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"11.1. IntroductionThe recovery of platinum-group elements (POE) from ores is a subject which has received almost no mention in the literature. Edwards (1975) refers to the process used for refining of the POE, throughout the Western World, as a so-called ""conventional"" process .... ""not because of the simplicity or convenience of the operations, but more probably because of the inertia of established processes and the aura of secrecy with which the major platinum refiners have surrounded this process."" There is no doubt in this writer's mind that the latter is also applicable to the dearth of knowledge of the mineralogy, geochemistry and ore deposits of PGE and that the poor recoveries, mainly attributed to the mineral beneficiation stages of concentration, are also affected by this traditional secrecy. Fortunately, this attitude is changing, due no doubt to the advantages that accrue from more open research which may be critically assessed in the literature in the traditional manner. Examples of this more open approach to recoveries and recovery problems are represented by Newman (1973), who gave some typical recovery percentages for Merensky Reef ores, and the recent encouragement and cooperation on mill samples from the Sudbury area by lnco Metals Company (cf. Cabri, 1981a).In general, platinum-group elements are recovered from an ore by the use of a physical concentration method, such as gravity separation or flotation, followed by further upgrading using further physical, wet chemical or pyrometallurgical techniques. The final process of refining in which the individual platinum-group elements are produced in pure form is outside the scope of this chapter.Platinum-group element deposits naturally fall into different categories according to the recovery process best suited for them, viz. those amenable to gravity separation, those amenable to flotation, and those where platinum-group elements are by-products of base metal sulphide, chromite and miscellaneous other deposits."

Jan 1, 1979

By Frank Ebbutt

Introduction The property of the Britannia Mining and Smelting Company, Limited, is situated on the east side of Howe sound, about six miles from its head. It is roughly thirty miles by water from Vancouver, one of the important ports of the Pacific and the industrial and financial centre of British Columbia. Howe sound is navigable for ocean-going vessels and Britannia Beach is a daily port of call for the commodious boats of the Union Steam-ship Company, sailing from Vancouver. Few mines are so ideally situated or have so many or varied natural advantages. Copper was first found on Britannia mountain in 1888, by Forbes, but it was not until 1898 that five claims were staked here by Oliver Furry, a trapper. It is from these claims that the major production during the past thirty years has come. In 1900 the Britannia Copper Syndicate was formed and development of the property was commenced. In 1903 the late Grant B. Schley obtained control, and through his efforts the Britannia Mining and Smelting Company was organized in 1908 as a subsidiary of the Howe Sound Company. Since that time, a persistent and progressive policy has been followed, which has resulted in a prolonged and profitable operation. The country in the immediate vicinity of the mine is marked by strong relief, with mountains rising abruptly from tide-water to elevations of 5,000 feet and more. Two broad transverse valleys deeply dissect the area. These are the valleys of Britannia creek and Furry creek. The region has under-gone prolonged and relatively recent glaciation. Over much of the surface there is deep overburden and dense vegetation. The geology of the mine and vicinity has been described in reports by S. J. Schofield (1), H. T. James (2), J. G. Barry, and others (3). The present writer is in accord with much of this literature on Britannia, but during recent years, extended observations made underground have shown that the 'quartz porphyry', or 'mine porphyry', of several of the earlier writers is not the host rock to the commercial mineralization; and he contends that the mineralization occurs in highly altered phases of a complex series of ruffs, flows, and pyroclastics and their autoclastic metamorphosed products.

