JMS, Vol. 45, No. 4, 2009

ROCK MECHANICS

ANTI-PLANE STRAIN UNDER POST-CRITICAL DEFORMATION IN THE PROBLEM ON EQUILIBRIUM SEMI-INFINITE CRACK. PART I
A. I. Chanyshev

The paper analyzes formulations of mathematical problems on anti-plane strains in materials under post-critical deformation. Depending on a decline modulus, the system of equilibrium equations and strain compatibility conditions has one or two characteristics. Given the two characteristics, finding stress-strain state of a medium needs Cauchy stress vector and displacement vector to be set at one and the same boundary. The author shows that the post-critical deformation, if included in the problem on an equilibrium semi-infinite crack, results in the infinite growth of stresses at the crack tip under unalterable deformation. Based on this, it is necessary to account for the by now disintegrated and fractured material area that is more rigid and higher modulus under the further deformation as compared with the initial state material.

Anti-plane strain, post-critical deformation, problem formulation, crack, stress and strain distribution in the vicinity of crack tip

REFERENCES
1. F. A. McClintock and A. S. Argon, Mechanical Behavior of Materials, Reading, Mass., Addison Wesley (1966).
2. Yu. N. Rabotnov, Deformable Solid Mechanics [in Russian], Nauka, Moscow (1972).
3. G. P. Cherepanov, Brittle Fracture Mechanics [in Russian], Nauka, Moscow (1974).
4. J. A. Hult and F. A. McClintock, «Elastic-plastic stress and strain distribution around sharp notches under repeated shear,» in: Proceedings of the 9th International Congress of Applied Mechanics, 8, Brussels (1956).
5. E. I. Shemyakin, «Stress-strain state at a cut tip in elastic-plastic bodies under anti-plane deformation,» Prikl. Mekh. Tekh. Fiz., No. 2 (1974).
6. J. Rice, «Mathematical methods in failure mechanics,» in: Failure [Russian translation], 2, Mir, Moscow (1975).
7. V. V. Novozhilov, «Types of connection of stresses and strains in primary isotropic inelastic bodies (geometrical aspect),» Prikl. Mat. Mekh., 27 (1963).
8. A. A. Ilyushin, Plasticity. Basics of the General Mathematical Theory [in Russian], AN SSSR, Moscow (1963).
9. N. I. Muskhelishvili, Some Basic Problems of the Mathematical Theory of Elasticity [in Russian], AN SSSR, Moscow (1949).

DETERMINATION OF BOUNDARY CONDITIONS IN ROCKS UNDER COMPRESSION
А. A. Krasnovskii and V. E. Mirenkov

Under consideration is a process for estimation of stress-strain state at the contact of a piecewise-homogeneous rock block and stiff plates as well as at the contact of a pillar and host rocks under compression. The numerical modeling data are discussed.

Stresses, displacements, equations, pillar, rock block, stratification, contact, mathematical modeling

REFERENCES
1. G. I. Barenblatt and S. A. Khristianovich, «On roof failure in mine workings,» Izv. AN SSSR, OTN, No. 11 (1955).
2. S. G. Mikhlin, «On rock stresses above coal seam,» Izv. AN SSSR, OTN, No. 7 (1942).
3. N. I. Muskhelishvili, Some Fundamental Problems of the Mathematical Elasticity Theory [in Russian], Nauka, Moscow (1966).
4. V. M. Seryakov, «Implementation of the calculation method for stress state in rock mass with backfill,» Journal of Mining Science, No. 5 (2008).
5. V. E. Mirenkov, «Contact problems in rock mechanics,» Journal of Mining Science, No. 4 (2007).
6. M. Bonnet, «Constantinescu Inverse problems in elasticity,» Inverse Probl., No. 21 (2005).
7. A. O. Vatulyan, Inverse Problems in Mechanics of a Deformable Solid [in Russian], Fizmat-lit, Moscow (2007).
8. A. A. Krasnovskii and V. E. Mirenkov, «Analysis of deformation of the compound rock blocks with cracks,» Journal of Mining Science, No. 2 (2007).
9. V. E. Mirenkov, «On probable failure of undercut rock mass,» Journal of Mining Science, No. 2 (2009).
9. M. V. Kurlenya and V. N. Oparin, «Problems of non-linear geomechanics,» Journal of Mining Science, No. 3 (1999).
10. V. N. Oparin, A. P. Tapsiev, M. A. Rozenbaum, et al., Zonal Disintegration of Rocks and Stability of Underground Mine Workings [in Russian], Izd. SO RAN, Novosibirsk (2008).

