Skip to main content

Ore and Backfill Dilution in Underground Hard Rock Mining


The ore dilution is generally defined as the degradation of economical and valuable ore with the addition of the unwanted host rock, failed backfilled material and or ore material considered below the cut-off the grade. The importance of ore dilution on the profitability of a mining operation is very well known and also well documented, since, it adds to the cost of mining, hauling, transportation, milling and processing etc. It also differs from one mining operation to another, the ore type being extracted, the type of the host rock present and type of mining method applied, type of backfilling method and material used, including other mining parameters. The ore dilution is generally expected at all stages of mining operation including the very first step of stoping in the case of hard rock mining, where, the low-grade ore is extracted un-intentionally or intentionally to insure the safe mining environment including excavation stability and or towards the easy movement of men and machineries. It is well known that the numerous parameters including mining and rock mechanics influence the occurrence of ore dilution in the case of underground hard rock mining. Herewith, through review study, the problem of ore dilution, various factors affecting dilution, its measurement and possible control measures is discussed.

This is a preview of subscription content, access via your institution.

Fig. 1
Fig. 2
Fig. 3
Fig. 4
Fig. 5
Fig. 6
Fig. 7
Fig. 8


  1. Bawden, W.F., The Use of Rock Mechanics Principles in Canadian Underground Hard Rock Mine Design, Comprehensive Rock Eng., Vol. V, Hudson, J.A. (Chief Ed.), Pergamon Press, 1993.

  2. Tatman, C.R., Mining Dilution in Moderate and Narrow Width Deposits, Underground Min. Methods—Eng. Fundamentals and Int. Case Studies, Hustrulid, W.A. and Bullock, R.L. (Eds.), SME Publications, 2001.

  3. Cowling, R., 25 Years of Mine Filling Developments and Directions, Proc. of the 6th Int. Symp. on Mining with Backfill, Brsibane, Australia, 1998.

  4. Stacey, T.R. and Kirsten, H.A.D., Backfill Support in Deep Level Tabular Mining—Predicted Performance at Great Depth, Rock at Great Depth, Maury & Fourmaintraux (Eds.), Balkema, Rotterdam, 1989, ISBN 9061919754.

  5. Henning, J.G. and Mitri, H.S., Numerical Modeling of Ore Dilution in Blasthole Stoping, Int. J. Rock Mech. Min. Sci., 2007, vol. 44, no. 5, pp. 692–703.

    Article  Google Scholar 

  6. Henning, J.G. and Mitri, H.S., Assessment and Control of Ore Dilution in Longhole Mining: Case Studies, Geotech. Geol. Eng., 2008, vol. 26, pp. 349–366.

    Article  Google Scholar 

  7. Mouhabbis, H.Z.E., Mitri, H.S., Bedard, N., and Lecomte, E., Effect of Stope Undercutting on Its Wall Overbreak, Proc. 43rd US Rock Mechanics Symp., Asheville, NC, 2009, Paper No. ARMA 09-200.

  8. Hughes, R., Mitri, H.S., and Lecomte, E., Examining the Influence of Stope Strike Length on Unplanned Ore Dilution in Narrow Vein Longitudinal Mining, Proc. 44th US Rock Mechanics Symp. and 5th U.S.—Canada Rock Mech. Symp., Salt Lake City, UT, 2010, Paper No. ARMA 10-392.

  9. Dunne, K. and Pakalnis, R., Dilution Aspects of a Sublevel Retreat Stope at Detour Lake Mine, Rock Mechanics Tools and Techniques, Vol. I, Aubertin, M., Hassani, F., and Mitri, H.S. (Eds.), 1996, Balkema, pp. 305–313.

  10. Brechtel, C.E. and Hardy, M.P., Design of Pillars with Backfill Interaction—A Case Study, Comprehensive Rock Eng., Vol. II, Hudson, J.A. (Chief Ed.), Pergamon Press, 1993.

  11. Brechtel, C.E., Struble, G.R. and Guenther, B., Underhand Cut-and-Fill Mining at the Murray Mine, Jerritt Canyon Joint Venture, Chapter 38,: Underground Min. Methods—Eng. Fundamentals and International Case Studies, Hustrulid, W.A. and Bullock, R.L. (Eds.), 2001, SME Publications, pp. 333–337.

