Search Documents

By O. Moselhi

Material can be seen as the fuel needed to execute the project from inception to completion. Material installed provides good indicators of progress achieved onsite vis-a-vis project schedule performance. It correlates well with the role of the schedule performance index (SPI) of the earned value method (EVM). Material is recognized to have a significant impact on achieved progress for physical completion of project activities. This paper presents a study on the development of material status index (MSI) in support of the EVM. Unlike the SPI, the newly developed index account for the criticality of project activities. This is carried out considering the total float of each activity, percent float (i.e. the ratio of float to activity duration) and the total float of the path on which the activity is located. MSI, can independently and jointly with SPI provide root causes behind problems encountered during project execution. In turn MSI can reveal material related factors behind the performance detected by joint interpretation of the two indices. MSI serves to provide added value in alerting management to take corrective actions. While SPI and MSI may have different values, they can jointly augment and enrich the captured project status based on EVM. To demonstrate the capabilities of the developed MSI method, it is implemented on a case study. The case encompasses the construction schedule of a hydro power station constructed in northern Quebec. Different scenarios are adapted from the real case to demonstrate a set of practical aspects of the developed index. The results generated from the analysis of the case study illustrate the useful features of MSI beyond those of the traditional SPI on two fronts; causation and the considerations of criticalities of actives.

Aug 1, 2013

By Karl J. C. Harries

This paper looks briefly at some of the agreements and types of royalties that may be met during exploration activities, but does not go into details relating to them. Agreements can either make or break a deal or relationship. A well drafted, comprehensive and fair agreement can create good relations and trust among the parties and will go a long way towards making a deal work. In the best of all worlds the agreement will be put away and not need to be referred to after it has been signed (but it will be there if needed to sort out potential problems). On the other hand, a poorly drafted agreement or one that is inappropriate to the circumstances or unfair to one of the parties can break a deal and end up with the parties facing each other in that expensive, unproductive and time-consuming occupation ? a lawsuit. Accordingly, it is advisable to involve professional advisers with any agreement. The straightforward one may involve no more that a read through whereas the more complex agreement will require considerable involvement. There is, however, one rule for every explorationist to remember: a professional adviser is only an adviser. His responsibility is to make sure that you have the necessary information to make a reasoned decision but the decision is yours, not the adviser?s. It is your deal, you are going to have to live with it, and it is inappropriate for an adviser to introduce new concepts or amend negotiated ones without your specific instructions. Mineral exploration agreements, although basically option, acquisition and joint participation agreements, come in all the shapes and forms, appropriate to give effect to the endless variety of deals negotiated by the ever-active minds of explorationists. You will note the reference to "joint participation agreements" rather than "joint venture agreements". The latter term was purposely avoided because, with the current activity of explorationists from common law jurisdictions in civil law jurisdictions, it has become necessary for the explorationist to become familiar with corporations and shareholders agreements. As most of you are no doubt aware, under the civil law system a joint venture is normally not recognized as a legal entity and, therefore, joint participation in projects is usually by way of corporations.

May 1, 2003

By B. Panton, J. Carvalho, E. T. Brown

"A major consideration in the design of high capacity tiedown anchors for dam, bridge and tower foundations is the tensile resistance of the rock mass to pullout, typically as a result of overturning moments or hydrostatic uplift. Rock mass pullout capacity for installed anchors is developed from the tensile strength and fracture propagation properties of intact rock, the orientation and physical properties of the discontinuities and anchor confinement at depth. The typically assumed, but generally conservative, design approach is to calculate anchor pullout capacity using the dead weight of a uniformly shaped inverted “cone” with an assumed initiation point and breakout angle. In some cases, some tensile or shear strength is considered across the area of the assumed pullout cone, however, these strength estimates are based primarily on based on limited historic testing data, empirical relationships for rock mass strength developed for other applications, and engineering judgement.As an alternative to the current foundation anchor design method, this paper presents a new approach to the rock cone pullout problem using Discrete Fracture Networks (DFN) combined with numerical simulations. The simulations presented in the paper investigate the influence of fractures in a synthetic rock mass on ultimate anchor strength. In addition, the global influence on fracture network statistics on rock mass pullout failure is also discussed and it is contended that some of the aleatory and epistemic uncertainty inherent in the design of rock anchors can be reduced by considering fracture statistics in anchor design."

