Aiman Nygmetovna Kopobayeva

Purpose. This study investigates the geochemical distribution of barium (Ba) and sulfur (S) in the k7 coal seam of the Karaganda Coal Basin, Central Kazakhstan, focusing on their average concentrations, spatial variability, and the principal geological and mineralogical factors controlling their accumulation in coal, clay layers, and coal-clay contact zones. Methods. The study is based on 85 samples collected from the k7 coal seam at the Saran, Aktas, and T. Kuzembayev mines, representing coal, clay layers, and coal-clay contact zones. Sample preparation was conducted at Azimut Geology LLP (Karaganda), followed by geochemical analysis using inductively coupled plasma optical emission spectrometry (ICP-OES) and inductively coupled plasma mass spectrometry (ICP-MS). The analytical data were evaluated using statistical and correlation methods to determine the average concentrations, vertical and lateral distribution patterns of Ba and S, and their associations with major rock-forming components. Findings. The results demonstrate pronounced vertical and lateral heterogeneity in the distribution of Ba and S within the k7 seam. Barium is predominantly concentrated in clay layers and coal–clay contact zones, indicating a mainly clastogenic and sorption-controlled accumulation mechanism associated with aluminosilicate minerals. Positive correlations of Ba with Al2O3 and K2O suggest its association with kaolinite and hydromica. In contrast, sulfur is mainly concentrated in coal, particularly near the upper and lower parts of the seam, reflecting the influence of diagenetic and epigenetic processes and its association with sulfide phases. Originality. The study provides a comparative assessment of the contrasting geochemical behavior of Ba and S within the same k7 coal seam, with particular emphasis on their vertical and lateral distribution patterns and associations with mineral and geochemical components. The results indicate differences in the factors controlling the accumulation and distribution of these elements, with Ba predominantly associated with clastic and sorption processes, whereas S distribution is influenced by diagenetic and epigenetic processes. These findings contribute to a more detailed understanding of the geochemical heterogeneity and formation conditions of the Karaganda Coal Basin. Practical implications. The identified distribution patterns of Ba and S can be used to assess the industrial and environmental characteristics of the k7 coal seam. Ba-enriched clay layers and coal-clay contact zones, as well as S-enriched upper and lower parts of the coal seam, may serve as indicators for targeted geochemical assessment. The results can also contribute to evaluating Karaganda coals as potential unconventional sources of valuable associated elements and support more effective geochemical monitoring and the rational utilization of coal resources.

This paper presents the results of a comprehensive mineralogical study of oxidized copper-porphyry ore from the Koktashal deposit. Optical microscopy, silicate analysis, and quantitative phase analysis were used to characterize the mineral composition and forms of copper occurrence in the oxidation zone. The ore contains 0.735% total copper, of which 89.8% occurs in oxidized form, 6.39% in primary sulfides, 2.72% in secondary sulfides, and 1.09% in water-soluble form. The principal ore minerals are malachite (1.5–2.0%) and azurite (0.3–0.4%), accompanied by hematite with magnetite (0.5%), goethite (0.2%), and pyrite (0.2%), whereas copper sulfides and native copper occur only in trace amounts. The integration of classical mineralogical methods with quantitative phase analysis provides new insights into the distribution of copper occurrence forms and their relationship to oxidation processes. Malachite and azurite occur as well-crystallized vein and nest aggregates as well as colloform earthy masses developed along microcracks in association with iron hydroxides. Their close association with iron hydroxides and the near absence of copper sulfides represent a diagnostic feature of the oxidation zone in copper-porphyry systems. These findings improve the assessment of supergene alteration during exploration and support the classification of oxidation-zone ores as a distinct geological and industrial type for reserve estimation, ore body delineation, and processing scheme selection.

