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gas drainage/outbursts |
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overview |
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GAS DRAINAGE/OUTBURSTS
Overview
The Ventilation part of the basic mining process/terminology section made mention of gas drainage, with a brief description of the way in which outbursts occur (where some change in seam conditions interferes with the usual gradual release of gas into the workings). Early gas drainage work in Australian mines was aimed at removing gas prior to mining (particularly secondary extraction) solely in order to reduce the demands on ventilation for gas dilution purposes. In fact in some cases gas drainage holes were intentionally stopped short of future roadway locations to avoid problems when the holes were intersected during development.
At that time, outbursts were frequently not recognized for what they actually were at some mines, and terms such as "pressure bumps" or "slumps" were often applied to what were actually small outbursts. At other mines the true nature of the problem was recognized earlier and pioneering work related to removal of gas and devising methods of identifying when locations were safe to work were being developed. Such work gradually increased as the more widespread nature of the risk became apparent, sometimes through tragic incidents involving fatalities.
It is always risky to mention individuals involved in such work for fear of offending other deserving individuals by their omission, but in this instance work carried out by Allan Hargreaves, Ripu Lama and Ray Williams deserves particular recognition.