Crushed Coal Research Articles

Calibration method of discrete element parameters of crushed coal based on mechanical and engineering tests

Current discrete element parameter calibration methods primarily rely on mechanical tests to analyze particle properties and often overlook the machinery's interaction with the particles. The extensive variation in particle sizes of crushed coal poses challenges in accurately applying parameters derived from mechanical test calibrations to industrial simulations. DEM models of mechanical tests for coal were developed to examine how parameters influence coal's mechanical properties through factor analysis. Simplified engineering test models were developed based on mining equipment, with the equipment responses used as indicators to optimize mechanical test calibration parameters. On this basis, a calibration method of discrete elemental parameters of coal based on the crushing simulation of mining equipment was proposed. This method was validated through mechanical and engineering simplification tests, resulting in a mean error of <10 % in the time-varying response. The research findings enable calibration of discrete element parameters for crushed coal in industrial simulation.

Experimental study on mechanical properties and damage mechanism of self-stress grouted crushed coal of different grain sizes

The reinforcement mechanism of self-stress grouted crushed coal of different grain sizes is not clear. In this study, crushed coal of 5∼10, 10–20 and 20∼30 mm grain was selected. It obtained that the grain size was proportional to the width of sedimentary fissure among coal blocks and inversely proportional to its distribution range. As coal grain size increases, the uniaxial compression strength (UCS) of grouted specimens decrease and the AE parameters increase, respectively. The slurry forms a mesh skeleton structure in the 5∼10 mm specimen, significantly increasing its bearing capacity. However, in the 20∼30 mm specimen, the porous coal block is the main carrier, reducing the bearing capacity. Swelling needle-like Aft crystals produced closely occludes the coal, increasing the binding ability and overall compactness; almost none of the coal-slurry intersections are damaged during uniaxial compression. The main damage areas of 10∼20 mm and 20∼30 mm grouted specimens are inside coal by SEM, and the cracks increase with the rise of coal grain size. The trends of damage variable and cumulative energy counts curves are approximately the same, further confirming the reliability of the analysis of the AE experimental results. This paper can lay the foundation for theoretical research and field practice of self-stress grouting reinforcement.

Experimental Study on Compaction Deformation and Gas Permeability Properties for Crushed Limestone.

The mining goaf is enriched in coalbed methane (CBM) resources, and it is imperative to realize its efficient extraction. The gas permeability properties of the crushed coal and rock in the caved zone of mining goaf are the basis for the study of its internal CBM migration and enrichment law. In this study, the compaction deformation and gas permeability properties of crushed limestone with different particle sizes were revealed. The results show that (1) the deformation resistance capacity of the crushed limestone increased with increasing stress. The decreasing trend of porosity of samples with different particle sizes in the early and later compression periods is significantly different. Particle RR of the lower layer is smaller than that of the other layers. (2) The permeability of the sample decreases with decreasing porosity and nitrogen pressure, and it is between 10-12 and 10-10 m2. Nitrogen migration within the crushed limestone requires the pseudo-threshold pressure gradient, which ranges from 64.86 to 311.42 Pa/m. (3) The average permeability growth amplitude of the sample shows a logarithmic decreasing trend with the decrease of porosity. The average permeability growth amplitude of the 5-10 mm sample at the same porosity was 15.9-22.3 times that of the 0.315-0.63 mm sample. (4) The permeability of crushed limestone on both sides of the lower layer in the caved zone is much larger than that of other locations. The results are of great practical significance for accurately predicting the CBM enrichment area of mining goaf and then selecting the final position of the extraction drilling hole.

Evolution law of coal and gas outburst hole shapes with varying underground stress conditions: Numerical analysis and on-scene evidence

