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By T. G. Carter

"This paper traces the introduction and use of fire-resistant (FR) fluids in hydraulic systems at underground mines in British Columbia. Reasons are given for the decision to make compulsory the use of such fluids in underground mines after January 1, 1975 by provincial government legislation. Examples are quoted of fires caused, or supported by, mineral oils which have resulted in loss of life and property.The basic principles of hydraulic systems are reviewed in order to present the effects of changing a system operating on mineral oils to one which must operate on FR fluids. Approximations of the cost of system conversions are given for certain machines and a brief survey is made of the various pieces of underground equipment which contain hydraulic systems operating on FR fluids.IntroductionIn 1948, Admiral Ben Moreel , who was then president of Jones and Laughlin Steel Corporation in the United States , wrote:""Although safe and healthful working conditions can be justified on a cold dollars-and- cents basis, I prefer to justify them on the basic principle that it is the right thing to do. ""(1)This paper will outline the introduction and use of fire resistant fluids at mine operations in the Province of British Columbia. That it was the right thing to do in enhancing the safety and well-being of every person employed at the mines was the prime consideration. That it may be justified on a cold dollars-and-cents basis is left for the reader to judge. The prime purpose of this paper is not so much to trace the efforts made by the individual mines to successfully introduce and use fire-resistant (FR) fluids in hydraulic systems, but to present an over-all picture of what occurred, in a collective sense, at the majority of mines which have ended up with a working FR fluid system. The problems attendant to the introduction of an FR fluid will be recounted in a manner which, it is hoped, will prove useful to those contemplating system conversions. Because the predominant fluid now in use is an invert, or water-in-oil. emulsion, this will be the FR fluid considered.Fluid Loss from SystemsThe quantities of various fluids required for use in hydraulic systems are extremely high. This statement in itself may appear to be redundant in that the capacities of the various systems should demand that a fixed amount of fluid is required for the initial filling of a system, with a further amount of fluid scheduled for use during subsequent fluid changes, i.e. at the recommended change intervals . If only this were the case!"

Jan 1, 1981

By Sukumar Bandopadhyay, Arunapuram Sundararajan

"For the last three decades, the application of network planning has provided a basis for a formal and general approach to the discipline of project management. For fixed activity duration, a very simple algorithm commonly known as critical path method (CPM), gives the length of time required for the total project as well as indicates the activities which are vital to the completion of a project. Project Evaluation Review Techniques (PER T) on the other hand, generalize the above approach to recognize uncertainty in the activity durations by allowing them to be random variables. One of the misleading aspects of current "" PER T"" solution method is, however, the implication that there is a unique critical path. In general, any number of paths could be critical, depending on the particular realization of the random activity durations that actually occur. In this case, simulation can be utilized to estimate completion time of a project.In this paper, the concept of criticality indexing is discussed, and a simulation model application which defines the critical path based on the criticality indexing concept, to a longwall development - extraction network, is presented. The model also provides suitable scheduling of resources based on the resource constraints and smooth s out period-t o-period assignments. IntroductionThe successful management of large-scale projects require careful planning, scheduling , and coordinating numerous interrelated activities. To aid in these task s, formal procedures based on the networks and network techniques (variously called PERT or CPM) were developed. In its original form the completion time for individual activities of a project was assumed fixed and known in advance: this in turn led to the familiar algorithms for computing the critical path, earliest start time, slack, and so forth. The unreality of such an assumption is, of course , apparent in many contexts. Consequently, attempts were made to introduce probalistic activity completion times, allowing representation of the stochastic nature of most projects."