MODELING AND FINITE ELEMENT ANALYSIS OF THE NONSTATIONARY ACTION ON. A. MULTI-LAYER POROELASTIC SEAM WITH NONLINEAR GEOMECHANICAL PROPERTIES
A. A. Nasedkina, A. V. Nasedkin, and G. Iovane

The paper discusses modeling of a multi-layer coal seam under hydrodynamic action based on the coupled equations of poroelasticity and filtration with the nonlinear relationship of permeability and porous pressure. The calculations by the finite element method use correspondence between the poroelasticity and thermoelasticity equations. The influence of input data on the size of a degassing hole area is analyzed for the couple problem and pure filtration problem.

Coal seam, methane removal, poroelasticity, fluid leakage, finite element method

REFERENCES
1. S. V. Slastunov, G. G. Kankashadze, and K. S. Kolikov, «Analytical model for hydraulic disjointing of coal seam,» Journal of Mining Science, No. 6 (2001).
2. A. A. Nasedkina and V. N. Trufanov, «Numerical modeling of hydrofracturing in a multilayer coal seam,» Journal of Mining Science, No. 1 (2006).
3. A. A. Nasedkina and V. N. Trufanov, «3D finite element model of hydrodynamic exposure of a multilayer coal seam with a fluidization zone,» Ekol. Vest. Nauch. Tsentr. Chernomor. Ekonom. Sotr., No. 3 (2006).
4. A. V. Nasedkin, A. A. Nasedkina, and V. N. Trufanov, «Some models for hydrodynamic influence on a multi-layer coal seam» in: Proceedings of the 1st International Congress of Serbian Society of Mechanics, D. Sumarac, D. Kuzmanovic (Eds.), Kopaonik, Belgrade, Serbia (2007).
5. A. V. Nasedkin and A. A. Nasedkina, «Modeling some geomechanical problems for poroelastic media in ANSYS 10.0,» in: Proceedings of the 7th Conference of CAD-FEM GmbH Users [in Russian], Poligon-press, Moscow (2007).
6. A. A. Nasedkina, A. V. Nasedkin, and G. Iovane, «A model for hydrodynamic influence on a multi-layer deformable coal seam,» Computational Mechanics, 41, No. 3 (2008).
7. Yu. A. Norvatov and A. G. Olovyanny, «Modeling of hydraulic and geomechanical processes around mine workings,» Journal of Mining Science, No. 4 (2002).
8. A. G. Olovyanny, «Mathematical modeling of hydraulic fracturing in coal seams,» Journal of Mining Science, No. 1 (2005).
9. O. Coussy, Poromechanics, J. Wiley and Sons (2004).
10. A. Norris, «On the correspondence between poroelasticity and thermoelasticity,» J. Appl. Phys. 71, No. 3 (2002).
11. H. F. Wang, Theory of Linear Poroelasticity with Applications to Geomechanics and Hydrogeology, Princ. Univ. Press (2000).
12. R. W. Zimmerman, «Coupling in poroelasticity and thermoelasticity,» Int. J. Rock Mech. & Min, Sci., 37, Nos. 1 — 2 (2000).

NUMERICAL MODELING OF LOCALIZED SHEAR DEFORMATION IN. A. CONVERGENT CHANNEL
O. P. Bushmanova and S. B. Bushmanov

The paper discusses mathematical modeling of localized shearing in a convergent channel, where displacement discontinuities occur along slip lines, and it is assumed that material behaves plastically at them and elastically outside them. Based on the finite element method, algorithms and numerical solutions for boundary value problems involving arbitrary number of slip lines are developed, as well as fields of stresses and displacements are built.

