Control of dilution using the modified creeping cone method at Selebi North Mine

Mining companies are adopting bulk mining methods in their operations because they are safe and can be easily mechanized and automated. The introduction of the creeping cone method at Selebi North Mine in Botswana reduced ore dilution by a half. However, the low grades of the mineable reserves in the deeper sections of the mine require further reductions in dilution to mine profitably. The modified creeping cone (MCC) method was designed to create stable stope wall conditions and give lower dilution levels. Voussoir arch and simple beam theory methods were used to design the MCC method. The results show that for stopes 50 m high and 4-22 m wide, 50-185 m of room span can be mined using cable bolt reinforced walls. With the MCC method, ore dilution can be reduced to 19.2% while ore grades will increase by 10.5%.