Jan 1, 2015

By Pierre Sauvé, Alex Makila

"The Camflo stock of porphyritic quartz syenite is an irregular pipe-like body 200 metres in diameter injected along the axial plane of an E-W trending F2 fold, near the contact between the. Kewagama and Malartic groups. The stock plunges 55° to the NE, almost parallel to the fold axis. The stock, exhibiting pervasive, weak cataclasis with numerous, locally auriferous quartz veinlets, is cut by minor faults striking WNW and dipping about 45°NE.Two types of gold ore are distinguished at Camflo: ""porphyry"" ore and ""fault zone"" ore. ""Porphyry"" ore, accounting for 90% of the gold produced, forms wide zones within the stock. The zones are irregular in shape but tend to be oriented E-W in plan view (on a horizontal plane) and are elongated paraliel to the plunge of the stock. These zones are more abundant in the northern part of the stock. Differences between ore and barren porphyry are not obvious. ""Fault zone"" ore occurs outside the stock along minor faults, particularly in differentiated sills offer rodiorite and felsic granophyre. Gold grade is roughly proportional to the pyrite content which in turns depends in part on the original magnetite content of the host rock. Although both types of ore show some correlation between Au and S, the Au/S ratio is considerably higher in porphyry ore.The bulk of the gold is in quartz syenite and in felsic granophyre, the most brittle lithologies at the mine. Presumably, the vertically continuous, pipe-like stock, made up of shattered rock, provided the main channelway for the ascending mineralizing solutions."

Jan 1, 1990

By Franc R. Joubin, Donald H. James

"THE PROPERTY of Rexspar Uranium and Metals Mining Co. Limited is situated within 3 miles of Birch Island, British Columbia, a village on the C.N.R. main line 80 miles north of Kamloops. The claims extend up the south slope of the North Thompson River valley.Prospecting in the area dates back many years. Fluorite was reported in 1918, lead showings in 1926, and bog manganese in 1929. Diamond drilling in 1942-43 indicated more than a million tons of material containing 20 per cent fluorite and 15 per cent celestite in what is known as the 'fluorite zone'. Marketing and beneficiation difficulties have delayed further development of this deposit.Systematic checking of specimens and drill core by the B.C. Department of Mines and the Geological Survey of Canada revealed low radio-activity in the fluorite zone material. Subsequent prospecting with Geiger counters revealed zones of higher radioactivity a few hundred feet distant from the fluorite zone. The property at this stage came under the development direction of Technical Mine Consultants Limited, who undertook a program of diamond drilling. Of the several radioactive zones located, two have so far rewarded development and appear to constitute low-grade uranium orebodies. These are referred to as the ""Black Diamond"" or ""BD"", and the ""A"" zones -see section. Open-pit mining of the thick, dip-slope orebodies appears possible.General GeologyWalker (1) describes the local rocks as metamorphosed sediments cut by granodioritic intrusives and by greens tone. At the property the sequence is:GreenstoneUnconformity or intrusive contact Trachytic member -tuffs, breccia, flows. Argillite -black, thin, not always present. Schist -thin-bedded sericitic quartzite and siltstone with some calcareous layers."

Jan 1, 1949

By Henry C. Knight

A number of improvements in the techniques of budgetary control have been developed in the 1970's. The most significant of these is zero-base budgeting. This procedure is a marked improvement, because it overcomes some of the key weaknesses inherent in most traditional approaches to budgeting. It incorporates techniques and disciplines which improve the quality of both the budgeting effort itself and the documents that most senior managers will need to evaluate. The end result is a budget that establishes and improves cost effectiveness. This budget is based on resource allocations using cost-benefit criteria and on a system of prioritization for making funding choices. Zero-base budgeting is applied only to costs and expenses that are not conducive to control using industrial engineered standards. Therefore, the benefits attributed to zero-base budgeting will only hold true for administrative, selling, exploration, safety, fire protection and overhead, and other indirect types of costs and expenses. It is in this context that the question of its attractiveness for the mining industry is dealt with.

