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Co-Disposal of Coal Ash with Mine Tailings in Surface Paste Disposal Practices: A Gold Mining Case Study

Authors: M. L. Dinis, M. C. Vila, A. Fiúza, A. Futuro, C. Nunes

Abstract:

The present paper describes the study of paste tailings prepared in laboratory using gold tailings, produced in a Finnish gold mine with the incorporation of coal ash. Natural leaching tests were conducted with the original materials (tailings, fly and bottom ashes) and also with paste mixtures that were prepared with different percentages of tailings and ashes. After leaching, the solid wastes were physically and chemically characterized and the results were compared to those selected as blank – the unleached samples. The tailings and the coal ash, as well as the prepared mixtures, were characterized, in addition to the textural parameters, by the following measurements: grain size distribution, chemical composition and pH. Mixtures were also tested in order to characterize their mechanical behavior by measuring the flexural strength, the compressive strength and the consistency. The original tailing samples presented an alkaline pH because during their processing they were previously submitted to pressure oxidation with destruction of the sulfides. Therefore, it was not possible to ascertain the effect of the coal ashes in the acid mine drainage. However, it was possible to verify that the paste reactivity was affected mostly by the bottom ash and that the tailings blended with bottom ash present lower mechanical strength than when blended with a combination of fly and bottom ash. Surface paste disposal offer an attractive alternative to traditional methods in addition to the environmental benefits of incorporating large-volume wastes (e.g. bottom ash). However, a comprehensive characterization of the paste mixtures is crucial to optimize paste design in order to enhance engineer and environmental properties.

Keywords: Coal ash, gold tailings, paste, surface disposal.

Digital Object Identifier (DOI): doi.org/10.5281/zenodo.1125525

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References:


[1] European Commission, “Mining Waste”, Retrieved 08 June 2016 from http://ec.europa.eu/environment/waste/mining/.
[2] WISE Uranium Project, “Tailings Dam Safety, Chronology of major tailings dam failures”, Retrieved 18 March 2016 from http://www.wise-uranium.org/mdaf.html.
[3] Down C. G., and Stocks J. (a), “Environmental impacts of mining”, in Applied Science Publishers Ltd., 1977, 371 pp.
[4] Down C. G., and Stocks J. (b), “Environmental problems of tailings disposal”, in Mining Magazine, vol. 137:1, 1977, pp. 25-33.
[5] Ritcey, G. M., “Tailings Management: Problems and Solution in the Mining Industry”, Elsevier, Amsterdam, The Netherlands, Eds., 1989, 970 pp.
[6] Johnson D. B., “Chemical and microbiological characteristics of mineral spoils and drainage waters at abandoned coal and metal mines”, in Water Air Soil Pollution, vol. 3, 2003, pp. 47– 66.
[7] Johnson D. B., and Hallberg K.B, “Acid mine drainage remediation options: a review”, in Sci. Total Environ., vol. 38, 2005, pp. 3–14.
[8] Jacobs J. A., Lehr J. H., and Testa S. M., “Acid Mine Drainage, Rock Drainage, and Acid Sulfate Soils: Causes, Assessment, Prediction, Prevention, and Remediation”, John Wiley & Sons, Eds, 2014, 504 pp.
[9] Benzaazoua M., Perez P., Belem T., and Fall M., “A laboratory study of the behaviour of surface paste disposal”, in Proc. 8th Minefill Symposia, Minefill, Beijing, China, 2004, pp. 180-192.
[10] Engels J., and Dixon-Hardy D., “Tailings impoundments – A growing environmental concern”, in Geotechnical and Environmental Aspects of Waste Disposal Sites, R. W. Sarsby, and A. J. Felton, London, 2007, pp. 233-246.
[11] Verburg, R. B. M., “Use of Paste Technology for Tailings Disposal: Potential Environmental Benefits and Requirements for Geochemical Characterization”, in Proc. International Mine Water Association Meetings, IMWA, Belo Horizonte, Brazil, 2011, pp. 1-13.
[12] Fourier A. B., “Perceived and realized benefits of paste and thickened tailings for surface deposition”, in Proc. Paste 2012, R. J. Jewell, A. B. Fourie, and A. Paterson, Eds, Sun City, South Africa, 2012, pp. 53-64.
[13] Tariq A., and Yanful E. K., “A review of binders used in cemented paste tailings for underground and surface disposal practices”, in Journal of Environmental Management, vol. 131, 2013, pp. 138-149.
[14] Brackebusch F. W., “Basics of paste backfill systems”, in Mining Engineering, October, 1995, pp. 1175 – 1178.
[15] Roy W. R., and Griffin, R. A., “A proposed classification system for coal fly ash in multidisciplinary research”, in J. Environ. Qual., vol. 11, pp. 563 - 568.*
[16] Bayat O., “Characterization of Turkish fly ashes” in Fuel, vol. 77 (9/10), 1998, pp. 1059–1066.
[17] Ciccu R., Ghiani M., Serci A., Fadda S., Peretti R., Zucca A., “Heavy metal immobilization in the mining-contaminated soils using various industrial wastes”, in Mineral Engineering, Vol. 16, 2003, pp. 187–192.
[18] Yeheyis M. B., Shang J. Q., and Yanful E. K., “Beneficial utilization of coal fly ash as Acid mine drainage barrier, in: Proc. The 60th Canadian Geotechnical Conference, Ottawa, Canada, 2007.
[19] Lee J. K., Shang J. Q., and Jeong S., “Thermo-mechanical properties and microfabric of fly as-stabilized gold tailings”, in Journal of Hazardous Materials, vol. 276, 2014, pp. 323-331.
[20] Vadapalli V. R. K., Klink M. J., Etchebers O., Petrik L. F., Gitari W., White R. A., Key D., and Iwuoha E., “Neutralisation of acid mine drainage using fly ash, and strength development of the resulting solid residues”, in South African Journal of Science, vol. 104, 2008, pp. 317–322.
[21] Longo S., “Paste and Ash Systems: Case Studies”, in Proc. World of Coal Ash (WOCA) Conference, Nasvhille, TN, 2015.
[22] Yeheyis M. B., Shang J. Q., and Yanful E. K., “Characterization and environmental evaluation of Atikokan coal fly ash for environmental applications”, in J. Environ. Eng. Sci., vol. 7 (5), 2008, pp. 481–498.
[23] JOE, “The processing and exploitation, for economic and environmental purposes, of industrial and mining waste deposits in the European Union”, JOE - Official Journal of the European Union, (2012/C 24/03), pp. 24/11-24/17.
[24] Black C. A., Methods of Soil Analysis: Part II Chemical and Biological Properties, Nº. 9 (Part 2), Second Edition, R. C. Dinauer Managing Editor, American Society of Agronomy, Madison, Wisconsin, USA, 1965, pp. 914-926.
[25] Campbell D. E., “Energy analysis of human carrying capacity and regional sustainability: An example using the state of Maine”, in Environ Monitoring and Assessment, vol. 51(1-2), 1998, pp. 83–94.
[26] Mahlaba J. S., and Pretorius, P. C., “Exploring paste technology as a co disposal option for fly ash and brines”, in Proc. Paste 2006, 9th International Seminar on Paste and Thickened Tailings, Limerick, Ireland, 2006.
[27] Chancey R. T., Stutzman P., Juenger M. C. G., and Fowler D. W., “Comprehensive phase characterization of crystalline and amorphous phases of a Class F fly ash”, in Cement and Concrete Research, vol. 40, 2010, pp. 146–156.
[28] Doucet D., Girard D., Grondin L. P., and Matte P., “Technical Report on the Mineral Resource and Mineral Reserve Estimate and the Suuri Extension Project, Kittila Mine, Finland”, Prepared for Agnico-Eagle Mines Limited, Toronto, Ontario, Canada, 2010, 176 pp.
[29] Madsen P. A., and Mulligan D. R., “Effect of NaCl on emergence and growth of a range of provenances of Eucalyptus citriodora, Eucalyptus populnea, Eucalyptus camaldulensis and Acacia salicina”, in Forest Ecol Manag, vol. 228, 2006, pp. 152–159.
[30] Gozzard E., Vink S., Nanjappa V., and Moran C. J., “Salt dissolution dynamics on surface mine spoils”, in Proc. of Water in Mining, Perth, Australia, 2009, pp. 233–240.
[31] Huang L., Baumgartl T., and Mulligan D., “Is rhizosphere remediation sufficient for sustainable revegetation of mine tailings?” Ann Bot-London, vol. 110, 2012, pp. 223–238.
[32] Belem T., and Benzaazoua M., “An overview on the use of paste backfill technology as a ground support method in cut-and-fill mines”, in Proc. of the 5th Int. Symp. on Ground support in Mining and Underground Construction, Villaescusa & Potvin, Tayler & Francis Group, London, Eds, Perth, Australia, 2004, pp. 637 – 650.
[33] Yilmaz E., Belem T., Benzaazoua M., Kesimal A., Ercikdi B., and Cihangi F., “Use of high-density paste backfill for safe disposal of copper/zinc mine tailings”, in Gospod.Surowcami. Min., vol. 27, 2011, 81-94.
[34] Qi T., Feng G., Zhang Y., Guo J., and Guo Y., “Effects of Fly Ash Content on Properties of Cement Paste Backfilling”, in Journal of Residuals Science & Technology, vol. 12, No 3, 2015, pp. 113-142.
[35] Pashias N., Boger D. V., Summers J., Glenister D. J., “A 50 cent rheometer for yield stress measurements”, in J. Rheol., vol. 40(6), 1996, pp. 1179–1189.
[36] Schowalter W. R., and Christensen G., “Toward a rationalization of the slump test for fresh concrete: comparisons of calculations and experiments”, in J. Rheol., vol. 42(4), 1998, pp. 865–870.
[37] Boger D. V., Scales P. J., and Sofra F., “Paste and thickened tailings and the impact on the development of new rheological techniques”, in Proc. Paste 2008, 11th Seminar on Paste and Thickened Tailings, Kasane, Botswana, 2008.