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By Robert A. MacGregor

"Following several months of test work, water leaching in mined-out areas at Stanrock commenced on a production basis in February, 1963. A combination of fast high-pres-sure washing and rewashing of stopes on a predetermined cycle, and the intermittent sprinkling of low-grade heaps, using both fresh water and recirculated acid water, has proved most successful. There was also a correlation of daily sampling data points to a relationship between the leach water grade and the grade of the material being washed, the leaching time and the location along the dip. An increasing tolerance for uranium by the acid-producing bacteria is also indicated. A steady production rate of 10,000 to 12,000 lbs. of u.08 per month is being maintained, with an over-all mine water grade of 0.25 lb. per ton and a pH of 2.3."

Jan 1, 1966

By M. S. Badollet

Introduction Very little fundamental research has been done on asbestos fibre to cake maximum advantage of its properties and to determine in what commercial products it can best be utilized. For the research chemist who is associated with asbestos development work, a thorough study of mineralogical information on asbestos deposits would furnish reliable information on the rock formations and the mineral impurities closely associated with the asbestos. Furthermore, ?he must have an intimate knowledge of the uses of the fibre in various products so that he can visualize the importance of the fibre and the role it plays in industry. Some of the properties of asbestos fibres such as strength, composition, length, harshness or softness, and mineral associates are of considerable importance to the manufacturer because they are responsible for many production difficulties. Fibre Strength It has been known for some time chat asbestos filaments have considerable tensile strength. These strengths have been referred to merely as 'weak' to 'very strong'. Not until recently have numerical values been applied to the strengths of asbestos fibres. But today we can take a thin fibre filament and mount it between two holders and apply a gradually increasing load or pull until the fibre breaks. By measuring the cross sectional area of the filament and the amount of load applied, we can calculate the tensile strength of the fibre in terms of pounds per square inch. This type of test is slow and rather difficult, but the fundamental data obtained furnish important basic information that can be applied to mechanical processing equipment and to certain asbestos products.

Jan 1, 1948

By Bruce A. McFarlane

"I WOULD LIKE TO SAY how honoured I am that I have been invited to participate in this panel discussion. I have taken the liberty of narrowing my topic somewhat so that instead of speaking on the Sociology of Professions as a whole I will speak on one aspect of it, that is, on Manpower Problems in the Minerals industry of Canada, with some reference to a new social role for the professionals engaged in this industry. This probably means that I will be encroaching on areas covered or to be covered by other speakers, but I hope that when I do so I will do so from a slightly different vantage point. That is, from a sociological perspective rather than from a historical, industrial, business or professional perspective. I plan to divide my discussion into three areas, namely: (i) problems of ownership and control; (ii) environmental problems; and (iii) manpower and recruitment problems. I do not plan nor am I able to provide clear-cut solutions to the various problems I raise under these three headings. Rather, I hope that my discussion of the problems may form the basis for an extended discussion here and elsewhere. Because of the limitations of time, I will only briefly discuss the first two problem areas noted above – (i) ownership and control and (ii) environmental problems - and I plan to concentrate on the manpower issue."

Jan 1, 1972

By R. L. Guerguerian, Eugene Bercel

"Grinding mill hydrostatic trunnion bearings require an external pumping source to provide and maintain the oil film between the bearing members. In order to guarantee a predetermined minimum film thickness, the lubrication system tends to be oversized. The oil film is ""indirectly"" controlled by flow, pressure and temperature monitors with fixed settings on the conservative side. This can lead to excessive maintenance and abbreviated life for the lubrication system components. A reliable method of monitoring actual film thickness would not only provide greater mill availability, but also minimize maintenance costs.This paper describes the instrumentation installed in Dominion hydrostatic bearings, and presents results of field tests where the output of that instrumentation was recorded under various operating conditions.IntroductionThe trend toward larger and more sophisticated grinding mills has made the operators of these machines increasingly vulnerable to financial loss, as the cost of downtime and repairs has increased directly with machine size. In order to guard against such losses, it is becoming imperative that large, sophisticated grinding mills be equipped with protective instrumentation to monitor some of the critical operating parameters and to identify events and trends which, if they go unnoticed, can lead to excessive maintenance costs and machine downtime. The idea of protective monitoring systems is not new. The operators of certain types of machinery where a high degree of safety is required or where machinery health can deteriorate very rapidly, as in the case of high-speed turbo-machinery, have long been using protective instrumentation on their machines. The increased awareness of the benefits of monitoring machinery conditions and the availability of reliable and relatively low-cost instrumentation of a large range of sophistication is making the practice now widespread. Traditionally, grinding mills have not been considered as high-risk machinery requiring instrumented protection. However, the trend, mentioned earlier, toward employing fewer, but larger capacity, mills increases the risk of significant disruption of production, and therefore measures to minimize the risks are desirable."

