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The methods of increasing energy and operation parameters of a pneumatic hammer with an air distribution valve are reviewed. The algorithm of restructuring impact capacity of a pneumatic hammer with an elastic ring valve in the back stroke chamber of the hammer piston is proposed: it is suggested to use a feed source with an increased-pressure energy carrier. The algorithm was employed in designing and manufacturing a prototype model of the hammer. The actual operation factors of the prototype model are determined on a lab-scale bench tester: impact energy, impact frequency, energy carrier flow rate. After processing of indicator pressure charts, compressed air flow rate per unit energy output is assessed.

The article describes the experimental results of using synthetic sorbents made of hypercrosslinked polystyrene copolymers with divinylbenzene and vinylpyridine for recovery and separation of valuable components (Zr, Σ REE) from pregnant solutions of nitric acid leach of eudialyte. It is found that at the stage of Zr and Σ REE recovery from pregnant solutions, the most effective are resin Puromet MTS 9500 and bifunctional strongly acidic cation exchanger Purolite C160. Regarding Puromet MTS 9500, a flowsheet of step-by-step gradient elution of the sorbent saturated with valuable component is proposed. The flowsheet enables the outlet solutions of Zr and Σ REE at the recovery of 97.7 and 81.1%, respectively. Efficient separation of REE to subgroups is reached with resin VP-3AP.

The authors justify theoretically and experimentally the promising modification methods for saponite-pillaring and thermal treatment. These methods ensure production of sorbents with high capacity of cation exchange relative to cations of rare earth elements. The mechanism of pillaring and thermal treatment of saponite-bearing products at the temperature of 625 ⁰C includes expansion of the mineral layers, generation of additional acid and oxidation-reduction centers (pillaring), as well as restructuring with formation of meta stable phases (thermal treatment). Optimization of application parameters of the sorbent (pH, sorbent-to-solution ratio) ensures efficient recovery of some REE from pregnant solutions of eudialyte concentrate leaching at the adsorption capacity up to 18.8 mg/g.

The authors investigate a new reagent-modified water-soluble polymer of polyvinyl caprolactam (PVCL)-as a collector in flotation of gold-bearing sulfide ore. Modified PVCL is obtained by solid-phase modification of poly(N-vinyl caprolactam) by thiourea. The electron scan and laser microscopy identified adsorption of PVCL at gold grains applied artificially to the surface of polished sections of pyrite. It is found that PVCL facilitates selective aggregation of gold-bearing minerals from fine slime, and more than 99% of gold goes from fine slime to sand at the content of 3.54 g/t. The use of PVCL together with butyl potassium xanthate (PVCL 30 g/t, BPX 200 g/t) in flotation of finely ground gold-bearing ore from the Olimpiada deposit improved the quality of the concentrate: gold content increased from 19.9 to 29.5 g/t and gold recovery increased from 81 to 95%. The joint application of modified PVCL and BPX results in the gold recovery higher by 14%, concentrate quality improved 1.5 times and in the gold content of tailings reduced to 0.15 g/t.

The authors validate the use of magnetic hydrocycloning in extraction of weak magnetic-responsive slime particles from finely dispersed magnetic suspension. Efficiency of a lab-scale magnetic hydrocyclone with regular electromagnetic system of copper wires on the cone, without superconductive materials involved, in extraction of magnetite particles -20 µm in size is described. The test results prove recoverability of hematite and other weakly magnetic minerals in magnetic hydrocycloning at the required flux density of 2-10 T created by a superconductive magnetic system under conditions of cooling at the liquid nitrogen temperature, which minimizes energy intake of magnetic separation. The use of the superconductive magnetic system and high-temperature materials on the hydrocyclone cone enables efficient extraction of weakly magnetic particles, for instance, red mud -10 µm in size.

The article describes a solution to the problem connected with the earlier proposed method of remote appraisal of hydrocarbon reservoirs by passive seismic. It is shown that a linearity only appears in a certain frequency range and fails fast when the latter expands. It is found that the linearity is connected with the non-Gaussian behavior of seismic noise in the isolated specific frequency range. The author proposes a method to asses an informative frequency range using experimental data, polyspectral analysis and surrogate time series.

The geomechanical monitoring system of ground surface in the area of the Atasu Iron Mine lease is described. The actual undermined ground surface is examined using drone photogravimetry. The sources of ground deformation are determined from independent measurements within a created temporal reference test site aligned with GNSS coordinates. High-precision geometric levelling is accomplished using metal benchmarks set as three levelling lines along and across the strike of ore bodies with a view to revealing rock mass movements in the course of underground mining.

Re-usability of wastewater from open pit coal mines and surface flows is discussed with regard to the adopted water circulation cycles. The analysis of process flow charts of open pit coal mining and water use made it possible to identify the main trends of wastewater application and volume reduction. A flowsheet of integrated treatment and distribution of wastewater in open pit mines is developed. It is shown that efficient management of intramine water consumption and expansion of cooperation with wastewater consumers can allow high-rate recycling of industrial wastewater. The proposed activities can help reduce environmental pressure in the coal mining areas, and decrease amount of wastewater which need advanced treatment down to maximum allowable concentration of harmful agents in fishery water bodies.

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.