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By W. Petruk, D. R. Morris

"The lead concentrate produced from the volcanogenic base metal ore of Brunswick Mining and Smelting in New Brunswick contains major to trace amounts of iron, zinc, cadmium, arsenic, antimony, copper, silver, selenium, tellurium, bismuth, sulphur, tin, indium, mercury and manganese as impurities. When the concentrate is sintered some of these impurities enter a variety of oxide phases, whereas others precipitate as metals. In the lead blast furnace the oxide phases decompose and the impurities recombine 10 form new phases, most are eventually discharged to the slag. The metals of the sinter remain as metals in the lead blast furnace where even more are produced, and are discharged largely with the lead bullion,IntroductionMany lead concentrates are produced from volcanogenic base metal ores . Such ores contain a wide variety of trace minerals and trace elements , therefore, concentrate s obtained from them will contain the trace elements as impurities . The impurities in the lead concentrate from one such ore, the Brunswick No. 12 deposit of Brunswick Mining and Smelting Corporation (BM S) in the Bathurst area in New Brunswick , were studied as pan of a larger investigation that was conducted to determine the extent of chemical reactions of the sinter within the lead blast furnace(1,2) The lead concentrate was investigated to identify the host mineral s for the impurities, the lead sinter was studied to identify the host phases, and frozen products from different depths within the BMS blast furnace at Belledune, New Brunswick were studied to determine the behaviour of the impurities.T he investigation was performed by pre pa ring polished sections o f the samples and studying them with a reflecting microscope, a scanning electron microscope (SE M) equipped with a Kevex energy dispersive X-ra y analysis system, a microprobe, and a Quantimet 720 image analyzer. The samples were also analyzed by X-ray diffractometer, and individual grains were analyzed by the Debye-Scherrer X-ray powder film method."

Jan 1, 1985

By J. Stachulak, M. Scobie

"This paper addresses the occurrence and indicated causes of conveyor fires in North American and European underground mines. Some significant convey or fires which have been experienced in recent years in Canadian hardrock mines are then reviewed. The nature of existing conveyor monitoring technology is considered in the context of such fire hazards. Experiences with new monitoring technology recently installed at several conveyor sites at Inca Ltd. mines are then reviewed.IntroductionFires associated with conveyors have long been recognized as a serious hazard in underground coal mines. Recently, however, there have been some significant conveyor fires in Canadian underground hardrock mines. These offer important evidence as to the nature and causes of potential hardrock mine fifes. They also warrant attention with a view to improving over-all mine design, ventilation and emergency preparedness.In addition, a new era in mine communications and monitoring technology has been entered which should offer improved capability to protect against such fires. This paper was motivated by the need to understand the causes and mechanisms of conveyor fires in order to improve their safety. This should be possible through implementing more effective monitoring systems, as well as improving conveyor design. Underground mines are becoming more intensively mechanized, with less human surveillance of equipment and a greater dependency on remote monitoring systems."

Jan 1, 1992

By I. R. Muirhead

"One approach to making new technology available is to demonstrate its value under full-scale operating conditions. Studies were undertaken to assess the feasibility of this approach to introducing a longwall mining system to the western Canadian coalfields.The longwall method of mining coal is described, world and Canadian usage is reviewed, and the merits of the system in comparison 10 other coal mining methods are discussed.The rationale for a longwall demonstration in western Canada is presented, along with a proposed organization for the design, operation and dissemination of the findings from such a trial. The factors which must be considered in the design of the demonstration, and in the assessment of a potential site are highlighted. It is concluded that a demonstration of this technology is both timely and essential to prepare the way for the western Canadian coal industry of future prospects for coal.IntroductionFor many years CANMET has encouraged research work organized on a cooperative basis. This requires that a working consensus must be negotiated by researchers and operators at the beginning of the project and continuously refined as work proceeds. The result is usually a more relevant selection of research problems, improved direct ion and con duct of experiment al work and often a validation phase in which research concepts are tested in an opera ting environment. All this tends to narrow the gap between obtaining research results and applying them.Even under the best of circumstances cooperative projects require a good deal of coordination and enthusiasm to maintain focus and the pace of work. The working perspective of a research scientist in a government laboratory is substantially different from that of a mine operator at a producing mine, and a common ground must be found. This is difficult to do and cooperative projects typically evolve over several years as experimental results progressively define the potential solutions to mining problems."