Jan 1, 1981

By M. H. MacLeod

"IntroductionTHE ORE PASS raise system at the H.B. mine as contracted by the Patrick Harrison Company consisted of two raises 6 ft. by 10 ft. in section •at 60 degrees to the horizontal. No. 88-88 raise, the longer of the two, was a straight raise 690 feet long, with access only from the bottom. In addition, this raise had two branch knuckle-backs only one of which was driven by. the Patrick Harrison Company. The other, known as 88-89 raise, was 540 feet long with knuckle-backs at 280 feet and 410 feet. Its access, also, was from the bottom (see Figure 1)."

Jan 1, 1954

By W. Holdsworth

The flotation mill of Dentonia Mines, Limited, at Greenwood, B.C., went into operation on April 20th, 1934, and by October 11th a total of 15,000 tons of ore had been treated. It is intended in this paper to describe briefly the operation and to give some of the operating data which have been gathered. The metallic minerals in the Dentonia ore are pyrite, chalcopyrite, galena, and, occasionally, native gold, and the gangue includes chloritic material, vein quartz, and calcite. Pyrite makes up about 90 per cent of the metallic content of the ore, in which it is disseminated as irregular grains and well-formed cubes. An average analysis of the ore is: gold, 0.27 oz. per ton; silver, 1.73 oz. per ton; copper, 0.12 per cent; lead, 0.31 per cent; and zinc, trace. From the mine ore-bin, situated near the portal of the tunnel at the mine, the ore is hauled by motor truck to the mill, a distance of three-quarters of a mile, and there dumped into the receiving bin, which has a capacity of fifty tons. The hauling is done during one eight-hour shift, commencing at 7 a.m. The maximum size of the ore fed to the mill-bin is ten inches. Lumps larger than this are broken by sledge hammer to pass through grizzly bars, spaced ten inches apart, installed above the bin. The ore is drawn from the bin by a 30-inch, 6-ply conveyor belt, 18 feet 6 inches long. In the near future, when the cross-cut tunnel is completed, the ore will be trammed to the receiving bin. This will effect a considerable saving in cost. At the same time, the bin will be set back several feet, so that the length of the conveyor belt may be doubled. This will make efficient ore-sorting possible, and so ensure a minimum of waste rock in the mill feed.

Jan 1, 1935

By R. A. Gannicott

Trend surface analysis was used to investigate the geochemical dispersion patterns of Si, Ai, Fe, Mg, Ca, Na, K, Ti and Rb in the footwall of the Seneca massive sulphide prospect in southwestern British Columbia. Surfaces for various element ratios were also produced to see if the distributions of the elements are related to each other. Trends developed by the elements redistributed during hydrothermal alteration may be difficult to detect for various reasons, such as too few and widely separated sample points, random analytical errors or local variations in rock chemical composition that are not related to regional trends. Trend surface analysis is useful to distinguish regional trends from local fluctuations. The computer program used in this study is capable of calculating surfaces up to the 6th degree polynomial, but provides for automatic termination when the variables in the equation for successive surfaces become effectively collinear. With the relatively small number of data points used (21 samples) in this study, such termination occurred after the quadratic surface. Results show that, at the Seneca prospect, Mg and K increase, and Na and Ca decrease, toward a common centre which corresponds closely with the best drill-core intersections of ore. The centre is interpreted as a volcanic vent and as the source of mineralization . Quadratic surfaces for element ratios show that K/Ca decreases and Fe/Mg increases away from this vent. Thin-section and X-ray diffraction analyses indicate that these variations reflect sericitization of plagioclase and an increase in the Mg content of chlorite near the vent. The mineralization , rock types and element dispersion patterns at the Seneca prospect are similar to those reported for volcanogenic massive sulphide deposits at Bathurst, New Brunswick, and in the Hokuroko district of Japan.