Localized shearing, slip lines, convergent channels

REFERENCES
1. V. V. Sokolvsky, Theory of Plasticity [in Russian], Vyssh. Shk., Moscow (1969).
2. L. V. Gyachev, Movement of Granular Materials in Pipes and Bunkers [in Russian], Mashinostroenie, Moscow (1968).
3. Z. Mruz and A. Dresher, «Critical equilibrium theories applied to problems on granular medium flow,» Konstr. Tekhnol. Mash., No. 2 (1969).
4. A. F. Revuzhenko, S. B. Stazhevskii, and E. I. Shemyakin, «Asymmetry of a plastic flow in the convergent symmetrical channel,» Journal of Mining Science, No. 3 (1977).
5. A. F. Revuzhenko, S. B. Stazhevskii, and E. I. Shemyakin, «Asymmetry of a plastic flow in the convergent axially symmetrical channels,» Dokl. AN SSSR, 246, No. 3 (1979).
6. A. F. Revuzhenko, Mechanics of Granular Media, Springer-Verlag Berlin Heidelberg (2006).
7. S. V. Lavrikov and A. F. Revuzhenko, «Calculating localized flows of granular media in radial channels,» Journal of Mining Science, No. 1 (1990).
8. S. V. Lavrikov and A. F. Revuzhenko, «Stochastic models in problems of the local deformation of flowing media in radial channels,» Journal of Mining Science, No. 1 (2000).
9. O. P. Bushmanova, «Numerical modeling of localized shearing,» Vych. Tekhnol., 6, Special Issue, Part II (2001).
10. O. P. Bushmanova and A. F. Revuzhenko, «Stress state of the rock mass around a working under localization of shear strain,» Journal of Mining Science, No. 2 (2002).
11. O. P. Bushmanova, «Modeling localized shearing,» Prikl. Mekh. Tekh. Fiz., No. 6 (2003).

CONSTITUTIVE RELATIONSHIPS FOR POROUS ELASTIC-PLASTIC MEDIA
Qi Chengzhi, Qian Qihu, and Wang Mingyang

Studies of mechanical behavior of porous elastic-plastic media under shock loading were undertaken within the framework of irreversible thermal dynamics and Debye forms of Helmholtz free energy. The influence of porosity on dilatancy of porous elastic-plastic media is evaluated by the effective deformation method. The state equations derived in the studies match properly irreversible thermodynamics.

Irreversible thermodynamics, Debye form, porosity, volume compression, calculation, experiment

REFERENCES
1. E. E. Lovetsky, «Mechanical effect and dissipative processes in explosion in a porous medium,» Prikl. Mekh. Tekh. Fiz., No. 2 (1981).
2. A. Goodman and S. C. Cowin, «A continuum theory for granular materials,» Arch. Rational Mech. Anal., 44 (1972).
3. D. S. Drumheller, «A theory for dynamic compaction of wet porous solid,» Int. J. Solid and Structures, 23, No. 2 (1987).
4. M. B. Rubin, D. Elatta, and A. V. Attia, «Modeling additional compressibility of porosity and the thermomechanical response of wet porous rock with application to Mt. Helen tuff,» Int. J. Solid and Structures, 33 (1996).
5. M. B. Rubin, O. Yu. Vorobiev, and L. A. Glenn, «Mechanical and numerical modeling of porous elasto-viscoplastic material with tensile failure,» Int. J. Solid and Structures, 37 (2000).
6. V. N. Kukujanov and K. Santaoiya, «Thermodynamics of viscous-plastic media with internal parameters,» Mekh. Tverd. Tela, No. 2 (1997).
7. L. D. Landau and E. М. Lifshits, Statistical Physics. Part I [in Russian], Nauka, Moscow (1995). 8. D. J. Steinberg, S. G. Cochran, and M. W. Guinan, «A constitutive model for metals applicable at high strain rates,» J. Applied Physics, 5, No. 3 (1980).
9. Gao Chzhangpen, «Applied equations of material states» [in Chinese], Advance in Mechanics, 21, No. 2 (1991).
10. Tsing Futszang, Introduction in Experimental Equations of States [in Chinese], Science, Beijing (1999).

DISPERSION EFFECT OF VELOCITIES ON THE EVALUATION OF MATERIAL ELASTICITY
Yu. I. Kolesnikov

The author employs the Kjartansson absorption model to prove that intrinsic dispersion of seismic wave velocities in absorbing media is a basic factor responsible for the differences between elastic rock parameters measured dynamically and statically. Dispersion of Young’s modulus predicted by this model for a frequency range from millihertz to tens of kilohertz matches well the experimental data obtained for polyvinyl chloride plastic used as a test material in the study case.

