Authors: Godbout, J; Bussière, B; Benzaazoua, M; Aubertin, M


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Godbout, J, Bussière, B, Benzaazoua, M & Aubertin, M 2010, 'Influence of pyrrhotite content on the mechanical and chemical behaviour of cemented paste backfill', in R Jewell & AB Fourie (eds), Proceedings of the Thirteenth International Seminar on Paste and Thickened Tailings, Australian Centre for Geomechanics, Perth, pp. 163-173,

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The chemical weathering related to sulphide minerals oxidation within mine backfill in underground stopes can cause serious problems, such as the loss of mechanical strength due to sulphate attack. This can also lead, under specific (extreme) conditions, to excessive self-heating of the backfill and to oxygen depleted atmosphere. Previous studies indicate that sulphide minerals contained in cemented paste backfill (CPB) are less reactive (i.e. less prone to oxidation) than those contained in hydraulic backfill (HB) because the favourable hydraulic properties of CPB can help maintain a high degree of water saturation (often more than 85%) in the fill material. This paper presents results from an investigation of the influence of pyrrhotite content on the physico-chemical behaviour of cemented paste and hydraulic backfills. Oxygen-consumption (OC) tests, uniaxial compressive strength (UCS) tests, and a post-testing characterisation were performed on different mixtures of cemented backfills made of tailings with 5% wt of binder and various percentages of pyrrhotite (2 to 15%). Tailings without binder were also assessed with the OC test (as control samples). All samples were cured under controlled temperature and moisture conditions (30°C and 100% respectively) to simulate curing under warm mine site conditions, for periods of 3, 7, 28, 56, 182, and 365 days. The OC tests results show that pyrrhotite-rich tailings without binder can be very reactive; the consumed oxygen flux measured can exceed 35 mol/m2/day when these are exposed to atmospheric concentration. OC tests also show that the addition of binder (Portland cement) in the backfill mixtures reduces their reactivity; a more significant reduction was observed for paste backfill samples compared with hydraulic backfill specimens. The OC tests results furthermore indicate a decrease of the control samples (tailings without binder) reactivity over time, suggesting that other factors, such as passivation of the pyrrhotite grains surface during weathering, could also influence the evolution of backfill reactivity. The UCS tests results show that paste backfill samples reached higher strength than hydraulic backfill. However, a progressive loss of strength was also observed for all backfill mixtures after a few months, probably due to sulphate attack.