Jan 1, 1979

By Robert Dickson

Princess colliery is operated by Old Sydney Collieries, Limited, a direct descendant of the General Mining Association of London, England, which, in the first quarter of the nineteenth century, pioneered in coal mining in Nova Scotia. The coal worked is a 5 ft. 6 in. seam known generally through the Sydney coalfield as the Harbour seam but referred to locally as the Sydney Main. Entry is made by shafts, 680 feet deep, sunk in 1871 on a headland forming the northern entrance to Sydney harbour. From them extend the main roadways of the colliery, a distance of 700 feet to the shore line and a further distance of 14,700 feet in submarine areas to a total length of 15,400 feet. It was the first colliery in Nova Scotia designed to work submarine areas. Lateral development extends across a frontage of 16,000 feet and the submarine area from which the coal has been extracted is slightly over 6 square miles. There yet remains sufficient territory ahead of the workings to assure a future life to this colliery estimated at over 80 years at the current rate of production. In this area the seam dips at 6 to 7 per cent and face workings have reached a depth of 1,690 feet below the sea level. Until 1923 extraction of the coal was by room-and-pillar, followed by the drawing of the pillars. At that date the superincumbent strata had reached a thickness of 1,400 feet, resulting in heavy weighting on the roof and severe side pressure on the coal ribs. In combination with a soft, heaving pavement this created a set of conditions involving great difficulties and expense in keeping open places driven in the solid sufficiently long to permit recovery of the coal in the pillars by methods and equipment then available. The operator was forced to resort to extraction by longwall as the only economical method of winning the coal.

Jan 1, 1948

By Knud Sinding

Many industries have established their own systems for self-regulation. They often do so when companies operate in countries where financial, technical, environmental and social regulation is weak and when the industry is challenged by legitimacy issues related to behaviour in one of these areas. Mining is one industry that has progressed unevenly down the road of self-regulation in these areas. This paper examines how the development of self-regulation for mines and mining companies involves difficult questions of scope, rules, membership, assessment criteria and performance evaluation. Using a range of theoretical and empirical results from research on self-regulation, performance rating and corporate strategy, this paper analyses the strategic and operational issues related to the idea of self-regulation in the mining industry. The analysis indicates that while self-regulation may bring benefits to members, they are likely to take a long time coming; but when they do arrive they may be substantial. Using the fact that in relation to technical and financial issues the industry is quite experienced in self-regulation ? not least as it is more reluctant in areas such as environmental and social performance ? the case is made for a comprehensive and innovative approach, that draws on the areas where the industry is experienced and develops new institutional solutions in the areas where the industry is more reluctant.

Aug 1, 2013

By H. Chaouki

The aim of this work is to simulate the forming process of a green anode. For this purpose, a nonlinear compressible viscoelastic constitutive law is presented. The concept of natural reference configuration is considered. Within an isothermal thermodynamic framework, a Helmholtz free energy is proposed to take into account the nonlinear compressible deformation process occurring between natural reference configuration and current configuration. A dissipation potential is introduced in order to characterize the irreversible aspect of compaction process. Thus, the constitutive law is formulated through two equations: 1) an expression of Cauchy stress tensor and 2) a differential equation characterizing the evolution of the natural reference configuration. Material parameters are assumed to be a function of the bulk density. This allows capturing the micro-mechanical phenomena within the chosen macroscopic approach. An experimental study based on compaction tests is carried out in order to characterize the mechanical behaviour of the anode paste. A user's material VUMAT subroutine for finite element dynamic explicit analysis has been developed and implemented in the ABAQUS commercial software. To evaluate the model predictive capability, numerical simulations of the compaction forming process of anode paste were performed. Simulation results show that the constitutive law predicts the experimental trends and gives interesting physical responses. This constitutes a first step toward making a benchmark with experimental results on the forming process of anode paste.

