Home – Home – Jornals – Journal of Mining Sciences 2024 number 4

This article commemorates a double jubilee date on February 8, 2024-the 300th anniversary of the Russian Academy of Sciences and the 80th anniversary of the Institute of Mining SB RAS. The author reviews the research and findings of the Institute’s scientists over the last 10-15 years in the area of mathematical modeling and numerical solution of present-day problems in geomechanics.

Wind transport of an air-borne dust cloud in the atmospheric boundary layer in the neighborhood area of a surface mine is analyzed by numerical solution of the Navier-Stokes equations in their full form for a compressible liquid and in a subsonic flow approximation. The dust source is a large-scale blast at a total mass of ~ 100 g of TNT at a depth of 250 m in the pitwall rock mass. The calculations take into account a portion of dust raised above ground surface by blasting. The size of the surface areas of air-borne dust concentrations above maximal allowable values is estimated. The relationship of this size and the wind direction-pitwall angle α is analyzed. The maximal distance between the pitwall and the area of dust concentration above MAV is 3 km. The exposure duration at the fixed point on ground surface is independent of the angle α and ranges from a few minutes at a distance of 500 m from the blast center to a dozen minutes at a distance of 3 km.

The author discusses the deformation kinematics method using the concept of displacement of material planes in a medium. Displacements of planes can be described by two vector fields of displacement or, by way of alternative, by one tensor field which is a field of relative displacement of planes. This is an asymmetric tensor, and its components are uncorrelated by Saint-Venant’s compatibility conditions. This approach recovers an “equality” between the kinematic-based and force-based descriptions of deformation in a medium. The adopted notion of stresses relates to the forces that affect planes inside a body, and the notion of deformation relates to the change of distances between pairs of points. The article gives a case-study of modeling an initially isotropic geomedium using this approach.

Experimental research determined the concentration zones of seismic events and their sources in operating Taimyr Mine. The features of formation and spreading of these zones are assessed. The influence of mined-out void volume on total energy of seismic events before and after flooding and dewatering of mines is analyzed, which allows predicting the level of seismic hazard during further mining.

The ore drawing procedure of the synchronous filling shrinkage mining method is simulated using PFC software. Isolation layer thickness A, isolation layer interface friction factor B , ore particle friction factor C, particle radius D and wall friction factor E are chosen as the five influencing factors of the orthogonal test, along with the characteristics of the orthogonal test and force chain parameters. The findings demonstrate that the primary and secondary order of each factor impact on the orthogonal test index is D>C>A>E>B. The best test configuration was A₁ B₂ C₃ D₃ E₃, with the relevant factors being thickness 0.003 m, isolation layer interface friction factor 0.5, particle friction factor 0.8, particle radius 0.008 m and wall friction factor 0.8.

The article describes inertial impact fracture of geomaterials using a rotary hammer drill. The capabilities of the tool in underground large-hole drilling are discussed. The authors present the procedure and results of the lab-scale testing of influence exerted by different combinations of rotational and linear path velocities of the rotary hammer drill on the strength of current taken by working tools and on the shock vibration velocity of supporting members of the rotary hammer drill. The rational ranges of these velocities, such as the process of fracture runs at the least energy input and minimum impact on the working tools, are determined.

The experimental research assessed the influence exerted by the parameters of cutting process and cutting tool on the loads in cutting hard inclusions in rocks. It is found the in central cutting of hard inclusions, the maximal loads on a cutting pick depend on the width and depth of a cut, and on the cutting pattern, and are independent of the cutting velocity. The increase in the width of the cutting point of a cutting pick contributes to an increase in the peak and average-peak forces of cutting and feed, while the lateral loads in cutting hard inclusions by cutting picks with a flat face depend only on the depth of cut. The peak feed forces essentially depend on the shape of the cutting point of a cutting pick, and the cutting force depend on the angle of cutting. The decrease in the wedge angle of the face of a cutting pick reduces the peak forces of cutting and feed, while the lateral loads increase.

To increase the efficiency of gas extraction drilling in coal seams, screw drilling tools used in petroleum-related operations were introduced instead of common bottom-hole combination drilling tools. According to the Box-Behnken experimental design principle, the significance of three main construction factors on the drilling efficiency is: the flow rate > pump pressure > feed force. The optimized drilling parameters were used to conduct a field test in Wangzhuang coal mine of Shanxi Lu’an Group. The results showed that the drilling efficiency of screw drilling increased by 39.08% and the drilling slag discharge increased by 48.28% compared with the conventional rotary drilling technique, which significantly improved the construction efficiency of coal seam drilling and is expected to reduce the gas treatment cycle and cost of coal seams to a significant extent.

The authors have revealed and compared the internal and external parameters that form a multi-element loop system (dimension chain) of a roller cone drill bit. The article presents procedures for the probability calculation of a dimension chain of the tool dimeter, calculation of the tool diameter error because of the rotation of the cone drill bit on the bit leg, and for the calculation of eccentricity error of gage cones relative to the axis of the fitting thread for three- and four-cone drill bits. It is recommended to revise the values of dimensional tolerance for roller cone drill bits and to amend related normative and technical documentation.

