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By D Cliff

Despite advances in technology, the Australian underground coal mining industry continues to have incidents involving spontaneous combustion. Managing these incidents relies heavily on understanding the state of the event as it develops and controls are applied. Gas analysis plays a major role in aiding this interpretation. This interpretation is based upon laboratory testing of coal samples under conditions very different to those found in an underground coal mine. This paper will explore the links between laboratory data and actual events. It will highlight the difficulties of using laboratory data. It will outline the relevance of laboratory data and how it can be usefully applied to manage spontaneous combustion events as well as in establishing relevant trigger action response plans to facilitate early detection and control of such events. The paper will identify some of the factors that need to be applied when adapting laboratory data to apply to the underground coal mine. It will outline the need for comprehensive knowledge of the local conditions and gas concentrations to be expected at all locations in an underground coal mine. Further, it will demonstrate the need for mine environment monitoring to go beyond simply measuring gas concentrations but also to include reliable atmospheric pressure, temperature and air velocity monitoring.CITATION:Cliff, D, 2013. Gas analysis - Linking the laboratory with reality, in Proceedings The Australian Mine Ventilation Conference , pp 277-282 (The Australasian Institute of Mining and Metallurgy: Melbourne).

Jul 1, 2013

Consideration is given to the factors affecting raceway activity and the hearth design of a zinc-lead blast furnace. Results of measurements made on operating furnaces are given and comparisons are made with published data both from operating iron blast furnaces and from dynamic models of the zinc-lead blast furnace. Indication is given of the methods used for assembly of the relevant information into the specification of a commercial furnace design. A discussion on the comparative merits of furnaces of circular and essentially rectangular plan is given based on the concepts explained in the paper.

Jan 1, 1981

External pressures are being exerted on busi- ness, and especially the mining and energy in- dustries, as never before. These pressures are burdensome, they emerge in unique forms, and they constitute an entirely new operating environ- ment for business. They pose one of the signi- ficant challenges to senior management today. To cope with these pressures-which we have termed the new public realities-we must deal more effectively with the media, the public, and government. However, before examining methods for improvement, it is essential to understand the nature of these new public realities and par- ticularly their determinants-the underlying eco- nomic, sociological, political, and international events and trends which have shaped them. Previously the productive element of society had only to concern itself with what might be termed `conventional realities' : the costs of labour, equipment, and land, as well as marketing and distribution factors.

Jan 1, 1978

The Southwest Pacific is a region of active volcanism and geothermal systems. Only in New Zealand have the geothermal systems been exploited for electricity generation and industrial processing. At present, approximately 280 MWe of geothermal electricity is generated in New Zealand. A considerable amount of further exploration work is required before the total geothermal potential of the region can be assessed and before the significance of these resources can be judged against other local energy sources.

Jan 1, 1990

The Permian coal in the Muja Coal Measures of Collie Basin of Western Australia has a subdued lustre because of the fine laminations of lithotypes, and the dominance of dull and dull banded lithotypes with minor bright, bright banded and fusinous types. The maceral composition of the coal is variable, however the macerals of vitrinite and inertinite groups dominate and the exinite and mineral matter contents are low. The lithotypes have low concentrations of trace elements and the boron concentration is between 10 - 100 ppm recorded only from the dull lithotypes. On the basis of organic petrology, the inter-seam sediments, flora and the very low concentration of boron, the depositional environment postulated for the coal is braided, fluvial and fluvio-lacustrine with marked fluctuations in the water table. The low water table in the environment accounts for fusain and inertodetrinite in the coal.

Jan 1, 1996

The traditional concept of optimum drill and blast is that it is achieved when ore is produced at the lowest unit cost and, because of the complexities of most mining operations, represents a band which extends either side of an overall cost m

Jan 1, 1998

Recent geological mapping has indicated changes to the stratigraphy of the Pine Creek Geosyncline. The new stratigraphy and interpreted depositional environments are examined in relation to the distribution and genesis of stratabound mineral deposits. Basinward correlations are made with near-shore carbonate and psammite-rudite units in the Rum Jungle region. Most other units in the same region are condensed, indicating long- lived supratidal, intertidal or shallow conditions during most of the depositional cycle. Units containing most of the mineralisation represent the earliest near-shore developments of strongly reducing partly pelitic and evaporitic conditions and contain mainly uranium and base metals. Restricted distal, strongly reducing facies with associated felsic volcanics are also well mineralised, and mainly contain gold, silver and base metals, although some deposits are probably genetically related to synorogenic or postorogenic granites. Mineralisation in other facies is almost all epigenetic hydrothermal in origin, although minor mineralisation is related to volcanics, or dolomitic parts of the sequence. Areas of potential mineralisation include near-shore environments in the north, and carbonate reefs along growth faults. Two suites of postorogenic felsic volcanics and related sediments deposited in shallow water within and around northwest and east-northeast rift systems, overlie the metasediments of the Pine Creek Geosyncline in the south. The suites have potential for volcanogenic deposits, mostly of uranium, gold and copper.

