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By D. G. MacBeth

Most belt scales on the market are factory calibrated to minimum accuracy figures of 0.1% - 0.2% at several load points. However, if the same belt scale is not properly installed and maintained on the customers conveyor then the scale will not measure up to the claims of the manufacturer or to the requirements of the operator.

Jan 1, 1975

By S. Vaidya, R. C. McKellar, N. K. Sinha

Nominally [001]-oriented nickel-base single crystal (SX) superalloy CMSX-10 was investigated at 900°C under constant load, equivalent to an initial stress of 700 MPa, for creep strains from 7% to fracture strain (18.2%). The cross-sectional dimensions of initially uniform cylindrical specimens were measured along their entire length after the tests. The cross-section changed from circular to near elliptical shape. The anisotropic deformation, measured in terms of eccentricity, increased with the increasing strain level, but for a given strain level, it remained constant along the entire length of the initially uniform gauge section. The results are discussed in terms of diameter, eccentricity, area, local stress and microstructural observations. The most striking observation was the fact that all the specimens displayed a yoke-like shape, or the reduction of cross sectional area, at two locations within the originally uniform gauge section. Such observations have not been reported in the literature for single crystal superalloys.

Jan 1, 2006

By Jamie King

This paper describes the use of dynamic scheduling and discrete event control to provide coordinated control of multiple automated vehicles. In the past decade there have been significant advances in the field of robotics for underground mining. As this trend progresses toward a realization of a completely automated underground mine the need for a central control system, capable of providing coordination for multiple vehicles in a semistructured environment, becomes more evident. In the past year general research into multi-robot coordination has been applied to the underground mining scenario and demonstrated in a scaled model underground mine in a laboratory setting. This system shows significant potential to be adopted into a full-scale implementation for mine wide automation.

May 1, 2001

By C. O. Aksoy, H. Kose, K. Ozfirat, T. Malli, A. Gonen, S. Gurgen

In selecting mobile mining equipment, factors including availability, useful economic life, maintenance and operating costs, and spare parts availability are considered. Given these factors, trucks and shovels with different capacities are selected. Optimizing equipment for pit and hillside quarry cases, where 8% and 10% ramps are commonly in use, were examined; the effect of other mining activities such as drilling and blasting on unit cost were considered. In principle, 20 m to 25 m high benches should be economical for downhill haulage, and 7 m to 10 m low benches economical for uphill haulage. However, practice of both mining styles favours 10 m to 15 m bench heights. Hence, the analysis here was carried out with the field experience bench height range. In the study, a truck-shovel optimization was based on the movement of 5 to 20 million cubic metres (in 2.5 million cubic metre increments) of overburden stripping at the Eynez open pit mine in the Soma region of Turkey. The outcome showed that low-capacity shovels were unfavourable due to high production expectations. High-capacity shovels were also unfavourable due to health and safety issues causing high instances of impact vibration on trucks during the loading cycle and a decrease in foreseeable unit lifetimes. The number of shovel passes required to load a truck ranged from three to six. Trucks with high-capacity bodies were deemed uneconomical due to high investment and operating costs.

Jan 1, 2005

By Stavros A. Argyropoulos, Radhakrishna Valiveti, Bernard Closset

"The use of microprocessors in metallurgy is currently increasing at a very fast rate. A large number of companies are offering systems ""off the shelf"" which are aimed at the data acquisition and process control market. There are two main drawbacks to these systems: first, they are usually quite expensive, and second, they are not completely compatible with the target metallurgical application. An alternative is to develop a microcomputer-based system "" in lab "".A dedicated microcomputer system has proved to be very useful in many metallurgical research applications(1,2)). However, in this system the analog input signals had to be transferred over long distances , and significant noise was introduced despite the use of shielded cables. In order to overcome this problem a network of low pass-filter s was designed and built. The usage of the abovementioned system brought the need to digitize the analog signals in-situ and transfer the digital signals, which are much less susceptible to noise over very long distances. This distinctly different design philosophy has become a reality with the evolution of microprocessor technology over the last few years. This design philosophy is utilized in this development."