Jan 1, 1978

By J. Kouam

Al-Si-Cu and Al-Si-Mg alloys are widely used in several applications. Although they can be produced near-net-shapes, products made of these alloys very often require some machining. The purpose of this study is to evaluate the machinability of A319 and A356 under TO and T6 conditions. The machinability was assessed using during dry drilling machining process and the machinability indexes used are the chip form, the chip breakability and the cutting forces. It is found that 319 and 356 exhibit different machinability behaviors, especially in the T6-condition in terms of forces requirements, chip breakability and chip segmentation. It is also found that both the microstructure of the workpiece materials and the machining conditions significantly affect the chip formation mechanism, and therefore, the machining parameters could be selected to promote a chip form that is easily manageable in production.

Jan 1, 2011

By S. Ivanova

The results presented in this paper show that the gold solution dilution is a key parameter to control the dispersion of gold on ?-Al2O3 the selected support. The variation of concentration leads to changes in pH which modify the nature of gold complexes from HAuCl4 formed in the solution. These complexes are presented. Some of them (AuCl3(OH)- and AuCl2(OH)2 -) react with the surface of alumina and give interesting interaction. AuCl2(OH)2 complex has been considered as an ideal complex because of the strong anchorage of a bidentate species on the alumina. This complex is formed mainly in a solution of gold with a concentration of 10-4 M giving a pH of 3.5-4.5. The nature of the anchorage and the amount of chlorine, has an influence upon the formation of Au-Cl bridges which modify the dispersion of the gold on alumina of the final catalyst as shown by TEM.

Oct 1, 2003

By J. Mullins

Coal was first banked by the Dominion Coal Company, Limited, in 1898, near No. 2 Colliery, the same site as is presently used for that purpose. Though today there are banks at Glace Bay, Sydney, and Sydney Mines, these notes, except when otherwise desirable, will be confined to describing the practice as developed at the No. 2 Banking Station, Glace Bay, as being typical of methods obtaining at all sites. Storing The manner in which the coal was piled is illustrated diagrammatically in the accompanying sketch. A train of coal was brought on the main trestle, which extended the full length of the banking ground at a height of 22 to 39 feet above the natural surface, and dumped into bins which were integral with the trestle work. Chutes from these bins permitted the coal to be fed into 3-ton cars, which were horse drawn laterally on narrow gauge tracks laid about 10 ft. centres, to a maximum distance of 400ft. from the trestle. These cars were end-dump and as the pile extended laterally the narrow gauge tracks were lengthened by shorter or longer filling pieces, so that their ends were always kept at the brow of the bank. Much coal, however, had to be dumped directly on the tracks and hand trimmed to fill the valleys, and level off, between the tracks.

Jan 1, 1931

By Delio J-J Tortosa, Fred F. Langford

"The Cenex orebody occurs at the intersection of northwest and northeast-trending fault zones that formed during post-Hudsonian uplift. The ore is localized in breccia zones, along faults, and in veins and adjacent wallrocks. The host rocks are Tazin quartzo-fe/dspathic mylonites and ultramylonites and chloritesericite- quartz-graphite-feldspar mylonite schist. The uraniumbearing minerals are finely disseminated pitchblende and uraniferous titanate.The earliest mineralization may have been associated with /ate-stage retrograde metamorphism in the mylonite schist. The main stages of mineralization were associated with brecciation, hematization, carbonatization, and chloritization of the mylonites and ultramylonites. Uranium mineralization was clearly much later than any igneous or metamorphic activity associated with the Hudsonian orogeny.Late post-orogenic uplift, erosion, and deposition of the Martin continental clastics in fault basins were coeval with uranium mineralization. The deposit is consistent with a meteoric-hydrologic system constituting a source for orebearing fluids, hence the close spatial relationship of the uranium deposits in the Beaverlodge area with the basal unconformity of the Martin Group."

