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By Esteban M. Domic

"T.L. Leaching ProcessCommercial PerformanceSociedad Minera Pudahuel Ltda. (SMP) has been innovating in the copper producing field with the commercial application of the Thin Layer (T .L.) leaching process in its two operating division s: Lo Aguirre and La Cascada. Since November 1980, SMP' s Lo Aguirre Division has been producing high-purity copper cathodes at a nominal rate of about 16,500 metric tonnes / year, by mean s of the new route of T.L. leaching, followed by solvent extraction and electrowinning (TLlSX/EW). This has been the first commercial application on T .L. technology in the world, and the only commercial application in Chile for solvent extraction and electrowinning.By mid -1980, SMP acquired Sagasca Mining Co., renaming it as La Cascad a Division. The existing vat leaching facilities were modified to apply T.L. in the same old vats. The existing scrap iron cementation recovery circuit was kept running for the continuing production of copper precipitates. The modifications in the leaching circuit allowed shorter treatment cycles with a lower acid consumption and consequently, copper product ion increased from a previous historical high of 12,000-13,000 metric tonnes /year to a new level of about 22,000 metric tonnes/ year . These changes have been in operation since March 1981.T.L. Leaching commercial performance, both at Lo Aguirre (TL / SX /EW) and at La Cascada (TL/cementation), has been presented in several recent publications. Real operating parameters and process requirement s were reviewed in detail. A breakdown for TL / SX/ EW economics was also published based on Lo Aguirre' s performance during 1982(41."

Jan 1, 1986

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 J. W. Hendry

"This paper will discuss the application of tools and the evolution of computer-assisted procedures in the production planning process at Quintett e Coal Limited (QCL). In 1986, QCL produced 5.3 Mt of clean coal from their surface mining operation located in north eastern British Columbia. The structural complexity of the sedimentary deposit and high rate of mining necessitate the consideration of large amounts of geological information which continually updates the interpretation. There are multiple unit operations required during the process of mining through a given multi-seam sequence, which results in many interdependent faces, and multiple iterations of scheduling sequences in order to satisfy a given set of objectives. In order to facilitate these activities in a timely fashion, it was recognized that a computer systems' capability needed to be developed which could increase the efficiency of information input, manipulation and output. IntroductionQuintette Coal Limited (QCL) has been operating a large metallurgical open pit coal mine in northeastern British Columbia, since 1982. The mine produced 5.3 Mt of clean coal in 1986 for export to Japan. Throughout the start-up period and the subsequent build -up of production levels, it became evident that the primary producing area was comprised of extremely complex faulted structures. This has resulted in development and modification of specialized mining methods employed to effectively recover the resource. Similarly, the planning and engineering techniques employed have been evolved over the same period of time. The implementation of computerized methods has been one of the major developments in this process, including geology interpretation, modelling, reserve definition, quantification, production planning and scheduling, and graphical plan presentation. These capabilities have been employed, in various forms, for project scale feasibility work and long range planning for some time, however, the use of computer tools for short-term, detailed production planning of a complex mining environment presents a different set of problems. It is hoped that a presentation of the current state of evolution and future plan s for development will be of interest to organizations considering implementation of a similar system."

Jan 1, 1988

By C. Beaudry

Outline ? General Geology of Frieda River Project Area ? Exploration History ? Geology of Porphyry Deposits ? Porphyry Resource ? Update of Nena Deposit and High-Sulfidation Mineralization ? Nena Resource

May 1, 2006

By M. Korchynsky

"The key words which characterize vanadium are: unlimited availability, versatility of applications and price stability. The supply of vanadium is assured by diversified sources, distributed all over the globe. The inexhaustible raw materials base is complemented by a strong vanadium industry. Both the fully integrated vanadium producers and converters of vanadium oxide or vanadium-containing slags or residues guarantee an adequate supply, commensurate with the steady growing demand.The major share of the world's vanadium output is being consumed by the steel industry. As an additive to steel, the versatility of vanadium is particularly impressive. A few hundreds of one per cent of vanadium convert plain carbon steel into high-strength, low-alloy steel with more than double strength. On the other extreme, high-speed steels made via the powder metallurgy route show superior performance with vanadium additions as high as 6 or 8 percent. Vanadium is used as a cost-effective alloying addition in steels for high-temperature service, fully alloyed heat-treatable steels, new dual-phase steels for automotive components, rail steels, etc., to mention only a few applications. Vanadium is also an established essential addition for titanium alloys. The chemical industry is relying on vanadium compounds as important catalysts.In spite of a wide diversity of applications and continual growth in consumption, vanadium has exhibited, over the past several decades, a remarkable price stability, free of conjunctural fluctuations. Because of its availability and versatility, it will continue to be one of the key metallic elements for future technologies.Key Features of VanadiumIn attempting to single out the key features of the metallic element vanadium, three descriptive characteristics come to mind: availability, versatility and price stability."