A rock-coal-rock excavation model was established, and a coal and gas outburst (Abbreviated as CAGO) numerical simulation was carried out, which takes into account the dual-pore model and the desorption of gas. The plastic zone expansion was simulated under the different gas pressures and lateral pressure coefficients, and the variation in hole shape was characterized by the change in the plastic zone and compared with the actual engineering. The results indicate that: (1) There is a critical time in the CAGO process that divides the gas action into two stages: the first stage is the energy that causes the destruction of the coal body and throws out the crushed coal, the pressure difference between atmospheric and gas provides energy for this. The second stage is that the pressure difference will only provide energy for the throwing of broken coal. (2) Under the same loading conditions, gas pressure is set from 0.5 MPa to 0.9 MPa in 0.1 MPa increments, the area of the plastic zone around the exposed surface increases from 1.323 m2 to 1.3238 m2, and the peak velocity is reached faster. Meanwhile, the plastic zone increased from 1.319 m2 to 1.3238 m2 under the gas pressure of 0.9 MPa. This suggests that gas also has an effect on coal seam damage, but it is relatively weak compared to the geo-stress. (3) Pre-destruction of coal by geo-stress determines the size and shape of the hole, and the lateral pressure coefficient determines the pre-destruction situation. When the coefficient is small, the hole develops into an asymmetrical butterfly shape with a larger upper part and a smaller lower part, and when the coefficient is close to 1, the hole tends to develop into a semi-elliptical shape. Finally, the simulation result was compared with the experiment and the on-scene evidence. This study has guiding significance for the prevention and control of CAGOs at different depths.

Study on the Difference in Oxidation Characteristics of Coal and Gangue from the Same Coal Seam

ABSTRACT The gangue hills and underground backfill mining gob where crushed coal and coal gangue coexist face severe risks of spontaneous combustion. Studying the differences in oxidation characteristics between coal and gangue from the same coal seam is beneficial for spontaneous combustion. This paper tested the changes in radicals, functional groups, and gas products during the oxidation of raw coal, raw gangue, and washed gangue and analyzed their differences. Finally, gray correlation analysis was used to calculate the correlation between active groups and gas. The results showed that raw coal contained a more significant initial radical concentration and g factor value than raw and washed gangue. Its aliphatic hydrocarbons and oxygen-containing functional groups content was also significantly higher. The growth rate of radical concentration in the early oxidation stage of washed gangue was larger than that of raw coal and raw gangue due to the high sulfur content. At the same time, the temperature at which the g factor started to increase rapidly and the temperature at which the aliphatic hydrocarbons decreased rapidly was lower than that of raw coal and raw gangue. Gray correlation analysis showed that the active groups closely related to oxygen consumption were CH3 and CH2, while the groups closely associated with CO generation were C=O, COOH, Ng, and g factor.

Experimental Study on the Influence of Pore Structure and Group Evolution on Spontaneous Combustion Characteristics of Coal Samples of Different Sizes During Immersion.

To study the influence of water immersion on the evolution of the groups and spontaneous combustion characteristics of coal samples with different sizes, raw coal from the Fengshuigou Coal Mine operated by Pingzhuang Coal Company in Inner Mongolia was studied. The infrared structural parameters, combustion characteristic parameters, and oxidation reaction kinetics parameters of D1-D5 water immersion coal samples were tested, and the mechanism of spontaneous combustion during the oxidation of submerged crushed coal was investigated. The results were as follows. The water immersion process promoted the re-development of coal pore structure, and the micropore volume and average pore diameter were 1.87-2.58 and 1.02-1.13 times those of raw coal, respectively. The smaller the coal sample sizes, the more significant the change. At the same time, the water immersion process increased the contact point between the active group and oxygen in the coal, and the C=O, C-O, and -CH3/-CH2- groups in coal were further promoted to react with oxygen to generate -OH functional groups and improve the reactivity of coal. The characteristic temperature of water immersion coal was affected by the temperature rise rate, coal sample size, coal voidage, and other factors. Compared with the raw coal, the average activation energy of the water immersion coal with different sizes decreased by 12.4-19.7%, and the apparent activation energy of the coal sample with a size of 60-120 mesh was the lowest on the whole. In addition, the apparent activation energy in the low-temperature oxidation stage was significantly different.

Quantitative analysis of layered re-crushing of crushed coal particles during compression based on CT scanning

Due to the compaction of the overburden strata, the crushed coal in caved zone will be re-crushed. The compaction and re-crushing degree of crushed coal differ at different heights, which is called layered re-crushing. Quantitatively revealing the layered re-crushing characteristics of crushed coal particles is the key to elucidating pore structure evolution of caved zone and coalbed methane enrichment pattern in the gob. In this paper, quantitative characterization of layered re-crushing of coal particles during compression is achieved using self-designed CT visual compacting apparatus. The results showed that: (1) the degree of particle re-crushing decreased from the loaded side (the upper layer) to the fixed side (the lower layer). In the early stage of compression, the overall skeletal structure is looser, which is not conducive to the transfer of force chains. Thus, the stress has the greatest effect on the particles in the upper layer, with the proportion of particle increase reaching 49.3% from 0 Mpa to 2.14 Mpa. There was a pattern of becoming larger first and then smaller in the difference of average diameter among different layers, and the final average diameter decreased by about 60% in three layers. (2) The particle diameter distribution transferred to a smaller diameter fastest in the upper layer and slowest in the lower layer, which is due to the gradual transfer of external load from the top to the bottom. After compression, the number of particles smaller than 4 mm predominated in the upper layer (40.3%) and the number of particles larger than 5 mm predominated in the lower layer (47.1%). (3) With the increase of stress, the void volume gradually decreases regardless of the whole sample or the three layers, while the void number increases instead. And at both 2.14 MPa and 23.24 MPa, the void volume shows the law of upper layer < middle layer < lower layer.

