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By Inoue T, Takahashi N

To construct the accessing railroad line to the northern portal of Seikan Undersea Tunnel, nine tunnels amounting 7.4km in their total length were excavated through soft mudstones of young- er tertiary era with use of smaller-sized mechanic al excavators. Rocks were classified in four classes to which the tunnel support was designed respectively. Of several combinations of driving equipments stu- died comparatively, the method using the mechani- cal excavators was estimated to be the best choi- ce. The efficiency of the excavator was traced in every construction section and the data colle- cted was reviewed numerically. The result showed that the efficiency of the excavator dropped wh- ere the rocks were as hard as over 200kg/crif for compressive strength. And a few technigues in tunnelling i.e. contr- olling dusts in shotcreting, lattice arch, evaluati- ng measured deformations were tested and review- ed too.

Jan 1, 1987

Human creativity springs from the natural desire of mankind to know and its capability to learn. Explorers and discoverers possess these features in a high degree. They are driven by an unrelenting curiosity to go beyond the boundaries of the known, to explore into the nature of things, to reveal connections between ideas, facts, conceptions, to view things from new angles, to change perceptions. A well-known fact about the construction industry - and underground construction in particular - is that all projects are unique. The degree of complexity due to the intertwining of the variety of project-related parameters is higher than in many other industries, thus forcing contractors as well as suppliers to be truly adaptable and flexible. The enormous advantages of shotcrete as a construction and rock support process and the improvement of materials, equipment and application know-how have made it a very important and necessary tool for modern underground construction works. The development of modem wet shotcreting in particular has enlarged the field of underground construction work. Projects that were impossible to be realised, have now become practicable. Subsurface structures can be placed where they are needed, without regards as to rock and soil conditions.

Jan 1, 1995

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

It is well known that in most areas of Central Europe it is not difficult to find water - usually at shallow depths - and to recover and use this water. What is much more difficult, however, is to find water sources that offer both sufficient in quantity and qual- ity. Far too often, there are sources that offer abundant quantities but of poor quality or vice versa, i.e. high quality water but insufficient volumes. In the former case where water quality is not adequate - which is more often than not due to anthropogenic factors and only very rarely a result of geogenic effects - the application of treatment techniques can help to turn such water into potable water that is suitable for human con sumption.

Jan 1, 1988

By Ö Aydan

Rock dynamics is one of the most important topics in the field of rock mechanics and rock engineering. The spectrum of rock dynamics is very wide and it includes the failure of rocks, rock masses and rock engineering structures such as rock bursting, spalling, popping, collapse, toppling, sliding, blasting, non-destructive testing, geophysical explorations, science and engineering of rocks, earthquakes, and impacts. Undoubtedly, the rock dynamics issues in Mars would remain to be the same. Although mankind has no direct access to Mars yet, the Mars exploration rovers (Opportunity, Sprit, Curiosity and Perseverance), Mars Reconnaissance Orbiter and InSight Lander provided very valuable data so that some rock dynamics issues can be recognised. The author reports his considerations on rock dynamics issues in Mars from very careful examination of images and data provided from MERs and MRO and discusses their implications.

Nov 29, 2022

By M F. Lee

In order to make good decisions, as to whether large diameter raise bored shafts can be constructed in blocky rock at a particular location, mine planners, management, geotechnical engineers and contractors must understand and consider a range of geotechnical issues. Firstly, mine management must ensure that adequate time and resources are available to find appropriate shaft sites. Deep weathering, adverse structures, groundwater, etc might mean that the most desirable location, with respect to other mine development, might not be suitable. Special site investigation drilling, etc may be necessary. Even then, alternative construction options might be necessary, other than just reaming through to the surface. A site investigation borehole should then be drilled to investigate specific and general ground conditions along the raise alignment. Often, only small sections of weak blocky rock dictate raise stability. While the empirical McCracken and Stacey method is typically used in Australia to assess raise stability and assess geotechnical risk, until recently it had no published performance data.An Australian database of raise performance now exists and is presented below, courtesy of an industry survey by the Eastern Australian Ground Control Group. Raise diameter and ground conditions (in terms of a lower bound Qr value) is presented for 50 cases versus raise performance.

