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By Gui Hua Wang, Xin Chang, Zhong Ying Han, Yuan Fang Cheng

"According to the geometrical characteristics of triangular meshes, Triangular Mesh Split Model (TMSM) based on a finite element method is proposed to simulate cracks propagation of fractured rock. With TMSM, stress intensity factors at the tip of cracks are obtained by far-field contour integral. Meanwhile, vector cross multiplication is adopted to fix the cracking unit, and maximum circumferential stress criterion is used to determine the crack propagation angle. Then crack dynamic propagation simulation is realized through local mesh split or node movement at crack tip. With this method, the crack can split apart a unit or extend along the mesh boundary, so the crack could extend along an arbitrary path and is not restricted by the initial mesh. The applicability of the mesh split algorithm is verified by the crack propagation examples of wing crack and multi-fractured rock mass with holes. The results show that this method not only has higher accuracy of fracture parameters calculation, but also can accurately simulate the crack initiation and propagation of rock under complex stress state such as tension, compression and shear. In addition, the far contour integral is introduced to determine the crack tip stress intensity factor and there is no need to reconstruct a singular element at the crack tip or to intensify the meshes. Compared with the existing mesh reconstruction algorithm, this method significantly improves the computational efficiency.INTRODUCTIONGenerally, rock is neither the full continuum, nor entirely discrete body, but rich in geological defects, such as joints and cracks. A large amount of geotechnical engineering practice shows that most fracture of rock is closely related to the internal joints, cracks and crack expansion (Horii et al., 1985; Wong et al., 1998). Although the classical theory of fracture mechanics established the theoretical foundation of crack initiation, propagation, so far it is still extremely difficult to characterize the propagation of airfoil-typed crack and the interference problem of multiple cracks. Up to now, the micromechanics mechanism research of crack propagation of fractured rocks has still been a hot research topic of rock fracture mechanics."

Jan 1, 2015

By D. DeGagne, E. De Souza, J. F. Archibald

This paper describes the potential use of anew agent material for backfill consolidation, ground waste glass, to be used as partial replacement of Portland cement fractions within backfill. Significant fractions of commercial and residential silica glass production is currently utilized as waste landfill and must be disposed of at high cost and with no foreseeable environ-mental benefit. This paper also demonstrates that waste glass materials could be effectively recycled as backfill additives, and that a significant, large and stable source of additive supply, currently land filled, can be developed. This new application will generate added value for such materials, serve to promote positive environ-mental stewardship and satisfy engineering sup-port requirements in mines.

Jan 1, 1997

By Edgar Stanfield

Since April, 1923, the Scientific & Industrial Research Council of Alberta has had an analyst, Mr. W. P. Campbell, steadily employed analyzing coal samples taken by the provincial Mine Inspectors. Mr. Campbell has also analyzed a number of coal samples taken by one of the Council's Geological Survey parties. We have thus, at the time of writing, over four hundred analyses of Alberta coal, made by the same analyst, and strictly comparable. These samples come from widely distributed points, some 88 townships being represented. The stream of samples is still flowing in, and it is hoped by the end of this year that the number of townships represented will be increased at least fifty percent. The time has arrived to publish some of the data collected; but it must be clearly understood that this is merely a progress report, subject to revision as further information is obtained. Three hundred and fifty-three coal mines in the province were operated during 1923. The production per mine varied from 5 up to 500,000 tons. With this number of mines to examine (and fresh mines are being opened every year) it is a large task to make even a proximate analysis of representative samples from every mine. Any chemist will appreciate the fact that to make ultimate analyses representative of even the larger mines will be a long and tedious task. It has seemed better to make a comprehensive survey by proximate analysis and determination of calorific value before beginning the more thorough survey by ultimate analysis. This paper, therefore, deals only with proximate analyses and calorific values; and, owing to limitations of time and space, does not deal with other chemical and physical characteristics of coal, such as storage quality and fusibility of ash, important though these are.

