Anglo shares early findings on lead-up to mine blast

Anglo American has revealed findings from expert analysis into the events leading up to a blast that seriously injured five men at Grosvenor mine near Moranbah. But the internal investigation to date has failed to pinpoint what triggered the methane ignition that occurred on May 6. “We know from our expert analysis that there was a significant and unusual overpressure event on 6 May, where a large amount of methane was released into the longwall area, and seconds later a brief ignition occurred," Anglo American Metallurgical Coal CEO Tyler Mitchelson said. "At this stage, the ignition source has not been conclusively determined and testing continues. “We also know that in the hours leading up to the incident, there were no non-compliant methane readings in the longwall area." Mr Mitchelson said the company’s focus continued to be on providing ongoing support for their five injured colleagues, four of whom have now been released from hospital, while the fifth colleague remains in a stable condition. Mr Mitchelson said while investigations were progressing and may take some time to formally conclude, the safety of his workforce was the priority and the company would continue to review controls in place across its underground mines as any technical or other findings become available from the investigations. “Since 2016, we have invested around $230 million on gas drainage and gas management activities at Grosvenor mine," he said. "Despite this investment and extensive controls in place to prevent an underground ignition of methane, we need to further improve our controls to respond to the specific combination of factors of an unusual and large overpressure event in the vicinity of the longwall with a potential ignition source. “By drawing on technical learnings and information as it becomes available from the investigations, we have begun a review of our site methane management controls, which includes assessing additional technology options and applying any further improvements across our underground mines. “As a first step, we are beginning a pilot study at our Moranbah North mine to assess the use of pressure sensors to remove power from the longwall face as an additional control if a significant overpressure event occurs. "Whilst pressure sensors are already in use today, across the industry they have not been integrated for this particular purpose. Learnings from the pilot will be incorporated across our underground mines and shared with industry. “We have already invested considerably in progressing the automation of our longwall equipment and expediting this work will also be part of the solution to reducing risks in underground mining.” Mining activities remain suspended at Grosvenor and Mr Mitchelson said the workforce had continued to be supported on full pay since the incident as the company worked through its future plans step by step. He said the serious injury of five workers was unacceptable and that the company would ensure that all relevant learnings from investigations underway and the Board of Inquiry were incorporated across the business. Inquiry proceedings to be live-streamed A Queensland mine safety board of inquiry is underway into multiple cases of excess methane gas levels at Bowen Basin mines within the past year, following the underground gas explosion at the Grosvenor longwall. They include 27 high potential incidents at Grosvenor involving exceedence of methane (more than 2.5 per cent) in and around the longwall between July 1 last year and May 5, 11 such high potential incidents at Grasstree mine, one at Moranbah North and one at Oaky North in the same timeframe. The Queensland Coal Mining Board of Inquiry will commence public hearings from August 4 at the Brisbane Magistrates Court. Chairperson Terry Martin SC said the first tranche of public hearings would not concern the serious accident at Grosvenor mine on May 6 or methane exceedances at that mine. "Investigations into all of these matters continue but more needs to be done before witnesses are called at public hearings," he said. “These public hearings in August will concern the role of the Inspectorate, the role of the industry and site safety and health representatives, how the management structure and employment arrangements of the mining companies may impact on mine safety, as well as the methane exceedances at Grasstree, Moranbah North and Oaky North mines.” A live stream broadcast of proceedings will be available on the Inquiry’s website and accessible from any internet enabled device. “We understand the importance of this inquiry to regional Queensland mining communities and we are investigating additional viewing facilities in regional locations,” Mr Martin said. Information for the inquiry can be provided to the Executive Director at the Queensland Coal Mining Board of Inquiry by tomorrow (July 17) at info@coalminesinquiry.qld.gov.au

Anglo shares early findings on lead-up to mine blast

Industry Queensland

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