The article reports the research of composition and properties of loparite concentration tailings at the Umbozero plant closed in 1999. During the research, samples of tailings were taken in the surface layer and at depth, using the method of cutting ring. The geological and engineering properties of the tailings were investigated, and the sizing, chemical, X-ray phase and radionuclide analyses were performed. The research revealed heterogeneity in material constitution and properties of the test tailings. The mineral composition of the tailings is dominated by nepheline, and by K and Na feldspars. Loparite is detected by the X-ray phase analysis at one of the four test sites of the tailings pond, and its content increases in the fine fraction. The analysis of radionuclides shows the presence of radium and thorium in the test concentration tailings.

The research focuses on usability of tailings from the Talmovskie Peski and Ursk dumps in the Kemerovo Region as a manmade source of barite after suitable recovery and processing. Mineralogical, geochemical and typomorphic characteristics of barite are assessed from morphology, mineral associations, content and grain size distribution. The technological studies are accomplished, and barite concentrates are obtained from the test tailings by gravity separation and flotation. The concentrates are assessed with respect to barite content with a view to using the concentrates as a weighting material as per the USSR State Standard GOST 4682-84. The barite recovery potential of tailings from the Talmovskie Peski and Ursk dumps is evaluated.

The authors analyze convection-induced stratification of air flows in an inclined drift with an intense heat emission source. The research methodology included 3D numerical modeling of nonstationary aero-thermodynamic processes in an inclined drift and in an adjoint horizontal drift. The article describes three possible scenarios of convection-induced air flow stratification in an inclined drift depending on heat emission intensity. The dependence of the critical heat rate of the heating source on the initial depression and incline of the drift is determined. The pressure difference-mass air flow relationship in the inclined drift is analyzed at different heat emission intensities using the 3D numerical model and a 1D network model. Description of underground mine fires using 1D models requires empirical relationships of air drag, average air density and air flow rate.

The articles describes the studies of influence exerted by operation of a jet fan installed on a shearer on air drag and on methane and coal dust concentrations in a longwall. The investigation used ANSYS Fluent and field data from coal mines in Kuzbass. The object of study was dust and gas/air mixtures in extra-long panels with a length of 400 m and at mineable coal seam thickness of 2.4 and 3.7 m. It is found that jet fans can decrease air drag in such longwalls by 35%, which enables decreasing the air feed in the longwall by 24% without increasing the main fan capacity. The air flow generated by a jet fan eliminates dead methane-air zones nearby an operating shearer and decreases coal dust concentration at work places of shearer’s operators by 13.8-36.7%.

The authors address a relevant problem connected with digital transformation of the mining industry toward import substitution and creation of a barrierless technology to operate digital data and models of objects of a mining technology with a view to solving tasks in geology, surveying and engineering. An important component of a barrierless technology is a single virtual digital space for the database translation when using program products based on different object models. Such technology is implementable through formation of a digital platform containing a basic function to operate object models in digital space and API-functions to integrate the created tools into this digital space. The requirements of the digital platform are to the largest degree met by the program products of mining and geological information systems. In the digital space of such systems, 3D modeling is performed and basic mining and geological problems are solved. The article formulates the main functionality standards of such digital platform and describes the current situation in creation of the platform using the mining and geological information system (MGIS) MINEFRAME at the Mining Institute, KSC RAS, and at MINEFRAME Laboratory LLC.

The article presents an analysis procedure for remote sensing imagery for monitoring ground surface objects. The studies on development of an algorithm for identifying mining waste disposal facilities on ground surface are described. The source data were Sentinel-2 and Landsat 5-8 images of the southern area in the Russian Far East. Using Earth Engine platform, the vegetation index is calculated for each pixel using the function of normal distance, and the test area is generated using a standard tool. Pixels were converted to square units using the reduce() method. The proposed procedure is of current interest in monitoring various objects (tailings ponds, surface mines, waste dumps, etc.) at different stages of development.

It is found that zeolite-bearing rocks from the Khola deposit can be dressed toward manufacture of high-quality sorbents to remove impurities from waste and recirculated water, and the relevant processing circuit is proposed. The mineral composition of the Khola zeolite-bearing rocks is described, and their electromagnetic and electrostatic separation results are reported. The layout of a continuous adsorption plant using zeolite-bearing rocks is developed. The sorption capacity of original and dressed zeolite-bearing rocks from the Khola deposit is tested in model solutions. The test data of arsenic adsorption using zeolite-bearing rocks are presented. The efficiency of zeolite-bearing rocks in removal of arsenic, fluorine, zinc, lead, nickel and chrome from a model solution of waste water is evaluated and compared. The prospects of using zeolite-bearing rocks in mine waste water treatment and in removal of impurities is assessed. The resultant purification boasts high-value results which ensure the required quality of waste water.