Jan 1, 1985

By L. C. Galloway, G. L. Tiley

"Mine hoist brakes must meet the following statutory performance criteria:- There should be two independent braking systems; at least one should act directly on the hoist drum.-If one brake fail s, the others should be able to retard and stop the hoist safely before the descending conveyance, carrying the rated load, reaches any obstruction.- When all brakes apply, decelerations should not be so violent that men travelling in the conveyance are injured.- The brakes shall not overheat and fade during an emergency stop.This paper discusses design principles and capacities of caliper and disc type brakes, when applied to double drum and friction hoists of equivalent capacity.IntroductionThis paper is about the brakes that are used on mine hoists; their functions, especially in emergencies, typical design, and how they are operated, controlled, tested, and adjusted.There are two basic types of mine hoists:1. Drum hoists, where the ropes are attached to, and coil on drums. The simplest system has only one drum. Most such hoists, however, have two drums, attached to a common shaft. Ropes are wound on each drum in opposite directions, so that when one conveyance is being raised, the other is lowered. The conveynaces may travel in vertical or inclined shafts. In the latter case, the hoist s are referred to as slope hoists.2. Friction hoist s, where the headropes are not attached to the wheel, but are in contact with it for an angle of lap of, typically, between 180 and 195 degree s. Forces are transmitted from the hoist wheel to the head ropes by friction.The lower ends of the conveyances are connected to balance ropes , approximately the same weight per foot as the headropes."

Jan 1, 1986

By B. J. Fryer, R. P. Taylor

"As a monitor of the processes involved in the formation of granitoid mineral deposits the coherent group behaviour of the rare earth elements (REE) actively reflects changing fluid characteristics. For example, in the porphyry environment, magmatic-hydrothermal fluids produce potassic alteration with strong enrichment in the light rare earth element s (LREE), reflecting their high pH, low fluid/rock ratios, and the dominant role of CI- complexing in metal (i.e. Cu, Au) transport. With increasing fluid/rock ratios and decreasing pH accompanying the progressive involvement of meteoric fluids (and the production of propylitic, argillic, and phyllic alteration) anionic species such as F - and CO, 2- become important in metal (e.g. Mo, W,) transport through complexing, and their activity in the hydro thermal fluids is illustrated by mobilization of the heavy rare earth elements (HREE).The relative involvement of CI- versus F - versus CO32- in metal transport in other granite-related systems can also be monitored through REE behaviour. Hence granitoid tin-tungsten mineralization and associated greisenization typically exhibit heavy rare earth enrichment and evidence the importance of F' and CO32- in metal transport. Similarly, heavy rare earth element enrichment in hydrothermal uranium deposits can be related to the transport of uranium as carbonate complexes. REE are widely accepted as powerful tools in the study of rock petrogenesis, but their use has been neglected in the investigation of mineral deposits. The recognition of the systematic variation of REE distributions in granitoid mineral deposits suggests that the application of REE geo chemistry, particularly when integrated with fluid inclusion and isotope studies, can provide (1) an effective method for identifying the physicochemical controls of metal transport and (2) a useful criterion for elucidating metal distribution."

Jan 1, 1983

By Jian Deng, Haitian Sun, Zengqian Hou, Shuhe Song

"Abstract - Volcanogenic massive sulfide (VMS) deposits, an important base-metal deposit type in China, occur widely in submarine volcanic districts of variable magmatic affinities. These VMS deposits range in age from Archean to Mesozoic, but most are in Proterozoic and Paleozoic sequences. More than 60% of VMS deposits formed in the Paleozoic, the most important metallogenic eon. Three important Paleozoic VMS-metallogenic provinces include Northern Qilian, Sanjiang and Altai provinces. The Proterozoic constitutes the next important era, but with no VMS deposits in the middle Proterozoic. VMS deposits associated with the Proterozoic volcanic rocks occur around the Yangtze Platform and in the western Kunlun-Qinling. The Triassic is third in importance, with VMS deposits concentrated in the Sanjiang Tethys. The Archean has only one VMS deposit, on the northern margin of the Sino-Korea Platform.Five distinct compositional classes of Chinese VMS deposits have been distinguished: Cu, Cu- Zn (or Zn-Cu), Cu-Fe, Zn-Pb-Cu, and Pb-Zn (-Cu). The Cu, Cu-Co, and Cu-Zn types of deposits occur sporadically from the Archean to Paleozoic, and are closely associated with mafic and ultramafic volcanic sequences. The Zn-Pb-Cu and some Cu-Zn type deposits are restricted to the Paleozoic and Triassic, and are hosted by calc-alkaline felsic rocks in bimodal basalt-rhyolite sequences, whereas Cu-Fe and Pb-Zn type (except for the Laochang deposit) deposits are restricted to the Proterozoic and occur in calc-alkaline volcanic sequences. As large quantities of marine mafic volcanic rocks were deposited in western China, Cu and Cu-Zn deposits are major types of Chinese VMS deposits.Chinese VMS deposits formed in a wide range of paleo-tectonic settings and depositional environments, such as island-arcs, rifts, aulacogens, and ocean ridge hot spots. Among these, the rift and back-arc environments are the most important, containing about 60% of Chinese VMS deposits. Aulacogens are a subordinate environment where most of the Proterozoic VMS deposits formed. The oceanic ridge and hot-spot systems are common in the tectono-magmatic domains in China, but contain only a few small Cu and Cu-Zn type VMS deposits.The Chinese VMS deposits have usually been influenced by both deformation and metamorphism to various degrees, resulting in changes in the shape and metal distribution. Seven representative deposit styles have been recognized: sheets, sheet plus strata-bound stringer, cyclically zoned deposits, mounds, mound-like deposits, strata-bound stringer-disseminated, and stockwork-disseminated deposits. The formation of these various styles of deposits is controlled by several key factors, such as lithology and permeability of the host rocks, focused or unfocused discharge, temperature and chemical composition (e.g., salinity) of hydrothermal fluids, as well as depth of seawater."

