Block cave dewatering: A case history from Finsch diamond mine, Northern Cape (2007)

Beaton, R., Preece, C.A., Morton, K.L., Twiggs, C.A. & Wilson, A.D.

Abstract
Finsch Diamond Mine was opened in 1966, the pipe at surface was elliptical with an  area of 17.9ha, and is known to extend beyond 1200m below surface. Mining by means  of open pit, until a final economical depth of 423m was reached in 1990. Blasthole  open stopping was adopted until 2004 when Block 4, the first planned block cave, came  into production. Finsch Geology includes dolomite below 29 level (290m depth).  Groundwater flows through major structures. The early installation of ring tunnels from  1979 to 1984 advance dewatered the mine by passive drainage to about 630m depth.  Below 630m active dewatering has been achieved by the installing of 7 pumping  boreholes. A piezometer network shows that the active dewatering is able to maintain a  piezometer level below the 65 level and therefore 20m below the block cave.

Beaton, R., Preece, C.A., Morton, K.L., Twiggs, C.A. & Wilson, A.D. (2007) ‘Block cave dewatering: A case history from Finsch diamond mine, Northern Cape’, 1st International Symposium on Block and Sublevel Caving, Cape Town, SAIMM, pp. 239–264.