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By Robert Marks, Enrico Dal Negro, Richard Schulkins

"In July 2012 construction started on the Grosvenor project, a five million tonne per annum underground longwall mine planned for Moranbah in Central Queensland. Grosvenor is located immediately to the south of the existing Moranbah North mine which has been in operation since 1998. EPBM technology is being used for the first time in Australia for excavation of a coal drift. The TBM was used to build two drifts on the project, one for the coal conveyor which will transport to surface, and another for people and equipment to access the underground once the mine’s operational (as shown in figure 1). The TBM will pass beneath a steel archway roof that has been installed at the drift’s entrance and begin drilling into the ground to build the seven metre diameter tunnel, descending at an angle of one in eight until it reaches the depth of the coal seam approximately 160 metres below.INTRODUCTION AND BACKGROUND The first TBM used in a coal mine was in 1962, a Wohlmyer, in Westerholt, Germany. A further 75 km of tunnels were excavated in coalmines within Germany between 1971 to 1983. This paper will review the Grosvenor Mine project (Grosvenor) owned by Anglo American Metallurgical Coal (Met Coal) includes the construction of a new underground coal mine and surface facilities on the northern boundary of the town of Moranbah in the Central Queensland Bowen Basin coal precinct. The contract to undertake the underground development works was awarded to Redpath in 2012. The scope of the Grosvenor Project was to construct temporary office and workshop facilities, install 2 portal arches, backfill boxcuts and infrastructure, excavate by EPBM method 967 m of 1:6 gradient Conveyor Drift and 1,258 m of 1:8 gradient Transport Drift, development of 2,520 m of pit bottom area roadways and development of 10,550 m of the first longwall tailgate. In the following figures 2 and 3, is possible to see the aerial view of the job-site."

Jan 1, 2016

By R. C. Gilmore, S. A. Lolon, G. E. Bogin, S. A. Saki, J. F. Brune, J. W. Grubb

"Gob ventilation boreholes (GVBs) are widely used in underground coal mines for longwall gob degasification purposes. GVBs are often drilled within 10 to 30 m above the top of the coal bed into the fractured zone, completed with 20 cm (8 in.) diameter casing and 60 m of slotted pipe at the bottom. The purpose of this completion strategy is to create a pressure sink to capture the emissions before they can enter into the underground workplace. For GVBs to work effectively, they must be drilled close enough to the working areas to capture methane from the fractured zone while the setting depth must be kept above the caved zone to minimize the amount of ventilation air that is drawn into the GVBs. Well completion parameters are important for creating safe working conditions. In this paper, computational fluid dynamics (CFD) studies will be presented to analyze the effect of different practices for GVBs completion parameters for methane extraction, formation of explosive gas zones in the gob and methane concentrations at the longwall face and tailgate. Authors have identified the optimum completion parameters for GVBs, which can maximize the benefit and minimize fire and explosion risk. INTRODUCTION Coal mines may be considered gassy based on the presence of CH4. Gas from the mined coalbed or from rider seams above or below the mined coalbed can migrate into the gob and then potentially move towards the working areas. In longwall coal mines with high methane emissions, sufficient ventilation and additional methane control measures are usually required to reduce the methane concentration in working areas to below statutory levels. Several techniques or combinations of techniques are available to control the methane hazard. These may include mine face ventilation to dilute methane, coal bed degasification, nitrogen injection into the gob to render a methane atmosphere inert and the use of gob ventilation boreholes (GVBs). Longwall face ventilation and dilution alone can only handle methane emissions up to a certain amount. When methane emissions exceed the face ventilation capacity, additional control measures are required. Drilling horizontal or vertical methane drainage holes into the coal seams as well as gob ventilation boreholes from the surface into the gob area to extract methane are common practices. GVBs are usually drilled from the surface above the longwall panel ahead of mining. When the face moves outby the GVBs and the gob begins to form, methane production starts from the boreholes. It is important to control the performance of GVBs to maintain a safe working environment in the mine. The performance of GVBs depends on multiple factors, including borehole location, length and diameter of slotted casing, setting depth of casing above the coal seam being mined, wellhead vacuum pressure, and permeability of caved-fractured zones."

