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By F. Hampshire

"IntroductionThis paper is intended to cover questions raised by operating staff at various installations and is not intended to give comprehensive coverage of power plant and power system design. The paper is concerned mainly with the electrics , although a brief section gives the reasons for selection of diesels rather than other prime movers.The material is not new but brings out points which seem to be raised regularly during the design , commissioning and operation o f a new plant. Diesels versus other Prime MoversDiesel-electric plant for the mining industry falls into two major categories -emergency power and prim e power.1) Emergency power (for use only when the regular utility supply has failed) requires reliable starting and operation and reasonable first cost. Fuel economy and maintenance are of little importance as the machine(s) generate few kilowatt hours only. The diesel's competition in this field is the gas turbine, however diesels are more widely used than gas turbines in this application.2) Prime power is a different situation as the bottom line of total cost is highly affected by fuel costs.In general , mines which are within reasonable transmission distance of an existing utility find the lowest net cost result s from hooking up to the utility. If a min e is remote from an electric utility then the possible alternatives are:a) Hydro- electric power if there is a site capable of development at reasonable cost including the cost of transmission facilities. Such sites are not common, but brief and inexpensive considerationof this possibility is warranted .b) Diesel power with consideration of different grades of fuel.c) Thermal (steam) power generation from coal or oil.d) Gas turbines.In addition to the above there is the possibility of wind power (as a supplementary source) and a number of technologies which may become feasible in the future (e.g. small nuclear plants, fuel cells). For obvious reasons, small isolated generating systems required for remote mines, tend to lean to conservative technology.Among the fossil fuel plants, the diesel enjoys advantage on over-all costs as summarized in Table 1."

Jan 1, 1986

By James J. Scott

"In the two years since their introduction, Friction Rock Stabilizershave replaced40 per cent of the previously used fixtures in the metal and non-metal mines in the United States. The Friction Rock Stabilizer, or ""Split Set "" , is a mechanical rock stabilizing system which uses friction to prevent rock movement . The Split Set is a tapered, rolled, steel tube that is slotted along its length. As it is driven into a drilled hole smaller than its diameter, it compresses, pre-loading the surrounding rock. This paper discusses the uses and acceptance of the friction rock stabilizer in mines in the United States. IntroductionFriction Rock Stabilizers, commonly called Split Set™· Stabilizers, have been under development by the author and Ingersoll-Rand Company since early 1973. Five years of intensive laboratory and field testing led to their introduction to the metal mines in the United States in the fall of 1976. Actual sales started in February of 1977and, to date, over five million units have been marketed to metal mines. The present rate of usage is near 3 V2 million units per year, which is approximately 50070 of all roof fixtures used in the United States metal mining industry,Richard Hoppe, senior editor of Engineering & Mining Journal. , in an article in the February 1979 issue entitled ""Winning the Battle Against Bad Ground"", said: ""In hardrock mining operations in the western U.S., particularly underground uranium mines where exceedingly difficult ground is common, no roof support system has been accepted more quickly than the Split Set friction bolt invented by Dr. James J . Scott and developed by Ingersoll-Rand Co."" This paper describes how Friction Rock Stabilizers function and presents technical data to show the uniqueness of such systems."

Jan 1, 1980

By Piotr Malkowski

Studies on the properties of rocks heated to high temperatures are rather rare. Such research is occasionally conducted for example; in areas around nuclear power plants. The national Polish coal gasification (underground coal gasification, or UCG) project has, however, forced the analysis of the geomechanical properties of heated rocks in the vicinity of a designed geo-reactor. Ukrainian experience with UCG show that rocks up to 2 m from the burned coal seam be at a temperature > 600ºC. Such a high temperature will undoubtedly influence their physical properties. This paper presents studies on the strength and deformation properties of carboniferous rocks in the Upper Silesian region, where the UCG process is planned. Three types of rocks were tested: claystones, mudstones and sandstones. Laboratory tests of these rocks evaluated compressive strength, elastic modulus and weight loss. An evaluation of the results of the tests comparing the thermal conductivity of rocks and their specific thermal capacity was then carried out. All of the rocks studied were heated to 300, 600 and 1000ºC, and also evaluated at room temperature. This procedure shed new light upon the behavior of heated rocks in relation to their distance from the designed geo-reactor. The test results presented were developed within Research Task No. 3 ?Developing a technology of coal gasification for efficient production of fuels and electric power?, financed by The National Centre for Research and Development under strategic research and development programme ?Advanced Technologies for Energy Generation.?