Static and dynamic elasticity moduli, Kjartansson absorption model, intrinsic dispersion of velocities

REFERENCES
1. V. N. Nikitin, Relationship between Dynamic Ed and Static Es Moduli for Hard Rocks. Exploration and Development Geophysics [in Russian], Issue 45, Gostoptekhizdat, Moscow (1962).
2. G. Simmons and W. F. Brace, «Comparison of static and dynamic measurements of compressibility of rocks,» J. Geophys. Res., 70, No. 22 (1965).
3. A. I. Savich and Z. G. Yashchenko, Investigation of Elasticity and Deformability of Rocks by Seismic and Acoustic Methods [in Russian], Nedra, Moscow (1979).
4. C. H. Cheng and D. H. Johnston, «Dynamic and static moduli,» Geophys. Res. Lett., 8, No. 1 (1981).
5. A. N. Tutuncu, A. L. Podio, A. R. Gregory, and M. M. Sharma, «Nonlinear viscoelastic behavior of sedimentary rocks, Part I: Effect of frequency and strain amplitude,» Geophysics, 63, No. 1 (1998).
6. E. M. Averko, Yu. I. Kolesnikov, and A. I. Sherubnev, «Some differences in properties of continuum in statics and seismology (model investigations),» in: Multiwave Seismic Investigations within Geoacoustic Frequency Range, Collected Works [in Russian], IGiG, Novosibirsk (1987).
7. Seismic Exploration: Geophysicist Handbook [in Russian], Nedra, Moscow (1981).
8 Yu. I. Vasil’ev, Two summaries of constants for attenuation of elastic oscillations," Izv. AN SSSR, Geofiz., No. 5 (1962).
9. L. Knopoff, «Q,» Rev. Geophysics, 2, No. 4 (1964).
10. P. B. Attewell and Y. V. Ramana, «Wave attenuation and internal friction as functions of frequency in rocks,» Geophysics, 31, No. 6 (1966).
11. P. C. Wuenschel, «Dispersive body waves — an experimental study,» Geophysics, 30, No. 4 (1965).
12. L. V. Molotova, «On dispersion of bulk-wave velocities in rocks,» Izv. AN SSSR, Geofiz., No. 8 (1966).
13. D. C. Ganley and E. R. Kanasewich, «Measurement of absorption and dispersion from check shot surveys,» J. Geophys. Res., 85, No. B10 (1980).
14. B. J. Brennan and F. D. Stacey, «Frequency dependence of elasticity of rock — test of seismic velocity dispersion,» Nature, 268, No. 5617 (1977).
15. W. F. Murphy, «Seismic to ultrasonic velocity drift: intrinsic absorption and dispersion in crystalline rocks,» Geophys. Res. Lett., 11, No. 12 (1984).
16. S. Ya. Kogan, «Brief review on theories of seismic wave absorption,» Izv. AN SSSR: Fiz. Zemli, No. 11 (1966).
17. E. Kjartansson. «Constant Q — wave propagation and attenuation,» J. Geophys. Res., 84, No. B9 (1979).
18. E. M. Averko and Yu. I. Kolesnikov, «A model of seismic wave absorption,» in: Geoacoustic Studies in Multiwave Seismic Exploration. Collected Works [in Russian], IGiG, Novosibirsk (1987).
19. K. Winkler and A. Nur, «Seismic attenuation: Effects of pore fluids and frictional sliding,» Geophysics, 47, No. 1 (1982).
20. D. H. Johnston and M. N. Toksoz, «Ultrasonic P- and S-wave attenuation in dry and saturated rocks under pressure,» J. Geophys. Res., 85, No. B2 (1980).

ROCK FAILURE

CHANGES IN STRUCTURE OF NATURAL HETEROGENOUS MATERIALS UNDER DEFORMATION
V. S. Kuksenko, Kh. F. Makhmudov, V. A. Mansurov, U. Sultonov, and M. Z. Rustamova

Compression testing of granite samples has been carried out to study their structure and its influence on microcracking by comparing the measured grains and microcracks on the thin sections of granite before and after the testing. The authors suggest that the results may be transferred onto lager scale levels with the purpose of forecasting a macroscopic fracture.

