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Lungfish and crayfish inhabit continental ecosystems similar to those of their ancient counterparts in the Permian (lungfish) and Triassic (crayfish) Periods, exhibiting similar burrowing behaviors to live, breed, and escape desiccation. Identification of their burrows in the geologic record when body fossils are absent has relied on the overall gross morphology of the burrows and the process of elimination. A method of burrow identification has been developed by evaluating burrow structures in an attempt to designate architectural and surficial burrow morphologies that uniquely reflect the distinctive burrowing mechanism of a particular organism. The information from this method defines the burrowing signatures of an organism, enabling the differentiation of their burrows even when fossil evidence is lacking.The lungfish constructed simple, vertical burrows with bulbous terminations. The burrow walls exhibit fine, horizontal to sub-horizontal striae and vertical to sub-vertical striae near the top of the bulbous terminus, reflecting a burrowing style similar to modern burrowing lungfish. The crayfish constructed simple, vertical burrows to complex burrows with multiple branching and chamber development. The burrow surface ornamentations exhibit horizontal to sub-horizontal ridges, vertical to sub-vertical groupings of scratches, mud- and lag-liners, knobby and hummocky textures, and body impressions, which reflect the burrowing mechanism of the crayfish.

Jan 1, 1990

By Quinn P, Huuskes W

Continued extraction of the No. 3 Seam at Elouera Colliery required the driveage of a sequence of roadways within an area of significantly elevated horizontal stress. Initial roof conditions varied from excellent to very severe as the panel entered the high stress area. The variation was attributed to the extraction sequence, with different roadways "leading" the panel into the high horizontal stressfield.This paper summarises field and analytical work designed to evaluate the use of stress control methods as an effective planning tool. The "leading" roadway of the panel would be required to remain stable whilst experiencing moderate to severe deformation whilst the neighbouring roadways (stress relieved) could be driven at more acceptable advance rates using less reinforcement.The planning implications of developing the panel with stress control methods are discussed.

Jan 1, 1998

From the viewpoint of mechanical efficiency, charges should be fully coupled and, upon detonation, should just fail to break the rock in compression. But because mining thrives on its cost-effectiveness rather than its mechan- ical efficiency, the explosive which generates maximum energy per $ should generally be used, even though the mechanical efficiency of this explosive's detonation products may be sub- optimum. Wherever possible, each charge should have a length:diameter ratio of about 20 or more and should shoot to a concavely biplanar free face that is both parallel and reasonably close to the blasthole. Success in obtaining parallel effective faces often demands the drilling of angled blastholes and, hence, will require intensified research and development efforts by drilling manufacturers, especially where hard strong rocks are encountered. Blastholes should be drilled on equilateral triangular grids and fired in a Vl or shallower V-type sequence using inter-row delays which ensure that good pro- gressive relief of burden is achieved. The conventional method of calculating Se/Be values (on the basis of planar effective faces) is often invalid.

Jan 1, 1986

The Mt Sinivit gold project is located approximately 50km SSW of Rabaul in the Baining Mountains of the Gazelle Peninsula, East New Britain Province. The deposits were discovered in mid- 1983 and form part of a larger 26km long zone of variably aurif- erous quartz veining. There are no surface indications or previ- ous records of any prospecting activity or production from the region. The Mt Sinivit deposits consist of a series of oxide and sulphide reserves and resources contained in the Wild Dog (South- ern, Central and Northern oxide zones; Northern sulphide zone) and Kavursuki veins. The proposed exploitation of the oxide reserves by a series of small-medium sized open pits has been fostered by the PNG Department of Mining & Petroleum (DMP) as part of a government policy to encourage the development of a small-medium sized mining industry in the country. The aim of this paper is to document the steps and procedures involved in obtaining the grant of a Mining Lease emphasising the time and the expenditures required during each step of the approvals process for the Mt Sinivit project.

