Mark Gleadhill – Manager, Cool Mine Pty Ltd
37 videos found
Ravindu Goonawardene
Geology and Geotechnical Superintendent, Anglo American – Grosvenor Mine
Chris Crosby
Surveying Superintendent, Anglo American – Grosvenor Mine
The risk of fatalities due to roof and rib failures is still prevalent in underground coal mines which highlights the fundamental importance of monitoring roof and ribs in underground roadways. Monitoring strata deformation and convergence in underground roadways is a key metric for measuring instability of excavations. Visual inspections, telltales, extensometers and instrumented bolts are some of the methods used to quantify strata deformation.
The significant limitations of the current methods only provide a point-measurement along the roadway. Using laser technology allows the mine to scan and measure large regions of roof and ribs across continuous regions with millimetre accuracy.
The Maptek SR3 laser scanner has been used as a control during the rib optimisation trial at Grosvenor. This technology provides a baseline scan and subsequent scans to ascertain the extent of deformation throughout the active development mining areas. Thus, allowing geotechnical engineers to assess the adequacy of the trialled support system. Moreover, this technology allows geotechnical engineers to better analyse geological anomalies (fault orientations, dips, throw), bolting tolerances and excavation dimensions in an effective manner.
Rav Goonawardene
Geology and Geotechnical Superintendent, Anglo American – Grosvenor Mine
Ben Elliot
Trainee ERZ Controller, Anglo American – Grosvenor Mine
A series of floor heave and gas inrush events have occurred during the development mining process in MG103 and MG104 at Grosvenor Underground Coal Mine. These events have exposed coal mine workers to elevated levels of methane preventing safe mining operations.
The presence of an undrained source of gas in the immediate floor, geotechnical floor characteristics, loading environment and various other factors have contributed to the dynamic floor failure. Methane released during these events are originating from the underlaying thin Goonyella Middle Lower (GML) seam which is a thin carbonaceous layer with high ash content. The 1m – 5m interburden thickness between the GM seam and the GML has an increased likelihood of the floor gas release events.
Based on the analysis of these gas events, creating a conduit in the interburden between the GM seam and GML will allow the gas to freely release to the development roadway during development drivage. This will prevent the build up of gas within the interburden creating a floor gas release event.
The proactive interburden fracturing was initiated using water pressure generated from a longwall salvage pump. The current UIS drilling equipment was retrofitted with a series of subs, packers and a fracturing tool to initiate a hydro fracture within the drilled UIS borehole. Once the packers are fully inflated and in position, a diversion valve is then activated to allow the fracturing tool to inject high water pressure to the desired location. Thus, given the complexity of predicting verticality of the hydro fracture in the interburden, a UIS borehole was drilled in the lower section of the GM seam as proving hole to check the effectiveness of hydro fracture.
The main benefit of the proactive interburden fracturing process is having the ability to reduce the likelihood of exposing development coal mine workers at the face to high methane levels.
Grogan – Engine Bay Safe Work Platform
Peter Grogan
Glencore
Clermont Open Cut
Hanrahan – Nitrogen Foam Table
Clive Hanrahan
Operations Manager – Mine Inertisation, Queensland Mines Rescue Service
Due to the mining environments in some underground operations, particularly longwalls, where the void space in the goaf becomes wider and longer, the potential for spontaneous combustion and fire events is possible and, in some cases, has happened.
The nitrogen foam table is relatively quick to deploy, set up and become operational delivering the gas mixture to the required area. The water in-foam cools the heating whilst the nitrogen gas displaces the oxygen.
Using the nitrogen foam table supplies a medium of water foam and nitrogen gas. The water in-foam cools the heating – one leg of the fire triangle whilst the nitrogen gas displaces the oxygen – second leg of the fire triangle.
The nitrogen foam table allows for the distribution of the gas/foam mixture to either one borehole or by opening secondary valving, an additional borehole can be treated at the same time. Where a spontaneous combustion/fire event has been identified mid pillar, the utilisation of the table to treat two boreholes at the same time will greatly assist in the reduction or elimination of that event.
When drilling boreholes from the surface into underground voids the nitrogen foam table allows the gas/foam mixture to be utilised to create an inert shield whereby the foam acts as a wetting agent to prevent any incendive sparking during the drilling process & the gas displaces any potential oxygen present.
In mining areas: Such as the maingates of longwalls where there is oxygen contained within the airwash zone the gas foam mixture could be utilised to create a “plug” behind the maingate face end shields which would reduce / eliminate any airwash issues. The table can be readily located adjacent to a seal site either prior to or after the seal installation. The gas/foam mixture can be distributed from the nitrogen foam table via piping through the erected seal or hosing through the proposed seal site.
Hitz – Hastings Deering Australia Limited Field Service working at heights innovation
Travis Hitz
Hastings Deering (Australia) Limited
David Howell
Tailings and Water Coordinator, Rio Tinto Weipa Operations
Luke Pendrigh
Tailings and Water Electrician, Rio Tinto Weipa Operations
During normal operation at the Water Treatment Plant the inlet screen in the Bio Reactor blocks with debris, sludge and fecal matter. The cleaning of the inlet screen was a laborious task that exposed maintainers to raw sewage and repeated manual handling risks. The crew came up with an engineering control that completely prevented the inlet screen from blocking, eliminating the need to remove and clean the screen. With this new system functioning the crew have removed a great deal of frustration and reduced the handling of this inlet screen to planned maintenance intervals and significantly reducing the crew’s exposure to the biological risk.
Innovation award presentations, Day 2, 2022 Conference
Full session - Presentations by the five finalists selected from the first round of judging
Kahler – Pin Insertion Tool
Paul Kahler – Peabody Wilkie Creek Mine
Page 2 of 4