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Kazakov S.V.,REC Mekhanobr Tekhnika | Shishkin E.V.,National Mining University
Obogashchenie Rud | Year: 2015

Taking into consideration severization of requirements to vibratory machines with respect to throughput rate, reliability and compact design, their improvement becomes increasingly important and difficult task. One of the promising ways to improve vibratory machines is changeover from one-mass and two-mass machines to machines based on three-mass system. A vibratory cone crusher based on two-mass system is distinguished by a number of advantages in comparison with one-mass machines. With that, it suffers from one significant deficiency: during operation impact loads are bound to recur, producing an extremely detrimental effect upon machine's elements that are non-functioning directly in impact, in particular, on vibration exciters and their bearings. Creation of vibro-impact crusher based on three-mass system will permit to considerably decrease dynamic loads on bearings of vibration exciters' rotors owing to so-termed vibration damping effect, that may almost completely isolate crusher's foundation from unbalanced dynamic forces. In order to improve mechanical and performance parameters of vibratory cone crusher, a design model of machine based on three-mass system is proposed. Crusher's body and cone vertical-plane oscillations are generated by a pair of inertial vibration exciters, installed on vibrating platform, which, in turn is supported on immovable foundation through vibration isolators of low stiffness. Differential equations of crusher's motion, describing vertical-axis free-oscillation modes of crusher's body and cone, as well as vibrating platform, are derived. Solution of these equations permitted to establish the expressions for machine's natural frequencies and free-oscillation modes, analysis of which provides for assessment of its forced oscillation mode, specifically: to determine resonance frequencies and ratios of body and cone oscillation amplitudes to that of vibrating platform.

Shishkin E.V.,National Mining University | Kazakov S.V.,REC Mekhanobr Tekhnika
Obogashchenie Rud | Year: 2015

Vibratory cone crusher, developed by the Research-and-Production Group «Mekhanobr-Tekhnika» for disintegration of different hard materials, is characterized by such advantages as a high reduction ratio and low content of small size fractions in crushed product. The article considers the dynamics of vibratory cone crusher that comprises body with inner crushing cone, attached to it by means of a special resilient member. Cone possesses only single translational degree-of-freedom relative to body, and with that, crusher is driven from a pair of self-synchronizing vibration exciters, attached to machine body symmetrically about its vertical axis. In addition to that, crusher's dynamic model is symmetrical and balanced, with body and cone performing in operating regime purely vertical opposite-phase oscillations of the same frequency. Besides, viscous interaction force is assumed to act between body and cone with coefficient β. The value of this coefficient may be selected through experimental determination of energy losses over crusher's synchronous oscillations period. In this case, the dynamic model under consideration may be also tentatively used for analysis of vibro-impact operating mode. In order to verify the results of the theoretical studies of vibratory cone crusher's dynamics, the experimental studies were performed, and the theoretical results agreed with the experimental ones with sufficient degree of accuracy. In addition to that, on the basis of the performed studies a conclusion may be drawn, that in the system in question a regime is possible, when body and cone perform synchronous opposite-phase oscillations (crusher's operating mode). A possibility for realization of required regime of body and cone oscillations will considerably improve operational parameters of crushers, designed according to the described configuration.

Dmitriev S.V.,REC Mekhanobr tekhnika | Kotova E.L.,National Mineral Resources University | Mezeniv A.O.,REC Mekhanobr tekhnika
Obogashchenie Rud | Year: 2016

The results of the Oshurkovskoye deposit apatite ore material composition study are presented. The deposit is located in a special ecological requirements zone in Transbaikalia. Development of a dry processing technology based on vibrational fluidization effect has been considered for the ore in question. Due to the fact that the deposit is located in a dry zone, the conventional flotation method application is not possible because of the special environmental status of the area. For this reason, the developed flow sheet for the apatite ore processing is based on dry methods of beneficiation combined with vibrational effects. The mineralogical-petrographic studies have been performed, including diagnosis of special features of the mineral composition, quantitative analysis of the ore apatite grade, apatite intergrowth with other minerals has been assessed with respect to aggregates composition, character of interfaces and types of intergrowth. The Oshurkovskoye deposit ore material composition study showed that all studied specimens were represented by diorite and syenite-diorite ores with fairly homogeneous mineral composition and rather low - approximately 4 % - P2O5 content. Grains of main ore and barren minerals, including apatite, are 0.1-0.2 mm and over in size, which is contributory to dry physical methods of beneficiation. On the basis of the ore material composition, a process flow diagram has been developed for dry beneficiation of the ore in question, including electromagnetic separation in fluidized state, permitting to produce apatite rougher concentrate with P2O5 grade of 16.5 %, suitable for subsequent flotation upgrading stage, providing for saleable quality product.

