STUDY OF THE LOCATION AND MINERALOGICAL COMPOSITION OF OFF-BALANCE ORES AT THE KALMAKYR DEPOSIT

УДК 669.01

Abstract

This scientific article comprehensively examines the technical, economic, and mineralogical foundations for the efficient processing and utilization of out-of-balance (sub-economic) copper ores and technogenic waste deposits originating from the prominent Kalmakyr deposit. As a primary core of this research, a detailed geo-technological assessment of 10 strategic technogenic waste storage facilities and tailings dumps located within the mining area was meticulously conducted. The comprehensive quantitative analysis revealed vast industrial reserves exceeding 103.2 million tons of technogenic ore mass, which critically contains valuable components amounting to 315.5 thousand tons of copper and 39.4 tons of gold. Advanced laboratory investigations and mineralogical analyses demonstrated that these out-of-balance raw materials possess a complex, highly refractory aluminosilicate base with intricate mineral intergrowths. Due to the inherent economic inefficiency and technological limitations of applying traditional froth flotation methods to such low-grade technogenic formations, this study proposes a paradigm shift in processing methodologies. Consequently, the research evaluates and justifies the implementation of advanced heap leaching utilizing sulfuric acid solutions, integrated within a combined innovative technological scheme that pairs hydrometallurgical and gravity-flotation circuits. The integrated approach successfully achieves optimal metal recovery rates, mitigates metallurgical losses, transforms hazardous industrial waste into profitable assets, and significantly reduces the overall environmental footprint of the Almalyk Mining and Metallurgical Complex.

Аннотация

В данной научной статье комплексно рассматриваются технические, экономические и минералогические основы эффективной переработки и утилизации забалансовых медных руд и техногенных отходов, образовавшихся на крупном месторождении Кальмакыр. В качестве ключевого ядра исследования была проведена подробная геотехнологическая оценка 10 стратегических отвалов и хранилищ техногенных отходов, расположенных на территории рудника. Комплексный количественный анализ выявил колоссальные промышленные запасы, превышающие 103,2 млн тонн техногенной рудной массы, которая содержит ценные компоненты в количестве 315,5 тыс. тонн меди и 39,4 тонны золота.

Глубокие лабораторные исследования и минералогический анализ показали, что данное забалансовое сырье имеет сложную, труднообогатимую алюмосиликатную основу с тесным взаимным прорастанием минералов. Ввиду очевидной экономической неэффективности и технологических ограничений применения традиционных методов пенной флотации для столь бедных техногенных образований, в данном исследовании предлагается принципиальное изменение методологии переработки. В связи с этим в работе обосновывается внедрение передового кучного выщелачивания с использованием растворов серной кислоты, интегрированного в комбинированную инновационную технологическую схему, сочетающую гидрометаллургический цикл и гравитационно-флотационные процессы. Интегрированный подход позволяет достичь оптимальных показателей извлечения металлов, снизить металлургические потери, превратить экологически опасные промышленные отходы в прибыльные активы и существенно сократить общую экологическую нагрузку на Алмалыкский горно-металлургический комбинат (АГМК).

Keywords: Kalmakyr deposit, off-balance ore, technogenic waste, copper, gold, mineralogical composition, heap leaching, hydrometallurgy.

Ключевые слова: месторождение Калмакыр, забалансовая руда, техногенные отходы, медь, золото, минералогический состав, насыпной выщелачивание, гидрометаллургия.

Introduction

The current stage of the mining industry's development is characterized by a sharp decline in reserves of highly conditioned and easily enriched ores, which in turn makes the processing of low-concentration and off-balance ore accumulated at large sites such as the Kalmakyr deposit a pressing scientific problem. Despite the fact that these man-made raw materials contain valuable components such as copper, gold, and silver, the complexity of their mineralogical composition and the scattered nature of the metals cause economic inefficiency when using traditional flotation methods. The scientific approach of the study is that off-balance ore is no longer a simple waste, but is being re-evaluated as a strategic reserve that must be developed in the future due to expected changes in technological and economic conditions. The proposed hydrometallurgical and combined enrichment methods serve to maximize the extraction of useful ore components, reduce production costs, and expand the raw material base of the Almalyk Mining and Metallurgical Complex.

