Search Documents

By Greg Yuriy

This paper discusses research carried out by the Laurentian University Mining Automation Laboratory (LUMAL) in the field of discrete-event simulation of mine equipment systems and reliability assessment of these machinery using genetic algorithms. The AutoMod simulation package, from Brooks-PRI Automation Inc., is used in this research. It is a 3-D discrete-event simulation/animation software tool for creating realistic depictions of manufacturing and materials handling systems. Discrete-event simulation involves modeling of real-life systems based on variables and events which occur or change at distinct points in time. In our case, a two level, multi-drift sublevel stoping model was created in AutoMod for the simulation of the equipment fleet employed in the development cycle (drilling, explosives loading, blasting, materials hauling, ground support) of a typical underground mine in the nickel mining region of Sudbury in Ontario, Canada. The equipment primarily considered in the simulation is Load-Haul-Dump (LHD) vehicles (scooptrams), drills, explosives-loaders and roof bolters. The purpose of the simulation study is to assess the impact of equipment failures to mine?s production throughput. In more detail, using Mean Time Between Failures (MTBF) data of scooptrams derived from a reliability assessment model based on genetic algorithms, LHD failures are incorporated into the simulation model. These failures cause production interruptions to the development cycle and consequently loss of hauling capacity. This paper will indicate the significance of equipment failures to a mine?s production and suggest a methodology based on the combination of discrete-event simulation and a predictive reliability assessment model using genetic algorithms for the study and analysis of mine equipment systems.

May 1, 2003

By David Penswick

Despite anecdotal evidence to the contrary, the mining industry is not in decline. Rather, the world?s largest mining companies are among the most consistently profitable companies in any industry. In many cases, profitable mining companies have been built around a few large scale, long life mines. These criteria for success ? size and long life ? have led to the current preference for deposits that can be exploited using open pit methods. However, developments in the science of block caving have resulted in this mining method achieving costs and productivities that are competitive with the largest open pits, while achieving widespread applicability. One implication of the low costs and widespread applicability of block caving is that some current open pits are possibly too deep.

May 1, 2003

By S. Goodman

Successful exploration for and exploitation of a mineral deposit requires an accurate understanding of the deposit architecture in 3D, and of the development of the mineralizing system through time, which requires a thorough comprehension of the structural framework of the deposit. The integration of geological, geophysical and geochemical datasets to arrive at a 4D structural framework is well-established and has been successfully applied by SRK Consulting in projects from deposit to regional scale. In some cases, we can go beyond this, applying the SEEBASETM technique, which utilizes a ?bottom-up? approach to basin analysis. SRK?s approach primarily relies on the interpretation of magnetic and gravity data, calibrated with many other datasets including mapped geology, topography, event histories, wells/drillholes and seismic data. The SEEBASETM model is a culmination of this data integration and is produced through an iterative process of structural interpretation and geophysical modeling, where an interpretation of basement composition and 4D structure is used to constrain depth-to-basement geophysical modeling, and the modeled depths are then used in conjunction with the structural interpretation to constrain contouring of the basement topography. The result is a rigorously calibrated, 3D view of the basement surface, which can be used to understand the basement and basin architecture, and thus serves as a predictive exploration model. This technique, which was developed for use in the petroleum industry, is now finding success as a predictive tool in mineral exploration.

May 1, 2003

The following guidelines have been recommended by the Diamond Exploration Best Practices Committee established by the Canadian Institute of Mining, Metallurgy and Petroleum. These guidelines are applicable to public companies and their consultants reporting diamond exploration results. In respect of these guidelines, Diamond Exploration Results are results derived from the initial activities undertaken to investigate a diamond bearing prospect or deposit, to generate tonnage, grade and value estimates that cannot be classified as a Mineral Resource or Mineral Reserve. They do not address the earlier stage reporting of geophysical, geochemical or kimberlite indicator mineral results. Public reports of Diamond Exploration Results relating to mineralization not classified as Mineral Resource or Mineral Reserve must address the confidence limits of the result and contain sufficient information to allow a considered and balanced judgement of the significance of the results. The objective of these guidelines is to assist public companies and consultants in making appropriate disclosure of diamond exploration results by reporting in a manner which is: ??Uniform within the diamond exploration industry; ??Consistent with reporting from other industry sectors; ??Comprehensive; ??Unambiguous. The guidelines are not prescriptive. Materiality is the overriding principle that determines the information that should be disclosed. However, where a company or consultant deviates from the guidelines, the disclosure or technical report should state the extent to which the guidelines have not been followed, and the reasons for the deviation. The guidelines do not in any way replace jurisdictional reporting requirements (For example, the requirement for Canadian reporting issuers to comply with Canadian Securities Administrators National Instrument 43-101 by having technical disclosure endorsed by a Qualified Person as defined in that legislation).