Jan 1, 1986

By B. Crane, S. Schwartz

"IntroductionThe Cape Breton Development Corporation (CBDC) located in Cape Breton, Nova Scotia, in eastern Canada, was established in 1967. Its mandate at that time was to facilitate a phased downsizing of the coal industry and developing viable replacement industries. The oil crisis in the early 1970s changed CBDC’s mandate and focus was modified to increase coal production to support Nova Scotia Power Commission’s “off oil” policy for their power generators. In the late 1980s the mandate to develop viable replacement industries was eliminated and CBDC became primarily a coal mining company. CBDC presently operates two underground coal mines, Phalen Colliery and Prince Colliery, using a retreat longwall method of mining. Both mines operate beneath the Atlantic Ocean. CBDC also operates associated infrastructure — central workshops, a railroad, coal preparation plant, and international pier. The Need For Substantial ChangeOver the last few years, CBDC has been facing some challenging issues, including improving labour management relations and achieving financial self-sufficiency and profitability. Recent achievements with regard to human resource issues, especially in the areas of collective bargaining, absenteeism, and attendance, show noticeable improvements. All participants should be commended for successfully concluding the collective bargaining process with all four CBDC unions, CUPE; CAW; IAM&AW; and UMWA. However, although these changes are encouraging, even critical in the short term, they are not sufficient to ensure the long-term viability of the company. Market ForcesShort- and long-term financial realities are drawing the need for further substantive changes. The corporation has a mandate to achieve financial self-sufficiency by the year 1999. This goal can only be achieved through a combination of cost reductions and productivity gains, specifically, a reduction in the workforce of 658 and an increase in production of 800 000 tonnes annually. This increase in productivity requires CBDC to re-think the way it does things.In the longer term, CBDC faces even greater challenges. The energy market is becoming more competitive. The electrical utilities across Canada are anticipating deregulation and are positioning themselves for the resultant competition. As primary fuel supplier to Nova Scotia Power Inc. (NSPI), the corporation will have to become ever more competitive to stay in business."

Jan 1, 1997

By Shanjun Mao

This paper summarizes current achievements of Digital Mining in China, puts forward the concept, framework and key technology of Smarter Mining, and finally points out that there is still a long way to go in order to acheive Smarter mining.

Aug 1, 2013

By Dong-Hyeun Koh, Yun-Soo Lee, Min-Seok Kim, Hyoung-Wook Kim

High strength AA7068 (Al - 7.88 wt.% Zn - 2.68 wt.% Mg - 2.07 wt.% Cu) aluminum alloy strip was successfully fabricated by horizontal-type twin roll casting. A simulation technique was used to obtain the range of casting conditions for fabricating strip without defects. The cast strip with thickness of about 5 mm was hot rolled, intermediate annealed, cold rolled to final thickness and subsequently annealed at various temperatures. Tensile properties of annealed and the aged specimens were evaluated at ambient temperature. Tensile strength and elongation of the annealed sheet are about 365 MPa and 28%, respectively. Also, the tensile and yield strength after the aging at paint baking condition (180 °C x 0.5 h) are 586 MPa and 551 MPa, respectively. Therefore, it is expected to show good formability prior to press or stamping and also provide high dent resistance after paint baking treatment.

Jan 1, 2015

By Daniel Cluff

Frozen backfill for mining operations in permafrost must be delivered in such a state so as not to thermally impose on the host rock surrounding the filled stope. The placement process, the material strength demand, and the freezing time delay are the parameters that control the applicability of the method. A two-year research program was carried out in the field and using a laboratory-scale apparatus, designed to simulate a pour of frozen backfill, to study the mixing, thermal properties and segregation. The frozen rock and tailings must be at a below zero temperature and get fully wetted so the surfaces cause adherence of the particles to one another and enhance the solidification of the poured backfill. The results provided a recipe and a process for mix design for open stoping operations in cold regions. The testing evaluated the sensitivity of the test parameters that included the amount of water added in the mix, the temperare of water, the rockfill/tailings ratio, and the temperature of solid constituents.The paper presents the result of this environmentally friendly, innovative technology. The distribution of the materials and the mixing process are instrumental in achieving the properties required for open stoping applications.

