On-line version ISSN 2411-9717
J. S. Afr. Inst. Min. Metall. vol.108 n.12 Johannesburg Dec. 2008
Limestone quarry quality optimization for a cement factory in Turkey
A.H. Onur; G. Konak; D. Karakuş
Dokuz Eylul University, Faculty of Engineering, Mining Engineering Department, Turkey
Many factors govern the size and shape of an open pit, and these must be properly understood and used in the short and long-term planning of any open pit and quarrying operation. The importance of each factor will depend on the particular project, but the geology, grade, and localization of mineralization, extent of the deposit, topography, property boundaries, production rates, bench height, pit slopes, road grades, mining costs, and cut-off grades are key elements of open pits. This paper discusses the work done on the above parameters in order to provide an optimal production plan for a limestone quarry and clay deposits that provide raw material for a cement factory in Turkey.
Soke cement factory has 1 400 000 tons of clinker capacity and is located on the western part of Turkey, in the province of Aydın. It is one of the largest facilities in the cement sector in terms of capacity, and it has a large advantage over facilities because the location of the factory was chosen to obtain the raw materials necessary for cement production within very short distances. However, the old reserves that supplied limestone to the factory had been reported to have run out, and therefore new limestone reserves in the same province have been investigated over the years by experienced geologists. From surface samples, high MgO content was reported in the neighbourhood of limestone formations with high dolomatization; hence, other alternatives were taken into consideration. One alternative with better chemical composition had been found 24 km away from the factory, but the haulage cost of limestone was unacceptable for the factory due to high diesel prices in Turkey.
The maximum allowable MgO content in the pre-mix feed to a rotating furnace is 2.5% MgO content in pre-mix from both limestone and clay deposits. The clay deposits belonging to the cement factory have higher MgO content than the limestone deposit, and therefore this quality problem was taken into consideration first, instead of transporting material from 24 km away.
This study gives the details of work done to evaluate both the clay and limestone deposits, statistical analysis performed on core samples taken from drill holes, mathematical modelling for both sites, and most importantly of all, in-pit homogenization work that reduced the pre-mix MgO content. As a result of this study, the profitable limestone quantity has been improved in order to serve the cement factory over a projected 25 additional years without using any material from the close deposit.
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1. CACCETTA, L., KELSEY, P. and GIANNINI, L.M. Open Pit Mine Production Scheduling, A.J. Basu, N. Stockton and D. Spottiswood (eds.), Computer Applications in the Minerals Industries International Symposium (3rd Regional APCOM), Austral. Inst. Min. Metall. Publication Series 5. 1998. pp. 65-72. [ Links ]
2. CACCETTA, L., GIANNINI, L.M. and KELSEY, P. Application of Optimization Techniques in Open Pit Mining, Proceedings of the Fourth International Conference on Optimization Techniques and Applications (ICOTA'98) (L. Caccetta et al. Editors.), vol. 1, 1998. pp. 414-422. [ Links ]
3. CACCETTA, L. and HILL, S.H. An Application of Branch and Cut to Open Pit Mine Scheduling. Journal of Global Optimization, Kluwer Academic Publishers, Netherlands, vol. 27, 2003. pp. 349-365, [ Links ]
4. DAGDELEN, K. and JOHNSON, T.B. Optimum Open Pit Mine Production Scheduling by Lagrangian Parameterization, Proc. 19th APCOM Symposium of the Society of Mining Engineers (AIME) 1986. pp. 127-142. [ Links ]
5. DENBY, B. and SCHOFIELD, D. The Use of Genetic Algorithms in Underground Mine Scheduling, Proc. 25th APCOM Symposium of the Society of Mining Engineers (AIME, New York), 1995. pp. 389-394. [ Links ]
6. DENBY, B., SCHOFIELD, D. and BRADFORD, S. Neural Network Applications in Mining Engineering, Department of Mineral Resources Engineering Magazine, University of Nottingham, 1991, pp.13-23. [ Links ]
7. FRANCOIS-BONGARCON, D.M. and GUIBAL, D. Parametization of Optimal Designs of an Open Pit Beginning of a New Phase of Research, Trans. SME, AIME 274, 1984. pp. 1801-1805. [ Links ]
8. GERSHON, M. Mine Scheduling Optimization with Mixed Integer Programming, Mining Engineering, vol. 35, 1983. pp. 351-354. [ Links ]
9. GERSHON, M. Heuristic Approaches for Mine Planning and Production Scheduling, Int. Journal of Mining and Geological Engineering, vol. 5. 1987, pp. 1-13. [ Links ]
10. KIM, Y.C. Open-Pit Limits Analysis: Technical Overview, A. Weiss (ed.), Computer Methods for the 80's, AIME, New York, 1979. pp. 297-303. [ Links ]
11. LERCHS, H. and GROSSMANN, I.F. Optimum Design of Open Pit Mines, Canad. Inst. Mining Bull. vol. 58. 1965, pp. 47-54. [ Links ]
12. MATHERON, G. Le Parametrage des Contours Optimaux, Technical Report No. 403, Centre de Geostatistiques, Fontainebleau, 1975. France. [ Links ]
13. MATHERON, G. Le Parametrage Technique des Reseues, Technical Report No. 453, Centre de Geostatistiques, Fontainebleau, 1975. France. [ Links ]
14. PICARD, J.C. Maximum Closure of a Graph and Applications to Combinatorial Problems, Management Sc. vol. 22, 1976. pp. 1268 -1272. [ Links ]
15. TOLWINSKI, B. and UNDERWOOD, R. A Scheduling Algorithm for Open Pit Mines, IMA Journal of Mathematics Applied in Business and Industry, vol. 7, 1996. pp. 247-270. [ Links ]
16. WHITTLE, J. Open Pit Optimization, Surface Mining (2nd Edition), AMIE., 1990. pp. 470- 475. [ Links ]