Purpose. To study mineralogical and geochemical characteristics of Koktaszhal porphyry copper deposit in order to reveal regularities of porphyry copper ore formation and develop exploration criteria. Methodology. The research applies modern mineralogical and geochemical approaches including XRF (X-ray fluorescence), optical emission spectrometry (ICP-OES), X-ray diffraction analysis (XRD), chemical analysis and phase analysis, as well as analysis of literature and library materials. Findings. Complex mineralogical and geochemical studies of ores of Koktaszhal deposit revealed a complex structure conditioned by porphyry copper mineralization and zonal distribution of its components. Geochemical analysis revealed the prevalence of SiO2, Al2O3 and Na2O in the ore composition. Comparison of oxide and sulphide ore analyses determined a clear spatial and geochemical differentiation of ore components, which reflects different stages of ore formation. It was found that in oxide ore 79.5 % of copper is associated with malachite and azurite, and in sulphide ore, 79 % of copper is associated with bornite. The supergene alteration zone is enriched in Bi, Pb, Co, Ni, which indicates the migration of these elements in the weathering zones, while the sulphide zone is characterized by stable content of Mo, Sb and Ag, which confirms the primary-sulphide nature of the studied mineralization and its formation under low temperature conditions. X-ray diffraction and electron microscopic analyses revealed predominance of quartz, albite, muscovite and other silicates, which confirms the presence of intensive processes of argillisitization and sericitization. The results of thermogravimetric analysis showed high thermal stability of the ore and predominance of thermally stable minerals. The results obtained make it possible to clarify the morphology of ore bodies, to identify geochemical criteria for exploring and evaluating porphyry copper objects, as well as to substantiate directions for ore processing optimization. Originality. The porphyry copper mineralization of Koktaszhal deposit was comprehensively researched using modern analytical and statistical methods. For the first time, a complex interpretation of mineralogical and geochemical characteristics of ores was performed taking into account their spatial variability and influence of tectonic faults. The research identified new genetic features reflecting the stages of fluid mineralization, as well as diagnostic parameters allowing reliable differentiation of ore types. Practical value. The obtained results can be used in ore bodies modelling and planning of exploration works at the stage of assessment and revaluation of reserves of porphyry copper deposits of Central Kazakhstan.

Porphyry copper deposits are the source of most of the world's copper, molybdenum and significant amounts of gold. This makes them a major focus of scientific research due to their economic significance. The article is devoted to the study of the geochemistry of host rocks and copper-porphyry ores at the Nurkazgan deposit. It identifies geochemical criteria for the distribution of gold in copper‑porphyry systems, as well as refines ore formation mechanisms in order to improve predictive criteria. The results were obtained by interpreting analytical data obtained using the ICP-OES (ICP-AES) method and the geostatistical method. Based on this research, key factors have been identified that determine the distribution of element content. As a result of studying the distribution of REEs in the host rocks, conditions for ore formation were established: the deposit has an igneous origin with signs of prolonged fractionation of the magma; a negative Eu anomaly confirms the involvement of plagioclase fractionation typical of medium and acidic magmas; LREE enrichment indicates an evolved magma involving the continental crust, while moderate depletion of HREE indicates a deep source of magmatism with residual garnet involvement. The established strong positive correlation between REES indicates a single geochemical process and reflects the primary magmatic identity. A porphyry system with a deep magmatic source has been revealed, where ore fluids are separated from the residual melt, which is already depleted in Eu but enriched in LREEs and metals.