Jan 1, 1935

By D. F. Sangster, P. J. Hood, G. A. Gross

"Some results are presented of an integrated geological and geophysical study of Precambrian magnetite-quartz iron-formation in the Kapiko Iron Range north of Nakina, Ontario. Detailed geological and topographical mapping was carried out in conjunction with detailed geophysical investigations such as vertical magnetic field, vertical magnetic gradient, hammer seismic, horizontal-loop electromagnetic and magnetic susceptibility surveys. In addition, oriented drill cores were obtained for magnetic polarization studies.Vertical-force magnetic anomalies within individual rock units showed a strong positive correlation with topographic relief. Moreover, magnetic intensity was found not to be quantitatively proportional to the magnetite content in the rocks, due to the presence of high remanent magnetization of the magnetite. Also, the remanent polarization direction was sub parallel to the plunge of the fold structure and mineral lineation in associated rocks.Vertical magnetic gradient measurements were found to be more accurate in locating buried contacts between magnetite-quartz iron-formation and country rock than the vertical magnetic force data.An in-situ magnetic susceptibility meter was used to measure the magnetite content of iron-formation, and the measurements were subsequently compared with vertical-force magnetic results.The results of the EM survey were inconclusive; some magnetite-rich zones produced anomalies in the out-of-phase component. whereas others did not. The reasons for such inconsistencies are not yet apparent.Longitudinal seismic wave velocities measured parallel to the bedding in magnetite-quartz iron-formation ranged from 10,600 ft/sec. to 14,500 ft/sec. The seismic velocity appears to increase with an increase in deformation of the rocks."

Jan 1, 1966

By Amauri Garcia, Rodrigo Valenzuela Reyes, Noé Cheung, José Eduardo Spinelli, Leonardo Fernandes Gomes, Rafael Kakitani

"The present research work deals with directional solidification (DS) of both Al-15wt.%Si and Al-15wt.%Si-1.5wt.%Mg alloys and further characterization of the related microstructures. The growth of refined primary Si and refined eutectic is well-known as positive in order to improve mechanical properties of the Al-Si based alloys. Alloying is also an effective method to strengthen the Al-Si based alloys, in which Mg is considered an important alloying element. However, lack of investigation regarding the effects of Mg on microstructure of these alloys is noted. So, in the present research work emphasis is given on both dendritic and eutectic growth being affected by solidification kinetics (V-growth rate and G-thermal gradient) during transient directional solidification. Experimental evolutions of microstructural spacing of both alloys have been determined which becomes possible to understand the effects of Mg coupled with the effects of growth rate on the final microstructural arrangements. A direct comparison of the tensile mechanical properties obtained for the alloys is also performed. It is shown by these correlations that the addition of Mg generally improves the tensile mechanical resistance with a minor decrease in ductility. Furthermore, the Scheil solidification path of the ternary Al-Si-Mg alloy was determined using the computational thermodynamics software Thermo-Calc, resulting in the following sequence of precipitation: Liquid-Si-a (Al)+Si- a(Al)+Si+Mg2Si. This sequence is compared with the experimental microstructure findings.INTRODUCTION Al-Si alloys containing from 4wt.% to 22wt.% Si comprise more than 90% of all Al-based castings. Parts manufactured with these alloys have a wide range of industrial applications due to their excellent castability, crack resistance, good corrosion resistance, good weldability, low density and high strength (Bray, 1976; Zolotorevsky, 2007; Reyes, 2017). Hypereutectic Al-Si alloys are widely used and researched in the automotive and aerospace sectors due to the low coefficient of thermal expansion, resistance at high temperatures, good wear resistance and high strength (Reyes, 2017; Tebib, 2013). Above the equilibrium eutectic composition (~12.5wt.%Si) the amount of primary Si particles becomes significant (Lasa, 2003). In the place of conventional hypoeutectic Al–Si, there is growing interest in hypereutectic Al–Si alloys as a candidate material for the high-quality engines because a higher volume fraction of silicon may bring about superior properties (Matsuura, 2003)"

Jan 1, 2017

By J. P. Weiler

The increasing use of high-pressure die-cast magnesium alloys in the automobile industry requires a better understanding of the mechanical properties, the microstructure, and particularly, the relationship between these two. The goal of this study is to first understand the microstructural features which control the mechanical properties observed from an AM6OB magnesium alloy, and second, to be able to predict the local mechanical properties based on microstructural features encountered in different areas of the die-cast component. The two main tools used in this study are spherical indentation testing, used on local areas of the die-cast magnesium alloy AM6OB to detect changes in microstructure and mechanical properties, and X-ray tomography, used to non-destructively investigate the internal porosity in a sample. The results from these tests are then used to predict the local mechanical properties such as the yield stress, the strain-hardening characteristics, and the fracture properties of the AM6OB component.

