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By M. Myllymäki

"Pre-treatment of mill feed in a minerals processing plant enables for higher production efficiency per ton of product, reduction of consumables and diverting mineral feed types. Sensor based particle sorting allows for pre-concentration of the run-of-mine (ROM) material prior to other concentrating process. Various sensors provide different responses from the minerals in measured particles. The capability of “accepting” or “rejecting” particles based on sensor responses is investigated in specific test work for each project. Modern sorting machines use pneumatic actuators to divert the reject particles from the material stream. This paper discusses the incorporation of ore sorting test work in processing and plant design. When taking the effects of a sorting circuit into account early in the process planning phase, the downstream process can be adequately sized and impacts evaluated. Potential benefits include but are not limited to increased head grade, lower tonnage to the mill, increased mining operations, removal of deleterious elements and changed properties in the process feed. In a case study we present the Keliber lithium project in central Finland. The plant will produce 9000 tons of lithium carbonate per year from a spodumene ore. Ore sorting and flotation tests were carried out in laboratory and pilot scale. Process models were designed and simulations performed using Outotec’s HSC Chemistry Simulation software. Changes in the flotation performance (grade, recovery, impurity levels) were simulated with and without the pre-concentration of the ROM material. The metallurgical performance and mine economics of the different operational scenarios were evaluated using the Ore-Met optimizer module of the simulation software.INTRODUCTION Challenges in the recent years such as declining ore grades, increasing energy prices, scarcity of water and increasing environmental regulations raise the demand for more efficient processing technologies. Sensor based sorting offers a method for pre-concentration or waste rejection at an early process stage. The technology analyzes each rock particle separately for their unique physical and chemical properties, and diverts the particles into separate material streams by high pressure air jets. Successful implementation relies on ore heterogeneity, differential sensor response and suitable feed preparation."

Jan 1, 2018

By W. D. Watson

"Early in mine development at Quintette Coal Limited major problems were encountered with the fleets of primary equipment which seriously hampered production. These major fleets (cable shovels, hydraulic shovels, hydraulic drills and electric trucks) have consequently been the focal point of maintenance efforts. Some were prototypes in the Canadian mining scene and brought with them new concerns to test their skills. The problems were studied and the category and areas which were having the greatest impact on the reliability of the equipment were determined. Once defined, priorities were established and a program was initiated which was designed to accomplish a resolution. Resulting from implementation of this systematic approach, over the past three and one-half years, the fleets are now giving good reliability and industry standard availabilities. Along with these significant achievements, cost per operating hour on some of the equipment fleets has decreased substantially and continue a downtrend through 1987. This paper identifies the problems and describes the resolutions. IntroductionIn the early years of the mine development, Quintette Coal Limited (QCL) experienced production shortfalls due to problems with the major excavator and haulage fleets. A large fleet of hydraulic excavators had been purchased, and QCL was among the first northern users of all hydraulic blasthole drills. They were also using some prototype equipment and encountered problems which were not common on other types of equipment or were unknown.Because of these unique problems and lack of experience from other mines to draw on, an analytical approach was taken to areas and associated causes of the delays affecting the availability and reliability of equipment. This was done by dividing the equipment downtime into seven classifications of delays, i.e. maintenance, electrical, hydraulic, mechanical, damage, service and preventative maintenance, and tires; and then each was expressed as a percentage of total downtime. Subsequently each of the delay classification was divided into categories e.g. electrical to six categories - wheel motors, main alternator, relays, cards, no propel, lighting and 24 V system. Then, the basis for further study had been established.From this preliminary analysis of historic records, it was possible to determine the areas which were causing the majority of the downtime. These areas were then analyzed to evaluate causes and to determine possible solutions to the problem s. This paper addresses the major fleets, their problems and eventual solutions. Plea se bear in mind that the over-all objectives were to increase physical availability and reliability."