The article presents a study on the geochemical characteristics of the ore deposits in the Bakyrchik ore area (Bakyrchik, Glubokiy Log, Zagadka, Promezhutochnoe), which is located in the Zharminsk district of the Abay region in Eastern Kazakhstan.The aim of the study is to identify and describe the geochemical characteristics of the ore deposits in the Bakyrchik ore field, and to analyze the distribution and zonation of elements within ore bodies and areas of dispersed mineralization. The results of spectral analysis on 30 rock samples collected from various depths (550–700 meters) in the vertical mineralization profile of the Bakyrchik field. Samples were taken from core material from different wells in different areas of the field, including Bakyrchik, Glubokiy Log, Zagadka, and Promezhutochnoe, as well as from zones of ore bodies and other areas such as zones of fracture, mylonite, calcite, and sulfide mineralization, considering lithological features. Based on the results of geochemical studies conducted, the characteristics and differences in geochemical properties of large and small ore deposits have been identified, and the distribution of chemical elements within zones of dispersed mineralization has been described. The practical significance of this work lies in the fact that the revealed patterns of element distribution and geochemical zoning to predict the presence of new ore deposits, interpret chemical anomalies, estimate the level of erosion of mineralization, and optimize exploration and assessment efforts in other areas within the ore field.

Due to the gradual depletion of traditional metallic mineral resources, the search for new potential sources is an important issue. One such source is coal deposits. The extraction of metals from coal is a way to produce clean energy. This study presents the results of detailed research on geochemical features and mineralogy to understand the processes of microelement enrichment in the coal-bearing deposit of Shubarkol, in Central Kazakhstan. Modern analytical techniques were used to obtain information about the conditions and processes of trace element accumulation in coal, as well as the modes of occurrence of these elements. Geochemical data were analyzed using multidimensional statistical methods, including correlation, clustering, and factor analysis, which allowed us to draw several scientific conclusions. Numerous factors indicate that the enrichment of trace elements in sediments is controlled by clastic terrigenous material and low-temperature hydrothermal solutions circulating in the coal basin. The main sources of removal of trace elements from coal are ancient igneous rock complexes located within deposits that were directly involved in coal enrichment through secondary geological processes. According to estimates, the degree of enrichment of Jurassic coals at Shubarkol was close to the average value for world coals (0.5 < CC < 2), and coal seams were enriched with lithophilic and chalcophilic elements such as Ba, U, Yb, Co, La, Nb, Hf, Sc, V, Sr, Cu, and Zn. A correlation analysis of coal deposits revealed a significant correlation between main oxides and rare earth elements (REEs). The strongest correlation was between Zr, Hf, Th/Ta, and REEs. The positive correlations between Zr and Al₂O₃, Nb and Al₂O₃ indicate that these elements (Zr, Hf, Nb, Ta, and REY) are probably related to Al. The results obtained make it possible to consider coal as a potential mineral resource for the production of rare metals and serve as a guide for the industrial processing of the most important elements found in coal.

Software tools for solving geological problems, estimating mineral reserves and taking them into account in the design and planning of mining operations are an important and responsible part of mining and geological information systems. The structural features of the geological environment determine all key technological solutions for the development of deposits, therefore, the creation of models adequate to real objects is one of the main goals of the geological service. The paper presents data on the analysis of the effectiveness of using the Grade Copilot within Micromine software for geological data processing. The primary features and benefits of this instrument in enhancing the precision and expediting geological data analysis are discussed.

