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By Evans A, Jones O

Surface subsidence resulting from "total extraction" of coal in the Collie Basin first occured in 1987 when Western Collieries Ltd trialled the Wongawilli mining method. Because very little quantitative subsidence data existed for the weak, Permian sediments, a research program was set up prior to the extraction of the first panel. The objective of the study was to be able to predict subsidence characteristics and effects prior to mining future total extraction panels. Attempts at predicting subsidence began using existing subsidence models from other coal mining regions, however, as more site information became available, it became clear that it was necessary to develop a separate, she specific predictive model for the Collie Coal Basin. Analysis of extensive field monitoring data for both surface and subsurface subsidence has produced a series of empirical models which can predict the shape of surface subsidence troughs and corresponding tilts, and strains for rectangular panels and describe the sequences of ground movement from the mine roof through to the ground surface.

Jan 1, 1992

By Fejes A. J

The U.S. Bureau of Mines installed surface and subsurface instruments at a mine site in Colorado to monitor and characterize the overburden response to longwall mining. Instrumentation included a time-domain reflectometry (TDR) cable, a multiple-point borehole extensometer (MPBX), vertical- deformation surface monuments, and in-mine pressure cells for monitoring abutment, pillar, and gob loads with respect to the longwall face position. The purpose of the study was to collect data that could be analyzed to correlate the design of the mine layout to the resulting overburden failure response. Determining the extent of caving and fracturing is important in the and and semiarid Western United States because of the possible consequences to the fragile underground hydrologic systems upon which the land owners and users depend. This study is unique from past investigations because the overburden contains massive sandstone members that impose special conditions on the caving process and pressure redistribution above the longwall panels. This paper presents the results of this correlation study.

Jan 1, 1992

By Hochwimmer B, Baxter JL

Heavy minerals are mined from two fossil strandlines on the southern Swan Coastal Plain. The Capel shoreline, 7 km inland, and the Yoganup shoreline, 15 km inland are arcuate, northwest-facing, and remote from the modern coast. Based on foraminiferal and molluscan assemblages, the shorelines are probably of Pliocene age. The Yoganup shoreline is adjacent to the Whicher Scarp, which is cut into the Leederville Formation (Lower Cretaceous) at the southern boundary of the Swan Coastal Plain. Stratigraphic relations and detailed sedimentology have been studied from temporary exposures in the Yoganup Extended and Yoganup North mines, within a strandline complex at 27 m and 18-33 m above sea level respectively. Heavy minerals were deposited in thin, shallowing-upward sequences along a wave-dominated clastic shoreline cut into pre-Cainozoic sediments. Lithofacies units deposited in eolian, foreshore, shoreface and lagoonal environments are the most significant sites of heavy mineral accumulation. The data collected provide a basis for further exploration.

Jan 1, 1986

By Jensen B, Ofori P, He Y, White E, Stanmore B, Brien M, O&apos

As part of a large AMIRA project, an on-line moisture meter was installed at two mine sites in Central Queensland. This project investigated the factors which control the moisture content of coarse (>0.5 mm) coal from the centrifuges used in conventional coal preparation plants. It was placed immediately after the first centrifuge to isolate the factors pertaining to one machine and its feed.The meter was found to be accurate and precise when compared with manual and mechanical sampling methods. The Grubbs estimator technique indicated that its precision is better than 0.3 per cent at the 95 per cent confidence limit.It has been identified that:1. the variability of the measured moisture contents of coarse coal can be described by normal distributions. Standard deviations of about 0.6 per cent are common; and2. the treatment of the coarse coal on the drain and rinse screens immediately prior to the centrifuge can affect the final moisture content.

Jan 1, 1995

The Fraser Range is composed dominantly of basic pyroxene granulites derived from basalts, many of which appear to have been vesicular and*pillowed. Acidic and basic garnet-bearing granulites are important in the west, and acidic granulites and narrow anortho- site layers are dominant in some regions east of the Fraser Range. An extensive flat-lying olivine gabbro sheet cuts the granulites, and in places has been converted to spinel-bearing meta-gabbros and pyroxene granulites. The granulites of the Fraser Range (Proterozoic) are separated from the gneisses and schists of the Goldfields regions (Archaean) by the Fraser Fault, over which there is a large gravity anomaly (gradient 20 milligals per mile). Some of the problems associated with the concentration of Cu, Ni, etc. liberated from mineral lattices during metamorphism, and other principles of metal concentration in granulite terranes, are discussed. The recognition of vesicular and pillowed zones, even though highly metamorphosed, is of fundamental importance.