Jan 1, 1988

By T. T. Tigert

INTRODUCTION THE PURPOSE of this article on methane is to present the simple basic facts of the characteristics, detection, occurrence, and control of this natural gas in metal mines, so that operators and .safety men may deal with it with some degree of confidence. Fortunately, although methane has been noted at many metal mines throughout Canada, the occurrences usually are small flows of short duration, and the ignitions experienced have, in most cases, had minor consequences. However, methane does present a hazard that can be of serious proportions, and ?any complacent attitude toward this gas that might exist in the minds .of people engaged in underground mining operations should be dispelled when it is ,pointed out that, in Ontario alone, ignitions of this gas have resulted in at least four fatalities, and eight men seriously injured and burned, during the past three years. lt is well-known that liberation of methane can and does .occur suddenly, often in mines where no gas has been found before, and that many ignitions and explosions have occurred in so called non-gassy mines. In view of this, it is apparent that no mine can, with any degree of certainty, be classified as non-gassy. CHARACTERISTICS OF METHANIZ The characteristics of natural gas encountered in most of the Ontario mines indicate that methane is the chief constituent. Methane (CH4), commonly termed 'marsh gas', and by the coal miner 'firedamp', is a colourless, odourless, and non-poisonous gas considerably lighter than air, and is the explosive gas frequently found in coal mines. Its physiological effects, closely resemble those resulting from nitrogen.

Jan 1, 1951

By Jon Errey, Aleksandar Petrovic, Karl Haase

"Developing a gold deposit of this magnitude in the Amazonian jungle of Guyana posed many challenges. This paper describes not only the process & logistical challenges arising from the remote mine site location in a tropical environment with a local industry unaccustomed to recent large scale gold mining operations, but also the innovative technical solutions employed to address the unique ore body characteristics. The best examples of this approach were dealing with the initial high clay content saprolite ore from the development phase and primary mining pits whilst ensuring that the design also implemented the right method to deal with the future fresh rock in an environmentally sensitive habitat. In order to do this separate individual crushing flowsheets were generated, focusing on the specific material handling equipment that would be suitable to handle these various types of material and ensure high recoveries were maintained.INTRODUCTIONAurora gold mine is located in forested region of Guyana, 170 km west of capital Georgetown, and 130 km West North-West of Bartica, a settlement at the junction of the Essequibo and Cuyuni Rivers.The Aurora gold project (Aurora) is a 5,000 tonne per day open-pit/underground operation, which will produce a total of 3.29 million oz. gold – averaging 194,000 oz. per year – over an initial 17 year mine life. At the final investment decision in 2014 Aurora had a total resource of 6.54 million ounces in the measured and indicated categories (62.83 million tonnes at 3.24 g/t Au) as well as additional 1.82 million ounces in the inferred category (16.93 million tonnes at 3.34 g/t Au)."

Jan 1, 2016

By N. Morrison, I. Holl, R. Welyhorsky, A. Hempstock

ABSTRACT: The Victor diamond mine is located in the James Bay lowlands, 90 km west of the First Nations village of Attawapiskat. The project was the first of its kind in northern Ontario. The process plant was designed to produce a 95 to 98% by weight diamond concentrate through three stages of comminution, dense medium separation, and proprietary X-ray technology for final recovery. The plant was commissioned over a period of six months, commencing prior to substantial completion of construction. Through effective planning of the commissioning phase, the Victor mine start-up was safely completed nine months ahead of schedule.

Jan 1, 2011

By G. S. Hume

FOR MANY YEARS Canada lived in the hope of attaining a substantial production of petroleum and natural gas that, to geologists familiar with the sedimentary basins of this country, seemed an entirely reasonable expectation. There have been surges of exploration activity stimulated by oil and gas discoveries and development such as occurred in Turner Valley. However, it was not until the Leduc field in Alberta was found in 1947, and the significance of that discovery was realized, that the search became really intensive and continuons. Expansion now has become a matter-of-fact attitude based on results which would have been considered impossible of achievement a few years ago.

