The backfilling research being conducted by the U.S. Bureau of Mines.
Boldt-CMK; Atkins-LA; Jones-FM
Minefill 1993: The 5th International Symposium on Mining with Backfill, June 7-9, 1983, Lulea, South Africa. Glen HW, ed. Johannesburg, South Africa: South African Institute of Mining and Metallurgy (SAIMM), 1993 Jun; :389-395
The U.S. Bureau of Mines is currently investigating the engineering aspects of tailings used as backfill material. Backfilling with mine wastes can reduce surface subsidence through the filling of underground voids, the enhancement of miner health and safety, and the achievement of more efficient and environmentally sound mining methods. The backfill material studied by Bureau researchers includes cemented-paste fill and cemented rock-and-alluvial-sand fill. The work includes the determination of material properties, the transportation and placing of backfill, instruments to monitor the backfill, and computer modelling. This paper presents laboratory data about the effects of particle-size gradation on the unconfined compressive strength of tailings backfill. Fine tailings (100 per cent minus 0,074 mm) were added to varying amounts of coarse silica sand to alter the fineness modulus. It was found that the unconfined compressive strength increased for the mixes containing finer tailings and sand when the water/cement ratios and slumps were held constant. Another test series showed that the temperatures of cold material decreased the unconfined compressive strength of the mix. An overview is given of the Bureau's 'Mining With Backfill' research programme, which studies the effective use of backfill material. Continuing research includes investigations of the strength of backfill containing total-gradation tailings, the development of a paste-pump simulator, the field instrumentation of backfill and pillars, and the computer modelling of backfill stability.
Mining; Mining industry; Underground mines; Underground mining; Computer models
C.M.K. Boldt, U.S. Bureau of Mines, Spokane, U.S.A.
Minefill 1993: The 5th International Symposium on Mining with Backfill, June 7-9, 1983, Lulea, South Africa