Jan 1, 1987

By A. M. Cann, C. I. Godwin

"The Kemess porphyry copper-molybdenum deposit occurs in the Intermontane Belt of north-central British Columbia. The deposit is in andesitic to basaltic flows and tuffs which may be correlated with the Savage Mountain Formation of the Upper Triassic Takla Group. Most known chalcopyrite and molybdenite is associated closely with a 500-m-diameter zone of intense quartz-sericite-pyrite alteration. A zone of supergene enrichment, up to 30 m thick, underlies a leached capping about 20 m thick. The age of mineralization and the surrounding granodiorite and quartz monzonite pluton is Early Jurassic. K-Ar and Rb-Sr analyses indicate that the mineralization and alteration is slightly younger (l82±6 Ma) than the granitic intrusion (KAr: about 205±6 Ma; Rb-Sr: 190±4 Ma). The low 87Sr/J6Sr initial ratio for the granodiorite is typical of plutons in the Intermontane Belt.IntroductionKemess is a medium to small porphyry copper-molybdenum deposit with significant gold and silver values (Pilcher and McDougall, 1976). This paper describes the lithologies and alteration at this property; geochronology by Rb-Sr and K-Ar methods defines the ages of mineralization and surrounding plutons to be Early Jurassic.The property, located in the Thutade Lake area of northcentral British Columbia (NTS Map 94E; lat. 57°04'N; long. 126°44'W), is about 425 km northwest of Prince George (Fig. 1). Closest road access is 35 km southeast of Kemess. Final access must be by float plane or helicopter. The British Columbia Railway right of way passes 70 km to the southwest of theproperty.A prominent gossan zone at Kemess was staked in 1967 by Kennco Explorations (Western) Ltd. following detection of geochemical anomalies during stream sampling the previous year. During 1968, 1969and 1971, Kennco completed 232 m of X-ray diamond drilling, conducted geological mapping and carried out geochemical sampling of silts and soils (Stevenson, 1969; B.C. Ministry of Energy, Mines and Petroleum Resources, G.E .M., 1969 and 1971). Getty Mines Ltd. optioned Kemess in 1975and 1976. They remapped the area and diamond drilled 12 BQ and NQ holes, totalling 2065 m (B.C. Ministry of Energy, Mines and Petroleum Resources, Expl. B.C., 1975)."

Jan 1, 1980

By D. Assmus, S. Daly

"Poor fragmentation, high toe areas, excessive shovel wear and tear and frequent re-drilling and blasting of certain tough waste rock zones in the Lomex pit in the early 1980snecessitateda better understanding of these zones.A combination of geotechnical mapping, penetration rate data, toe elevation contouring and observations on shovel and drill performance were used to determine the character and extent of these zones. This complementary information was brought together by the geotechnical mapper and the explosives supervisor.Distinct zones with particular geological characteristics were determined. A classification system with three types of blast and dig-ability was developed for the Lomex pit and later applied to the Valley pit, with considerable success. The three blast zone types are called ""poor"", ""f air"", and ""good"". This system will be described in detail.The explosives supervisor adjusted the blasting parameters to each zone, in particular, pattern spacing and burden. The resulting powder factors showed considerable variation between the poor, fair and good zones within each pit as well as between the two pits. Pattern geometry and length of collar were also adjusted to improve fragmentation. Cost savings resulted from less re-drilling and less wear and tear on drills and shovels in the poor zones and more efficient use of explosives in all the zones. An annual estimated cost savings of well in excess of $1,000,000 is realized at Highland Valley Copper. A by-product of the mapping was the determination of unstable structures and water flowing zones. Blasting was then adapted to this information for enhanced slope stability."