Jan 1, 2008

The interaction of man with the environment has a double character. From one side, mankind can not exist without co- nsuming the natural resources and, from the other side, we actively alter and exert influence upon nature. Analysis reveals that the ecological problem is, to a great extent, a geological one. The paper deals with the application of grouting techniques to construct impermeable barriers for the protection of ground water and soils from depletion and industrial wastes pollution. A number of case histories in the field of mine construction is given to illustrate the solution of geotechnical problems in concert with environ- mental protection measures.

Jan 1, 1988

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 development of paraprofessional courses in metallurgy and related disciplines, by the Department of Technical and Further Education in New South Wales, is outlined in this paper. The changing nature of metall- urgical educational requirements is summarised, and various attendance patterns discussed. The potential advantages of the sandwich system of College attendance, to the more distant sectors of the mineral processing and metallurgical industry is outlined. Some of the likely future trends in technician education are presented. These include the need to respond to the changing expectations of technician employers, as shown by industrial surveys, the role of experiential learning, the need to integrate courses so that students can build on prev- iously completed courses, the possibility that future technicians will require a multi- disciplinary background and the provision of easier access to technical college facilities by potential students and industries.

Jan 1, 1978

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 R S. Suglo, G-K Er

Mineral processing is an essential component of a mine production chain and it accounts for significant proportion of the production cost. Over the past decade, significant research progress has been made in processing plant efficiency using theoretical, experimental and simulation modelling techniques. However, these studies are limited to process plant system as stand-alone units with no interactions with the mining units. In order to maximise the total mining system efficiency and more accurately simulate the system, the processing plant must be modelled as part of an integrated mining system. This becomes increasingly important in continuous surface mining systems, with limited ore processing capacity. In addition, plant efficiency is roughly estimated with known parameters or with simplistic statistical data, without regards to the stochastic processes governing these parameters, such as processing plant feed introduction. In this paper, a comprehensive model of the ore processing plant system is given and the object-oriented design (OOD) of the system is briefly introduced. The joint operation of ore processing plant system and haulage system is analysed. Numerical modelling is used to analyse the ore processing plant system under different conditions. Analysis of the results show that the optimum plant capacity is 0.7 tons/sec (2520 tons/hour). The results also show that the plant system resources cannot be fully utilised because the production rate is always less than the plant capacity. When plant capacity reaches an optimum value 0.7 tons/sec, the production rate is about 0.64 tons/sec. The underlying stochastic processes associated with plant and mine capacities cause this variability. In order to reduce this variability, there is the need to tightly set tolerances for the function variables.

Jan 1, 2003

The word governing derives from gubernare meaningto pilot a ship. Being inclined to metaphors, one could be forgiven to think that politicians act this verb and captain the Nation's ship into some definite course. In the case of at least the mineral resources industry, it seems that there are not many James Cook followers in our parliaments: Australia's approach to mineral and energy policy is often chaotic - witness the 1935 to 1961 ban on iron ore export-ing which prevented the development of a significant steel industry at time when the World was hungry for this metal, just to mention one amongst many other examples.The follies of Australia's mineral policies are well il-lustrated in the case of uranium mining. Although Australia had the Western World's largest economic reserves of uranium, it is onlythefifth producing nation and its uranium potential is largely unrealised. At the root of this situation are the interventionist attitudes and policies of successive Federal Governments which for more than four decades distorted the Investment decision and, in more recent times. discouraaed investment.

Jan 1, 1990

By J E. Eberhardt

Ore sorting has long been used to raise the efficiency and thus lower the environmental impact of mineral processing operations. It was first instituted as hand sorting, according to a humanly perceived difference in the ore, but is now automated using large mechanical sorters in order to meet the high tonnage throughput required in most minerals processing applications. In the past, ore sorting was generally used as a niche processing route when other approaches failed, and in this context, consequential environmental benefits are often not the first consideration in adopting sorting. When applicable, ore sorting offers environmental benefits in reductions in fines waste, reagent usage and energy consumption in milling. Although there are significant opportunities for the use of ore sorting technology in many minerals processing operations, industry applications, to date, have been limited mainly to the processing of diamonds, magnesite, talc and uranium ores. This limitation has principally been due to a lack of suitable sensing technologies for a wide range of ore types. The authors report on a wide-ranging review of the automated sorting of mineral ores, and in particular, on methods for discrimination of ore characteristics prior to mechanical sorting.