Jan 1, 1925

By M. B. McClenaghan, O. P. Lavin, Ian Nichol

"Abstract-Exploration in most areas of Canada has to contend with problems posed by glacial overburden. In many areas exploration for gold has been based on the sampling of tills, frequently by deep overburden drilling, and analyses of heavy mineral concentrates. Notwithstanding the significant role that till geochemistry has played in the discovery of some important gold deposits over the last few years, increased appreciation of the nature of the glacial history and stratigraphy and the character of gold within till has led to the recognition of a number of ways whereby the effectiveness of exploration can be improved upon.In order for till geochemistry to be useful in exploration, a number of conditions must be fulfilled, including:1. mineralization, or alteration halo related to mineralization, subcropping at the bedrock /over­ burden interface; 2.glacial erosion and dispersal of a recognizable signature of mineralization into the glacialsediments; 3, preservation of glacial sediments containing this geochemical component (trace metal or mineral) at positions subsequently selected for sampling (normally drill sites); 4. correct identification of specific till units and associated ice movement history; 5. collection of adequately large and representative samples; 6. appropriate sample preparation and processing; 7, appropriate geochemical analyses; and 8. correct data processing and interpretation.While we have no control over the first two geological conditions, and only limited controlover till availability, we can control the quality and thoroughness of sampling, sample identification, sample preparation, analysis and interpretation. In particular attention needs to be focussed on obtaining a large enough sample to be adequately representative, an unbiased sample must be collected, together with appropriate sample processing, analysis, data processing and interpretation. It is considered that by modifying or extending existing approaches to gold exploration the chances of exploration success can be increased. In particular, analyses of both the heavy mineral and minus 63 ?m fractions of till is recommended because gold in till may occur in different size fractions."

Jan 1, 1992

By M. E. Holter

"Five main lignite seams occur in the Tertiary Ravenscrag Formation in the Eastevan area, at depths of 100 feet or less. They are named, in ascending order: the Boundary, Estevan, Souris, Roche Percee and Short Creek seams. A total sequence of approximately 250 feet is represented by the coal beds and interstratified clays, silts and sands. Strata dip to the southeast at 25 feet per mile or less and trike northeast. Large areas underlain by coal seams at shallow depths are delineated. Reserve calculations are dependent on detailed information on seam thicknesses and feasible stripmining depths. The stratigraphically higher seams are thinner on the average than lower seams and this, together with the increase in elastic size fractions in higher strata, suggests a retreat of a Tertiary marine margin to the south during the closing depositional history of coal seams and associated strata."

Jan 1, 1972

By A. D. Thomas, V. N. Rampton, S. Paradis, C. F. Gleeson

"A shallow till sampling program was completed on a 1 km grid over the St . George Batholith in southern New Brunswick. The ""B"" soil horizon was analyzed for Cu, Pb, Zn, Ag, Co, Mo, U and Sb and the heavy minerals from the ""C"" soil horizon were analyzed for W, Sn and A u. The results delineated four of five recorded W occurrences, three of four recorded Mo occurrences, all recorded Cu occurrences and one recorded Au occurrence. The results indicate that shallow till sampling in conjunction with bedrock and Quaternary mapping can inexpensively define exploration targets in terrain similar to that underlain by the St. George Batholith.A similar program was carried out in eastern Ontario involving the analysis of four separates from the till, the ""8"" soil horizon, the -50 mesh fraction, the -250 mesh and the heavy mineral fraction of the ""C"" soil horizon and humus. Also sampling was carried out near known gold occurrences at closer spacings. Regionally, anomalous results from all sample media clearly defined a large auriferous shear zone and associated splays. Over one known showing all media clearly defined the showing and a secondary zone. On the regional scale the heavy mineral fraction gave the best anomaly definition and contrast, but the -250 mesh fraction was found to be the most cost effective for defining exploration targets. For detailed surveys, humus was found to be cost-effective."