Jan 1, 1984

The Savage River open cut magnetite mine is located in rugged terrain in densely rain forested northwest Tasmania. The mine and concentrating plant are both in the Savage River valley. Pickand Mather Incorporated (PMI) operated Savage River as an open cut magnetite mine between 1966 and 1996. Acid rock drainage (ARD) was first noted in the last ten years of the operation, leading to elevated concentrations of heavy metals downstream of the mine. When operations ceased in 1996, PMI returned the mine to the Tasmanian Government along with a remediation fund of $11.4 million. At that time, the assessed cost of remediation was in excess of $120 million. As a result of the ongoing ARD contamination and to facilitate both a new operation and effective remediation, Goldamere Pty Ltd negotiated an agreement with the Tasmanian Government in 1996, which resulted in the Goldamere Act and the Goldamere Agreement. The agreement has allowed Australian Bulk Minerals (ABM) to remediate the Savage River mine in conjunction with the Tasmanian Government while re-invigorating a previously closed mine by providing ABM with an indemnity against past pollution. ABM can configure its mine and waste planning activities to maximise remediation benefits without fear of future litigation for past mistakes. The effect to date has been the development of a long-term strategy to remediate the Savage River and short-term remediation works such as water management, which provide benefits to the ecosystem. After five years, the Savage River is no longer significantly impacted by ARD for 30 kilometres downstream and trout are now reported within the reaches of the mining lease. The arrangements between ABM and the Tasmanian Government are an example of a genuine WIN WIN situation where co-operative environmental management of the site results in significant improvements and where the æregulatorÆ and the æminerÆ are working together to achieve mutually beneficial goals. The end result is a significant benefit to Tasmania.

Jan 1, 2003

By S N CARRAS

Ore reserve estimation is a procedure involving data collection, data storage and judgement and assumptions about geology mining and metallurgy. Calculations are based on these assumptions and an economic analysis on projected cash flows is carried out. Ore reserve estimation must therefore be subjective and will always depend on the extent to which the assumptions used in arriving at the estimate are correct. This paper is an attempt to summarise the many aspects that can contribute to ore reserve problems and to offer some suggestions on how to minimise these problems. For further details on specific concepts readers are referred to the detailed descriptions in the referenced papers.

Jan 1, 1992

By M Cooksey, Z Zhu, N Langrené, W Chen, T Tarnopolskaya

"Dynamic decision-making can significantly increase the value of mining projects and deliver better sustainability outcomes under conditions of uncertainty. Despite its benefits, dynamic decision-making is rarely used by the mining industry, possibly because of the complexity of the algorithms used to make sequential decisions under uncertainty and difficulties in visualising the optimal strategies. To achieve better outcomes in practice, decision-makers in industry would benefit from a tool that would help them to understand and implement the results of the analysis.CSIRO is developing innovative dynamic decision support tools that include an intuitive graphical display of the boundaries between the regions of different optimal decisions, which would significantly assist optimal sequential decision-making under uncertainty. The dynamic decision support tool is based on novel stochastic optimal control methodologies that can be used to optimise decisions in situations with multiple uncertain variables and decisions (Tarnopolskaya, Chen and Bao, 2015; Chen et al, 2015; Langrené et al, 2015). The types of market uncertainties that can be considered include commodity prices, interest rates and exchange rate, while the key orebody uncertainties include the reserves, boundaries between ore types and even geometallurgical parameters.The dynamic decision support tools have a number of benefits and can be used to:construct optimal operational strategies and to optimally manage resources projectsgain insight into optimal strategies under different market conditions and project settings compare expected project values under different project settings and to select the setting that provides best sustainability outcomes.This extended abstract demonstrates the use and benefits of the dynamic decision support tools using a synthetic case study of a gold mine.CITATION:Chen, W, Langrené, N, Tarnopolskaya, T, Zhu, Z and Cooksey, M, 2016. Dynamic decisions under uncertainty – a case study on a gold mine, in Proceedings Life-of-Mine 2016 Conference, pp 20–23 (The Australasian Institute of Mining and Metallurgy: Melbourne)."