Experimental investigation of flow regime transition characteristics of fractured coal bodies around gas extraction boreholes

The accurate determination of the seepage flow pattern of crushed coal around the perimeter of the borehole is an important technical parameter used in the determination of the gas extraction radius. To obtain the permeability parameters of the crushed coal system, a triaxial seepage test system was designed for the crushed coal. Three flow systems of interest (pre-Darcian, Darcian, and non-Darcian Forchheimer flow systems) were investigated. The conclusions can be drawn as follows: the pre-Darcian flow state is determined at a very low Reynolds number, and there is a nonlinear phase of the seepage process of the crushed coal. The infiltration process at a low Reynolds number is basically in the pre-Darcian flow state, and its flow resistance mainly comes from the viscous force of the fluid itself. The inertia zone of crushed coal body particles starts from vs > 0.086 m/s, and the infiltration process at a high Reynolds number indicates turbulent flow. Calculation of permeability of crushed coal gives the seepage flow dividing line and critical Reynolds number values (Rep > 0.18). The improved method of calculating the pore-permeability flow regime of perforated fractured coal was used. The research can provide theoretical basis for the rational determination of the gas extraction radius.

A Study on 500 MW Coal Fired Boiler Unit’s Bowl Mill Performance through Coal Sampling and Characterization: CPRI’s Experience

Coal-fired thermal power stations presently account for nearly 52 % of the total power generation in India’s power generation sector. There is a constant need to monitor the performance of the coal-fired power plant auxiliaries/ components and ensure maintenance of these to optimum levels of operating parameters to achieve the trouble-free generation of quality and consistent electric power output. Coal’s mineralogical content and its physical parameters decide the performance of the coal pulverizer in terms of optimum ground coal output and the life of the grinding elements in the coal mills/ pulverizers. The grinding media in the pulverizes are subjected to high erosion rates owing to the presence of abrasive minerals like pyrites, alumino-silicates and hard minerals like α quartz, which are attached to the coal mass as contaminants during mining. A study was undertaken along with the Pulverizers Division of M/s. BHEL for evaluation of Coal Bowl Mill, for guaranteed performance at a 500 MW capacity NTPC thermal power plant. The study was conducted to assess the effective performance of the pulverizers of this 500 MW boiler unit for its maximum capacity of 60.9 t/hr for guaranteed coal condition and assess optimum output in terms of fineness of the crushed coal during continuous loading under the designed operating parameters. The study was also carried out to ensure that the pulverizer grinding efficiency and the effective output of the finely crushed coal were achieved by proper optimization of the mill mechanical auxillaries and their operating parameters.

About One Approach to the Construction of a Solution to the Problem of Coal and Methane Emissions from the Marginal Zone of the Formation

Based on the model of the geomechanical state of a coal massif containing a coal seam with a fragile layer, a mining working and the ideas developed by S.A. Khristianovich about gas-dynamic processes in the development of coal seams, a solving of the ejection of the marginal part of the formation is constructed. The conditions for the occurrence of gas-dynamic phenomena are formulated, which manifest themselves in the form of the formation first of a main crack in a formation with free methane, then the formation of a crushing wave in it, followed by the release of a jumper and a mixture of crushed coal and gas into mine working.