Jan 1, 1997

By Knasmillner

During blasting body wave interaction with geometrical surfaces induces Rayleigh-waves which propagate along free surfaces, e.g. crack faces or delaminated rock layers. These Rayleigh-waves carry most of their energy within a very shallow surface layer and propagate with very little attenuation in real rock materials. Upon interaction with a crack front a very strong mixed mode stress intensity factor may result and lead to fracture initiation. On the basis of experimental photomechanical results the history of dynamic stress intensity factors Kt and K2 will be studied in Detail.

Jan 1, 1990

Recovery of tin and copper from concen trates containing cassiterite, stannite and chalcopyrite was studied in laboratory-scale tests designed to simulate continuous operation of the matte fuming process in which tin is recovered as SnS fume while copper accumulates in the matte. Charges made up of 300g of mixtures of the concentrate and siliceous flux were added at a uniform rate in pelletized form to crucibles containing 300g of matte and 50g of slag (both of which were recovered from previous tests), while blowing through the matte with air or oxygen-nitrogen mixtures at a rate of 3 to 5 1/min. Accurate material balances enabled the effects of process operating conditions on tin recovery and sulfur utilization to be deter- mined. When operated correctly, the matte fuming process gave tin recoveries exceeding 90 percent in spite of wide variations in the copper content of the matte and in the operat- ing conditions. Deterioration of tin recovery was associated with undersaturation of the slag with respect to silica, and with high partial pressure of sulfur dioxide (greater than approx- imately 0.2) brought about by oxygen enrichment of the blowing air. The utilization of sulfur varied widely in low grade mattes. Copper in excess of approx- imately 10% promoted formation of SO2 by the commonly accepted reaction: FeS + 1-120 2= FeO + S02 while in copper-free and lower grade mattes a substantial fraction of the oxygen was consumed in the alternative reaction FeS + i 02 = FeO + z S2.

Jan 1, 1980

The Kidston breccia pipe is situated approximately 280 km west northwest of Townsville, north Queensland. It is currently Australia's largest gold producer with production varying between 8,000 and 16,000 tonnes of ore per day. Current reserves are estimated at 36.2 million tonnes averaging 1.74 C/t Au and 2.21 g/t Ag. Alluvial gold in the gullies surrounding the deposit was first discovered in the 1880's and between 1907 and 1948 small scale open cut and underground mining was undertaken. Advances in extractive metallurgy and an increase in the gold price were major factors influencing the recent exploration and development of large scale mining of the deposit by Placer Pacific and Kidston Gold Mines. The breccia pipe is trapezoid in shape with surface dimensions of 1100 m by 900 m. Clasts show only limited evidence of mixing during brecciation, with the pre-breccia stratigraphy still discernible on the basis of clast types. This lack of mixing together with the intimate association with intrusive activity, suggests that the brecia formed by collapse, probably associated with the escape of a large volume of irothermal fluid from a crystallising hatholith. Mineralisation and alteration are also sratially and temporally associated with rhyolite emplacement and brecciation. Pre-breccia mineralisation consists of laminated stockwork quartz veins associated with muscovite, quartz and orthoclase-epidote alteration. Stockwork veins contain either anomalous molybdenite or gold. Uneconomic early stage post-breccia mineralisation and alteration consists of cavity infill quartz-epidote and calcite associated with potassic and propylitic alteration respectively. Economic late stage post-breccia cavity infill and sheeted veining consists of quartz-carbonate-sulphide infill associated with phyllic alteration. The grade of gold mineralisation generally decreases downwards in the system with an increase in the amount of pyrrhotite relative to pyrite. Pre-breccia stockwork quartz veins mineralisation is genetically related to the

Jan 1, 1987

By Nott M. C

The oxidation of xanthate collectors to xanthate/dixanthogen results in a higher hydrophobicity of sulphide minerals surfaces due to the action of dixanthogen. This higher hydrophobicity can be proved on a fundamental level by examining the st

Jan 1, 1994

Robertson Diasol have developed a spectral gamma-gamma tool fully able to withstand borehole conditions. Spectral data is digitally recorded across 256 channels depending on energy levels of the photoelectric effect. Data processing is being developed with the objective of calibrating channel amplitudes to mineral type which will lead to a direct log of selected mineral grade as a continuous trace with depth.

