Home – Home – Jornals – Journal of Mining Sciences 2017 number 1

The generalized observations over hypocenters of the strongest mining-induced events have shown that this type of deformation occurs as movement along the existing faults. From the experimental evidence, transition of a section of a fault to meta-stable state goes with the decrease of its dynamic shearing rigidity. The alteration of the mechanical properties starts long before macroscopic movement of the fault surfaces is recorded. This effect is detectable using instruments and can be used as a foundation for a new approach to monitoring of induced earthquakes.

The authors use mathematical model of structurally inhomogeneous rocks to describe the property of rocks to accumulate and release potential elastic energy. The finite element algorithm and bundled software are developed to solve plane boundary-value geomechanical problems. The article presents calculations of deformation of self-stress rock specimens. It is shown that the deformation curve depends both on the elastoplastic properties of the specimens and on their natural self-balanced stresses. Depending on sign, the stresses can either increase or decrease the limit load under which the specimens fail.

This paper presents one strain gradient model of zonal disintegration of rock mass near deep level tunnel. The governing equations and boundary conditions of the model are established. Numerical methods (quasi-Newton method and shooting method) are adopted to solve the obtained fourth-order equilibrium equations with higher order boundary conditions in terms of displacement. The stress field in elastic and plastic zones is obtained. The effects of model parameters on stresses distribution in surrounding the tunnel rock mass are examined. The necessary conditions for the formation of zonal disintegration are elucidated.

The authors propose methods and means to monitor deformation and subsidence of ore crown under mining of open-pit bottom reserves by room-and-pillar system with solidifying backfill in Mir Mine, Alrosa. The article describes layout and data of geomechanical monitoring. The mechanism of ore subsidence at the lower boundary of the safety pillar is determined.

The calculations of stress state and failure of rock mass in the vicinity of longwall in a coal bed with the high gas content in Polysaevskaya Mine, SUEK-Kuzbass, are described. The effect of the mining depth and coalbed gas pressure on the geomechanical situation in the longwall is illustrated. The authors discuss scenarios of directed crack formation in front of the longwall.

Roughness of the main crack surface is an assessment criterion for stress state of geomaterials for the quantitative connection has been found between the crack roughness and stress state of geomaterials. Roughness reduces with an increase in the maximum normal stresses in the zone of failure (the area of the maximum shear stresses). Based on this regularity, the method has been developed to assess stresses using the crack surface roughness in geomaterials.

Numerous abandoned workings, mostly tunnel ones, are present in post shallow mining areas. With time, timber roof supports have been degraded and lost their bearing capacity, while excavations lost stability. The loss of stability of an excavation and its failure is often a cause of sinkholes formation at the surface, sometimes even many years after mining activities were discontinued. Such instances pose a threat to buildings and their users-to public safety. A prediction saying that the probability of sinkhole formation is greater than 0 and smaller than 1 is ambiguous and does not allow making right decisions about the use of land. Therefore, it seems advisable to provide a simple algorithm that would allow to deterministically calculate whether a sinkhole is to be formed or not. This paper presents a method of predicting the probability of sinkhole formation based on Salustowicz’s theory as well as its practical application using a computer program. It should be borne in mind, however, that there are other factors influencing the probability of sinkholes formation, which cannot be taken into account in a mathematical model. These factors include non-mining phenomena, such as suffosion, load imposed on land, vibrations caused by movement of heavy-duty vehicles and other.

Under numerical investigation is propagation of surface pendulum waves in 3D block medium. The medium is modeled by 3D lattice of masses connected with elastic spring connections and viscous dampers. The surface pin vertical pulsed loading is considered. The displacements and velocities of the surface masses are calculated. The numerical results obtained for the block medium are compared with the similar data on elastic medium and in situ experiments carried out by other researchers.

The authors give an assessment of the effect exerted by blasting on the intensity of geodynamic and seismic events. The key regularities of distribution of shocks under blasting of rock blocks are found. The scope of the experimental research embraces determination of seismic velocities on the ground surface in mining area in Gornaya Shoria.

The article reports basic design parameters of open pit mines of Alrosa, as well as criteria and factors that govern the choice of production capacity of an open pit diamond mine under conditions of permafrost. The analytical relations and tables to calculate open pit mine life are presented, and the influence of the rate of the downward advance of an open pit mine on its capacity is demonstrated. The authors formulate key provisions for a paragraph of the national standard of RF enabling systematization of approaches to optimization of open diamond mining parameters.

Geological characteristics of ore and enclosing rock mass at Orlov deposit, including Severnoe body of Novaya ore chute, are given. The ore is extracted by underground method, with slicing and room-and-pillar, and sublevel caving. The technology of backfill preparation based on cement-slag binder is evaluated. After lab experimentation, the rational compositions of the backfill have been developed for Orlov Mine. It is found that activity of granular blast-furnace slag is conditioned by chemical composition, structure and, to a wide extent, by grinding fineness (specific surface). The technical-and-economic assessment of the new technology of backfill preparation has been carried out.

The authors propose a promising approach to reduction of the environmental impact of open pit mineral mining-robotic automation of geotechnologies. The objectives, techniques and advantages of introduction of industrial robots are discussed. The analysis of development and improvement of geotechnical system reveals factors that limit application of mechanized, automated and robotic equipment. The structural elements of geotechnical system using mechanized and robotic mining and transportation machines are compared.

