Verification of the New Coal Pillar Strength Formula and Investigations Into the Prediction of Pillar Life in Witbank and Highveld Coalfields
Covers pillar load and strength estimation, the limits of tributary area theory, and the extraction gains available from revised strength formulae, for rock engineers designing bord and pillar workings.
by I Canbulat | February 2004
Laboratory testing showed coal specimen strength rising linearly with width to height ratio and falling exponentially with specimen size, the size effect becoming insignificant beyond about 2 m diameter. The slope of that relationship was the same for coals from different mines, while the intercept varied with specimen size.
R1500,00
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Cleaning Near Moving Conveyors
2011
First phase of a two part investigation into conveyor cleaning practice at South African coal mines, covering the legal position, current mine practice and available machinery.
What this report foundConveyance legislation promulgated in 2008 and enforced soon after left the coal industry without a lawful way to clean near and under running conveyors.
R1500,00
Conveyance legislation promulgated in 2008 and enforced soon after left the coal industry without a lawful way to clean near and under running conveyors. The first phase defined the problem, recorded the cleaning practices mines already use successfully, and built a structured database of mechanised platform options worth pursuing. High risk areas remain drives, take ups, snub and tail pulleys and transfer points.
Characterization of Spontaneous Combustion Emissions
2005
Aircraft and ground monitoring at a working colliery in summer and winter, measuring trace gases and particulates from spontaneous combustion, for air quality management and mine planning.
What this report foundAircraft and ground based measurements at Kleinkopje Colliery showed spontaneous combustion to be a significant source of fine particles, with PM2.5...
R1500,00
Aircraft and ground based measurements at Kleinkopje Colliery showed spontaneous combustion to be a significant source of fine particles, with PM2.5 concentrations 91 per cent higher inside a combustion plume than outside it. Sulphur dioxide, nitrogen dioxide and carbon dioxide were also raised in plume, and benzene and toluene were detected. Average particle size was below one micron.
Evaluate the Remaining Resources of Low Phosphorus Coal in Mpumalanga Province
2004
Assessment of remaining metallurgical grade coal in the Witbank, Highveld and Ermelo coalfields from national borehole records, for resource planners and buyers of reductant coal.
What this report foundTonnage estimates for the remaining low phosphorus resource could not be produced, because the phosphorus analyses supplied by mining companies did not state...
R1500,00
Tonnage estimates for the remaining low phosphorus resource could not be produced, because the phosphorus analyses supplied by mining companies did not state what had been measured. Distribution trends were still mapped. Coal at or below 0.010 per cent phosphorus is widespread in the Witbank Coalfield, restricted to the far northwestern Highveld, and follows a northwest to southeast band in eastern Ermelo.
Coal Mine Acid Mine Drainage Treatment and Sludge Processing
2010
Laboratory evaluation of acid drainage treatment paired with thermal recovery of reagents from the resulting sludge, with capital and operating cost estimates for mine water planners.
What this report foundA modified alkaline barium calcium process was tested on coal mine acid drainage, using calcium hydroxide neutralisation, hydrogen sulphide metal removal and...
R1500,00
A modified alkaline barium calcium process was tested on coal mine acid drainage, using calcium hydroxide neutralisation, hydrogen sulphide metal removal and barium carbonate sulphate removal. Gypsum formation during water treatment fell by 80 per cent, cutting the sludge sent to costly downstream processing to a fifth. Temperature, reaction time, reagent ratios and feed particle size affected thermal treatment of the sludge.