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By A. S. H. Kabir

Due to the high specific strength and excellent corrosion resistance, Ti-6A1-4V has been widely applied in aerospace industries. In this study, the welding performance of 3.2-mm and 5.1-mm thick Ti¬6A1-4V sheets was studied using a 4 kW continuous wave Nd: YAG laser. It is found that the use of filler wire, matching the parent metal composition, can bridge the joint gap and produce full penetrated welds up to a width of 0.6 mm without cracking. The laser welds were characterized in terms of the bead geometry, defects, microstructures, and hardness. With increasing joint gap, the percent porosity area increased, reaching just over 1% of the fusion zone area at a gap width of 0.6 mm for the 3.2 mm and 5.1 mm thick sheets. The maximum underfill depth in the Ti-6A1-4V laser welds was about 5% or 7% of the sheet thickness for the 3.2-mm and 5.2-mm thick materials, respectively, meeting the AWS D17-1 specification. The microindentation hardness was maximum in the fusion zone and sharply decreased through the heat affected zone until reaching the base metal value.

Jan 1, 2011

By Qing-hua Tian, Li-then Cheng, Xue-yi Guo

In order to recycle valuable metals from silver separated residue, a novel method using alkaline smelting at low temperature was proposed. The main factors affecting the main metal recovery such as the smelting temperature, smelting time, liquid-to-solid ratio and alkali addition were investigated comprehensively. The behavior of the main metal elements, such as Pb, Sn, Sb and Bi in silver separated residue was also discussed. The results indicated that amphoteric metals such as Pb and Sn can be smelted into the melt, while other metal elements, such as Sb and Bi were left in the residue.

Jan 1, 2011

By L. M. Amaratunga, G. G. Hein, D. N. Yaschyshyn

Fine tailings produced in the milling process have traditionally been disposed of in tailings ponds. Attempts have been made to use these fine tailings in backfill, however, to date the majority of backfill operations have utilized only a small percentage of fines. The remaining fines are, therefore, being sent to tailings ponds creating a waste disposal and environmental problem. This disposal practice is even more acute in the gold milling industry where fine grinding, required for value liberation, results in the production of large quantities of fine tailings, of which a large percentage cannot be used in backfill. Through Cold-Bond Tailings Agglomeration (CBTA), these fine tailings can be agglomerated into pellets which can then be used as a coarse aggregate in back-fill. This paper presents the results of using these pellets to create an Agglomerated Tailings Paste Fill (ATPF) made entirely of fine gold mill tailings and cementing binders. Through this process, supplementary imported aggregates such as sand, gravel, rock-chips are not required while still maintaining adequate back fill strength. By using this CBTA technology, fine tailings are diverted from tailings ponds and becomes utilized as a value added resource in the form of aggregates for use in paste fill.

Jan 1, 1997

By Roger K. M. Bellows

The last coal-fired power plant to be built in Canada came into operation in 1994. Since then, Canada?s electricity requirements have grown substantially but no new coal-burning plants have been built. This country has abundant resources of coal from coast to coast, but in recent years, this has not affected our choice of fuel. In many other countries this is not the case, and the use of coal is growing rapidly. Although this presentation covers the topic from an Alberta perspective, some of the conclusions can be extrapolated to the rest of the country, and perhaps even to other countries. The coal found in the Alberta plains is particularly attractive because of its low cost and low sulphur content. Yet coal is no longer the fuel of choice, and a long-standing provincial government policy to favour coal for electricity generation has been ignored for more than a decade. Considering the lack of good alternatives, it seems obvious that we should look to coal as our primary energy source in the generation of electricity and for other industrial applications. This paper discusses some of the reasons that coal has fallen out of favour, particularly with respect to electricity generation. The significance of the deregulation of the electricity industry will not be ignored. In addition, the author will offer his opinion on the question of what it will take in order for coal to once again become the favoured fuel.

May 1, 2001

By P. Amelunxen

It is well-known that the particle breakage mode that occurs in a semi-autogenous mill is significantly different from that which occurs in a ball mill, enough so to warrant very different lab scale breakage tests and scale-up models. This phenomenon, at the plant scale, leads to changing process constraints depending on the particular properties of the ore. For example, hard or coarse ores might bottleneck the SAG/AG mill throughput, while the ball mills might constrain throughput when milling soft or fine ores. Because the power draw of a ball mill is fairly constant compared to that of a SAG/AG mill, periods of SAG/AG mill bottlenecks lead to increased ball mill circuit specific energy consumption and a finer grinding circuit product size, which together constitute a loss of efficiency of the overall process. Because HPGR circuit throughput is less sensitive to changes in ore hardness, this situation is less common or severe in those circuits. Furthermore, the ball mills are somewhat decoupled from the upstream crushing circuits through the use of surge bins, which also helps to mitigate this effect. As a result, ore hardness variability constitutes a significant cost penalty that should be applied to SAG mill/ball mill/pebble crusher SABC circuits when evaluating the relative economics of different grinding circuit configurations. Nevertheless, the issue is by-and-large ignored, because most current HPGR trade-off studies are based on averaged ore hardness parameters. This paper provides an estimate of the magnitude of this penalty for a typical operation by using Monte Carlo simulation methods and plant data from Freeport-McMoRan?s autogenous, semi-autogenous, and HPGR-based comminution circuits. A case study from an in-house 96K t/d sulphide project is presented to illustrate the concept. It was found that by including variability effects, the trade-off NPV of the HPGR circuit over that of the SAG mill circuit increases to $84 million from negative $33 million, effectively reversing the original decision of selecting a SAG mill circuit for the fixed hardness case.

