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By W. F. Harkness, D. Hodgkinson

"A non-destructive testing program was established at Crows Nest Resources (C.N.R.), Line Creek mining operation following an in-service fatigue failure of a front wheel spindle on a large haulage truck.This failure identified a definite need for improvements in the ultrasonic techniques used during the mandatory spindle integrity examinations. Initial investigations using common mining industry ultrasonic examination techniques showed that the smallest detectable cracks were 75 mm in length for the spindle types in service at the C.N.R. site. The Initial findings indicated that inadequate inspection technique design was the cause of the poor performance. To improve inspection reliability it was identified that improved ultrasonic techniques were required. Results using designed ultrasonic techniques were encouraging, with the detection of simulated and natural cracks 12 mm long achieved. The cost benefits associated with the extended spindle life, following the removal of these small fatigue cracks, far exceeded those of the expertise and effort necessary to implement and conduct the N.D.T. program.Introduction During 50 years of evolution, non-destructive testing (N.D. T.) has progressed from a laboratory curiosity to a well accepted and invaluable tool used in the assessment of material integrity. Unlike destructive testing, N.D.T. does not deform or render the material useless. Non-destructive tests may involve many applications, from the determination of a corrosion prevention coating thickness to the examination of a raw material for internal and external deformities.Within the mining sector, highly-stressed components will normally have been subjected to some form of non-destructive test during their manufacturing cycle. These tests are used to ensure the component does not contain material flaws whichmay be detrimental to its service performance.While the component may have assured quality when produced, deterioration by fatigue may occur during an aggressive service life. Large dynamically-loaded components such as haulage truck front wheel spindles are , in particular, prone to this service related problem."

Jan 1, 1987

By A. Iizuka

This study was aimed at separating and recovering arsenic, antimony, and tin from refining byproducts generated in a nonferrous smelter. The target byproduct was a silicate slag containing the above elements. The silicate structure of the slag was destroyed by alkali roasting, which then enabled leaching of arsenic, antimony and tin in solution effectively. Arsenic was selectively leached out by hot water after alkali roasting of the slag, while remained antimony and tin in the residue were leached out by a hot hydrochloric acid solution. However, when the solid-liquid ratio in the leaching solution was increased, hydrous gelatinous silica (gel-like silica) was formed during the hydrochloric acid treatment and filtration became difficult. Therefore, high temperature and high pressure leaching was attempted to improve the filterability of the silica leaching residue. In the high temperature and high pressure treatment, the hydrous gel-like silica was transformed into easily filterable aggregated silica, and thus, filtration became easy. By investigating the neutralization and sulfurization treatment for the obtained hydrochloric acid leachate (second leachate), it was possible to separate antimony and tin. INTRODUCTION This study aims to separate arsenic and recover valuable metals such as antimony and tin from refining byproducts generated in a nonferrous smelter. The target smelting byproduct is antimony-containing slag in this study. In many cases, alkali roasting was adopted as pretreatment for extraction and recovering valuable metals from smelting residues and wastes (Rao, 2006). For antimony-containing slag in this study, one effective method for separating arsenic is to convert arsenic to sodium arsenate (Na3AsO4) by roasting with a sodium compound and then to remove arsenic by hot water leaching. In addition, by alkali roasting, the silicate structure of the slag is destroyed, and effectively alkalizing tin and antimony is accomplished. Then, precipitating and recovering tin and antimony leached into the acid solution are considered possible by sulfurization and neutralization treatments. In this research, we conducted basic studies on the following. 1) Destruction of silicate structure in slag by alkali roasting and leachability of arsenic. 2) Conversion of hydrous gelatinous silica to aggregated silica by hydrochloric acid treatment of residues after arsenic leaching under high temperature and high pressure, as well as leachability of antimony and tin. 3) Separation and recovery of antimony and tin by sulfurization and neutralization treatments of hydrochloric acid leachate. These topics of investigation can support to consider the separation and recovery process of arsenic, antimony, and tin from antimony containing slag.