Jan 1, 1999

By Ros Taplin

Realizing the potential of cutting greenhouse gases (GHGs) associated with mining, a variety of approaches has been proposed for their mitigation. The Clean Development Mechanism (CDM) under the Kyoto Protocol to the UN Framework Convention on Climate Change (UNFCCC) has been a key mechanism to assist in implementation of mitigation measures. The objectives of CDM are not only to assist Annex I countries in meeting their GHG emissions reduction targets with cost-effective reduction but also to achieve sustainable development in non-Annex I countries. However, apart from China, India, Brazil and Mexico, many developing countries are still in the stages of formulation or realizing CDM strategies. Projects associated with methane capture and flaring are the fourth most prevalent type of CDM project internationally. This research primarily has addressed emissions abatement and sustainable development aims and effectiveness of registered CDM projects associated with coal mining in China. The paper reviews 30 currently registered CDM projects in China on the UNFCCC database and six other non- Chinese projects. Systematic evaluation involving content analysis of documentary evidence regarding coal mining CDM projects is presented in relation to firstly, quantitative reduction of GHG emissions and secondly, sustainable development outcomes. The projects have been assessed via a set sustainability criteria. Overall it was found that sustainable development goals are only briefly referred to in Project Design Documents, Letter of Approvals and validation documents. Varying types of sustainability initiatives have been implemented with weak to strong indications of effectiveness. This has implications for the future effectiveness of CDM projects in the mining sector, the proposed new market mechanism under UNFCCC, and for assessment of projects under mechanisms established outside the UNFCCC.

Aug 1, 2013

By Michael S. Moats, Addin Pranowo, Gerardo R. F. Alvear F., Nigel Aslin

The toxicity of arsenic is well known and documented. However, the presence of arsenic in copper electrorefining anodes and electrolyte is critically necessary to produce high quality cathode. Arsenic as well as antimony and bismuth concentrations vary depending on their relative concentration in the anode copper received from the smelter. This paper will discuss the behaviour and benefits of arsenic in copper electrorefining and the detrimental effects of antimony and bismuth on cathode quality and tankhouse performance. This will include the minimization and mitigation of problems associated with arsenic, antimony and bismuth including cathode contamination, floating slimes, scaling and anode passivation.