May 1, 2003

By Andrew Abraham

Continual improvement is the key to success in today?s competitive global arena. You require tools that promote dynamic quality management, deliver cost savings to your bottom line and provide the foundation for process improvement. ISO 9000 and ISO 14001 management systems and OHSAS 18001 are those tools. Since their inception, the benefits of ISO management systems and registration have been touted as the way to achieve better bottom line results. This spurred many companies to embark upon the road to registration with high expectations. The potential benefits of ISO management system implementation and third party registration that are commonly provided by Registrars and consultants are compelling adverts for success. ISO 9001:2000 is promoted as an essential tool for systematic efficient and affective management controls that provide a framework for analyzing errors and improving a company?s internal operational processes. It also allows companies to comply with internal and external customer and regulatory requirements thus continually improving the quality of their products and services and thus enhancing customer satisfaction. This, in turn, leads to greater customer recognition and increased market share. ISO 14001 implementation and registration may assist your company in reducing its litigation risk, raw material and energy consumption, waste disposal costs and possibly non tariff trade barriers. It should also provide continuity of operations, enhanced operational efficiency and consequently a competitive advantage in the market place. Registration of your ISO 14001 management system should also improve your company?s profile and credibility leading to regulatory flexibility and improved community goodwill. All of this will be a catalyst for improved morale and pride by employees and management alike. Likewise, OHSAS 18001, the latest certification specification for Occupational Health and Safety Management Systems supports Occupational Health and Safety legal and regulatory obligations and compliance, manages & controls Occupational Health and Safety risks and improves performance, safety culture and efficiency. OHSAS 18001 is an audit certification, and not a legislative requirement. Suggested benefits of implementation include reduction in accidents, lost time and associated liability and insurance costs and improving reputation and credibility through demonstrated commitment to health and safety. The foregoing increases access to new customers, joint venture partners and financing The skeptics say these are motherhood statements and lack corroborative evidence, i.e., ?Show me the money!?

May 1, 2003

By A. -M. Cadieux

During the geological synthesis of the Réservoir Pipmuacan area (NTS 22E) by the Ministère des Ressources naturelles (Québec), several ilmenite-apatite occurrences, some well-known and some recently discovered, have been examined. These occurrences are hosted in the Lac-Saint-Jean and Labrieville AMCG anorthositic suites. The Lac-Saint-Jean Anorthositic Suite (1160-1140 Ma), composed of multiple intrusions covering an extensive surface area, is characterized by labradorite plagioclase. The Labrieville Anorthositic Suite (1010-1008 Ma) is characterized by andesine plagioclase. It was previously known as the Labrieville Anorthosite, which was composed of a small isolated pluton located east of the Lac-Saint-Jean Anorthositic Suite. However, new geochronological data and field observations indicate that the Labrieville Anorthositic Suite in fact includes several intrusive bodies, namely the La Hache Monzonite and the Mattawa Anorthosite. A series of major structures (Saint-Fulgence, Pipmuacan, and Chute-des-Passes deformation zones) and their conjugate faults played an important role in the emplacement of the Lac-Saint-Jean Anorthositic Suite. The Saint-Fulgence deformation zone appears to have been involved in the emplacement of the Labrieville Anorthositic Suite. Oxide mineralizations are abundant in both anorthositic suites. Ilmenite, magnetite (± titaniferous), and apatite assemblages are found mostly in the labradorite-type anorthosites, while hemo-ilmenite, magnetite and apatite assemblages are associated only with the andesine-type anorthosites. Field works has revealed ilmenite-apatite mineralizations in a variety of settings, with grades reaching 48% TiO2, 16.2% P2O5, and 71.7% Fe2O3 (tot). Numerous oxide-bearing gabbronorites, often accompanied by or located near massive apatite-oxide accumulations (nelsonites), were discovered. Among these oxide-rich zones, breccia zones with anorthosite enclaves in an oxide matrix (ilmenite-magnetiteapatite) have been observed. Locally, ilmenite-apatite mineralization occurs as cumulate concentrations in ultramafic rocks. Evidence has been observed for immiscible magmas, for magmas differentiated from a mangerite or jotunite parent, and even for late magmas differentiated from the anorthosite magma itself (apatite-bearing anorthosite). Finally, the northern part of the Lac-Saint-Jean Anorthositic Suite hosts sulfide and vanadium mineralizations associated with ilmenite-apatite enriched zones, with grades reaching 1.48% Cu, 1.22% Ni, 1.6% Cr2O5, 0.25% Co, and 0.52% V2O5.

