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By F. L. Pellet, S. Maiolino

"The determination of rock bolt contribution to reinforced joint shear strength is still a challenge, especially for assessing reinforced rock mass stability. For this purpose, several experimental studies have been performed during the last decades, mostly on small scale rock joint and bolt specimens. However, to accurately assess the rock bolt contribution, scale effect has to be accounted for. For this reason full scale lab tests are required as an alternative to in situ tests for which boundary conditions are more difficult to control.In this paper the results of an experimental program carried out with a large shear box, dedicated to test bolts in full scale conditions is presented. Different rock bolt diameters and different rock bolts inclination with respect to the shear plane were tested Experimental results were satisfactorily compared with an analytical model which is able to compute the contribution of the rock bolt to the shear strength of the joint as well the associated displacement of the joint. These conclusions allows us to validate the model in order to help the designer of reinforced rock engineering structures, such as slope or underground openings, to precise the optimum installation of rock bolts. INTRODUCTIONFully grouted rock bolts are commonly used for rock masses reinforcement to ensure the stability of rock slopes and underground cavities. For this purpose, the determination of rock bolt contribution to reinforced joint shear strength is of the utmost importance. During the last decades, several experimental studies have been performed to investigate the behavior of bolted rock joint. For obvious reasons, almost all the experiments were achieved on small scale bolted rock joint specimens (Bjurström, 1974; Azuar, 1977; Dight, 1983; Egger & Fernandes, 1983; Schubert, 1984; Spang & Egger, 1990; Egger & Zabuski, 1991). These studies made it possible to assess the influence of different parameters such as the bolt’s diameter, the number of bolts, the angle between the bolt and the joint, the nature of the rock, the friction and the dilatation angle of the joint. However, to accurately assess the rock bolt contribution, scale effect has to be accounted for (Vallier et al., 2010). For this reason full scale lab tests have been performed as an alternative to in situ test for which boundary conditions are more difficult to control."

Jan 1, 2015

By B. M. Das, D. B. Cross

"In June 1983, the Computer Applications and Process Control Committee (CAPC) of the Canadian Institute of Mining and Metallurgy (CIM) circulated a questionnaire to coal mining, exploration and consulting companies in Canada to determine the industry's level of interest in holding a workshop-style meeting to introduce company personnel to ""state-of-the-art "" computer systems designed to carry out specific technical and management junctions. It was necessary to conduct the survey to determine the specific fields of application and the nature of training which are of most interest.Almost universally, the companies expressed interest in computer workshops and training for applications in the Canadian coal industry. The survey showed that all categories of personnel felt the need for some sort of training. Areas of specific interest identified were: exploration and geology, mine design, reserve calculations, coal mining technology, coal preparation, rock mechanics, ventilation, financial planning, and process simulation. The details of this survey together with an assessment of the significance of computer applications in the Canadian coal industry are presented in this paper."

Jan 1, 1986

By A. J. Harrison

"The introduction of an amendment to the Mines Regulation Act in the Province of British Columbia, passed in July 1974, and similar amendments since enacted by other provinces introduced the Canadian underground mining industry to the use of fire-resistant hydraulic fluids.Few, if any, of the hydraulic circuits in use in underground mining at that time were specifically designed for use with fire-resistant fluids, compared with the increasing number of such circuits conceived and in production today. The technology required in designing equipment for use with fire-resistant fluids may be likened to that associated with conventional mineral oils, but, in many respects, a variety of additional and / or alternative considerations must be taken into account. The fast-increasing use and development of fire-resistant fluids throughout all facets of industry, world wide, during the past 20 years has led to a whole new technology in system construction and component design, whereby acceptable performance can be achieved . However , the transition from conventional mineral hydraulic oils has not been without its problems, particularly when retro-fit of existing units was involved."

Jan 1, 1981

By Dale L. McKinnon, Jean-Pierre Farant

"Dust collectors are used to reduce airborne dust levels generated during crushing at a mining operation and their adequate maintenance is required to ensure effective control of health and safety hazards associated with dusty conditions. Although the pitot traverse technique is commonly employed to balance these dust collectors, the use of an alternative-the equilibrium concentration tracer gas method-is proposed in this paper. This method, which uses sulphur hexafluoride as a tracer gas, can be used to balance airflows in dust collectors and to determine hood collection efficiency accurately and effectively. This technique also reduces some of the errors inherent to pitot tube measurements. IntroductionIndustrial dust collectors are used to reduce dust genera ted by processes like cru shin g, and these must be periodically checked and balanced to ensure continuing effective control of health and safety hazards associated with dusty conditions.To date, the pitot tub e traverse technique has been commonly used to balance air flows in dust collectors. However, this technique is both time -consuming and cumbersome. The equilibrium concentration tracer gas method, described in this paper, is proposed as a viable alternative as it is faster, more reliable, and amenable to automation. The use of tracer gases for such task s is not new. This approach has been used in a variety of mining situations to determine volumetric flow rates in underground openings, leak age through mine stoppings, the effectiveness of face ventilation, pollution migration patterns, mine air recirculation rates, and rock porosity."