Jan 1, 2006

By Frank Ebbutt

In this paper it is proposed to point out certain structural factors that; have an important bearing on gold deposition. The subject will be treated; more or less generally. Although the writer has had access to a great many; of Canada's gold mines he does not wish to take the liberty of discussing; details of any particular mine or mines; the aim will be to discuss controls; that are evident in many places.

Jan 1, 1954

By Kevin O?Callaghan

Applying Legal Concepts - The Crown must consult, and where necessary accommodate, when: - Crown has knowledge, real or constructive, of the potential existence of Aboriginal rights or title and contemplates conduct that might adversely affect it - Duty to consult is triggered at a low threshold - How much consultation necessary? - Proportional to the strength of claim and potential impact - Spectrum: notice to direct involvement in decision making - Not duty to agree or to get consent (no veto) - Reciprocal: Duty requires good faith and sincere engagement on both sides Role of Proponents: Crown may delegate procedural aspects of its legal duty

May 1, 2010

By C. J. Sullivan

"The outlook for supplying the world's metal needs in the next twenty-five years is good, although in several cases basic costs are likely to increase with rising demand. Metal prices calculated at a constant dollar from 1900 to the present show that for nickel, copper, silver, lead, zinc and tin, prices -and presumably production costs -fell from 1900 to the early 1930s. Since then, they have generally risen, apparently reflecting some depletion in relation to demand. This tendency has been accentuated since the post-World War II adoption of managed, full-employment, growth economics, which have resulted in a sharp escalation in world demand for metals. (Abandonment of such policies, apparently now under consideration in North America, would, of course, affect the pre-dictions of this paper.) Nevertheless, metal prices generally are still below those prevailing in 1900. Exploration potential exists for disseminated ores of many metals still thought of as characteristic of lode and vein deposits. These include uranium, silver, gold, tin and nickel and, to a lesser extent, lead and zinc. Considering the discovery potential for some principal metals in relation to expected demand and prices, I would tend to rate them as follows: molybdenum, zinc, lead, uranium, silver, gold, tin, nickel and copper."

Jan 1, 1970

By Garston Blackwell

Abstract - During geostatistical estimation of block grades, the kriging process produces a measure of error, the kriging variance or the kriging standard deviation. Estimation of the block error depends on the semi-variogram model for a deposit, which reflects fundamental characteristics of a deposit such as (1) nugget effect, (2) range of influence of grades, (3) different local spreads of data as a function of average grade (proportional effect), (4) nested structures, and (5) underlying anisotropies in the data; this model may be affected by sampling or assaying limitations, however. Because the kriging error incorporates so many features of both the deposit and data to be used for estimation, it may offer a substantial improvement on block classification over traditional procedures such as data density. Practice indicates that the relative kriging standard deviation (RKSD) is particularly useful for block classification in measured, indicated and inferred categories. Plots of RKSD in plan and section also can be used to demonstrate where extra drilling and sampling would be most advantageous for upgrading the class of some blocks. Moreover, the use of grade and RKSD filters can show where material near cut-off grade is poorly defined, indicating sampling target areas to improve block classification in the vicinity of the ore-waste boundary.

Jan 1, 1998

By C. I. Godwin

"The relative-value (R-value), discrimination-factor (D-factor), and vector-ratio (V-ratio) method (RDVM) provides a geological knowledge-based statistical and geological-genetic interpretation scheme for geochemical data that enhances discovery in geochemical exploration. The practical advantage of RDVM is that it synthesizes geochemical features geologically related to ore-deposit discovery in three steps: reclassifying element concentrations using log-probability plots into R-values; calculating geologically defined D-factors from R-values; and determining V-ratios. D-factors are the sum of R-values, divided by the number of R-values summed. Based on the analyses selected, D-factors mimic rock or mineral deposit signatures. V-ratios refine interpretations of rock type and vector to orebody locations.RÉSUMÉ La méthode de la valeur relative (valeur R), du facteur de discrimination (facteur D) et du rapport de vecteurs (rapport V) (RDVM), fournit un schéma d’interprétation des données géochimiques basé sur les statistiques et les connaissances géologiques et la génétique géologique; ce schéma contribue aux découvertes en exploration géochimique. L’avantage pratique de la RDVM est qu’elle fait la synthèse des caractéristiques géochimiques reliées géologiquement à des découvertes de gisements de minerais en trois étapes : une reclassification des concentrations des éléments au moyen de courbes de probabilité logarithmique en valeurs R; un calcul des facteurs D définis géologiquement à partir des valeurs R et la détermination des rapports V. Les facteurs D sont la somme des valeurs R divisés par le nombre de valeurs R additionnées. Selon les analyses choisies, les facteurs D imitent les signatures de la roche ou des gisements minéraux. Les rapports V peaufinent les interprétations des types de roches et dirigent vers des emplacements de gisements."

