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By Al Holmes

"In a recent survey of Canadian work values, 89% of the men surveyed and 97% of the women surveyed described the work in a mine as ""not at all auraetive"", Work in a mine, in fact, was rated by both sexes as the least attractive of all of the types of work surveyed. Confronted with this prevailing attitude, Canada's mining industry starts out with two strikes against it in its bid to attract and hold on to its fair share of available work force.Behavioural scientists have, for decades, been seeking answers to the questions:• ""Why do people work?""• ""Why do people choose a particular occupation?""• ""Why do people choose a particular organization?""• ""Why do people leave one organization for another?""• ""Why do some people stay in an organization?""• ""Why do some people work harder than others?""Their answers to these questions, although tentative and often contradictory, are being used by more and more organizations to solve people problems. Few industries can afford to ignore them, least of all, perhaps, the mining industry.Consider the following developments:I. General Motors and the United Auto Workers turn around the car assembly plant in Tarrytown, New York in seven years from the plant with the poorest labour relations and production record to one of the best under a program referred to as ""improving the quality of work life.""2. Shell Canada and the Oil, Chemical and Atomic Workers have designed a new petro-chemical processing plant in Sarnia using a set of principles that seek to optimize both the social and the technical system."

Jan 1, 1980

By A. Sargeant

This paper evaluates the application of post consumer glass as a cementing agent in underground mine backfills. The underlying theory indicates that glass is pozzolanic and, when used in a finely divided form, behaves as an activator to generate binding products, thus contributing to the development of backfill strength. The objective of this study was to evaluate the strength performance of backfills when Normal Portland Cement is replaced with various percentages of post consumer glass. The study evaluated the performance of backfills prepared using tailings from three mines. Each backfill was prepared using unique recipes, and were evaluated at cure times of 7, 14, 28, 56, 112 and 224 days. Laboratory work involved visual, physical and chemical material characterization followed by strength evaluations. Results of strength assessment revealed that backfill prepared with glass is reactive and can contribute to the strength of backfill. The results also indicated that the reactivity of glass may be affected by the incorporation of slag within the recipe, the availability of lime and the level of hydration of the binders. The study concluded that, at 15 % glass replacement of NPC, backfill prepared with mine tailings, NPC and glass can achieve improved or equivalent strength performance compared to backfill prepared tailings and NPC alone.

May 1, 2007

By J. Walenzyk

This report investigates the limited use of super large backhoes in surface mines around the world. The demand for super large (> 700 t) hydraulic excavators is rising and most of the machines are sold as front shovel (FS) application. Despite advantages in faster cycle times super large backhoe (BH) machines are a minority (ca. 1% of the total machine population). This investigation is based upon the comparison between the volumes available to the BH and FS in one block and before the machine needs to move. The working conditions are created with standard parameters as given by Original Equipment Manufacturers of hydraulic excavators regarding bench height, angle, and material density. The travel amount of both machine types is derived from these volumes and compared. Furthermore, the travel amount of super large BHs is compared to the travel amount of smaller mining BHs and evaluated based on attachment length and bucket size. The calculations conclude that the volume of material recoverable in a single spot is about 75% higher for FSs. This leads to an increased travel for BHs. The combination of both the increased appearance of electrical driven machines (in the class of > 700 t excavators) and the travel amount lead to a high risk of damaging the cable or the excavator. Enlarged wear on the travelling parts is also attended by the higher travelling. A direct comparison of commonly found working set ups shows that the ratio between volumes is 32% which leads to an increased travel amount. In comparison with a 250 t BH, the calculation shows that the smaller BH is able to reach nearly 50% of the volume of the super large BHs. The main reason for this is the respectively high reach on smaller machines which, combined with other factors, leads to a significantly higher number of BHs in lighter classes.