Jan 1, 1992

By Neil Schofield

"The Pine Creek gold mineralization is associated with saddle reefs and quartz and quartz sulphide veining within the Enterprise Anticline. The anticlinal structure is complex and the mineralization was considered prior to development to be dominantly strata controlled. Gold grades vary up to 160 gin 1.5 m core samples with coefficients of variation in excess of three.The estimation of ore reserves for such a deposit must account for both the geological complexity and the extreme variability of gold grade.This paper describes the structural and variogram analysis of the gold grades and demonstrates the importance of incorporating the geological model in such an analysis. Variogram interpretation is greatly improved and greater insights into the finer geological structure areprovided. Part 2ofthis work presents the application of multigaussian kriging to reserve estimation for deposits with highly variable grade and which consequently demand highly selective mining operations. IntroductionThe Enterprise Gold Mine is situated some 220 km southeast of Darwin in Australia's tropical north. Gold is believed to have been discovered there in 1869 during the construction of the overland telegraph line.From 1894to 1915, some 75 000 ounces of gold were produced from 121 000 tonnes mined mainly by Chinese leaseholders. From 1906 to 1915, government-sponsored drilling led to the sinking of the Enterprise Shaft to 79 m and several drives were developed. Mining ceased because of war.Since late 1980, Goldfields Exploration Pty. Ltd. had explored on several mining tenements near Pine Creek under joint venture with the title holders, Enterprise Mines NL. This work culminated in the development of the current mine which opened on October 29, 1985.Feasibility studies to determine the economic viability of mining were based on ore reserves generated by project geologists using a sectional polygonal approach tuned to the interpreted geological control of the mineralization.The study motivating this two-part paper covers are-estimation of the recoverable reserve s using the geostatistical approach of multigaussian kriging developed at Stanford University, (Verly, 1984)."

Jan 1, 1988

By Ross L. Sherlock, David J. Scott, Gordon MacKay, Wayne Johnson

"Abstract - The demographics of Nunavut indicate a very young and poorly educated population spread over wide areas in small isolated communities. The current economic sectors will be unable to expand and meet the demands of this emerging workforce. Given the realities of Nunavut, the most promising direction in which the economy may expand is through mineral development. The Nunavut Land Claims Agreement (NLCA) has established the legislative framework for sustainable development in Nunavut through mineral development. The NLCA has transferred ownership for much of Nunavut’s potential mineral resources to beneficiaries of the lands claim. Royalties generated from mining operations on subsurface Inuit-owned lands, and to a lesser extent on Crown land, will flow back to beneficiaries of the lands claim through their administrative company, which may then be invested in the communities. Additional benefits of mineral resource development in Nunavut will be realized through impact and benefit agreements.To realize the benefits from mining operations, Nunavut has to be able to attract and support exploration and development companies through the release of high-quality geoscience data. However, due to Nunavut’s isolation and the expense of conducting geoscience fieldwork, the jurisdiction lags far behind the rest of Canada in terms of quality and quantity of government geoscience. About 70% of the territory is inadequately mapped to attract exploration companies or to make informed land-use decisions. The role of government-funded geoscience in Nunavut is to stimulate exploration and discovery through new framework mapping and focused thematic projects. The timely delivery of high-quality geoscience products will attract exploration companies to Nunavut and further their efforts to discover and develop mineral resources in order that the subsequent benefits of this activity may flow to the beneficiaries of the NLCA as well as all other residents of Nunavut."

Jan 1, 2003

By P. Rocque, S. Talebi

Although the measurement of blast vibration close to the blasthole is critical to the understanding of rock fragmentation mechanisms and blast damage in the rock masses, limited experience for such monitoring exists. Because much higher vibration amplitude and frequency ranges are expected in rock masses close to an explosive charge as compared to far field vibrations, different problems from those for the far field monitoring must be considered for near field blast vibration monitoring. Currently, guidelines for design of the near field blast monitoring systems do not exist. This paper describes the development of an integrated technique for vibration monitoring close to a blast hole, including selection and installation of transducers, design of a monitoring system and signal recording. A densified cement was designed for grouting accelerometers in order to match p-wave impedance between the rock and grout. The monitoring technique described has proven suitable for blast vibration monitoring within 2 m to 15 m of a blast hole having loading conditions similar to production blasts.