Aug 1, 2013

By Peter A. Amelunxen, Richard LaDouceur, Courtney A. Young

"Many of the rare earth elements, the lanthanide series on the periodic table, are on the U.S. Department of Defense Strategic and Critical Materials list. In this regard, the U.S. Army Research Laboratory (ARL) has funded several projects at Montana Tech focusing on rare earth element recovery from natural resources. Current froth flotation operations utilize octyl hydroxamate for rare earth mineral extraction, however recovery is not ideal and flotation performance can be improved. Salicylhydroxamic acid (C7H7NO3) was identified as a novel collector due to similarities with n-octyl hydroxamate, notably the amine head group. Salicylhydroxamic acid is primarily used in the medical industry but due to the amine head group is ideally suited as a collector for rare earth mineral flotation.Parametric studies were performed for the flotation of rare earth minerals by modifying a wide range of variables. Mechanical variables of a 6L bench scale flotation cell, such as air inlet flow, rotor speed, and milling time for liberation were modified to elucidate energy input parameters for the desired minerals. Chemical parameters such as collector concentration and pH were varied to understand solution chemistry considerations of the salicylhydroxamic-rare earth mineral system. The study obtained a statistically significant experimental model for the flotation of rare earth minerals. A two stage compartmental model was also utilized for the determination of the first order flotation rate constants for each mineral. Optimized recovery of rare earth minerals was found to occur at near neutral pH ranges using salicylhydroxamic acid with maximum recoveries approaching ideal industrial standards although rare earth mineral grades were still not sufficient.INTRODUCTIONRare earth elements (REEs) are found in minerals that contain several REE which makes costeffective separation of the rare earths difficult. Significant scientific challenges have hindered mineral separation. The molecular similarity of rare earth elements results in minerals containing several REEs, such as bastnaesite [(Ce, La) CO3F]. This prevents efficient separation during concentration steps, for instance flotation, and has a direct impact on successive metallurgical processes. Consequently, concentration during flotation is of rare earth minerals (REM) as opposed to REE."

Jan 1, 2016

?Podolsky Water treatment plant discharges to Norman North bog which drains into Whistle / Post Creek watershed and into Wanapitei Lake ?Whistle Mine closed and reclaimed but continues to treat and discharge water to Whistle Creek

May 1, 2009

By F. Kitzinger

Electromagnetic testing of wire rope has become more and more reliable over the past two decades. This improvement is partly a result of an unprecedented progress of electronic technology, which permitted the development of a new breed of testing instruments. There are two basic methods for the electromagnetic testing of wire ropes, the AC method and the DC method. Both methods rely on magnetic field disturbance caused by mechanical anomalies in the rope structure. The wire rope under test is passed through a magnetic excitation field, which can be a weak alternating field or a strong static field. Because the alternating field is produced by an alternating current, these instruments are of the AC type(l). In the early days of ND-testing, strong permanent magnets were not yet available; therefore, the static magnetic field was produced electromagnetically with direct current. Instruments based on static excitation are still called DC instruments(2), even though the field is now produced by a permanent magnet. Both these methods have certain characteristic features. The AC method can detect loss of metallic area caused by corrosion or other effects, whereas localized faults such as broken wires are better detected by the DC instruments . The basic principles of the wire rope testers have remained unchanged over the years and the improvements present in the new instruments usually reside in the signal processing and recording sections. The Instrumentation Department of the Noranda Research Centre* has been involved in a four-year development program which resulted in a new type of wire rope tester, the Magnographv** . This new instrument in many ways represents a considerable departure from the traditional wire rope testers. The Magnograph has already been patented in Canada and the U.S.A.(3), and patent applications are pending in other countries.