Jan 1, 2016

By E. W. Hawk

he power generation industry may be required to reduce carbon dioxide (C02) emissions if regulations related to global climate change are enacted. Coal-fired generation emits more than 80% of the power sector CO2 and would be a likely target for CO2 reductions. Compliance with the Kyoto Protocol will require a 33% reduction from the projected year 2012 emission level, even with moderate load growth. This article describes an analysis of power industry CO2 reduction options and their costs. It assesses how a generator would make compliance decisions under a mandatory CO2 emissions reduction program. Carbon sequestration, fuel switching and new plant construction are considered. The Global Climate Change Treaty signed at the Rio de Janiero Earth Summit in June 1992 set the long-term goal of stabilizing CO2 concentration in the atmosphere. The December 1997 Kyoto Protocol established short-term mandatory targets for the United States and 37 other developed countries. The United States' target is a 7% decrease by 2012 from the 1990 "greenhouse gas" level. Developing countries are exempted from reductions, according to the Kyoto Protocol, despite projections that indicate a significant increase in their emission levels. The Kyoto Protocol must be ratified by the US Senate. US power industry carbon emissions were 490 Mt (540 million st) in 1990 and are projected to be 680 Mt (749 million st) in 2012, according to the US Energy Information Administration. Coal-fired generation emits more than 80% of the power sector CO2. Assuming that the power industry is only required to reduce emissions by a proportional share, a 33% emission reduction, or 225 Mt (248 million st) of carbon, would be required to comply with

Jan 1, 1999

By D. Royston

Curved pulp lifters have been incorporated in SAG and AG mills in Australia. The aims have been to ensure complete discharge, at high throughput, of both slurry and coarse solids, especially at high mill rotational speeds. Curved pulp lifters can overcome incomplete discharge and back-flow of solids down the pulp lifter that can occur in straight-radial pulp lifters (and is a major cause of wear). They can be designed to prevent reverse flow of pulp via grates back into the mill. Experience with curved pulp lifters now extends to three years over three mills, in one mill as an installation from new and two as retro-fitted installations. Curved pulp lifters, relative to conventional designs, offer improved discharge and wear performance and well as high impact-resistance and wear life of the curved pulp lifter grates.

Jan 1, 2000

By M. Argiantopoulou

In today?s mining environment, improving production, performance, productivity and profitability is crucial. Production, ancillary, plant and shipping equipment need to be monitored and controlled by online systems delivering production statistics and real-time information to everyone involved, including equipment operators. Traditional systems currently in use today, operate in an iterative mode constantly switching between scheduling and execution. However, the real world tends to change in ways that invalidate such advance schedules. Agent based computing has been hailed as the most significant breakthrough in software development and the new revolution in software. Agent systems are being used in an increasingly wide variety of applications, including complex mission critical systems such as Air Traffic Control. This paper presents the possible ways that multi-agent systems can be applied to mine production and rehabilitation scheduling problems with focus on real time fleet management, plant and equipment performance monitoring, downtime and delay reporting, stockpile management, personnel and equipment tracking and product distribution and transportation.

Jan 1, 2006

By H. Janas

In a gas/coal outburst the gas plays an active, driving part. The proneness of coal to outbursts can be determined by means of its gas emission properties, since coal that is liable to outbursts differs from coal with normal gas emission properties in that it liberates its gas from the sorptive bond more quickly. There is a risk of outburst when the flow of metha¬ne originally desorbed by the coal is sufficient to move the loosened coal which has been broken suddenly. The violence of a gas/coal outburst can be evaluated from the distance of projection of the mass of coal. It depends on the gas pressure and on the liability to outburst of the coal at the original centre of the outburst. Both factors are complementary in their effects so that the same work is done in a gas/coal outburst when there is a high gas pressure and low proneness to outburst as when there is a low gas pressure and a higher proneness to outburst. The gas pressure in the coal increases with its gas content. Consequently it is possible to deduce the gas pressure of a coal seam from its gas content. In the Federal Republic of Germany the risk of a gas/coal outburst is thought to exist when the desorbable gas content of the coal reaches or exceeds the value of 9 m3/ton and if the specific limit value of the proneness to outburst is exeeded. The Mine Ventilation Testing Station of the Westfalische Berggewerkschaftskasse has developed a new method for determining the risk of gas outbursts immediately after taking the samples at the coal face (1), (2).