Jan 1, 1969

By Hinde J. S

The Fitzpatrick Orebody is a three and a half million tonne fault bounded portion of the early-middle Proterozoic Broken Hill Orebody.The Fitzpatrick Orebody was discovered in 1975 by diamond drilling from the 36 Level Exploratory Drive. This followed persistent geologically oriented exploration and a courageous decision by mine management to deepen No. 3 Shaft to provide exploratory development across the Globe Vauxhall Shear and allow effective drilling of the target area.The stratiforrn oebody consists of three lenses, the lead rich No. 2 and 3 Lenses and smaller zinc lode. They represent a down plunge extension and boudinaged, fault-bounded portion of the main Broken Hill ore lenses. The surrounding host rocks are extensively faulted and jointed due to complex history of movement on the bounding shears. This results in extremely poor ground conditions during mining. The ore was delineated for mining development using three dimensional fan drilling from exploratory and hanging wall drive drill sites.

Jan 1, 1990

The mining of remnant coal reserves at the Liddell Open Cut is subject to a number of risks. These risks are of both a technical and financial nature. Liddell Open Cut is principally a conventional truck and shovel/loader operation, supplemented by a highwall coal augering operation. There are significant areas of divergence from more conventional operations including working in close proximity to a major dam, working up dip from an operating underground mine, and working through areas where there has previously been underground extraction. In addition the site has major long-term rehabilitation requirements. This paper, rather than concentrating on specific detail of areas of risk, presents the spectrum of geological, design, operational and post-mining risks that accrue to the various areas of activity in this open cut operation. The balance of this paper then provides an outline of the strategies employed by Liddell Coal to manage their potential impact.

Jan 1, 1994

By Cox LT

A short term tyre study of trucks operating in a multiple pit surface coal mine showed significant potential for cost savings. The tyre study, conducted on-site over a three months period covered a mixed fleet of 18 trucks ranging from 27 tonne to 77 tonne capacity operating on overburden removal, coal haulage and watering duties. Some existing plant history records and a variety of tyre related measurements during the course of the study allowed the current state of tyre operations to be quantified. Specific attention was given to determining ger>ral trends from historical records and conducting detailed studies of individual lug damage, pressure monitoring and rectification, as well as tyre maintenance procedures. Important haul road parameters including camber, gradient, curve radii and superelevation, constructional materials and surface clean-up were appraised for their influence on tyre wear. Recommendations for achieving long term cost effective tyre utilisation included increased tyre maintenance, personnel development, compliance with haul road design parameters and more stringent clean-up Procedures.

Jan 1, 1982

By Richmond A

Like many industries the coal mining industry has, since the beginning of this century, undergone many changes. Technological advances and the increasing demand for fossil fuels have introduced new mining methods and techniques which allow the extraction of thicker and deeper coal seams at higher rates of production. Most new methods of mining (or for that matter any other processes) introduce problems which the engineers of the industry are expected to face and resolve. Unfortunately, spontaneous combustion has plagued the coal mining industry since the first attempts to mine coal, and is no doubt partly responsible for the reputation that coal mining is a hazardous industry. The financial loss and toll of human lives due to the occurrence of spontaneous combustion of coal in coal mines is enormous, if not incalculable. Its occurrence today is less likely to claim lives, due to both improved methods of working and in the detection of spontaneous combustion sites.

Jan 1, 1983

Long-range side-scan sonar and conventional geophysical data for the Peru Trench region (8`S-15¦S latitude) have been analysed. The data show that the Peru Trench is a site of sediment subduction where bending-induced normal fault-ing of the Nazca plate plays a key role. The sediments are continually removed from the trench axis region by their inclusion in normal fault-defined void spaces, such as grabens. In the process of subduction, the sediments are often offscraped, folded arid kneaded temporarily at the base of the shoreward trench slope. The subduction complex comprising such sediments is narrower than 20 km and its volume remains more or less constant due to regular removal of its contents along with the down-going plate. Addi-tionally, morphology of the subducting Nazca plate is responsible for subduction erosion of the South American plate, where the horst blocks cause tectonic erosion by abrasion and the grabens provide a mechanism for removal of the eroded material.

