Purpose.Determination of the rock stability along the strike of the mass, where the drift mining of the horizon -480 m is conducted, considering the possibility of using the improved types of supports in the conditions of the 10th Anniversary of Kazakhstan’s Independence mine at the Khromtau field with the substantiation of using the effective type of fastening that increases technical and technological, operational and economic indicators of the mine. Methods. Numerical modelling of the stress-strain state of the rock mass applied at the mine have been performed using the RS2 software in a two-dimensional formulation. The rock mass state, as well as the physical-mechanical properties of mine rocks are determined according to building codes and regulations (SNiP II-94-80), depending on the category of the rock stability. Findings. It has been revealed that the combined supports from rock bolts and shotcrete are the most rational type of fastening in the studied mine. The efficiency and prospects of using the combined supports have been determined, which ensure a decrease in their material consumption and cost while increasing the reliability of mine workings and the labor productivity of miners. The use of combined support allows to increase the economy of materials for support by 1.7 times, as well as to increase the drifting rate by 1.6 times in comparison with the metal support. Originality.The paper proposes a new approach to substantiation of an effective fastening method by comparing the costs when driving horizontal underground mine workings in the mining-and-geological conditions of the 10th Anniversary of Kazakhstan’s Independence mine. Practical implications.The research results can be used when planning mining operations, in particular, stable fastening methods at the 10th Anniversary of Kazakhstan’s Independence mine of the Khromtay deposit, as well as other mining enterprises with similar mining-and-geological conditions.

Purpose is to identify the basic joint systems, their characteristics, distribution within the rock mass, and determine impact of the joints on the bench stability. Methods. The risks of strain emergence in the form of blocks sliding along weakness surfaces within the local areas were determined based upon the definition of rock stability loss. The results of large-scale measurements of jointing were processed using circular and bar diagrams as well as stereographic grids. In the context of the paper, kinematic analysis was implemented through Dips Rocscience Inc. Software. Findings. Five basic joint systems have been identified; joints of 2nd and 5th systems are the most commonly encountered among them. The results of the jointing determination within the open pit boundaries have been represented as well as the open pit wall stability in terms of each site inclusive of consideration of potential strains along the sliding surface. Originality. For the first time, zoning of the open pit wall in terms of slide types has been performed. It has been identified that potential shear of a prismatic block is 33%; at the same time, 66% are bench destruction with the block toppling. The risk of wedge-shaped block shear is minimal. Practical implications. The research findings may be helpful to define and select both parameters and conditions of safe mineral extraction under the specific mining and geological conditions. In turn, the abovementioned will help reduce the risk of accidence while providing scientifically substantiated approach to select quarrying sequence, techniques, and system.

The paper presents the results of studies on the sorption leaching of gold-containing ore of the Vasilkovskoye deposit. Kinetic dependences of the sorption of gold and associated metals from cyanide-alkali solutions under different physical and chemical factors were obtained. It was found that gold on the AM-2B resin sorbed at a higher rate than, for example, copper and zinc. The solutions were analyzed using modern devices of a new generation: FT-IR spectrometer "Avatar 370". Laboratory studies were performed to determine the gold sorption rate by the AM-2B anionite from cyanide-alkaline solutions. It was found in the process of sorption of gold from multicomponent cyanide-alkali solutions on AM-2B anionite of mixed basicity, with the macroporous structure containing benzyl dimethylamine and dibenzyl dimethyl ammonium functional groups, that an important factor of qualitative and quantitative separation of gold and impurity metals is the concentration of cyanide and hydroxyl ions in solution. The temperature effect on the sorption rate of gold from cyanide-alkali solutions was studied with the temperature dependences F of t, Bt, of t, ln (l - F) of t, and D of t that show that the sorption process of dicyanoaurate ions is controlled by mixed diffusion.