The article describes regularities of mass transfer in filled-up and washed-in piling of mineral mining waste. The criteria and hierarchy are determined to classify structures of waste piles. The structures of waste piles in Kuzbass are classified, and the diversity of one-component and compound structures of piles is presented schematically. It is shown how the determined regularities of mass transfer influence formation of fractional structures of mine waste piles, and on their physical and processing characteristics.

Design of an air drill hammer with the smooth adjustment of the percussion frequency at the constant blow energy is considered. The proposed and analyzed versions of air distribution system are based on using a mechanically closing elastic valve. The test data on experimental prototypes of the air drill hammer with the external distributing elements that set blow frequency are presented. The frequency adjustment ranges are determined.

Aimed at improving efficiency of non-explosive vibroseis method, the new concept of using a solenoid percussive drive enables essential increase in useful mechanical work with the limited external diameter. The results of the finite element modeling of magnetic field in FEMM are reported. The authors have found the force and energy characteristics of the drive and the prospects for its application in a casing with the external diameter limited to 120 mm.

The structural and chemical surface transformation of basic kimberlite-forming minerals (calcite, olivine, serpentine) under the contact with natural and waste mineralized water and products of electrochemical treatment of the water are studied using X-ray photoelectronic spectroscopy, scanning electron microscopy and X-ray spectral micro-analysis, and atomic force microscopy. It is found that contact of kimberlite extract and recycling water induces chemical modification of calcite surface, which consists in adsorption of hydrocarbon impurities, and chlorine- and silica-bearing compounds, majority of which are removed during interaction with the product of electrochemical treatment of recycling water. The change in the structural and chemical surface properties of rock-forming silicates, aside from adsorption-desorption of organic compound, is also connected with the distortion of nano-size layer structure after leaching of Mg, Fe and Si, and with the carbonatization of the surface.

The numerical modeling provides a holist picture of mechanical treatment and activation of substances in disintegrator. The authors calculate kinematic and dynamic characteristics of elastic and inelastic collisions in terms of halite, quartz and sulfur particles and disintegrator fingers. The recommendations on selecting optimal treatment conditions for natural minerals and waste material in order to dissociate mineral concretions and for selective activation of minerals are given. The research findings can partly be used for other types of percussion disintegrating devices, in particular, jet mills.

The article focuses on concentrating of nickel from lean solutions of leaching of oxidized nickel ore. The proposed block diagram of process flow chart for such solutions includes hydrolytic removal of admixed iron and aluminium and precipitation of nickel concentrate by calcinated magnesia. The as a result, nickel content of the concentrate is 26-26% at the recovery of 95-97%. The issues of decontamination and recycling of the solutions are solved.

The article describes mineralogical and processing properties of ferruginous quartzite from Kimkan deposit. Essential nonuniformity of the composition and properties of the major metallic mineral-magnetite-should be accounted for when processes and, particularly, when selecting pretreatment method.

The authors describe studies into dressability of mill tailings from tailings pond of processing plant of Yaroslavskaya Mining Company. It is found that the mill tailings contain 14.92% of CaF₂, 13.16% of CaCO₃ and 0.49% of Zn. The use of new compositions of modifies in flotation of fluorite allows production of standard grade concentrates with the CaF₂ content of 93.19-95.54% at the recovery of 52.75-30.15%. Zinc recovery in the concentrate is 38.84% at the yield of 42.11%.

The environment protection and dust control on washed-in waste piles is complicated by the continuous replenishment of tailings and, consequently, formation of new dusting layer on the pile surface. This problem can be solved using aerosol guns-fog-projection devices within the dust suppression system. The authors propose to place the aerosol dust suppression system on a platform-car moving along a tailings dump. This allows automating dust control and increasing volume of transported water. Grain-size composition of dust at tailing dumps of Kovdor Mining and Processing Plant is determined. From the laboratory experiments, it is found how intensity of dust transfer abates dust suppression. The experimental findings make it possible to calculate the required number of jets for an aerosol gun.

Mining and processing industry forms mining landscape. Reclamation of mined-out areas is an efficient way of the environment protection in mining regions. It is rational to make mining-disturbed lands suitable for further use by taking mineral mining and processing waste. Justification of technology of placing waste in the mined-out void of Vostochny open pit of Magnitogorsk Metallurgical Plant at Magnitnaya Mountain (Chelyabinsk Region) is based on the analysis of hydrodynamic and hydrochemical history of the project, laboratory studies into interaction of backfills with quarry water and prediction modeling of change of conditions in the course of backfilling the open pit by means of modeling hydro-geomigration.

Geophysical methods of detecting places of spontaneous heating in mined-out voids in gently dipping and inclined coal bed in Kuzbass mines are reviewed. The emphasis is laid on the method of equatorial dipole sounding used to determined temperature of coal in the place of spontaneous heating in Olzherasskaya Novaya Mine. The cooling time of the coal and rock nest down to the temperature of surrounding rock mass is estimated, and the self-heating seat suppression actions are proposed.

Samples of rocks with different physico-mechanical properties (three kinds of granite, marble and quartzite) were subjected to destruction by impacts. Fractoluminescence was recorded on the damaged surface, and amplitudes and frequencies of series of light pulses were determined. On all test samples, initiation of inter-grain cracks was observed. Defects on the surface of grains in granite samples had two typical sizes conformable with defects in quartz and spar, while uniform content minerals (marble and quartzite) features unimodal distribution of sizes of defects on the surface of grains.