Jan 1, 1993

By R. W. Lawrence, A. Bruynesteyn

"Pre-oxidation of refractory pyritic concentrates by biological leaching to enhance the recovery of gold and silver in cyan ideation has been investigated. The results of laboratory tests on three concentrates are presented. In all cases substantial increases in precious metal recoveries were obtained following the pre-treatment. For one concentrate, gold recovery of 81% was achieved following an 87% oxidation of pyrite, compared with 24% recovery by direct cyanidation of non-oxidized concentrate. Gold and silver recoveries from the other concentrates were increased from the range 60-78% to over 90% and from 80-86% to over 98% respectively. Operating parameters are discussed and methods of maintaining high oxidation rates are evaluated. Methods of employing this pre-oxidation technique in commercial practice are described.IntroductionMany of the gold and silver deposits now being developed contain precious metals finely disseminated in sulphide minerals such as pyrite. These ore s often present considerable resistance to metal recovery. The ease with which gold may be extracted is usually related to grain size and its manner of distribution within the host mineral. In many cases, a significant percentage of the gold may occur in submicroscopic form, or in solid solution with pyrite, so that even very fine grinding fail s to liberate the metal for recovery by cyanide leaching. Such ores are often termed refractory. Even in cases where liberation by fine grinding is practicable, high cyanide and lime consumption may be experienced due to the presence of specific sulphide minerals, and poor metal recovery may result.Pre-oxidation methods for refractory ore s and concentrates are commonly used to improve precious metal recoveries. Roasting, for example, as a pre-treatment to cyanidation, removes harmful constituents by oxidation or volatilization, and liberates gold from pyrite. In some cases, however, this method of pre-oxidation can result in poorer metal recovery, particularly of silver, due to fusion and the formation of clinker, and the formation of compounds which consume cyanide in the subsequent metal recovery stage. Difficulties in compliance with environmental pollution regulations may also be encountered."

Jan 1, 1983

By C. Dodds, R. S. Ferrari-John, The University of Nottingham, G. Dimitrakis, J. Katrib, A. R. Batchelor

"Sorting technologies have the potential to reduce energy use in comminution by rejecting uneconomic ore before feed material enters the mill. However, a major challenge for sorting porphyry copper ores is providing a basis of discrimination between valuable and non-valuable fragments, due to their complex mineralogies and textural features. Microwave heating in combination with infra-red detection (MW-IR) has been shown to provide upgraded feedstock for certain ores at bench scale. Selective heating of copper sulphide minerals compared to the gangue leads to an increased thermal response for valuable fragments, providing the basis for sorting.Rapid scale up of MW-IR from bench scale to a 100 t/h continuous pilot plant facility has been facilitated by the design of microwave choking structures to allow continuous operation at industrially meaningful throughputs, whilst meeting health and safety and electromagnetic compliance standards, and the integration of materials handling with electromagnetic systems.Laboratory batch testing on a pilot scale microwave system has been undertaken to investigate the thermal response of copper ores under industrial conditions, at microwave energy inputs up to 1 kWh/t. These results provided the operating window and recommended test conditions for the continuous pilot plant. Sortability curves predicted in the laboratory are in good agreement with separations achieved during continuous pilot plant operations. The potential microwave sortability of a number of ores has been studied, allowing informed decisions to be made about potential ore candidates based on mineralogy. Future development of the technology will be underpinned by the creation and validation of scale up concepts for 1000 t/h operations. Understanding the value proposition for individual sites/applications will be central to unlocking the potential economic and environmental benefits of microwave sorting."

Jan 1, 2016

By J. R. Gill

Introduction The property and plant of the Falconbridge Nickel Mines, Limited, is situated about 13 miles northeast from Sudbury, in Falconbridge township, near the eastern extremity of the southern Nickel Range. As early as 1899 or 1900 some work was clone on this property by the late Thos. A. Edison, when a shaft was sunk through 80 feet of overburden to within a few feet of the ore-body. At this point quicksand was encountered, which made it impossible to continue with the equipment at hand. As a result, the activities of the Edison party ceased in this section. There was no further progress until 1915 and 1916, when an extensive diamond-drilling campaign, carried out by the E. J. Longyear Company, located the ore-body that is now being worked. The property was acquired by the present operators in 1928, and in September of that year active mining development was commenced. Features Influencing Design Of Plant Early in 1929 plans were prepared for a smelter and the necessary crushing and sorting plant. In spite of the general trend towards the reverberatory furnace as a smelting unit, it was decided to erect a blast-furnace plant. The limited tonnage to be treated, of course, influenced this decision to a great extent. However, it was known that, with the proper procedure, extremely favourable results, both economic and metallurgical, could be obtained in blast furnace smelting. The possibility of very low slag losses, the simplicity of operation by the elimination of roasting plant, fuel plant, etc., the ability to handle coarse feed, and the lower initial cost, were considered factors in favour of the blast furnace. Notwithstanding the fact that we might be called on to treat a certain amount of concentrate, it appeared that the blast furnace was the proper unit for the contemplated operation.