Jan 1, 1982

By Eric Pirard

"A mineralogical and trace element analysis was performed on the Küre historical slags in order to evaluate the possible recovery of copper and cobalt. Reflected light microscopy, electron microprobe and image analysis were combined to determine the Cu and Co distribution in the slag.The results indicate that 81% of the total cobalt is chemically combined in the fayalite whereas only 3.4% is in the mechanically entrapped sulphides. The remainder being in hercynite and wiistite. On the other hand, 95% of the total copper is in the sulphide phase.This kind of applied mineralogical investigation gives invaluable information when it is performed preliminary to metallurgical experiments.IntroductionThe recycling of metallurgical slags is a growing business. The operation is directed toward recovering base metals (Cu, Pb, Zn), and by-products (Floyd and Mackey, 1981).Two reasons are invoked to explain metallic losses in slags: (1) mechanical entrapment of matte globules in the silicate melt; and (2) chemically combined metals in the slag-forming phases. Obviously, a chemical analysis of the slag cannot distinguish between those two modes. Grinding and flotation of the liberated sulphides have often been used to evaluate the importance of mechanical entrapment (Mechev, 1970; Imris , 1982).Recent studies in applied mineralogy of pyrometallurgical products (Bérubé et al., 1987; Pignolet et al., 1986) have demonstrated the benefits of quantitative mineralogical analyses of slags. Optical microscopy together with electron microprobe and image analysis offers a powerful and easy way of quantifying the relative importance of mechanical and chemical losses."

Jan 1, 1991

By J. A. Finch, G. Labonté

"A long-standing objective has been to obtain interpretable measurements of the oxidation-reduction potential in mineral slurries. For this purpose several sensing electrodes (black platinum wire, platinum foil and spiral, gold foil and spiral, and sulphide minerals such as chalcopyrite and galena) were investigated to determine their response to the presence of sulphide minerals in the pulp, and to the addition of reagents commonly used in flotation. The observed discrepancies between the electrodes may be explained using a combination of the classical mixed potential model for complex solutions and the probability of contact between the mineral particles and the sensing electrode. It is shown from laboratory testwork that gold spirals are preferred over platinum electrodes. Finally, some of the practical aspects of using the electrochemical measurements in a plant environment are discussed.IntroductonThe interpretation of flotation of sulphide minerals in terms of electrochemical (electron transfer) processes has brought new possibilities for process control of selective flotation. Investigations on massive and compacted particulate bed electrodes have shown that the flotation of a given mineral in the presence of a collector can be controlled by the potential induced on the mineral surface. Also, phenomena such as collector less (self-induced) flotation, activation by heavy metal ions, and natural selectivity sustained by galvanic coupling during flotation might also be controlled by electrochemical means.The technique for measuring electrochemical potential in slurries is an adaptation of that used for solutions. The measurement of the oxidation-reduction potential of a solution (ORP , Redox, Eh) is usually carried out by immersing a noble metal electrode (platinum, gold or silver) and a non-polarizable reference electrode: Standard Hydrogen Electrode (SHE), Standard Calomel Electrode (SCE), or silver/silver chloride (Ag/AgCl) in the solution. (The abbreviation Eh implies the SHE is the reference electrode.) The potential difference between the two electrodes is measured using a high impedance electrometer. ASTM standard D 1498-76 (revised 1981)(1) covers the practical details of such measurements; however, it does not deal with their meaning either in complex solutions or in mineral slurries ."