Oct 1, 2010

By D. Sediako

Excessive residual stress in Al engine blocks may result in cylinder distortion which reduces engine operating efficiency. As such, neutron diffraction was used to measure residual strain along the Fe liners and Al, in the hoop, radial and axial orientations with respect to the cylinder axis, at the cylinder interbore region. Residual stresses were subsequently calculated using generalized Hooke's law and related to the microstructure along the cylinder bridge. The results suggest that the residual stresses in the Al interbore region are tensile and increased with depth in the axial direction of the cylinder. The increase in residual stress at the bottom of the cylinder coincides with a finer and more uniform microstructure in this region of the cylinder. The refinement in microstructure at the bottom of the cylinder likely increased alloy strength, thereby decreasing this section's susceptibility to distortion. This study successfully quantified the residual stress profiles in a heat treated engine block and related the stress profiles to an as-cast engine block.

Jan 1, 2011

By Q. Han

Irradiation of high energy ultrasonic vibration in metals and alloys generates oscillating strain and stress fields in solids, and introduces nonlinear effects such as cavitation, acoustic streaming, and radiation pressure in molten materials. These nonlinear effects can be utilized to assist conventional material processing processes. This article describes recent research at Oak Ridge National Labs (ORNL) and Purdue University on using high intensity ultrasonic vibrations for degassing molten aluminum, processing particulate reinforced metal matrix composites, refining metals and alloys during solidification process, welding, and producing bulk nanostructures in solid metals and alloys.

Jan 1, 2014

By T. G. Joseph, A. Sharma

ABSTRACT: Ultra-class haul trucks operating in oil sand face operational and maintenance issues as a result of soft underfoot conditions (Joseph, 2002). With exposure to frequent high g loading events, tire life is reduced due to sidewall belt fexure and frequent ground contact. Therefore, an improved under-standing of the interaction between tires and oil sand is needed. This paper examines the outcomes of a series of static and cyclic loading tests, performed using a scale tire on rigid, sand, and oil sand surfaces. Geometric predictions are made regarding the footprint area and vertical deformation of an ultra-classtire on similar surfaces.

Jan 1, 2011

By J. R. Meyer, P. L. Dean

"The Department of Mines and Energy is at present investigating the dimension-stone potential of the Nain anorthosite complex. These rocks are known to host occurrences of labradorite, a semiprecious gemstone known for its beautiful play of colours (chatoyance). Test blocks that contain 5% to 18% chatoyant labradorite were extracted from three prospects south of Nain. These have been slabbed and polished for further evaluation.Second-grade labradorite stockpiled around the Grenfell quarry on Tabor Island is also being evaluated as a potential source of aggregate for use in terrazzo tiles, precast concrete and epoxy-backed wall panels.IntroductionThe Nain anorthosite complex consists of approximately 10000 km2 of anorthosite and related basic rocks , which are well exposed along the coast of Northern Labrador (Fig. 1) (Emslie et al., 1972). These rocks have been known for centuries to host deposits of gem-quality labradorite. The chatoyant nature (i.e. the play of colours or labradorescence) of this semiprecious feldspar has been utilized mostly in the making of jewelry and other polished, handcrafted products. In the early sixties, Brinex Limited (now Brinco Limited) attempted larger scale commercial exploitation of labradorite, including use 'as building stone and in polished precast concrete for facings on buildings' (Brummer, 1984). After six years of work, which included market studies, Brinex decided that, at that time, the demand did not warrant further production.In recent years, there has been a dramatic increase in the markets for dimension-stone. In the period from 1980 to 1985, the demand in the United States for granite, much of which is imported, has increased 1735070 (Marble Institute of America, 1986). The dimension-stone industry's remarkable growth rate has, in part, resulted from new technology that makes it easier and faster to quarry and cut stone. This has allowed natural storie to compete with other building materials. Now, it is not only used for exterior cladding and walkways, but also on interior walls and floors, and in home and office furnishings, such as countertops for kitchens and bathrooms, table and desk tops, stairways, window sills, and fireplaces."