In the context of the rapid depletion of high-grade ore reserves in the modern global mining industry, the "waste-to-resource" strategy, using the Kalmakyr deposit as an example, has become the most relevant scientific and practical direction for expanding the raw material base. The object of research is considered to be an off-balance ore mass of oxidized (83.3 million tons) and mixed (32.2 million tons) in the total volume of 115.5 million tons, which indicates the presence of a large technogenic resource base in the area of the deposit. Although the copper content in these ores is lower than industrial standards, averaging from 0.10% to 0.15% (gold 0.5–0.6 g/t, silver 3.0–5.0 g/t), the scale indicators of the total volume guarantee the economic profitability of their processing. Analysis of samples taken from 10 strategic landfills (including A9, A7, 8a) showed that the total ore content is more than 103.2 million tons, and the total metal reserves are 315.5 thousand tons of copper (average 0.328%), more than 39.4 tons of gold and 137.1 tons of silver. The mineralogical composition of these ores poses a complexity for traditional flotation methods, as the minerals are finely dispersed and have a high oxidation state, leading to significant metal loss and an increase in the environmental burden.

The proposed combined (hybrid) approach to solving the problem involves integrating the stages of mechanical preparation and enrichment with hydrometallurgical processes. Heap Leaching using H₂SO₄ (sulfuric acid) was selected as the central link of the technological chain, characterized by its low cost and energy efficiency.

Additionally, the implementation of innovative solutions such as bioleaching (bacterial smelting), microwave processing, and sensor sorting will help maximize the metal recovery coefficient. Such a large-scale development model not only increases the economic capacity of the Almalyk Mining and Metallurgical Complex but also serves as a universal scientific solution for large mining districts such as Muruntau, Kokpatas, and Zarmitan, restoring ecological balance by reducing waste areas in the region.

Figure 1. 10 selected waste dump areas at the Kalmakyr mine

In order to create a feasibility study for the development of off-balance ore at the Kalmakyr deposit, 10 strategic regions were selected as shown in Figure 1 within the framework of the study, and a fundamental database of their raw material potential was formed. The obtained numerical analysis shows that in total, more than 103.2 million tons of ore mass are concentrated in these regions (A9, A7, 10, A1, 2, A8, A4, etc.), containing 315.5 thousand tons of copper, more than 39.4 tons of gold, and 137.1 tons of silver. Specifically, the average content of copper in the total reserve is 0.328%, gold is 0.462 g/t, and silver is 2.176 g/t, which serves as grounds for recognizing these sites not merely as waste, but as man-made deposits of high value.

Table 1. The total volume of the 10 selected tailings dumps of the Kalmakyr deposit

Once the volumetric parameters of this vast raw material base were determined, the in-depth study and analysis of the mineralogical composition of the ores were designated as the next critical scientific stage. This process is of decisive importance in ensuring the efficiency of the chosen technological scheme, as the chemical and mineralogical properties of the ore directly determine the methods of metal extraction (flotation or hydrometallurgy). As a result of laboratory analyses, it was determined that in the samples presented in Table 2, the content of silicon dioxide (SiO₂) is 54.71% and aluminum oxide (Al₂O₃) is 14.21%, which indicates that the ore has an aluminosilicate base. At the same time, the total iron content is 7.01%, the bulk of which occurs in the oxidized form, indicating the complex textural and structural characteristics of the ore and the degree of metal dispersion.

Based on these mineralogical analyses, a scientific strategy was developed for the processing of these off-balance ores, which contain 0.699% copper and 1.39 g/t of gold, using acid leaching or combined innovative methods.