Jan 1, 2016

By John F. Dougherty

Recently, there has been much debate as to the relevance of reporting financial results using the conventional accounting systems, which is based on historical costs, during a period of rapid inflation. In the following paragraphs , the symptoms, if not the causes, of inflation, its detrimental effect on the financial soundness of business in general and the financial reporting changes being advocated to overcome perceived weaknesses in the present financial reporting system in accounting for the effects of inflation will be reviewed. Finally, a course of action as a sound approach to the financial reporting problem will be recommended.

Jan 1, 1978

By J. Wong, M. G. Lipsett, L. K. Daneshmend

"Current trends of increased size, complexity, and automation of surface mining equipment necessitate more comprehensive and objective techniques for equipment comparison and selection. The field of reliability analysis provides tools to generate quantitative bases for maintenance and reliability aspects of such comparisons. Results from statistical analyses of failure and repair time data are used to perform the comparison. A case study is presented which analyzes five machines of two different technologies and three different designs.IntroductionThe surface mining industry is currently faced with a rapid evolution in production equipment. The more obvious trend in this evolution is the steady introduction of even larger machines. Parallel, and complementary, to this increase in size is the introduction or adaptation of new technologies. Together, these two trends result in new surface mining equipment designs; these designs are often more complex and may feature technologies that have yet to be proven for the application or at the scale they are now fielded.The prospect of significant automation of open pit equipment is also bound to add complexity to future equipment designs. Semi-automated features, such as drilling controllers (Aquila, 2000), have already been commercialized. Fully autonomous haul trucks have been demonstrated in open pit mines (Jackson and Zoschke, 2000). Design concepts for comprehensive teleoperation of open pit operations have been formulated (Lipsett, 1998).With this rapid availability and deployment of new technology and equipment, managers and maintainers are faced with a multitude of decisions regarding what equipment to acquire and what maintenance strategies to implement. In light of this evolution in mining equipment, it is necessary to develop better methods for making equipment management decisions (Dessureault et al., 1999; Paraszczak, 1999). The incentive for development of such techniques is that a large portion of an open pit mine’s operating cost is maintenance related, as shown in Table 1."

Jan 1, 2000

By Y. Duna

The reliability of mine ventilation systems is critical to normal and safe production in a mine and includes reliability of the following parts: ventilation system branch (or passage), ventilation structures, ventilation network, and the fan. Among these, the reliability of a ventilation branch may be considered the foundation of the whole ventilation system. The branch ventilation flow includes four parameters: air volume; toxic and hazardous gas concentrations; temperature, and dust concentration. The calculation model for the reliability of a branch was established based on the analysis of normal distribution of flows in any one branch. Then, the efficiency of the ventilation structures and fire risk compromising the reliability of branch was studied. The results obtained were as follows: if the air volume, toxic and hazardous gas concentrations, temperature and coal dust concentrations of the branch are within reasonable limits, set at any stable state and at the same time, then this branch is reliable.