Jan 1, 1980

By Y. FUJII, E. CHANDA, J. KODAMA, D. FUKUDA, M. NISHIHARA, Y. NAKAYAMA, P. SINKALA

This paper describes a creep damage model that was proposed to clarify the rockburst mechanism for the Mufulira underground copper mine in Zambia. Cumulative rock damage was evaluated for the edge elements of each sidewall of the mining drives based on normal stresses by the 3-D displacement discontinuity method (DDM) (Crouch and Fairhurst, 1973). The rockburst occurrences were well hindcasted.

Jan 1, 2023

By S. R. La Brooy, P. C. Earley

Gold and Resource Developments NL (GRD) operates the Macraes Gold Project in East Otago in the South Island of New Zealand, treating a carbonaceous, refractory sulphidic gold ore. The ore is concentrated by flotation, then reground, followed by CIL cyanidation, to minimise loss to the preg-robbing natural carbonaceous material. As the mine has progressed there has been some variation in the preg-robbing nature of the ore, with average overall gold recovery generally in the range 70- 75 %. The Macraes Gold Project has been operating since 1990 and still has an estimated 11 year mine life, which has stimulated the continuing drive to enhance gold recovery. Testwork in 1994 showed there was no improvement in CIL gold recovery after conventional acid pressure oxidation of Macraes Gold Project flotation concentrate. Hence roasting was initially considered as the preferred option to improve gold recovery, being the only established technology to deal with both carbonaceous preg-robbing and sulphide encapsulation. However Newmont Gold Company pressure oxidation technology, as used at Twin Creeks in Nevada, has proved to be applicable to the Macraes Gold Project concentrate. Pilot scale testwork has shown that both roasting and pressure oxidation could achieve similar CIL gold recoveries on the concentrate. However, capital cost, simpler arsenic stabilisation, the ability to operate autothermally at a lower concentrate sulphur grade and simpler environmental consenting factors, has tipped the balance in favour of pressure oxidation. Overall average gold recovery is expected to improve to approximately 84% with adoption of pressure oxidation. GRD has appointed Minproc Limited as EPCM contractor to install pressure oxidation at the Macraes Gold Project, together with upgrading the existing flotation and grind circuits at a cost of NZ$ 30M (US$ 16M). Construction is 60% complete and on schedule for 1 October 1999 start up.

Jan 1, 1999

By E. G. Williams

Underclays and shales are two natural resources associated with the coal measures. Underclays are widely used as the raw material for refractory, semi-refractory, and face bricks. Shales are useful for sewer pipe and lightweight aggregate. This study concentrates on the geologic controls over the properties of shales for use in the manufacture of lightweight aggregate, and the geologic controls over the properties of underclays for use in the manufacture of bloating ladle refractories. The industrial processes are similar in that both involve the trapping of a gas phase to cause bloating. They differ in that the bloating of lightweight aggregate occurs at lower temperatures (1000-1200°C) than ladle bricks (1350°-1470°C). Lightweight aggregate bloats during an initial rapid firing. Ladle bricks are manufactured by slow firing at 1100°C for up to 80 hours. Bloating occurs when these bricks are reheated to 1350°C . Bloating shales are those which expand twice or more times their original volume during fairly rapid firing. Commercial bloating is usually done by rotary kiln processing or sintering; in both cases the firing rate is much faster than the experimental rate (5/8°C/minute). Bloating results from the entrapment of gasses which are evolved during firing. The material must have adequate viscosity to trap gas bubbles throughout the temperature range of bloating. The finished product contains a high percentage of closed pores with a bulk density between 35-75 pounds per cubic foot. Expanded shale finds its most important use as a substitute for heavy concrete aggregate (crushed stone, sand and gravel) where low bulk density is desired property. The extent of bloating in lightweight aggregate is a function of the mineralogy and chemistry of the shale. Figure 1 shows a corner of the three phase diagram, kaolinite-quartz-(illite and chlorite). Several areas on the diagram are outlined which contain predominantly marine shales, fresh and brackish water shales, and underclays. Each sample was rapid fired and the resulting expansion was plotted on the phase diagram.