Jan 1, 1988

By Michael Farley, Paul Dufour

"Relationships, Partnerships,Marriages (RPM)RPM has a nice musical ring to it, but it is in fact synonymous with science and technology, university-government -corporate links and the more genera l issue of university roles in technology development. Pick up any report on one of these issues, and chances are that you will find one of these key words in the title. Play it, and you will find that the revolutions per minute are increasing. It is difficult to keep track of the wide variety of institutional experiments now developing in Canadian universities in attempts to marry science and research with technology commercialization and technology transfer.Why is the role of Canadian universities in this matter important? There are at least five good reasons:1. It is important because these knowledge institutions are producer s of scientific research, a major component of technology. Today the gap between the two is rapidly shrinking.2. It ' is important because Canadian industry is turning to universities for tech no logy development and new knowledge. Figure 1 shows that universities are becoming an important source of technology available to Canadian firm s; more important in fact than government. Figure 2 illustrates this trend more graphically in showing that university collaboration is one of the preferred methods of industry participating in co-operative R&D efforts:3. The role of Canadian universities in technology development is also important because the provincial and federal governments have embarked on various programs and policies for promoting the use of technology and science for economic benefit. Universities are playing an increasing role here. For example, the submission of IDEA Corporation (a venture capital operation funded by the government) in Ontario to the Bovey Commission on the Future Development of Ontario Universities clearly spelled out its ideas for commercialization of university research in Ontario . Among other things, the brief suggested that Ontario's universities need to be better equipped to transfer technology, and the reward structure in university research must incorporate industrial interests."

Jan 1, 1986

By Michel David

"The usual complaint of mines is that grade does not match exploration expectations. Quite often, more tons are mined than expected but at a lower grade. This can be seen as dilution. Geostatistics can help predict which dilution can be expected both in terms of grade and tonnage for different mining methods.The usual vocabulary of geostatistics speaks of block distribution; block variance, size effect, information effect, all terms which say very little to the practitioner. In f act, all this can be rephrased in terms of dilution .In this paper, the following is presented - an example which shows how reserves change with the size of selection units and number of samples taken, and tables which show the dilution that are bound to happen when dealing with the commonly encountered log-normal distribution. Finally, the paper shows how grade tonnage computations should be made in the case of an arbitrary distribution. IntroductionGeostatistics progresses more and more rapidly if one judge s by the number and quality of papers published in Mathematical Geology or at APCOM meetings. More and more case studies describing successful applications are published (David et al., 1986)(Kwa and Mousset-Jones, 1987). It is estimated that more than 270/0 of the gold mines around the world use geostatistics. There is still, however, a lot of resistance from the remaining 73%. Geostatistics has more formulae and equations than it needs to reach year 2000. We will be well into the third millenium before all the models available now are actually used. The progress may come in the form of finding better ways to present known statistical results and getting away from the jargon of geostatisticians. One example may be in trying to explain how we can answer the most common plea of the mining industry: production grade is not what was expected in the feasibility study."

Jan 1, 1988

By V. Schenk

Dust exposure resulting from the exploitation and winning of natural resources below ground has presented a serious health problem since the beginning of mining. The boom phase of the German hard coal mining industry after World War II with at times up to 500,000 employees saw an increase of dust exposure of miners below ground as the mechanization of road heading and mining increased significantly. More and more miners were diagnosed with coal-workers-pneumoconiosis (CWP), a chronic and irreversible lung disease resulting in a significant impairment of pulmonary function. This realization led to a reduction of CWP in the German hard coal mining industry in the 1960s. The successful fight against CWP began with the introduction of technical dust prevention measures. By infusing the coal seam with water before mining, sprinkling and spraying of heading and mining machines as well as canopies with water, aspiration in places with high amounts of dust and the suppression of dust with chemical substances it is possible to significantly reduce the miners? dust exposure. All operating points below ground are checked and measured regularly with regard to dust exposure. Through the combination of these values together with the individual shift data a relatively precise profile of individual dust exposure can be obtained. This profile allows the targeted work assignment when certain predetermined limits have been reached, moving the miner to a work place with less dust exposure and thus reducing the chronic dust exposure. The state of health of the individual is known because since about 60 years ago extensive occupational health checks have been carried out regularly at least every two years which means that work restrictions can be imposed depending on the findings. Since the beginning of the 1980s more value has been attached to not only situational but also behavioral prevention. Given the comprehensive provision of protective masks, having a protective effect as well as the required comfort when being worn, each miner has the opportunity to protect his respiratory organs depending on the specific dust exposure. Through a combination of all these measures the German hard coal mining industry has succeeded in beating the classic coal miner?s disease CWP. For mines in the Ruhr valley this means that a miner who started work after 1978 will no longer develop CWP.