May 1, 2003

By Guy Chevalier

QCM?s pellet plant, located in Port-Cartier, Quebec, produces up to 8.6 million tons of iron ore pellets annually. Four different types are produced: three for blast furnace operations and one for direct reduction furnaces. The paper presents the scientific approach that led to the installation of new process equipment to improve the reducibility of direct reduction pellets (DR pellet). The findings, the equipment selection and some post start-up modifications are presented. This low silica DR pellet is used in Midrex and HyL shaft furnaces. A good DR pellet has to meet strict chemical, physical and metallurgical specifications. An important metallurgical property is its ability to release oxygen when exposed to reducing gases. Considering that the market for DR pellets is expanding and being aware that reducibility is critical for our clients, a program to improve the latter was undertaken. Test work showed that one factor which has a negative effect on reducibility is the proportion of particles larger than 75 microns. Knowing that the best way to reduce the amount of coarse particles was to close our open grinding circuits, we began evaluating the most suitable classification equipment applicable to our process operations. We settled on hydro-classifiers based on their very sharp cut and their low operating costs. In light of the hydro-classifiers performance it was also decided to replace the hydro-cyclones of an already closed circuit.

May 1, 2003

By Knud Sinding

Mining firms are widely criticised for their adverse impacts on the environment. At the same time many firms in the industry devote extensive resources, both financial and managerial, to the reduction or elimination such impacts. Very considerable improvements have been made, although these are sometimes overshadowed by a few high-profile accidents, such as the occasional collapse of a cyanide-containing tailings dam. In parallel, much effort is also directed at projecting a positive environmental image, as witnessed by extensive environmental reporting, both on paper and increasingly through web-platforms. Mining projects today almost invariably involve some form of environmental protection. In industrial countries regulations in this area are extremely stringent, as is enforcement. In less well developed countries, regulation and enforcement may be weaker, but firms are in many cases and for a number of reasons committing themselves to high levels of environmental protection, even if they might get away without doing so. Research in the area of environmental performance of mining firms has so far paid much attention to concepts such as sustainability indicators and the sustainability of individual firms. Given the still raging debates about the appropriate way to determine the degree to which any given firm is sustainable (Welford 1995) as well as the usefulness of what will in the final analysis be a value judgement, anyone on the sidelines of the debate will come back to the fundamental issue, how is knowledge that a particular firm has been judged ?sustainable? going to be made use of. This issue remains unresolved, which may explain the lack of progress in formulating a useful definition of a sustainable firm The question addressed in this paper is not so much about what firms are doing on the ground or in any particular case of environmental protection, but more in the subsequent use of these efforts - and by extension - on the overall direction of corporate environmental strategy. The fundamental problem facing all mining firms is that they cannot easily benefit from unilaterally reducing their environmental impact. The firm can of course avoid liability and keep a variety of stakeholders happy and hence experience lower costs of obtaining the [input] resources they need (in a broad sense, not just minerals), but this represents only part of the opportunities available form pursuing an environmental strategy (Reinhardt 2000). The other part, which may have an enormous potential, involves the concepts of competitor management and product differentiation. The logic of keeping stakeholders happy has been most forcefully argued by Pfeffer and Salanchick (1978) who link the behaviour of firms in all domains to their ability to obtain the resources they need, at a cost that is lower than it would otherwise be (Pfeffer & Salanccik 1978). Several varieties of strategy can be included under this heading, including cost reduction and risk management. The alternative logic is to convince customers that they want to pay more for minerals supplied by mining firm X or directly attributable to mine Y, or by making all mineral users pay more. These two strategies, which may be referred to as product differentiation and competitor management, respectively (Reinhardt 2000) are related to the demand side of mineral supply, whereas cost reduction and risk management are related to the supply side. Mining firms have not pursued the demand side very much, if at all. This is probably due to the extreme difficulty of moving mineral products, bulky and unglamorous as they are, away from their