Jan 1, 2002

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

The operators of the iron ore railroads in the Pilbara faced problems of excessive wear between rail and wheels as the tonnage hauled increased in the early 1970's. Joint research projects were begun between Hamersley Iron, Mt Newman Mining and the BHP Melbourne Research Laboratories to study these problems and recommend solutions. The particular problems of wheel rail interaction were solved by asymmetrical profile grinding of the rail and modifications to the machining of the wheels. Rail materials were improved through increasing yield strengths by alloying and by heat treatment. Wheel materials were improved by alloying. The economic benefits of these improvements have been demonstrated by much reduced re-rail requirements and other reduced maintenance costs.

Jan 1, 1986

This paper comprises a discussion of standards for comparing conditions in mines, of methods for measuring the flow of air, of a comparison of fan performances, and the application of these matters to mines in Western Australia.UNDERGROUND CONDITIONSIn approaching the question of mine ventilation one naturally searches for some standard by which to measure the conditions in a mine.There are several clauses in the Mines Regulation Act defining the conditions which are permitted. The quantity of CO2 is limited to 0·25 by volume, but the estimation of CO2 involves a chemical determination and is not suited for general use in a mine.The maximum temperature is fixed at 87 0 F. (dry bulb), and at 80° (wet bulb). The reading of temperature is easily done in the working places, and this is a very valuable and practical test of the conditions in a mine.The wet bulb temperature is probably the most important factor in determining working conditions. It is obvious that human life cannot be sustained for any appreciable period if the wet bulb temperature is above blood heat (about 97°F.). In places where the wet bulb temperature is 90°F. there is danger of heat stroke.In places where the air in a mine is still, the wet bulb temperature rises to a value close to the rock temperature.Adequate ventilation cools the workings by transference of heat from the rock to the air stream, and the temperature...

Jan 1, 1939

Over the past several years, copper prices have surged from under a dollar to over three dollars a pound. However, the long-run trend in real copper prices since at least the early 1970s has been sharply downward. While many now contend that the long-run trend in real copper prices is now upward, the result of structural changes in this market, others are sceptical. Nor is copper unique; the prices for a number of other metals, including aluminium, iron ore, lead, nickel and zinc, have followed similar patterns. This paper examines the forces behind short-run and long-run trends in metal prices. It first focuses on the short run, where it argues that shifts in demand are largely behind changes in prices. It then turns to the long run, where it concludes that production costs and supply largely govern price trends. Finally, it explores several implications of these findings, including those for diversification and market risk, for forecasting mineral prices, for assessing the growth of metal demand in China and elsewhere on metal prices, and for changes in the long-run price trends.

Jan 1, 2006

The BHP Steel Group embarked on a Total Quality Control (TQC) programme in 1984 in response to enquiries from a major customer regarding procedures for quality in materials supply.The TQC initiative has been adopted by all seven Divisions of the Steel Group and covers a broad and comprehensive range of management and workforce improvement initiatives.The development of the TQC initiative in the Collieries Division of BHP Steel over the past eighteen months has resulted in important experiences and leanings.

Jan 1, 1991

By J Szymanski, Y Hu

Excavation engineering involves complex processes for primary and secondary extraction of materials. The shovel excavators bear varying mechanical energy input and stress loading across the working bench during excavation. These varying mechanical energy input and stress loading effects cause significant wear and tear and fatigue failure in equipment components. These effects further result in unplanned downtimes, reduced efficiency and high production costs. In addition, the mechanical and electrical control systems must be operated in efficient profiles to generate maximum outputs and efficiency from these excavators. Efficient technologies are therefore required to solve these problems in order to reduce production costs and increase efficiency. In this paper, the authors develop a rigorous simulator for a hydraulic shovel in a surface mining environment. The finite element model is used to capture the stress profile within the shovel components during excavation, such as, the bucket, stick and boom assemblies. The profiles are classified into normal, critical and extreme ranges, with appropriate corrective measures to avoid extreme loading conditions. The loading capability of shovel excavators can be examined by assessing its structural strength against all possible maximum loads working on the equipment. The dynamic model is used to define efficient profiles of the critical structural components of hydraulic shovels during digging operation. This assessment is used to locate the maximum possible loads and the critical sections of the structures. The method presented in this paper forms the basis for developing comprehensive simulator models for efficient shovel operations in constrained mining environments.

Jan 1, 2003