Aubertin, M., Bussière, B. and Bernier, L. (2002) Environnement et gestion des résidus miniers, Presses Internationales
Polytechnique, Corporation de l'École Polytechnique de Montréal, Montréal, Manual on CD.
Bayah, J., Meech, J.A. and Stewart, G. (1984) Oxygen Depletion of Static Air by Backfill Material at the Thompson
Mine; Mining Science and Technology, Vol. 1, pp. 93–106.
Benzaazoua, M., Marion, P., Picquet, I. and Bussière, B. (2004) The use of pastefill as a solidification and stabilization
process for the control of acid mine drainage, Minerals Engineering, Vol. 17-2, pp. 233–243.
Benzaazoua, M., Belem, T. and Bussière, B. (2002) Chemical factors that influence on the performance of mine
sulphidic paste backfill, Cement and Concrete Research, Vol. 32–7, pp. 1133–1144.
Benzaazoua, M., Belem, T. and Bussière, B. (2001) Mise en évidence du phénomène d’auto-ignition dans les remblais
cimentés, Rapport FUQAT.
Benzaazoua, M. and Belem, T. (2000) Optimization of sulfide-rich paste backfill mixtures for increasing long-term
strength and stability, in Proceedings 5th Conference on Clean Technology for Mining Industry, Santiago, Chile,
M.A. Sánchez, F. Vergara and S.H. Castro (eds), University of Concepción, Vol. I, pp. 343–352.
Benzaazoua, M., Ouellet, J., Servant, S., Newman, P. and Verburg, R. (1999) Research, Cementatious Backfill with
High Sulphur Content, Cement and Concrete, Vol. 29, No. 5, pp. 717–725.
Benzaazoua, M. (1996) Caractérisation physico-chimique et minéralogique de produits miniers sulfurés en vue de la
réduction de leur toxicité et de leur valorisation, thèse de l’Institut National Polytechnique de Lorraine, Nancy,
267 p.
Bernier, L.R. and Li, M. (2003) High temperature oxydation (heating) of sulfidic paste backfill: A mineralogical and
chemical perspective, Sudbury 2003, CD.
Bernier, L. and Li, M. (1998) Comparative analysis of oxidized and unaltered paste backfill specimens from Louvicourt
mine, Internal Technical report prepared for Brunswick mining division, Noranda Inc. Bathurst, New Brunswick.
30 p.
Bertrand, V.J., Monroy, M.G. and Lawrence, R.W. (2000) Weathering characteristics of cemented paste backfill:
mineralogy and solid phase chemistry, in Proceedings 5th International Conference on Acid Rock Drainage
(ICARD), Denver, Colorado, Vol. II, pp. 863–876.
Cruz, R., González, I. and Monroy, M. (2005) Electrochemical characterization of pyrrhotite reactivity under simulated
weathering conditions, Applied Geochemistry, Vol. 20, Issue 1, January 2005, pp. 109–121.
Elberling, B. and Damgaard, L.R. (2001) Microscale measurements of oxygen diffusion and consumption in
subaqueous sulfide tailings, Geochimica and Cosmochimica Acta, Vol. 65, No. 12, pp. 1897–1905.
Elberling, B. and Nicholson, R.V. (1996) Field determination of sulfide oxidation rates in mine tailings, Water
Resources Research, Vol. 32, pp. 1773–1784.
Underground and backfill applications
Paste 2010, Toronto, Canada 173
Elberling, B., Nicholson, R.V., Reardon, E.J. and Tibble, P. (1994) Evaluation of sulphide oxidation rates: laboratory
study comparing oxygen fluxes and rates of oxidation product release, Canadian Geotechnical Journal, Vol. 31,
pp. 375–383.
Elberling, B., Nicholson, R.V. and David, D.J. (1993) Field evaluation of sulphide oxidation rates, Nordic Hydrology,
Vol. 24, pp. 323–338.
Godbout, J. (2010) Influence of pyrrhotite content on the mechanical and chemical behaviour of cemented paste
backfill, University of Quebec in Abitibi-Temiscamingue, Ph.D. Thesis (in preparation).
Gosselin, M. (2007) Étude de l’influence des caractéristiques hydrogéochimiques des résidus miniers réactifs sur la
diffusion et la consommation de l’oxygène, Mémoire de maîtrise, École Polytechnique de Montréal, 246 p.
Liu, Q.K., Bernier, L. and Rosenblum, F. (1999) Preliminary investigation of the possible pastefill selfheating at
Louvicourt Mine, Internal report, 91 p.
Mbonimpa, M., Aubertin, M., Aachib, M. and Bussière, B. (2003) Diffusion and consumption of oxygen in unsaturated
cover materials, Canadian Geotechnical Journal, Vol. 40(5), pp. 916–932.
Mbonimpa, M., Aubertin, M., Dagenais, A-M., Bussière, B., Julien, M. and Kissiova, M. (2002) Interpretation of fields
tests to determine the oxygen diffusion and reaction rate coefficients of tailings and soil covers, Ground and
Water: Theory to Practice, in Proceedings 55th Canadian Geotechnical Conference, Niagara Falls, Ontario,
Canada, October 20–23 2003, pp. 147–154.
Ouellet, S., Bussière, B., Mbonimpa, M., Benzaazoua, M. and Aubertin, M. (2006) Reactivity and mineralogical
evolution of an underground mine sulphidic cemented paste backfill, Minerals Engineering, Vol. 19(5),
pp. 407–419.
Ouellet, S., Bussière, B., Mbonimpa, M., Benzaazoua, M. and Aubertin, M. (2005) Reactivity and mineralogical
evolution of an underground mine sulphidic cemented paste backfill, Minerals Engineering, Vol. 19, Issue 5,
April 2006, pp. 407–419.
Ouellet, S., Bussière, B., Benzaazoua, M., Aubertin, M. and Belem, T. (2003) Sulphide reactivity within cemented paste
backfill: oxygen consumption test results, 56th Annual Canadian Geotechnical Conference and 4th Joint IAH-
CNC and CGS Groundwater Specialty Conference, 29 September – 1 October 2003, Winnipeg, Manitoba,
Comptes-Rendus sur CD.
Philips, M., Hockley, D. and Dawson, B. (2008) Sullivan mine fatalities incident: Initial technical investigation and
findings, in Proceedings Hydrometallurgy 2008, 6th International symposium, Pheonix, August 17–20, 2008.
Rosenblum, F., Nesset, J. and Spira, P. (2001) Evaluation and control of self heating in sulphides concentrates, CIM
Bulletin, Vol. 94, No. 1056, pp. 92–99.
Rosenblum, F. and Spira, P. (1995) Evaluation of hazard from self heating of sulphides rocks, CIM Bulletin, April,
1995, pp. 44–49.
Rosenblum, F., Spira, P. and Konigsmann, K.V. (1982) Evaluation of hazard from sulphide oxidation, In Proceedings
14th International Mineral Processing Congress, Paper IX-2.
Taylor, J.C. and Hinczak, I. (2001) Rietveld made easy: A Practical Guide to the Understanding of the Method and
Successful Phase quantifications.
Tibble, P.A. and Nicholson, R.V. (1997) Oxygen consumption on sulphide tailings and covers: measured rates and
applications, in Proceedings 4th International Conference on Acid Rock Drainage, Vancouver, Canada, Vol. 2,
pp. 647–661.
Influence of pyrrhotite content on the mechanical and chemical behaviour of cemented paste backfill J. Godbout et al.
174 Paste 2010, Toronto, Canada

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