Jan 1, 1932

By Zhen Lei

In Alberta, Canada, heavy industrial projects are constructed using a prefabrication approach: spools and pipes are produced in the factory, and are assembled into modules that are transported to the industrial plants for installation by mobile cranes. Planning the onsite mobile crane operations is critical to the project budget and schedule. However, due to the large magnitude of industrial projects, manual heavy lift planning is tedious, and the results are not particularly responsive to site changes. This paper introduces an integrated mobile crane management system developed by PCL Industrial Management Inc., in collaboration with the University of Alberta, which investigates crane location selection and path checking for field module assembly. The project information is stored in a database, and the proposed system retrieves data, performs the calculations, and records the results back to the database; the calculations involve automatically selecting locations for the mobile crane, considering the crane capacity, lifting range and utilization. Lift paths for modules are checked for feasibility based on selected locations, satisfying the site and crane configuration constraints, and crane walking paths are planned if needed. The designed system is tested in an industrial project to validate the effectiveness of the system.

Aug 1, 2013

By Paul G. Dunn

The planning of underground mines is a complicated process involving geological, engineering and operational constraints. MIRARCO is in the process of developing a 5D Mining Exploratorium where 3D mining models are combined with time (4th dimension) and costs (5th dimension). The mining exploratorium is a collection of external and inhouse software packages specifically geared to help underground mining companies arrive at better mine plans. This paper discusses the progress made in the development of the 5D Mining Exploratorium and a change in mine planning philosophy by conducting frequent audits in a Virtual Reality Laboratory. The development of genetic algorithms for optimising stope sequences is also presented.

May 1, 2003

By Sophia Wong

Nickel is used in a wide variety of applications from consumer goods to industrial uses. In many of these uses, nickel contributes to the environmental attributes of the product. The challenge, however, is measuring that contribution, comparing it to the environmental cost of production, and communicating the role of nickel to the customer in a way that is easy to understand. This paper presents the Nickel Institute?s approach to climate change as a global commodity industry association, and discusses where we stand with regard to some of these key questions. It also identifies issues for the nickel industry moving forward ? challenges that are likely to be common to other commodities.

May 1, 2009

By H. Soto, P. Lacombe, R. del Villar

"During the summer of1989, Les Mines Selbaie, with the cooperation of Université Laval initiated a research project to evaluate the column flotation technology for its concentrator near Joutel, Quebec. The experimental work involved both a 5 cm by 11 m laboratory column and a 45 cm by 10 m home-made pilot unit Amenability tests were conducted using both units on various streams of the plant. Results showed that columns are not suitable for the copper cleaning circuit because the loss of precious metals, associated with the rejected pyrite, overcome the improved copper metallurgy. On the other hand, column testing at the zinc circuit showed improved zinc selectivity.Scale-up testing was', therefore, conducted on the first zinc cleaner concentrate using the laboratory-size column. The influence of variables such as porous parger grain size, wash water flow rate, airflow rate and froth depth values on column performance was' first assessed. Scale-up parameters were then determined using the optimal operating conditions from the previous tests. Simulation facilitated the determination of the most convenient plant-scale column arrangement.A number of conclusions concerning the experimental determination of scale-up parameters are also presented."