Jan 1, 1990

The initially cautious approach taken towards ground support and reinforcement at the Porgera Underground Gold Mine in the Highlands of Papua New Guinea has evolved rapidly in the two years since stoping commenced. The confidence to continue the evolution process has grown from an increasing knowledge of mining conditions as stoping has progressed, to the extent that reinforcement requirements have decreased by 50 to 75 per cent depending on local circumstances. Changes to mining practices have significantly assisted and influenced this process.Empirical observations of ground behaviour, assisted by a deliberately selective extensometer monitoring program, provided the stimulus for early changes to ground support and reinforcement practices. Further optimisation of the ground support and reinforcement effort is being pursued through an active monitoring, measuring and analysis program. Ultimately, situation rather than site specific design will ensure continuing high quality ground support and reinforcement installations. However, local structural and lithological factors will continue to become more critical as the optimum position is reached.

Jan 1, 1993

By Moffatt G

Approval to operate Longwall No. 7 at Appin Colliery in 1979 was granted pursuant not only to the usual statutory provisions, but also that an adequate means of drainage of methane gas be incorporated. A methane drainage plant was subsequently designed and constructed some two km from the pit top at the site of the Colliery main upcast and down cast shafts. Modern plants of this nature are completely automated using programmable controllers and computers to provide control and management reporting functions. Complex mechanical systems are installed to extract the gas and in handling and storage processes. Gas utilisation plants exist which can generate power from methane. These plants are further enhanced by harnessing waste heat produced in the generation process. The installation, automation control and monitoring of these plants incorporates many facets of engineering from high voltage power supply and computer technology to complex gas handling procedures used in gas compression storage.and generation of electric power.

Jan 1, 1982

Silver-lead ores are widely distributed through- out the Mount Lofty and Flinders Ranges, but none of the deposits is large. Historically the Glen Osmond Mines are the most significant as the site of the first metalliferous mining in Australia, but Talisker was one of the three largest producers of silver-lead in a state whose mining history is dom- inated by copper. The mine is located in a magnificent natural setting on Talisker Conservation Park, near Cape Jervis, southwest of Adelaide (Figure 1). It is exempt from the operations of the Mining Act and listed on the Register of State Heritage Items. The mine and associated township of Silverton were dominated by Cornish influences during the period of principal activity between 1862 and 1872. Silverton, located on a ridge overlooking the mine, grew to a population of about 300 at its peak in 1870 and the area was very much another 'little Cornwall'.

Jan 1, 1987

By T Amiconi

Ernest Henry Mining commenced operations on its copper-gold project in August 1997, some two months ahead of schedule and ten per cent ($35 million) under budget. The mine is located in the highly prospective Mount Isa/Cloncurry mineral district in north-west Queensland, approximately 38 km north-east of Cloncurry. The developer and operator of the project is Ernest Henry Mining Pty Ltd (EHM), an incorporated joint venture between MIM Holdings Limited (51 per cent) and Savage Resources Limited (49 per cent). The deposit is located approximately 40 km north of Cloncurry in North West Queensland and lies beneath a featureless black soil plain with no significant creeks or gullies cutting across the site. Vegetation is sparse and consists essentially of Mitchell grass with occasional low shrubs and trees. Up to nine million tonnes of ore and over 43 million tonnes of waste will be extracted each year from an open pit operation to produce approximately 350 000 tonnes of concentrate when in full production.

