Abstract
Operations planning and management of a large open pit mine is an enormous and complex task, particularly for mines having long life. The long-term planning of open pit mine is a dynamic process and should be reviewed periodically for enhancing the NPV and life of mine. Pit optimization through soft computing can be gainfully applied to resolve a number of important problems that arise in developing suitable planning strategies and management of a mine. Pit optimization starts with the assumption of initial production capacities and the estimates for the related costs and commodity prices. Once the economic parameters are known, the analysis of the ultimate pit limits of the mine is undertaken to determine the portion of the deposit that can be mined economically and safely from geotechnical stability view point. In this research, pit optimization for a heterogeneous iron ore deposit (Deposit-A) has been carried out successfully using Whittle Software. The key aspect investigated was the optimal pit shell across a range of selling prices, as it enables understanding the characteristics of the deposit and potential development strategies considering the areas of greater value. The methodology can be very well utilized when fluctuations in the selling price occur, for predicting the future selling price of the commodity and also strategizing mining plan. For the deposit investigated, it was found that the mine is likely to generate final product of 66.55 MT of Lump Ore (+ 10 mm − 150 mm) and Fines Ore 156.45 MT (− 10 mm) during the life of the mine. The NPV is found to be highly sensitive to the price of Fine ore as quantity of fines in total ore body is around 70%. Except waste, all ore types, no matter how inferior the grade is having (around 10 MT of low grade coming in between Fe @ 45% and Fe @ 25% can be also utilized), are mineable and can be suitably blended to give a product mix of Fe @ 61.68% and more.
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References
C.C Popoff, Computing reserves of mineral deposits: principles and conventional methods. [Washington] U. S. Dept. of the Interior, Bureau of Mines (1966)
W.A. Hustrulid, M. Kuchta, R.K. Martin, Open pit mine planning and design, 3rd edn. (CRC Press, Boca Raton, 2013)
N. Boland, I. Dumitrescu, G. Froyland, A.M. Gleixnerc, LP-based disaggregation approaches to solving the open pit mining production scheduling problem with block processing selectivity. Comput. Oper. Res. 36, 1064–1089 (2007)
K. Dagdelen, E. Topal, M. Kutchta, in Mine Planning and Equipment Selection, ed. by T. Michalakopoulos (Routledge, London, 2000). https://doi.org/10.1201/9780203747124
G.F. Sepúlveda, P.J. Álvarez, J.B. Bedoya, Stochastic optimization in mine planning scheduling. Comput Oper Res 115, 104823 (2020)
L. Martinez, J. McKibben, Understanding real options in mine project valua- tion: a simple perspective. in Fourth International Conference Min. Innov, pp. 23–25 (2010)
B. King, Optimal mining practice in strategic planning. J. Min. Sci. 47(2), 243–247 (2011)
G. Franco, J. Branch, P. Jaramillo, Planeamiento de minas a cielo abierto me- diante optimización estocástica. Bol. Cienc. Tierra 1(31), 107–113 (2012)
R. Dimitrakopoulos (ed.), Stochastic Mine Planning - Methods, Examples and Value in a Uncertain World (Springer International Publishing, 2010). https://doi.org/10.1007/978-3-319-69320-0_9
J. Birge, F. Louveaux, Introtuction to Stochastic Programming, 1st edn. (Springer, New York, 1997)
H. Karimi, N. Duffie, S. Dashkovskiy, Local capacity control for production networks of autonomous work systems with time-varying delays. Proc Eur Control Conf 2009, 2378–2383 (2009)
S. Jamalan, F. Rashidinejad, Compare methods of fix lead, Milawa NPV and Milawa balance algorithm in optimizing the production of open pit mines with whittel software. Open J Geol. (2017). https://doi.org/10.4236/ojg.2017.75041901
U.K. Behera, N.S. Chakravarthi, Performance analysis with data envelopment analysis (DEA). J. Mines Metals Fuels 54(12), 526–529 (2006)
S.K. Sinha, Thesis Entitled Planning Strategies for Enhancing Mine Life vis-à-vis NPV for an Heterogeneous Iron Ore Deposit (Indian Institute of Technology (Indian School of Mines), Dhanbad, 2018)
A. Rimele, R. Dimitrakopoulos, M. Gamache, dynamic stochastic programming approach for open-pit mine planning with geological and commodity price uncertainty. Resour Policy 65, 101570 (2020)
G. Whittle, in Orebody Modelling and Strategic Mine Planning: Uncertainty and Risk Management Modelsed, by R. Dimitrakopoulos (AusIMM Spectrum Series, 2007), pp. 331–336
A.M. Newman, E. Rubio, R. Caro, A. Weintraub, K. Eurek, A review of operations research in mine planning. INFORMS J. 40(3), 222–245 (2010)
M. Osanloo, J. Gholamnejad, B. Karimi, Long-term open pit mine production planning: a review of models and algorithms. Int. J. Min. Reclam. Environ. 22(1), 3–35 (2008). https://doi.org/10.1080/17480930601118947
N. Boland, I. Dumitrescu, G. Froyland, A. Gleixner, LP-based disaggregation approaches to solving the open pit mining production scheduling problem with block processing selectivity. Comput. Oper. Res. 36(4), 1064–1089 (2009)
S. Ramazan, The new fundamental tree algorithm for production scheduling of open pit mines. Eur. J. Oper. Res. 177(2), 1153–1166 (2007)
J. Whittle, A decade of open pit mine planning and optimisation—the craft of turning algorithms into packages. in Proceedings of the 28th International Symposium on Application of Computers and Operations Research in the Mineral Industry (APCOM), pp. 15–24 (1999)
R. Dimitrakopoulos (ed.), Advances in applied strategic mine planning (Springer, Heidelberg, 2018). https://doi.org/10.1007/978-3-319-69320-0
M.E. Gershon, Optimal mine production scheduling evaluation of large scale mathematical programming approaches. Int. J. Min. Eng. 1, 315–329 (1983)
P.A. Dowd, Risk assessment in reserve estimation and open-pit planning. Trans. Inst. Min. Metall. 103, A148–A154 (1994)
M. Godoy, The effective management of geological risk in long-term production scheduling of open pit mines. PhD Thesis, University of Queensland, Qld, Australia (2002)
M. Godoy, R. Dimitrakopoulos, Managing risk and waste mining in long-term production scheduling. SME Trans. 316, 43–50 (2004)
S.A.A. Sabour, R. Dimitrakopoulos, Accounting for joint ore supply, metal price and exchange rate uncertainties in mine design. Adv. Orebody Model Strat. Mine Plann. AusIMM Spectr. Ser. 17, 29–34 (2007)
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Sinha, S.K., Choudhary, B.S. Pit Optimization for Improved NPV and Life of Mine in Heterogeneous Iron Ore Deposit. J. Inst. Eng. India Ser. D 101, 253–264 (2020). https://doi.org/10.1007/s40033-020-00236-z
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DOI: https://doi.org/10.1007/s40033-020-00236-z