Jan 1, 1973

By Sidney A. Hiscock

INTRODUCTION Lead and zinc are today rightly regarded as sister metals. Historically, however, they differ markedly with lead being known and in general use as the metal since 3000 BC in several countries which at that time might have been described as mature economies. Zinc was not isolated and recognised as an industrial metal with distinct and valuable properties until about 1700-1800 AD (although it had, of course, been utilised as a constituent of brass for some 2000 years previously). c were well established as industrial metals by the beginning of the 20th century. The present paper briefly reviews the overall growth in world consumption* and changes in the three main areas which today represent the mature economies or industrialised areas, i. e. ,Europe, the United States and Japan. Trends in overall consumption are determined by the demands for the individual uses for lead and zinc. The changes in patterns of use in the industrialised areas - individually and collectively - and reasons for the changes are also considered. LONG TERM TRENDS - 1900-1984 The World Picture Since the beginning of the 20th century the world consumption of lead (3.9 million tonnes in 1984) has grown almost fourfold and that of zinc (4.7 million tonnes in 1984) is almost eleven times greater than it was in 1900. The long-term trend has been one of continuing expansion for both. metals although the pattern has been severely disturbed at certain periods, for example in the years immediately following the two world wars and at times of marked recessions in industrialised areas. Apart from such major setbacks, new levels of consumption have been established regularly every few years. Recently, however, consumption has not really grown and with only a slow and partial recovery in world industrial activity at present, there is no indication that the peak consumptions of 4.2 million tonnes of lead, set in 1979, and 4.8 million tonnes of zinc (1973) will be exceeded in the near future. The growth in world lead and zinc consumption since 1900 is shown in Figure 1 (which includes changes in copper and aluminium for comparison). Overall growth over the period 1900-1984 has been about two percent a year for lead and about three percent for zinc (annual growth for copper has also been about three percent). Increases in tonnage consumption and growth rates by decade for lead and zinc are summarised in Table I. However, the growth rates by decade sometimes conceal very large individual annual increases and decreases. For example, in 1975 lead consumption fell by 13 percent and zinc consumption by 22 percent compared to 1974. In 1976 consumption of lead and zinc rose by 12 percent and 18 percent respectively. The years when consumption 'landmarks' (ie one, two, three and four million tonnes) were first reached are shown on Table 2. Clearly, the pattern of shorter periods being required to attain each extra million tonnes of consumption was broken in the 1970's. The consumption of zinc overtook that of lead for the first time in 1940, and since 1946 has always been at a higher level. Trends in industrialised areas The two key industrialised areas at the beginning of the 20th century were Europe and the United States which between them accounted for some 95 percent of world lead consumption and 98 percent of zinc consumption. Figures 2 and 3 show the growth in lead and zinc consumption, and Figures 4 and 5 the percentage shares for each area since 1900. Europe has usually been the major user of lead except for some years in the 1920fs, most of the 40's and early 50's when consumption in the United States was larger. In 1900, Europe accounted for about 64 percent of world lead consumption and the United States just over 30 percent. Currently, Europe takes about 40 percent of world consumption and the

Jan 1, 1986

By R. E. Mason

Shotcrete has been used for approximately 20 years to facilitate tunnel excavation through poor ground. Early examples of such usage in North America include the recuperation of the Granduc Mines access tunnel in Northern British Columbia, and similar work performed in the Carley V. Porter and Big Walker Tunnels in the United States. Mining companies such as Craigmont Mines in B.C. and Hecla Mines have used shotcrete in their workings for the past ten years. Shotcrete is now a widely utilized fool in the mining and tunnel construction industries in North America, but the accumulated experience is too limited for many to fully appreciate the capability of shotcrete to control ground movements and to understand the limitations of this tool. It is common, for instance, to use shotcrete to "bridge the gap" between rock bolt-supported and steel-rib supported ground and to avoid the use of shotcrete in water-bearing ground. Shotcrete can, and has been, used economically and practically under most severe ground conditions.

Jan 1, 1976

By Robert E. Goodwin

There are four main requirements which must be considered when selecting a wire rope for the best serviceability. A proper choice is made by correctly estimating the relative importance of each of these requirements and selecting s rope which has those qualities best suited to withstand the combination of destructive forces expected under continued service. A wire rope should possess: 1. Strength sufficient to support the maximum load expected and with s proper safety factor. 2. Ability to withstand bending and to resist bending fatigue without failure of the wires. 3. Ability to withstand surface abuse such so abrasive wear, pounding, and wire scrubbing. 4. Ability to withstand abuse such as crushing and distortion.