Jan 1, 1979

By A. M. Girodo

"Dorbyl Heavy Engineering has been manufacturing winders since 1949 mostly for the South African mining industry.Table 1 shows that the vast majority of winders have been double drum winders. At the greater depths with larger ropes being employed, it became apparent that multi-rope winders would be needed. The high stress variation in Koepe winder ropes at great depths especially beyond 2000 m, ruled out this possibility. Thus the original concept was borne for the Blair multi-rope winder where the stress level variations in the rope would be as per the well known, tried and tested double drum winder. The Blair multi-rope was also devised to increase payload by using multiple ropes.With the increasing costs of transporting men and material coupled with fact that orebodies are getting deeper, various feasibility studies have been carried out by South African mining houses. For this reason Dorbyl Heavy Engineering has done conceptual design work of both double drum and Blair multi-rope winders with diameters up to 8.5 m dia (still well within our manufacturing capabilities). These feasibility studies have looked at depths approaching 4000 m*.This paper covers the typical duties leading to the choice of single drum, double drum, Koepe and Blair multi-rope hoists on South African gold mines. A brief synopsis of Dorbyl hoists in use in the South African mining industry, with some indications of future trends, will be discussed.With current installed depths of wind approaching 2500 m, the Blair multi-rope hoist has been used extensively for the heavier payloads.Some of the main considerations pertinent to the design of the Blair multi-rope hoist are illustrated together with the implications of using this type of hoist to winding depths of3000 m to 4000 m in the foreseeable future."

Jan 1, 1995

By K R. Brentley

"Tshepong Mine, Harmony’s largest gold producing mine, is situated in the Free State portion of the Witwatersrand Basin, east of Odendaalsrus and north of Welkom, South Africa. The Basal reef is a narrow tabular conglomerate and is the main gold bearing ore body. The strata strikes mainly in a northsouth direction with an average dip of 22 degrees. Currently mining takes place at depths of between 1 690m and 2 150m below surface. The Basal reef unit consists of a conglomerate ranging between a few and 30cm in thickness. Some 80-90% of the gold occurs in the lower portion of the conglomerate. Directly above the conglomerate is a quartzite placer unit, the Basal quartzite, which is a clean, hard competent rock and varies in thickness between 50cm and 200cm. The Basal unit is overlain by the Khaki shale which can vary between 30cm and 500cm in width. It is weak and incompetent khaki coloured chloritic shale.A method of stoping, termed “undercut”, is practiced in order to remove the lower 15-20cm of the gold rich strata. The method entails removing this portion along with some 70-80cm of footwall host rock which is a strong competent quartzite. The hard competent quartzite overlying the conglomerate is left in-situ to form a competent hangingwall which can stabilize and prevent exposure of the weak Khakishale. This method of extraction was developed through trial and error and has been used reasonably successfully since its inception in the early 1960’s where the method was developed to extract the Basal reef at the Western Holdings Mines. Recently prospect drilling and a number of localised hangingwall failures indicated that the residual quartzite beam could be less than 60cm and in some instances as thin as 30cm in certain areas of the mine. The result of this is a less stable hangingwall which not only poses a safety risk to workers in these areas but also had the potential of locking up some 840 000 Tonnes of gold bearing ore. At the present gold price this amounts to revenue of approximately ZAR1.5 billion (U.S. $143 million).This paper discusses the method of “undercut stoping” and existing practices in place at Tshepong Mine. It also explores new initiatives such as the use of a simple freely-supported elastic beam solution to perform back analysis, on-site data capturing of beam thickness and support geometries in order to develop empirical design charts and numerical modelling to assist in the verification of the empirical design method."