Heterogeneity, strain, granite sample, quartz grains

REFERENCES
1. E. M. Smekhov, Theoretical and Methodical Basics for Localizing Natural Fractured Collectors of Oil and Gas [in Russian], Nedra, Leningrad (1974).
2. I. A. Turchaninov, M. A. Iofis, and E. V. Kaspar’yan, Foundations of Rock Mechanics [in Russian], Nedra, Leningrad (1977).
3. K. T. Tadzhibaev, Deformation and Failure of Rocks [in Russian], Ilim, Frunze (1986).
4. D. A. Lokner, J. D. Byerlee, V. Kuksenko, A. Ponomarev, and A. Sidorin, «Quasi-static fault growth and shear fracture energy in granite,» Nature, 350 (1991).
5. V. S. Kuksenko, «Diagnostics and prediction of failure of large objects,» Fiz. Tverd. Tela, 47, No. 5 (2005).
6. G. A. Sobolev and A. V. Ponomarev, Earthquake Physics and Precursors [in Russian], Nauka, Moscow (2003).
7. A. N. Stavrogin and A. G. Protosenya, Mechanics of Rock Deformation and Failure [in Russian], Nedra, Moscow (1992).
8. M. A. Sadovsky, «Natural lumpiness of rocks,» Dokl. AN SSSR, 274, No. 4 (1979).

NUMERICAL ANALYSIS OF THE KICKBACK ENERGY UNDER GLANCING COLLISION OF. A. FLAT END STRIKER ASSEMBLY AND. A. RIGID BARRIER
Yu. P. Meshcheryakov

Based on the numerical analysis of the kickback dynamics under glancing collision of an elastic striker assembly and a rigid barrier, the components of the total kinetic energy of the striker assembly after kickback are calculated depending on the collision angle, and the results are discussed.

Elastic kickback, striker assembly, glancing collision, rigid barrier, energy

REFERENCES
1. N. I. Nikishin, «Rebound of a striking part of jackhammers and concrete breakers and its effect on the tool performance,» in: Transactions of VNIIStroidormash Vol. XXX. Analysis and Calculation of Impact Devices [in Russian], VNIIStroidormash, Moscow (1961).
2. N. G. Zakablukovskii, G. N. Pokrovskii, and B. N. Serpeninov, «Effect of loading rate, as well as ratios of weights and rigidities of a tool and its striking part on the impact efficiency,» in: Impact Transmission and Impact Machines [in Russian], IGD SO AN SSSR, Novosibirsk (1976).
3. O. D. Alimov, V. K. Manzhosov, and V. E. Erem’yants, «Estimating effect of parameters of an impacting system and treated medium on the post-impact velocity of striker assembly,» Journal of Mining Science, No. 2 (1984).
4. O. D. Alimov, V. K. Manzhosov, and V. E. Erem’yants, Impact. Deformation Wave Propagation in Impacting Systems [in Russian], Nauka, Moscow (1985).
5. V. E. Erem’yants and B. S. Sultanaliev, «Results of investigation into the coefficient of hammer head recoil,» Journal of Mining Science, No. 2 (2004).
6. V. E. Erem’yants, E. S. Dandybaev, and T. D. Umerbekov, «Head recoil on impact on a waveguide interacting with a steel pipe,» Journal of Mining Science, No. 2 (2005).
7. S. P. Timoshenko, Course on Theory of Elasticity [in Russia], Naukova Dumka, Kiev (1972).
8. Yu. P. Meshcheryakov, «Numerical modeling of severance of radiation-exposed fuel assemblies,» Prikl. Mekh. Tekh. Fiz., 47, No. 3 (2006).
9. Y. P. Meshcheryakov and N. M. Bulgakova, «Thermoelastic modeling of microbump and nanojet formation on nanosize gold films under femtosecond laser irradiation,» Appl. Phys. A., 82 (2006).

SCIENCE OF MINING MACHINES

IMPROVEMENT PROSPECTS FOR AIR HAMMERS IN BUILDING AND CONSTRUCTION WORKS
B. N. Smolyanitskii, I. V. Tishchenko, and V. V. Chervov

Reasoning from an analysis of the potentiality for air hammers to achieve higher energy indices in impact driving of steel elements in soil, the authors show that utilization of boost air pressure sources in impact machines with an elastic valve in air distribution system holds much promise in this case. The paper also presents test data for an experimental air hammer with adjustable parameters.