Jan 1, 1957

By Keith Spence

"The notion of ""value"" has always been a subjective and contentious issue. Indeed, Value is in the eye of the beholder. There are varied methods and practices for valuing property, as there are industries in which they are applied. For example, there are ""replacement value"", ""insurance value, ""salvage value"", ""appraised value"", ""book value"" and ""fair market value"", to name a few, although in the mining industry, valuations usually refer to fair market value.In the Canadian mining industry, at present, there are no comprehensive regulations or guidelines that specify which approaches or methods are appropriate for use in the valuation of mineral projects. In January 1999, The Mining Standards Task Force of the Toronto Stock Exchange and the Ontario Securities Commission recommended that the Canadian Institute of Mining, Metallurgy and Petroleum establish a committee to review and advise on approaches and methodologies for the valuation of mineral properties. Among the approaches to be considered, are included the following: the Discounted Cash Flow Approach, the Cost Approach, the Option Pricing Approach and Market Comparables Approach. In addition, methodologies differ depending on whether the project is at the exploration stage or the producing stage.The CIMVal committee expects that its final report will form the basis for a standard Canadian Code for the valuation of mineral properties."

Jan 1, 2003

By Jeremy G. Berg, James B. Mulligan

"There is a very small fraction of wireless experts in the world with experience in underground installations and an even smaller fraction that have experience specific to building mine shafts. This is why in 2009, Redpath created its own system to meet the demands specific to shaft construction. Today, after a dozen shaft installations and several design iterations, Redpath has the expertise and experience required to implement a proper wireless system in any shaft configuration.This document will explain multiple proven wireless communication designs optimized for shaft construction and suitable for permanent use. This includes line of sight installations up to 1200m, short range mesh networks, and the latest patent pending Integrated Leaky Feeder Mesh Network. Additionally, this document will explore the lessons that Redpath learned in its effort to interconnect the people and tools needed to build a mine shaft.INTRODUCTIONAfter a decade of research, several design iterations and a dozen application examples, Redpath has resolved two wireless network architectures to best serve mine shaft construction projects.The long range line-of-sight (LOS) wireless network is the most cost effective and easiest to install, but requires an unobstructed line of sight between the working area and the shaft collar. As such, long range LOS is best suited for ventilation shafts or during the first phase of shaft sinking, before the shaft is equipped.Alternatively, a mesh network uses radios installed at pre-determined intervals in the shaft and on each conveyance. A wireless mesh uses antennas to bridge intervals between shaft radios, whereas Redpath’s integrated leaky feeder mesh network (patent pending) bridges these intervals with radiating cable, commonly referred to as a “leaky feeder” cable. Both of these mesh configurations can provide continuous reception for hoist conveyances travelling in shafts without line-of-sight, making them ideal for shaft equipping and even permanent installations in both mine shafts and lateral drifts.BACKGROUNDHoist operators receive operating commands using what are commonly referred to as “bell signals.” These instructions are delivered in a series of coded pulses on a spring returned pull cord or push button that is typically hardwired back to the hoist operator’s control room from one of many locations in the mine shaft. During the construction phase of a traditional mine shaft, a worker riding inside the sinking bucket would have to reach out to a pull cord installed on the shaft wall to send a stop command to the hoist operator. Today, Redpath’s modern shaft sinking projects use fully enclosed personnel carriers to protect the workers riding inside, specifically preventing workers from reaching out into the shaft while the hoist is in motion. The enforcement of this safety feature on all shaft projects in 2008 forced the engineering group at Redpath to find a suitable wireless solution for hoist communication to facilitate shaft construction.THE IDEAL COMMUNICATION SYSTEM FOR MINE SHAFT CONSTRUCTIONIdeally, the shaft communication system should not transform the tools to which the miners have grown accustomed. It should support the push-to-talk functionality of traditional VHF handsets and the standard belling system that has been used for decades. Additionally, it should be able to support a vendor independent framework upon which new devices and features can be added. The following paragraphs summarize some of the important requirements Redpath has identified.Support for voice transmission: Low latency is critical to prevent jitter during voice transmissions. The system must be compatible with commercially available mobile handsets and support several simultaneous conversations with the ability to broadcast a voice message to all users on a select channel using a “push-to- talk” microphone and loudspeaker.Transmission of PLC data: Low latency is required to"

