Journal of Mining Science 46(3),2010, 280-297, A REVIEW ON EXISTING OPENCAST COAL MINING METHODS WITHIN AUSTRALIA (original) (raw)

A review on existing opencast coal mining methods within Australia

Journal of Mining Science, 2010

Currently almost 65 % of the coal in Australia is being produced by opencast mining methods. Mining equipments such as draglines, dredgers or bucket wheel excavators, trucks and shovels, and dozers are the main equipments employed for overburden removal and coal extraction. The choice of equipment for a particular mine depends on geological, geotechnical and economic factors and other site issues. This paper provides a general review of the main equipments used in Australia, including examples of some existing mines and the reasons for their choice of equipment. In addition, the paper discusses major geomechanical issues encountered and how these may influence the selection of appropriate equipments used in open cut mining operations.

Geological and geotechnical aspects of underground coal mining methods within Australia

Environmental Earth Sciences, 2010

About one quarter of the coal produced in Australia is by underground mining methods. The most commonly used underground coal mining methods in Australia are longwall, and room and pillar. This paper provides a detailed review of the two methods, including their advantages and disadvantages, the major geotechnical and operational issues, and the factors that need to be considered regarding their choice, including the varying geological and geotechnical conditions suited to a particular method. Factors and issues such as capital cost, productivity, recovery, versatility and mine safety associated with the two methods are discussed and compared. The major advantages of the longwall mining method include its suitability for mining at greater depth, higher recovery, and higher production rate compared to room and pillar. The main disadvantages of the room and pillar method are the higher risks of roof and pillar collapse, higher capital costs incurred as well as lower recovery rate.

Dragline Digging Methods in Australian Strip Mines - A Survey

1998

Open cut mining in Australia is facing the greatest challenge in its hilstory in attempting to compete not only with other operations internationally, but also with underground operations domestically. Most flat dip and shallow depth surfacemineable coal reserves have been depleted during the last two decadc:s and new open cut operations must extract deeper coal deposits. As open cut coal mines move into deeper areas andl the stripping ratios increase, the relative cost of overburden removal also increases. It therefore becomes even more important to design the mine around the optimum overburden removal scheme. The deeper mines are usually multi-sc:am operations with a more complex geology and with more geotechnical and hydrological problems. Deeper mines are subjected to greater problems requiring more detailed mine planning and design, such as selection of the optimUJm mining method and pit layout. In planning and design of such operations, the number of alternative methods which ...

Developments in open cut mining

The Australasian open cut mining sector is dominated by iron ore, coal and gold producing operations. This has been so for the past 20 years. The total production from these mines has changed over the past 20 years, as follows:

Proceedings of the 2011 Coal Operators' Conference

2011

Mining commenced at Tasman Mine in late 2006. The current method of mining is bord and pillar using continuous miner-bolters and shuttle cars for first workings and secondary extraction using breaker line supports. The two stage process was chosen to accommodate irregular shaped coal deposits, allowing adjustments to be made to extraction ratios for better management of subsidence and to maximise the efficiency of the operation. Following the completion of the first three full/partial extraction panels a change in mining method was undertaken due to variable caving. The adopted partial extraction method involves stripping the developed square pillars on four-sides on retreat to leave a load-bearing remnant coal pillar. The system of partial extraction has been successful in delivering safety, productivity and subsidence targets.

Proceedings of the 2014 Coal Operators' Conference

2014

On behalf of the organising committee I welcome you to the 14 th Coal Operators Conference (Coal2014).The duration of the conference has been extended for three days because of the increasing number of good quality and innovative papers presented. 42 papers out of a total of 49 will be presented on topics covering both surface and underground mining, and includes papers on geology, geophysical logging, geotechnical engineering, rock fracture mechanics, general ground control, heading development, longwall mining, pillar design, information technology, rock cutting and rock bolting, mine ventilation, mine gases and fugitive gas emissions, outburst control, mine safety and risk management. A number of Australian mine operators, consultants, research organisations and academics are show-casing their cutting edge research findings in the conference.