Vibration, air hammer, elastic valve, air pressure, flow rate, blow frequency, blow energy

REFERENCES
1. H. Nestle (Ed.), Constructor’s Guide. Construction Machinery, Designs and Technologies [Russian translation], Tekhnosfera, Moscow (2007).
2. N. A. Tsytovich, Soils Mechanics [in Russian], Vyssh. Shk., Moscow (1979).
3. V. A. Bauman and I. I. Bykhovskii, Vibration Machines and Processes in Construction [in Russian], Vyssh. Shk., Moscow (1977).
4. State Standard R 51041–97. Pile-Driving Hammers. General Specifications [in Russian], Izd. Standartov, Moscow (1998).
5. Yu. V. Dmitrievich, Modern Domestic and Foreign Pile-Driving Diesel Hammers [in Russian], Mashinostroenie, Moscow (1990).
6. A. G. Odyshev, B. A. Zorin, S. A. Shushenachev, et al., «Pile-driving hydraulic hammers,» Stroit. Dor. Mash., No. 8 (1990).
7. K. E. Bessonov, «Pile-driving hydrohammers,» Stroit. Dor. Mash., No. 2 (2005).
8. A. D. Kostylev, V. P. Gileta, et al., Pneumatic Punches in Construction [in Russian], Nauka, Novosibirsk (1987).
9. B. N. Smolyanitskii, V. V. Chervov, V. V. Trubitsyn, et al., «New pneumatic percussion machines for special construction services,» Mekhaniz. Stroit., No. 7 (1997).
10. B. N. Smolyanitskii, I. V. Tishchenko, V. V. Chervov, et al., «Sources for productivity gain in vibro-impact driving of steel elements in soil in special construction technologies,» Journal of Mining Science, No. 5 (2008).
11. G. Kyun, L. Shoible, and Kh. Shlik, Underground Driving of Inaccessible Pipelines [in Russian], Stroiizdat, Moscow (1933).
12. V. V. Chervov, «Impact energy of pneumatic hammer with elastic valve in back-stroke chamber,» Journal of Mining Science, No. 1 (2004).
13. V. V. Chervov and A. S. Smolentsev, «Test stand for pneumatic hammers,» Journal of Mining Science, No. 6 (2007).
14. K. S. Gurkov, V. V. Klimashko, A. D. Kostylev, et al., Pneumatic Drift Punches [in Russian], Novosibirsk (1990).
15. V. V. Chervov, I. V. Tishchenko, and A. V. Chervov, «Influence of the air distribution elements in the pneumatic hammer with an elastic valve on the energy carrier rate,» Journal of Mining Science, No. 1 (2009).

PRINCIPAL DIMENSIONS OF THE SHORT-STROKE ELECTROMAGNET MOTOR FOR. A. SEISMIC WAVE GENERATOR
V. P. Pevchev

The paper describes calculation of principal dimensions for the short-stroke pulsed electromagnetic motor of a seismic wave generator, including the magnet core length to side pole width ratio, as well as presents a design procedure.

Pulsed seismic vibrator, short-stroke electromagnet, force intensity

REFERENCES
1. V. P. Smirnov, «Electromagnetic seismic oscillators, series Enisey-SEM/-KEM,» Prib. Sist. Razved. Geofiz., No. 1 (2003).
2. G. I. Molokanov, «Impact-induced transformation of the mechanical energy into the seismic energy,» Razved. Geofiz., Issue 65 (1979).
3. V. K. Bul’, Basics for the Theory and Calculation of Magnetic Circuits [in Russian], Energia, Moscow (1967).
4. A. V. L’vitsyn, G. G. Ugarov, V. N. Fedonin, et al., «Power drive cylindrical electromagnets with high specific indices,» in: Electromagnetic Impacting Machines [in Russian], Novosibirsk (1978).
5. F. V. Dolinskii and M. N. Mikhailov, Theory of Strength of Materials. Short Course [in Russian], Vyssh. Shk., Moscow (1986).
6. V. V. Ivashin and V. P. Pevchev, «Russian Federation Paten No. 2172497, MKI 7G01V 1/04. Power electromagnet for pulsed nonexplosive source,» Byull. Izobret., No. 23 (2001).
7. V. V. Ivashin, L. I. Karkovskii, and S. V. Ponosov, «Analytic definition of the optimal dimension of a magnet core for the electromagnet in seismic vibrators,» in: Proceedings of the Russian Conference in Partnership with Foreign Scientists «Technical Progress in Machine Engineering» [in Russian], TolGU, Tolyatti (2002).