Jan 1, 2019

"This paper describes an alternative method of vehicle control which uses a micro-processor to control the field current and armature voltage concurrently. The field tests carried out and the conclusions drawn from the basis of the paper.IntroductionIt is generally accepted that the main obstacle to a greater use of electric vehicles is the relatively poor range and performance when compared to alternatives such as diesel and petrol-engine vehicles. Much effort has been applied to the problem of increasing the energy storage density of batteries and considerable improvements are now being reported.Improvements in the efficient use of the stored energy, although unlikely to achieve the necessary increase in range and performance for a widespread acceptance of electric vehicles, can nevertheless make a useful contribution. Because the improvement in efficiency is achieved by a reduction in losses, it follows that the temperature rise in drive-train components is reduced. These advantages, coupled with the increasing cost of energy, make improvements in the efficient use of the stored energy desirable, if not absolutely necessary. To achieve this with the large and rapidly varying loads encountered during the operational use of a vehicle will require a more flexible system of control than that provided by the current limit. This paper describes an alternative method of control which uses a micro-processor to control the field current and armature voltage concurrently.The value of these parameters is selected to supply the power demand at the motor shaft, with the minimum losses in electrical transmission, thus increasing the efficiency with which the stored energy is used."

Jan 1, 1982

By Dillon. Patricia

Business Growth ?Coal ?Targeting 30 million tonnes by 2013 compared to 19 million tonnes produced in 2009 ?Expanding Energy Business unit (Oil Sands) ?Copper -Strong growth potential for existing operations and development projects ?New gold strategy recently launched ?New markets for zinc Need to retain existing and attract new employees to support growth Engaged Employee ?Has a positive attitude towards the organization and its values ?Is a person who is fully involved in, and enthusiastic about, his or her work Engaged employees are more likely to stay with the organization.

May 1, 2010

By C. H. Bertoni

"The Superior Province of the Canadian Shield is the largest gold producing area within Archean greenstone rocks in the world, with total production of over 140 million ounces of gold. One hundred and fifty-five mines have individually produced more than 8,000 ounces, although only a relatively limited number of deposits (33) produced more than one million ounces of gold. The output from these 33 deposits accounts, however, for 85% of total gold production. The majority of grades (68%) ranges between 0.10 and 0.30 ounce per ton, and there is no linear relationship between grade and tonnage.Development of new gold mines reflects the history of gold prices. However, the response to the latest increase in gold prices was not as marked. It is concluded that gold deposits are becoming increasingly more difficult to find and new exploration techniques are urgently required.IntroductionWith most of its production coming out of the Superior Province, the Canadian Shield is the largest producer of gold from Archean greenstone rock s in the world. In total gold production, the Superior Province is surpassed only by the paleo-placers of Witwatersrand and the placers of the USSR (Anhaeusser, 1976). There has been no attempt so far to compile the historical production of the Province as a whole in a single document. The aim of this work is to fill this gap, not only for the convenience of having a complete list of gold producers, but, more importantly, as a basis on which to study the tonnage and grade characteristics of these deposits."

Jan 1, 1983

By D. A. Beck

The load-deformation response of discontinuous rock under static and dynamic loading conditions has been simulated using Explicit Finite Element models. The intent of the analysis was to investigate the effects of specimen size and confining stress on strength, dilation and comminution. The simulations allow the development of homogenised constitutive material properties for discontinuous rock masses using laboratory scale measurements and representative Discrete Fracture Networks (DFNs). A procedure for this is presented which includes a comparison of measured seismic response in a mine to the Dissipated Plastic Energy (DPE) that is released in the simulated rock masses. The models also show how confinement and scale affect the stress-strain and DPE response of the simulated rock specimens, reproducing a number of known rock phenomena that are often poorly captured in geotechnical modelling. A case study is presented showing a satisfactory match between the model-derived, homogenised material properties and values achieved by calibration of a mine-scale model where many thousands of seismic, displacement and damage measurements were available.