Jan 1, 1984

By Mauro Chiesa

An Overview on the Presentation A.The Markets ?Mining Industry ?Capital Markets ?A Six-Cell Matrix of Strategic Options B.De-Risking The Mining Assets ?The Value-Added ?The Assets: Current and in Development ?The Feasibility Study C.(Questions, and answers) Post-Crunch: Some Maxims ?Three Metal Market Models No Longer Prevail ?New models are uncharted: ?be prepared?(ref: Lord B-Powell). ?Capital markets are pricey & uncertain: be your own financier first ?focus on value and on cash-flow (not oz, lbs, tonnes, LOMs, etc) ?Know your banker/financier(and it should know mining) ?In the past, it was ?know your borrower? ?It?s a buyer?s market that wants the ?right deal?: so cast a big net: ?Data must be current, concise and consistent ?3rdparty validation of feasibility work is now a ?passport? ?The risk matrix, with de-risking, is as important as the ?math?

May 1, 2011

By John E. Udd

The stability of a rock mass is influenced by the presence of discontinuities. In assessing stability, it is required that one should know the frictional and cohesive properties of these contained weaknesses. In the study performed by the authors, a number of samples of diamond drill core containing open discontinuities were tested in shear. The results obtained were compared with values which resulted from back analyses of instabilities in the field.

Jan 1, 1979

By Daniel Hodouin, Mélanie Proulx, Claude Bazin

"Collector and frother are commonly used to induce the floatability of valuable minerals in flotation plants. These reagents are usually distributed down a flotation bank or sometimes added in a single location at the top of the bank. A review of the literature and some experimental results obtained from laboratory and full scale trials indicate that the way flotation reagents are distributed down a flotation bank may influence the flotation response of coarse particles. The paper summarizes these observations which show that the distribution of reagents is a potential tuning variable for process optimization.IntroductionFlotation is in many cases the only way to concentrate sulphide and some oxide minerals. Flotation is a concentration process that uses particle surface composition to induce the selectivity by mean of hydrophobic reagents. The influence of particle size on flotation was firstly analyzed in the 50's1·2 and intensively investigated in the 70's, early 80's and 90's3-18. Most of the observed results show the existence of an optimum flotation size range9 whose recovery is not significantly influenced by a reduction of collector dosage""18. This result brought the idea of using a small portion of the total collector dosage at the top of a rougher bank and to distribute the remaining through the end of the bank to ensure sufficient collection of the coarse particles that need more hydrophobic coverage to attach to air bubbles and be lifted to the surface.This paper discusses the idea of using the distribution of reagents down a flotation bank to tune the operation of the process. Unlike the literature on the effect of reagents (collectors, frother...) dosage that is dense, little attention has been put on the distribution of reagents in a flotation bank. Although research on this subject has not been pushed very far, some operators have recognized the potential of a strategic addition of reagents down a flotation bank19. Except for a few exceptions, the proportions of the reagents to be distributed down a flotation bank are decided according to operator's experience instead of process analysis in relationships with particle size. This paper recalls observations made by different researchers that lead to the idea of using the distribution of reagents as a tuning variable for the flotation process. The paper does not present a detailed analysis or optimization scheme for tuning the distribution of reagents, but analyzes some plant and laboratory results with a view toward the development of a testing methodology and ultimately a validation or rejection of the idea."

Jan 1, 1998

By Raj Thamburaj, Li. Ping, Prakash C. Patnaik

"An effective prognosis system for aircraft engines may involve the application of a wide range of technologies and methodologies, which may include: - On-line, real-time and in-situ non-destructive inspection/detection/sensoring - Aircraft/engine instrumentation - Airborne data recording system - Advanced signal filtration - Data compression technologies - On-line engine health monitoring technologies - On-line engine component life usage monitoring technologies - Mission severity analysis algorithm based on life prediction and damage tolerance analysis models - Life assessment methodologies - Optimized repair/overhaul/maintenance planning - Optimization of mission assignment and homogeneous life usage - Web-enabled information delivery and sharing system - Decision making logistics This paper will demonstrate some efforts that Orenda has accomplished over the last decade in collaboration with the Institute for Aerospace Research of National Research Council Canada and the Department of National Defense. The presentation will focus on the following projects:"

Jan 1, 2004

By K. .. Sadayappan

The increasing cost of selenium made the conventional low lead alloys such as EnviroBrasses not economically viable. Efforts were made to develop newer alloys without selenium for plumbing applications. Recently a new copper alloy, C89836, was introduced. This paper discusses the properties of the new alloy including mechanical properties at ambient and elevated temperatures as well as corrosion behaviour.