Jan 1, 2015

By F. Hassani, E. Aflaki, M. Nokken, M. Kermani

"This paper presents and compares the physical properties of Gelfill and cemented hydraulic fill (CHF) obtained by lab experiments. Gelfill consists of tailings, different binders such as Portland cement, fly ash and blast furnace slag and an alkali activator such as sodium silicate. The CHF and Gelfill samples with various mixture designs were cast and cured for 28 days. The influence of sodium silicate concentration, pulp density and mixing time on the mechanical properties of samples were evaluated using the uniaxial strength test. Mercury intrusion porosimetery (MIP) was used to analyse the microstructure of CHF and Gelfill samples.This study concludes that: (i) The mechanical properties of CHF can be improved by the addition of appropriate amount of sodium silicate. (ii) The rate of strength acquisition in Gelfill samples is faster than CHF samples over 28 days of curing period. (iii) Mixing time strongly influences the mechanical properties of Gelfill samples but did not have any effect on CHF samples. (iv) The MIP analyses indicate that the pore size distribution and total porosity of Gelfill and CHF were different, and this did contribute to higher strength development of the Gelfill samples. INTRODUCTIONThe increased depths of mines in the Canadian Shield and the high stress associated with these depths favour a new method of mine backfill that can both meet strength requirements and help mine productivity. The mine backfill mainly consists of tailings, water and binder materials, the latter being most expensive. Gelfill is a new mine backfill material whose binder usually consists of alkali activators such as sodium silicate and other cementitious materials such as blast furnace slag and normal Portland cement. Although sodium silicate has been used in concrete manufacture, the use of this material in mine backfill is relatively new (Doucet, 2007, Razavi, 2007). Until very recently there have been only a few isolated publications, mostly out of McGill University, regarding mine Gelfill (Razavi, 2007 and Kermani et al., 2009 and 2010). These papers have investigated some of the basic mechanical properties and mechanical behaviour of Gelfill. However, the physical performance of Gelfill in various conditions has yet to be understood. Therefore, the main objective of this study was to investigate the influence of mixing time and sodium silicate concentration on the mechanical performance of Gelfill and CHF through a series of experiments. Moreover, the microstructure of the Gelfill and CHF samples was studied."

Jan 1, 2015

By Robert B. Parsons

"The 1994 Quebec Budget included a significant overhaul of the mining duties sys-tem in that province: broadening the base and lowering the rate, all in the name of “ensuring the integrity of the taxation system"" and ""enabling the State to collect fair compensation "". The reforms hit hardest on the small, lightly-capitalized producer, by repealing the basic annual exemption, limiting the refund for losses, and significantly reducing the investment and processing allowances. There is some relief provided in the form of faster depreciation rates and a lower nominal tax rate, but the thrust of the overhaul is clear -higher taxes on the mining sector.IntroductionAlthough Quebec's mining tax regime represents under 10J0 of the province's revenue base, and was significantly reformed in 1979 and 1985, the May 13, 1994, provincial budget introduced further significant changes to the Mining Duties Act, The hope (on the part of the province) is to reduce the provincial ""subsidy"" for mining by $20 mil· lion per year by 1996."

Jan 1, 1995

New Millennium Capital Corp. shall not be liable or responsible for any claim or damage, direct or indirect, special or consequential, incurred by the user arising out of the interpretation, reliance upon or other use of the information. Users should not rely on information for any purpose other than for gaining general knowledge of New Millennium Capital Corp. Although New Millennium Capital Corp. believes that its expectations reflected in these forward-looking statements are reasonable, such statements involve risks and uncertainties and no assurance can be given that actual results will be consistent with these forward-looking statements.

May 1, 2011

By P. Sauriol

This work addresses the design challenges and demonstrates the capabilities of a novel water transfer factor measurement apparatus. Several measurement concepts were screened on the basis of their water transfer factor accuracy using Monte-Carlo generated virtual experiments. The most promising measurement concept was assembled and tested to assess its actual measurement accuracy. For these concept validation experiments, the polymer electrolyte membrane fuel cell was simulated by adjusting the water injection rate to corresponding levels. Combining the anode and cathode measurements, the water transfer factor accuracy was typically better than 0.01. Real-time measurements of the water transfer factor on both anode and cathode sides of a polymer electrolyte membrane fuel cell were achieved. The anode and cathode side measurements were in good agreement with each other; however the anode side measurements were generally more reproducible. A parametric study showed that stream humidification plays an important part in the water transfer across the membrane electrode assembly. Finally the water transfer factor along the channel of a 300cm2 co-current fuel cell was obtained by using a series of six 50cm2 sub cells. The results were in good agreement with predictions from a recently proposed model.

