Mining
A Preliminary Investigation Into the Geotechnical Interpretation of Geophysical Logs
2004
Compares a full suite of downhole sondes against geotechnical core logging over the 5 m above three coal seams, for geologists and rock engineers assessing roof conditions.
What this report foundGeophysical logging of boreholes above three Witbank seams identified clay rich matrices, stiffness changes, bedding planes and the principal stress direction...
Best Practice Guidelines for the Management of Spontaneous Combustion in Opencast Coal
2024
Guidelines drawn from site testing at opencast coal operations, including trials of gypsum and fly ash sprays applied with a hydro seeder. For pit supervisors and mine safety staff.
What this report foundPractical guidance for opencast operations covers early detection with low cost thermal cameras, prevention, and the treatment methods in current use: water...
Can old bord-and-pillar workings be mapped from surface?
2016
Desktop review updating two earlier assessments, weighing borehole scanning, robots and unmanned aerial platforms as routes to locating old workings ahead of opencast drilling and blasting.
What this report foundNo surface geophysical method can map individual bords and pillars at the depths typical of the Witbank coalfield, a limit the review attributed to physics...
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.
Coal Washability Using Coal Petrography
2019
Summary of postgraduate work validating washability prediction for southern African coals by image analysis and tomography, written for geologists, metallurgists and mining engineers valuing a deposit.
What this report foundA single float sink test destroys the sample and gives one deterministic answer, so it cannot show how washability changes with particle size distribution.
Collation of Historic Thermal Imagery
2008
Pilot exercise pulling scattered thermal survey datasets held by companies and research bodies into one mapping system, with a view to tracking coal fires and mine water discharge.
What this report foundExisting thermal imagery of the Witbank coalfield was traced to its holders and assessed for format, quality, resolution and coverage, then brought into one...
Create Sedimentological and Structural Models to Assist in Identifying Geological Features That Impact on Mining
2001
Regional geology mapped in three dimensions from borehole data supplied by three mining groups, built for mine geologists and planners assessing seam disruption before layout design.
What this report foundA three dimensional model of the northern Witbank and Highveld coalfield was built from more than 1100 borehole logs, with strata sorted into 13 major...
Detection of Old Workings
2008
Review of earlier geophysical work plus literature, setting out method selection and test site requirements ahead of field trials, for engineers assessing undermined ground before development.
What this report foundMicrogravity, resistivity based methods including self potential, and time domain electromagnetics are identified as able to detect and delineate shallow old...
Detection of Old Workings, Sinkholes, Underground Fires and Acid Mine Pollution Using Geophysics and Airborne Thermal Infrared Imagery
2002
Field trials at four collieries comparing ground and airborne geophysical methods, with case studies and an applications guideline for the Witbank and Highveld collieries.
What this report foundMicro-gravity, electrical resistivity and time domain electromagnetics located the boundary between old workings and virgin ground, but no ground technique...
Determine Possible Means to Conduct Large Scale Frictional Ignitions Tests, and the Value of These to Coaltech
2017
A scoping exercise based on technical enquiries to mine safety organisations and discussions at an international conference, aimed at rock engineers and safety practitioners weighing test facility investment.
What this report foundNo operating full scale frictional ignition test facility was found anywhere in the world, and building one was judged expensive, impractical and unlikely to...
Develop Methods to Prevent and Control Spontaneous Combustion Associated With Mining and Subsidence
2003
Fourth year of work at South African collieries, using borehole and infrared temperature monitoring, moisture testing and sealing trials, with control measures for opencast and underground operations.
What this report foundNo standard technique for predicting, controlling or extinguishing spontaneous combustion emerged, and the methods in use proved expensive and not routinely...
Developing a Mechanised Cleaning System – for Cleaning Under and Around Moving Conveyors
2013
Follow on review of mechanised conveyor cleaning equipment close to being usable underground, flameproof and not, written to help the coal industry agree which options to develop.
What this report foundNo flameproof mechanised system for cleaning under and around moving conveyors was found to exist anywhere.