Jan 1, 2019

By G. M. Behrend

"The mining and processing of mineral ores is a very old industry which is steeped in tradition. Rising demand for metals has recently forced the exploitation of lower-grade orebodies which require extensive beneficiation. The high capital expenditures involved, together with market pressures for high-quality concentrates and pellets, have forced the development of new process technologies which are heavily dependent on automatic process control. Development of suitable instrumentation has been rapid and it is being applied to mining processes today with a high degree of sophistication. The drive for higher efficiency and profitability goes on and has reached a level at which modern digital computers appear to be the only answer. However, the efficient application of a digital process computer is extremely complicated and is therefore approached by the mining industry with considerable hesitation.Some of the benefits promised by the digital computer can be obtained today by other means, which are more manageable and can provide immediate payoff. The result would be a building-block system which would utilize the digital process computer as its final component, to perform true plant optimization, free from routine chores."

Jan 1, 1971

By E. V. Konopleva, H. J. McQueen

Steels in high variety have been providing strength and ductility for more than a century mainly through complex heat treatments following hot shaping. The economical and sustainable goal was a steel with the two operations combined through applying knowledge of dislocations and strengthening mechanisms aided by new mechanical and microstructural techniques. Primary hot reversing-mill rolling produced static recrystallization (SRX) between every pass to significantly finer grain size. Hot torsion showed that with lay-on temperature and rate of reduction suited to gradual precipitation of minor additions of Nb, the austenite grains would become highly pancaked; the existence of very fine subgrains along the grain boundaries (GB) could be deduced from tests on stainless austenite. The HSLA strip had to be water-jet cooled immediately to prevent SRX at austenite GB and ensuring complete transformation to ferrite avoiding grain growth after coiling. Confirmation on old mills and successful product led to the design of more flexible mills for wider range of compositions and products. A significant one was auto bumpers that reduced crash damage. More crack-resisting compositions were developed for strip welding into line pipe for arctic oil transport. Lower metal consumption and easier fabrication has resulted in more sustainable welded bridging.

Jan 1, 2015

By R. K. Mishra, A. Kula, X. Jia, M. Niewczas

The mechanical properties of Mg-Gd and Mg-Y solid solutions have been studied under uniaxial tension and compression between 4K and 298K. The results reveal that Mg-Gd alloys exhibit higher strength and ductility under tension and compression attributed to the more effective solid solution strengthening effect and grain boundary strengthening. Profuse twinning has been observed under compression, resulting in a material texture with strong dominance of basal component parallel to compression axis. Under tension, twining is less active and the texture evolution is affected mostly by slip. The alloys exhibit pronounced yield stress asymmetry and significantly different work-hardening behaviour under tension and compression. Increasing of Gd and/or Y concentration leads to the reduction of the tension-compression asymmetry due to the weakening of the recrystallization texture and more balanced twinning and slip activity during plastic deformation. The results suggest that under compression of Mg-Y alloys slip is more active than twinning in comparison to Mg-Gd alloys.

Jan 1, 2015

By J. C. White

"During the early development of the Mattabi Mine in 1970, discussions with the Ontario Government revealed their policy of prohibiting, as much as possible, the development of new, isolated, single-industry townsites. Subsequently, Mattabi located its first housing in the Township of Ignace, which is situated 50 miles from the site of the mine and plant. Over 200 employees now commute 100 miles daily to and from work.This paper describes the experience gained and discusses the advantages and disadvantages of a remote townsite."

