Optimization study of blasting operations in Roşia Poieni open pit mine, Romania
1University of Petrosani, Petrosani, 332006, Romania
Min. miner. depos. 2021, 15(4):43-55
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Purpose. Drilling-blasting technology is one of the simplest and most often used techniques in open pit mining. This allows the excavation of a large volume of rock and useful mineral substance. The operation of blasting using the energy of explosives plays an important role in open pit exploitation, being also the key element of the blasting process through which a corresponding granulometry is obtained. This operation is a part of a series of interdependent operations, in the sense that each operation determines a certain result that will be an important element for the next operation that takes place in the working face. Consequently, the blasting operation with explosives should not be considered as an independent act. A global approach to the entire production technological process including blasting is required.
Methods. In the optimization study, the basic method consisted in the analysis of the blasting operations performed at the drilling diameter of 250 mm (blasting technology used in Roşia Poieni open pit mining) and simulation of the excavation of the same rock volume, with the optimization of the explosive charge distribution at two other drilling diameters: 200 and 150 mm.
Findings. The main problems when shooting 250 mm dia holes are caused by the length of the tamping in the mineralized rock that leads to the appearance of blocks with dimensions which are maximum allowed in the crusher tank (1.2-1.3 m). That is why discontinuous loads with intermediate tamping are used – the method that successfully limits their number. In order to obtain a granulometry corresponding to the primary crushing operation, which will allow to decrease the crushing costs, it is necessary to use smaller drilling diameters, but with productivity high enough to ensure the optimal development of the extraction process.
Originality. Based on the performed study, it is recommended to use the discontinuous load, preserving the total length of the explosive charge. In the zones where the rocks have a Protodiakonov coefficient f > 6.5, it is recommended to apply an appropriate drilling diameter (150-200 mm) and use the intermediate tamping at 2-3 m length to limit the upper stemming area to a maximum of 7 m (to limit or eliminate the occurrence of oversized blocks).
Practical implications. The research results will enhance the geometric and safety factors of the operation, limiting the explosion effect on the massif and the environment and reducing the total costs of the cutting operation. The cost of explosives and initiating materials can be reduced by using a smaller quantity of explosive gels in a dry environment (12-18 kg/hole), the difference in the explosive charge length being completed with AM 1.
Keywords: open pit exploitation, drilling-blasting, andesite, explosive, blasting borehole, optimization
- Langefors, U., & Kihlstrom, B. (1963). The modern technics of rock blasting. New York, United States: John Wiley.
- Böyte, A., & Zlăgnean, F. (1998). Stability of slopes made of hard rocks. Deva, Romania: Infomin Publishing House.
- Gabolde, G., & Nguyen, J.-P. (1999). Drilling data handbook. Paris, France: Editions Technip.
- Adam, T., Bourgoyne, Jr., Martin, E., Chenevert, K.K., Millheim, F.S., & Young, Jr. (2007). Applied drilling Engineering. London, United Kingdom: Society of Petroleum Engineers.
- Hartman, H.L., & Mutmansky, J.M. (2002). Introductory mining engineering. New York, United States: John Wiley & Sons.
- Aler, J., Du Mouza, J., & Arnould, M. (1995). Measurement of the fragmentation efficiency of rock mass blasting and its mining applications. International Journal of Rock Mechanics and Mining Sciences & Geomechanics Abstracts, 33(2), 125-139 https://doi.org/10.1016/0148-9062(95)00054-2
- Cook, M.A. (1974). The science of industrial explosives. Salt Lake City, United States: IRECO Chemicals.
- Fodor, D. (2008). Open pit exploitation of useful minerals substances and rock deposits. Deva, Romania: Corvin Publishing House.
- Tat, S., Zaporojan, M., & Fissgus, M. (1985). Explosives and blasting technique in industry. Bucureşti, Romania: Technical Publishing House.
- Hamdi, E., & Du Mouza, J. (2005). Methodology for rock mass characterisation and classification to improve blast results. International Journal of Rock Mechanics and Mining Sciences, 42(2), 177-194. https://doi.org/10.1016/j.ijrmms.2004.07.005
- Sen, G.C. (1995). Blasting technology for mining and civil engineers. Sydney, Australia: University of New South Wales Press.