Jan 1, 1986

By J. P. Jarrell

Environmental considerations are of increasing importance in determining the acceptability, schedule and cost of expansion ofCanada's uranium processing industry. Environmental considerations must be addressed in the early stages of facility planning. This results in a dilemma, as the process data needed to predict physical environmental impacts are not yet available from process design activities. Hence, a business risk is incurred if plant design is carried forward to meet these requirements prior to project (or site) approval. On the other hand, project scheduling normally mitigates against leaving process design engineering until such time as project approval is obtained. This paper examines the experience gained in Eldorado Nuclear's proposed expansion of refining capacity as viewed by an environmental engineering consultant. The history of the project and the relationship to process design functions in the two-year period prior to the Port Granby environmental hearings are reviewed. During the Port Granby public hearing, there was a consensus that normal operation of the proposed refinery could be successfully integrated with the site's natural environmental constraints. Moreover, the radiological impact from plant operations was demonstrated to be inconsequential. However, concerns were raised relating to plant upset and accident situations. These concerns are summarized. Process data requirements identified during the environmental hearings are discussed. Finally, the concerns for on-site burial of radioactive waste are reviewed. These concerns focussed on long-term stability of the waste in the presence ofgroundwater transport, erosion and glaciers. The AECB's position on waste management with regard to this project is reviewed in light ofthe implications for design.

Jan 1, 1979

By Howard Keele

"The Whitewood Mine near Edmonton, Alberta, is owned by TransAlta Utilities Corporation and operated by Manalta Coal Ltd. Approximately 2 million tonnes of sub-bituminous coal is supplied annually to the Wabamun Generating Plant. A high water table, high groundwater pressure, and structural folds contribute to stability problems in the fine-grained overburden. Significant increases in coal recovery have been achieved in recent years through improvements in water management and mining methods. Agricultural capability of the post-mining landscape has also been improved following the completion of mining/ reclamation activities. Introduction The Whitewood Mine, located to the north of Lake Wabamun and seventy kilometres west of Edmonton, Alberta, is owned by TransAlta Utilities Corporation and operated by Manalta Coal Ltd. Figure 1 shows the location of the Whitewood Mine with respect to the city of Edmonton. The mine presently supplies two million tonnes annually of sub-bituminous ""C"" coal to the 582-megawatt Wabamun Generating Plant located adjacent to the mine. The area is characterized by a high water table-, rolling coal seams and an overburden that consists of muskeg, clay and various sedimentary layers of sand, gravel and fine-grained sandstone. These distinctive characteristics require careful attention in order to not only meet the coal delivery requirements of the Wabamun Generating Plant but also to do so economically. Historical Background A small-scale underground coal mine was opened in the Wabamun area in 1910 by the Conner Coal Mining Co. Ltd. Underground operations were continued by several operators until 1948 when the Alberta Coal Co. Ltd. opened a strip mine which was subsequently taken over by the Alberta Southern Coal Co. Ltd. in 1951. The small-scale strip opera"

Jan 1, 1985

By William Pitman

Ground instability and subsequent rock falls are a major concern in underground mines. As a result, several mining companies are conducting risk assessments of the ground support installed in their mines. Risk assessment is now commonly used to provide mine operators with a systematic process to assess the strategic risks that could lead to injury to personnel or loss of production, and evaluate possible risk control measures. Risk assessments can be carried out to identify major hazards, assess the likelihood of occurrence and consequences of each hazard and estimate the level of risk. This process allows assessment of possible remediation actions to minimize the risk and likelihood of occurrence or mitigation of the consequences to a level that is reasonable and practical. This paper presents two practical mine applications of qualitative risk assessment of ground support to highlight the benefits of this process. Yearly or bi-yearly risk assessment of mine excavations can assist mine operators in prioritizing resources and areas that require support remediation. In addition, it provides a mechanism for proactive response to reduce potential risks associated with personnel safety, equipment safety and environmental impact. It also provides a baseline against which changes in ground condition can be compared and quantified.

