INVESTIGATION OF THE EFFECTS OF CLASS C FLY ASH CEMENT SUBSTITUTION ON STRENGTH IN CEMENTED PASTE BACKFILL

Year 2020, Volume: 8 Issue: 2, 479 - 488, 25.06.2020

Serkan Tüylü

https://doi.org/10.21923/jesd.680355

Abstract

Cemented Paste Backfill (CPB) Method is an important tailings management system that can provide support against collapses due to the roof loads, as well as enabling storage possibilities of high amount of process tailings at the underground. Therefore, it gains important that the paste material created in this system gets the maximum strength value depending on the time. For this purpose, the optimum mixing ratios of the paste material should be determined with minimum costs. The main purpose of this study is to determine the additive rate that it can substitute for cement in order to reduce the amount of cement, which constitutes one of the high costs of paste backfill. Firstly, the solid content of the paste material was determined as 80% according to the slump tests, and then CPB reference samples were prepared. By taking the solid content of 80% fixed, 3-11% cement was used, it was determined that the strength of the samples containing 9% and 11% cement gave sufficient strength values. Subsequently, 20-30-40 and 50% of these cement ratios were substituted with fly ash samples and their effects on the strength of CPB were examined over the curing times of 28, 56 and 90 days. As a result, it put forth that, according to reference samples, fly ash substitution of up to 30% can use in the paste mixtures with 9% cement ratio, especially in curing periods of 56 and 90 days. In addition, up to 50% fly ash substitution can use instead of cement in 11% cement.

Keywords

Pb-Zn Tailings, Cemented Paste Backfill (CPB), Fly Ash, Strength

ÇİMENTOLU MACUN DOLGUDA C SINIFI UÇUCU KÜLÜN ÇİMENTO YERİNE İKAMESİNİN DAYANIMA OLAN ETKİLERİNİN İNCELENMESİ

Abstract

Çimentolu macun dolgu (ÇMD) yöntemi, öncelikle yüksek miktarda proses atıklarının yeraltında depolanabilmesine imkan vermesinin yanında tavan yüklerine bağlı göçüklere karşı da destek sağlayan önemli bir atık yönetimi sistemidir. Dolayısıyla bu sistem içerisinde oluşturulan macun malzemenin zamana bağlı olarak alacağı maksimum dayanım değeri önem kazanmaktadır. İstenilen dayanımın sağlanabilmesi için, macun malzemenin optimum karışım oranlarının en az maliyetle belirlenmesi gerekmektedir. Bu kapsamda, macun dolgudaki yüksek maliyetlerden birini oluşturan çimento miktarını düşürmek için Tufanbeyli uçucu külünün çimento yerine ikame edilebileceği yaklaşık katkı oranının belirlenmesi amaçlanmıştır. Öncelikle çökme deneylerine göre macun malzemedeki katı içeriği %80 olarak belirlenmiş ve buna göre ÇMD referans numuneleri hazırlanmıştır. %80 katı içeriği sabit tutularak %3-11 arası çimento kullanımı gerçekleştirilmiş, bunlardan %9 ve %11 çimento içerikli numunelerin dayanımlarının yeterli dayanım değerleri verdiği tespit edilmiştir. Daha sonra bu çimento oranlarının da %20-30-40 ve 50’si oranında çimento yerine uçucu kül ikameli numuneler hazırlanmış ve 28, 56 ve 90 günlük kür sürelerine göre de macun dolgu malzemesinin dayanımına etkileri incelenmiştir. Sonuç olarak, referans numunelere göre %9 çimentonun %30’una kadar uçucu kül ikamesinin özellikle 56 ve 90 günlük kür sürelerinde ve %11 çimentonun %50’sine kadar uçucu kül ikameli karışımların ÇMD karışımında kullanılabileceği ortaya konulmuştur.

