Authors: Zarassi, A; Hassani, FP


DOI https://doi.org/10.36487/ACG_rep/1404_20_Zarassi

Cite As:
Zarassi, A & Hassani, FP 2014, 'An investigation into the effect of cementation on self-heating of backfill', in Y Potvin & T Grice (eds), Mine Fill 2014: Proceedings of the Eleventh International Symposium on Mining with Backfill, Australian Centre for Geomechanics, Perth, pp. 259-270, https://doi.org/10.36487/ACG_rep/1404_20_Zarassi

Download citation as:   ris   bibtex   endnote   text   Zotero


Abstract:
The use of high sulphide content mine tailings as backfill could pose technical and environmental challenges during mining operations or the post-mining cycle. This paper describes one of these challenges: the self−heating of high sulphide content backfills, and proposes a mitigation method involving the use of different amounts of binders and additives. Tailings rich in sulphide minerals, and in particular pyrrhotite, may self-heat, defined as the spontaneous oxidation of materials resulting in excessive heat generation. This phenomenon has led to mine fires, elevated toxic gas levels, oxygen depletion in the stopes, acid mine drainage and even mine closure in some cases. The self-heating cycle can be described in three stages, defined by increasing heating rates: stage A from ambient temperature to 100°C, at which point free moisture is driven off; stage B continues to 350-400°C (the ignition point of sulphides) if sustained by the reactions; and Stage C starts at the ignition point, and effectively represents roasting of the material. A unique apparatus for measuring stage A and stage B self-heating rates, which was originally developed at the Noranda Technology Centre in the 1980s, and now resides at McGill University, was used for this work. Results are reported as self-heating capacity (SHC) for backfill samples (joules/gram). Interpretation of SHC values is done by using a risk-assessment chart that delineates five regions of increasing risk. The experimental program reported here involved adding different amounts of cement, slag and sodium silicate to high-pyrrhotite tailings to investigate the mitigating effect of cementation on self-heating. Findings clearly demonstrate that cementation significantly reduces the SHC values of backfill samples and effectively removes their associated data points from the high risk region in the assessment chart. In addition, the SHC values are highly sensitive to the amount of binders and additives added to the backfill.