Shishkin Y.V.,National Mineral Resources University | Kazakov S.V.,REC Mekhanobr Tekhnika
Obogashchenie Rud | Year: 2014

Vibratory cone crushers are characterized by such advantages as a high reduction ratio and low content of small size fractions in crushed product. The article describes a theoretical substantiation for the choice of operating synchronous frequency, important in design of vibratory cone crushers. The crusher comprises softly cushioned body with crushing cone, attached to it by means of a special resilient member. With that, cone possesses only single translational degree-of-freedom relative to body. Crusher is driven from a pair of self-synchronizing vibration exciters, attached to machine body symmetrically about its vertical axis. In addition to that, with synchronously in-phase mode, body and cone shall perform purely vertical opposite-phase oscillations. The crusher impactless mode of forced oscillations was studied on the basis of six-degree-of-freedom dynamic model. Vibratory crusher body and cone purely forced oscillations relationships were revealed, and their amplitude-frequency and phase-frequency characteristics were analyzed. Presence of body antiresonance was established in coincidence of disturbing frequency with cone partial frequency. It is shown, that if disturbing frequency exceeds given partial frequency of cone, body and cone forced oscillations are opposite-phase in character, necessary for crusher adjustment to operating mode.

Abramovich V.L.,Russian Academy of Sciences | Sergeevich I.K.,REC Mekhanobr Tekhnika | Yevgeniyevich M.A.,HORIS Ltd
Obogashchenie Rud | Year: 2013

Screening process efficiency directly affects power consumption in open and especially locked crushing circuits, since precision in size classification determines total load on energy-intensive crushing equipment. Correct calculation and choice of adjustable parameters in screening and screen design provide for real power savings in processing of all types of raw materials, and, in addition to that, ensure commercial quality of end products in processing of industrial minerals and coal. Granular materials' sieve classification process also plays an important role in wastes processing, as well as in other branches of industry. Notwithstanding the decades-long history of these technologies application, a bal- anced engineering model of screening process has not been developed yet. This article presents a model, developed with a view to bridging of a gap between quantitative and empirical approaches: the former being too slow, and the latter - insufficiently precise. The aim is achieved through improvement and adaptation of a number of analytical methods with respect to numerical modeling. Additionally, the knowledge of vibratory segregation process in material layer was extended. The proposed method permits to model vibratory screening process with a high precision and without long-duration adjustment, calibration and preliminary experimental preparation, and, with that, is suitable for consideration of a wide model range of apparatuses. On the basis of the proposed method, a computer software program with friendly user interface was developed, enabling designers to assess performance of an apparatus under development by input parameters.

Blekhman I.I.,Russian Academy of Sciences | Blekhman L.I.,Russian Academy of Sciences | Vaisberg L.A.,REC Mekhanobr tekhnika | Ivanov K.S.,Russian Academy of Sciences
Vibroengineering Procedia | Year: 2014

This talk presents two approaches for modeling of the vibration screening process. The first approach is analytical. It models the screening process as a diffusion of undersize fraction taking into account the special term for vibration separation (the Brazil nut effect). The talk provides a solution of the corresponding partial differential equation. The solution in turn allows estimation of the screening performance dependence on both deterministic and stochastic factors as well as evaluation of the factors dominance conditions. The talk presents simple evaluation formulae for the screening process performance. The second approach is based on a simulation model. The model deals with monolayer dynamics. Embodying traditional concepts of vibration transportation, the approach introduces some novel techniques of evaluation of the effect of the granular particles shape. Taking into account the particle shape factor may significantly improve the modeling precision for nonspherical particles. © JVE INTERNATIONAL LTD.

Kazakov S.V.,REC Mekhanobr Tekhnika | Shishkin E.V.,Saint Petersburg Mining University
Obogashchenie Rud | Year: 2016

