Published in June 2008 Australian Longwall Magazine
Currently there is no real-time atmospheric Diesel Particulate Matter (DPM) monitor working in Australia’s underground coal mines. In response to the need for such a monitor, an Australian Coal Association Research Program study was undertaken by Gillies Wu Mining Technology, which set about to develop, test and prove up a DPM real-time atmospheric monitoring unit (termed the D-PDM) under mine conditions.
The project’s main activities were through internationally recognised laboratory testing to evaluate a new design and comprehensively test the unit underground. A series of tests in five mines were carried out to establish the robustness and reliability of the new approach.
Gillies said the project had achieved all its aims.
“Tests have been undertaken at points of expected high atmospheric DPM. The monitors have performed extremely well within the underground mine environment in evaluating DPM during the various phases of the production cycle,” he said.
“They have also closely examined the influence of aspects of the mine ventilation system. The monitor has successfully reported data when used as a static or stationary instrument and when placed within the cab of a moving vehicle.”
Gillies said the outcomes of the project provided the industry access to an enhanced tool for understanding the presence of DPM in the mine atmosphere.
Throughout the D-PDM mine testing phase SKC monitor comparison tests were undertaken. The SKC system results were analysed for carbon and gave EC and TC readings from DPM samples.
Analyses from all mines’ test series compared with SKC impactor collection determinations for EC and TC showed close correlations.
“These results gathered over many testing circumstances, mines and mine situations demonstrate the validity of the D-PDM monitor as a very significant contribution to the accurate understanding of DPM levels in mines,” Gillies said.
He added that an important point was that the results demonstrated calibration relationships vary from mine to mine. “This is to be expected and is due to differences in aspects such as mine atmospheric contamination, vehicle fleet variations, fuel type, engine maintenance and engine behaviour.
“The project has extended some recommendations on the need for greater understanding of the complexities of DPM in the mine atmosphere. The project proved up the concept of a real-time DPM monitoring instrument and provides an alternative to the SKC shift average monitoring system.”
The project examined the advantages and disadvantages of in-mine use of the new device compared to the SKC unit. “The D-PDM unit gives real-time evaluations and so is very powerful in allowing understanding of DPM emission patterns in the fast-changing mine production cycle and in undertaking engineering evaluation exercises.”
Gillies said already the success of the project had caused a number of mines to reconsider their approach to handling the issue of DPM in the underground environment.
“The new approach to monitoring allows high sources of DPM to be identified through underground measurement and action taken to reduce concentration levels that miners are exposed to.”