May 1, 2004

By J. R. Donald, K. Scholey

"Nickel has been mined and processed from the Sudbury basin for over 100 years. During this period, the process has evolved into what is one of the largest and most complex mining and metallurgical facilities in the world. This paper will describe the geology and mining of the Sudbury basin as well as the Copper Cliff metallurgical flowsheet circa 2005, including:•,Clarabelle Mill,•,The flash smelting furnaces,•,The bulk converters,•,Matte casting, separation, and processing•,The carbonyl refineries•,Carbonyl residue processing•,Copper processing•,Sulphur productsThe challenges of today and the opportunities for the future are discussed."

Jan 1, 2005

By A. Rajan

"Drawing upon the experiences of a gold extraction plant startup in the Southern Pacific, this paper will describe the importance of the commissioning phases to the project outcomes to achieve early target production despite an overall time compression to attain full plant production. Some of the highlights of the paper include: impact of roles played by the Owner’s construction and operations representatives during project commissioning, the formation of a capable and competent “Mod Squad,” availability of trained operating personnel, control over work priorities and the scope of work needed to bring the plant to safe initial operations. The commissioning team comprised subject matter experts skilled in process technology supported by “generalists” thoroughly conversant in overall plant operations. The merits of a structured team approach to brainstorm and resolve commissioning challenges as opposed to direction from individual subject matter experts is discussed. IntroductionStartup or commissioning is a unique period in the life of a project. Each stage of a project-exploration, feasibility, design, construction, commissioning, initial operations and continuing operations-requires special talents, know-how, and practices. Each stage makes particular demands of the people involved. Initial operations are no exception.Having experienced the 1997 startup phases of oxide and sulfide facilities for a gold extraction plant at a remote island in the Southern Pacific, I can attest to the many challenges and rewards. Commissioning for both facilities was extremely successful and brought the entire project on line well ahead of the targeted completion dates. Using this specific project as an example, this paper will highlight some of the key features of project commissioning. In this paper, the term “pre-commissioning” denotes all activities that lead to mechanical completion; “commissioning” occurs when feed is introduced; and “initial operations” are defined as the duration when operations accepts the system/facility and takes over."

Jan 1, 2000

By Éric Létoumeau, Julie Fournier, Sylvain Caron, Yves Breau, Martin Plante, Dominique Girard, Luc Tardif, François Robichaud

"Since 1999, COREM (formerly the Centre de Recherche Minérale) has conducted and coordinated research and development activities for a consortium of mining companies that uses the benefits and advantages of collaborative pre-competitive research. In particular, COREM’s “In Situ Optimization Group” is involved in the development and implementation of modem information technologies related to process optimization and control.The POP Project was launched in order to increase and consolidate the use of such technologies applied to mineralurgical and metallurgical processes. To ensure a successful transfer to the industry, there are a number of essential activities that have to be undertaken. These activities have been identified by COREM’s members and are grouped into three main modules:- R&D Module: research and development in universities and research centres;-Technology Transfer Module: integration of new tools into the POP Software, industrial applications and technical support;- Training Module: education of new engineers in universities and continuing education of plant personnel through on-site workshops.This paper outlines the opportunities that led to the definition of the POP Project, presents its main objectives and describes its main modules. The main features of the POP Software are outlined, the first applications at COREM’s member plants are presented and, finally, future developments are discussed."

Jan 1, 2002

By Adil Aledresse, N. Emre Altun, Bern Klein, Nuri Hmidi, Brent Hilscher

A study was conducted to investigate high gold grades in water lines and carbon fines collected from the Musselwhite gold recovery circuit. It was discovered that fine magnetic particles in the overflow from the carbon fines settling tank launder had high gold grades ranging from 2,000 to7,000 g/t. The -37 micron fraction had up to 17,000 g/t gold. Scanning electron microscopy revealed the gold was attached to the surface of iron particles. The objective of the study was to identify possible mechanisms that result in the attachment of the gold to the magnetic iron particle surface and to recommend process modifications that would reduce these types of gold losses around the carbon circuits. Solid and solution samples were collected from the gold recovery circuit and analysed. Two possible mechanisms were identified including gold cementation onto iron and heterocoagulation of colloidal gold onto iron oxides in the elution column. Possible sources of the colloidal gold include reduction of gold cyanide complex to metallic gold in the carbon regeneration kiln and gold detached from cathode in EW cell. Based on SEM+EDX, the sources of iron were natural magnetite and roasted iron sulphides. Thermal reduction of gold is believed to be the cause of dendritic gold from the carbon regeneration kiln.

