Selection of cut off grade in long-term open pit mine planning is a tough research challenge now-a-days. The subsequent operational planning for the selected cut off grade decides the economic factor in mine production
scheduling. The distribution of grade, sequence of mining operation, economic parameters, the capacities of mining operations are influencing points for deciding the model. In any given period of time the dynamic cut off grade is a
function of the availability of ore and the capacity of stockpile as well as the process plant. The extraction sequence and cut off grade strategy should be considered simultaneously in order to achieve the optimum result. By keeping these points in first row, various attempts have been made to develop an electronic technique for the extraction sequence of open pit mines. Because of the numerous variables involved for getting the optimum result, different approaches have been made is not sufficient to widespread acceptance. A new model has therefore been proposed to overcome this shortcoming. The optimum sequences of extraction in each period are recognized by optimum processing decisions. To examine the applicability of the model developed, a case study is offered to validate.
Keywords: NPV, production scheduling, economic loss, mining sequence, cut off grade
1. Akaike, A., and Dagdelen, K. (1999): A strategic production scheduling method for an open pit mine. Proceedings of the
28th Application of Computers and Operation Research in the Mineral Industry, 729-738.
2. Asad, M. W. A. (2002): Development of generalized cutoff grade optimization algorithm for open pit mining
operations. Journal of Engineering and Applied Sciences, 21(2).
3. Ataei, M., and Osanloo, M. (2003): Methods for calculation of optimal cutoff grades in complex ore deposits. Journal of
Mining Science, 39(5), 499-507.
4. Ataei, M., and Osanloo, M. (2004): Using a combination of genetic algorithm and the grid search method to determine
optimum cutoff grades of multiple metal deposits. International Journal of Surface Mining, Reclamation and Environment,
5. Boland, N., Dumitrescu, I., Froyland, G., and Gleixner, A. M. (2009): LP-based disaggregation approaches to solving the open
pit mining production scheduling problem with block processing selectivity. Computers & Operations Research, 36(4), 1064-
1089.6. Cairns, R. D., and Shinkuma, T. (2003): The choice of the cutoff grade in mining. Resources Policy, 29(3-4), 75-81.
7. Dagdelen, K. (1985): Optimum multi-period open pit mine production scheduling. PhD thesis, Colorado School of
Mines, Golden, Colorado.
8. Dagdelen, K. (1986): Optimum open pit mine production scheduling by Lagrangian parameterization. Proc. of the 19
9. Dagdelen, K. (1993): An optimization algorithm for open pit mine design. In 24th International Symposium on the Application
of Computers and Operations Research in the Mineral Industry (APCOM) (pp. 157-165). 10. Dagdelen, K. (1993): An NPV
optimization algorithm for open pit mine design. In Proceedings of the 24th International Symposium on Application of
Computers and Operations Research in Minerals Industries (pp. 257-263).
11. Gershon, M. E. (1983): Optimal mine production scheduling: evaluation of large-scale mathematical
programming approaches. International Journal of Mining Engineering, 1(4), 315-329.
12. Gholamnejad, J. (2009): Incorporation of rehabilitation cost into the optimum cut-off grade determination. Journal of the
Southern African Institute of Mining and Metallurgy, 109(2), 89-94.
13. Gleixner, A. M. (2009): Solving large-scale open pit mining production scheduling problems by integer programming.
14. Halls, J. L., Bellum, D. P., and Lewis, C. K. (1969): Determination of optimum ore reserves and plant size by incremental
financial analysis. Transactions of the Institute of Mining and Metallurgy, 78, A20-A26.
15. Johnson, T. B. (1968): Optimum open pit mine production scheduling (No. ORC-68-11). California Univ Berkeley Operations
16. Johnson, T. B. (1969): Improving returns from mine products through use of operations research techniques (Vol. 7230). US
Dept. of the Interior, Bureau of Mines.
17. Kawahata, K. (2006): New algorithm to solve large scale mine production scheduling problems by using the Lagrangian
relaxation method, A (Doctoral dissertation, Colorado School of Mines. Arthur Lakes Library).
18. Lane, K. F. (1964): Choosing the optimum cut-off grade. Q. Colorado Sch. Min., 59, pp-811.
19. Lane, K. F. (1988): The economic definition of ore: cut-off grades in theory and practice (pp. 149). London: Mining Journal
20. Mogi, G., Adachi, T., Akaike, A., and Yamatomi, J. (2001): Optimum Production Scale and Scheduling of Open Pit Mines Using
Revised 4-D Network Relaxation Method. Journal-mining and materials processing institute of Japan, 117(7), 599-603.