Aug 1, 2013

By M. J. Brodie

"The decision to proceed with mine decommissioning, generally involves a number of complex and independent factors. These factors, including potential for re-opening, legal requirements, contingent liability, asset depreciation, due diligence, and public relations are discussed in the context of the financial implications on a net-present- value basis. It is concluded that the decision to delay mine decommissioning is commonly not in the best financial interests of the mine operator. Some measures to reduce decommissioning costs and expedite the process are presented.IntroductionThe primary audience for this paper is mining executives, although it should be of interest to all professionals involved in the planning and carrying out of mine decommissioning. Historically, mines were abandoned, not decommissioned. Then, as decommissioning became required, it was assumed that salvage revenue would pay for decommissioning. During the I980s, it became apparent that mine decommissioning costs would exceed salvage revenue for nearly all sites, and that a substantial net cost for decommissioning would be realized for some sites. Throughout this period, the approach to decommissioning has evolved through the sequential addition of measures to meet the increasing regulatory burden. This has resulted in a process in which the elements of decommissioning may not be optimized with respect to each other for the most favourable net present value to the corporation. Additional considerations which are not specific to mine decommissioning, such as environmental policy, due diligence and public relations, may now come to bear on the decision-making process.This paper addresses the issue of mine decommissioning as a three-step process. The first step involves identification and evaluation of all of the issues that relate to mine closure, the most importantof which is the potential for re-opening of a mine. Assuming that it is decided that a mine is unlikely to re-open, the second step is to determine when to carry out the decommissioning work. This aspect is examined through a net present value (NPV) approach. Finally, details regarding who does the work and how the various tasks are divided up must be resolved.Every mine is a unique concentration of minerals at some specific location, hence the development, operation and closure of a given mine must be regarded as a special case. Superimposed on the site-specific considerations are the size, history and financial status of the associated corporation."

Jan 1, 1995

By J. Karonen, M. Tiihonen, J. Guentner, L. Haavanlammi, Outotec GmbH, E. Kolehmainen

"Rare earth elements have obtained significant attention during the last few years due to predicted increase in their demand. Several projects worldwide are at pre-feasibility or feasibility stage aiming to commence production. Deposits of rare earth elements are typically complex and multi-metallic of nature. This means that production processes are often also complex and therefore, various metallurgical unit processes are needed. Outotec’s equipment and technology portfolio is very comprehensive and includes hydrometallurgical and pyrometallurgical apparatus and processes applicable to the efficient exploitation of rare earth deposits. Outotec has gained useful experience relevant to the processing of rare earths through several assignments including those for Alkane Resources Ltd. (Dubbo Zirconia Project), Greenland Minerals and Energy Ltd (Kvanefjeld Project), Frontier Rare Earths Limited (Zandkopsdrift project), Tantalus Rare Earths AG (Madagascar), Quest Rare Metals (Strange Lake project) and Orbite Aluminae Inc. (HPA project). The hydrometallurgical test work of two process flowsheets is presented in the paper. A roasting or acid baking step is common to several proposed rare earth projects. In the past, rotary kilns have been used, but Outotec has developed a new process concept to handle the rare earth material in fluid bed reactors. The basis for this development is long experience in fluid bed technology of Outotec in Germany. One advantage of fluid bed roasting is the higher throughput per unit. In combination with the roasting and baking, Outotec offers the gas cleaning and acid plant and provides a complete and closed concept.INTRODUCTIONRecovery of rare earth elements (REE) has obtained significant attention during recent years. It has been estimated that their demand will be boosted because of their need in many technology areas. REE can be utilized in magnets, batteries, displays, catalysts, optical devices etc. (Jordens, Cheng, & Waters, 2013; Zhang & Edwards, 2013). The production of REE is focused in China, which means that production outside of China is very scarce. However, there are multiple active development projects worldwide working towards production of REE containing products outside of China (Chen, 2011)."

Jan 1, 2016

By Gordon Thompson

"Development of the unique Mine Games exhibition at Science World British Columbia is the largest ever collaboration of many interests to present the story of mining and the issues of mineral development delivered to the public by a science education centre.IntroductionMineral education programs have long been a major focus of the British Columbia mining community. Mine Games and its tremendous potential to enhance industries image and the public's awareness of mining is unequalled in the field of Issue Based Education Exhibits.The main goal of the exhibition is to look at the future of resource industries in a rapidly changing world of economic activities, new technologies, and growing public concern for the environment. Three challenges were the aim of the exhibition: to increase participation, to serve as a tool to increase interest in science and technology, and to draw an increasing number of school students to the interests of geology and the earth sciences. Mine Games is to serve as a meeting place for discussion of issues and where reliable information can be shared and new ideas explored.The exhibition is designed to develop new approaches to hands on learning that encourages visitors to explore and generate discussion and thinking with respect to resource development activities.The role of author, beginning in 1993, was, with senior industry leaders, to coordinate the raising of $1.3 million to complete the funding of the $1.6 million project total. The second and most interesting challenge was to work with the many minds that were collaborating to create the exhibition and to assure that the facts and science were correct. This involved the coordination of ""expert groups"" that verified the science and technology and the issues that the creative design team at Science World planned to use in development of each exhibit module."