Jan 1, 1986

By D. Hamilton

The electrode of a PEM fuel cell consists of two distinct sections - the catalyst layer and the porous transport layer (PTL). There are several kinds of PTL material, although all use carbon fibres as the solid fraction. The fibres can be matted to form a paper, woven into a cloth, or chopped to form a felt. Despite the different morphologies of the media, they are all anisotropic in structure, that is the majority of continuous fibres lie perpendicular to the direction of bulk transport. Currently, no models account for anisotropy and all transport coefficients are calculated as volume weighted averages or from empirical correlations (not developed for fibrous porous media). The present work presents a new methodology for determining anisotropic transport coefficients in fibrous porous media. A numerical experimentation process is employed wherein random samples of the PTL are generated and used to solve a diffusion transport equation. Effective transport coefficients are determined by integration of flux across the domain boundaries once a steady state solution has been reached. Multiple random samples at each porosity are generated in order to predict statistical variance. The results are correlated for ease of implementation in full PEM models.

Jan 1, 2005

By D. G. Dixon

A novel technology for leaching copper from primary copper concentrates has been developed at UBC. This patented technology takes advantage of the galvanic couple between pyrite and chalcopyrite to ensure rapid and complete oxidation of chalcopyrite under mild conditions in acidic iron sulfate solution, without the need for microbes, ultrafine grinding, or chemical additives such as chloride, nitrate, or surfactants. Copper recoveries of 98% or greater can be achieved at 80°C under atmospheric conditions in as little as 4 hours of residence time. The process is selective for chalcopyrite over pyrite, generates near-quantitative levels of elemental sulfur, and is fully compatible with conventional solvent extraction and electrowinning of LME Grade A copper cathodes. In this paper, the fundamentals of the Galvanox ? process are reviewed, and selected results of batch leaching tests on various concentrate samples are presented and discussed.

Jan 1, 2007

By L. Mercier, A. El-Hsaeri, L. Amaratunga

Laboratory scale studies of the development and application of high capacity heavy metal ion adsorbents with uniform nanoscale porosity (denoted MP-HMS, mercaptopropyl - hexagonal mesoporous structure) to extract gold from solutions is described. The adsorbents are selective towards gold ions. The adsorption capacities of these materials are also among the highest reported. MP-HMS has shown the capability to adsorb 330-mg gold per gram adsorbent (up to 30% of their weight). Gold uptake by the adsorbent was found to increase dramatically with solution agitation. The adsorbent was found to be extremely effective in adsorbing gold ions from ultra- low concentrations, like those found in mine effluents. Experimental studies indicated that MP-HMS maximum adsorption of gold (99.9%) occurred under all solution concentrations. Another promising attribute of these materials is their favorable adsorption kinetics. The contact time required for 80% adsorption of gold was found to be less than 60 seconds. The efficiency of these nanoporous materials for the recovery of gold from mining effluent is evaluated and their prospect for application in the mining industry discussed. The process thus has the prospect of becoming an efficient and environmental friendly method to recover gold from aqueous solutions, such as gold mill effluents.

Jan 1, 2004

By Z. -G. Ren, J. -S. Qian, Y. -G. Yang

The waste slags from chemical and metallurgical plants contain approximately wt 1% water soluble Cr6+. This hexavalent chromium is very harmful to human health, and the treatment of the slags has concerned metallurgists for many years. A sintering method was developed to treat the waste slag. In this process, sinter was made from a mixture of the waste slag containing hexavalent chromium, iron concentrate and coke breezes. During sintering, hexavalent chromium was reduced to trivalent chromium. The latter is known as a non-harmful material and can be used as chromium resource for the production of ferrochromium or chromium-containing cast iron. After sintering the hexavalent chromium in the sinter could be reduced to less than 0.0008%. It was found that the waste slag with fine particles was favourable to the Cr6+ removal. An increase of carbon content in the sintering mixture could increase the rate of Cr6+ removal and the strength of the sinter produced. The rate of Cr6+ removal increased with increasing basicity of the sintering materials with basicity less than B=1.8, above which it decreased with increasing basicity. Blast furnace was found to operate smoothly when using the sinter made from the waste slag containing chromium. However the productivity of sintering machine was slightly low compared to the sintering operation using ordinary raw materials.