Aug 1, 2013

By R. Mariano

"The ability to optimise a concentrator from mill feed to final products requires a process simulator that integrates comminution, classification and separation stages. A key part of any such integrated process simulator is the inclusion of a model of mineral liberation in comminution to predict the particle composition distribution of the comminution products. This need was recognised by Gaudin (1939) who proposed a model of liberation based on the cubic fracture of a mineral texture composed of cubic grains of two minerals.This paper describes the development of a texture-based model of mineral liberation that builds on the method proposed by Gaudin. The approach described here, termed the JK-Gaudin Random Liberation model (JK-GRLM) uses as its basis the measured, volumetric mineral texture data that can be quantified for a given ore using X-ray micro-tomography. The textural data required as inputs for the JK-GRLM include the mineral grain size distribution. While the Gaudin model (in common with other existing liberation models) is a two-mineral (or two-phase) system, the JK-GRLM extends the approach to multimineral systems of up to 15 individual minerals, making it more widely applicable.An example of the application of the JK-GRLM to a base metal sulphide ore is provided. In the example the JK-GRLM is used to simulate the breakage of the measured ore texture and the particle composition distributions of the simulated progeny particles are compared to the measured particle composition distributions of ore that has been physically broken.The ability to calibrate this mineral liberation model with measured ore texture will allow it to be applied in greenfield situations where geometallurgical programs measure texture and in brownfield applications as a key part of integrated process simulations. The development of this model enhances our ability to simulate mineral processing operations as an integrated system."

Jan 1, 2016

By D. L. Churcher, R. J. Perry

"In recent years much work has been don e to examine alternate underground backfill support systems with the objectives of improving ground support and reducing mining costs. This report deals with the work conducted at Placer Dome Inc.’s Dome Mine to develop a high density backfill system, taking advantage of the unique properties of this fill material, to address a backlog of large open stopes to sustain stable minewide ground conditions for future generations of Dome miners.IntroductionDome Mine began its existence in 1909 with the discovery of visible gold on a dome shaped outcrop located west of Porcupine Lake in northern Ontario. The orebody beneath this outcrop has supported one of Canada’s premier gold mining operations for 80 years. Production during this time of over 46 000 000 tons of ore has resulted in the recovery of II 500 000 ounces of gold and 2 000 000 ounces of silver. Mining continues today at a production rate of 3500 tons per day, with ore coming from both underground and open pit operations.During the life of the mine, different underground mining methods have been used to extract the ore from a complex deposit consisting of single and multiple vein structures.Cut-and-fill mining was introduced in the 1930s using sand fill and later hydraulic fill for support and to provide a working platform. A total of 1 800 000 tons of sand fill and 7 300 000 tons of hydraulic fill have been placed underground in cut-and-fill stopes. Until the late 1960sshrinkage mining was used extensively, particularly in narrow, steeply dipping zones. Bulk mining with small diameter longholes was introduced about this time, to take advantage of low production costs. Longhole blasting has often been used to recover low grade ore from the walls or sills of old shrink stopes, resulting in large open stopes. Backfilling of these open holes has been restricted to smaller stopes and associated with local ground conditions.In the late 1970s it was recognized that the number of large open holes which were being generated presented serious regional and minewide stability problems for future operations. With higher gold prices, economic ore reserves were being tied up in areas adjacent to multi-level open stope complexes. To stabilize these stopes and allow access, backfilling would be required."