Jan 1, 1995

By Patrick R. Taylor, T. A. R. Putra

A review of various methods to treat high arsenic copper concentrates through pyrometallurgical processing is presented. Examples are drawn from various past and current operations and research. Various aspects of the engineering alternatives for treatment methods are discussed. Some of the methods discussed include: controlled oxidation roasting, adaptation of some smelter technology to accept higher amounts of arsenic, complete oxidation with arsenic fixation; sulfation roasting; acid baking, soda ash roasting, and others methods. Other topics include: a short discussion of other problematic impurities; the effects of arsenic on copper electro-refining and product purity; and methods for the ultimate disposal, or marketing, of the arsenic. The latest work being done at the Colorado School of Mines on soda ash roasting is also presented.

Jan 1, 2014

By S. Zakaria

"Inco's Automated Haulage Truck System (AHT) is a revolutionary automatic guided vehicle that performs all load, haul and dump operations without human intervention. The high level of sophistication and the short period it has been in operation has only allowed a select few Inco personnel to become familiar with the ART operation and maintenance. As an aid to operations an expert system using the knowledge gained from the experienced specialists was implemented in the field.The AHT operating and maintenance assistance expert system will reason through the information given, arrive at conclusions and give advice to operations, technical and management personnel. It will provide comprehensive real-time troubleshooting assistance for the hydraulic, electrical and mechanical subsystems of the ART. The ART expert system has many benefits to Inco which include increased skill levels of ART operations and maintenance personnel, reduction in ART downtime, standardization of troubleshooting procedures and reduction in ART operating and maintenance costs. In the future, the expert system application will be linked to SCADA (Supervisory Control and Data Acquisition), maintenance and statistical software to display current and historical trends of variables from a centralized historical database. As well, a wide variety of features will be integrated into the system including AutoCad drawings, graphics, photographs, voice and video capabilities."

Jan 1, 1994

By Lawrence Devon Smith

"The concept of risk is well established in the mining industry. It is acknowledged when estimates of reserves are expressed as proven or probable, when mining and metallurgical recoveries are applied to the ore, and when contingencies are added to costs. However, it is difficult to provide a quantitative assessment of risk. The significant sources of risk in a mineral project and how these are addressed in project evaluations are discussed.The discount rate is examined as a fundamental means of reflecting risk in discounted cash flow evaluations. Current industry practice is discussed, and a methodology for the analysis of risk levels is proposed that assesses the constituent components of the discount rate: real interest, mineral project risks, and country risk.IntroductionThis paper examines the components of the discounted cash flow discount rate and proposes a method of estimating project-specific discount rates. The motivation for this work comes from experience of project evaluations in which owners and purchasers had agreed on virtually every aspect of the evaluation except how much the project was worth. Agreement was reached on reserves, grade, recovery, capital costs, operating costs, taxes, and, by combining these components, even on the final cash flow values. The only difference in opinion concerned the discount rate to be used in the calculation of the net present value. Depending on the life of the project, such differences of opinion can cause a variation of more than 50% in the value placed on a project! This is illustrated in Figure I."

Jan 1, 1995

By C. O. Aksoy, P. M. Ozfirat, M. K. Ozfirat, C. Tatar, C. Pamukcu

"Temporal and other factors contributing to the occurrence of occupational accidents at an underground coal mine in Turkey between 1992 and 2000 have been analyzed. The time period of the study spanned the transition from hand-worked mining methods (1992 to 1996) to hand-worked mining methods and mechanized mining methods (1997 to 2000).The mine selected for the study employed an average of 5,835 men per year on three separate eight-hour production shifts for 302 d/y (Sundays are not worked, and there are 11 holiday days per year). Production on an annual basis averaged 190,000 tons per year between 1992 and 1996, and 300,000 tons per year between 1997 and 2000.The purpose of the study was to determine which, if any, of the factors studied contributed to the occurrence of accidents so that the mine could take the necessary steps to reduce the risk to the workforce. Regression analysis was used to determine the strength of the relationship between each factor studied and the number of occupational accidents.The strongest relationships observed were between the age of the employee, the day of the week, and the total yearly labour."