May 1, 2009

By Naoki Takada, Dae-Sung Cheon, Minoru Sato, Masaji Kato, Manabu Takahashi, Weiren Lin

"The permeability and specific storage of rocks and sedimentary layers deep underground are critical parameters for issues related to the buried evaluation of natural gas and oil, CO2 aquifer storage, various kind of waste storage and so on.The Shirahama sandstone of the Wakayama prefecture, Kii peninsular in central Japan, consists mainly of quartz grains with no cracks and rock fragments that are aggregations of various kind of minerals. The quartz grains have an average size of about 150 micron. The pre-existing pore sizes were distributed dominantly at approximately 1 micron, and the total porosity was about 13%.During the hydrostatic compression test, we measured permeability of Shirahama sandstone by Transient Pulse test for three mutually perpendicular directions. Permeability of Shirahama sandstone remained fairly constant while increasing the effective confining pressure. Permeability anisotropy was observed slightly in the normal and two parallel directions to the bedding planes.We used micro focus X-ray CT with high resolution of 10 micron to visualize and measure the voids space information in Shirahama sandstone. Three-dimensional data were obtained in the intact and stressed sandstone simultaneously. Pore structures and grain boundaries were clearly distinguished. Pore closure and grain movement were clearly observed with increasing confining pressure. Micro focus X-ray CT is an effective tool to visualize and measure the geometrical information in rocks.Three-dimensional medial axis (3DMA) method was introduced to quantify the flow-relevant geometric properties of the voids structure in Shirahama sandstone using µfocus X-Ray CT data. The number of connecting path between two faces, tortuosity and the shortest path distribution within an arbitrary region of Shirahama sandstone specimen were analyzed. Geometrical information on the number of connecting path shows reasonable correlation between permeability anisotropy and mutually perpendicular directions normal and parallel to bedding planes. In addition, we introduced numerical simulation of fluid flow of pressurized Shirahama sandstone by LBM, to discuss the permeability change caused by pressurization on effective confining pressure. We obtained the detailed distributions of fluid pressure and fluid velocity in relatively narrow voids space more than 10 µm. It was confirmed that pressurization effect on permeability caused by the decrease of the connecting path and the shortest path between arbitrary faces, and then caused a complex condition on fluid pressure and fluid velocity."

Jan 1, 2015

By Lucas van Latum

A Model for Safety Swiss cheese metaphor of safety layers Image »Multiple layers with independent, often transient failure modes »For a loss to occur, all layers must fail independently and simultaneously ??Latent? failures are due to inherent system flaws ??Active? failures are due to unsafe acts

May 1, 2011

By X. -G. Chen, A. M. Nabawy

A novel manufacturing technique for Al-TiB2 nanocomposites has been developed, in which TiB2 nanoparticles were incorporated into liquid aluminum under mechanical stirring and in the presence of a K2ZrF6 flux-wetting agent. The microstructure of the Al-TiB2 nanocomposites was studied using scanning electron microscopy (SEM) and transmission electron microscopy (TEM). The microhardness test was conducted to investigate the strengthening effect of TiB2 on the aluminum matrix. The TiB2 nanoparticles were successfully incorporated and dispersed into the aluminum melt in the presence of the K2ZrF6 flux during mechanical stirring. In the as-cast microstructure, most nanoparticles segregated in the interdendritic regions as a result of particle redistribution during solidification. The addition of 2, 5 and 10 wt% TiB2 nanoparticles increased the composite hardness by 60, 90 and 150% respectively when compared to commercial purity aluminum, indicating that the TiB2 nanoparticles imposed a significant strengthening effect on the aluminum matrix. The role of K2ZrF6 flux agent on the incorporation of nanoparticles into aluminum melt was discussed.

Jan 1, 2014

By Paul Clayton

Case Study ? Site: BMA Saragi Coal Mine Queensland Australia ? Model: Marion 8050 ? YOM: Mid 1970s ? Boom: 97M ? Bucket: Original capacity of 100 Tonnes upgraded to 125 tonnes at time of filtration upgrade. ? Apps: Swing, Hoist & Drag Gearboxes ? Oil: Oil Castrol Alpha TT1200 Viscosity of 1208 cSt @ 40° C (104° F) 720ltr Oil Volume Trial and Installation Justifications ? To reduce gearbox overhauls. Typical schedule being 5 years. ? Bucket upgrade from 100 tonnes to 125 tonnes. Increased gearbox demand and stress. ? Increase of overhauls out to 10 years + ? Saving per Dragline estimated to be US$8-10M in downtime and maintenance if successful. ? In compliance with BHPBilliton Global Maintenance FLAC program ? Fuels, Lubricants, Air and Coolants ? Cost Justification ? Downtime: 4 days ? Lost production: $420,000 ? Cost of parts: $162,000 ? Labour and misc: $41,000 Gearbox failure cost $623,000