Jan 1, 1998

By G J. Showers, P Botman, A G. Hunt

Iron Road Limited (Iron Road) is currently evaluating the feasibility of producing 21.5 Mt/a of high-grade (>66 per cent Fe) magnetite concentrate from a 3.7 Bt resource (JORC) located at Warramboo on the central Eyre Peninsula in South Australia. Bulk concentrate can be produced via a conventional grind and low-intensity magnetic separation flow sheet. Due to the comparatively coarse magnetite liberation size (106 µm), consideration was given to enhancing both the grind economics and coarser product sizing via gravity separation.This paper outlines the test work, flow sheet design and engineering design of a gravity beneficiation circuit (GBC) conducted by Mineral Technologies for Iron Road. The resulting circuit optimisation necessitated mass balance simulation by Iron Road’s SysCAD model to quantify the resulting changes in mill recirculation load. This included the determination of project-critical grinding power and energy requirements with and without the GBC installed into the primary ball mill classification circuit. The outcome of this work was the design of a GBC, including spirals and up-current classification, which led to a substantial reduction (33 per cent) in ball mill recirculating load and power requirements, together with a favourable coarsening of final product size due to the relatively coarser gravity concentrate. This has led to a significant reduction in project design capital and operating costs. A further benefit of this approach is increased recovery of (paramagnetic) hematite and lesser titano-hematite via gravity separation compared to an all-magnetic separation approach.CITATION:Hunt, A G, Showers, G J and Botman, P, 2015. Test work and design of a gravity circuit for Iron Road’s Central Eyre Iron Project, in Proceedings Iron Ore 2015, pp 139–142 (The Australasian Institute of Mining and Metallurgy: Melbourne).

Jul 13, 2015

By R Berry, S G. Walters, J A. Hunt, D Collett

The texture of an ore type is fundamental in understanding the metallurgical behaviour of an ore. This study will show examples of how quantified textural attributes (mineral shape, grain size and mineral association) can be obtained from automated and scanning electron microscope (SEM)-based microscopy and utilised using advanced image processing techniques. Examples will be shown of integrating quantified and semi-quantified meso- and macro-scale textural attributes as well as how they relate to texture-based visual logging systems. The implications of texture for processing behaviours such as comminution, liberation and recovery will be discussed. This research is part of a major collaborative geometallurgical project undertaken at the Centre of Excellence in Ore Deposits (CODES, University of Tasmania) and the Julius Kruttschnitt Mineral Research Centre (JKMRC, University of Queensland). The authors wish to acknowledge financial support and permission to publish from the sponsors of the AMIRA P843 GEMIII project.

Jan 1, 2008

The Louvicourt Mine is located 600 km north of Montreal in the province of Quebec, Canada. The owners are Aur Resources Inc (30 per cent), mine operator, Novicourt Inc (45 per cent) and Teck Corporation (25 per cent). It is an underground mechanised operation with a total work of 290 employees. Since 1994, the mine production is 11 120 456 tonnes at 3.60 per cent Cu, 1.51 per cent Zn, 26.07 g/mt Ag and 0.96 g/mt Au. At a rate of 4300 tonnes per day 365 days per year. Louvicourt Mine is a copper operation since 80 per cent of our revenue is from copper. The mining method is transverse blasthole stoping, mining primary and secondary stopes. The stope dimension is 15 m wide by 30 m high and 10 m to 80 m long for primary stopes. The secondary stopes are limited at 25 m long. Close to 100 000 metres of production drilling per year is required for 115 mm and 165 mm diameter holes. Backfilling is done with pastefill from the start of the operation in 1994. The binder ratio is 4.5 per cent in primary and two per cent in secondary stopes (80 per cent slag and 20 per cent cement). Development requirement to maintain production was 5000 m from 1996, 1997, 1998, 4200 in year 1999, 3200 m in year 2000 and an average of 2500 m in 2001 and 2002. Typical 6.0 m + 4.3 m, 4.9 m + 4.6 m and 4.5 m + 4.6 m headings. In addition more than 1500 metres of development will be excavated in/under paste backfill before 2004. A total of 60 mobile units are required among which for lateral development (three two boom electric hydraulic jumbos û AC Boomer 322, four electric hydraulic roofbolters û Maclean MEM-928 and AC Boltec PL350 and two anfo loader truck û Dux) and for production (four ITH drills û MTI, one electric hydraulic longhole drill û AC Simba H1357, eight LHD û AC-Wagner ST8-B, 1 LHD ST-1000 and two haulage 30 tons trucks û Dux. The 1 January 2002 reserves are 4.1 M tonnes grading 3.1 per cent Cu and 1.9 per cent Zn at an NSR (Net Smelter Revenue) of $US 53. The operating mining costs were at an average of $US 23 from 1996 to year 2000 and $US 25 in 2001. The operating costs ranged from a low of $US 0.41 per pound of copper in 1999 to a high of $US 0.49 per pound of copper in 1998.