Jan 1, 1990

By J Joy, D Griffiths, A Bye, G V. Kizil

Poor standards of electrical installation and maintenance continue to contribute to electrical related fatalities and injury risk in the mining industry. Electrical isolation has the potential to initiate major unwanted events (MUEs) and as such requires thorough analysis to demonstrate adequate management. There have been 719 incidents related to accidental contact with electricity over the past five years in the Queensland mining industry (Queensland Government DME, 2012a, 2012b) with the last fatality being recorded in 1997 (MESA, 2012).A project funded by the Australian Coal Association Research Program (ACARP) has developed a form of a safety case using the four-layered æCoal Mine Safety Regime (CMSR)Æ approach. The CMSR is transparent and robust as it includes full site risk assessment and special issues risk assessment to be demonstrated as part of the process.The practical application of the CMSR has been demonstrated using a longwall mining case study site, where a unique 11 kV armoured face conveyor (AFC) is in operation. The case study has involved progressive application of the requirements of each layer of the CMSR (see Figure 1) to high voltage (HV) electrical isolation related issues. The project has specifically concentrated on understanding and analysing two high priority MUEs, electric shock and unplanned movement of equipment, through Layer 1 analysis. These two MUEs are an important part of the project as they have demonstrated the steps that may be taken to satisfy the risk management processes at Layer 1 of the CMSR and have contributed to resolving issues at the other three layers of the CMSR.The analysis of HV electrical isolation has been used as an exemplar to demonstrate the CMSR process and its practical application. The CMSR is applicable to major/principal hazards management as identified by the New South Wales and Queensland jurisdictions.This paper provides an overview of the development of a form of safety case using the CMSR and introduces the case study application for HV electrical isolation risk management at underground coal mines focusing on the major unwanted event of electric shock.This project provides the mining industry with a documented, publicly accessible, form of safety case using the CMSR approach for the first time.CITATION:Kizil, G V, Griffiths, D, Bye, A and Joy, J, 2012. Using a coal mine safety regime approach to the management of high-voltage electrical isolation, in Proceedings International Mine Management 2012, pp 59-74 (The Australasian Institute of Mining and Metallurgy: Melbourne).

Nov 20, 2012

By Bradford NL

The Isa Mine of Mount Isa Mines Limited produces 2.6 million tonnes of silver-lead-zinc ore annually from sub level open stopes of which approximately 40% comes from the narrow Racecourse orebodies below 15 level.Geologically the stoping environment is complicated by highly fissile shale hangingwalls and below 17 level by a high stress regime.The realization that major hangingwall failures and generally poor ground conditions could lead to serious dilution problems, and ultimately production shortfalls, prompted investigations into the use of low strength explosives.

Jan 1, 1985

By Gooday PE, Brech GE

Ore reserve categories used by Pancontinental Mining fall into one of three fundamental groupings: Geological In Situ Reserves Mining Reserves Production Estimates The first of these describes the total reserve within stated parameters without implication as to its mineability. The second is that part of the Geological In Situ Reserve which is considered mineable under a specific mining plan. The third is the Mining Reserve adjusted with appropriate dilution and recovery factors and thus represents the best estimate of the tonnage and grade of production. This practical three category system mirrors the standard steps traditionally taken in ore reserve estimation and readily conveys the basis of the estimates. An important, but secondary classification can be added to qualify the level of confidence in these estimates using the terms: Proved (or Measured) Probable (or Indicated) Possible (or Inferred) These terms can be applied to any of the fundamental groupings, but it is generally implicit that the level of detail required to produce meaningful Mining Reserves or Production Estimates would require the basic Geological Reserve to be at a Proved or at least Probable level of confidence. The application of these classification systems by Pancontinental is illustrated by reference to the Paddington Gold Project. The methods of calculation are described including the use of geostatistics. Reconciliations of actual production with predictions from reserves are carried out monthly and annually. To date there has been an excellent correlation with Production Estimates, based on both manual and geostatistical calculations.

