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By Barnett DW

Financial risk analysis provides the tools to examine the uncertainty of capital decisions in new mining ventures. This paper explores the methodology by which financial risks can be studied and quantified. The most commonly used risk evaluation methods, such as sensitivity analysis and discount rate adjustment, are presented as an introduction to a more comprehensive discussion of stochastic methods of discounted cash flow analysis using Monte Carlo sampling. The discussion is illustrated with examples of a stochastic discounted cash flow. The advantages of Monte Carlo sampling in risk analysis are discussed together with its problems, particularly those originating from the correlation amongst the variables that determine the economic output of a mining venture, and the difficulties created by insufficient data, imperfect knowledge and complexity. The paper also surveys the most commonly used software used in risk analysis.

Jan 1, 1994

The introduction of on-stream analysis in flotation circuits has raised the possibility of automatic control of flotation performance by digital computers. The development of control strategies for an industrial zinc cir- cuit is discussed with reference to identifi- cation of the major disturbances, investigation into the performance of the circuit, the design of the control algorithms, the testing of their performance and their implementation in a production environment.

Jan 1, 1983

By J Meikle

A projected image is not always a true representation of a situation, or indeed an industry. This is often the case of the mining and minerals industry, which has frequently been portrayed in a negative light with a male dominance stigma attached. However, these issues can be combated for both the industry and its future, current undergraduate students, through undergraduate industry experience. In particular, vacation work enables female students to dispel many myths surrounding the industry and realise that the mining and minerals field offers career development for both genders. This paper will discuss how vacation work enables students to make important career decisions even before they have graduated. Industry experience provides undergraduates with the opportunity to gain practical knowledge relevant to their field of study. Additionally it allows students to observe the nature of the industry and the sacrifices necessary to advance careers. The prior insights into an industry are relevant to all students, but particularly female students, who might otherwise be dissuaded from a career in mining. This paper is written from the perspective of two female undergraduate students studying Mining and Minerals Processing Engineering.

Jan 1, 2006

Geotechnical practice combines the site engineering geological model with engineering design and operations to control risk. The responsibility of the geotechnical professional is to present relevant engineering geological information to an engineer to effectively impact an outcome. Return is enhanced by understanding expected operating and capital cost due to ground conditions.   Risk is effectively communicated by a successful geotechnical practitioner. In a mining environment the need is to assess ground conditions accurately and quickly, and to effectively communicate expected ground response due to mining. A good engineering geological model includes a description of geotechnical engineering parameters to design assuming reasonable expected soil, rock and water conditions. Pit slopes are steepened, stope spans widened and waste foundations and land forms are constructed all under geotechnical control.   The responsibility of the geotechnical professional is to collect, assess and disseminate relative engineering geological information. The geotechnical professional is a person advising on ground related engineering, and generally operates within geology and engineering end members.   Return is better assessed on an understanding of ground cost. In operations the goal is to meet production at lower cost. In evaluation, regional and exploration geology, mine design and expected operational factors influence expected cost and project return. Return allows companies to meet shareholder expectations, attract equity to develop and add value to the community.   This paper presents a discussion with some examples to present an approach and design philosophy for geotechnical practice in the mining industry.

Jan 1, 2004

The role and policies of the Aboriginal Sacred Sites Protection Authority are described in conjunction with the provisions of the N.T Aboriginal Sacred Sites Act 1978. Comment is made on the application of the legislation and these policies to development proposals in the Northern Territory. A brief review of criticisms by both developers and Land Councils is provided together with responses to these Criticisms.

Jan 1, 1984

By G Lane, S Morrell

The design of the 12 m diameter SAG mill installed at the Cadia Hill Mine in New South Wales followed after two years of extensive laboratory and pilot plant testwork. The testwork showed the Cadia ores to be hard and competent necessitating the use of both a variable speed SAG mill drive and pebble crushing. The grinding power requirements for the SAG mill was based on engineering in-house grinding software, pilot plant data and simulations using JK SimMet software. Surveys of the SAG mill operation during the first four weeks showed the feed size distribution, transfer size and pebble rate to be lower or less than those for which it was designed. To compensate for the lower pebble rate, the SAG ball load was increased. This resulted in the total comminution circuit power being some 0.5 kWh/t higher than predicted. The JK SimMet SAG model has been modified to take account of these variations.

Jan 1, 2000

By Hosking IA, Mirkov P

Among the solutions currently being considered for improving traffic flow in Sydney are the construction of major road tunnels, principally the Eastern Distributor Tunnels, leading from the end of the Cahill Expressway to Drivers Triangle and South of Taylor Square and the Sydney Harbour Tunnel, which incorporates sections of driven tunnel at the northern and southern sides of the harbour. The Eastern Distributor Tunnels, known as Stages 2 and 3 of the Eastern Distributor Scheme comprise: Stage 2 - A south bound two lane tunnel from north of William Street to Driver's Triangle. The southern end includes two Y junctions (locally 3 to 4 lane widths) with exits into South Dowling Street, Anzac Parade and Moore Park Road. Stage 3 - A north bound, two lane tunnel from Taylor Square to Palmer Street just north of William Street. Further details of the Eastern Distributor Tunnels are given in the paper by Baxter, Chappel and Fishburn (1986) which is included in this conference.