Application of continuous mechanical cutting to coal overburden removal

2020

Conventional overburden removal in coal mining is typically achieved using drill and blast. However, drill and blast is a cyclical (or batch) process that has inherent inefficiencies and offers limited opportunities for enabling automation technologies. Existing mechanical rock cutting systems such as surface miners, continuous miners, roadheaders, impact hammers and tunnel boring style machines are commonly applied in underground excavation environments and also in some mining operations. Most of these technologies are based on pick-based machines, mechanical indentation and hammer impact. A review of industry literature and OEM data indicates that beyond rock strengths of about 40MPa UCS, the cutting cost for pick-based systems escalates exponentially due to high pick consumption rates and low machine productivity. However, with the emergence of undercutting with oscillating discs (developed by Joy Global as DynaCutTM), potential exists for economic mechanical excavation spanning ...

Coal mining trends, approaches, and safety hazards: a brief review

Arabian Journal of Geosciences, 2018

Coal is the vital source of energy in world and is a burnable brownish black or black sedimentary rock contemporary in the rock strata in form of layers; thickness of layers may vary. It is available in all over the world in large quantities and can be extracted to be utilized as energy-producing source to fulfill the energy demand. There are two modes of mining: (a) surface or open pit mining and (b) underground mining. The method of excavation adopted depends on a number of factors including depth of deposition and inclination angle of the coal seam. The workers involved in this operation are prone to more risk than the workers who are involved in other operations. Miners face numerous problems in the process of underground coal extraction such as high temperature, humidity, coal and silica dusts, harmful gases, the rock stresses, and the disturbance due to extraction that causes failures. These problems cause injuries, multifatalities, and major asset losses until precautions are taken to control these problems. Coal mine failures are affected by various factors such as geological and structural parameters. The in situ conditions of the rocks in the coal mines are disturbed due to excavation and extraction of coal. In order to stabilize the roof as well as walls of the coal mines, different techniques are used. The most common techniques of supports in coal mines include can support, pump-able roof support, cluster prop, timber support, prop, shotcrete, wire mash, and rock bolts.

Advanced directional drilling technology for gas drainage and exploration in Australian coal mines

Procedia Engineering, 2011

With the continuing technology innovation, directional drilling technology has provided the coal mining industry with effective and practical options for pre-and post-drainage and exploration in Australia. In the past thirty years, in-mine borehole steering equipment has been developed from the single shot camera survey systems to the advanced Directional Drill Monitor utilizing Modular Electrically Connected Cable Assembly (DDM-MECCA) survey instruments, which provides rapid and easy underground borehole survey measurements whilst drilling. The presence of coal seam gas such as methane poses a significant safety hazard to underground coal mining all over the world. However, gas can be captured using pre-and post-drainage techniques to improve coal production, energy recovery, enhance safety, environmental mitigation. An additional benefit of directional drilling is geological explorations in advance of mining. As any discontinuities intercepted during in-seam directional drilling, such as faults, folds and igneous intrusions, can be monitored by drilling fluid pressures, changes in thrust, vibration, rate of penetration and inspection of cuttings. Directional drilling technologies offer coal operators a cost effective exploration alternative without speculation. Applications of the directional drilling technologies in Australian coal mines have established the benefits of the methodology for gas control and geological explorations. Directionally drilled flank boreholes provide shielding to the gate entry developments, horizontal goaf boreholes for gas drainage in deep multi-level mines, and hydro fracturing and exploration in advance of mining. However, there still remains four major problems associated with directionally drilling, and these include: sticky drilling in complex conditions, sensitivity of down hole probe, in-hole stability and drill depth capacity.

Proceedings of the 2004 Coal Operators' Conference

2004

The underground coal operators conference series held annually in Wollongong has been recognised as the main form of the exchange of ideas between mine operators, engineers and researchers in the diverse field of coal mining technology. For the last five years the conference addressed a variety of issues, focusing primarily on underground ground control and mine safety. In order to increase participation, attention has now been drawn to addressing various other issues in addition to ground control. The theme of Coal2004, Mine Planning demonstrates the true interest of the conference in promoting high output longwall operation. This year the conference is preceded by a halfday workshop on mine subsidence and surface environment impacts.