Jan 1, 2006

By Jane Li, Kevin Tom

"Research has shown that broken rock on conveyor transport systems can contribute upwards of 50% towards the overall heat load in underground mines. However, few studies have made significant efforts to predict the temperature distribution of the ore and air simultaneously, which can help implement heat management strategies. The present investigation explores a transient, analytical heat transfer model to track ore-pile temperature distributions, along conveyor systems in an example underground mine. Production rate, ambient conditions, ore pile thickness and belt velocity are adjusted to evaluate the effect on dry and wet bulb temperatures.INTRODUCTIONWith an ever increasing demand on Earth’s resources due to a multitude of factors like population growth and step changes in technology, pressure on the mining industry to bring out more ore with improved margins is a persistent challenge. Typically, high-volume producing mining methods (i.e., exceeding 5000 tons per day (tpd)) such as sublevel and block caving, room and pillar, and longwall shall utilize belt conveyors instead of trucks as the primary haulage method to surface to save on operational costs (de la Vergne, 2014). However, studies have shown that when such material transport systems are installed at mine depths with virgin rock temperatures (VRT) above 40oC, the heat dissipated by the conveyed ore can account for over 50% of the underground heat-load (Pareja, 2000; Bluhm, Jones, Moreby, & von Glehn, 2012; van den Berg, Moreby, & Kok, 2015).Unlike other types of heat sources encountered in underground mines, such as diesel machines, strata, electrical devices, and autocompression, heat transfer by conveyed broken rock is much more difficult to estimate. The seminal work of McPherson (1993) states that broken rock heat transfer is a function of its surface area, and the air’s psychrometric condition. It is additionally a function of the VRT, its specific heat, production rate, heat transfer coefficient and the residence time (Bossard, 1997; Ross, Tuck, Stokes, & Lowndes, 1997). Consequently, few studies have attempted to analytically quantify the significance of ore heat flow."

Jan 1, 2019

By H. E. Wilde

"Zinc has been used for many years as a galvanic coating for the protection of steel. Electrochemical measurements show that zinc actually overprotects steel. The corrosion rate of DQSK (drawing quality semi-killed) steel in air saturated salt water was determined as a Junction of applied cathodic potential. The resulting data indicate that at a critical cathodic over potential of - O. 725 Vsce an acceptably low corrosion rate of less than 1 mpy occurs. Using the developed criterion, alloys of Zn/X and AL/X were produced and evaluated in galvanic contact with steel in a standard laboratory test. The results indicate that Zn /Mn, Zn /Co, AI/Mg/Si and AI/Mg/Ge alloys offer excellent galvanic protection along with (a) no hydrogen evolution, and (b) improved dissolution life over Zn coatings.IntroductionZinc coated (galvanized) steel has been successfully used in applications where bare (or painted non-galvanized) steel would suffer corrosive attack. In general, galvanic coupling to zinc, as either an anode or a coating, is an effective means for combatting steel corrosion. Because of this, the use of galvanized steel has increased markedly, stimulated primarily by automobile manufacurers seeking to extend the corrosion warranties on automobiles(1).Although effective, zinc coatings are not without a number of drawbacks which warrant efforts to improve them. For example, because of the widely differing electrode potentials between zinc and steel ( - 1.05 Vsce and - 0.60 Vscc, respectively, in air saturated NaCl solutions), the zinc corrodes at a rapid rate to protect the steel. This is reflected in the limited lifetimes of galvanized unpainted siding. The basic electrochemistry controlling the situation is shown in Figure 1, for a system controlled by oxygen reduction. The zinc corrodes sacrificially to protect the steel, while cathodically polarizing the steel to a potential near that of zinc's open circuit anode potential."