Keywords

Pb-Zn Atıkları, Çimentolu Macun Dolgu (ÇMD), Uçucu Kül, Dayanım

References

• Abdul-Hussain N. and Fall M., 2011. Unsaturated hydraulic properties of cemented tailings backfill that contains sodium silicate. Eng Geol 123(4):288–301.
• Adiguzel D. and Bascetin A., 2019. The investigation of effect of particle size distribution on flow behavior of paste tailings. Journal of Environmental Management 243 (2019) 393–401.
• Alkaya, D., 2009. Uçucu Küllerin Zemin İyileştirmesinde Kullanılmasının İncelenmesi. Yapı Teknolojileri Elektronik Dergisi Cilt: 5, No: 1, 2009 (61-72).
• ASTM C39., 2018. Standard Test Method for Compressive Strength of Cylindrical Concrete Specimens, ASTM International, West Conshohocken, PA.
• ASTM C143., 2015. Standard Test Method for Slump of Hydraulic-Cement Concrete, ASTM International, West Conshohocken, PA.
• ASTM C618., 2019. Standard Specification for Coal Fly Ash and Raw or Calcined Natural Pozzolan for Use in Concrete, ASTM International, West Conshohocken, PA.
• Benzaazoua, M., Ouellet, J., Servant, S., Newman, P., Verburg, R., 1999. Cementitious backfill with high sulphur content: physical, chemical and mineralogical characterization. Cem. Concr. Res. 29 (5), 719 - 725.
• Benzaazoua, M., Belem T. and Bussie`re B., 2002. Chemical factors that influence the performance of mine sulphidic paste backfill, Cement and concrete research, 32: 12.
• Belem, T. and Benzaazoua, M., 2008. Design and application of underground mine paste backfill technology. Geotechnical and Geological Engineering, 26(2), 147-174.
• Brackebusch, F.W., 1994. Basics of paste backfill systems, Mining Engineering, 46, 1175–8.
• Cihangir, F., Ercikdi B., Kesimal A., Deveci H. and Erdemir F., 2015. Paste backfill of high-sulphide mill tailings using alkali-activated blast furnace slag: effect of activator nature, concentration and slag properties, Minerals engineering, 83: 117-127.
• Clark CC, Vickery JD, Backer RR, 1995. Transport of total tailings paste backfill: results of full-scale pipe test loop pumping tests. Report of investigation, RI 9573, USBM, 37 pp.
• Dong, Q., Liang, B., Jia, L., Jiang L., 2019. Effect of sulfide on the long-term strength of lead-zinc tailings cemented paste backfill. Construction and Building Materials 200 (2019) 436–446.
• Eker, H., 2019. Metalik Proses Artıklarının Macun Dolgu Yöntemi ile Depolanmasında Uygun Tasarım Parametrelerinin Belirlenmesi, İstanbul Üniversitesi-Cerrahpaşa Lisansüstü Eğitim Enstitüsü, Maden Mühendisliği Anabilim Dalı, 2019.
• Erçıkdı, B., Cihangir, F., Kesimal, A., Deveci, H., ve Alp, I., 2009. Utilization of industrial waste products as pozzolanic material in cemented paste backfill of high sulphide mill tailings, Journal of Hazardous Materials, 168, 848–856.
• Fall M, Benzaazoua M, Ouellet S, 2005. Experimental characterization of the effect of tailings fineness and density on the quality of cemented paste backfill. Miner Eng 18(1):41–44
• Fall, M., Benzaazoua M. and Saa, E. G., 2008. Mix proportioning of underground cemented tailings backfill, Tunnelling and underground space technology, 23(1): 80-90.
• Fall, M., Adrien, D., Célestin J. C., Pokharel M. and Touré, M., 2009. Saturated hydraulic conductivity of cemented paste backfill, Minerals engineering, 22(15): 1307-1317.
• Fall, M. and Pokharel, M., 2010. Coupled effects of sulphate and temperature on the strength development of cemented tailings backfills: portland cement-paste backfill, Cement and concrete composites, 32(10): 819-828.
• Ghirian, A. and Fall, M., 2015. Coupled behavior of cemented paste backfill at early ages, Geotechnical and geological engineering, 33(5): 1141-1166.
• Ghirian, A. and Fall, M., 2016. Long-term coupled behaviour of cemented paste backfill in load cell experiments, Geomechanics and geoengineering, 11(4): 237-251.
• Gorakhki, M.H. and Bareither, C.A., 2018. Compression Behavior of Mine Tailings Amended with Cementitious Binders, Geotech Geol Eng (2018) 36:27–47.
• Hassani F, Archibald J., 1998. Mine backfill. In: Canadian Institute of Mine, Metallurgy and Petroleum, Published on CD-ROM Proceedings, Canada, 263p.
• Hassani, F.P., Nokken, M.R., Annor, A.B., 2007. Physical and mechanical behaviour of various combinations of mine fill materials, CIM Bull. 2 (3), 72.
