysis, representative sludge samples were subjected to acid digestion using freshly prepared aqua regia, followed by elemental determination using inductively coupled plasma optical emission spectroscopy (ICP-OES). Particular attention was devoted to the distribution behavior of selenium and tellurium due to their technological importance as critical raw materials. The analytical results demonstrated that the investigated sludge is characterized by a pronounced polymetallic composition dominated by lead (20.0%), together with significant concentrations of iron (6.76%), copper (5.34%), and zinc (4.40%). Tellurium was detected at a concentration of 0.33%, indicating its selective accumulation in the lead–bismuth residue, whereas selenium was not detected under the selected analytical conditions. Based on elemental composition data and thermodynamic considerations, the investigated sludge may be considered a promising secondary source for tellurium recovery. The obtained results contribute to understanding the physicochemical behavior of chalcogen elements during copper smelting and wet gas-cleaning processes and may serve as a basis for the development of integrated recycling approaches for technogenic metallurgical waste.