Improved Multi-Scale Computational Modelling of Fugitive Dust Dispersion from Surface Mining Operations

Authors: Lowndes I.S., Silvester S.A., Kingman S.W., Hargreaves D.M.

Year: 2009

Issue: 04

Pages: 178-186

Abstract

The extraction and processing of minerals from surface mines and quarries can produce significant fugitive emissions as a result of site activities such as blasting, unpaved road haulage, loading, primary crushing and stockpiling. Uncontrolled fugitive dust emissions can present serious environmental, health, safety and operational issues impacting both site personnel and the wider community. Simulation technology is finding increasing use for the purposes of advanced warning of potential problem emissions in addition to providing a basis for future planning applications where demonstrable compliance with regulatory requirements are necessary. The initial re-entrainment and subsequent dispersion of fugitive dust presents a process complicated by the combination of the in pit topography, the surrounding natural topography and the dynamic nature of emissions from these sites. These factors impact upon the accuracy and reliability of the conventional Gaussian plume based computational prediction methods employed for regulatory compliance and IPPC applications. This paper proposes that optimal modelling of open pit emissions may be more accurately achieved by the use of a multi-scale predictive modelling approach utilising computational fluid dynamic (CFD) methods for high resolution near source dispersion and conventional Gaussian based methods for far field dispersion modelling.
This paper presents a numerical based flow and dispersion analysis of a typical UK based open pit utilising CFD in conjunction with a conventional Gaussian plume based methods. Typical operating emissions and meteorological conditions are obtained from long term data records collected at a large operating quarry extraction operation in the UK. Emissions are modelled using a Lagrangian framework within conventional atmospheric boundary layer (ABL) profiles expressed as functions of turbulence and velocity parameters under assumed neutral conditions. Results are presented in terms of the impact of site topography on in pit retention as compared to the Gaussian based method.

Tags: CFD; dust dispersion; surface mines

Bibliography

    1. Anon (1995) USEPA, AP-42, Compilation of air pollution factors, Vol 1: Stationary point and area sources, Chapters 13.2.4, Aggregate handling and storage piles, Research Triangle Park, NC, USA.
    2. Anon (1998) USEPA, AP-42, Compilation of air pollution factors. Vol 1: Stationary point and area sources. Chapter 13.2.2: Unpaved roads, Research Triangle Park, NC, USA.
    3. Anon (1999) ADMS User Guide. CERC Ltd, Cambridge, UK.
    4. Appleton, T.J., S.W. Kingman, I.S. Lowndes and S.A. Silvester (2006) The development of a modelling strategy for the simulation of fugitive dust emissions from in-pit quarrying activities: a UK case study. International Journal of Mining, Reclamation and Environment, 20, 1, pp 57–82.
    5. Atkinson, B.W. (1995) Introduction to the fluid dynamics of mesoscale flow fields, in Diffusion and Transport of Pollutants in Atmospheric Mesoscale Flow Fields. Kluwer Academic Publishers, Dordrecht, pp.1–20
    6. Baklanov, A.A. (1984) Determining the propagation of impurity in the atmosphere of a pit on the basis of mathematical models. Soviet Mining Science, 20(5), pp. 402–407.
    7. Baklanov, A.A. (1986) A method of evaluating the energy characteristics of the air in an open pit mine. Soviet Mining Science, 22(1), pp. 66–70.
    8. Baklanov, A.A. (1995) Numerical modelling of atmosphere processes in mountain cirques and open pits. Proceedings of International Conference on Air Pollution, Porto Carras, Greece, pp. 231–238.
    9. Baklanov, A.A. and O.Yu. Rigina (1994) Research of local zones atmosphere normalization by artificial currents. Proceedings of the 2 nd International Conference on Air Pollution, WIT, Computational Mechanics Publications, pp. 553–561.
    10. Belousov, V.I. (1985) Natural dynamic ventilation of open mines. Soviet Mining Science, 21(3), pp. 264–267.
    11. Belousov, V.I. (1990) Ventilation of open-pit mines by controlling the boundary layer of the wind stream. Soviet Mining Science, 25 (3), pp. 267–270.
    12. Bukhman, Y.Z, A.L. Kazakov and V.I. Belousov (1976) Manual to open pit ventilation in USSR nonferrous metallurgy (in Russian). Izd. VTsM SSSR, Moscow.
    13. Docx, J., S.W. Kingman, E.H. Lester, I.S. Lowndes, S.A. Silvester and T. Wu (2007) An investigation into unpaved road emissions from a UK surface limestone quarry using cylindrical adhesive pad collectors and image analysis. International Journal of Mining, Reclamation and Environment, 21, 1, pp. 1–18.
    14. Kim, H. G., V.C. Patel and M.L. Chuong (2000) Numerical simulation of wind flow over hilly terrain. Journal of Wind Engineering and Industrial Aerodynamics, 87, pp. 45–60.
    15. Nikitin, V.S. and N.Z. Bitkolov (1975) Mine Ventilation (in Russian). Nedra, Moscow.
    16. Peng, X. and G.R. Lu (1995) Physical modelling of natural wind and its guide in a lrge open pit, Journal of Wind Engineering and Industrial Aerodynamics, 54/55, pp. 473–481.
    17. Petavratzi, E., S.W. Kingman and I.S. Lowndes (2007) Assessment of the dustiness and the dust liberation mechanisms of limestone quarry operations, Chemical Engineering and Processing, 46, pp. 1412–1423.
    18. Petavratzi, E., S.W. Kingman and I.S. Lowndes (2005) Particles from mining operations: A review of sources, effects and regulations. Minerals Engineering, 18, pp. 1183–1199.
    19. Reed, W.R.(2005) Significant dust dispersion models for mining operations. NIOSH IC 9478, Pittsburgh, PA, USA.
    20. Riddle, A., D. Carruthers, A. Sharpe, C. McHugh and J. Stocker (2004) Comparisons between Fluent and ADMS for atmospheric dispersion modelling. Atmospheric Environment, 38, pp. 1029–1038.
    21. Silvester, S.A., I.S. Lowndes and S.W. Kingman (2006) The application of computational fluid dynamics to the improved prediction of dust emissions from surface quarrying operations. Proceedings of the Fifth International Conference on CFD in the Process Industries, CSIRO, Melbourne, Australia, pp. 1–6.
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