Jan 1, 2005

By E. Topuz, C. Duan

"INTRODUCTIONOperations research (OR) applications have experienced a substantial growth within the mining industry during the last three decades. The purpose of this paper is to present a summary of the results of a comprehensive survey of the application of various OR techniques to the major mining activities. It is hoped. through this sur vey , that the most widely used OR approaches, the important areas of application, and future trends have been identified.This survey included more than 500 articles published in this field in English since the late 1950s. Most of the relevant literature was found in mining publications, but, in terms of quality and originality, important applications were also found in literature not related to the mining industry. The sources constituted periodicals, proceedings research reports, and a few books. A listing of selected publications from which three or more articles reviewed in this survey appear is given at the end. Operations Research MethodologiesOperations research is concerned with optimal decision making in, and modeling of, deterministic and probabilistic systems that originate in real-life situation s. One basic feature of the OR methodologies is the attempt to optimize certain design parameters, subject to a set of constraints. This distinction has been employed in the survey as a guideline for selection of the techniques covered under the title "" OR methodologies"". The methodologies thus encountered in the literature are listed below. In a few cases, simulation has not been considered because it is not an optimization method per se."

Jan 1, 1989

"Process specifications for classification system design f or closed circuit grinding are identified. A computer-assisted, mass balance procedure for estimation of material size distributions and required hydrocyclone separation performance is presented.GeneralClassification equipment application involves a large number of variables, but can be greatly simplified by consideration of the following two major steps:(A) Process analysis, in which the so lids and liquid material balances and solids size distributions in the three classifier streams are determined in order to establish the required classifier separation performance.(B) Equipment selection, in which the cyclone dimensions and feed conditions are selected to yield the de sired separation, and the number of units then determined by their capacity rating."

Jan 1, 1984

By R. del Villar, A. R. Laplante

"This article presents four grinding simulation programs, written in Applesoft BASIC. The firs t two calculate residence time distributions (RT Ds) for open and closed loops mills. The third program calculates the select ion functions from the RTD, breakage function and particle size distribution (PSD) o f the feed and discharge. Two linear regression programs are also included to calculate the breakage function. These results are used in the fourth program to simulate continuous or batch grinding kinetics.The modelling approach presented is the size discrete, time continuous matrix formulation presented by Reid (1965) from concepts originally proposed by Epstein (1948). It is at the present time the most widely accepted phenomenological model of grinding kinetics and is standard textbook material (Austin et 01., 1982; Kelly and Spottiswood, 1982, p. 152). The concepts of RTDs and tracer testing originated from chemical engineering theory and practice, and are well presented in Leven spiel (2n d Ed . 1972 , Ch. 9) .Applesoft* was chosen because it is compatible with many micro computers. It is also one of the simplest and least powerful BASIC versions. Thus it can easily be adapted to other more complex BASIC versions.Open Loop Residence Time Distributions (Program RTDOPEN)As mixing, channelling, stagnation and short-circuiting all affect slurry motion in tumbling mills, transport characteristics are very complex an d cannot be derived from fundamental principles. Fortunately , as grinding follows first order kinetics, transport characteristics for the purpose of grinding simulation ca n be represented by the RTD of the slurry phase . It is normally determined using liquid tracers, as it has been demonstrated and is commonly accepted that in industrial ball mill s, the RTD of the so lid phase is particle size independent and equal to that of the liquid phase."