Jan 1, 1993

By Simon B. Blancher, Malo Rousseau, Renato Contessotto, Thomas Wallmach

The Manganese division of the ERAMET group extracts manganese ore in Gabon and produces manganese alloys for the steel industry. ERAMET has an economic interest to maximize the ore throughput without reducing the lifetime of its manganese mines. This can be achieved by means of research and development leading to innovative ore beneficiation processes. For this purpose, the ERAMET research center has designed and constructed a new pilot plant for ore beneficiation by physical separation processes. This pilot facility was erected within an infrastructural and synergetic framework, including competencies in hydrometallurgy, pyrometallurgy, numerical modelling, analyses and mineral characterization that provide ideal research conditions. After laboratory scale tests, a pilot operation of beneficiation of low grade Mn ore (around 35% Mn) was carried out by jigging of the 1-10 mm fraction. This gravity separation process exploits density differences between the various Mn-bearing minerals such as pyrolusite and lithiophorite as well as gangue minerals such as silicates and iron-hydroxides. Enrichment leads to the production of a marketable product associated with a high mass recovery (53% for the jigging step). However, 20% of pyrolusite and 30% of lithiophorite are lost in the waste. Mineral characterization has shown microtextural complexities, but grinding the ore to approach the liberation mesh was not an option due to commercially defined constraints given by the ferro-alloy industry. Recovery of the Mn-bearing minerals or adjustments of the feed grain size (6.3-10 mm) are two potential areas of process improvements identified by means of Qemscan® mineral characterization. This paper details the process tested on a pilot scale (0.5 t/h), which has led to a significant increase in the beneficiation of a low grade Mn ore.

Jan 1, 2016

By A. B. Carino

Gulf Minerals (Canada) Limited's Rabbit Lake uranium operation is located in the northern portion of Saskatchewan, 198 miles southeast of Uranium City and /34 miles northwest of Lynn Lake, Manitoba. The paper follows the ore flow through crushing, grinding, sulphuric acid leaching, countercurrent decantation, solvent extraction, ammonium diuranate precipitation, thickening, drying and tailing neutralization.

Jan 1, 1979

By Lawrence Devon Smith

"The concept of risk is well established in the mining industry. It is acknowledged when estimates of reserves are expressed as proven or probable, when mining and metallurgical recoveries are applied to the ore, and when contingencies are added to costs. However, it is difficult to provide a quantitative assessment of risk. The significant sources of risk in a mineral project and how these are addressed in project evaluations are discussed.The discount rate is examined as a fundamental means of reflecting risk in discounted cash flow evaluations. Current industry practice is discussed, and a methodology for the analysis of risk levels is proposed that assesses the constituent components of the discount rate: real interest, mineral project risks, and country risk.IntroductionThis paper examines the components of the discounted cash flow discount rate and proposes a method of estimating project-specific discount rates. The motivation for this work comes from experience of project evaluations in which owners and purchasers had agreed on virtually every aspect of the evaluation except how much the project was worth. Agreement was reached on reserves, grade, recovery, capital costs, operating costs, taxes, and, by combining these components, even on the final cash flow values. The only difference in opinion concerned the discount rate to be used in the calculation of the net present value. Depending on the life of the project, such differences of opinion can cause a variation of more than 50% in the value placed on a project! This is illustrated in Figure I."