Jan 1, 1968

By Arnolfo A. Valdivia

Prior to 1971, there were several clinical trials to evaluate programs for early detection of lung cancer. Among these, the Philadelphia Pulmonary Neoplasm Research Project,(3) the Veterans Administration Study published by Lilienfeld,(7) and the controlled trial of the Kaiser Foundation Health Plan showed an overall five year survival rate of 8% for newly detected cases (the same as the national statistic for unscreened patients). In 1971, the National Cancer Institute initiated three randomized, controlled mortality studies using lung cancer screening of persons at high risk (male smokers over 45 years old). The studies are being conducted at the Johns Hopkins University Hospital, the Mayo Clinic, and the Memorial Sloan-Kettering Cancer Center. The studies have slightly different designs in the combination of sputum cytology and chest x-rays. At the Mayo Clinic the study group is offered screening with sputum cytology and chest x-rays every four months, whereas the control group is advised to have an x-ray and cytology every year. No reminders are sent, and it is believed that only about 20% of the control group is screened. At Johns Hopkins and Memorial, both experimental and control groups are offered annual chest x-rays. The experimental group is additionally offered sputum cytology every four months.(5) At present all of the programs show that screening can detect cancers that are undetectible by other means. However, at this time mortality rates in the control and experimental groups are not significantly different in any of the three studies. OUR PROGRAM Our clinic is located in Grants, New Mexico and we provide most of the pre-employment physical examinations for the mines operating in the Grants area (Kerr McGee Nuclear, Homestake Mining, United Nuclear, Western Nuclear, and Ranchers). In the examinations, we obtain the previous mining history of the worker, a chest x-ray, a sample of sputum for cytological examination, and a blood sample. We also provide routine annual physical examinations of the workers, with special interest in the detection of bronchogenic carcinoma. In the early seventies, we did not have a definite surveillance program. We did not know whether we should have a program like the one started at Memorial or like the one started at the Mayo Clinic. After long consideration, we decided to have a program that does not demand a sputum cytology and chest x-ray every four months, but that allows as many chest x-rays and sputum cytologies as needed to diagnose lung cancer as early as possible. We believe that, if a screening method for cancer is to be optimally effective, it must detect the process at stages early enough for curative therapy. We order a test depending on the age of the miner, the race, the mining history, the smoking history, the radiation exposure levels, and the results of the previous chest x-ray and sputum cytology. With the help of the computer, we have a list of all the miners who should be watched closely because of age, race, mining history, smoking history, radiation exposure, etc. Examination of the miners is performed at our clinic, where all the records are kept. The sputum is collected there but examined in Grand Junction, Colorado, by Dr. Geno Saccomanno. There are two ways to collect sputum. The best way is to collect three consecutive morning samples. For this, we need the cooperation of the miners. They have to follow these instructions and mail the bottle containing the sample to Grand Junction. "Instructions for obtaining a good cough specimen" The enclosed plastic bottle contains a preservative solution, so do not empty out the liquid in it. When you go to bed, place the plastic bottle at your bedside where it will be handy in the morning. When you first get up in the morning (before breakfast) try to cough up some "phlegm" from deep in your chest, and spit it into the liquid in the bottle. Try coughing several times. If you have difficulty coughing, try inhaling deeply the steam from a teakettle (or home-type inhalator). Keep the amount of saliva (ordinary spit) that you put into the bottle along with the cough specimen as small as possible. Do not collect the "phlegm" or mucous that comes from the back of your nose. Put the cap back on the bottle, and shake it vigorously for two minutes. If the amount of material you have coughed up is quite small, then keep the bottle at your bedside for three or four days, and each morning try to add another cough specimen. After obtaining your cough specimen, repack the bottle in the mailing container, and attach the enclosed mailing label. It does not require any postage stamps. Unfortunately, some miners "forget" to mail the sample and end up with an incomplete physical examination. To avoid this some companies, like Homestake, request that we obtain the sample in our clinic by forcing cough and expectorant with a nebulizer machine. This method does not give as good a sputum sample as the previous one, but we do get a sputum sample for every miner. The policies of different companies, in regard to annual physical examinations are different. All