Jan 1, 2007

By S. D. Botts, F. Cantuarias

"The Antamina project, owned by BHP Billiton Plc, Mitsubishi Corporation, Noranda Inc., and Teck Cominco Ltd., is a $2.3 billion copper/ zinc project, located in the Ancash Department of Peru. The project consists of an open pit mine, a 70 000 ton per day concentrator, a 302 km long concentrate pipeline, port facilities, a new access road, power line, and town site. The project is designed to produce up to 1.5 Mtpy of copper and zinc concentrates over a 23 year project life, and will be the third largest producer of zinc and the seventh largest producer of copper in the world.This mega project is the largest mining investment in the country and, during its construction stage, was the most important construction project worldwide. On May 28, 2001, Antamina commenced testing operations and four months later, it reached commercial production. Antamina was officially inaugurated on November 14, 2001 by Peruvian president Alejandro Toledo.The construction stage of the project generated 8000 direct jobs, with a peak of 10 000 employees, and 30 000 indirect jobs. The permanent workforce consists of approximately 1650 employees, the vast majority of which are Peruvian Nationals, around 30% of whom came from the region where the deposit is located. Approximately 5600 indirect jobs were generated from the project. Independent sources state that Antamina increased the Peruvian mining exports by 30% (mining exports constitute 50% of Peru’s total exports) and Peruvian GDP by 1% in its first year of full operation in 2002.Since winning the privatization bid for the project in 1996, the company has implemented an approach to community development and environmental protection based on sustainable development principals. Throughout the development of the project, a number of initiatives have been undertaken to ensure full involvement of the local populations in community development activities and the company’s environmental program.Due to its size, difficult logistics, cultural considerations and financial aspects, the project has faced a number of unique challenges in the area of environmental protection and management of community interaction. Antamina has been innovative in its approach to these issues and, as a result, has set new standards in Peru for environmental and community management and sustainable development."

Jan 1, 2003

By Junior Santos

Kinross Paracatu started the operation of the new gold processing plant in the end of 2008, being composed by one SAG mill and two ball mills. During the first year of operation the plant had several problems related to stability and throughput capacity, mainly due to low grinding efficiency of the ball mills. In this period many actions were taken to maximize the throughput rate. Among the actions are reducing the size of balls in the mills, increasing the ball charge in the SAG mill, changing cyclone configuration and return of circulating load to SAG mill. With better stability of the circuit, the second stage of improvements has begun with the objective of increasing throughput rate and also reducing operation costs. Among the actions are the optimization of ball charge in the mills and a better operational control of cyclone parts. After two years of operation was obtained a significant increase in plant capacity, but still requires the addition of a third ball mill in order to maximize the use of SAG mill, which has spare capacity.

Jan 1, 2012

By Isabel F. Barton, Matthew J. Gabriel, Mark D. Barton

Process control, mine-to-mill optimization, and other mining operations depend on having robust, comprehensive mineralogical and chemical characterization. However, current characterization methods rely primarily on analyzing samples from trenches, channels, blast holes, and drill holes and interpolating between them, and are not always sensitive to some minerals (such as clays) that cause major problems for mining and mineral processing. Continuous characterization is possible with techniques such as hyperspectral remote sensing, which measures reflectance or absorption of light in the visible to near infrared (VNIR) and short-wave infrared (SWIR) regions of the electromagnetic spectrum. Absorption and reflectance features are characteristic of different chemical bond types, so each spectrum corresponds to a different mineral or material. In remote sensing, each pixel in the scanned area has both a location and a spectrum. This makes hyperspectral remote sensing potentially useful for characterizing mine site materials. In this study, we tested a hyperspectral remote sensing system as a method of characterizing the mineralogy and material types at mine and metallurgical sites. Our test site was a small open-pit copper mine and leach operation in the southwestern U.S. We scanned mine highwalls, dump piles, leach pads, and nearby rock outcrops with drone- and tripod-mounted VNIR-SWIR spectrometers. We collected ground-truth data through geologic mapping, sampling, and spot analyses with a portable short-wave SWIR instrument. The results show that the hyperspectral remote sensing system that we tested is capable of distinguishing the types and distribution of spectrally active minerals and other materials in diverse mining settings, including showing wet and dry areas of leach pads; clay and carbonate type and distribution on mine highwalls, leach pads, dumps, and rock outcrops; plant type and distribution; fault zones, bedding planes, and other geological features; and qualitative spectral matches between dump piles and areas of the mine highwalls. Hyperspectral sensing proved particularly sensitive to the presence and type of clay and carbonate minerals, which cause geotechnical and metallurgical problems such as highwall failure, gangue acid consumption, and flotation sliming. Examples will be presented and discussed at the conference. Areas of continuing research include automating and streamlining the data reduction process, integrating hyperspectral data with block modeling and mine planning software, and testing the results of hyperspectral sensing in different geological environments.