References:
Anderson, AL 1930, ‘The incipient oxidation of galena’, Economic Geology, vol. 25, no. 5, pp. 528-42.
Bernier, LR & Li, M 2003, ‘High temperature oxidation (heating) of sulfidic paste backfill: A mineralogical and chemical perspective’, in G. Spiers (ed.), Proceedings of the 3rd Mining and the Environment Conference, Canadian Land Reclamation Association, Calgary, on CD-ROM.
Enderlin, WI 1973, ‘Evaluating underground heat sources in deep mines’, master thesis, Montana College of Mineral Science and Technology.
Farnsworth, DJM 1977, ‘Introduction to and background of sulphide fires in pillar mining at the Sullivan mines’, CIM Bulletin, vol. 70, no. 782, pp. 65-71.
Good, BH 1977, ‘The oxidation of sulphide minerals in the Sullivan mine’, CIM Bulletin, vol. 70, no. 782, pp. 83-8.
Greenwood, N & Earnshaw, A 1997, Chemistry of the elements, 2nd edn, Butterworth-Heinemann, Oxford, Oxfordshire.
Hassani, FP & Bois, D 1992, Economic and technical feasibility for backfill design in Quebec underground mines, Final report 1/2, Canada-Quebec Mineral Development Agreement, Research & Development in Quebec Mines, Contract no EADM 1989−1992, File-no. 71226002.
Hassani, FP & Archibald, JF 1998, Mine backfill, Canadian Institute of Mining, Metallurgy and Petroleum, Montreal, Quebec, on CD−ROM.
Hassani, F, Razavi, M & Isagon, I 2007, ‘Strength Characteristics of Sodium Silicate-fortified Sand Pastefill’, CIM Bulletin, vol. 2, no. 5, pp. 9.
Kermani, M, Hassani, F & Isagon, I 2009, ‘The effect of sodium silicate concentration and pulp density on the strength of gelfill’, in RK Singhal, A Mehrotra, K Fytas and H Ge (eds), Proceedings of the 18th International Symposium on Mine Planning and Equipment Selection, Curran Associates, Inc., Red Hook, pp. 439-448, on CD-ROM.
Klassen, VI & Mokrousov, VA 1963, An introduction to the theory of floatation, Butterworth Publishers, Oxford, Oxfordshire.
Lukaszewski, GM 1969, ‘Natural oxidation and the reaction of ANFO explosives in mineral sulphides at Mount Isa Mines Ltd.’, in MJ Jones (ed.), Proceedings of the 9th Commonwealth Mining and Metallurgical Congress, Institution of Mining and Metallurgy, London, pp. 33-49.
Navarra, A, Graham, JT, Somot, S, Ryan, DH & Finch, JA 2010, ‘Mössbauer quantification of pyrrhotite in relation to self-heating’, Minerals Engineering, vol. 23, no. 8, pp. 652-8.
Ninteman, DJ 1978, ‘Spontaneous oxidation and combustion of sulphide ores in underground mines: A literature survey’, Information circular, U.S. Department of Interior, Bureau of Mines.
O’Brien, MM & Banks, HR 1926, ‘The Sullivan mine and concentrator: A review of 3 years progress’, CIM Magazine, vol. 29, pp. 100−21.
Payant, RA 2010, ‘The self-heating of sulphide mixtures’, master thesis, McGill University.
Payant, RA & Finch, JA 2010, ‘The self-heating of sulphide mixtures’, Canadian Metallurgical Quarterly, vol 49, no 4, pp. 429-434.
Rosenblum, F & Spira, P 1981, ‘Self-heating of sulphides’, Proceedings of the 13th Annual Meeting of the Canadian Mineral Processors, Canadian Institute of Mining, Metallurgy and Petroleum, Montreal, pp. 34-49.
Rosenblum, F & Spira, P 1995, ‘Evaluation of hazard from self-heating of sulphide rock’, CIM Bulletin, vol. 88, no. 989, pp. 44-9.
Rosenblum, F, Nesset, JE & Spira, P 2001, ‘Evaluation and control of self-heating in sulphide concentrates’, CIM Bulletin, vol. 94, no. 10,569, pp. 92-9.
Somot, S & Finch, JA 2010, ‘Possible role of hydrogen sulphide gas in self-heating of pyrrhotite-rich materials’, Mineral Engineering, vol. 23, no. 2, pp. 104-10.
Spearing, AJS & Smart, RM 1990, ‘The Potential benefits of (silicated) cemented backfill system’, in DAI Ross-Watt and PDK Robinson, Proceedings of the International Deep Mining Conference, vol 2: Technical challenges in deep level mining, South African Institute of Mining and Metallurgy, Johannesburg.
Wang, X, Rosenblum, F, Nesset, JE, Somot, S & Finch, JA 2009, ‘Oxidation, weight gain and self-heating of sulphides’, in R Henderson (ed.), Proceedings of the 41st Annual Meeting of the Canadian Mineral Processors, Canadian Institute of Mining, Metallurgy and Petroleum, Montreal, pp. 63-77.
Wu, C & Li, Z 2005, ‘A simple method for predicting the spontaneous combustion potential of sulphide ores at ambient temperature’, Mining Technology, Transactions of IMM, vol. 114, no. 2, pp. 125-8.
Zarassi, A, Hassani, F, Nesset, J, Rosenblum, F & Isagon, I 2011, ‘Self-heating and mitigating methods for minefill’, in HJ Ilgner, Proceedings of the 10th International Symposium on Mining with Backfill, South African Institute of Mining and Metallurgy, Johannesburg, pp. 377-82.




© Copyright 2021, Australian Centre for Geomechanics (ACG), The University of Western Australia. All rights reserved.
Please direct any queries or error reports to repository-acg@uwa.edu.au