Aug 1, 2013

By T. R. Kostecki

"Instrumented rock bolts are effective tools for assessing the reinforcement and condition of immediate roofs; however, instrumentation can have relatively high costs, which can be justified by high reliability and repeatable and representative data measurements. The instrument’s durability and operational life are of great importance, along with accuracy, applicability, and usefulness. This paper develops reliability models for three instrumentation technologies used in slotted rebar, drawing data from studies at five underground coal mines. Three case studies demonstrate instrument applicability and usefulness. Finally, two types of instrumented rock bolts are used to determine the direction of bend and maximum bending strain. RÉSUMÉ Les boulons d’ancrage instrumentés sont des outils performants qui permettent d’évaluer la consolidation et la condition des toits immédiats. L’instrumentation peut cependant se révéler très onéreuse, des coûts qui se justifient par sa fiabilité élevée ainsi que par des mesures de données reproductibles et représentatives. La durabilité de l’instrument et sa durée de vie opérationnelle sont très importantes, de même que son exactitude, son applicabilité et son utilité. En s’appuyant sur des données issues d’études menées dans cinq mines de charbon souterraines, cet article développe des modèles de fiabilité pour trois technologies d’instrumentation utilisées pour des barres d’armature nervurées. Trois études de cas démontrent l’applicabilité de l’instrument et son utilité. Enfin, deux types de boulons d’ancrage instrumentés sont utilisés pour déterminer la direction de la flexion et la contrainte de flexion maximale.INTRODUCTION Using instrumented rock bolts to monitor strain changes in a rock bolt array allows engineers to understand the per-formance and effectiveness of the rock reinforcement system and the response of the rock mass to such support; however, instrumentation remains a niche solution for solving complex ground-control problems—particularly for underground coal mines, which is where they are needed most. From 2000 to 2016, fall-of-ground fatalities still accounted for an average of approximately 30% of the total annual underground coal mine fatalities in the United States alone (United States Department of Labor, 2018). These tools would also be useful for deep hard-rock mining conditions. The main reasons for the lack of widespread use are not only cost but also accuracy, applicability, implementation procedures, intrinsic permissibility, and reliability (Peng, 2015). As a result, measurements of coal mine roof behaviour using instrumented rock bolts are quite scarce, not widely published, or inadequately presented to provide a seamless understanding of a roof’s response to support."

Jan 1, 2018

By L. K. Daneshmend

"Competitive pressures dictate that the mining industry moves to larger mobile underground haulage equipment with more advanced equipment mechanization, higher levels of autonomous operation of machines, and longer periods between access by maintenance personnel. Since such new machines will of necessity be more complex than existing designs, machine reliability has become a key issue in progressing toward advanced mobile underground haulage equipment. Reliability and maintainability models of such equipment are practically non-existent in the literature. This paper addresses the issue of reliability and maintainability of mobile underground haulage equipment on two fronts: reliability modelling to enhance decision making for maintenance planning; and reliability simulation to enable evaluation of more rigorous production planning scenarios. A case study from a gold mine in the Chilean Andes is presented, for which reliability models of mobile underground haulage equipment, specifically load-hauldump vehicles and underground haul trucks, are developed, and a reliability-based simulation implemented. IntroductionMaintenance accounts for 20% to 35% of the overall operating budget for a typical underground operation, and hence represents the largest portion of the mine’s controllable operating costs (Cutifani et al., 1996; Campbell, 1997; Goddard, 1998). This, coupled with the fact that industry today is faced with an ever more complex and demanding marketplace, has led to an increasing interest in methods to reduce maintenance costs.Although significant effort has gone into developing effective maintenance strategies for industry in general, application of these to the"

Jan 1, 2003

By E. B. Wilson

"Although the Operations Research technique of Reliability Theory has been applied with marked success in many fields, including the Apollo spaceship programs, the concept of reliability has not been generally adopted in mining and other heavy industries. Of course, reliability, or the probability that a system will be able to operate without a failure for a given interval of time, does not require the same emphasis in mining as in the aerospace industries. Nevertheless, certain aspects of Reliability Theory can be followed advantageously. For example, reliability calculations can determine the best time to overhaul and whether to retain stand-by units.The usefulness of the pseudo-operations research technique known as Replacement Theory is more readily re-cognized by the maintenance engineers in mining and other heavy industries. One of the least complex models enables the optimum Lifetime of an asset to be determined."