Jan 1, 1990

By Naizhong Xu

During the past 30 years, fully mechanized caving mining has played a positive role in the improvement of the efficiency of coal production, but which has also had a great influence on the mining environment, especially to environment damage of shallow mining areas in the central and western regions of China. The surface subsidence parameters are the basis of the surface environment evaluation and governance. During 1980~1990s of the last century in China, fully mechanized mining subsidence laws were researched more fully, however, since coal caving technology is affected by many factors, and researches on its mining subsidence laws (parameters) were found to be grossly inadequate. Through actually observed in recent years, it is considered that coal caving mining subsidence laws (parameters) can use fully mechanized mining law (parameters) for reference. Based on fully mechanized mining laws (parameters), this paper reveals the similarities and differences of the surface subsidence laws between fully mechanized caving mining and fully mechanized coal mining, which can guide the work of coal mining under buildings, water bodies and railways in new mine area and mine collapse governance.

Aug 1, 2013

By G. Mihaylov

The basic principles of systems analysis are presented. A model has been designed to determine the location of the Main opening in the presence of three or more stock orebodies. The necessary condition is to find a location for the Collection point which is an essential element in opening up each orebody (stock). The model takes into account the total transportation costs from each orebody to the collection point. Three variants are considered provided that the orefield is divided into two levels at least: - a collection point is designed at every level; - a collection point is designed at the lowest level, i.e. where the so-called concentration level is formed; - the collection point is located at a point between the planes of the two levels; The effect of the depth of mining and mine output on determining the method of opening up the orefield has been analyzed by considering a vertical and/or an inclined shaft. A function has been constructed which allows for investigating in both a static and dynamic regime the capital costs for constructing the whole complex including the shaft. The character of the function does not allow finding the global limits. Therefore, it is of particular importance to specify the limiting conditions. In this case these are the flow capacity of development openings and the shaft. The basic groups of cost and natural indicators for assessing and selecting an optimal technological solution have been systematized. The combined analysis of the two approaches to finding the location of the Main opening and determining the mining method enables us to determine when an inclined shaft is best, and the depth at which opening by a vertical shaft has no alternative. Thus, a transition area is formed for which the selection of an optimal technological solution requires an analysis similar to that proposed in this paper. Conclusions are finally drawn which serve as a basis for determining the areas of application of each opening, including the use of a combined scheme of mine opening. The approach presented can be used in both investigating the possibilities for opening up new orefields and reconstructing existing ones in cases when the mining operations go deeper.

Aug 1, 2013

By J. Ambrose, R. W. Zimmerman

"Shales are highly anisotropic in their mechanical behavior. The strength ( ??1) of anisotropic shales depends not only on the magnitude of the other two principal stresses ( ??2, ??3), but also on the bedding plane orientations (?) relative to the principal stresses. In this study, the role of the intermediate stress ( ??2) on the strength of shale is evaluated using new data from triaxial compression and extension tests. To understand the failure behavior of shales, we have carried out triaxial compression tests ( ??1 > ??2 = ??3) on two organic rich mudstones, at different confining stresses and loading angles. We first fit the triaxial compression data with Jaeger’s plane-of-weakness model, and find that the model is able to represent the strength behavior of anisotropic shales reasonably well. We then carried out five triaxial extension tests ( ??1 = ??2 > ??3) for a high strength-anisotropy shale, and two extension tests for a low strength-anisotropy shale. Results from the compression and extension tests for failure along the weak plane shows that the role of ??2 is not significant for weak plane failure. However, for the low strength-anisotropy shale, the failure strength of the intact rock (i.e., at ??= 0o and 90o) for compression and extension tests were significantly different. This indicates that for intact rock failure, the role of ??2 is important and cannot be ignored.INTRODUCTIONFor many years, various researchers have studied the roles of ??2 for failure of isotropic rocks. (Mogi, 1967 and 2007; Colmenares and Zoback, 2002; Al-Ajmi and Zimmerman, 2005 and 2006; Haimson, 2009; Ma and Haimson, 2012). The findings from these studies show that the effect of ??2 on the strength of isotropic rocks is generally significant, and cannot be ignored.Since the role of ??2 in the failure of isotropic rocks was recognized, other researchers attempted to extend some of these isotropic failure criteria to anisotropic rocks, but with limited success (e.g., Tiwari & Rao, 2007; Singh et al., 1998; Zhang and Zhu, 2007; Pei, 2008). Smith and Cheatham (1980), on the other hand, conducted true-triaxial experiments on the Green River Shale and used a J2-I1 type relationship to predict the strength behavior, but without considering the effect of the three-dimensional orientation of the weak plane on strength. Therefore, unlike for the case of isotropic rocks, additional studies need to be done to determine the role of 2 on the failure of anisotropic rocks."