Jan 1, 1995

By K. Hashiba, Y. Z. Liang, K. Fukui, M. Koizumi

"Efficiency and penetration rate during percussive rock drilling significantly affect the speed of tunneling and excavation. Many researchers and engineers have continuously engaged in the advancement of rock drilling performance. Development and modification of the rock drills based on test data are timeconsuming and costly. Hence it is essential to make effective use of numerical simulation. However, most of the numerical models proposed in previous studies were too simple in comparison with the actual percussive rock drilling in which many factors are involved. The objective of our research project is to construct a new realistic numerical model of continuous percussive drilling, which is based on the previous Okubo-Nishimatsu’s model. In this study, the parts of the previous model involved in stress wave propagation and attenuation were modified. The two models were prepared for HD712 hydraulic rock drill mounted on crawler drills and HD210 hydraulic rock drill mounted on drilling jumbos. Stress wave propagation was computed with the discretized one-dimensional wave equation. The calculated results were compared to the stress waves measured on a rod during percussive drilling. In both models for HD712 and HD210, the measured stress waves can be reproduced with the one-dimensional model of the same acoustic impedance as the actual piston, shank rod and rod combined with the CI+spring model as a rod joint. The calculated results indicate that the spring constant in the model of a rod joint needs to be set appropriately depending on drilling conditions. INTRODUCTIONEfficiency and penetration rate during percussive rock drilling significantly affect the speed of tunneling and excavation. Many researchers and engineers have continuously engaged in the advancement of rock drilling performance. Components related to the percussive drilling are a drill body, a piston, a shank rod, rods, rod joints, a bit and rock. The piston in the drill body is reciprocated by hydraulic pressure and collides with the shank rod a few thousand times per minute. Stress waves generated by the collision propagate and attenuate in the rods and rod joints, and then reach the bit. The bit penetrates and crushes rock. During percussive drilling, the components mutually affect each other and self-induced oscillation occurs. The number of blows and the rate of penetration are determined by the practical drilling conditions such as hydraulic pressure, thrust force, number of rods and mechanical properties of rock. Development and modification of the rock drills based on test data are time-consuming and costly. Hence it is essential to make effective use of numerical simulation. However, most of the numerical models proposed in previous studies were too simple in comparison with the actual percussive rock drilling in which many factors are involved."

Jan 1, 2015

By L. K. Nenonen

"Given the properties, locations and quantities of material to be hauled and the dump locations and capacities, the designer wishes to select the type and number of trucks and loading equipment required. Accordingly, software is being developed to assist in creation of the equipment, material and road network data bases, in selection of equipment, materials and road networks from these data bases, and in evaluation of the expected productivities both in a rapid, non-interactive, approximate fashion and a more detailed interactive fashion which permits the user to act as superintendent, if he so chooses. The basic technology has been developed and applied to an open-pit copper mine and is being refined and generalized for oil sands and coal mining applications.BackgroundA set of mathematical and interactive computer models are under development to aid in the selection of equipment and operating policies for an open-pit oil sands mine being planned by Canstar Oil Sands Ltd. This paper describes the computer models being developed of truck haulage systems. Although the interactive truck haulage model is based primarily on a model developed by the National Research Council in collaboration with Glenayre Electronics Ltd. of North Vancouver and Lornex Mines Limited(2).(3l, substantial changes and improvements are being incorporated to greatly increase its generality re equipment types, road network characteristics, dispatching and supervisory policies, etc. Although this paper is principally devoted to the truck haulage model, discussion is included concerning its interactions with other models."

Jan 1, 1982

By R. J. Mitchell

"The use of hydraulically delivered classified tailings sands to provide ground support in large mining operations is still widespread despite recent developments of alternate backfilling methods and materials. The major disadvantages of the use of hydraulic fill are the costs and risks associated with slurry delivery. The main risk is that of bulkhead failure resulting from sand liquefaction due to insufficient operational control or due to dynamic loading from earthquake or rockburst. That risk may be eliminated by the pouring of a stiff cemented sand plug in the base of each stope prior to continuous fill pouring in that stope. An additional advantage of cemented plugs is that massive bulkheads are not needed. Instead, a temporary (removable and reusable) bulkhead can be used for plug forming.Physical model studies of fill pressures on a temporary bulkhead were carried out in a 3 m radius centrifuge facility. Fill pouring in-flight was carried out in order to model prototype stress paths. The results indicate that the average bulkhead pressure is likely to be less than 10 kPa under normal operating conditions and less than 20 kPa under the poorest anticipated operating conditions which include smooth walls, high slimes content and high water-content slurries. A portable bulkhead consisting of a central core and a surrounding sealing bladder was modelled and found to be effective. The use of different sizes of cores allowed the stress distribution adjacent to these bulkheads to be evaluated."

Jan 1, 1992