ORIGINAL PAPER
Optimization of the cut-off grade for underground polymetallic mines
1
School of Civil and Resource Engineering, University of Science & Technology Beijing
2
SHANDONG GOLD GROUP CO.,LTD, Jinan 250100, China
Submission date: 2018-08-23
Final revision date: 2018-10-24
Acceptance date: 2019-01-24
Publication date: 2018-03-31
Corresponding author
Gospodarka Surowcami Mineralnymi – Mineral Resources Management 2019;35(1):25-42
KEYWORDS
TOPICS
Optimization of resources and reserves managementRational and efficient development and utilization of mineral resourcesEconomics of mineral industries
ABSTRACT
One of the most critical aspects of mine design is to determine the optimum cut-off grade. Despite Lane’s theory, which aims to optimize the cut-off grade by maximizing the net present value (NPV), which is now an accepted principle used in open pit planning studies, it is less developed and applied in optimizing the cut-off grade for underground polymetallic mines than open pit mines, as optimization in underground polymetallic mines is more difficult. Since there is a similar potential for optimization between open pit mines and underground mines, this paper extends the utilization of Lane’s theory and proposes an optimization model of the cut-off grade applied to combined mining-mineral processing in underground mines with multi-metals. With the help of 3D visualization model of deposits and using the equivalent factors, the objective function is expressed as one variable function of the cut-off grade. Then, the curves of increment in present value versus the cut-off grade concerning different constraints of production capacities are constructed respectively, and the reasonable cut-off grade corresponding to each constraint is calculated by using the golden section search method. The defined criterion for the global optimization of the cut-off grade is determined by maximizing the overall marginal economics. An underground polymetallic copper deposit in Tibet is taken as an example to validate the proposed model in the case study. The results show that the overall optimum equivalent cut-off grade, 0.28%, improves NPV by RMB 170.2 million in comparison with the cut-off grade policy currently used. Thus, the application of the optimization model is conducive to achieving more satisfactory economic benefits under the premise of the rational utilization of mineral resources.
METADATA IN OTHER LANGUAGES:
Polish
Optymalizacja wartości granicznej surowca dla podziemnych kopalń rud polimetalicznych
ocena graniczna, krańcowa ekonomia, optymalizacja, podziemne kopalnie polimetaliczne
Jednym z najbardziej istotnych aspektów projektowania kopalni jest określenie optymalnej wartości granicznej surowca. Pomimo teorii Lane’a, mającej na celu optymalizację wartości granicznej surowca poprzez maksymalizację wartości bieżącej netto (NPV), obecnie stosowanej w studiach planowania górnictwa odkrywkowego, natomiast jest ona mniej rozwinięta i stosowana w optymalizowaniu wartości granicznej surowca dla podziemnych kopalń rud polimetalicznych ze względu na znaczne trudności. W artykule rozszerzono wykorzystanie teorii Lane’a poprzez propozycję modelu optymalizacji wartości granicznej surowca, zastosowanego do połączonych procesów górniczo-przeróbczych podziemnych kopalń rud polimetalicznych. Za pomocą modelu wizualizacji 3D zasobów i wykorzystaniu ekwiwalentnych współczynników określono funkcję celu wyrażoną jako jedną zmienną funkcję oceny wartości granicznej. Następnie konstruowane są krzywe przyrostu wartości aktualnej w stosunku do wartości granicznej dotyczące różnych ograniczeń zdolności produkcyjnych, a rozsądna wartość graniczna odpowiadająca każdemu ograniczeniu jest obliczana za pomocą metody wyszukiwania złotego odcinka. Zdefiniowane kryterium globalnej optymalizacji oceny granicznej określa się poprzez maksymalizację efektów ekonomicznych. Jako przykład do sprawdzenia proponowanego modelu w studium przypadku wykorzystano podziemne złoża polimetaliczne miedzi w Tybecie. Wyniki pokazują, że całkowita optymalna ekwiwalentna wartość graniczna, 0,28%, poprawia NPV o 170,2 milionów juanów w porównaniu z obecnie stosowaną oceną graniczną. Tak
więc zastosowanie modelu optymalizacyjnego sprzyja osiągnięciu bardziej satysfakcjonujących korzyści ekonomicznych przy założeniu racjonalnego wykorzystania zasobów mineralnych.
REFERENCES (24)
1.
Ahmadi, M.R. 2018. Cutoff grade optimization based on maximizing net present value using a computer model. Journal of Sustainable Mining 17(2), pp. 68–75.
2.
Ahmadi, M.R. and Shahabi, R.S. 2018. Cutoff grade optimization in open pit mines using genetic algorithm. Resources Policy 55, pp. 184–191.
3.
Asad, M. 2005. Cutoff grade optimization algorithm with stockpiling option for open pit mining operations of two economic minerals. International Journal of Surface Mining, Reclamation and Environment 19, pp. 176–187.
4.