  12. Yu, T.R., Some Factors Relating to the Stability of Consolidated Rockfill at Kidd Creek, Innovations in Mining Backfill Technology, Hassani et al. (Eds.), 1989, Balkema, Rotterdam, pp. 279–286.

  13. Lilley, C.R. and Chitombo, G.P.F., Development of a Near Field Damage Model for Cemented Hydraulic Fill, Proc. Minefill’98, Brisbane, 1998.

  14. Bagde, M.N. and Mitri, H.S., Numerical Analysis of Backfill Failure due to Adjacent Stope Mining, Proc. Int. Conf. on Ground Improvement & Ground Control—Transport Infrastructure Development and Natural Hazards Mitigation, Univ. Wollongong, Australia, 2012.

  15. Bagde, M.N. and Mitri. H.S., Numerical Analysis of Backfill Face Stability, Proc. Conf. Earth and Planetary Science—Global Challenges, Policy Framework & Sustainable Development for Min. of Min. & Fossil Energy Resources 2015-20, KNIT Surathakal, India, 2015. DOI: 10.1016/j.proeps.2015.06.021.

    Article  Google Scholar 

  16. Bagde, M.N., Emad, M.Z., Mitri, H.S., Thibodeau, D., Isagon, I., and Gustas, B., Examining the Influence of Stope Dimensions and Mining Sequence on Backfill Dilution: A Review with Case Study, Proc. Int. Conf. on Technological Challenges and Management Issues for Sustainability of Mining Industries (TMSMI), NIT Rourkela, India, 2011.

  17. Hassani, F.P., Mortazavi, A., and Shabani, M., An Investigation of Mechanisms Involved in Backfill-Rock Mass Behavior in Narrow Vein Mining, J. Southern African Institute of Min. and Metallurgy, 2008, vol. 106, pp. 463–472.

    Google Scholar 

  18. Emad, M.Z., Dynamic Performance of Cemented Rockfill under Blast-Induced Vibrations, Ph. D. Thesis, McGill University, Montreal, Canada, 2013.

  19. Gool, B.S., Effects of Blasting on the Stability of Paste Fill Stopes at Cannington Mine, Ph. D. Thesis, James Cook University, Townsville, 2007.

  20. Maclssac, H.S. and Swan, G., Case Study: Strathcona Deep Copper Mine, Underground Min. Methods—Eng. Fundamentals and Int. Case Studies, Hustrulid, W.A. and Bullock, R.L. (Eds,), SME Publications, 2001, pp. 351–354.

  21. Roy, R.L., Evolution of Undercut-and-Fill at SMJ’s Jouac Mine, France. Chapter 42, Underground Min. Methods—Eng. Fundamentals and Int. Case Studies, Hustrulid, W.A. and Bullock, R.L. (Eds.), SME Publications, 2001, pp. 355–357.

  22. De, L.V.J., Hard Rock Miner’s Handbook, McIntosh Eng., 2000.

  23. Henning, J.G., Mitri, H.S., and Kaiser, P.K., Evaluation of Stress Influences on Ore Dilution: A Case Study, Proc. DC Rocks 2001: Rock Mech. in the National Interest, 38th U.S. Rock Mechanics Symp., 2001.

  24. Clark, L.M. and Pakalnis, R., An Empirical Design Approach for Estimating Unplanned Dilution from Open Stope Hanging Walls and Footwalls, Proc. 99th CIM Annual General Meeting, Vancouver, British Columbia, 1997.

  25. Pakalnis, R., Poulin, R., and Hadjigeorgiou, J., Quantifying the Cost Dilution in Underground Mines, Min. Eng., 1995, vol. 47, no. 12.

  26. Brady, B.H.G. and Brown, E.T., Rock Mechanics for Underground Mining, 3rd Edition, Kluwer Academic Publishers, New York-Boston-Dordrechit-London-Moscow, 2004.

Download references

Author information

Authors and Affiliations


Corresponding author

Correspondence to M. N. Bagde.

Rights and permissions

Reprints and Permissions

About this article

Verify currency and authenticity via CrossMark

Cite this article

Bagde, M.N. Ore and Backfill Dilution in Underground Hard Rock Mining. J Min Sci 57, 995–1005 (2021).

Download citation

  • Received:

  • Revised:

  • Accepted:

  • Published:

  • Issue Date:

  • DOI:


  • ore dilution
  • backfill
  • hard rock mining
  • stoping
  • measurement
  • control measures