Jan 1, 1970

By J. F. Perreault, J. Paraszczak

"The profitability of an underground mine depends to a great extent on the production cost.Random equipment failures and their consequences have significant influence on the total operating cost of a mining system. Having this in mind, a reliability study has been initiated for loadhaul- dump machines in an underground mine. The main purpose of this study is to identify the critical machine subsystems, determine their failure pattern and help work out an effective maintenance strategy. In the first part of this study, the failure data of diesel powered LHDs, gathered during an I8-month period have been analyzed. For the purpose of the analysis, the machines have been treated as systems comprising seven subsystems connected in series. The most critical subsystems, i.e. electrical and hydraulic, were further investigated, and analyzed by graphical and analytical methods. Different failure distribution models were applied and discussed. Basic Defmitions and ConceptsIn order to avoid confusion, several terms used in this paper are defined below, as compiled by O'Connor (1991). The acronymsBS and MIL-STD stand respectively for: British Standard and US Military Standard.Failure: the termination of the ability of an item to perform a required function (after BS 4778).Time Between Failures (TBF): the length of time between two consecutive failures.Observed Mean Time Between Failures (MTBF): For a stated period in the life of an item, the mean value of the length of time between consecutive failures computed as a ratio of the cumulative observed time to the number of failures under stated conditions (after BS 4778).Maintenance, Corrective: The actions performed, as a result of failure, to restore an item to a specified condition (after MIL-STD-721 B).Maintenance, Preventive: The actions performed in attempt to retain an item in a specified condition by providing systematic inspection, detection and prevention of incipient failure (after MIL-STD-721B)."

Jan 1, 1994

By G G. Suffel

T HESE remarks on the occurrence of strata-bound massive sulphide deposits are submitted be-cause the writer recently visited the principal Cyprus deposits (in January, 1965) and has also a back-ground of many years spent largely in detailed observation and map-ping of the Horne and Amulet ore-bodies, now largely inaccessible. They are particularly related to the Symposium papers (September Bulletin) by Hutchinson and by Roscoe. Some comments are offered on the cupriferous pyrite deposits of Cyprus. As the writer is currently reviewing the published literature on the related deposits in Turkey, a brief account of some characteristic Anatolian sulphide occurrences is given. The discussion is closed with some thoughts on the relationship between these Mediterranean sulphide deposits and those of northwestern Quebec and the Superior province in general. The geology of Cyprus, as it relates to the sulphide deposits, is well summarized by Hutchinson (1965). After visiting Mavrovouni, Skouriotissa and Limni and after much thought on the possible ge-nesis of these ores, it seems quite logical to me that he is right. They are indeed closely related to late-stage submarine volcanism.

Jan 1, 1965

By G. W. Brooks

This short article is quite different to the general run of papers that are presented to the Institute, but no apology is offered because I consider that first-aid and mine-rescue work are of equal importance to many other subjects that are dealt with in our Transactions. Members of the Institute should be as much interested in the safety of persons engaged in the mining industry as they are in the practical methods of modern mining. We must not only do our best to conserve life and property by adopting every known device to that end, but we must also prepare ourselves so that we may take prompt and effective action when life is in danger, or when property is subject to loss. The need for such preparation in Alberta is perhaps greater than in most places where mining is carried on, and we must spare no effort to assemble at every mine men who are well trained in first-aid and mine-rescue work. The large area over which the mines are distributed renders central training stations out of the question, hence the need for local rescue-teams. Hospitals with skilled staffs, close enough to the mines to be convenient, also seem to be out of the question; therefore the greater need of a high standard of first-aid training for the people in our mining camps. The Government mine-rescue cars are supplied with the equipment necessary for training persons in this essential work and also for dealing with disasters should they occur. The question then arises: are there a sufficient number of men who are trained ? If so we can rest assured that what is possible to be done will be done. But if a sufficient number of trained men are not available much loss of life and damage to property is likely to result.

Jan 1, 1925

By Ernest Becker

Golder Associates provided overall radiological direction and assistance to the client in their interactions with the Canadian Nuclear Safety Commission and operational radiation protection services for the remediation of a calciner that had been used to process uranium. The project was somewhat unusual in that the radioactivity from within the calciner room was removed from the site and the cleaned steel recycled. The presence of yellowcake within the process equipment required stringent radiation protection measures. This project was completed successfully with minimal radiation exposures to the workers and the effective protection of the environment.

Aug 1, 2010