Jan 1, 1990

By Marc Lavigne

"The Lac Knife graphite deposit was estimated, as part of a feasibility study, using a geostatistical ore reserve estimation method: ordinary kriging. Based on the geology and its interpretation, the results of a variogram study, and the statistical parameters of the grade distribution of the core samples and the composites through the mineralization, the deposit was divided into three separate zones (west, centre and east), and each of these zones was then analyzed and kriged independently.The geological ore reserve estimation results of ordinary kriging are compared to the results of a conventional method (sections) used previously. The two methods gave almost similar reserve figures. The conventional method provided a +2% estimation for tonnage and + 10% for grade because it ignored the spatial relation between sections and samples, and ordinary kriging gave a more accurate longitudinal definition of the deposit.Finally, the paper concludes with the advantages of proceeding with ordinary kriging, namely: higher flexibility (change of cut-off grade), better deposit resolution and enhanced selectivity for the design of the open pit.IntroductionWithin the context of a complete feasibility study for the Société d' Exploration Minière Mazarin Inc., specialists of the Mines and Geology Division of Roche Ltd., Consulting Group, defined a modelling method appropriate to the graphite deposit of the Lac Knife property near Fennont. Many patterns were considered. Based on the geology of this deposit, the planned mining method, the statistical parameters of grade distribution and the variogram study, the process of reserve estimation retained was to use the ordinary kriging in a selective way. It was required because the geometry of the deposit is such that it was unthinkable to apply ordinary kriging without restrictions.This paper gives a detailed explanation of the observations and interrogations which led to the choice of this ore reserve estimation method, and the calculation procedure itself."

Jan 1, 1991

By H. Utsunomiya, Mehdi Sanjari, Abu Kabir, Steve Yue, Jing Su, L. Kestens, In-ho Jung

The microstructure and texture evolution of low temperature rolled AZ31 magnesium alloy during annealing were investigated. The specimens were rolled at the temperature of 100? at a high rolling speed of 1000m/min with a reduction of 30% in one pass. Annealing was conducted at various temperatures ranging from 200? to 500? for different time. To study the effect of fast speed rolling, the same annealing procedures have been applied for the specimens rolled at a significantly lower speed of 15m/min. The microstructure was characterized by optical microscopy and scanning electron microscopy, while the texture was analyzed by X-ray diffraction analysis and electron backscattered diffraction analysis. Texture weakening occurred during annealing at both fast and slow rolling speeds. However, at the same annealing condition, fast rolled specimens always had weaker intensity of basal texture than slow rolled ones.

Jan 1, 2014

By A. David MacPhail

"Highland Valley Copper is a large volume producer of copper and molybdenum concentrates. Production is by conventional truck and shovel operation combined with an extensive ore handling in-pit crushing and conveying system.Grade of the two orebodies is low at 0.4% copper and 0.007% molybdenum and this demands a production rate in excess of 260 000 tpd at a stripping ratio of 1: 1. Mining cost has to be kept at minimum levels to keep the mine profitable and thus, it is necessary to keep in the forefront: of technology. As well as the in-pit crushing system, the mine has pioneered the use of shovel weighing coupled with a state-of-the-art dispatch system.Maintenance of the equipment is carried out at the on-site mine maintenance shop with assistance from local shops for engine and wheel motor rebuilds and other large jobs such as those requiring stress relieving. Shovel and truck rebuilds are undertaken by mine crews. Both long- and short-term planning is designed and scheduled in the mine engineering section. Outside consultants are used to assist in slope design, reclamation and blasting technology."

Jan 1, 1992

By L. D. Smith

"Those who submit competing proposals for projects seek to present senior management with complete and fully supported material that will not fail under questioning. Hopefully, misleading notions and omissions will have been minimized and there will have been testing of the assumptions regarding the economic, social and political environments.A capital project evaluation team can do management and itself a service by including a sound approach to the impact of inflation (and its twin problem, interest) on a project and a great disservice with an inappropriate approach to inflation.InflationHandled deftly, inflation can alter a project evaluation to show almost any result the handler desires. It must be a constant source of frustration for design people and cost estimators to spend weeks perfecting the technical aspects of a project in order to minimize costs, only to have all of their efforts set awash in a sea of financial and economic assumptions that submerge all of the detail. In all of this, inflation is perhaps the largest offender, with inflation criteria often being brought to bear at the last minute, almost as an afterthought. Perhaps this tardiness reflects the difficulty of the subject and the belief that senior management will take its own approach to the problems of inflation. Such a belief is unfair to senior management, for it is entitled to not being misled by omission. It is entitled to the full use of the skills of the evaluating team, including reasonable assumptions of the impact of inflation.Working in a consulting context, one has the opportunity to participate in the evaluation of a large number of projects."