- Zare, S., & Bruland, A. (2007). Progress of drill and blast tunnelling efficiency with relation to excavation time and costs. Underground Space – the 4th Dimension of Metropolises. London, United Kingdom: Taylor & Francis Group.
- Andrievsky, A.P., & Akhpashev, B.A. (2017). Improvement of rock fragmentation by distributed charge blasting. Journal of Mining Science, (53), 253-258. https://doi.org/10.1134/S1062739117022080
- Persson, P.A., Holmberg, R., & Lee, J. (2000). Rock blasting and explosives engineering. New York, United States: CRC Press.
- Fleurisson, J-A. (2001). Structures géologiques et stabilité des pentes dans les massifs rocheux: Description, analyse et modélisation. Revue Française de Géotechnique, (95/96), 103-116. https://doi.org/10.1051/geotech/2001095103
- Luz-Deinny, C.H. (2006). Optimisation des tirs à l’explosif et de la chaîne de production dans les carrières de granulats, application à la carrière Hélary de Ruvernison (Morlaix, France). Paris, France: ENSMP-CGI, CESECO.
- Hustrulid, W. (1999). Blasting principles for open pit mining. Volume 2: Theoretical Foundations. Rotterdam, The Netherlands: Balkema.
- Mertuszka, P., Szumny, M., Fulawka, K., & Nikolov, S. (2020). Field evaluation of mine blasting efficiency. SWS Journal of Earth and Planetary Sciences, (2), 1-16. https://doi.org/10.35603/eps2020/issue2.01
- Bitimbaev, M.Z., Krupnik, L.A., Aben, E.K., & Aben, K.K. (2017). Adjustment of backfill composition for mineral mining under open pit bottom. Gornyi Zhurnal, (2), 57-61. https://doi.org/10.17580/gzh.2017.02.10
- Toderaş, M. (2002). The effect of the explosion on the environment. Deva, Romania: Bibliofor Publishing House.
- Konya, C.J., & Walter, E.J. (1991). Rock blasting and overbreak control. No. FHWA-HI-92-001. Washington, United States: Federal Highway Administration.
- Onyelowe, K.C., Bui Van, D., Orji, F., Nguyen Van, M., Igboayaka, C., & Ugwuanyi, H. (2018). Exploring rock by blasting with gunpowder as explosive, aggregate production and quarry dust utilization for construction purposes. Electronic Journal of Geotechnical Engineering, (23), 447-456.
- Yassien, M.A., Sayed, M.A., Boghdady, G.Y., Ali, M.A., & Mohamed, A.S. (2020). Experimental research into the effect of some operation factors and rock properties on the rate of penetration. Mining of Mineral Deposits, 14(1), 36-43. https://doi.org/10.33271/mining14.01.036
- Da Gamma, D., & Jimeno, C. (1993). Rock fragmentation control for blasting cost minimisation and environmental impact abatement. Proceedings of the 4th International Symposium on Rock Fragmentation by Blasting. Vienna, Austria: Balkema.
- Bhandari, S. (1997). Engineering rock blasting operations. Rotterdam, The Netherlands: Brookfield.
- Kılıç, A.M., Yasar, E., Erdogan, Y., & Ranjith, P.G. (2009). Influence of rock mass properties on blasting effciency. Scientific Research and Essays, (4), 1213-1224.
- Krasnovskii, A.A., Mirenkov, V.E., & Shutov, V.A. (2006). Studies on fracture of rock blocks. Journal of Mining Science, (42), 105-112. https://doi.org/10.1007/s10913-006-0036-5
- Adebayo, B., & Umeh, E.C. (2007). Influence of some rock properties on blasting performance: A case study. Journal of Engineering and Applied Sciences, (2), 41-44.
- Thornton, D., Kanchibolta, S., & Brunton, I. (2002). Modelling the impact and blast design variation on blast fragmentation. International Journal for Blasting and Fragmentation, 6(2), 169-188. https://doi.org/10.1076/frag.18.104.22.16863