Jan 1, 2011

By Mike Broczkowski, Laura Dewhirst, Kieran Large, Angelo R. Fernando, Heather Daigneault, Jim Johnson, Randy Wiens

The radioactive isotope radium 226 is a contaminant of potential concern in effluent waters from metal mining operations in Canada. Acceptable release levels of radium 226 are governed by Metal and Diamond Mining Effluent Regulations. Since radium is invariably present as a companion element in uranium ore, monitoring and controlling of radium 226 is a must for uranium mining operations. Measurement of radium 226 is traditionally carried out through a radiochemical technique involving selective co-precipitation of radium with barium sulphate followed by alpha spectroscopy for quantification. As of 2010, Cameco has also been using an ICP-MS based radium analysis method developed in collaboration with a research team at Trent University, Peterborough, Ontario. This method, which is highly automated and requires significantly less sample handling, with improved turn-around-times, is being used by Cameco site laboratories at the McArthur River and Cigar Lake mines as well as the Port Hope Conversion Facility. This paper compares the benefits and drawbacks of this new method, compared to the traditional alpha counting procedure drawing from almost ten years of field experience.

Jan 1, 2020

By R. C. Gilmore, J. F. Brune

"Pulverized limestone rock dust used in United States underground coal mines to prevent and suppress coal dust explosions must easily disperse by forces of a methane or coal dust explosion. Moisture in the mine environment causes caking of the dust. Colorado School of Mines researchers performed dispersibility tests in a full-size explosion test drift. Tests included conventional, hydrophobized, and rock dust approved for German mines. Conventional and German standard rock dust products partially agglomerate, which may not be effective in suppressing a coal dust explosion, while hydrophobic rock dust retains better dispersibility.INTRODUCTIONA coal dust explosion devastated the Upper Big Branch mine in 2010 resulting in the death of 29 miners, the worst mining accident in the United States since 1972. The explosion propagated through approximately 65 km of active mine workings, but was extinguished in areas that had been properly rock dusted (Page, 2011). Researchers have long studied and established the ability of inert limestone rock dust to suppress coal dust explosions, see Richmond et al. (1975), Cybulski (1975), and Sapko et al. (2000).To be effective, rock dust must contribute to a total inert content of > 80% by weight and 100% of rock dust particles must pass through an 850 µm sieve, while 70% of the rock dust must be finer than 74 µm. This is established in US regulations 30 CFR §75.2. Dry rock dust is a nuisance that prevents mining work downwind from rock dusting activities. To overcome this problem, dust manufacturers have proposed applying the rock dust as a wet slurry or foam. After drying, manufacturers expected the slurry or foam-applied dust to have the same explosion suppression capabilities as dry-applied rock dust.Researchers at the Colorado School of Mines (CSM) designed and built a full-scale, underground Explosion Test Facility (ETF) at the CSM Edgar Experimental Mine in Idaho Springs, Colorado about 20 miles west of the CSM Golden, Colorado campus. To disperse the different rock dust products, researchers produced an air pressure pulse using a mesh array of PETN detonation cord. This method is simpler, more reproducible and safer than other methods considered, including methane-air explosions and a compressed air cannon. The detonation cord blasts produce a wind velocity of 30 to 50 m/s, the minimum velocity at which coal dust explosions can propagate, based on research by Nagy (1981) and Cybulski (1975)."

Jan 1, 2019

By M. G. Lipsett

"Mining properties are becoming increasingly remote, a challenging situation for operating and maintaining equipment. Logistics of transporting workers and materials can be alleviated by having timely, accurate information of equipment location and operating condition, and by automating some activities. This paper discusses an infrastructure for remote operations, with strategies for communicating different types of data, and a design method so that systems can interact with either an operator or another system. A remotely operated excavator prototype is described, with on-board performance and diagnostic monitoring systems now used on production equipment. IntroductionSyncrude Canada Ltd. operates an openpit oil sands mine near Fort McMurray, Alberta. For twenty years, draglines and bucketwheel reclaimers have fed conveyors that transport dry oil sand to an extraction and upgrading plant. In converting to a truck and shovel operation, Syncrude has developed slurry pipelines and bitumen froth pumping to allow more remote leases to be mined more than 30 km from the base plant.There are organizational and resourcing challenges in operating and maintaining equipment in three nearby, but separate, mines. The logistics of transporting workers and materials to production and support equipment become more difficult, and operations and maintenance personnel and facilities become more distributed. Supervising mine operations will rely even more on having timely, accurate information about equipment location and operational status.Syncrude is typical of an open-pit operation. Voice communications are the preferred way to exchange information for making immediate decisions about operations and maintenance. A large number of narrowband FM broadcast radio channels keep teams of miners working together. Haul truck drivers, shovel operators, and dispatchers talk on one channel while maintainers coordinate activities with the control tower on another. Cellular phones have become popular for supervisors who have to talk with planners and engineers in offices without radios."