May 1, 2008

By Simon C. Dominy, Ian M. Platten, Garry F. Johansen, Alwyn E. Annels, Brian W. Cuffley

Abstract - Coarse gold-bearing veins are characterized by high grades that are localized and erratic. Effective sampling of coarse gold-bearing veins is difficult because of the low concentration and erratic nature of the gold particles. Diamond drilling is an effective measure of geological continuity, however, grade distribution can only be reliably obtained from underground development (including close-spaced sampling, bulk sampling, and trial mining). Comparison between surface and underground drilling, underground linear/panel and bulk sampling indicate that drilling and linear/ panel samples generally understate bulk sample grades. Bulk samples are likely to be the closest estimators of true grade. It is unlikely that anything above an Inferred Resource category can be estimated from surface drilling alone, and at best the grade will only be a global estimate. Underground development, in-fill drilling and bulk sampling/trial mining will be required to delineate Indicated and Measured Resources. Closely spaced development and bulk sampling is likely to be the only way to determine Reserves. The resource estimation process must driven by a clear geological model that should attempt to understand both geological and grade continuity. Traditionally, grade interpolation has been undertaken using classical methods, though more recently, computer-based block modelling techniques have been used with some success. Three case histories are presented, documenting the problems of estimating resources in coarse gold-bearing veins and the practical ways in which they were approached.

Jan 1, 2000

By G. Chi

Outline 1.Regional geologic setting 2.Host rocks and structures 3.Mineralization, alteration and paragenesis 4.Geochronology 5.Major and trace elements 6.Fluid inclusions 7.Carbon and oxygen isotopes 8.Conclusions

Apr 1, 2005

By Tim Mann

"Like other operating mine sites, Placer Dome Inc. - Campbell Mine has taken important steps over the last few years to address environmental issues.This paper will provide specific insights into the implementation of an environmental management system at Campbell. In particular, it will focus on how Campbell developed its plan of action; the lessons that have been learned; the over-all steps that are being taken to enhance environmental stewardship and effectively manage relationships with key stakeholders.IntroductionThe development of an Environmental Management System at Campbell Mine has been part of a general development in management practices which has taken place at the mine during 1990. This paper will discuss the components of the management system in the topic areas of: direction setting; environmental organization; issue assessment; emergency response plan; training ; monitoring/verification; reporting and data management; and relationship management.Although this paper focuses on environmental management systems, the development of this system has partly been a function of responses to other issues which have been addressed concurrently with environmental concerns. These other issues include development of operations management, human resources practices, and safety management practices at the mine. As the Environmental Management System developed, various stakeholders associated with local environmental concerns were identified. This group of stakeholders include the local community; municipal, provincial and federal governments; government agencies; Campbell employees; and the Placer Dome Inc. Corporation."

Jan 1, 1991

By F. T. Manns, G. Harper

"The Swayze gold mine is an Archean vein deposit in northern Ontario. The veins are superimposed on a conjugate joint system and are contained within an anastomosing alteration envelope in a metadiorite body. Reserves were estimated on the basis of fire assays of channel samples and car load samples from underground mine openings, surface and underground diamond drilling and surface trenching. A semi-variogram constructed from channel samples along one of the drifts yielded a horizontal, regionalized influence of approximately 9.0 m. Common industry practice has been to use 6.1 m for similar deposits in Ontario. Proven ore was defined from underground openings. The maximum extrapolation distance for proven ore along strike and dip from a data point is taken to be 6.1 m. Probable ore is extrapolated 7.6 m from a data point in a mine opening or from a drill intersection. Possible mineralization is based on geological continuity one-half the distance to a neighbouring data point.The mineral inventory estimate of 1.45 million tonnes at a grade of4.8 g Au/tonne gives an excellent outline of the geology of the deposit. The deposit contains 313 000 tonnes of ore reservesat a fully diluted grade of6.9 g Au/tonne. These figures include dilution for several reasons: (I) a 2.1 m mining width is used rather than the more typical 1.5 m width to allow for over break because of the shallow dip of some vein zones; (2) over break is allowed for adjacent to major unmineralized dykes; and (3) grams of gold are deleted from estimates to allow for the mining of unavoidable minor dykes.A personal computer with off-the-shelf software was used to compile 712 geologically defined ore blocks and sort them into a number of revealing categories. The computer was used to perform grade sensitivity tests, as well as to evaluate depth potential. Hopefully, the reiterative aspect of the method has randomized the errors and helped to cancel their effects."