Asad, M. 2007. Optimum cut-off grade policy for open pit mining operations through net present value algorithm considering metal price and cost escalation. Engineering Computations 24, pp. 723–736.
5.
Asad, M. and Topal, E. 2011. Net present value maximization model for optimum cut-off grade policy of open pit mining operations. Journal of the Southern African Institute of Mining and Metallurgy 111, pp. 741–750.
6.
Asad et al. 2016 – Asad, M.W.A., Qureshi, M.A. and Jang, H. 2016. A review of cut-off grade policy models for open pit mining operations. Resources Policy 49, pp. 142–152.
7.
Ataei, M. and Osanloo, M. 2003. Methods for calculation of optimal cutoff grades in complex ore deposits. Journal of Mining Science 39, pp. 499–507.
8.
Cetin, E. and Dowd, P. 2016. Multiple cut-off grade optimization by genetic algorithms and comparison with grid search method and dynamic programming. Journal of the Southern African Institute of Mining and Metallurgy 116(7), pp. 681–688.
9.
Gu et al. 2010 – Gu, X.-W., Wang, Q., Chu, D.-Z. and Zhang, B. 2010. Dynamic optimization of cutoff grade in underground metal mining. Journal of Central South University of Technology 17, pp. 492–497.
10.
Hall, B. and Stewart, C. 2004. Optimising the strategic mine plan-methodologies, findings, successes and failures [In:] Proceedings Orebody Modelling and Strategic Mine Planning, pp. 49–58.
11.
Jia, W. and Chen, J.-B. 2008. Discussion on regulation model of marginal grade and its application. Natural Resource Economics of China 6, pp. 35–37.
12.
Lane, KF. 1964. Choosing the optimum cut-off grade. Colorado School of Mines Quarterly 59, pp. 485–492.
13.
Lane, KF. 1984. Cut-off grades for two minerals [In:] Proceedings of the 18th APCOM, London, England, pp. 485–492.
14.
Lane, KF. 1988. The economic definition of ore: cut-off grades in theory and practice. Mining Journal Books, London, England.
15.
Osanloo, M. and Ataei, M. 2003. Using equivalent grade factors to find the optimum cut-off grades of multiple metal deposits. Minerals Engineering 16, pp. 771–776.
16.
Osanloo et al. 2008 – Osanloo, M., Rashidinejad, F. and Rezai, B. 2008. Incorporating environmental issues into optimum cut-off grades modeling at porphyry copper deposits. Resources Policy 33, pp. 222–229.
17.
Poniewierski et al. 2003 – Poniewierski, J., MacSporran, G. and Sheppard, I. 2003. Optimisation of cut-off grade at Mount Isa Mines Limited’s enterprise mine [In:] Proc 12th Internat Sympos Mine Planning and Equipment Selection, Australasian Institute of Mining and Metallurgy, Carlton South, Australia, pp. 531–538.
18.
Sun et al. 2013 – Sun, C.-K., Dai, X.-J. and Chen, J. 2013. The application of theory of equivalent grade in a polymetallic deposit. Henan Science 31, pp. 1481–1484.
19.
Taylor, H. 1972. General background theory of cut-off grades. Transactions of the Institute of Mining and Metallurgy 96, pp. A204–A216.
20.
Wang et al. 2007 – Wang, Z.-J., Wang, Y.-C., Jiang, W.-M., Hu, S.-L. and Liu, J.-P. 2007. Analysis and application of cutoff grade in gold ore extraction. Gold Science and Technology 15, pp. 54–57.
21.
Whittle, J. and Wharton, C. 1995a. Optimising cut-off grades. Mining Magazine 173, pp. 287–289.
22.
Whittle, J. and Wharton, C. 1995b. Optimizing cut-offs over time [In:] Proceedings of the 25th APCOM, Brisbane, Australia, pp. 261–265.
23.
Yasrebi et al. 2015 – Yasrebi, A.B., Wetherelt, A., Foster, P., Kennedy, G., Ahangaran, D.K., Afzal, P. and Asadi, A. 2015. Determination of optimised cut-off grade utilising non-linear programming. Arabian Journal of Geosciences 8(10), pp. 8963–8967.
24.
Zarshenas, Y. and Saeedi, G. 2017. Determination of optimum cutoff grade with considering dilution. Arabian Journal of Geosciences 10(7), p. 165.
Share
RELATED ARTICLE
| eISSN: | 2299-2324 |
| ISSN: | 0860-0953 |
We process personal data collected when visiting the website. The function of obtaining information about users and their behavior is carried out by voluntarily entered information in forms and saving cookies in end devices. Data, including cookies, are used to provide services, improve the user experience and to analyze the traffic in accordance with the Privacy policy. Data are also collected and processed by Google Analytics tool (more).
You can change cookies settings in your browser. Restricted use of cookies in the browser configuration may affect some functionalities of the website.
You can change cookies settings in your browser. Restricted use of cookies in the browser configuration may affect some functionalities of the website.