Table 2. Mineralogical composition of the oxidized ore sample from the general waste dump

Conclusion

Research conducted on the processing of off-balance ore from the Kalmakyr deposit shows that, amidst the depletion of rich ore reserves on a global scale, the development of an industrial raw material base of approximately 115.5 million tons is a strategic direction ensuring the future sustainable development of the Almalyk Mining and Metallurgical Complex. Analysis of samples taken from 10 landfills confirmed that precious metals such as 315.5 thousand tons of copper and more than 39.4 tons of gold are concentrated in these areas, the total volume of which, despite the low metal content, fully justifies the economic profitability of processing. As a result of mineralogical research, the aluminosilicate base and high oxidation properties of the ores were identified, necessitating the application of combined technologies over traditional flotation methods. The proposed innovative hydrometallurgical approaches, such as heap leaching and bioleaching using sulfuric acid, allow for a significant reduction in production costs while maximizing the metal recovery coefficient. The final results show that the industrial development of off-balance ore not only yields additional metal and economic benefits but also plays an important role in ensuring regional environmental sustainability by reducing the environmental burden on the mine area and reducing waste areas.

References:

1. Karshiboyev Sh.B., Sayfullayeva D.A. Processing of off-balance ores: challenges and technological Solutions., June, 2025.
2. Karshiboyev Sh.B., Sayfullayeva D.A. Balansdan tashqari rudalarini qayta ishlash texnologiyasini tanlashdagi ahamiyatI. Scientific journal of Construction and Education ISSN 2181-3779, 2025 Maxsus son-3.
3. Jia Y., Ruan R., Qu J. et al. Multi-Scale and Trans-Disciplinary Research and Technology Developments of Heap Bioleaching. Minerals, 2024, 14(8), 808. DOI: 10.3390/min14080808.
4. Sodikov, F. S., Jeong, Y., Usenov, R. B., Ibragimov, I. S., & Xolmatova, S. U. (2026). Pilot plant tests for acid leaching of low grade copper oxide ores from kalmakyr copper mine. Fars International Journal of Education, Social Science & Humanities., 14(2), 219-226.
5. Watling H.R. From Understanding the Rate Limitations of Bioleaching Mechanisms to Improved Bioleach Process Design. Hydrometallurgy, 2023, Vol. 221, 106148. DOI: 10.1016/j.hydromet.2023.106148.
6. Tezyapar Kara I., Kremser K., Wagland S.T., Coulon F. Bioleaching Metal-Bearing Wastes and By-Products for Resource Recovery: A Review. Environmental Chemistry Letters, 2023, 21, 3329–3350. DOI: 10.1007/s10311-023-01611-4.  
7. Latyuk E., Goryachev A., Melamud V., Bulaev A. Hydrometallurgical Processing of a Low-Grade Sulfide Copper–Nickel Ore Containing Pt and Pd. Processes, 2024, 12(6), 1213. DOI: 10.3390/pr12061213.
8. Dixon D.G., Petersen J. Heap Leaching of Low-Grade Copper Ores: Current Status and Future Perspectives. Minerals Engineering, 2022, Vol. 182, 107564.
9. Zhang Y., Li X., Wang H. Advances in Hydrometallurgical Processing of Oxidized Copper Ores. Hydrometallurgy, 2024, Vol. 226, 106320.
10. Sodikov F.S., Ibragimov I.S., Usenov R.B. Innovative Technologies for Processing Technogenic Mineral Resources in Uzbekistan. Mining Informational and Analytical Bulletin, 2025, No. 12, pp. 45–53.
11. Abdurakhmonov A.A., Rakhimov B.B., Tursunov O.T. Technological Assessment of Low-Grade Copper Ore Processing by Heap Leaching Method. Mining of Mineral Deposits, 2022, Vol. 16(4), pp. 65–73. DOI: 10.33271/mining16.04.065.
12. Nurmatov J.S., Usmanov A.K., Ergashev B.T. Prospects for Utilization of Technogenic Mineral Resources and Off-Balance Ores in Uzbekistan. E3S Web of Conferences, 2025, Vol. 612, Article 01018. DOI: 10.1051/e3sconf/202561201018.