Jan 1, 1987

By Ichinose M, Tsuru T, Gotoh K

Since 1980, the Department of Mining Engineering at Kyushu University, in co-operation with the Ikeshima Colliery, Matsushima Coal Mining Co. Ltd., has been conducting a research project into longwall gateroad designs applicable to deep and poor strata conditions. During this period, the economic environment has drastically changed the situation of the domestic coal mining industry. Conventionally, the retreat longwall method, with re-use of gateroad, has been employed as it achieves higher recovery. However, from the view point of production efficiency, this method is not suitable because it requires intensive work in side packing and roadway maintenance. Therefore an interpanel-pillar system, or a two-entry gateroad system, was adopted to identify the factors responsible for excessive vertical closure in longwall gateroads. Field measurements and non-linear finite element analyses were undertaken to confirm the performance of this system. Study results indicate that the stability of the gateroad employing the rib pillar system is comparable to that of the conventional system of re-using Gateroads.

Jan 1, 1992

The problem of stability of the development working at the great depths of coal winning is of great seriousness. Numerous researches of the problem were carried out in the USSR, the results of which determined that raising of resistance of existing support will not lead to a considerable rise of working output. It is necessary to try to find ways at the expense of heightening the support ability of rock massif. For these purposes it is necessary to direct it correctly and in proper time. While carrying the development working the most intensive deformations of rock occur at a depth of 30m from the entry face. The zone of destruction of rock around the work is realised here for 60 to 70 percent. These facts show that in influence zone of entry face a kind of embryo of the working steadiness is forming, which greatly determines its following conditions. Therefore, it is necessary to begin direction of mining pressure around the work directly in a face.Complex research of the mechanism was carried out starting with the effect of moving face upon the surrounding rock massif. It was ascertained, that the zone influenced by the face is a section of 5 equivalent diameters of the work by the length within which the rock of the sides, roof and floor, experience the cyclical influence of stresses at the time of cyclical shift of the face. The elastoplastec deformation is occurring with it at the moments of rock removal and the deformation of creeping takes place at such intervals.

Jan 1, 1991

Downstream value-adding is a strategic issue for a country like Australia, which has a resources-driven sector of a scale that has significant impact on the national economy. The question of why producers are not doing more to ævalue-addÆ is often asked. In Australia this debate takes place within the context of: an era of unprecedented growth in demand for resources driven by the rapid urbanisation of China, India and others;impending legislation and uncertainty around carbon pricing;rapidly rising energy costs;significant supply-side shortages including infrastructure, skills and manufacturing capacity; andsignificant industry consolidation of primary resource producers with commensurate improvements in market power.There are several examples of resource-based industries which have developed their business along the complete value-chain; for example large oil and gas producers successfully span upstream and downstream operations including refining and petro-chemicals as well as retail distribution of fuel and other products. Relevant frameworks that provide insight and understanding into the strategic issues around value-adding are reviewed and examples of the application of these frameworks to companies and industries which have successfully adopted a strategy of integrating along the value-chain, as well as those players who have focused on parts of the value-chain are presented. The issues around value-adding in Australia are then reviewed with reference to these frameworks and it is concluded that the issue is a conflict between the objective companies who wish to maximise financial value versus the desire of governments to increase economic benefits. An approach to aligning these objectives is proposed.

Jan 1, 2008

The major heavy industrial consumers of limestone are the cement, lime'and steel ind- ustries. Each of these requires large quantities of cheap raw material. Other ind- ustries such as glass and chemical manufactur- ing are significant consumers and agricultur- al and constructional activities provide additional demand which is usually more local in its occurrence. Limestone is widely dis- tributed throughout Australia but location in relation to major markets, and transport con- siderations render most deposits of no economic value. Among deposits which are sufficiently close to the major metropolitan markets many must be rejected as being unsuitable on grounds of quality, inadequate size for major.develop- ment, or other reasons such as environmental considerations. The major producing locations are sit- uated in a variety of geological environments. Most have limited reserves and require partic- ular attention to quality control. Planned extraction programmes based on detailed geo- logical investigations enable not only satis- factory grade control but also permit, by the adoption of appropriate quarry procedures, the use of sub-grade material, thus optimis- ing utilisation of the available reserves.

Jan 1, 1976

By S Pollak, A Amon

This paper describes the current and finished design work which has been performed for shallow rock station caverns for New York CityÆs first new subway construction in 60 years. A new robust, sophisticated, design procedure has been developed for two up to 30 m wide caverns, with overburden of less then 12 m, and rock cover to span ratios (C/S) in the order of 0.25. The design is based on empirical input parameters like the Q-value, rock mass rating (RMR) values, rock mass class after Cording (1984), cover to span ratios, which have been validated by the use of structural computer models as well as two- and three-dimensional numerical discontinuum models. The design approach is a staged approach using first principles, empirical models and non-linear FEM and DEM models. In addition, the paper describes the factors and circumstances why shallow caverns have been selected instead of cut-and-cover structures and why all the underground station structures have been developed as drained structures.