Jan 1, 2014

By Fred G. Hewett

The Cassiar orebody is located in a sill-like serpentinite body intrusive into the Devonian-Mississippian sedimentary rocks of northern British Columbia. Subsequent intrusion of the Cassiar batholith formed the McDame synclinorium and produced chrysotile asbestos. Present information indicates an orebody of approximately 16,277,000 tons amenable to open-pit mining, but continued diamond drilling will be needed to accurately define total tonnage and grade. A program has been developed at the mine to provide the required information on a daily basis, and work is continuing on more effective dollar-value prediction methods.

Jan 1, 1978

By H. C. Gunning

Introduction Considerable attention has of late been attracted to the area surrounding Nimpkish lake, on northern Vancouver island, by the discovery of important rich copper deposits. In less than two years some 200 mineral claims have been staked in a small area, and at least two groups have very promising surface showings. During the summer of 1929, the writer spent one month investigating the general geology and mineral deposits of the region, and, although no detailed work has as yet been done in the field or in the laboratory, the importance of the mineral discoveries and the lack of geological information available to the public warrants a preliminary paper on the district. The district is, from a mining viewpoint, very accessible. Boats from Vancouver call at Englewood, in Beaver cove, four times a week. From Englewood, a first-class logging railway, operated by the Wood, .English Company, extends to the northeast corner of Nimpkish lake. The fifteen-mile trip from the north to the south end of the lake is made by boat, two tugs being maintained by the logging company. The whole trip from Englewood can easily be made in one day. The known mineral deposits lie immediately east of the southern part of the lake, four miles or less from the shore. A fair trail, four miles ? long, leads from the lake to the Nimpkish Copper group. Apart from this trail and an old logging railway grade which follows the east side of Klaanch river for several miles, no trails exist on the southeast side of the lake.

Jan 1, 1930

By Gordon Jackson

"There are two accomplishments of air and gas drilling: a new series of economic and mechanical challenges; and, acceptance as a standard drilling and completion tool.The new challenges are related to the concept of using a gaseous circulating medium in drilling for oil or gas. For purposes of discussion, a two part division has been made: the challenge of fluid invasion control and that of equipment and tools. Great strides have been made in the development of materials and techniques to combat formation fluid invasion. Chemicals and the ""mist drilling"" technique, now in use, have the versatility to cope with a wide range of downhole fluid entry conditions.Equipment and tools have been developed to meet the challenges of better, more economic drilling and completion possible with a gaseous circulating fluid. Economic and operational challenges remain.Acceptance of air and gas drilling as a normal operating tool was reached with difficulty. It is now established as a means of reducing costs in exploratory and develop-mental well drilling, exemplified in a recent study of 226 wells covering 419,407 feet of hole in the United States. Air reached the projected depth in 85 per cent of the operations, although formation water was encountered in 48.7 per cent of the holes. Slim hole bit performance and cost all compared for overall bit averages as part of analysis."