Purpose.The research aims to conduct a comprehensive study on substantiation and selection of optimal parameters for supporting mine workings at deep levels by analyzing the stress-strain state (SSS) of the rock mass, modeling geomechanical processes and developing effective strengthening technologies in difficult geological conditions. Methods. The research includes modeling of the stress-strain state of the rock mass using ANSYS, Phase2 and Prorock software packages. To assess and predict the stress-strain state of the mass in the area of stope blocks, a series of numerical experiments have been conducted to analyze the near-contour rock mass stability. The physical-mechanical characteristics of ores and host rocks are used as input data for modeling. Findings. The mass SSS analysis has confirmed that increasing the number of cable bolts up to four provides mine wor-king stability, but is accompanied by intensive fracture formation beyond the contour, as well as convergence up to 14 cm, which requires the use of reinforcing mesh and reinforcing frame in two layers. The mining system elements have been found to provide the necessary safety factor for end ore drawing (ks ≥ 3.0) and slicing mining with hardening backfill (ks ≥ 5.0). Originality. The parameters for supporting mine workings have been substantiated, which ensures safe mining of deep levels. It has been revealed that when backfilling, the height of the caving zone is 125 m and the fracture zone is 60 m. For mining systems with caving, these figures reach 280 and 470 m, respectively. Practical implications. The technology has been developed for supporting capital mine workings with the use of reinforced combined support and roof bolts. The results obtained contribute to the improvement of reliability and efficiency of mining operations by providing accurate prediction of rock behavior under conditions of changing stresses and reduction of their strength characteristics.

Purpose. To study gold-bearing ores subjected to heap leaching technology to identify both free gold particles, as well as gold in aggregates and adhesions, which makes it possible to obtain data on the distribution of gold by its occurrence forms. Methodolgy. Leaching process studies are conducted at the laboratory setup of the Institute of Metallurgy and Ore Beneficiation of the Ministry of Education and Science of the Republic of Kazakhstan. The gold particles are studied using an AxioScope A1 optical microscope on the polished thin section surface. The sample materials are taken from the heap leaching site of the Vasilkovsky gold ore deposit. Findings. As a result of a microscopic test of a sample taken from the heap leaching site, ultrafine-dispersed and finely-dispersed gold particles have been found both in free form and in aggregates with waste rock and arsenical pyrite, as well as the fact of Au particles adhesions, accumulated on a grain of the host waste rock. The size class of detected Au particles varies from 0.35 to 9.5 m. Originality. For the first time, according to the samples of gold-bearing ores of the Vasilkovsky gold ore deposit, a pattern of the gold distribution according to the forms of its occurrence has been revealed. Practical value. The data obtained as a result of the research make it possible to predict the distribution of the gold form occurrence in other areas of the deposit. This can greatly simplify the conditions for its development, as well as adjust the technological process of leaching the gold-bearing ores and the main technological parameters of the heap leaching process.

Purpose. The primary goal of this study is to conduct a comprehensive geomechanical assessment of the rock mass at the Voskhod deposit in order to optimize ore extraction techniques through numerical modelling and to evaluate the effect of pillar width on the stability of mine workings under complex mining and geological conditions. Methodology. The study employs advanced numerical modelling techniques using Phase2 and RocLab software, enabling the simulation of realistic mining scenarios. The empirical Hoek–Brown failure criterion, integrated into stress-strain models, serves as the principal tool for evaluating the mechanical behaviour of rock masses. Laboratory testing data – including uniaxial compressive and tensile strengths, elastic modulus, cohesion, Poisson’s ratio, and other physical and mechanical properties – were utilized to generate strength classification charts for rock groupings. Findings. The simulation outcomes indicate that reducing the width of protective pillars from 12 to 10 m significantly decreases the load-bearing capacity of the rock mass. This is manifested by an expansion of zones with insufficient strength reserves and a deterioration in the condition of inter-level pillars. Measurements from reference stations revealed that displacement rates increased more than fourfold during the transition from active mining to stabilization phases. Moreover, decreasing the distance to the production face led to an even more pronounced increase in deformation. Originality. The novelty of the study lies in the integration of modern numerical modelling tools with in situ monitoring data, enabling the identification of critical dependencies between the geometry of mine workings and the dynamic response of the surrounding rock mass. Practical value. The results obtained can be used to optimise the ore extraction technology at the Voskhod deposit, improve mining safety and reduce economic losses associated with cave-ins and emergencies.