Preparation and characterization of antioxidant gel foam for preventing coal spontaneous combustion

New antioxidant gel foam is prepared to improve its stability and effectiveness in preventing coal spontaneous combustion. The physicochemical composite inhibitor is prepared by introducing procyanidins into a super absorbent polymer. And then the inhibitor is incorporated into the gel foam (surfactant, foam stabilizer, and gel system), the combined properties of foam, gel and inhibitor are utilized to prevent coal spontaneous combustion. The optimal composition ratio of antioxidant gel foam is obtained by single-factor experiments and response surface methodology. The microstructure of the foam is characterized. The properties of antioxidant gel foam in preventing coal spontaneous combustion are compared and analyzed through cementation, film-forming, and temperature-programmed experiments. The results reveal that the foam properties of the antioxidant gel foam are better when the mass fractions of surfactant, foam stabilizer, gel system, and inhibitor are 0.92 %, 0.49 %, 0.34 %, and 0.55 %, respectively. The inhibitor constitutes a high-water retention skeleton structure of foam wall and stabilizes the platform boundary. The antioxidant gel foam has small bubble size, uniform distribution, and excellent stability. The foam coarsening process is slow, which can fully wet the coal and reduce the coal temperature. Simultaneously, the antioxidant has better cementation and film-forming properties, which can cement the crushed coal and form a complete gel film, blocking the air leakage channels and isolating the contact between the coal and oxygen. Besides, the inhibition effect of antioxidant on coal spontaneous is better than that of water-based foam, polymer-stabilized foam, and ordinary gel foam. It can effectively slow down the oxygen consumption rate, gas production rate, and exothermic intensity during coal oxidation, the inhibition rate at 100 °C is 74.48 %. This study provides an antioxidant gel foam with good foam properties and inhibition effect, which can effectively reduce the oxidation rate of coal and prevent its spontaneous combustion through the physical effects on covering, wetting, and cementing, as well as inhibiting the chemical reaction between coal and oxygen.

Synthesis and properties of environmentally friendly double‐network fire fighting gel: Based on natural polymer/industrial solid waste

AbstractIn this paper, a new kind of environmental friendly double‐network gel material was prepared. The first network structure was formed by the graft copolymerization of sodium lignosulfonate (LS) and acrylic acid (AA), and the second network structure was formed by the chelation reaction of sodium alginate (SA) and carbide slag clarified solution (Ca2+). Through an orthogonal experiment, the effects of raw material addition on the compressive strength and apparent viscosity of the gel were analyzed. According to the analysis results, the optimal experimental ratio was obtained, i.e., 2 wt% of LS, 0.25 wt% of SA, 15 wt% of AA, 0.1 wt% of MBA and 0.3 wt% of APS. Furthermore, the structure of the gel are characterized by FTIR, XRD, SEM, XPS, and TG‐DTG, and the results prove that the gel successfully polymerized and a stable three‐dimensional network structure is formed. The results of water absorption experiment disclose that the gel is sensitive to ions and pH, and the water absorption rate reaches 121.25 times. In addition, the results of the air leakage experiment and fire extinguishing experiment show that the gel can effectively cover the surface of crushed coal and densely fill the gaps, demonstrating a good plugging capability and fire extinguishing capability.

Study on Permeability and Flame Retardancy of Coal Aerosol Atomized by Ultrasonic Wave

In order to analyze the permeability and particle size distribution of atomized aerosol in different coal particle sizes and to explore the inhibition performance of an atomized inhibitor in different atomization times and positions, the following conclusions are obtained by ultrasonic atomization device: The results of permeability experiment show that the particle size of aerosol decreases with the increase of atomization frequency. In addition, with the particle size of the coal sample decreasing from 5 cm to 0.6 cm, the penetration ratio of aerosol in coal decreases from 64.2% to 15.5% due to the interception of large particle size water mist by dense coal. The aerosol with a particle size of 2~4 μm has better permeability in crushed coal. The flame retardant experiment shows that compared with the raw coal, the aliphatic hydrocarbon of the atomized coal decreases by 75.9%, the aromatic hydrocarbon decreases by 57.5%, and the flame retardant effect is good. Meanwhile, the extension of solution atomization time will further enhance the flame retardant ability of ultrasonic atomized aerosol.

Effect of particle size on re-crushing characteristics of crushed coal during axial loading

The deformation and re-crushing characteristics of crushed coal and rock directly affect the porosity and permeability distribution of the mining gob and overburden strata movement, which significantly affects the methane enrichment zone and surface subsidence of mining gobs. The effect of particle size on re-crushing characteristics is investigated in this study based on an innovative compression–acoustic emission (AE) positioning method. The main results are as follows: 1) The AE counts and energy are associated closely with three deformation stages, i.e., initial compression, linear compression, and plastic compression. A larger particle deforms more easily and results in more AE counts and energy under the same compression; 2) crushed coal exhibits layered re-crushing characteristics, i.e., particle re-crushing first occurs in the middle layer, and as stress increases, re-crushing shifts gradually to the upper and lower layers; 3) larger particles re-crush more easily, and the re-crushing occurs more severely in the middle layer under the same compression stress; 4) screened results after final compression show and verify the characteristics of layered re-crushing. The lower layer exhibits the least reduction in porosity for each particle size. A larger particle exhibits a greater re-crushing rate under the same compression stress.