Jan 1, 1988

By J. R. Meyer, P. L. Dean

"The Department of Mines and Energy is at present investigating the dimension-stone potential of the Nain anorthosite complex. These rocks are known to host occurrences of labradorite, a semiprecious gemstone known for its beautiful play of colours (chatoyance). Test blocks that contain 5% to 18% chatoyant labradorite were extracted from three prospects south of Nain. These have been slabbed and polished for further evaluation.Second-grade labradorite stockpiled around the Grenfell quarry on Tabor Island is also being evaluated as a potential source of aggregate for use in terrazzo tiles, precast concrete and epoxy-backed wall panels.IntroductionThe Nain anorthosite complex consists of approximately 10000 km2 of anorthosite and related basic rocks , which are well exposed along the coast of Northern Labrador (Fig. 1) (Emslie et al., 1972). These rocks have been known for centuries to host deposits of gem-quality labradorite. The chatoyant nature (i.e. the play of colours or labradorescence) of this semiprecious feldspar has been utilized mostly in the making of jewelry and other polished, handcrafted products. In the early sixties, Brinex Limited (now Brinco Limited) attempted larger scale commercial exploitation of labradorite, including use 'as building stone and in polished precast concrete for facings on buildings' (Brummer, 1984). After six years of work, which included market studies, Brinex decided that, at that time, the demand did not warrant further production.In recent years, there has been a dramatic increase in the markets for dimension-stone. In the period from 1980 to 1985, the demand in the United States for granite, much of which is imported, has increased 1735070 (Marble Institute of America, 1986). The dimension-stone industry's remarkable growth rate has, in part, resulted from new technology that makes it easier and faster to quarry and cut stone. This has allowed natural storie to compete with other building materials. Now, it is not only used for exterior cladding and walkways, but also on interior walls and floors, and in home and office furnishings, such as countertops for kitchens and bathrooms, table and desk tops, stairways, window sills, and fireplaces."

Jan 1, 1988

By Nicholas Bonderoff, Amily Xu

The evaluation of battery electric vehicles (BEVs) in underground mines involves comprehensive business case analysis beyond just the capital and operating costs of the equipment itself. BEVs demonstrate benefits from an EHS perspective, reduced mine ventilation costs, lower energy operating costs, reduced overall GHG emissions (dependent on the source of electricity), elimination of DPM, lower equipment maintenance costs, and reduced cooling requirements in deep mines. When including batteries and supporting infrastructure, BEV capital costs are approx. 80% greater than that of diesel equipment. The project economics are highly dependent on the cost of electricity and diesel fuel, and these can vary widely depending on the location of the mining operation. Battery charging and swapping methodologies must be evaluated as there are a variety of approaches that can be employed which vary by manufacturer and type of equipment. Careful consideration of the cycle times, charging methodologies, and location of the battery charging infrastructure is necessary. Specific operating conditions must also be taken into consideration. For example, the time for blast gases to clear will be increased by reducing ventilation flow, and the potential impact on production needs to be evaluated. Similarly, the electrical distribution system needs to be evaluated for peak loading conditions when BEVs are charging. Criteria including maintainability, reliability, commercial availability, and performance need to be evaluated. BEVs have fewer components than diesel equipment and this correlates to lower overall maintenance costs, however, BEVs require maintenance personnel with specific skill sets in order to maintain the equipment. Battery lifecycle costs need to be considered as battery replacement incurs significant capital expense. Some manufacturers offer services to offset these capital costs through usage agreements. Recycling and disposal of batteries at the end of their lifecycles also need to be considered. With the increased selection of BEV equipment that will be available in the next 2-4 years, 100% BEV adoption is also possible. We recommend a holistic approach when evaluating BEVs for underground mines. This will ensure that everything is considered in order to evaluate the full impact of BEV implementation.

Jan 1, 2023