Jan 1, 1985

By J. E. Carter, D. P. Wall

"This paper details the highlights of the open-pit and underground operations of Mclntyre Mines Limited in the Smoky River area of Alberta. Mining methods, operating equipment and manpower are outlined, followed by a discussion of reclamation and environmental control.IntroductionMcintyre Porcupine Mines Limited was incorporated in 1911 and for many decades was known primarily as a gold producer in the Porcupine district of northeastern Ontario. The company, however , has held coal leases in the Smoky River area, near Grande Cache, Alberta, since 1921. Preliminary studies were carried out in the region from 1959 to 1963. In 1964, Mitsubishi, a leading Japanese trading company, (on behalf of Mcintyre), investigated the area as a possible source of coal for the Japanese steel industry. The initial report concluded that Smoky River coal was of high quality, comparable with some of the best metallurgical coals in the world."

Jan 1, 1981

"In the past year, mining at the Doyon Mine has shifted entirely from open pit to underground. The mine produced 234 692 ounces of gold in 1989 and is expected to produce 225000 ounces in 1990. The Doyon Mill has been running slightly above design capacity, and recovery has increased 3%.IntroductionThe Doyon Mine is located 25 miles east of Rouyn-Noranda, Quebec (Figure I).It is a joint venture owned by Lac Minerals and Cambior, with each holding a 50% interest. Lac Minerals operates the mine under the direction of a management committee.Production at the Doyon Mine began in 1980 with the start up of the Main Zone pit. Shortly thereafter the Doyon Mine became the largest open pit gold producer in Canada.In 1983, a ramp leading to the fourth level and exploration drifts were driven. Results were very encouraging, therefore the decision was made to sink a 2150-foot deep shaft, which was completed in 1986.In mid-1986, production began in the West pit, while underground mining of the West Zone started shortly thereafter, at the end of the same year.In 1987 the mill capacity was increased to 3300 tons per day and the Main Zone underground operations commenced."

Jan 1, 1990

By Greg Johnson

Maintenance needs information about assets to optimize availability and production needs information about performance and consumption to maximize output. In considering both these needs together as, ?Asset Optimization?, the information systems that support them are critical. The theory of Asset Optimization derives from the Lean Manufacturing concepts developed by Toyota, but some changes are required to apply this to mining operations. In particular, mining operations require automated systems due to their geographic spread and they need a strong emphasis on capturing under-performance losses as well as delays and stoppages in production. Leading metal miners and coal miners alike have applied these systems to good effect in the last 10 years. The concepts developed initially in minerals processing plants are now being applied to the mines themsleves as well as the mining logistics chain. Production increases of 5?10% are achievable with the right implementation and consideration of the some key lessons learnt in the last 10 years. Putting these lessons into action is one key step in the goal of optimizing asset performance and thus utilizing the resource at lowest cost.

Aug 1, 2013

By D. E. Salman, R. R. Maclachlan, R. J. Barclay

"There is a considerable resource of data for spherical charge cratering, both as single charges and in row-of-charge geometr(1). The data are. however, based on cratering performance to a single free planar surface.In practice. the more common circumstance involves an angular surf ace geometry. such as occurs at the toe of a bench or the wall of a stope. It is for the purpose of investigating this circumstance that the described test work was conducted.The test objectives were: (1) to observe the change in single-charge cratering performance between planesurface and angle geometry; (2) to identify the optimum performance of single charges cratering to a plane surface. cratering from a bench sub-grade position and cratering from a condition of zero sub-grade or stope wall geometry; and (3) to observe the performance of row-of-charges cratering to an angular surface at various row burials and spacing. The row charge burial and spacing dimensions were to be expressed in simple numerical multiples of single-charge depth-of-burial data."

Jan 1, 1981

By John E. Udd

The stability of a rock mass is influenced by the presence of discontinuities. In assessing stability, it is required that one should know the frictional and cohesive properties of these contained weaknesses. In the study performed by the authors, a number of samples of diamond drill core containing open discontinuities were tested in shear. The results obtained were compared with values which resulted from back analyses of instabilities in the field.

Jan 1, 1979