Jan 1, 2000

By R. Esteban, D. Runnels, J. Torrealba-Vargas, G. Couture

"Data handling is an important step in the development of a simulator of a mineral processing circuit. The model requires representative data of the scenario to be modeled. The model development involves protocols that must be followed very closely to complete a successful project.Data handling of large and diverse datasets (metallurgical test results, geological data, mining models, historical data, etc.) is a key element of the model. The information needs to be processed, reconciled, interpreted, modeled and presented to support the design or the optimization of a mineral processing plant.Best practice recommends that teams from different disciplines (such as mining, metallurgy, geology and environmental) interact to define the most important variables that could influence the simulator. For example by adopting a geometallurgical approach in the earlier stages of the project, it is possible to consolidate the number of main ore rock types in a testwork program (saving money and time) by involving geologists and metallurgists in the sample selection and data interpretation.Planning the development of a model involves an understanding of the software capabilities but also the limitations and the magnitude of the data required to calibrate the model in case of changes in the project.A successful model requires a deep understanding of the circuit to be modeled and thus plant personnel should be considered as members of the team.This paper describes the use of the "state of the art" tools for data analysis, simulation and optimization; and shows three practical examples of the use those tools in the design of mineral processing plants."

Jan 1, 2015

By J. M. Ríos

"Without conscious effort and understanding, a number of factors unique to mineral exploration often hinder building sustainability in host communities. These include the episodic and transitory presence of an exploration team in the community and the inherent uncertainty of outcomes— most projects fail from an exploration perspective. Experience in rural communities across Mesoamerica, however, has shown that it is possible to go beyond pragmatic philanthropy and infrastructure improvements to promote positive, sustainable outcomes in communities. Examples are provided of lessons learned and proven practices that improve quality of life and support a strong social license to operate.RÉSUMÉ Sans une compréhension et un effort réfléchis, de nombreux facteurs uniques à l’exploration minérale nuisent souvent à l’établissement d’un développement durable dans les communautés d’accueil. Ces facteurs comprennent la présence épisodique et transitoire d’une équipe d’exploration dans la communauté et l’incertitude inhérente des résultats – la plupart des projets échouent après l’étape de l’exploration. L’expérience dans les communautés rurales à travers la Méso-Amérique a toutefois démontré qu’il est possible de dépasser la philanthropie pragmatique et les améliorations des infrastructures pour promouvoir des résultats positifs et durables dans les communautés. Des exemples qui améliorent la qualité de vie et soutiennent un solide permis social d’exploitation sont présentés; ils sont tirés de leçons apprises et de pratiques éprouvées."

Jan 1, 2015

By Brian Raymond

This paper will outline the problems and solutions of the new generation washeries, as well as the recent technological advances which are being considered for future coal preparation plants. The subjects to be covered will include: - reasons for considering coal preparation plants; - raw coal crushing and handling systems; - types of coal cleaning equipment being used versus new equipment being considered; - fine coal circuit sizing; - clean coal centrifuging and dewatering; - thermal dryer problems and changes; - fine refuse dewatering systems; - clean coal storage problems and changes; - materials handling within the plants; and - control systems for preparation plants. The design and integration of the various circuits that form a modern coal preparation plant have led to the creation of an exciting new field of industrial research. As the need for energy sources increases, efficient methods of preparing coals for specific markets will become more important.