Jan 1, 2014

By J. P. Rajot, H. Mouzannar, M. Bost

"The design of rock foundations may need to evaluate shear strength of rock-concrete interface by performing laboratory direct shear tests. A series of tests were carried out on specimens for different values of the spacing free of encapsulating material about the shear plane and different values of normal stress. Different kinds of failure were observed and not necessarily at the rock-concrete interface. The spacing free of encapsulating material appeared to be of significant influence on the test results. A mechanical analysis is presented which illustrate the influence of the loading conditions in the direct shear box on the failure mechanism. INTRODUCTIONThe design of rock foundations subjected to significant lateral loads requires defining the value of the shear strength of the interface between rock and cast in place concrete. Verifying the stability against sliding of strip footings subjected to inclined loads (SETRA, 2009) or concrete gravity dams (CFBR, 2013) are common examples where design modelling approaches imply the shear strength, sometimes the deformation behavior, of the rock-concrete interface, more or less assumed as a failure plane.Defining the behavior of rock-concrete interfaces relates to tribology. Many studies have been conducted to improve the representation of this behavior (e.g., Johnston & Lam, 1989; Kodikara & Johnston, 1994; Gu, Seidel & Haberfield, 2003; Saiang, Malmgren & Nordlund , 2005; Fishman, 2008; Eltervaag, 2013; Gutierrez, 2013), raising many questions. The behavior appeared to be influenced by many factors such as the geometry of the interface which is not planar, the roughness of the natural rock, the rock mineralogy and the concrete formulation. In addition, the study of the shear strength of rock-concrete interfaces involves considering the two different deformation behaviors of both rock and concrete. Finally, the observed failure mechanism is strongly influenced by the initial cohesion due to adhesion between the two materials when concrete is directly cast onto rock."

Jan 1, 2015

By Neal Harries

Ground movement is normal in open cut mining operations, mainly caused by excavation response and blasting. Movement of the ground can be acceptable provided it is not unexpected and catastrophic. However, in steep mine walls and the very large open pits being developed today the consequence of slope collapse can be catastrophic. Such risks can be minimized at the planning stage by reducing slope angles, but this carries a very high cost. Also, instabilities which develop whilst mining can lead to ore reserves being quarantined, which represent a high cost to the mining operation. In spite of such safety measures, unexpected failures have occurred in the past. These issues motivated the development and production of the slope stability radar (SSR). There are currently over 80 GroundProbe SSR systems deployed in metalliferous and coal mines in 17 countries. The unexpected failure of rock walls at mining sites is a major cause of death and serious injury. Slope failure is also one of the major causes of economic and production losses. An unexpected wall failure can bury critical equipment. It also disrupts the mine plan. It is common to cease mining for several days or weeks following a wall collapse due to uncertainty over stability. Direct economic losses in remediation alone can easily exceed $1,000,000 per incident. The economic costs of injury or fatality are much higher including closure of mines during the incident investigation process. Massive wall failure can result in direct and indirect costs measured in millions of dollars. This paper will present some recent case studies of the SSR operation in open cut mines in North America, including Thompson Creek Mining Company (Idaho), Smoky Canyon Mine (Idaho), and a general case study on extreme cold weather use of the SSR.

May 1, 2009

By Q. Han, W. Dai

Al-Ti-B type master alloys have been widely used in the grain refinement of aluminum since 1940s. The introduction of Al3Ti and TiB2(AlB2) particles reduces the grain sizes down to about 200 micrometer level and makes cold work possible. However, the mechanism for the grain refinement is still not clear, though it is believed that TiB2 in the presence of Al3Ti nucleate a-Al grains in solidification. This paper presents our finding on the formation of (Ti,Al)B2 solid solution, which leads to a proposed theory on grain refinement by Al-Ti-B type master alloys that upon addition into aluminum melt stable TiB2 particles react with aluminum slowly and release titanium into the melt. The titanium thus released in combination with titanium in the melt through dissolution of Al3Ti maintains a transient titanium-rich layer on the surface of (Ti,Al)B2. This layer offers a low crystal mismatch with a- Al and promotes the nucleation of aluminum grains.

Jan 1, 2014

By K. Tsuchihashi, A. Kishimoto, T. Uda, Y. Kado, S. Maruyama

We recently proposed a continuous production process for titanium metal with some experimental results. In the process, titanium tetrachloride is reduced by Mg in the presences of Bi to form a Bi-Ti alloy at 900ºC. At this temperature, the obtained alloy is liquid and allows for the continuous removal of product and heat from the reaction vessel. The obtained Bi-Ti alloy was vacuum-distilled at 1000ºC for 24 hr, and 98 at % (92 wt %) titanium, which was easily crashed to powder, was obtained. Bi solvent was selected because of the highest titanium solubility at 900ºC and the moderate vapor pressure among the candidate metals (Bi, Sn, Pb, Zn, and Sb).