Jan 1, 1987

Underground mining in the West Moreton coal field started in the 1870's. Subsidence related to coal mining activities is an ongoing problem facing planners and developers in the Ipswich area in South Eastern Queensland. The history of coal mining in the area over the last 110 years has left the legacy of periodic surface instability in several areas. In general, modern engineering analysis with current mining methods combine to create predicatable analysis of surface stability and movement. Where old workings using several variations of the bord and pillar system are affected by current activity, the predictibility of the surface movement is greatly reduced. Geological complexities further complicate the analysis. Mining and the related dewatering affects the stresses on pillars in old workings. This is caused by reducing buoyancy effects caused by changes in the water levels in old workings. Of particular relevance is the depth of workings and strength of the coal and overburden. The type of subsidence affecting the surface can range from localised pillar failure, to roof failure and potholing and the likelihood of the particular form of subsidence can be assessed from studying the workings in relation to the stratigraphy and structure of the coal measure Formations.

Jan 1, 1988

By Lovitt M

Ora Banda Gold Mine is located in the Eastern Goldfields of Western Australia. Mining is carried out underground by sublevel open sloping resulting in large open stopes. A Mass Blast of approximately 250 000 tonnes was carried out in July 1994 to recover a rib pillar between two stopes, and the crown pillar between the underground mine and the abandoned open pit above. Strategic development within 50 m of the blast consisted of two ventilation shafts and the main decline. This development required careful design and prediction of the blast results. This paper describes the design of the blast, the prediction of the likely effects, the measures taken to reduce the risk to important development, and the results of the blast.

Jan 1, 1995

By Peters S. G, Beams S. D

CONCEPTS AND REGIONAL GEOLOGY The Charters Towers region holds many keys to the metallogeny associated with the complex geological development of eastern Australia during the Palaeozoic. Tectonic, magmatic and volcano-sedimentary depositional episodes can be identified and related to the chronological development of batholithic host rocks (Clarke & Paine, 1970; Henderson, 1986; Murray, 1986). Pre-batholithic basement rocks in the north (Charters Towers Metamorphics) consist of a package of amphibolite grade schists interlayered with and intruded by gabbros and diorites (Peters, 1987). To the south (Seventy Mile Range Group) greenschist facies Cambro-Ordovician rocks overly some of the basement. The lower age of this basement is not constrained, parts of it could be as old as Pre-Cambrian. Mid-Ordovician (approx. 470 my) to Lower Devonian (approx. 400 my) age I-Type granitoid plutons of the composite Ravenswood batholith intrude the pre-batholith basement and the Seventy Mile Range Group. Igneous activity was initiated again in the Carboniferous with the extrusion of rhyolitic lavas and pyroclastics associated with porphyry and high-level intrusive complexes (Wyatt et al., 1971). The Ravenswood block is bounded by Devonian and Tertiary sedimentary sequences of mainly continental provenence.