Jun 28, 2016

By Linying W

Entropy is an important concept both in natural and social sciences.Considering the preparatory process of the earthquakes as an open system, in view of basic ideas of the Theory of the Dissipative Structure, the seis-mological Entropy is introduced as an order parame-ter, describing the scale of order associated with the earthquake distribution in time, space and mag-nitude. The features of evolution of seismic acti-vities before and after the large earthquakes have been studied by using the seismological entropy.The preliminary results show that the seismological entropy in certain region decreases as the large earthquake is approaching, it means that the distri-bution of earthquakes has turned gradually in order from disorder.It is expectation that the application of the Principle of Entropy in seismological research will deepen the understanding of the physical process of earthquake preparation. Meanwhile, it will also offer some enlightements in studying mitigation of seismic hazard as well as earthquake prediction.

Jan 1, 1990

By A S. Kurilko

For mines located in the cryolitic zone, thermal conditions are an important factor for all kinds of mining works, especially for ventilation of workings. In the present paper, some models of mine air heat transfer considering air distribution in a net of mine workings are developed. A combined solution is suggested for heat transfer and air distribution problems in mine workings and other underground structures located in the cryolitic zone. A software package is also presented for calculating temperature conditions in an underground refrigeration plant and for optimisation of ventilation conditions. This software uses a special 3D mathematical model to describe heat transfer in a freezing chamber between surrounding rock massif and stored product as well as between atmospheric air and the daylight surface of rock massif. A problem requiring strengthening of a backfill material and its thermal interaction with surrounding rocks during underground deposit mining by horizontal layers in conditions of the cryolitic zone is also discussed. The developed program takes into account cement consumption, geometrical dimensions of workings filled and a sequence of deposit mining.

Jan 1, 2005

By C Antonio, R Narayan, A Scheuermann, S Quintero, M Edraki, M Ziemski

Tailings are mostly loose material and can be classed as non-plastic sandy silts. They also tend to have low permeability, resulting in slow consolidation (settling) rates and low shear strength, even after consolidation. These qualities make them prone to liquefaction and, therefore, physical instability. In contrast, coarse waste rocks possess high shear strength and permeability when stacked in dumps. However, air and water flow-through the voids can cause acid mine drainage (AMD) with significant undesirable environmental implications. Combining the two waste streams before disposal by mixing presents a potential opportunity to harness the desirable properties of both waste streams. This practice is termed co-mingling and is prevalent within the coal processing industry. Co-mingling of metalliferous mine tailings is, however, a relatively new concept. By combining the coarse waste rocks and fine-grained tailings streams, the fine tailings tend to fill the voids between the waste rocks, reducing hydraulic conductivity and advective air (oxygen) flow into the rocks, thus possibly reducing acid mine drainage (AMD). Conversely, tailings are introduced to large frictional particles from waste rocks, providing reinforcement, stability, and possibly improved drainage. New separation methods are being introduced to the mining sector, which have the capacity to extract waste with significantly larger particle sizes. High Voltage Pulse (HVP) is a technology in which relatively coarse particles ranging in size from 30 to 100 mm are exposed to an electric pulse discharge. This pulse preferentially fractures mineralised particles while leaving unmineralised rock (gangue) intact. The stream can then be passed via a screen, with smaller mineralised particles reporting to the undersize and removing coarser unbroken barren particles, thereby eliminating waste. Coarse particle flotation (CPF) is another emerging new technology in metalliferous mining that applies flotation separation to coarser particles than conventional flotation. These new technologies produce different tailings (waste) streams with varying physical characteristics and possibly surface chemistries. This research aims to test new tailings mixtures by applying the co-mingling concept to blend the reject streams generated by these two technologies (HVP and CPF) with the tailings produced by conventional flotation. Combining different waste streams before disposal can improve stability and potentially reduce the acid mine drainage (AMD) rate, thus enabling early access to the tailings storage facility for rehabilitation and closure.

Aug 2, 2023

By Lunardi P, Pelizza S

The link between the Lecco bypass and major road SS36 (Italy) requires the construction of a double two-way tunnel (through the mount San Martino carbonatic massif). The tunnel excavating section is about 90 sqm through mount San Martino carbonatic rocks. The mountain sides are unstable and are often the scene of large collapsing landslides (tens of thousand cubic metres). The tunnels are very close to the mountain sides. The use of blasting induces vibrations which may reach the Lecco built-up area. With a view to avoiding such dangers the excavating operations were carried out in two successive stages: - opening a pilot tunnel, whose section is about 10 square metres, by a full face TBM to eliminate the more intense vibrations which are generated by the first opening charges; - successive enlargement by blasting.

Jan 1, 1987

By Kabel J. G

While a per onnel location system is primarily used to check that nobody is left in the mine at firing time, it is also useful for contacting people, uch a foremen, shiftbosses and tradesmen, who travel over several mine levels during a shift. The system installed at The Zinc Corporation, Limited, Broken Hill, uses punched coded plastic identity tags, with "In" and "Out" tag readers on each level. When entering a level, the employee inserts his tag in the "In" reader, and when leaving, in the "Out" reader. Each reader is connected to a central computer which shows who is still in the mine and their location.The system has been used on 3 levels by 21 men for a trial period of 4 months. It ha proved reliable in an underground mining environment, and employee acceptance has been good.