Jan 1, 2004

By M. R. Shadnam

This contribution provides an assessment of research and development efforts to optimize SOx, NOx and mercury capture in flue gas. Coa, characteristics and combustion conditions in a power plant have an impact on the types and concentration of flue gas pollutants. These factors can also affect the amount of pollutant removed. This contribution would also provide a comparative study of the technologies that holistically aim remova, of SOx, NOx and mercury altogether in coal-fired power plants. A portion of this contribution provides background information on regulatory drivers.

Jan 1, 2010

By I. A. Cameron

In 1979, John Peacey and William (Bill) Davenport published The Iron Blast Furnace Theory and Practice billed as "An up to date and comprehensive treatment of blast furnaces from fundamental principles to modern operations" (back cover). As a 1979 graduate of McGill University’s Metallurgical Engineering program, I belonged to the last "beta" student group which completed the prescribed blast furnace course work before The Iron Blast Furnace Theory and Practice was published. As my career developed, I become an international blast furnace consultant and have worked with blast furnace operators and raw material suppliers on 5 continents. The blast furnace is the dominate iron making process responsible for 70% of global steel production. Blast furnace engineers have implemented many improvements by manipulating the blast furnace process metallurgy using the principles presented by Peacey and Davenport to reduce coke consumption and increase oxygen usage and blast furnace productivity. This paper briefly summarizes some key principles presented by Peacey and Davenport (1979), describes process improvements made by blast furnace operators over the 35 years since The Iron Blast Furnace Theory and Practice was published and outlines important future developments in blast furnace technology.

Jan 1, 2014

By Dani J. Alldrick, Alastair J. Sinclair, Colin I. Godwin

"The Stewart mining camp has a long history of precious and base metal mining. The camp is abundantly mineralized, with more than 200 widespread, varied, vein prospects, deposits and orebodies. These show wide variations in the mineralogy of ore, gangue and alteration assemblages, and wide variations in textures and structural settings. This report establishes the timing of the different metallogenic epochs and suggests a specific exploration application for systematic leadisotope analyses.Galena lead isotope ratios from a range of mineral occurrences indicate that all these varied deposits formed during two main mineralizing events. Lead isotope data from the Stewart mining camp do not provide absolute ages for the formation of mineral deposits, but the relative distributions of data are consistent with dates determined in other studies. One ore-forming episode occurred in the Early Jurassic and the other in the Middle Eocene. Both metallogenic epochs were brief, regional-scale phenomena. Some deposits from the younger mineralizing episode were emplacedadjacent to or superimposed on the older deposits.Field and laboratory studies show that the two metallogenic epochs are characterized by different base and precious metal suites: Early Jurassic gold-silver-zinc-lead-copper; and Middle Eocene silver-lead-zinc. Therefore, showings of different ages have different base and precious metal potentials and deserve different exploration emphasis. Lead isotope studies provide a reliable, cost-effective method for evaluating the age and commodity potential of small or recently discovered mineral showings and for setting exploration priorities on properties with several varied mineral occurrences. The determination of the age and metal potential of a prospect at an early stage of exploration may govern the urgency, intensity or even the necessity for further exploration work."

Jan 1, 1993

By Pierre Bénard

To achieve penetration on the energy market, hydrogen must overcome obstacles in the areas of storage, safety and infrastructure. One of the most important is the onboard storage of hydrogen for transportation applications, where large performance gaps exist between the current state of the technology and user expectations. In order to develop and demonstrate viable hydrogen storage technologies for cars, a set of gravimetric and volumetric system targets have been proposed by the US Department of Energy, based on achieving a driving range of 500 km for a hydrogen powered vehicle. A factor of 2 to 3 improvement in both hydrogen storage capacity and energy density is needed along with several other performance goals. Another key issue is safety. Although some of the safety issues can be arguably assigned to misperceptions, hydrogen has specific properties that have to be addressed, particularly in confined geometries where the risk of hydrogen detonations becomes an issue.