Jan 1, 2015

By Robert B. Parsons

"Income tax legislation is not keeping pace with federal and provincial environmental legislation. There is a vast array of new environmental regulations at various stages of implementation across the country. Unfortunately, there are serious concerns about the deductibility of significant payments which mining companies will be required to make under these new rules, and the Department of Finance seems to be reluctant to act on these concerns. IntroductionWhile the federal and provincial governments are racing ahead with obvious fervour to introduce new envirorunental laws, the tax rules relating to envirorunental costs are being allowed to lag far behind. In a nutshell, the tax treatment of envirorunental costs is not keeping pace with the new envirorunental legislation.One of the most serious concerns of the mining industry is the deductibility of mine reclamation or closing costs. The producing provinces are well advanced down the road toward mandating upfront deposits, bonds, or similar financial guarantees to protect the envirorunent from the operation and eventual closure of a mine. These requirements are not small. In some instances, they can amount to tens of millions of dollars. And, if there is no tax deduction for these sums when they are set aside by the mining company, then the costs have to be paid out of the company's after-tax earnings."

Jan 1, 1991

By Sazol Das, Hany Ahmed, Ganesh Bhaskaran, Zhuoru Wu

"Friction stir welding (FSW) process in lap configuration for dissimilar materials has been developed and tested for steel to aluminum joining. A novel cylindrical tool was designed for improved material flow. The joining of steel to high strength 5xxx and 6xxx aluminum was carried out by FSW technique using optimized process parameters. The microstructure, micro-hardness, joint strength and corrosion properties at the weld interface have been investigated. Optical and scanning electron microscopy reveled a well layered structure at the interface and lap shear tests of the welds showed excellent fracture resistance. Neutral salt spray tests for up to 500 hours (ASTM B117) were carried out on the bare steel to aluminum FSW joints, which did not show neither evidence of corrosion at the weld interface, nor any degradation of the weld strength. The FSW lap configuration was applied to prototype commercial vehicle structural component whereby a steel stiffener insert was friction stir welded to high strength 6xxx aluminum alloy. The interface microstructure showed layered root without any steel shattering in aluminum side. A finite element study was carried out to quantify the benefits where it was found that the stiffness increases by 76% under bending loads and 36% in torsion loads.INTRODUCTION Energy preservation and environmental issues, namely carbon footprint and legislation around emission in transportation industries has led to a growing need to use of lightweight materials such as aluminum and magnesium alloys along with various grades of steel in structural application, while still maintaining their strength and crashworthiness. Assembling dissimilar materials within integrated structure is thus a stringent requirement related to optimum performance. In order to achieve an efficient technology of joining dissimilar materials such as aluminum to steel, it remains difficult to select an effective welding process for a given joint configuration. The use of aluminum in transportation industries for structural component is not exclusive in a design and is almost always used along with various steel grades for a mixed materials solution, thus dissimilar aluminum/steel lap joining is of great interest since this is widely used in the assembly of parts (e.g. pillar, frame rails, chassis, body in white (BIW), CAB, etc.)."