• Hefni, M. A., 2014. An investigation into the develpoment and potential of foam minefill, PhD thesis, McGill University.
• Huang S., Xia K. And Qiao L., 2011. Dynamic tests of cemented paste backfill: effects of strain rate, curing time, and cement content on compressive strength. J Mater Sci (2011) 46:5165–5170.
• Jiang, H., M. Fall and L. Cui, 2017. Freezing behaviour of cemented paste backfill material in column experiments, Construction and building materials, 147: 837-846.
• Kesimal, A., Yılmaz, E., Erçıkdı, B., 2004. Evaluation of paste backfill test results obtained from different size slumps with varying cement contents for sulphur rich mill tailings, Cem. Concr. Res. 34 (10), 1817e1822.
• Koohestani, B., Bussière, B., Belem T.and Koubaa, A., 2017. Influence of polymer powder on properties of cemented paste backfill, International journal of mineral processing, 167: 1-8.
• Li T, Singh U, Coxon J, Grice TG, Sainsbury D, 2002. Development and application of paste fill using dry tailings. First International Seminar on Deep and High Stress Mining, Perth, 10 pp
• Li, W. and Fall M., 2016. Sulphate effect on the early age strength and self-desiccation of cemented paste backfill, Construction and building materials, 106: 296-304.
• Meggyes, T. and Debreczeni, A., 2006. Paste technology for tailings management, Land Contamination& Reclamation, 14 (4), 2006 EPP Publications Ltd.
• Newman, P., Cadden, A., White, R., 2001. Paste - The Future of Tailings Disposal? Securing the Future, International Conference on Mining and the Environment. June 25 - July 1, Skelleftea, Sweden, pp.594 – 603.
• Ouattara, D., Yahia, A., Mbonimpa, M., & Belem, T., 2017. Effects of superplasticizer on rheological properties of cemented paste backfills. International Journal of Mineral Processing, 161, 28-40.
• Ouattara, D., Mbonimpa, M., Yahia, A., Belem, T., 2018. Assessment of rheological parameters of high density cemented paste backfill mixtures incorporating superplasticizers. Construction and Building Materials. Volume 190, 30 November 2018, Pages 294-307.
• Ramlochan, T., Thomas, M., and Hooton, R., 2004. The effect of pozzolans and slag on the expansion of mortars cured at elevated temperature: Part II: Microstructural and microchemical investigations, Cement and Concrete Research, 34(8), 1341-1356.
• Tariq, A. and Nehdi, M., 2007. Developing durable paste backfill from sulphidic tailings, Proceedings of the institution of civil engineers - waste and resource management, 160(4): 155-166.
• Tariq, A., and Yanful, E. K., 2013. A review of binders used in cemented paste tailings for underground and surface disposal practices, Journal of environmental management, 131, 138-149
• TÇMB, 2009. Türkiye’deki Uçucu Küllerin Sınıflandırılması ve Özellikleri. 4. Baskı Temmuz 2009. ISBN 975-8136-18-6
• Tüylü, S. 2016, Maden tesis atıklarının yerüstünde depolanmasında en uygun tasarım koşullarının belirlenmesi, İstanbul Üniversitesi, Fen Bilimleri Enstitüsü, Maden Mühendisliği Anabilim Dalı, 2016.
• TS EN 196-6, 2010. Çimento deney yöntemleri - Bölüm 6: İncelik tayini.
• Wang Y., Wu A., Wang S., Wang H., Yang L., Wang Y. and Ruan Z.e., 2017. Correlative mechanism of hydraulic-mechanical property in cemented paste backfill, Journal of
• Wuhan university of technology-mater. sci. ed., 32(3): 579-585.
• Wu A., Wang Y., Wang H., Yin S. and Miao X., 2015. Coupled effects of cement type and water quality on the properties of cemented paste backfill, International journal of mineral processing, 143: 65-71.
• Yilmaz, E., Belem, T., Bussière B. and Benzaazoua M., 2011. Relationships between microstructural properties and compressive strength of consolidated and unconsolidated cemented paste backfills, Cement and concrete composites, 33(6): 702-715.
• Yilmaz, E., Belem, T., Benzaazoua M., 2015. Specimen size effect on strength behavior of cemented paste backfills subjected to different placement conditions. Engineering Geology 185 (2015) 52–62.
• Yılmaz, T. Erçıkdı, B. Cihangir, F. 2017. Yüksek fırın cürufu ve perlit ikamesinin çimentolu macun dolgunun mekanik ve mikroyapı özelliklerine etkisi, Çukurova Üniversitesi Mühendislik Mimarlık Fakültesi Dergisi, 32(2), ss. 239-251, Haziran 2017.
• Yilmaz, E., 2018. Stope depth effect on field behaviour and performance of cemented paste backfills. International Journal of Mining, Reclamation and Environment, 32:4, 273-296