Coal – Related Regenerative Innovation for Concrete and Segmental Block Pavements

Conventional cost accounting at the mines studied could not report on physical structure or materials flow, so environmental costs such as water, energy and consumables stayed hidden and chances to cut them were lost. Four case studies across different commodities and mining methods showed the same limitations. An environmental management accounting model is proposed to identify and allocate those costs.

Existing thermal imagery of the Witbank coalfield was traced to its holders and assessed for format, quality, resolution and coverage, then brought into one geographic information system with supporting metadata. Satellite thermal bands give a regional picture only; detailed mapping of coal fires or acid drainage discharge needs high resolution aerial surveys.

A stand-alone device was built that detects micro-seismicity within 100 m of the roof and raises an alarm when preset thresholds are exceeded, giving early warning of goafing. Input parameters proved not to vary with geotechnical setting. Man-made noise triggering false alarms remained the main obstacle, addressed by signal conditioning and sensor placement.

Gas sampling on coal mine dumps found rehabilitation very effective at cutting emissions. Even incomplete rehabilitation held carbon dioxide below about 1 kg per square metre a year, against over 100 on unrehabilitated ground and as much as 7 000 where combustion was active, though burning areas were small. Sulphur oxides, nitrogen oxides, ammonia and methane were low.