Jan 1, 2002

By R Burke, G Ramage, C Donnelly

Over the decades, Redpath has undertaken a multitude of tunnelling and underground excavation projects for civil and mining clients both domestically and internationally. These projects have been undertaken through varying strata conditions with differing excavation methods in remote locations and in central business districts.With the recent turbulent nature of the global financial environment, project drivers have been challenged with the emphasis being placed on methods to gain early access to orebodies, rapid development techniques, lower capital costs and reduced labour requirements to name a few.A number of mining companies seeking to achieve these objectives have commenced the journey to better understand the operational constraints, challenges and opportunities that may be available with the use of alternative excavation methods.The development of safe and effective alternative excavation methods that comply with both domestic and international mining legislation and regulatory requirements is a challenge the industry needs to embrace. Given the current cost pressures being faced by the Australian mining industry, some alternative excavation methods offer the potential for longer term sustainability and rapid development of resources.More recently work has been undertaken on a project that challenged the norm and implemented an alternative excavation method with the use of an excavator with a rotating drum cutter head.This paper will review this recent project and provide technical and operational insight into some of the challenges faced in implementing an alternative excavation method in the metalliferous industry.CITATION:Donnelly, C, Ramage, G and Burke, R, 2014. Challenging the norm – alternative excavation method in mining, in Proceedings 12th AusIMM Underground Operators’ Conference 2014 , pp 187–190 (The Australasian Institute of Mining and Metallurgy: Melbourne).

Mar 24, 2014

By P Dean, M Elmouttie, Y Duan, X Luo

Slope instability is one of the major concerns in open pit mining operations. A significant collapse of the pit wall can result in injuries, damage to machinery and interruptions to production. A broadband microseismic monitoring technique has been developed for diagnosing the healthy condition of a target slope area. This technique has been successfully applied to an open pit mine in Chile. Our research has found that this microseismic monitoring technique can be used in open pits for tracking and locating a falling rock that is rolling on a slope, if a dedicated seismic sensor network has been established. In collaboration with other monitoring techniques (radar, laser scan, aerial photography), more accurate determination of rock rolling trajectories can be obtained. In this paper, an example of using the CSIRO microseismic monitoring technique at an open pit mine is presented. Results from an experiment where we used the microseismic technique for determination of the trajectory of a rockfalling on a slope are also presented.

Nov 8, 2021

By J Player, P Mikula, G Sweby

A numerical modelling back-analysis exercise was carried out at a WA gold mine at which early signs of seismicity (rock noise, scatts from active faces) were becoming apparent as depth of mining increased towards the 500 m mark. Some strain bursting had occurred and it was necessary to discover what the implications of this were for greater depth. The aim of the modelling was to: 1. Establish a correlation between observed ground conditions and model predicted damage, in overstressed areas of the mine. 2. Use this correlation to forecast rock mass damage and ground control requirements for proposed future stoping panels at greater depth. Good correlation has been achieved between observed rock mass damage, and a 3D Finite-Element RS3 model, run in elastic mode. Two candidate stress field orientations were modelled. The model parameter best fitting the observations was the Strength Factor (SF), the ratio of strength/stress. The good match (correlation coefficient of 0.7) between observed and modelled suggests that the elastic approach is justified for the depth range and rock mass properties analysed. The correlation also enabled a link between observed damage and installed ground support performance. Using the linear best-fit between observed and modelled, a forecasting exercise was carried out using the same RS3 model, modified to include future stoping. The resulting damage and ground support categories were obtained from the modelled SF for each proposed stoping level. Also, a series of generic geometries was assessed to investigate the impact of varying stope face lead/lag distance, sill pillar height and stope pillar size, on ground conditions. The key finding of the generic geometries were: • Ground support schemes have been defined for the expected conditions. • All ore drives are expected to have significant damage in the backs and rehabilitation. • Lead/lag distance not to exceed 10 m. • Sill pillar/level intervals of less than 20 m require an increase in ground support scheme. • Pillar sizes for maintaining footwall and hanging wall stability should be at least 10 m × 5 m.

Nov 29, 2022