Jan 1, 1987

By T. Gerritsen, R. MacRosty, R. Pula

For several years Hatch has been installing fibre optic temperature sensors on the copper cooling elements of smelting furnaces to improve monitoring capabilities in critical locations. The metal/matte tapblock is a key area to monitor in the furnace as it undergoes severe wear from the molten material repeatedly drained through it. The high wear rate around the tapblock means downtime is necessary to perform refractory repairs. A good understanding of the tapblock condition allows the operation to maximize safety and production; consequently the metal/matte tapblocks have been the focus of this study. Fibre optic technology allows the installation of numerous sensors in locations that are very sensitive to refractory thickness, thereby providing information previously unavailable with traditional measurements. The transient nature of the thermal response to tapping and the three-dimensional geometry of the tapblock confound the interpretation of refractory thickness from temperature measurements. This paper focuses on the analysis of both plant data and thermal modelling simulations and details the progress made in relating the temperature measurements to the refractory thickness in front of the copper tapblock.

Jan 1, 2014

By Greg M. Hollyer

The search for minerals in the future will be dominated by deeper exploration and the need to accurately target ?blind? deposits as more and more of the ?easy? near surface targets are exhausted. In this context, key technologies are emerging for deep exploration both in grassroots and minesite exploration, including the Titan 24 Deep Penetrating geophysical technology. Introduced in 2001, this technology has grown rapidly into an accepted approach for exploration in a variety of geologic environments, including brownfield environments where discovering additional reserves would most quickly benefit companies. Titan 24 belongs to a new class of sophisticated Distributed Acquisition Systems (DAS) which record high-volume, high-quality data simultaneously at multiple receiver stations. This data is then processed digitally, modeled using specialized inverse modeling software, and interpreted according to geologic and other parameters. The result is a robust, high-quality, high-volume data sets which provide a basis for improved imaging to depth. In this paper, the Titan 24 distributed technology is discussed. Illustrations of the vast improvement to overall exploration are showcased through results in several case studies. These include examples from two gold deposits, a porphyry deposit and a minesite. These examples show the range of applicability of the technology and the ability to effectively image mineralization, lithology, structure and alteration to depth as an aid to understanding prospective mineral deposits and targeting drills more accurately.

May 1, 2008

By J. Ramirez-Castro, J. A. Finch

"Galena is the finest component of the product of a closed-circuit grind treating a lead-zinc ore, largely due to preferential recycling of this high-density mineral by the cyclone. For example, at the Pine Point Mines concentrator, for ~ 55% -200 mesh over-all, the galena will be close to 95% -200 mesh. This sliming of the lead can limit recovery, selectivity and dewatering. A proposed circuit modification to reduce the sliming is to incorporate a unit cell. A simulator was constructed to study the No. 3 grinding circuit at Pine Point modified by a unit cell on ball mill discharge (BMD).The simulator used a cumulative size basis rate-of-breakage with plug flow ball mill model, the parameters being obtained by laboratory grinding tests. Flotation and the cyclone models used a cumulative recovery/size matrix. The behaviour of each mineral, galena, sphalerite, pyrite and calcite/dolomite, was simulated. Simulation was adapted to a programmable calculator. A close fit to the existing circuit performance at two tonnages and mineral mixes was established.The simulator showed that the modified circuit could significantly coarsen the Pb grind, from 95% to —50% -200 mesh, depending on recovery, without substantially altering the size of the other minerals. The other principal findings were: compared to laboratory flotation tests on existing circuit BMD, the unit cell concentrate (CONC) will be coarser and markedly lower in grade; relatively low unit cell stage recoveries are desirable, because the cyclone scavenges the tail to give a circuit recovery which is higher than the unit cell stage recovery; unit cell stage recovery should not exceed the cyclone stage recovery, as the latter is the maximum circuit recovery; low unit cell stage recovery helps offset the disadvantage of the high flow at BMD; other high-density minerals will also be scavenged into the CONC, as illustrated by pyrite, making CONC quality difficult to maintain; density control of BMD flotation does not greatly alter feed density to the cyclone or ball mill.Possible plant metallurgy is forecast for a CONC diverted to final lead concentrate."