Jan 1, 2014

By T. P. Riordon

"Major swings in the silver price since 1979, along with the ever constant fight to maintain ore reserves has forced United Keno Hill Mines Limited through several unique series of events in order to survive in the 80s.This paper is specifically meant to be a description of safety and productivity improvements achieved to ensure the survival of a silver mining community ill the Yukon. There are, however, other events and conditions that must be described to complete the story and this paper attempts to do that as well IntroductionUnited Keno Hill Mines Limited, a subsidiary of Falconbridge Limited, is the only silver producer in the Yukon. Operations are located in north central Yukon, in and around the small town of Elsa, latitude 62.5 °, about 275 road miles from Whitehorse. The Arctic Circle is about 185 miles due north of the town.Temperatures in 1986 ranged from a high of 28.5°C in July to a low of -37.0°C in November, however, much lower temperatures have been recorded in previous years. Due to the mountainous terrain the town of Elsa is completely in the shade from mid-November until early February, a period of about 12 weeks.The Elsa area, as is most of the north, is considered semiarid with an average precipitation level of about 15 inches. Vegetation, however, is quite abundant though slightly dwarfed at the townsite elevation of 3200 feet above sea level: Many of our operating and exploration portals as well as our open pits are above the tree line. Permafrost in the area has been recorded up to 400 feet below the surface."

Jan 1, 1988

By Lesley Hymers

First Nations Natural Resources Youth Employment Program PDAC Mining Matters ? Charitable organization ? Provide education to students, teachers, and the public about rocks, minerals, metals, and mining ? Provide current information and offer exceptional educational resources that meet provincial Earth science and geography curriculum expectations First Nations Natural Resources Youth Employment Program ? Provide instructional development workshops for educators who are teaching Earth science and geography ? Since 1994, reached more than 400,000 students, teachers, industry representatives, and members of the public

May 1, 2009

By Robert D. Brown

"All ten Canadian provinces have now tabled their 1981 /82 budgets . Only the provinces of Ontario, Quebec and British Columbia made more than minor modifications to their tax structures, with both Ontario and Quebec imposing major tax increases. In the past year, the federal budget was also released in the spring. Not so this year: we have that to look forward to in the fall!This month, Tax Notes presents a brief summary of the more significant tax changes introduced at the provinciallevels in the last months.Summary of provincial tax rate changesThe tax changes in this year's provincial budgets were both up and down- but there were far more tax increases than tax cuts.At the corporate tax level, two provinces, New Brunswick and British Columbia, increased their general corporate income tax rate; the former by two percentage points and the latter by one percentage point. Quebec, rather unexpectedly, sharply cut its corporate tax rate on business income, but increased some of its other business taxes at the same time. British Columbia reduced its corporate tax rate on small business income by two percentage points and Saskatchewan by one percentage point."

Jan 1, 1981

By A. P. E. Dirige

In order to maximize the recovery of ore and to save on costs in undercut mining, backfill of low cement content is used to fill the mined out excavations. This backfill mass is supported by a sillmat structure cast from cemented backfill of very high strength. The stability design of sillmats must be carefully studied to provide very effective, safe and economic mining operations. This paper presents a methodology and procedures for sillmat design based on three engineering modeling approaches: analytical, numerical and centrifuge modeling. Application of the design approach is demonstrated from a design study conducted for an underground gold mine, aimed at minimizing backfill binder content and at producing cost efficient paste fill recipes for sillmat construction. Application of the engineering design recommendations was projected to result in substantial annual cost savings to the mine operation.

May 1, 2007

By John H. Fowler

"Barytes is one of the major components of drilling fluids used in oil and gas well-drilling. This mineral's close association with the petroleum industry bestows it with a commodity status not enjoyed by many other industrial minerals. Approximately 85% of world barytes production is used as a weighting agent in oil and gas well drilling while the remaining 15% is consumed mainly in the manufacture of barium chemicals, glass and as a pigment, filler or extender.Barytes mining began in Nova Scotia around 1865 and has continued until the present. Currently there are three barytes producers in the province one exporting pharmaceutical-grade barium sulphate and the other two supplying drilling mud-grade barytes to the offshore. Several barytes exploration and development programs are underway with excellent possibilities that Nova Scotia deposits will supply a significantly larger share of the drilling mud-grade barytes used in east coast drilling programs.Currently there is renewed interest in barytes activities in Nova Scotia because of its use as a weighting agent in drilling flu ids used in offshore oil and gas drilling programs.This paper reviews the use of barytes by the well drilling industry; outlines the history of barytes mining in the province, progressing to present-day exploration, development and production activities underway in Nova Scotia; and concludes with the market potential for Nova Scotia barytes."