Jan 1, 2019

By Stephen Hammond

?Our own prejudices form the greatest barrier to creating an inclusive working environment.? Have you witnessed? Racism or Negative Comments about an Aboriginal Person? ?You are free to compete with all the others?, and still justly believe that you have been completely fair.? Lyndon B. Johnson

May 1, 2008

By K. E. Waters, N. Brodusch, R. Gauvin, H. Demers

"Rare earth elements are becoming increasingly in demand, due to their prevalence in both renewable energy devices and high-end electronics. The characterization of the composition, morphology and volume fraction of the various phases that have valuable rare earths in the ores are needed to find the optimal industrial process to extract the ores containing the rare earths. Rare earth-bearing minerals contain many elements with the M-and L-lines overlap, requiring a high degree of resolution, pushing the boundaries of scanning electron microscopy quantitative analysis. Enhanced microscopy at a high spatial resolution with improved x-ray quantitative analysis enables the accurate determination of the distribution of the desired rare earths in various mineral phases. INTRODUCTIONRare earth elements are becoming increasingly in demand, due to their prevalence in both renewable energy devices and high-end electronics. From batteries (lanthanum and cerium), to magnets (dysprosium and neodymium) and lighting (yttrium), the rare earth elements are crucial to the advancement of technology, and to energy saving devices (Crow, 2011). The goal of this project is to characterize the composition, morphology and volume fraction of the various phases that have valuable rare earths in the ores in order to estimate the economical VALUES (of the ores and to find the optimal industrial process to extract the ores containing the rare earths. High spatial resolution imaging and x-ray microanalysis are needed to reach this goal. In this work, the results obtained with a cold-field-emission scanning electron microscope (FE-SEM) and a silicon drift detector (SDD) energy dispersive spectrometry (EDS) detector at low accelerating voltage are compared to experimental conditions typically used with electron probe microanalysis (EPMA) instrument.With this improvement, a detailed scientific analysis of the composition of these, and other, ores will become possible with a SEM/EDS system. This will help to better understand how such ores were formed, hence assisting in finding them, and to better understand how to process them in preparation for high end industrial applications, namely through mineral processing."

Jan 1, 2012

By James L. Parks, David M. Kjos

"Significant increases in mill liner life and plant availability can be achieved by following guidelines that have evolved from over twenty years of practical experience with autogenous grinding (A0) and semi-autogenous grinding (SA0) mills. A0 and SA0 mill liner functions, performance criteria, designs, wear-resistant materials and maintenance procedures are reviewed. Operating practices that can lead to accelerated wear and breakage are discussed.IntroductionEfforts to improve the performance of liners for autogenous grinding (AG) and semi-autogenous grinding (SAG) mills began as soon as the modern, large-diameter versions of these comminution machines were first intalled in commercial plants twenty years ago . While concentrators with conventional circuits were typically running at 95010 or better mill availability, many of the new autogenous and semi-autogenous circuits were struggling to achieve 80% availability. Liner maintenance, which involves not only material and labour costs but also loss of production, was quickly identified as one of the major reasons for downtime.Today, liner designs and materials have evolved to the point where virtually maintenance-free liner life of two to three years is possible in autogenous mills and one year in the more severe operating conditions encountered in semi-autogenous mills. Of concern, however, is that hard-won lessons from the past sometimes seem to be forgotten or ignored during the design of new mills and the operation of existing mills. As liner suppliers, we are often confronted with performance problems that could have been avoided by applying well-publicized guidelines for liner design and materials selection.This paper provides an overview of AG and SAG mill liner functions, criteria for evaluating performance, designs, wear-resistant materials and maintenance procedures. Also, operating conditions that can lead to accelerated wear and liner breakage are discussed in detail."