Jan 1, 1976

By A. Mitrašinovic, A. Wolf

"The aim of this investigation was to determine the most suitable additive for recovering metals from converter slags generated during Ni extraction. Fluxes analyzed were silica and lime and reductants included pig iron, ferrosilicon and copper-silicon compound. Slag was settled at 1300°C for one hour to simulate the smelting environment. The newly formed matte and slag were characterized by chemical composition and morphology. Microstructural studies showed that slag formed after adding reductants consisted of primarily fayalite, with traces of magnetite. Entrained matte was present in the slag mostly as prills of Ni3S2-FeS matrix and a Cu2S-FeS secondary phase below 10µm in diameter. Kinetic parameters of matte formation, valuable metal recovery rates and partition coefficients were deduced. Silica additions generated higher partition coefficients for copper and nickel than the addition of lime. Additives used as reducing agents had higher valuable metal recovery rates and partition coefficients. Silica additions favoured the formation a higher grade matte while lime additions will hinder metal recovery. Pig iron, ferrosilicon and Cu30Si were the most effective reductants for valuable metals recovery. Cu10Si and coke additions had little to no effect on valuable metals recovery."

Jan 1, 2015

By J. J. Jonas, G. R. Stewart, N. Pokutylowicz, S. Yue, R. Varano, A. Elwazri

Differing thermal histories in and around a weld can lead to differences in grain size, phase composition and morphology of precipitates; mechanical properties will vary accordingly. Hardness testing gives limited information and the machining and testing of tensile and/or impact specimens that would reveal these variations (which may occur over very small distances) is not practical. Therefore, in this investigation, shear punch testing was applied to measure the variation in the room temperature mechanical properties of a welded pipeline steel.

Jan 1, 2005

By Loui Geoffroy, Philippe Gaultier, Martin Piotte, Claude Coache, André Drouin

"Automatic driving at high speed of an underground truck was tested at Brunswick mine in September 1995. Modifications to the truck included: a remote interface to control actuators, front and back video cameras to follow a roof mounted optical guide and proportional hydraulic controls on the steering.The mathematical model of the hydraulic system was adjusted using least square regression. The steering data, used in calculating the regression parameters, were acquired from the moving truck. The automatic steering control used three measured variables: lateral deviation, angular deviation and steering angle. Lateral deviations are obtained using the cameras, which are in continuous view of the guide, while steering angles are acquired from an extensiometer placed at the articulation point of the vehicle. Gain scheduling was used to compensate for vehicle speed and available hydraulic flow. Non-linear characteristics of the modeled hydraulic system were offset using open loop compensation.Speeds up to 23 km/h in forward direction and 13 km/h in reverse were achieved deviaduring continuous testing along one of the mine’s production drifts. Proportional steering was essential in achieving high speeds, as it enabled more precise positioning of the vehicle’s steering direction while reducing the abuses on cylinder and cylinder pins via diminished oscillations about the optical guide at high speeds."

Jan 1, 1997

By David M. Knowles, R. Gordon Gastil

"The Precambrian sedimentary series of the Labrador geosyncline, including iron formation, extends into southwestern Labrador and adjacent Quebec. The iron formation consisted of primary oxide, silicate, and carbonate facies which were deposited simultaneously in an irregular basin in response to migratory environmental conditions. The iron formation isochemically recrystallized to coarse-grained quartz-iron oxide, iron silicate, and quartz-iron carbon-ate rocks during prolonged regional metamorphism. The rocks are deformed on two deformation axes intersecting at large angles, and are characterized by isoclinal to recumbent folds. Parts of the formation have been profoundly affected by a post-metamorphic leaching and oxidizing environment."