Jan 1, 1981

By Priscilla P. Nelson, Francis L. C. Fong

Introduction Fracture mechanics is the study of the behavior of cracks and their modes of propagation. During cracking, energy is consumed in creating new surface area. The more energy a material absorbs, the higher is its fracture resistance. This fracture energy is provided either by work done externally, by the release of elastic strain energy within the cracked body, or by a combination of these two effects. Fracture resistance is measured in terms of either the stress intensity factor, K, or the energy release rate (also referred to as crack driving force), G. For linearly elastic materials, these two quantities are related by the following equation: [ ] where [u] is Poisson's ratio and E is the modulus of elasticity. Both K and G are direct functions of the applied force and the crack length. The process of rock cutting with full-face tunnel boring machines (TBMs) involves the indentation of a rock surface by rolling disc tools. Excavation occurs as fractures, extending from the locus of chip indentation, propagate between concentric disc grooves and liberate rock chips from the intact rock face. Since disc cutting is achieved by a fracture process, it is logical to anticipate that differences in cuttability of a variety of rocks should be related to the variation of fracture material properties among the rocks. Such a relation has been demonstrated between the performance of full-face TBMs and the critical crack driving force for excavation in relatively high strength, brittle, low porosity, isotropic rock (Nelson et al., 1985). The objective of this paper is to report on the results of a continued investigation of the relationship between fracture material properties and the effectiveness of disc cutting. Additional reliable data on full-face TBM performance is difficult to obtain, so that the results of disc linear cutter tests performed by the Transport and Road Research Laboratory (TRRL) (U.K.) are utilized in this study. Fracture Material Property Evaluation If a crack tip is subjected to a perfectly plain strain condition, many materials will behave in a brittle manner, and the material resistance to fracture is constant during crack growth. This resistance is referred to as the plain strain fracture toughness, believed to be a material property. The standard testing procedure for this parameter is given in the American Society for Testing and Materials (ASTM) test designation E399. To ensure plain strain conditions, acceptable specimen geometries are specified. Unless these geometric specifications are adhered to, the measured fracture resistance is regarded as the apparent fracture toughness, and a subscript Q is used, as [ ]. The methodology adopted by ASTM E399 is within the framework of Linear Elastic Fracture Mechanics (LEFM). This approach assumes that material resistance against cracking is developed instantaneously, without initial stable or subcritical crack extension. Prior to crack advancement in rock, however, much of the crack driving energy is absorbed in a localized volume in front of the crack tip, referred to as the plasticity or microcracking zone. This capability for energy absorption substantially increases material resistance, and a crack may be arrested unless an increased crack driving force is applied. The LEFM or plain strain assumptions would underestimate the actual fracture resistance of such a material. Such a conservative approximation may be desirable in the design of structures against fatigue or brittle failure. In mining or tunneling, however, an underestimation of crack resistance can lead to the selection of underrated excavation equipment and a decrease in production efficiency. The development of fracture resistance in rock is best described by the material resistance curve, or R-curve, which is a plot of fracture resistance as a function of crack extension. Typically, peak resistance is only reached after a finite amount of subcritical crack growth. The