Measurement of the coefficient of seepage characteristics in pore-crushed coal bodies around gas extraction boreholes

Gas extraction is a form of energy extraction. The seepage and transport of gas during extraction is complex. The accurate determination of its permeation parameters is an important technical parameter. A tri-axial permeation test of the crushed grain media was designed to determine the permeation pattern of gas fuels within the crushed coal around the borehole. The resistance to gas fuel seepage was explored. The results show that: the pore structure formed by the crushed coal grains will be compressed and closed again under three-dimensional stress. The process of deformation and destruction of crushed coal grains can be divided into three stages: when the grains are subjected to a force of 1.2 kN–1.4 kN, the grains may compress each other to form a colloid. The coefficient of resistance is dependent on the permeability of the crushed coal sample, and the non-Darcian phenomenon caused by inertial loss during permeation can be characterized by the distribution of Re values f = 149.1/Re + 1.5. The two coefficients of the quadratic term in the Forchheimer equation change dynamically as the flow regime changes. This result can provide a theoretical basis for the efficient extraction of gas resources.

Investigating the effects of effective stress on pore-dependent permeability measurements of crushed coal.

The accurate determination of permeability is one of the parameters essential for the study of fluid flow and transport state. However, a large number of fractured coal bodies are faced during the production of coal mines. The study of permeability of these special media composed of grains of a certain size, whose structure is different from that of raw coal, has been in the exploratory stage. In this paper, inspired by the calculation method of median particle size and the calculation principle of KC’s equation, we calculate the permeability parameters of broken coal particles. It is considered that its permeability is closely related to the compaction and re-crushing process of skeletal grains. The lateral limit compression test of the crushed coal body was designed, and the pore-dominated permeability calculation method was given to reveal the mechanism of the action of the effective stress. The dependence relationship between the effective stress and the pore-correlation permeability is obtained by data analysis, and the force and deformation process of the crushed coal grain media is described. In contrast to the conventional Darcy series of permeability discussions, our approach excludes the influence of fluid factors on the permeability of porous media. The permeability of porous media is considered to be determined only by its own pore structure.

Experimental study on the secondary breakup properties of crushed coal through a dynamic porosity model based on Weibull distribution theory

Secondary breakup of the residual coal in goaf caused by periodic weighting changes its gradation, coal-oxygen contact area, stacking structure, etc. It cannot be ignored in studies of spontaneous combustion and compaction character of bulk coal. This paper developed a new dynamic porosity model employing the Weibull function based on the quantitative results of the secondary breakup phenomenon. A precise three-stages compaction process (particles self-organization and re-accumulation stage, secondary breakup stage, and simultaneous compression deformation stage) was observed and designated by this model. The competition mechanism among the deformation modes of coal particles during axial compaction was discussed. The main findings are as follows: (1) The formation mechanism of the stage characteristics in the compaction process for broken coal was actually a competition among the three deformation modes (secondary breakup, inter-particle self-organization, and inter-particle extrusion). (2) The proposed model allowed a finer division of the three stages of compaction from the perspective of the various deformation modes of coal particles. (3) The intensity of secondary breakup was weaker in the early and late stages of compaction and made no dominant contribution to deformation. A secondary breakup–dominated deformation stage was derived through comparing the proposed model with experimental data. (4) In the aforementioned deformation stage, the average relative error between the model’s predictions and the experimental data was 4.63%.