MINERAL MINING TECHNOLOGY

INFLUENCE OF GEOLOGICAL AND TECHNOLOGICAL FACTORS ON THE INTERNAL DUMP CAPACITY IN FLAT DEPOSITS
A. A. Zaitseva and G. D. Zaitsev

The authors describe a research into internal dumping in flat deposits under downdip mining and show that the internal dump capacity changes subject to the dump parameters and physico-mechanical properties of overburden in conformity with the found regulations.

Mathematical modeling, open pit, seam, internal dump, layer

REFERENCES
1. E. I. Vasil’ev, A. A. Zaitseva, and V. I. Cheskidov, «Mining regime stabilization in working inclined deposits by blocks,» Journal of Mining Science, No. 6 (1999).
2. E. I. Vasil’ev and A. A. Zaitseva, «Computer technology for selection of internal dump and open pit parameters,» Journal of Mining Science, No. 5 (2001).
3. A. S. Tanaino, Open Pit Planning Automation. Mining Geometry Calculations [in Russian], Nauka, Novosibirsk (1986).
4. G. G. Poklad, P. S. Shpakov, and V. N. Dolgonosov, «Scientific recommendations on internal dumping parameters for Shubarkolsky Open Pit,» Gorn-Analit. Byull., No. 6 (2000).

MINE AERO-GAS DYNAMICS AND THERMOPHYSICS

APPLICATION OF CARBON DIOXIDE (CO₂) FOR CONTROLLING SUBSURFACE FIRE AREA: INDIAN CONTEXT
N. K. Mohalik, V. K. Singh, and R. V. K. Singh

In bord and pillar method of mining, the panels are sealed off after depillaring. Depending upon the site specific condition, 40 to 45 % coal are left in depillared panel as stook, loose coal left in goaf, hard coal on floor and roof of the panel. The left out coals in goaf area start oxidation, and this leads to spontaneous heating in side sealed off area. For assessment of fire in underground coal mines, thermo-compositional monitoring plays an important role. This paper presents scientific relevance and selective criteria for use of inert gas for control of subsurface fire. Finally the paper discusses spontaneous heating problem in sealed off area and application of inertisation technology by using CO₂ to prevent and control sealed off fire at Haripur Colliery, Kenda Area, ECL, India.

Spontaneous combustion, inertisation, carbon dioxide, sealed off area

REFERENCES
1. A. K. Sinha and A. K. Rudra, «Spontaneous heating and fire in Jharia and Raniganj Coalfields — challenges and remedies,» in: Proceedings of National Seminar on VSE-2001 (2001).
2. A. Adamus, «Review of nitrogen as an inert gas in underground mines,» Journal of Mine Ventilation Society of South Africa, 54, No. 3 (2001).
3. N. K. Mohalik, V. K. Singh, J. Pandey, and R. V. K. Singh, «Proper sampling of mine gases, analysis and interpretation — a pre requisite for assessment of sealed off fire area,» Journal of Mines Metals & Fuels, 54, Nos. 10 and 11 (2006).
4. D. D. Tripathi and V. K. Singh, «Abatement of underground mine fire — technology options,» in: Proceedings of the National Symposium on Sustainable Mining Technology: Present and Future, Anna University, Chennai (2002).
5. Mine Rescue Services Manual, Singareni Collieries Company Ltd. (2005).
6. CIMFR S&T, «Study for early detection of the occurrences of spontaneous heating in blasting gallery method and to evaluate suitable measures to prevent and control spontaneous heating in thick coal seams,» Report (2002).
7. CIMFR Project Report, «Scientific investigation and advice for dealing with fire in goaved out panel D & F lying between No- 1 & No-2 Incline of Haripur Colliery, Kenda Area, ECL, Project No. GC/MS/102/2002–03.»
8. R. V. K. Singh, G Sural, N. K. Mohalik, and V. K. Singh, «Application of carbon dioxide for control of sealed off fire area — a case study», CMTM (2006).