Jan 1, 1986

By J. M. Applegate, C. L. Morgan

Introduction In the same way that a blueprint communicates informa¬tion about a structure, a systems architecture should provide information that guides the construction and implementation of a computing system. Taking the blueprint analogy a step further, a plot plan can also show where, in the "bigger picture," a particular design fits (if in fact it does) and what a builder needs to know about the environment in which he or she will operate. In the context of business systems, a meaningful architecture should convey the following: • the primary purpose of computer-based systems rela¬tive to particular tasks or operations, • the relationship of the systems to each other and an indication of their interaction and dependencies, • the relationship of the systems relative to the organiza¬tion and its objectives, • indications of where IS/IT resources can best be allo¬cated to support the organization and • the overall context in which new systems and technolo¬gies can be assessed for both their impacts on current systems and on the organization itself. In theory, a well-designed systems architecture should allow an organization to focus its resources on those aspects of its business that matter most, thus, leveraging investments in information technology to a competitive advantage. In addition, the way that a computing systems architecture is represented should be un¬derstandable to non-IT staff, and it should be eas¬ily recognized by the people it supports. This pa¬per attempts to show that a meaningful systems model exists and that its applica¬tion to mining can achieve the desired results. The following discus¬sion is based on the au¬thors interpretation of a concept referred to as the computer integrated manu¬acturing (CIM) model, as developed by Allen-Bradley. An inherent strength of the CIM approach is that the model combines aspects of business-reporting structures with the manufacturing process itself. What results is a systems frame¬work that is aligned with relevant business processes and is, therefore, easier for non-IS/IT personnel to interpret. The successful application of the CIM model can be seen in a large number of both discrete and process-manufacturing facilities throughout the United States. This paper provides a brief overview of the CIM model and then describes how the model can be applied at a conceptual level to the mining industry. Finally, this paper proposes an extension to the CIM model that the authors believe will make it easier to understand and apply. CIM model As shown on Fig. 1, the CIM model begins with the most detailed levels of process equipment and works its way up to the highest level of consolidated financial reporting. Systems at each level are characterized by common attributes, users, time frames, etc., providing a clear picture of their interac¬tion. Further analysis of the relationships between systems and between levels provides insight into the opportunities for integration. Regardless of the industry or processes involved, the CIM model provides a framework in which the characteristics of systems and the data they manage can be predicted based on the nature of the business function they support. In general, as data moves upward from the lower rungs of the CIM model, it changes from de¬scribing the physical na¬ture of a process to describ¬ing its financial aspects (e.g., from productivity to cost). The time frame to which data applies also transitions from a very short duration, perhaps only milliseconds, to financial or regulatory reporting time frames that may span years. In a simi¬

Jan 1, 2000

By David E. Thompson, Daniel J. Dobbels

INTRODUCTION The planning process for projects requiring construction of tunnels in urban environments can be highly complex and involves interaction with professionals of many disciplines. Typically the initial step in the planning process is to establish basic design criteria for the tunnel or tunnel system consistent with its intended purpose. Such criteria might include acceptable tunnel geometry, minimum and maximum slope or other associated criteria. Ideally, once the basic criteria have been established, the next step in the process might include establishing technically feasible horizontal and vertical alignment and shaft siting alternatives and developing "ball park" construction and operational cost estimates for the alternatives. Comparisons can then be made regarding the relative technical and economic merits of the alternatives and the most favorable alignment(s) are selected for further study or preliminary design. Typically the last and perhaps the most important task that is conducted during the planning stage includes identifying issues and potential problems to be addressed during the design and construction stages of the project. Many issues warrant consideration during the planning phase of a tunneling project. For the purposes of this paper, these issues can be divided into two broad categories: technical and non-technical. Important technical issues include, among others, general design criteria, geotechnical and geoenvironmental issues, and constructibility issues. Important non-technical issues include, among others, right-of-way and easement related considerations, project scheduling constraints, both short and long term environmental impacts and overall cost/benefit aspects of the project. With respect to influence on the planning process, these two groups of issues often cannot be separated completely. For urban tunneling projects, however, it is most often the case that the non-technical

Jan 1, 1991

By Michael Elliot-Jones

The fundamental competitive structure in world coal markets will be modified by the entry of such new participants as Colombia and the newer mines in South Africa. The US will, in most markets remain the swing producer, although a number of low cost US mines will continue to compete in world markets. Exchange rate swings will persist as a major hazard for coal exporters.

