Home – Home – Jornals – Journal of Mining Sciences 2013 number 4

The article gives the experimental proof of effective use of the kinematic criterion χ, derived by Oparin for “apparent” velocities of pendulum waves based on deterministic description of seismic energy release in the Norilsk mine fields, for assessment of stresses and strains in coal beds in terms of the Polysaevskaya Mine, Kuzbass.

Based on numerical modeling of stress–strain state of rocks and the in situ deformation monitoring of rocks mass surrounding underground excavations, the authors determine limit criteria of geomechanical stability of mine structural elements in terms of the Aikhal Mine where mining has been transferred under the worked-out open pit bottom. Using the determined criteria, the stress–strain state and subsidence of the crown pillar are assessed, considering current stage of the water table in the open pit. The article gives predictive estimate of the change in the stress–strain state and subsidence of the crown pillar upon the water level raising.

The regular patterns of initiation and show of acoustic emission memory effect in a composite are experimentally obtained using cloth laminate. The authors illustrate capacity of cloth laminate as an absolute sensitive stress-to-acoustic emission converter. The designed and tested downhole sensor enclosing this converter provides indication of incremental stress excess over pre-assigned critical limit.

The article reports the integrated assessment of natural stresses in rock mass in the Nurkazgan Mine. The visual observation of underground excavations and instrumental measurements of effective stresses denote the hydrostatic stress state within the studied minefield

The issues of physico-mechanical properties of ore and rocks, measurement of displacements in rock mass around underground excavations, stability of the excavations, selection of types and parameters of supports are studied in terms of the Yakovlevsky iron ore deposit

Out of aspects of modeling mathematically deformation of rock specimens, the article analyzes soft and rigid loading. The authors formulate an inverse problem on identification of mechanical properties, boundary conditions and geometry of weak areas using overspecified conditions using data on measured displacements and acoustic-electromagnetic emission that characterizes rock failure under loading.

Based on the review of the strongest mining-induced rockbursts with the same seismic characteristics recorded in underground mines in Russia, the author compares the events based on their energy parameters. It is shown that the mining-induced seismic events on the Kola Peninsula are still the strongest events.

The article presents and discusses a quasi-brittle rock failure model, analytical expressions constructed for limit stresses using necessary and sufficient criteria of structured rock failure, normal tensile stresses in rock mass with fracture, quasi-brittle failure diagram constructed using approximation of two-section kinked stress–strain curves obtained in coal under tension, and critical stress estimates.

Mining complexes can contain multiple mines operating simultaneously along with multiple processing streams, stockpiles and products. Stochastic optimization methods developed to date generateonly local optimal solutions in the sense that they do not consider the entire mining complex. This paper presents an extension of a multi-stage method used for generating long-term risk-based mine production schedules, to operations with multiple rock types and processing streams. The developed method uses a simulated annealing based algorithm during the optimization stage, seeking to minimize deviations from production targets for waste and different ore processing streams. The proposed approach is applied at Escondida Norte copper deposit, Chile, in which sulphide, oxide, mixed and waste materials are present with milling, bio-leaching and acid-leaching being the available processing streams. The stochastic schedule generates expected deviations from mill and waste production targets smaller than 5%, which avoid indirect costs associated to idle capacities. A schedule generated conventionally exhibits expected deviations of the order of 20%.

The authors report experimental research and in situ study of oxidation and ignition factors in opencast mining of fire-hazardous ore. The article makes recommendations on spontaneously flammable ore extraction and storage as well as prevention of endogenous fires and fire protection in sulfide ore stockpiles.

The article describes experimental destruction of kimberlite ore and impact crushers and bases the use of the combined impact crusher DKD-300 at one of the crushing stages within the dry concentration scheme at the Zarnitsa kimberlite pipe projectre.

The authors have designed a stand with a pendulum drop hammer to model the hammer head–impact tool–rock mass interaction. The rock mass is simulated with an adjustable gas–liquid dampener, metal plate and marble block. The comparison analysis includes measured impact pulses in the hammer head and the impact tool, and the influence of the hammer head velocity recovery factors on interaction of the hammer head and impact tool with the dampener and rock block.

The article describes the design of the unique monitoring system for technical state of transportation vehicles and production machines used in mining and construction. The introduction of the system will cut down expenditures due to sudden machine failure, and will increase efficiency and capacity of machines.

The article presents experimental research of the influence exerted by electrochemical polarization on electrode potential, phase composition of surface formations, adsorption of collector and floatability of basic sulfides of gold-bearing ore. It is shown that phase composition of surface formations under different polarization modes affects adsorption of collectors and floatability of minerals.

Based on the nonmechanical energy deposition tests aimed at intensification of destruction and processing of rebellious minerals, it is found that mineral treatment by accelerated electron flow enhances technological performance of mineral processes and is cost-effective: metal extraction grows by 27% and processing performance is enhanced 2.2 times.

In terms of galena, the authors specify construction principles for kinetic “ion” modeling of surface layer composition on grains of sulfide minerals of nonferrous heavy metals during flotation. The physical sense of the models consists in connection of parameters of ions within liquid phase of flotation slurry with relative fractions of mineral grain surface. Commercial tests proved the theoretical concept on formation of sorptive layer of sulfhydryl collectors on the surface of sulfide mineral grains under flotation conditions.

It is possible to forecast efficiency of mechanical activation of loparite concentrate to make it subsequent nitric-acid leaching fast using the X-ray crystal analysis data. It is found that the type of accumulated energy influences the energy of activation and reactivity of loparite. The authors suggest an expression to estimate extraction of rare earth elements in nitric-acid solution versus energy of structural changes caused in loparite by mechanical activation and leaching.

The article focuses on the current situation and problems of the mineral and raw materials base in Russian Federation.