We investigated the distribution patterns and evaluated the average contents of trace elements in the k₇ seam of the Karaganda coal basin in Central Kazakhstan. This paper presents the results of studying the geochemistry of 34 elements in 85 samples of the k₇ seam. The study employed a suite of advanced high-resolution analytical methods, including atomic emission spectrometry with inductively coupled plasma (ICP–OES) and mass spectrometry with inductively coupled plasma (ICP–MS), along with their processing and interpretation. It was determined that the concentrations of trace elements in the k₇ seam are primarily associated with lithophile elements, revealing high concentrations of Li, V, Sc, Zr, Hf, and Ba. Additionally, increased concentrations of Nb, Ta, Se, Te, Ag, and Th were observed compared to the coal Clarke. Specific Nb(Ta)–Zr(Hf)–Li mineralization accompanied by a group of associated metals (Ba, V, Sc, etc.) was identified. The study revealed lateral and vertical heterogeneity of the rare elements’ distributions in coals, attributed to the formation dynamics of the coal basin. A correlation between Li and Al₂O₃ with a less positive relationship with K₂O suggests the affinity of certain elements (Li, Ta, Nb, and Ba) to kaolinite. Clay layers showed increased radioactivity, with Th—13.2 ppm and U—2.6 ppm, indicating the possible presence of volcanogenic pyroclastic rocks characterized by radioactivity. Taken together, these data reveal the features of the rock composition of the source area, which is considered a mineralization source. According to geochemical data, it was found that the source area mainly consists of igneous felsic rocks, indicating that the formation occurred under conditions of a volcanic arc. This study’s novelty lies in estimating the average trace elements in the k₇ seam, with elevated concentrations of certain elements that suggest promising prospects for industrial extraction from coals and coal wastes. These findings offer insights into considering coal as a potential source of raw material for rare metal production, guiding the industrial processing of key elements within coal. The potential extraction of metals from coal deposits, including from dumps, holds significance for industrial and commercial technologies, as processing critical coal elements can reduce disposal costs and mitigate their environmental impact.

A comprehensive assessment of the critical elements contained in coal is essential for understanding the geological processes that affect the enrichment of these elements, which can then be used to fully utilize coal in an economically and environmentally friendly manner. In order to understand the geology of an area and the impact of demolition rock on the formation and enrichment of trace elements, as well as rare earth elements (REE) in coals, we have presented a range of recent geochemical and mineralogical data from the k₇ coal seam in the Karaganda Formation of the Karaganda Coal Basin. The study revealed that the geochemical characteristics of coal-bearing deposits in the Karaganda Basin reflect the features of its geological evolution. Despite high tectonic activity and volcanic activity in the Paleozoic era, the specific composition of the rocks on the slopes and bases of coal-bearing valleys has determined the low potential for rare metals in the basin. It has been found that the coal in the Karaganda Basin is, in general, similar in terms of concentrations of most trace elements to the average for world coal. The main area of provenance of the trace elements was established using discriminant diagrams. It was established that the main source of the trace elements, including REEs in the basin coals, was the Tekturmas accretionary complex that represented the main upland (anticlinorium) during the coals’ formation. SEM studies identified micro-mineral forms that indicated the presence of trace elements of Zr, Ti, Se, and Fe in the samples of stratum k₇.

This research presents the results of a comprehensive study of mineralogical and geochemical features of REE distribution in coals of Central Kazakhstan deposits—Karaganda coal basin and Shubarkol deposit, which have large hard coal reserves and are industrially important for the coal industry of Kazakhstan; the research is based on 205 samples of clayey interlayers and coal seams. It shows basic patterns of distribution and features of concentration for impurity elements, gives an estimate of the impurity elements concentration, including REE, defines conditions and factors of their accumulation, and studies features of their forms in coal and coal-bearing rocks, which allows estimating the mechanisms of their migration and conditions of accumulation. According to the results of geochemical indicators, the article establishes the factors of REE dislocation, reveals the composition of margin rocks that have influenced REE concentration in coal seams, and the presented latest data on mineralogy allowed to establish the ways of their transportation to the paleobasin during the syn- and epigenetic periods of formation of the coal deposits of Central Kazakhstan being researched. It was found that the coals are insignificantly enriched with heavy lanthanides from Ho to Lu. The distribution curves of UCC normalized REE values in the coals are similar and coincide, but they are less than the average value for world coal, and amount to only one-third of the UCC. It was found that the highest concentrations of all REE are characteristic of clayey interlayers and oxidized coals. The La/Yb ratio in this case increases upwards along the section, indicating mainly clastogenic mechanism of REE delivery to the coals. In coal and clay samples, the predominant mineral form of REE is light lanthanide phosphates. Identified particles of REE from minerals and their composition peculiarities suppose autigene nature of their formation. The formation of the bulk of autigene minerals occurred during the maturation of brown coals and their transformation into hard ones.