Jan 1, 1984

By B P. Banerjee, D Patra, S Raval

Roof bolts are an essential component of roof support systems in underground mines. They are used to provide structural support to the roof of the mine and prevent it from collapsing. Therefore, it is imperative to perform regular assessments of these roof bolts to avert any hazards. Manual investigations of roof bolts are done by surveyors in underground mines, which is extremely timeconsuming and challenging due to the low-light conditions in underground mines accompanied by stringent mine access rules. To this end, automated recognition of roof bolts in 3D point cloud data obtained through laser scanning in underground mines serves as a potential solution to aid roof bolt monitoring. With the continuous advancements in laser scanning-based 3D data acquisition systems, the feasibility of making such surface estimations from 3D point cloud data has increased severalfold.

Sep 1, 2024

By Sillet R, Corin P. J, Wilson G

Zinc Corporation of Broken Hi11 had some long hole stopes coming into use which could not be mined using diesel loaders, because of ventilation restrictions. In preference to use of pneumatic loaders, and because there were no field proven electric loaders in Australia, Horwood Bagshaw Ltd., were commissioned to repower a diesel loader with an electric motor, within the confines of the existing machine

Jan 1, 1977

An image analysis system has been built which automatically digitizes camera input of rock fragments, analyses the digitised data to determine the sizes and shapes of the rock fragments, and outputs the analysed data to a printer in the form of a histogram or a scatter chart. The high speed of such a system allows for direct collection of data from material thrown into the air by blasting, material travelling on a conveyor belt, and material free-falling on to a stock-pile or into or out of a rock-crusher. Data on the blasted, un-crushed material provides information on changes in the lithology and structure of the rock face as it is quarried or mined: flatter fragments may represent approach to a brittle, unstable shear zone, or a change from sandstone to shale; so that the informa- tion reflects the effect on the sizes and shapes of the fragments by the blasting process and/or by the rock structure. The size and shape distributions of rock fragments produced during blasting and during processing may now be continuously monitored. Such detailed analysis of the results of fragmentation is labour-intensive and expensive when the size and shape distributions are obtained manually, but is cheap and efficient when using this image analysis system. Such a system will enable the results of blasting, quarrying, mining and crushing to be cheaply analysed and correlated with current and changing indus- trial practice so leading the way to increased productivity.

Jan 1, 1988

The issue of flyrock is critical to the operation of all mineral extraction sites that use blasting. This paper takes a risk-based approach to identifying, analysing and managing the flyrock hazard. The basic cause of flyrock generation is a mismatch between the energy available and the work to be done. It should be noted that the energy available depends on the charge confinement. This mismatch can be caused by an abrupt decrease in rock resistance (geological weaknesses), overcharging, inadequate delays between holes and rows, inappropriate blast design and inaccurate drilling. The mismatch can come about from two sides; either too much energy (charge) for a fixed burden (work to be done), or insufficient burden (work to be done) for a fixed charge. The main mechanisms of flyrock generation are rifling, cratering, face bursting and secondary blasting. Each source mechanism has different characteristics in terms of vulnerable locations and each requires different control measures. However, all controls require a high level of quality control and assurance. A range of different approaches for managing flyrock risk and determining blast clearance zone dimensions are presented. A prescriptive consequence-based approach is discussed. A conventional risk matrix based approach is outlined with some innovation regarding controls rating and uncertainty ratings. A published semi-empirical approach is discussed. Two examples of quantitative flyrock risk analysis are presented; one involves bench blasting based on a published paper and the second is a cratering example developed by the author based on consulting projects. Finally, a stochastic approach based on published work is presented which simulates cratering superimposed on face bursting mechanisms. Also, a stochastic analysis undertaken by the author of the cratering example is presented. Effective blast emission management is required for two reasons; firstly to reduce and/or eliminate safety risks and secondly to manage public perception of blasting risks such as flyrock. The conclusion of the current research is that the wild flyrock risk can be estimated using existing techniques. Furthermore, both qualitative and quantitative risk management methods as discussed in this paper can be used for flyrock management for a given blasting situation. A combination of both is considered to be best practice.

Jan 1, 2007

High sulphur volcanic-hosted hydrothermal environments are favourable geological environments for gold mineralisation. Numerous world-class gold deposits including Pueblo Viejo (Dominican Republic), Goldfield (Nevada), EI Indio (Chile), and Wa

Jan 1, 1994