May 1, 2007

By W. A. Grell

"The oxygen meter has been in use at MacLeod Cockshutt Gold Mines for over a year, At MacLeod about 200 tons per day of reground concentrate containing roughly 10% pyrrhotite and 20% pyrite is cyanided in four 181 x 18' Dorr agitators. A survey by the Department of Mines showed that oxygen content of some of the agitators was rather low. Experience with our oxygen meter indicates that the oxygen content must at times have been too low for good gold dis solution.We have found that in winter, when pulp temperatures drop to about 50° F, oxygen saturation in the agitators is not difficult to maintain. In summer, however, when pulp temperatures rise to 70or 75°F, the oxygen content will drop very readily. It was found that a high oxygen content can be maintained readily if the pulp is sufficiently dilute. Thus at 50° F, a pulp of specific gravity 1. 75 i.e., about 55% solids, will saturate; but at 70 or 75° F, the specific gravity must be decreased to 1 .45, equivalent to about 40% solids, in order to maintain saturation. Very thick pulps, such as thickener underflows, are noticeably difficult to saturate in the laboratory, and lose their oxygen rapidly.Clear solutions, on the other hand, absorb oxygen readily and hold it. The primary thickener overflow, before agitation, is 100% saturated; after storage of 3 to 4 hours it is still 100% saturated at re clarifier tank. Barren solution after spraying in a launder is 100% saturated.We have not yet attempted to determine what percentage saturation is necessary for good extraction, but it is known that there is a point at which extraction decreases rapidly. So far, the measures required to maintain over 80 or 90% saturation have coincided with measures required to hold the reducing power to the point believed necessary."

Jan 1, 1964

By Jonathan Tsang, Ali Merati, Jonathan Beddoes

Due to economic factors, many aircraft in service today have been operating for more than 30 years even though they were initially designed with a service life of 20 years. Improved damage management models are therefore needed for use in life prediction and management of the aging fleets of aircraft. Currently, the generally accepted procedure in fatigue life prediction methodologies is to back calculate the equivalent initial flaw size (EIFS) using established long crack growth data. However, it was observed from studies carried out at the National Research Council Canada that nucleation and short crack growth constitute up to -95% of the fatigue life. As a result, it seems that the significance of the short crack regime has been underestimated and must be further investigated and fully understood before an accurate holistic life prediction methodology can be realized. Unlike long cracks, local microstructural features such as grain boundary, grain size, inter-particle spacing, and texture play dominant roles in the behavior of short cracks. An extensive study has been carried out to evaluate different crack detection and monitoring techniques in the short crack regime for AA2024-T3. The results will be presented in detail.

Jan 1, 2004

By P. Woo, N. Brodusch, R. Gauvin, H. Demers

The scanning electron microscope (SEM) was primary developed for imaging applications. With the introduction of the Si(Li) energy dispersive spectrometer (EDS), simultaneous imaging and x-ray microanalysis became possible. However, long working distance and high current were needed because the position and small solid angle of the EDS detector. The high spatial resolution is generally obtained at short working distance with a SEM. Unfortunately x-ray microanalysis is never performed in the best imaging conditions. The annular silicon drift detector system is inserted below the objective lens which gives a higher solid angle (up to 1.3 sr). In consequence, a lower working distance and probe current can be used. An improved spatial resolution becomes possible during x-ray microanalysis. With this x-ray detector installed on a cold-field emission scanning electron microscope, quantitative x-ray microanalysis with high spatial resolution at low beam energy and low current becomes possible with the possibility of using the various different type of imaging at the same time. Also, since the count rate can be as high as 1,500 kcps, which lowers significantly the detection limit of elements as well as the minimum feature sizes of different phases that can be distinguished.

Jan 1, 2014

By T. P. Kostek

"Historically, gear pumps and motors have been popular in the mining industry because of their competitive cost, simple yet rugged construction, ease of rebuild, and relative long life and insensitivity to contamination. However, with the ever increasing ""popularity"" of fire-resistant hydraulic fluids, both users and manufacturers of gear equipment must make special considerations to enable the equipment to continue giving satisfactory performance even with the water-containing fluids.The paper discusses 60-40 invert emulsions and waterglycolsIntroductionMuch information has been published on the specific characteristics of the various types of fire-resistant hydraulic fluids. Fluid manufacturers' literature and other publications have dealt with such specifics as fire resistivity, seal compatibility and wear rate characteristics. Gear pumps and motors have been, and will continue to be, applied successfully in hydraulic systems employing both the ""invert"" emulsions (60-40) and water-glycols as the hydraulic fluid.Because most external spur gear equipment has been designed to function with petroleum oil as the fluid medium, certain guidelines must be followed to ensure satisfactory service life. FluidsThere are a number of different types of fluids which fall in the category of"" fire-resistant"" , the most common'being phosphate esters, water-in-oil emulsions, oil-in-water emulsions and water-glycols. The two in most prevalent use today as hydraulic fluids are the water-in-oil emulsions and the water glycols"