Jan 1, 1980

By G. Robert Guillet

"Ontario enjoys the advantage of its proximity to the large industrial market of northeastern North America. Together with Quebec and fifteen nearby U.S. states, an industrial base of more than half the total for both countries is provided by a population of 100 million.Mineral fillers such as barite, calcium carbonate, kaolin, mica, silica and talc are of major importance in the manufacture of paper, paint, plastics, rubber, vinyl tile, carpet backing, putty, caulks, sealants and adhesives. Ontario has all of these minerals, but domestic production falls short of demand in some cases, and mica and kaolin are not produced at all.This paper reviews the market and outlines the distribution of the major filler-consuming plants of northeastern North America. It also identifies the principal producers of filler minerals in the United States and Canada.IntroductionOf all the uses for industrial minerals, mineral fillers are probably the least understood. Originally used primarily to add low-cost bulk to a variety of commodities without seriously affecting their properties, filler minerals have become essential components that enhance and extend the properties of their hosts. Hence the term ""extender"" which, for all practical purposes, is synonymous with ""filler"". Today, fillers and extenders are not solely low-cost additives, but ingredients that provide essential characteristics to the products they fill.The major markets for mineral fillers are paint, paper, plastics, rubber, adhesives and floor coverings. But there are many others: putty, pesticides, wire and cable coatings, caulking and asphaltic compounds, oilcloth, wall-paper, joint cements, inks, sealants and many others. Barite, calcium carbonate, kaolin, mica, silica and talc are among the more important filler minerals discussed in this paper, but there are at least a dozen others. And the increasing practice of coating the mineral surfaces with certain coupling agents or metal stearates is constantly expanding the range of characteristics and hence the marketing opportunities.Whiteness, particle shape, fineness of grind and cost are the principal considerations in selecting a filler, but other characteristics such as weight, opacity, hardness and chemical inertness may be dominant considerations in specific applications."

Jan 1, 1987

By Heather Budney

Objectives 1. Evaluate the effectiveness of ON?s EA processes using criteria from the EA and policy sciences literature. 2. Recommend improvements to the EA processes and draw lessons from the ON case for the consideration of other jurisdictions. Evaluation Process 1. Chose criteria ? 14 primary criteria (Wood 2003) ? Subcriteria from Wood (2003) and Lasswell (1971) 2. Gathered information ? 6 key informant interviews ? Published literature, policies, legislation 3. Assessed criteria and formed Recommendations

May 1, 2008

By H. L. Gibson, T. N. Setterfield, J. J. Watkins, R. W. Hodder

"The McDougall-Despina fault set in the Noranda district of northwestern Quebec defines the eastern margin of the Despina cauldron, nested within the district-scale Noranda cauldron. The faults are stratabound in that they displace stratigraphy of the cauldron fill, but do not off-set the cauldron cover. The faults are occupied by dikes that acted as eruptive centers to volcanic members of the cauldron-filling sequence. Measurable displacement across the McDougall-Despina fault set is greater than 750 m, and coincident with post-cauldron volcanism. Feeder dikes cross-cut each other and are typically depleted in Na2O and CaO, and enriched in MgO, K2O, Fe2O3and MnO relative to fresh flows. Economic and subeconomic massive sulfide deposits occur adjacent to the McDougall-Despina fault set at different levels over a stratigraphic thickness of 3000 m. These include the Corbet deposit, the subeconomic D-68 Zone deposits, and the subeconomic stringer zones of South Rusty Hill and Bedford Hill. Numerous copper occurrences and abundant hydrothermal alteration occur in and immediately adjacent to the fault set.The McDougall, Despina, and adjacent, parallel, ancillary faults define a synvolcanic fault set which controlled the location of magmatism, hydrothermal alteration and mineral deposition during the early evolution of the Noranda cauldron. Significant sulfide mineral deposition commonly occurred in proximity to the intersection of the McDougall-Despina fault set with northeast-trending synvolcanic faults. Recognition of synvolcanic faults is therefore a major objective of exploration programs for volcanic-associated massive sulfide deposits."

Jan 1, 1995