Document Type : Original Research Paper

Authors

Dept. of Mining Engineering, Tarbiat Modarres University, Tehran, Iran

Abstract

Reserve evaluation is one of the most important parameters for mine designing and several methods have been developed in this regards. Among these methods, in addition to geostatistical methods, artificial methods such as Artificial Neural Networks (ANN) are suitable for reserve evaluation. In this research, geometrical and block model of ٍEsfordi phosphate mine are prepared and the reserve is estimated. The block model contains 100 thousand blocks with dimensions of 25×25×5 m. To estimate the grade of each block,both methods of geostatistical and ANN methods are used. For geostatistical estimation, normal kriging is applied. In ANN a perceptron multilayer network is used and for training of network LM method is considered. Based on geostatistical and ANN methods, the amount of estimated reserve is 16.5 Mt with an average grade of 11.44% and 17.5 Mt with an average grade of 11.83%, respectively, considering a cut-off grade of 6%. The results obtained from these two methods are identical to each other and difference is less than 6%. This estimation is a requisite for improving present design of the mine with an objective of selective mining up to sea level of +1720.
 

Keywords

References
Coombes, J., 2002- Handy hints for variography, Snowden Associates Ltd.
David, M., 1982- Geostatistical ore reserve estimation, Elsevier Scientific Publishing Co.
Katsuaki Koike et al., 2001-Neural network-Based estimation of principal metal contents in the Hokuroku District, Northern Japan , Natural Resources Research, Vol. 11, No. 2.
Matias, J. M. et al., 2004-Comparison of Kriging and Neural networks with application to the exploitation of a Slate mine, Mathematical Geology, Vol. 36, No. 4.
Samanta, B. et al., 2005- An application of Neural networks to gold grade estimation in Nome Placer Deposit,”Journal of South African Inst. Mine, Metal, Vol. 105, pp. 237-246.