Jan 1, 1979

By Edouard Asselin, Tasawar Javed

The precipitation of hematite from ferric sulphate - cupric sulphate - lithium chloride acidic solutions was studied in a batch reactor. The effect of several variables on the extent of hematite precipitation as well as on its crystallinity and purity was investigated. The variables studied include: initial ferric concentration (1.5 - 30 g/L), retention time (0 - 12 h), initial sulphuric acid concentration (0 - 30 g/L), temperature (150 - 220 °C) and chloride concentration (0 - 25 g/L). The results show that hematite is preferentially precipitated at lower initial iron concentrations. Longer retention times increased the fraction of hematite in the precipitates but did not affect its crystallinity to a significant extent. On the other hand, higher temperatures increased the purity and crystallinity of the hematite. At lower acid concentrations hematite and goethite were precipitated. However, only hematite was precipitated when the initial acid concentration was > 12.5 g/L. Better crystalline hematite was formed at lower acidities. Increasing chloride concentration increased the amount of hematite and decreased the amount of iron sulphate hydroxide phases, but did not affect the crystallinity of the hematite.

Jan 1, 2015

By Atsushi Sainoki

Blast vibration induced by mining activities, such as stope production blasts, could lead to the initiation of seismic events that inflict damage to mine openings. In this paper, the effect of stope production blasts on nearby fault is examined. First, validation of blast vibration attenuation is performed with a numerical model representing a single blast hole through comparison with that calculated from charge-weight scaling law derived from in-situ data. Subsequently, a mine-wide scale model with a fault parallel to a steeply dipping, tabular ore deposit that is mined out with sublevel stoping method is generated, and the stopes are extracted and backfilled with static analysis to simulate burst-prone conditions on the fault. Based on the stress states, dynamic analysis is performed, in which blast vibration is applied to grid points on a stope wall on the hanging wall side. This assumes 9 blast holes located close to the wall, and blast-induced particle velocities that consider the positional relationships between the assumed blast holes and the stope wall are applied. During the dynamic analysis, blast sequence is considered, and stress states and shear displacement on the faults are examined. It is found from results that, after a rise in normal stress on the fault due to compressive waves induced by the blasts, the normal stress decreases because of the reflection of the compressive waves on the fault. The reduction in the normal stress due to the reflected waves is found to be large enough to cause the fault to slip. The results also show that the level of normal stress eventually keeps decreasing with time as the blast sequence proceeds and that an increase in shear displacement on the fault is accompanied by a decrease in normal stress. This study clarifies the mechanism by which blast vibration causes the fault to slip. In addition, the simulation technique to apply blast vibration that takes into account blast sequence and the locations of blast holes to a stope wall is developed.

Aug 1, 2013

Barrick Gold Corporation is the gold industry leader, with 25 operating mines and a pipeline of large, long-life projects located across five continents, in addition to large land positions on some of the most prolific mineral districts. Barrick's high level of commitment to sustainable economic development and environmental stewardship was recognized by Dow Jones Sustainability Index (DJSI) - World, for the third consecutive year in 2010. The potential for adverse environmental effects from acid rock drainage (ARD) and metals leaching (ML) and their financial implications for Barrick are key considerations in our environmental assessment and business development processes. Barrick's membership in the International Network for Acid Prevention (INAP) reflects the importance of these issues to our business. INAP's development of the Global Acid Rock Drainage (GARD) Guide (a best practices guide for acid rock drainage prevention) provides Barrick with an important tool to assist in the assessment of environmental and financial risks from ARD and ML associated with our planned and ongoing mining operations (INAP, 2009). In this paper we will discuss how Barrick incorporates the GARDGuide and its principles for ARD and ML prediction and prevention in our business development processes and the management of our operations. The GARDGuide serves as a key reference for our project environmental assessments and as a common link between our projects and operations management, consulting specialists, permitting and regulatory authorities and the public. We will discuss how the GARDGuide is being "syndicated" throughout Barrick as a standard of practice and present a case study of how it was used in a recent Barrick Business Development Project.

Jan 1, 2011

By J. E. Udd, L. B. Geller

"Mine-shaft wire-rope discard regulations include, among other criteria, a limited amount of permissible loss-of-breaking-strength (LBS). Currently, this parameter is estimated on the basis of non-destrutive-testing (NDT) with electro-magnetic (EM) type instruments. This paper analyses the accuracy with which these estimates have, so far, been obtained in practice.It concludes that while certain types of testers have produced better results than others, the desired accuracy level has not been attained. Also discussed are the putative reasons for this situation, and appropriate actions that the mining industry might wish to take."

Jan 1, 1990