Jan 1, 1989

By M Watts, P Lindsay

Herbert Stream, a tributary of the Waimangaroa River on the Stockton Plateau, has elevated metal concentrations and low pH characteristic of acid mine drainage (AMD). Dissolved aluminium concentrations average 8.3 ppm, iron 1.4 ppm, manganese 0.69 ppm, and zinc 0.12 ppm and pH ranges from 2.8 to 3.2. Flow rates range from 2.3 to 26.6 L/s with an average of 5.3 L/s. To determine the effectiveness of different treatment strategies, a small amount of the AMD was diverted through three small-scale passive AMD remediation systems over an eight month period. These included a reducing and alkalinity producing system (RAPS), a limestone leaching bed (LLB), and an open limestone channel (OLC). Both the RAPS and the LLB performed well, effectively removing metals and restoring pH. The RAPS lowered aluminium concentrations by up to 99%, iron 97%, manganese 95%, and zinc 80% and the LLB lowered aluminium concentrations by up to 99%, iron 99%, manganese 92%, and zinc 91%. The pH was restored to between 6.4 and 7.4 by the RAPS and to between 7.3 and 7.9 by the LLB. The OLC performed well as long as the residence time was similar to that of the other treatment systems. OLC removal rates for aluminium was up to 99%, iron 94%, and manganese 21%, and the pH was restored up to 5.6. Due to its simplicity and effectiveness, it is proposed the LLB be constructed to fullscale size to treat the entire Herbert Stream.

Jan 1, 2007

By J Joy, A Bye, G V. Kizil

This paper presents an application of the newly developed risk-cost-benefit (RCB) framework to support risk management decisions for the selection of wall monitoring technologies at an open cut mine site. The RCB framework quantitatively assessed the risk of unstable slope-induced wall failure and its impact on both loss of life and coal recovery. The RCB framework was utilised in the selection of an optimum group of risk-controls to effectively manage the risk of wall failure to ensure safety and optimal production occurred. The RCB framework incorporates mathematical modules that integrated RCB calculations and risk-control effectiveness assessments to determine the risk reduction and financial impact of the examined safety initiatives.This paper provides an overview of the five-staged RCB framework, incorporating the RCB decision support tools, RCBGEN (Risk-Cost-Benefit Generator) and RCEMETHOD (Risk-Control Effectiveness Method), and demonstrates its application to slope stability risk management at the case study site. The RCB charts are designed to display a balance between risk, cost and benefit for easy interpretation by decision makers to support the objective selection of an optimum suite of risk-controls. The RCB analysis revealed that a combination of ævisual inspections, automatic extensometers and radarÆ for fast- and slow-wall failures with structure were sufficient to reduce the probability of loss of life (PLoL) to the æModerateÆ zone as defined by the Australian Geomechanics Society (AGS, 2007) for the case study site. The new framework presented in this paper provides a method to effectively determine the suitability of risk-controls and supports industry efforts to reduce risk to as low as reasonably practicable (ALARP).CITATION:Kizil, G V, Bye, A and Joy, J, 2012. Risk-cost-benefit analysis of early warning technologies impact for wall failure risk management in surface mines, in Proceedings Eighth Open Pit OperatorsÆ Conference , pp 55-64 (The Australasian Institute of Mining and Metallurgy: Melbourne).

Sep 18, 2012

By Thomas CG, Armstrong GJ, Lynch KS

A small glass walled pot grate has been used to simulate drying of iron ore pellets in a travelling grate plant. This equipment has enabled the effect of decreasing grind and de- creasing pellet bulk density on plant production to be quantitatively predicted. These predic- tions are compared with plant experience. The use of the laboratory simulator in comparing the effect of various additives on plant production is also described and substantial improvements in both the goethite and free-water drying periods are predicted.

Jan 1, 1972

By Koppe J. C

This paper describes the methodology developed to establish a sequentia mining plan applied to a coal mine, using computers. Firstly, isocontou. maps were generated from the drill holes and outcrop description information, representing the thickness and depth of the rock formation: present in the mine site. The procedure relies on the repeated application of the cross validation techniques, until the standard deviation of thi estimation is reduced to a minimum.From this map the coal reserves of the two coal seams, the overburdet (separated in hard and soft material) and the interburden were calculated After that, the maps were transferred in digital files to AutoCAI software, where different mining plan simulations were performed. 7b ore evaluation in each case was done automatically, including tonnages volumes and stripping relations. The final mine configuration consider the economic aspects of the operation.

Jan 1, 1993

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