May 1, 2003

By Kent Zehr

Suncor Energy Inc. is an integrated producer and refiner of oil and gas headquartered in Calgary, Alberta. The bulk of revenue comes from the Oil Sands Group (OSG) operating in the McMurray formation of the Athabasca Oil Sands. Located some 25 kilometers north of Fort McMurray, Suncor OSG began life in 1967 as Great Canadian Oil Sands, the first operator to successfully enter commercial production of synthetic crude oils from the area. For most of the last decade, dramatic growth has been the standard mode of operation for Suncor OSG. Production of synthetic crude first reached 100,000 barrels per day in 1997 and less than five years later is averaging in excess of 200,000 barrels per day. Within this dynamic organization, Suncor Extraction is the business unit that processes run-of-mine ore into clean diluted bitumen for Upgrader feedstock. Extraction also delivers and places the barren sand and process affected water into tailings storage in one of several ponds from which water is recycled to support the various processes. For reference purposes, Extraction on a typical day currently receives more than 400,000 metric tons of oilsand ore, which is all processed to water based slurry for separation in one of two extraction plants. Separated tailings are disposed of as a slurry and the cleaned bitumen froth is diluted with naphtha and sent to tankage for storage until required by the Upgrading Unit. As a consequence, on a typical day Suncor Extraction pumps more than 1,000,000 tonnes of aggressive slurry into and out of the two extraction plants.

May 1, 2003

By Robert Hamilton

Aur Resources is Canada's leading copper mining company with producing mines and development projects in North, Central, and South America. Copper production from Louvicourt Mine in Quebec, Quebrada Blanca, and Andacollo Mines in Chile had a record of 245 million pounds in 2001. Located 600 km North of Montreal, Louvicourt Mine is a joint venture between Aur Resources (30%), Teck Cominco (45%), and Novicourt (45%). Aur Resources is the mine operator with 280 employees working to produce a copper and zinc concentrate. In operation since 1994, the mine has produced a total of 12,606,000 metric tonnes of ore grading 3.6 % Cu, 1.5 % Zn, 26gr./m.t Ag, 0.9gr.m.t Au. This highly mechanized mine reached full production in August 1995 at 4,000 tpd. From 1996 to 2001, the average mine production rate was more than 4,300 tpd. The Louvicourt Mine continued its record of solid performance in 2002 and is expected to continue to do so for the balance of its 2.5 years mine life.

May 1, 2003

By Michael Samis

The real option valuation method is often presented as an alternative to the conventional discounted cash flow (DCF) approach because it is able to recognize additional project value due to the presence of management flexibility. However, these two valuation methods can be separated on a more fundamental level by their differences in risk discounting. Real option valuation applies the risk-adjustment to the source of uncertainty in the cash flow while the DCF method adjusts for risk at the aggregate level of net cash flow. This seemingly small difference is the reason why the real option method is able to differentiate between projects according to each project?s unique risk characteristics while the conventional DCF approach cannot. This paper provides an overview of the real options and DCF valuation frameworks and discusses the differences in risk discounting that exist between the two methods. Using grade-school mathematics, this paper clearly demonstrates how, with real options, a unique project risk discount can be calculated which is directly linked to the project?s unique risk profile. It also highlights why the DCF method fails in this regard and shows why a call to ?increase the Risk-Adjusted Discount Rate? is an incomplete solution at best. Finally, a heap-leach project and satellite reserve development project are valued with both techniques and the difference in investment conclusions is explained in terms of the risk-discounting concepts discussed here.