A symmetrical flat dynamic design of vibratory cone crusher based on three-mass system is considered. It includes carrying body (vibrating platform) with two working organs (body and cone). Crusher's body and cone are linked with each other through elastic system with coefficient of stiffness Cp, cone and vibrating platform - Through elastic system with coefficient of stiffness n. Vibrating platform is supported by immovable foundation via resilient shock absorbers of negligible stiffness. Oscillations in the system under consideration are excited by a pair of self-synchronizing inertial vibration exciters, installed not on one of the working organs, as in conventional dynamic design of vibratory cone crusher, but on carrying body. The laws of pure forced oscillations of working organs and carrying body were revealed, and their amplitudefrequency characteristics were plotted, permitting to determine crusher's optimum operating mode. This operating mode is provided with working organs' exact antiphase oscillations at same oscillation frequency. Besides, it is shown, that at a certain disturbing frequency, carrying body becomes stationary (antiresonance), and only working organs vibrate. The latter together with elastic system n form so- Termed dynamic absorber of carrying body. Owing to vibration absorbing effect, dynamical loads on vibration exciters' bearings in the machine in question may be significantly decreased, also including impact loads. Moreover, application of this effect will permit to almost completely isolate foundation from unbalanced dynamic forces. A method of approximate estimate is proposed with respect to equivalent viscous resistance coefficient permitting to take into consideration effect of crushed material upon crusher's dynamics. The considered dynamic design of vibratory cone crusher seems to be promising for application in vibratory machines, designed for disintegration of various hard materials.

Arsentyev V.A.,REC Mekhanobr Tekhnika | Vaysberg L.A.,REC Mekhanobr Tekhnika | Ustinov I.D.,REC Mekhanobr Tekhnika
Obogashchenie Rud | Year: 2014

Scientific pre-requirements for development of promising dry and low-water-consumption technologies for finely ground mineral materials processing have been considered. Such technologies and equipment for their realization may be based on application of vibratory effects, in particular, on the effect of separated material vibrational fluidization. In vibrational fluidization state, particles move relative to one another with partial loss of contact. With that, particles detach from one another with thorough mixing. Dry separation of powder-particles smaller than 0.5 mm by their mechanical-and-physical properties is possible in the following processing operations: size classification; separation of particles according to magnetic properties; separation of particles according to electrical properties. In addition to that, subjecting of flotation slurry to vibrational effects opens the way to development of vibratory flotation machines, operating with slurries of significantly higher density, than slurries in conventional mechanical-air and pneumatic flotation machines. This in its turn creates prerequisites for drastic cuts in process water consumption in flotation - the most mass-scale process used for non-ferrous metal ores benefication. © 2014 John Wiley & Sons, Ltd.

Vaysberg L.A.,REC Mekhanobr Tekhnika | Ivanov K.S.,REC Mekhanobr Tekhnika
Obogashchenie Rud | Year: 2014

In screening process modeling, applying universal approaches as the discrete elements method, consideration of particle shape factor, accomplished, as a rule, by means of «glued» spheres approximation, is associated with an increase by the factor of many times in computing requirements, which, even without that, are significantly high. The problem of consideration of particle shape is also not sufficiently dealt with in conventional modeling methods. The article presents an analysis of bulk material particle shape factor effect upon its sieve classification. For that purpose, the full-scale experiments' results are compared with numerical simulations data, obtained through author's software effective computing medium. With that, particle shape is considered both in conventional spherical approximation, and in ellipsoidal approximation. Approximation parameters with respect to specific experimental material samples are established by means of image analysis methods. As a result, it is shown, that particle shape factor effect upon sieve classification process may be significant. Computational accuracy, with regard to ellipsoidal approximation, perceptibly exceeds that of regarding conventional spherical approximation. An improved formula is proposed for a single particle of ellipsoidal shape passing through sieve rectangular mesh, and may be used in calculations that employ any computational model.

Mikhaylova N.V.,REC Mekhanobr Tekhnika | Bizyaev O.Yu.,REC Mekhanobr Tekhnika | Spiridonov P.A.,REC Mekhanobr Tekhnika
Obogashchenie Rud | Year: 2016

Present-day trends in application of roller type devices for separation of various types of mineral and man-made raw materials were analyzed. Effects of roller type screens and separators design features and operating modes upon separation efficiency were studied. It was established, that roller type devices proved to be most successful in separation of raw materials, difficult in separation due to high moisture content, adhesion, contamination with clay or other sticky components. A new promising trend in application of roller type screens was revealed - separation of difficult man-made raw materials of complex composition: Wood wastes, construction waste, shredded automotive scrap, compost, municipal wastes. Just exactly in this niche design and operating features of roller type machines are utilized most successfully. It is proposed to use the principle under discussion in development of device for efficient recovery of glass and fine ash fractions from mixed municipal solid waste. This device simultaneously realizes two functions: glass disintegration and efficient separation of glass and small-size non-burning fractions. Its application will permit to improve the process owing to the following effects: - Additional crushing operation, performed for the purpose of glass disintegration prior to its separation, is eliminated from processing chain; - simultaneous efficient recovery of fine fractions, batteries and glass into undersize product.

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