Report: APP CMHS Project 1




CSIRO advises that the information contained in this comprises general statements based on scientific research. The reader is advised and needs to be aware that such information may be incomplete or unable to be used in any specific situation. No reliance or actions must therefore be made on that information without seeking prior expert professional, scientific and technical advice. To the extent permitted by law, CSIRO (including its employees and consultants) excludes all liability to any person for any consequences, including but not limited to all losses, damages, costs, expenses and any other compensation, arising directly or indirectly from using this publication (in part or in whole) and any information or material contained in it.



3.1.14. Automation of Development Mining

The automation of development mining processes is more complex than that of Longwall mining. As the process relies on four separate and distinct phases – cutting, supporting, ventilating and conveying; there is a need to automate and ultimately integrate each one. Each has been automated to varying degrees individually and some have been integrated, but not automated.

The value of automating the respective phases has differing benefits from a safety perspective compared to production. Automation does not always yield a production benefit, though with time and development this should occur.

  • Automation of the cutting phase removes persons from the face environment – reducing exposure to airborne dust, potential strata failure and more critically from potential outburst occurrences.

  • Automation of the support cycle removes people from unsupported roof/rib areas and the dangers associated with interaction with hydraulic equipment. The challenge is to integrate the steps of drilling, installing straps or mesh and installing and anchoring the bolt. This is also the major bottleneck in development productivity, particularly in deep highly stressed mining conditions, where the installation of a significant amount of support may be required.

  • Coal conveyance is traditionally by shuttle car or ram car. Automation of the conveyance process will reduce the risk at the person/machine interface, which continues to maim or fatally injure many miners in all underground coal mining countries.

  • Ventilation is typically a non-continuous process of extending ventilation ducting from an auxiliary fan to the advancing face area, exposing workers again to the newly exposed strata. Similarly the extension of face services such as electric cables, air and water is a manual or semi-automated process at best.

Cutting

Recent trends in roadway development machinery automation have resulted in the implementation of remote controlled continuous miners that allow the operator to be positioned metres from the face often near the shuttle car operator. However, this has also meant that the operator is not able to closely observe the cutting horizon. Integrated support systems and machine stabilisation combined with sumping characteristics have reduced the variability in cutting horizon in some machines, whilst others have provided a spatial orientation system that is periodically calibrated. This is fairly standard technology and is readily available on currently supplied continuous miners. Current technology of miner/bolters that can continue to cut using a sumping head, whilst bolts are installed continue to be improved and include temporary roof supports that assist the installation of the support and provide additionally safety for bolter operators.

A more critical issue with regard to roadway development is that of providing a more uniform roadway profile – normal practice is to follow the seam gradient, often resulting in undulating or even stepped roadways. Mining to a more even profile, using predetermined survey controls and inertial navigation systems, and reducing the potential seam rolls reduces direct operator injury in personnel transport and latent injuries through exposure to repairs and maintenance of damaged equipment. E.g. shuttle car damage from driving over steps or severe grades, conveyor wear through following undulations and placing additional stress on tensioned components. The ultimate objective being to fully automate the cutting and loading cycles (including in breakaways) enabling remote operation.

Miners such as the ABM25 and Joy 14ED25 provide cut and bolt capability with the greatest potential for further automation and removal of personal exposure at the face.

Video camera technology has been trialled in some instances, but normally for the express purpose of removing personnel from the face zone when mining in known or suspected outburst zones. The resulting productivity is poor, but mainly due to the limitations imposed by the outburst control measures rather than just the technology.

Demonstration of this apparatus is primarily restricted to the Bulli Seam mines in the Illawarra Coal Measures in New South Wales. It is not often used due to the underlying hazard of outburst conditions, which are aimed to be avoided by implementing elimination control measures – i.e. gas drainage. Mines such as BHP Billiton’s Appin and West Cliff Collieries have predominantly utilised such apparatus.

Scope exists and is under consideration for the application of traditional tunnel boring technology as a means to provide a more inherently stable roadway and integrated roof support systems. Whilst this is still some way off, the technology is clearly in place, it is a case of matching economics with productivity; and providing answers to flexibility issues such as the provision of cut-throughs (Cross-cuts) and rapid relocation of the entire unit.

Strata Support

Current design of machine mounted, hydraulic, strata support installation systems whilst far better than the previous hand held, manually operated compressed air roof bolters; still exposes the operator to the unsupported face area and potentially high airborne dust atmospheres. It has also generated a much higher incidence of debilitating hydraulic oil injection injuries. The support process is highly dependent on input and interaction from the bolter operator. This is largely because of the individual and separate requirements of the support process - to fit drill rods into the drill rig, remove the drill rod, insert chemical anchors, insert the roof/rib bolt, and operate the drill rig directly to drill the hole or tension the bolt. The metalliferous sector however, has for sometime had modular type drilling and bolting machinery that can be operated from within the safety of a drilling jumbo – this technology has not been able to be applied to the coal sector to date. However, recent developments in self-drilling bolts now mean that the full automation of the support process is becoming more conceivable. A four carousel self drilling bolter, utilising AFX units, has been developed by Joy mining for commercial operation. Self-drilling and single pass bolting applications are operation at Mandalong and Broadmeadow Coal Mines

Recently researchers and continuous miner OEMs commenced working together on developing a prototype that automates the process of loading, positioning and installing roof and rib bolts. The design will work with different types of bolts, including self-drilling bolts. It will also look at alternatives for automatically installing mesh, including automated spraying systems for liquid mesh. Spray polymers have been applied in other support installations and have been trialled in underground coal mining, though not on full production scale. The project is being funded by ACARP and coordinated by the University of Wollongong and is scheduled to trial a prototype by YE2010.

Coal Conveyance

The third critical component of roadway development automation is that of haulage of the coal from the face. This process is currently constrained by the use of shuttle or ram cars. This equipment not only creates a significant person/vehicle interface hazard, it also limits the automation potential. There are however, a number of continuous haulage systems available, typically in the USA, that effectively resolve this issue. The challenge is to integrate the systems with the automation/remote operation focus.

Ventilation and Face Services

Monorail systems that contain all ventilation and services have been successfully operated albeit in a semi-automated configuration. Scope is now in place to make these semi-automated. They typically operate with a separate monorail system to the face that is attached to the continuous miner with auxiliary fan suspended from the monorail so that the entire apparatus advances and retracts with the machine. The other option is to install the vent line on the bridge conveyor so that as it snakes forward, it carries the ventilation tubing. The fan also moves forward with the bridge conveyors. At least two systems are currently installed: Cook Coal Mine and Mandalong Coal Mine.


APPgate Quick Search


APPgate Partners

APPgate is a collaborative effort of many of the coal producing nations of the Asia Pacific Region:


Australia


Canada


China


India


Japan


Republic of Korea


USA

 


©2018 APPgate