May 1, 2003

By Charles Tkaczuk

In order to remain competitive the mining industry must keep up with changes in technology. Many innovative technologies from the mining perspective are commonplace in other industries. A ?Global? review of technologies will often reveal existing technologies that can be innovatively applied in the mining industry. Industries, which are rife with proven solutions include, medicine, biotechnology, security, manufacturing, telecommunications, etc. This paper addresses the communications aspect of mining where greater productivity, lower costs and the ability to quickly react to mining related events is obtained through an increase in remote monitoring and operating control. A review of the communications systems in place globally reveals technologies that, with minimal modification, can be immediately applied to the mining environment. We discuss the concept, advantages and implementation of existing communications technology from an industry that is not usually associated with the mining industry. This technology will form the basis of a solid platform on which can be built a state-of-the-art process monitoring, control, and communication system. This lays the groundwork for providing one solution to the underground mining industry?s most difficult problem, establishing a reliable, maintainable and cost-effective underground bi-directional wired/wireless data, video and analog communications system. We need look no further than our own doorsteps to find such a solution. The cable that you see coming from the simple green or brown box on the boulevard into your home contains hundreds of television broadcast channels, FM radio channels and data channels. And if you have a set-top box, you are in control of it all. The Cable Television Broadcast Distribution System suppliers of today are at the leading edge of converging all the different methods of communications onto a common carrier, coaxial cable or fibre optic cable. There is no fundamental difference between providing a reliable communications network to a city/neighbourhood/home/personal computer than there is to a mining operation/underground level/equipment or person. The principle is the same. Only the application is different. Realizing this, we can capitalize on the efforts of other industrial sectors, to solve our communications problem. Where else can you find a solution to a problem that is mature, having been developed with the input of thousands of engineers, and having hundreds of millions of dollars spent on research and development, manufacturing, distribution, global presence and engineering support?

May 1, 2003

By Robert Shaw

"The paper point out the volcanogene and sediment-hosted base metal deposit from the Colombian cordilleras have been considered in the light of tectonogenic models for these deposit types, based upon the recent re-interpretation of the geology and tectonic assembly of the Northern Andean Block by Cediel and Cáceres and Cediel. Numerous distinct propitious metallogenic settings containing important but subexploredbase metal mineralisation are manifest as a result of the tectonic evolution of this northern-most sector of the Andes. Some examples include like a) Central African Cu (U) Belt - type mineralisation within the back-arc region of the early– middle Paleozoic Cordillerantype Quetame Orogeny, b) numerous SEDEX and Sediment-Hosted Zn (Pb-Ag) and Cu (Ag) styles of mineralisation associated with various phases of continental and continental margin rifting during the late Paleozoic to Mesozoic Bolívar Aulacogen, and c) various Cu-Zn-Pb (Au, Ag) Volcanogene Massive Sulphide manifestations associated with intra-oceanic magmatic arc development and accretionary tectonics during the Meso-Cenozoic Northern Andean Orogeny. "

Apr 22, 2003

By Eric Nelson

The paper point out the structural openings and the localization of ore bodies. Structural openings in rocks constitute the primary permeability network for the formation of most hydrothermal ore deposits. The distribution, geometry, density, and orientation of ore bodies in structural openings are controlled by two primary factors: the far and near field stresses and the mechanical properties of rock. When stress controls the orientation and kinematics of faults and fractures in the absence of pre-existing weaknesses, ore shoot orientation is perpendicular to the fault slip vector and can be predicted by kinematic analysis. However, when structural openings form along pre-existing weaknesses, ore shoot orientation cannot always be predicted by kinematic analysis. Because we can classify ore bodies based on the types of geological structures discussed above and the variations that naturally occur from material property heterogeneity, exploration for hydrothermal ore deposits should include analysis of geologic structure and evolution, rheological variations, pre-existing weakness, and fault kinematics to evaluate structuralcontrols on localization of ore bodies.