Jan 1, 2018

"AbstractThe Sedimentary Basin area of Western Canada, which lies between the Precambrian Shield and the Cordilleran mountain area, covers approximately 800,000 square miles. Sediments ranging in age from Cambrian to Tertiary are present and, of these, horizons in the Upper and Lower Cretaceous, Jurassic, Mississippian, and Devonian have yielded commercial oil and gas flows. Producing horizons in the Cretaceous and Jurassic are sandstone, while all those of the Palaeozoic are carbonate rocks such as red limestone or dolomite (bioherms). Shows of oil and gas have been encountered also in the Cambrian and Triassic sediments.The broad structural features of this vast expanse of sedimentary rocks are the Moose Jaw syncline, the Sweet Grass-Battle River arch, the Alberta syncline, the Foothills belt, the Rocky and Mackenzie mountains, the Great Bear-Slave Lake basin, and the Mackenzie Delta Basin area.This contribution outlines the .stratigraphy and structure of the Basin area, and gives examples of present producing oilfield structures and stratigraphic traps.Part 1.-Regional StratigraphyIntroductionThe vast expanse of relatively undisturbed sedimentary rocks of western Canada has long been recognized as prospective territory to search for oil and/ or gas. This search in western Canada dates back before the turn of the century, but, considering the size of area to be explored and tested, the effort an<l money expended upon it, which, before the recent discovery of oil at Leduc, Alberta, appeared large and fruitless, now seems almost ridiculously small. A check-up of effort and money expended prior to and since the Leduc discovery would undoubtedly reveal that more wildcatting and development has taken place during the last two and a half years than during all previous years combined. The figures would astound not only the average citizen, but many within the industry itself."

Jan 1, 1950

By Zorigtkhuu Davaanyam, Fisher Wang, Bern Klein, Amit Kumar

"The High Pressure Grinding Roll (HPGR) is an increasingly popular energy efficient solution for comminution of competent ore deposits that primarily competes with conventional crushers and tumbling mills. A significant barrier to increased adoption of HPGRs is the requirement for large amounts (one tonne or more) of sample for pilot testing which may not be feasible for most early staged projects.Various researchers have worked towards developing piston-die and JK drop weight tests to model and predict the energy requirements for an HPGR. Two small scale laboratory test procedures (the SMC test (Morrell, 2009) and the piston press tests (Davaanyam, 2015)) have been developed in recent years to provide necessary information to size an HPGR.These two methods were used to estimate the required specific energy for an HPGR unit and compared to HPGR pilot scale test results from a copper deposit. The comparison provides insight into the benefits and limitations of these tests.INTRODUCTIONHigh pressure grinding rolls (HPGR) have gained popularity in recent years because of their energy efficiency in comminution. Various researchers have suggested that approximately 50–80% of the total energy consumed in a mineral processing plant is used by the comminution equipment (Haque, 1999; Abouzeid & Fuerstenau, 2009; Wang, 2013). Haque (1999) showed that the efficiency of grinding equipment can be as low as 1%. Due to the energy intensive nature of comminution, mining industry has been forced to explore alternative energy efficient processes.An HPGR based circuit has been shown to be 10–25% more energy efficient than a conventional SABC circuit (Von Michaelis, 2009; Wang, 2013). A significant barrier to the increased adaptation of HPGRs is the requirement for a large amount of sample for pilot testing (up to 5 tons), even on a prefeasibility level. Numerous studies have been performed to utilize piston press test to analyze the performance of the HPGR circuit and to predict the energy consumption for an industrial application. This paper uses two small scale laboratory test procedures, the SMC test and a piston press test, to compare the energy requirement to the pilot HPGR data."

Jan 1, 2016

By Simon Houlding

"The objective of Part J of this paper is to identify the limitations of the traditional modelling methods and to illustrate, by example, the potential for error created by their application to complex deposits and mining situations. Part 2 describes the evolution of new, proven technology which eliminates these deficiencies and provides precise and practical alternatives. These promote the use of realistic geological and mining shapes and eliminate altogether the rectangular approximations of traditional methods.The Case for Precision ModellingIt is not the intent of this paper to promote the benefits of computer modelling per se. It is assumed that these are recognized by the mining industry in general. The concern of Part 1 is to identify, qualify and quantify (where possible) the limitations of the tractitional modelling methods. In many instances these methods continue to be applied to complex geological and mining situations for which they were never intended nor designed. The source and magnitude of the resulting errors, conflicts and inefficiencies are not always obvious, however, they can have far-reaching effects on the efficiency and profitability of mining operations.The conclusions support a rapidly growing demand by industry for practical, precise modelling technology which eliminates the deficiencies and can be applied with confidence to evaluation, design, planning and control of mine production in all situations. Part 2 describes new technology which has evolved in response to these industry pressures and has already been successfully applied to complex mining situations. This new technology can aptly be described as appropriate technology for the 1990s."

Jan 1, 1991