An assessment of dilution in sublevel caving at Kazansi Mine

Dilution, which is difficult to quantify accurately, is a major concern in underground mining. The level of dilution in the sublevel caving areas at Kazansi Mine is currently difficult to assess owing to the lack of data. The acceptable dilution levels differ from mine to mine but the current planned dilution of 35% on the mine is too high. This paper attempts to assess the dilution levels in sublevel caving areas (Blocks 5 and 6) at Kazansi Mine. The excess tonnage concept when used to compute the dilution factor for the blocks gave a dilution factor of 44.45% while the lowering grade concept gave a factor of 17.91%. The overall dilution factor for the block was found to be 31.18%. The lowering grade concept of dilution factor computation is recommended as it gives smaller value of 17.91%.