Jan 1, 1959

By T. G. Ewart

INTRODUCTION FOR THE purpose of this paper, western bituminous coal is defined as steam coal produced in Alberta and southeastern British Columbia for sale primarily to railways and industries. Before examining present and future markets of this industry, it is proper to review briefly financial and operating conditions within the industry. The report of the Royal Commission on Coal, 1946, supplies financial data from which some conclusions may be drawn. In 1944, the industry as defined above had share capital of $24,886,696. In the fifteen years 1930 to 1944, inclusive, the industry produced: 44,364,211 tons of coal. The profit on this tonnage amounted to $4,678,382.58, which represented 10.6 cents per ton of production. Miscellaneous earnings increased the amount available for dividends to shareholders to a total of $8,487,952.41, which is equal to, 19.1 cents per ton of production. Dividends actually paid in this fifteen-year period amounted to $12,332,040.64, which represented an annual average rate of 3.40 per cent on share capital. It is worthy of note that, in 1944, the net current position of the industry, including investments, was $8,753,874.51. The writer believes that the financial position of the industry with respect to capital, current financial position, and net earnings, has not significantly changed from the fifteen-year period out-lined above. The figures quoted indicate the following situation: (1) The western bituminous coal industry is adequately financed. (2) The industry has followed a conservative dividend policy and has accrued funds for contingencies. (3) The industry has sold its production at very reasonable prices as evidenced by its moderate earnings per ton of production.

Jan 1, 1951

By N. B. Brown

ABSTRACT The effect of a low4emperature stress relief at 232.2°C. (450°?F.) on the fatigue properties of shot-peened SAE. 1080 steel has been investigated. Specimens of the steel were first annealed. One half of the steel bars were then normalized and the other half were water-quenched and drawn. Specimens of the steel with each heat treatment were tested in tensile, notched bar impact, and fatigue. The fatigue specimens were test in air and water in R. R. Moore high-speed rotating bending machines in the following conditions: un-peened, peened, and peened-and stress-relieved at 232.2°C. ( 450°F.) The 'endurance life' and fatigue properties of specimens given a stress relief heat treatment after shot peening were superior to those of specimens given a smooth machine finish or shot peened. INTRODUCTION THIS investigation was initiated to obtain preliminary information on the effect on the fatigue resistance of shot peening the machined surface of a high-carbon steel similar in composition to that used in hollow drill steel. The data obtained in this investigation could be applied in analysing the application of shot peening hollow drill steel shanks. It is well known that the 'endurance life' and fatigue limits of steel are greatly ?improved by shot peening. References to this in the literature are numerous.

Jan 1, 1951

By B. J. Keating

"AT PRESENT, it is not certain that any of the sulphide de in the Province of Nova Scotia attain the lower grade limit of 60 per cent sulphides over the minimum area of 1,000 square feet suggested as cut-off specifications for inclusion in this Symposium. However, several of them do include massive sections of substantial size and others represent concentrations of sulphide material that are well above average. It is felt, therefore, that a tentative classification of the deposits and presentation of their geological settings are justified and may help round out the genetic aspects of this study. Accordingly, data considered to be the most pertinent are assembled here in the event that some may fit into larger-scale patterns of mineralization that may take shape as a result of this investigation.The three principal massive sulphide deposits in Nova Scotia are the Stirling, the Smithfield, and the Walton. The locations of these are shown on the accompanying key-map (Figure 1).Three other deposits, the locations of which are also indicated on the map, are the Meat Cove, Rocky Brook, and Gays River de¬posits. Although these fall far short of the minimum dimensions and grade specifications referred to above they are singled out because they have received more than passing attention and are illustrative of the mineralization types to which they belong."

Jan 1, 1960

The JKRBT (JK Rotary Breakage Tester) is a newly developed impact breakage testing device for rapid ore breakage characterisation, and has recently been commercialised after a three year comprehensive validation study, involving five major mining companies and six industrialised JKRBT units deployed worldwide. Comparisons of breakage mechanisms and characterisation data between the JKRBT and the Drop Weight Tester (DWT) indicate that, despite the differences in the breakage modes, the JKRBT can provide statistically similar A*b parameters, by using a data reduction procedure which takes into account the difference in the number of contact points, strain rate and potential for secondary breakage. Feedback from the validation sponsors has indicated higher productivity and better repeatability of the JKRBT compared with the DWT. This better precision, combined with the JKRBT?s wider particle size capability and wider specific energy range, provide a more powerful tool, ideally suited to rapid mapping of ore hardness in geometallurgical and comminution applications.

Jan 1, 2012