Jan 1, 1980

By Andrew Bamber

Outline ?Background to Mine-Mill Research at UBC ?Mine Mill Integration ?In situ mining methods ?Underground Pre-concentration ?System Design and Supporting Technologies ?Case Studies: ?INCO -McCreedyEast Mine ?Placer Dome ?Porcupine JV ISL Study ?Musselwhite, South Deep ?Falconbridge ?Fraser Copper ?Thayer Lindsley ?Wayside Gold, other scoping studies? ?System Designs ?Summary ?Future work ?Conclusion

May 1, 2006

By E. Kordzadeh, M. Reza Bateni, M. Karaminezhaad, A. Moeini

A series of austenitic heat resistant Fe-Ni-Cr-Al alloys with different nickel contents have been investigated at 1100 ° C and 25, 50, 50,100 hours in S/0 bearing atmospheres. Before sulphidation test, the specimens were annealed in argon at 1250 °C for 8 hrs. Weight changes were measured using an automatic thermo gravimetric analyzer and corrosion products were analyzed by scanning electro microscope (SEM), energy dispersive X-ray spectrometry (EDAX), X-ray diffraction and optical microscope. The results showed that sulphidation resistance decreased with increasing nickel content. Internal sulphidation controlled by gaseous transport through cracks and pores and the formation of internal sulphide increased when liquid sulphides formed on the surface.

Jan 1, 2004

By Robert B. Parsons

"Thrashing one's way through a jungle of entangled tax rules is no easy task today, as Canada's legislators continue to complicate this country's income tax laws. At some magical point, there is presumably some balance to be struck between legislation which is equitable and unambiguous on the one hand, and at the same time is efficiently complied with and administered. It is becoming increasingly clear that the legislation is not in balance, and that there is a pressing need for some simplification of the income tax rules and regulations especially in areas of critical importance to the resource industries-even though such simplification will likely involve some sacrifice of equity and certainty.Introduction""I would wish that ... the superfluous and tedious statutes were brought into one sum together, and made more plain and short, to the intent that men might better understand them."" Edward VI, King of England 1547-1553.Regal decree notwithstanding, the legislation of most developed nations continues to become more complex, lengthy, and confusing than ever before. Canada's income tax system cannot escape the accusatory finger pointing at examples of this serious problem which plagues all of us today.Although many areas of our tax law could easily warrant some degree of simplification, for those who are involved with this country's resource sector, that horrendous, almost unreadable, part of our tax legislation which deals with resource taxation must be regarded s a prime candidate for simplification. In recent decades, but particularly in the past ten years since tax reform in 1972, budget after budget, both federal and provincial, have amended, massaged, modified, and manipulated the resource tax rules to the point where not only are taxpayers totally lost in their attempts to make some sense of the entanglement of rules, but also the draftsmen themselves acknowledge that the outer limits of complexity are being reached, and that the whole set of rules is on the verge of grinding to a groaning halt under its own weight of nonsense and frustration."

Jan 1, 1982

By Brian Penney

"The Iron Ore Company of Canada (IOCC} has mined and processed an iron deposit in Western Labrador along the Labrador-Quebec border since the early 1960' s. Current capacity is approximately 19 million tonnes of concentrate, 70% of which is converted to pellets at these facilities.The ore deposits are located in hills rising 150 to 300 meters above the adjacent lakes, and most of them are covered by very little overburden. The iron minerals are mainly specular hematite and magnetite hosted in a quartz formation. Crude ore averages 40% Fe that is concentrated to 65.5% Fe. IOCC is an extensive operation extending from Labrador City NF to Sept-Iles Quebec. It consists of open pit mining, concentrating, pelletizing, railway, and dock loading facilities.The Concentrator liberates iron from the silica by crushing and grinding the ore to -14 mesh (-1190 microns}. Ground ore is concentrated in spirals and filtered for transportation. Spiral tailings are treated in a Magnetic Recovery Plant (Mag Plant} that recovers lost magnetite. Mag Plant tailings are treated in a Hematite Spiral Plant (Hem Plant} that scavenges fine iron remaining in this stream.This report deals with ongoing iron recovery initiatives within the ConcentratorIron Losses in the ConcentratorIron recovery at IOCC is approximately 70.5%. This compares with recoveries that range from 65% to 86% for other iron mines in our area. Other world large iron ore producers dig and ship concentrate quality ore directly out of the ground and have an effective recovery of 100%. With increasing costs for labour, equipment, and supplies an increase in iron recovery is required to keep the operation viable.More than 90% of our iron concentrate is produced by gravity separation using spirals. The physical characteristics of the iron minerals that most effect recovery are mineral grain size and degree of liberation. We divide ground ore into three size categories -coarse, intermediate, and fines. A brief description of each size fraction follows:"

Jan 1, 1996