MINERAL DRESSING

ROLE OF DIXANTOGEN IN FROTH FLOTATION
V. E. Vigdergauz and S. A. Kondrat’ev

Mechanism of dixantogen action in froth flotation is discussed. It is shown that this reagent eliminates kinetic constraints during formation of a flotation complex, rather than improves hydrophobicity of a mineral surface.

Flotation agent, physical and chemical sorption forms, xanthate, dixantogen, surface pressure, electrochemical polarization, induction time

REFERENCES
1. V. I. Klassen and I. N. Plaksin, «On mechanism of apolar reagent action in coal flotation,» Dokl. Akad. Nauk SSSR, 95, No. 4 (1954).
2. A. A. Abramov, S. B. Leonov, and M. M. Sorokin, Chemistry of Flotation Systems [in Russian], Nedra, Moscow (1982).
3. S. A. Kondrat’ev, «Physically sorbed collectors in froth flotation and their activity, Parts I and II,» Journal of Mining Science, respectively, No. 6 (2008) and No. 2 (2009).
4. D. G. Suciu, О. Smigelschi, and Е. Ruckenstein, «The spreading of liquids on liquids,» Journal of Colloid and Interface Science, 33, No. 4 (1970).
5. I. A. Kakovsky and V. M. Arashkevich, «Studies of properties of organic disulfides,» in: Proceedings of the 8th International Congress on Mineral Processing [in Russian], Leningrad (1969).
6. V. E. Vigdergauz and A. I. Dorofeev, «Electrochemical study of xanthate redox-transitions on a platinum electrode and their effect on flotation,» Vest. RUDN, Engineering Researches Series, 12, No. 1 (2006).
7. B. E. Goryachev, «Surface tension of «dixantogen — air — dixantogen — water» interface,» Tsvet. Metally, No. 11 (2006).
8. V. A. Chanturia, Perspectives of Monitoring the Degree of Oxidation of Xanthate to Dixantogen in Flotation Process. Control of Ion Composition of Ore Pulp in Flotation [in Russian], Nauka, Moscow (1974).

CHEMICAL DEMINERALIZATION OF DIFFERENT METAMORPHIC GRADE COALS
T. S. Yusupov, L. G. Shumskaya, and A. P. Burdukov

The paper analyzes a process of deep mineralization of various metamorphic grade coals pre-ground in different destructive units, namely, in centrifugal-planetary mill and disintegrator. Coal dispergation in higher energy intensive mills greatly enhances inorganic component extraction to acidic solutions. This is explained by distortion of crystal structure and amorphization of minerals under various kinds and different intensity mechanical actions.

Jet coal, lean coal, intensive mechanical action, chemical demineralization

REFERENCES
1. V. A. Ruban, «Coal concentration state-of-the-art,» Khim. Tverd. Topl., No. 1 (2005).
2. M. Steel Karen and John W. Patrick, «The production of ultra clean coal by chemical demineralization,» in: Fuel (2001).
3. R. T. Yang., S. K. Das, and B. M. Tsai, «Coal demineralization using sodium hydroxide and acid solutions,» in: Fuel (1985).
4. S. V. Gagarin, «Means of improvement of coal quality,» Koks Khimia, No. 5 (1999).
5. P. Balaz, R. B. LaCount, and D. G. Kern, «Chemical treatment of coal by grinding and aqueous caustic leaching,» in: Fuel (2001).
6. I. S. Blagov, Low-Ash and Superclean Coal Concentrates [in Russian], Nauka, Moscow (1968).
7. T. S. Yusupov, L. G. Shumskaya, and A. P. Burdukov, «Effect of mechanical dispersion of lignite on its thermal decomposition,» Journal of Mining Science, No. 5 (2007).
8. T. S. Yusupov and L. G. Shumskaya, «Thermal analysis of the thermal-acidic destruction of mechanically activated brown coal,» Khim. Tverd. Topl., No. 5 (2008).
9. E. S. Lapteva, T. S. Yusupov, and A. S. Berger, Physico-Chemical Alteration of Laminated Silicates under Mechanical Activation [in Russian], Nauka, Novosibirsk (1981).

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