Jan 1, 1990

By Keith C. Hendrick

"Metal prices are frequently the most critical and least predictable element in determining the profitability of mining operations. Short -term fluctuations can be offset in varying degrees by hedging or other market actions. Such solutions are not practical for the longer term, The paper investigates the nature and extent of metal price risks and evaluates methods to reduce them.IntroductionIt is management's responsibility to improve the odds by managing the-risks by identifying them clearly, assessing them accurately, minimizing them where possible-and, then, timing decision s success fully.In determining the profitability of current operations, preparing forward plan s or developing feasibility studies for new projects or expansions, pr ices are usually the most critical input. Being market determined rather than cost based, they can also be the most unpredictable As a result, commodity prices are frequently the greatest of all risk factors.Nature of Commodity PricesThe cyclical nature of commodity prices is well known. They are stable only when supply is in balance with demand and forecast to remain that way. An imbalance on either side of the equation can lead to a price reaction completely out of proportion to the actual or perceived surplus or shortage.This exaggeration arises through the cumulative effect of market forces. When the market senses an uptrend, consumers buy for the expected increase in activity. They also seek additional quantities for inventory before price s rise. Merchants defer spot sales anticipating higher price s, speculators go along for the same reason, and producers raise prices in response to demand. Events tend to confirm the expectation of each party and strengthen their reaction causing prices to move higher."

Jan 1, 1983

By L. Nutter, J. Clancy

"Barite is used extensively by the oil and gas well-drilling industry as a weighting agent. It is particularly well suited for drilling mud because of its qualities; it is non-abrasive, heavy, virtually inert chemically, easy to handle and inexpensive compared to other available heavy materials. Increased deep well drilling in Western Canada, and especially in the Arctic regions, could dramatically affect the demand for barite through this decade. Known deposits in northeast British Columbia are possible sources of incremental barite supplies, should the situation develop.IntroductionThe purpose of this report is to examine the opportunities for expanding barite production in British Columbia. Of primary interest will be the relationship between the projected future levels of production and consumption of barite in Western Canada and the extent to which increased domestic production could replace the need for imports in filling any expected supply shortages.After a brief overview of the nature and uses of barite and some of the relevant features of the barite supply industry, the discussion will turn to the supply gap in the Canadian market and the possibilities for import substitution.OverviewBarite is an industrial mineral which is used in large quantities by the oil and gas well-drilling industry. It is often an important component of drilling mud, a fluid circulated continuously in the well during the drilling process to lubricate and cool the drilling apparatus and to contain the high oil and gas pressures found at depth. Barite (BaSO4) is particularly well suited as a weighting agent for drilling mud because it is a heavy (specific gravity to 4.5) inert mineral which is inexpensive in relation to other materials having a high specific gravity. In the on-site use of drilling mud, ground barite is combined with numerous other solid ingredients and chemicals in the form of a slurry. Other advantages of barite include cleanliness, ease in handling and its non-abrasive character (hardness of 3-3.5)."

Jan 1, 1982

By Godfrey W. McDonald, Dennis E. Fredrickson

"Commercial coal mining has been recorded in Nova Scotia since 1863 and during this period an estimated 60,000,000 short tons of mine discard containing 10 1030% coal has been accumulated, Approximately 70% of these dumps are in the Cape Breton region and most are owned by the Cape Breton Development Corporation (CBDC), formerly DEVCO.The explosion of oil produced energy costs which created an increase in thermal coal demand as well as the desire to rehabilitate abandoned mine dumps encouraged coal reclamation. CBDC was receptive to a proposal from the Selminco Joint Venture and encouraged the building of the Princess Recovery Plant (1980) and The Summit Plant (1982).The mine dump contains scrap, waste rocks, coal and substantial quantities of fine shale. The scrap and oversize are removed and the remaining material slurried with water to a density of 1.45. The slurry is cycloned to separate the saleable thermal coal from the rejects which are returned to designated areas of the dump for contouring and revegetation.BackgroundThe recorded coal production in Nova Scotia from 1863 to 1980 was 390,000,000 short tons. This extraction was associated with an estimated 60,000,000 short tons of discarded material. This mining discard and coal washing plant reject are located in numerous, varying sized dumps throughout the mining areas. Approximately 70% of these dumps are in the Sydney coal field region of Nova Scotia. The coal content of these dumps varies from 10 to 30% coal with an average of 18%.Energy CostsThe explosion o f energy costs in the mid-1970s greatly increased the sale price of thermal coal which made recovery of coal from some of the dumps economical. The environmental benefit of these operations will be the rehabilitation of the dumps upon cessation of the coal reclamation operation."

Jan 1, 1983

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