Jan 1, 2008

The environmental and social responsibilities of the mining industry have long been recognized by the industry itself, but during the past decade it became one of the main targets for the more radical members of the community. This came as something of a shock to an industry which had always considered that it had acted responsibly within the standards of the day. As far back as early 1968, the Australian Min- ing Industry Council (AMIC) was clipping from newspapers the odd letter written by environmen- talists and critics of mining activities. In those days every such letter was carefully studied to ensure that AMIC, if not having the answers, at least had an understanding of the types of argu- ments then starting to be used against mining activity and in favour of environmental preserva- tion. Within 18 months, the infrequent letter to the editor had become a flood of such letters and feature articles, and the environmentalists' attack on mining activities had been launched in all its Vehemence.

Jan 1, 1978

The Circum-Pacific is defined to include back arcs and continental areas of volcanism. Volcanoes must be regarded as dormant, if the time since their last eruption is less than about ten times the average interval between eruptions, even if they have not erupted for tens of thousands of years or longer. It is important to establish a complete history, over as long a period as possible, for varying volumes of eruptions. In order to assess risk, the average interval between eruptions should be calculated for each range of erupted vo4ume~, in orders of magnitude from about 10 m up to the maximum volume possible at each volcano. Eruptions are considered to consist of individual explosions, and are grouped into eruptive sequences, with the sequences grouped into overall cycles of activity. Frequency of eruption versus volume erupted is a linear relationship for most andesitic and basaltic volcanoes, but is often bimodal at rhyolitic volcanoes, 3 with a slower eruption rate above about 10 km. Worldwide, during the last 7000 years, there have been three known e~uptions with volumes of ejecta of > 100 km , a9d, since 1638 A.D., 7 with volumes > 10 km , and 48 with volumes > 1 km . Average recurrence intervals are about 71 years for eruptions of > 20 km , 39 years for those of > 10 km , and 7 years for those of > 1 km . Rough esti- mates can be made for larger volumes erupted. Mean intervals in the Circum-Pacific are about twice the length of those for the world as a whole. During the last 400 years, about 61% of the world's eruptions of > 1 km3 have taken place in this region.

Jan 1, 1987

Offshore petroleum development involves massive capital expenditure and financing demands, with the main participants being large international oil companies and State owned enterprises. Types of project oriented financing include take-or-pay contracts, throughput agreements, and production payment financing. The main project finance credit aspects are revenues, investment budgets and cost over- runs, reservoir, political and other risks and special problems such as weather and corrosion in the North Sea. A variety of documents is required and a mix of equity, export credit and Euro-market financing will typically be included in the financing.

Jan 1, 1983

For the purpose of this paper the Otago Region is that covered by the Otago Regional Council. This area, like other South Island Regions, has a river system starting in the Mountains and are all gravel bed rivers. The gravel from these rivers has been the major source of aggregate in the region since the development of the province began. The majority of the aggregate is a mix of greywacke, schist and quartz, which will be referred to later with its production problems. The region has been broken down into various areas.

Jan 1, 1992

The paper describes the progress made in the last decade with the introduction of comprehensive monitoring of the mine atmosphere into U.K. collieries. Brief descriptions are given of the various portable and fixed point instruments which have been developed for this purpose and the methods available for transmission of information to the surface are also discussed. The paper also outlines some of the research work being carried out both in the laboratory and underground on the development of alternative methods of fire detection. Some of the results from this work are illustrated and discussed.

Jan 1, 1981

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

By A Roseman, T Gruber

Traditional methods for installing gaskets for segmented bored tunnels have relied upon different bonding procedures with adhesives that carry a series of disadvantages to segment producers. Fixation of the gaskets into the concrete segment as part of the casting procedure has been developed over the last 20 years and has emerged as an economical solution to produce high-quality tunnel segments for various technical tunnel applications. This paper investigates the advantages of using anchored gaskets, the different tunnel systems that employ anchor gaskets and reviews the first anchor gasket project; the Lee Tunnel and analyses how segment production efficiencies are gained.CITATION:Gruber, T and Roseman, A, 2014. Use of anchored gaskets in segmented bored tunnels, in Proceedings 15th Australasian Tunnelling Conference 2014 , pp 253–256 (The Australasian Institute of Mining and Metallurgy: Melbourne).

Sep 17, 2014

Not so many years ago the reason for an inadequate result from a geophysical survey was insufficient data or poor quality data. In many instances such as gravity, magnetic and radiometric surveys, both these constraints are vanishing or have vanished. High quality sensors, improved data storage, accurate differential GPS and top quality interpretive software now enable the interpreter to understand not just the cause of the anomaly but the host environment in which it resides. Examples of potential field data and also data provided by the more complex electromagnetic systems, from Australia Ghana, West Africa, are used as illustrations.

Jan 1, 1997