Impact of Sawmill Waste on SO2 Emissions from Co-firing with Lignite

ABSTRACT Results of experimental studies of joint pyrolysis processes of a fairly typical and widely used in Russia and Poland 3B grade lignite and wood (sawdust of pine wood) are provided. The results were performed in order to substantiate the previously formulated hypothesis about the mechanism of suppression of sulfur oxides in the combustion products of such mixed fuels. Conclusions on the mechanism of SOx suppression were made after comparing the analysis results of the elemental composition of the initial lignite, wood, and ash remaining after the total completion of the studied mixtures pyrolysis processes, as well as X-ray phase analysis of the ash composition. It was found that the proportion of calcium and aluminum sulfates is higher in the solid pyrolysis products of mixtures of crushed coal and wood compared to the ash of homogeneous coal. Practical significance of the performed studies is that the obtained results of the experiments allow to justify the possibility of using wood as a part of mixed fuels based on 3B grade lignite as an additive that significantly reduces the yield of sulfur oxides during combustion of such fuels in the furnaces of steam and hot water boilers. It has been experimentally established that during high-temperature decomposition of two-component fuels based on 3B lignite in a mixture with fine wood biomass, the effect of reduction of sulfur oxide concentration in gaseous pyrolysis products of such mixtures is obtained due to the formation of calcium and aluminum sulfates in the ash of mixed fuels as a result of chemical reactions between gaseous and solid pyrolysis products of lignite and wood with participation of water vapor.

Influence of mechanical grinding on characterization of nanopores of tectonically deformed coal: a comparative study between coal chunks and crushed coal

Accurately characterizing the pore structure of tectonically deformed coal (TDC) is an essential prerequisite for investigating the porosity change rules of coal during coal deformation. This paper aims to discuss the possibility of conducting gas adsorption on original coal chunks of TDCs instead of ground coal particles and to investigate the influence of mechanical grinding during coal preparation on pore structure characterization. First, we conducted N2 and CO2 adsorption tests on coal chunks and crushed coal (60 mesh particles) of primary structure coal and ductile TDCs (Ro, max = 0.93%~1.15%). Then, the influences of grinding coal into 60 mesh particles on the micro-mesopore structure of coal were investigated by contrastive analysis. N2 adsorption tests showed that the pore volume of the > 10 mesopores (especially the > 40 nm mesopores) significantly increased in crushed coal from that of coal chunks, and the observed increases in pore volume decreased progressively with the enhancement of ductile deformation. The difference in pore volume (by N2 adsorption), pore surface area, and surface fractal dimension (DFHH) of < 10 nm pores was insignificant, indicating that mechanical grinding hardly affected < 10 nm pores. During CO2 adsorption, incomplete equilibrium was observed in partial coal chunks of primary structure coal and weakly crumpled coal. After coal being ground into 60 mesh particles, incomplete equilibrium was effectively eliminated as grinding significantly shortened the distance between adsorbate molecules and micropores. Apart from that, there were no noticeable influences on the total pore surface area and micropore size distribution (by CO2 adsorption). Thus, during characterizing the pore structure of different types of TDCs (a micro- and mesoporous material), it is recommended to conduct N2 adsorption on the original state and conduct CO2 adsorption on 60 mesh particles if possible.

ИССЛЕДОВАНИЕ СОРБЦИОННЫХ ХАРАКТЕРИСТИК АКТИВИРОВАННЫХ УГЛЕЙ

The article presents the results of a comparison of the sorption characteristics for gold of crushed activated carbon of the foreign Haycarb brand, obtained from expensive raw materials - coconut shells, and crushed activated carbon of the domestic Shubarkol brand, obtained from relatively cheap raw materials - low-ash coking coal. The activated carbon Shubarkol crushed to a class of -3.6+1.0 mm, was produced in Kazakhstan from coking coal by Shubarkolkomir JSC. To test the crushed coal Shubarkol, industrial crushed coal Haycarb, made from coconut shells, was used as a reference sample. This coal is widely used in gold mining enterprises for the sorption of dissolved gold from cyanide solutions and pulps. For research, a productive solution of the process of heap leaching of gold from oxidized ore of one of the deposits of Kazakhstan was used with the composition, mg/L: gold 0.82; silver 0.44; copper 8.34; pH 11.05. Determination of the sorption characteristics of coals was carried out by the method of saturation with gold when changing solutions. The results of changes in the gold content in the mother solution, its extraction and saturation of coals with precious metal after each sorption cycle from the productive heap leaching solution using crushed coals of the Shubarkol and Haycarb brands are presented. It follows from the obtained data that Shubarkol activated carbon has similar sorption characteristics compared to Haycarb activated carbon. The working capacity for gold of Shubarkol coal was 2.28 kg/ton of sorbent, and of Haycarb coal - 2.57 kg/ton. Thus, crushed coal Shubarkol, obtained from relatively cheap raw materials, can be successfully used at industrial facilities instead of foreign sorbent.