Jan 1, 1986

By Yuki Tsunazawa, Sho Fukui, Chiharu Tokoro

"A milling process is one of the important unit processes in mineral processing. In the milling process, the control of particle size distribution is necessary for the later physical separation process. Since the milling process is strongly affected by the equipment designs, operation conditions and raw materials, the control for particle size distribution of milling products is mainly based on empirical rules. Recently, the discrete element method (DEM) has been widely used as an effective tool to investigate the behavior of grinding media. Although the behavior of grinding media can be accurately simulated, it is not well-established the way to predict particle size distribution after milling by the DEM simulation.The objective of this study was to develop a new method to predict particle size distribution in ball milling using the DEM simulation. To predict particle size reduction, a correlation between experiments and the simulation was investigated in various operation conditions, that is, wide range of the rotation speed and the filling ratio of grinding media. In experiments, after lime stone was ground, the average and variance of particle size distribution were evaluated using some kinds of distribution equations. In the DEM simulation, direct simulation of particle disintegration in milling process is generally very difficult because of huge computational load. Therefore, collision energy between grinding media balls orgrinding media ball and wall was used as a factor of particle disintegration.As a result, a good correlation between experiments and simulation was obtained. In addition, the particle size distribution in ball milling could be predicted using this correlation. Therefore, these results indicated that the use of the correlation between experiments and the DEM simulation was an effective approach of predicting the particle size distribution in milling process."

Jan 1, 2016

By Michel Dagbert

"This paper illustrates the different ways grade-tonnage curves can be generated f or a mineral deposit. It emphasizes systematic discrepancies between reality, estimates and actual production according to different estimation methods and grade control programs. It does not offer a universal solution to the prediction of grade-tonnage curves. Hopefully, it will inspire caution to mineral economists who use estimated grade and tonnage data in the establishment of an optimum cut-off grade for a mining operation.IntroductionThe value of a mineral development venture often depends on a grade-tonnage curve. Statistics can help. The idea is to divide mentally the orebody into small blocks called selective mining units or SMUs. A SMU is an idealized version of the quantity of rock the grade of which will be tested against the cut-off at the time of mining. It could be as small as a truck load or a shovel load in very selective operations like some uranium mines where radiometric probing of each truck or car is performed. More typically, in an open pit operation, it will be the smallest zone flagged as ore from blast hole data, e.g. a 5 m by 5 m by 10m block, if blast holes are on a 5 m grid and bench height is 10m. Having defined the SMUs, the grade-tonnage curve determination amounts to evaluating the grade distribution of all the SMUs that can be mined in the depo sit. If we know this distribution we simply apply the cut-off to it and we get the number of SMUs above the cut-off (i.e. ore tonnage) and their average grade. .Assessment of the grade distribution of SMUs from exploration drill hole data is not an easy exercise and much has been published on the subject (David, 1972; Marechal , 1972; Huijbregts, 1975; Marechal, 1975; Guibal and Touffait, 1982). In this paper, we use a gold mine example to illustrate the influence of SMU size on the results. With the same example we also show that ""common-sense"" methods of grade-tonnage curve determination can sometimes be misleading."

Jan 1, 1987

By P. Venkatasubramanian

"In recent years, computer based ""expert systems"" have been taking on large complex tasks for which no exact algorithmic solutions are feasible; tasks previously reserved for human experts requiring empirical knowledge, judgment, experience, developing a ""best solution "" by the use of plausible reasoning. Mining method selection is an appropriate area for the application of an expert system because extensive and detailed knowledge is required to make a ""best"" interpretaion of frequently ambiguous geological information. The expert system model presented here would enable users to apply expert knowledge to the evaluation of methods for coal deposits mineable by underground methods. IntroductionIn an increasingly complex and specialized world, human expertise spanning scientific, economic, social and political issues plays an increasingly important role in all branches of engineering. This is especially true of mining engineering. The number of scientific and professional disciplines involved in mine planning and evaluation, illustrates the problem. A conservative list includes geology, geophysics, geotechnics, hydrology, mining, environment, and economics.Engineers are almost obliged to be experts in at least one of the above disciplines if they are to handle the volume of information required in the planning process. Although computers have become indispensable tools in many endeavours, there is continued reliance on the human expert's ability to identify and synthesize these diverse factors, to form judgments, evaluate alternatives , and make decisions . This is especially true with regard to problems that are not easily amenable to precise formulations.The precious resource of human expert is also fragile and transient. The departure of a crucial expert from an organization ma y cause serious dislocations. Senior experienced people impart their knowledge of younger colleagues, but the demand for their talent may not leave sufficient time for such educational efforts. In recent years, computer based "" expert systems"" have been taking on large complex tasks for which no exact algorithmic solutions are feasible; tasks previously reserved for human experts, requiring empirical knowledge, judgment , experience, developing a ""best solution"" by the use of plausible reasoning."

Jan 1, 1988