Jan 1, 1961

"THE PACIFIC CONTINENTAL MARGIN OF CANADA is de-fined, for the purposes of this paper, as the area sea-ward from the present mainland coast of British Columbia to the foot of the continental slope. It thus coincides with A. Sutherland Brown's Insular Tectonic Belt. The region is limited to the north and south by the political boundary with the U.S.A., the location of which is still in dispute.The region can be subdivided into: (1) an interior trough comprising the Queen Char-lotte, Comox and Nanaimo basins; (2) a medial uplift comprising Vancouver Island and the Queen Charlotte Islands; and (3) a marginal shelf which is extremely narrow (Jess than 5 km) west of the Queen Charlotte Islands, widens to 160 km in Queen Charlotte Sound and is about 35 km wide west of Vancouver Island, where it is underlain by the Tofino sedimentary basin, with its• extension, the Juan de Fuca Basin, at the southern end.The medial uplift consists of a highly disturbed anticlinorium of mainly Mesozoic rocks, with a core of Palaeozoic. The rocks include thick sequences of eugeosynclinal volcanics and sediments. There is strati-graphical evidence of repeated interruption in sedi-mentation. By late Jurassic, the main eugeosynclinal phase was over and a successor basin was initiated in the interior' trough. This became filled, during Cre-taceous and Tertiary time, with sediments ranging in environment from bathyal turbidites to terrestrial conglomerates and coals. West of the medial uplift, another successor basin developed in early Tertiary times and became filled with mainly deep-water marine sediments. A third effusive sequence marks the base of the Tertiary on Graham Island and over most of the Hecate Strait region and Tofino Basin."

Jan 1, 1970

By D. Allan Coutts

Demonstration projects using hydrogen as a fuel are becoming very common. Often these projects rely on project-specific risk evaluations to support project safety decisions. This is necessary because regulations, codes, and standards (hereafter referred to as standards) are just being developed. This paper will review some of the approaches being used in these evolving standards, and techniques which demonstration projects can implement to bridge the gap between current requirements and stakeholder desires. Many of the evolving standards for hydrogen-fuel use performance-based language, which establishes minimum performance and safety objectives, as compared with prescriptive-based language that prescribes specific design solutions. This is being done for several reasons including: (1) concern that establishing specific design solutions too early will stifle invention, (2) sparse performance data necessary to support selection of design approaches, and (3) a risk-adverse public which is unwilling to accept losses that were incurred in developing previous prescriptive design standards. The evolving standards often contain words such as: ?The manufacturer shall implement the measures and provide the information necessary to minimize the risk of endangering a person?s safety or health.? This typically implies that the manufacturer or project manager must produce and document an acceptable level of risk. If accomplished using comprehensive and systematic process the demonstration project risk assessment can ease the transition to widespread commercialization. An approach to adequately evaluate and document the safety risk will be presented.

May 1, 2007

By M. L. Jeremic

Altered and unaltered coal from the Star-Key Mine near Edmonton, Alberta has been tested under compression and under tension. The test results showed that altered coal samples have an appreciably lower strength than unaltered coal. Altered coal samples do not give a linear load-displacement curve, peak strengths are poorly defined and yielding is observed over a range of loads, so the material can be regarded as relatively plastic. However, unaltered coal samples produce a linear loading curve with a high tangential modulus and an easily distinguished peak strength at which there is a sudden brittle failure. These findings lead to important differences in the theoretical design of ribs and pillars in underground mines in the two coal types. The substantial differences in the strength properties and behaviour of the two types of coal are governed by a higher intensity of cracks in the weathered coal. Two causes of the additional cracking can be suggested-subaerial weathering and subterranean weathering of the coal.

Jan 1, 1979

By R. S. McCaffrey

In addition to its importance in agricultural production, Wisconsin is a very large manufacturing state and its rank in the metal working industries is probably first among the States of the Union per unit of population. The University of Wisconsin is a state supported institution and the Wisconsin tradition has always emphasized the relation of the University to the state and its responsibility to exercise its leader-ship where it might, in any and every way, for the development and benefit of the state and the community. The Department of Metallurgy of the University realized its responsibilities in the carrying out of the co-operative tradition and, two' years ago, an experiment was started in co-operative research between the University and certain of the industrial plants of the state. At the present time this work has so far progressed that it is no longer an experiment, and its results prove that this co-operative research may be carried on very advantageously and that, under the conditions existing in the state, the method employed has been satisfactory.

Jan 1, 1926