Apr 22, 2003

By Peter Yen

This session consists of five papers. Three involved research on the properties of grout materials, specifically ultrafine cements and polyurethane grouts. Two papers present the development of soil grouting technology and monitoring methods. Of great interest are the papers on ultrafine grout penetrability testing focusing on the pressure filtration effects encountered in permeation grouting applications (Ericksson, Stille and Mittag, Savidis). The comparison testing of hydrophilic and hydrophobic polyurethane grouts submitted by Vrignaud, Ballivy, Perret and Fernagu assessed the long-term performance of these materials for repairing saturated cracks in concrete, subject to thermal expansion and contraction. Two very practical papers present the development of soil grouting, where permeation, fracture, replacement, jetting and other grouting techniques are utilized. The papers by Lees with Chuaqui and Warner present experience with ultrafine and other commonly used grout materials. Methods to measure and monitor the injection process and verify production progress are discussed.

Feb 10, 2003

By Stephan A. Jefferis

I presume that the questioner is not asking about the reduction of sulfate in groundwater to hydrogen sulfide as a result of biological activity promoted by organics in the grout hardener and that the question relates to sulfate attack on cementitious grout systems. For the project in Spain presented in my paper, we used a very high pulverized fuel ash (PFA) content in the cementitious material. This gives good sulfate resistance and indeed the chemical interaction will actually cause the permeability to drop for about 50 years without any question of sulfate attack and damage to the whole thickness of the grout - of course there will be attack at the exposed face of the grout where it is in contact with the contaminated groundwater. The mix had over 75% PFA, and also a very high overall cementitious content. The mix was the contractor's design and showed excellent behavior in laboratory proving trials. In grouts as distinct from concrete, PFA gives significantly better sulfate resistance than ground granulated blast furnace slag which is often used in Europe as a component of bentonite-cement mixes for slurry trench cut-off walls.

Feb 10, 2003

By Raymond Henn

Yes we have also used some however, again because of the nature of the maintenance window where we have that two hour (at best) window every night and due to the numerous other crews that are wanting to get in to do the other types of maintenance activities, we don't know if we are going to be getting into that same area from one night to the next. So even with the dormancy additives that one can add to cementitious grouts (that are good up to 72 hours) we don't know if we are going to get back in to the same locations from one week to the next. That's why I use the term "the forgiving nature of the acrylamide". It allows us to ream out the hole allowing us to use the exact same hole without having to re-drill a new hole. The program started in 1997 and we have a budget between labor/materials and equipment of 4.5 million dollars on a year to year basis. For the next few years that is going to come down drastically because the program is going to be more of an ongoing maintenance program. The program started in 1997 and we have a budget between labor/materials and equipment of 4.5 million dollars on a year to year basis. For the next few years that is going to come down drastically because the program is going to be more of an ongoing maintenance program. Up to the end of 2001 we were just over 1.7 million liters of between AV100 and AV118 grout. Of that, approximately just under 200,000 was AV100 and the remaining balance was AV118.

Feb 10, 2003

By Richard Berry

The spacing of grout injections is typically about 2 to 2 V½ meters if the purpose of the grouting is densification of the in-situ soils. Hole spacing will vary with the in-situ soil properties and the grout injection rate; faster rates requiring closer hole spacing.

Feb 10, 2003

By Stephan Jefferis

It is my understanding that the Scandinavians have done some fundamental work on durability. I have seen a study published whereby the author, Helen Anderson, comments on the durability of polyurethane grouts and there was -if I am not mistaken- a reference made to another Scandinavian testing institute comparing durability of the polyurethane to cement grout under the same type of circumstances. Circumstances are important so we should actually ask the gentleman to shed some light on this particular method because apparently Scandinavia is the place where durability has been taken very seriously and has been well researched.

Feb 10, 2003

By Trent Dreese

For critical velocities in gravel units we use Bush-Luckner, Sichardt, other empirical equations, and equations derived from laboratory experiments too. On the base of these, we compiled critical velocity - permeability coefficient dependencies. Under the lower border of these dependencies sand particles can't be moved, and thus they are stable. For critical velocities in the fissures of flysh and volcanic rocks we use Ronzhin (1974) criteria derived from laboratory experiments in Russia. Maximal filtration velocities measured by tracer methods in gravel soils and in fissured rocks have smaller values then the critical ones.

Feb 10, 2003