Jan 1, 1990

By J. Huh

Recently, there is growing trend to build the high-rise and install curtain walls. Following this trend, we developed robot for building wall cleaning work, which moves along Built-in guide rail of building. Because it moves attached at building wall for cleaning work, it can be seriously affected by potential threats, like earthquake, strong wind, malfunction, and construction error of built-in guide rail. In order to cope with those threats actively, this paper presents the Fail-Safety system. The building wall cleaning robot consists of two moving system: The Horizontal Moving System which mainly do maintenance work, and The Vertical Climbing System which transport the horizontal moving system floor by floor. We apply the Fail-Safety system to these systems. The Fail-Safety system consists of sensors to detect external situation, and, with information of sensors, give instruction for what to do. This robot system is installed with four kinds of sensors: shock sensor, infrared ray sensor, laser sensor, magnetic sensor. First, shock sensor detects external shock during cleaning work. When shock sensor detects big shock, the robot returns to starting point to inspect how damaged it is. Second, infrared ray sensor detects damage of built-in guide rail. It is to prevent destruction of robot caused by moving along damaged rail. Third, laser sensor gives notice about where obstacle is. It is for robot to avoid crash with obstacle and decrease damage. Fourth, magnetic sensor detects magnetic points, which are installed in rail at regular intervals, and helps robot to find its position, based on location of magnetic points detected. If robot is damaged by external shock and its encoder, which gives information of location to it, is not working, magnetic sensor will give information of robot?s location to robot. And then, robot regulates its velocity depending on position of it, and safely returns to starting point. The Fail-Safety system in this paper is for building wall cleaning robot to sense external threats, and prevent getting worse. Applied to this active protection system, making safe environment of maintenance work is possible for robot system.

Aug 1, 2013

By H. Mindivan

In the present study, the feasibility of recycling AA6061 Al alloy chips by a combination of ciyomilling, cold compaction and hot extrusion processes was investigated. Furthermore, the effect of Al powder addition to the recycled Al alloys chips on the mechanical properties was investigated. The characterization of recycled Al alloys was made by structural examination and mechanical tests (hardness, compression and dry sliding wear tests). The results indicated that by increasing wt. % of Al powder added to the recycled Al alloy chips the studied properties (the density, hardness, compressive strength and wear resistance) increased due to reduction of porosity in the recycled Al alloys.

Jan 1, 2011

By Gaétan Bourdages

A clarification technology used by municipalities to produce high-quality drinking water, polish sewage treatment plant effluent and handle combined sewer overflows has recently found new applications in the mines and iron and steel industry. This patented process, known as ACTIFLO®, utilizes microsand in a ballasted flocculation process to enhance the settling characteristics of suspended solids, increasing the efficiency sufficiently to achieve a clarifier footprint that is smaller than the one of a conventional clarifier. ACTIFLO® rise rates vary from 40 to 170 m/h with a total system hydraulic retention time of about 10 minutes. The result is a clarification system so compact that a full-scale system can operate as a trailer-mounted unit for temporary applications or as a permanent installation in facilities with space limitations. This paper explains the process and presents case studies in which this innovative technology was used at mines and steelmaking facilities to meet compliance requirements.

Feb 1, 2008

By P. B. Demarsh

"Location: - On highway 59, 17 miles east of Val d 10r near junction of Montreal highway in Northwestern Quebec.Life; - Started production 1952, ceased 1965.Ore: - Pyrite, chalcopyrite and small amounts of free gold and goldsilver tellurides in narrow quartz-carbonate-tourmaline veins in granodiorite. Specific gravity 2, 70.Capacity: - 700 tons daily Bevcon ore supply, l 000 tons daily when custom ore available.Assay: - Heads 0 .140 oz. per ton; tails 0. 009 per ton; extraction 92.5%.Grind: - 75% minus 200 mesh at 700 tons; 68% minus 200 mesh at 1000 tons. Detention time 28 hours and 21 hours respectively.Treatment: - Cyanidation process.Reagents: - Per ton. Aero Cyanide (NaCn) 0, 50; crushed unslaked lime 1. 75; zinc 0. 03; litharge 0. 10; steel consumption 2. 25.Water: - Pumped from land-lock spring fed lake l 1/2 miles distant.Cost: - Per ton. Crushing 0. 13; grinding 0 .32; filtration 0. 07; cyanidation 0.14; miscellaneous 0.29; total 0.95.Power: - Hydro-electric, 25 cycle, 12, 000 volts reduced to 550 volts.Labour: - Predominantly French Canadian, nucleus English Canadians.Tailings: - Impounded low lying pond.Personnel: - 15 including supervision.Flow sheet: - Canadian Mining Manual l 9 5 6 .Building: - Wood truss construction: 3/ 4 in. siding, ten test and 1/ 4 in. transite outside. Corrugated galvanized iron roof. Ground level foundations. Internal self induced heating. Wood stave tank equipment."

Jan 1, 1966