Jan 1, 1986

By R. Poulin, R. Pakalnis, D. Peterson

Introduction A comprehensive project has been completed at the University of British Columbia that focused on the development of a commercially competitive composite cable bolt. Laboratory evaluation consisted of pull tests, preliminary shear tests, grout column testing and scanning electron microscope evaluation of the composite cable bolt. Field implementation at five underground mines throughout Canada were completed for technical and overall performance evaluation of the new product. The project began in 1989 under the sponsorship of HDRK Ltd., a consortium of mining companies including Inco, Noranda and Falconbridge Ltd. The objective was to develop a cuttable cable bolt that would serve as support for a continuous miner within a hardrock environment (Mah, 1994). The bolt was required to be cuttable by a continuous roadheader without adverse effects to equipment, personnel and the milling process. From the beginning, the focus was to employ existing cable bolt installation technology (Goris et al., 1994) whereby the cable bolts are grouted within a 4.8-cm-diam (1.08-in.diam) or larger employing a portland cement grout having a water: cement ratio between 0.35:1 to 0.4:1. The prototype, developed from Phase I, was technically comparable to that of conventional steel cable bolts. However, high cost and limited accessibility hindered its commercial acceptance. The second phase of the project was sponsored by the British Columbia Science Council and Pacific Pultrusions Ltd. of British Columbia to locally develop a glass fiber cable bolt. This phase of the project has resulted in the DAPPAM cable bolt (Pakalnis et al., 1994). DAPPAM Cable bolts are the second most used support method in Canadian underground mines after mechanical rock bolts. It is projected that 870,000 m (2.9 million ft) of cable bolts are installed annually in Canada (Poulin et al, 1994). The objective of the research program was to develop a glass fiber cable bolt with similar pullout strengths to the conventional steel cable bolts (267 kN - 60,000 lbf). More than 200 laboratory pull tests were conducted employing standard cable bolt test procedures, as outlined by the US Bureau of Mines (Goris, 1994), to assess optimum rod and surface composition, geometry, number required, pullout and shear characteristics, among others. This resulted in the DAPPAM cable bolt (Fig. 1). It consists of 10 individual 0.6cm-diam (0.25-in.-diam) rods enveloping a 2.2-cm (0.8-in.) outside diameter, high-density polyvinyl grout tube. The composite used in the construction of the rods is comprised of about 65% glass fiber within a 35% polyester resin matrix (by volume). Through pultrusion (a continuous fabrication technique), the fibers and resin are combined into a composite material. The strength of the overall composite is largely governed by the material properties, the alignment [ ] of the fibers relative to the applied load and the density and interaction of the overall components within the composite. A further modification to the composite was the addition of a sand grit to the surface of the individual rod. This increased the overall bond strength between the rod and the cement-based grout, used to solidify the cable bolt to the rock mass. The grout tube has an inside diameter of 1.9 cm (0.75 in.) and is rated at a pressure of 1.72 MPa (250 psi). During installation, the grout is pumped through the annulus of the grout tube thereby filling the hole from toe to collar. Laboratory and field trials concluded that a minimum drill hole diameter of 4.8 cm (1.08 in.) be used to ensure optimum grout coverage. Table 1 compares the design strengths (as tested) for DAPPAM vs. the ultimate strengths for a conventional 1.6cm (0.6-in.) steel cable bolt. The characteristics for the steel cable have been derived directly or indirectly by Goris et al. (1994). A design tensile strength of 289 kN (65,000 lbf) was proposed for the composite developed. However, recent tests have indicated maximum breaking strengths of more than 400 kN (90,000 lbf) (Fig. 2). Figure 2 shows the load vs. displacement pull out curves for steel and DAPPAM cable bolts. The methods of testing were standardized so as to be able to compare the results directly. The shear strength of the fiberglass cable is largely a function of the surface area sheared. Shear strengths of 89 kN (20,045 lbf) were obtained for the configuration shown in Fig. 1 when sheared normal to the axis of the cable. The testing procedure was similar to the shear tests performed on steel by Goris (1993). It is important to reinforce the implication that critical bond strength has on the success of an overall support system.

Jan 1, 1995

By Steven J. Schafrik, Michael Karmis, Zacharias Agioutantis

3-D or pseudo 3-D visualization of orebodies and mining related processes such as loading and tramming, are now commonly used by the mining industry. An approach is presented that can aid the engineer in creating the visualizations necessary for accurate presentations for use in public relations, safety training, production projections, reclamation plans, etc. It is shown that the creation of such digital representations of mining environments are independent of the mining package used to create the original mine design. Once a proper model has been created, any view of the areas is possible. These views can be taken from any number of stationary points or entered into an animation showing the progress of a mining construction. The paper focuses on the presentation of the steps used to accomplish the visualization and an example is for a quarry fill placement project.

Jan 1, 2002

By P. K. Berger, G. T. Lineberry, H. P. Cole, J. V. Haley

Sixty-five simulation exercises were developed for teaching and testing problem solving and decision making skills to miners and mining engineers. The exercises focused on judgment and decision making for preventing and controlling mine emergencies. The structure and field testing of the exercises are described, and sample frames of individual exercises are presented. Empirical data are summarized about the effectiveness of these simulations based on the performance scores of a national sample of miners and mining engineers.

Jan 1, 1994