Jan 1, 2012

By D. A. Karvonen

In 1970, the Government of Saskatchewan instituted a program aimed at resolving the dilemma of excess productive capacity over the market demand which existed for potash produced in Saskatchewan. The two primary elements of the program were prorationing of potash production to market demand and a minimum selling price. The paper reviews the factors, both local and international in nature that led to the introduction of the program. The licensing mechanics and the operation of the program, along with the changes that have been introduced in two and one-half years of operation, are discussed. Attention is given to the results of the controls as they affect the industry and the province. Also discussed is the outlook for Saskatchewan potash in world markets.

Jan 1, 1973

By J. D. Wright

This paper describes current milling practice at Endako Mines Ltd., a molybdenum producer in central British Columbia. The various steps in the crushing, grinding and flotation of the ore are outlined, with emphasis on the metallurgy of the latter operation. Tailings disposal and concentrate assaying methods are also described.

Jan 1, 1969

By M. Mirnezami, J. A. Finch, S. Uddin

A fast, reliable and practical way of measuring zeta potential using sedimentation potential method is proposed. A cell was designed along with the instrument control software to determine the required variables simultaneously i.e. sedimentation potential, specific conductivity, volume fraction of solid as well as pH. High purity alumina and silica powders were used as test samples. Measured zeta potential using the proposed technique was comparable with the results by electrophoresis.

Jan 1, 2009

By Ralph L. Rutherford

Geologists or mining engineers familiar with geology are frequently requested by mine operators to give correlation in-formation regarding some mining property with respect to an adjacent area on one at some greater distance. It is the object of this article to mention a few of the difficulties involved in securing this information and to point out some of the salient factors upon which correlation is dependent. In view of the nature of the following discussion, a brief statement of the general character of coal formations .. seems appropriate. Coal formations, by reason of their environment of deposition which is in fresh or brackish water, exhibit the features common to continental deposits, in contrast to those of marine deposits. Such deposits are characterized by rapid variation in thickness and in lithological character both later-ally and vertically. (Plate 1 A). They consist essentially of sandstones and clay shales with all gradations between them, and also a few beds of coal and frequently some conglomerates.

Jan 1, 1924

By A. Koning, P. Lauzon

Pressure hydrometallurgy operations require vessels to be lined with an impermeable membrane for corrosion protection and one or more courses of refractory or ceramic brick. Examples of unit operations that utilize composite lining systems include pressure oxidation autoclaves, sulphide precipitation autoclaves, chloride leach reactors, flash vessels, cyclone separators, and direct contact condensers (heater vessels and quench vessels). The refractory lining must satisfy multiple requirements: it must thermally insulate the membrane from process fluid, be structurally stable, provide erosion resistance, be chemically compatible with process fluid, and provide an economic service life. New hydrometallurgical processes are pushing the pressure, and temperature, with each new generation of plants. A fundamental understanding of all factors affecting the mechanical stability of the lining system is essential as lining designs move further away from the industry's experience base. The impact of irreversible chemical swell, operating factors, design factors, and installation factors are presented based on modifications to the traditional one-dimensional mechanical stress model. A new stability criterion - that the brick lining remain in contact with the steel shell membrane - is presented. This new stability criterion imposes new restrictions on the lining design.The effect of geometry and adding additional degrees of freedom to the analysis is explored using two-dimensional and three-dimensional Finite Element Analysis (FEA). The effect of these additional degrees of freedom on the results of the one-dimensional model are discussed.

Jan 1, 2004

By W. N. Hamilton

As a result of a test-drilling program conducted by the Research Council of Alberta in 1968, a gypsum deposit averaging 30 feet in thickness, with a chemical purity of 84 per cent gypsum, has been proven to underlie the Clearwater River valley for a distance of 18 miles at depths ranging from near-surface to 300 feet. This and other subsurface deposits in the vicinity of Fort McMurray, Alberta are the product of local hydration of anhydrite beds believed to be the water-insoluble remains of the leached Prairie Evaporite formation of Middle Devonian age, the thick salt section of which is preserved down dip. The effects of salt solution are seen in the disturbed bedding and the intermixture of greyish green shale with gypsum in the core, the shale content being responsible for the rather low chemical purity of the deposit. A similar gypsum deposit, but probably of higher purity, is postulated to occur beneath the Athabasca River valley about 60 miles north of Fort McMurray.

Jan 1, 1969

By Farzad Khodabakhshi, Adrian P. Gerlich

"Multi-pass friction stir processing (FSP) was performed to fabricate a new Al-Mg-Graphene nanocomposite. Microstructural developments and distribution of graphene were studied by using electron backscattering diffraction (EBSD) and transmission electron microscopy (TEM) analysis. In the stirred zone (SZ), grain structure was refined down to about 2 µm attributing to the operative dynamic restoration mechanisms and the locking effect of graphene phase. As a result, the yield strength of Al-Mg alloy was improved more than two times due to incorporation of graphene nano-sheets. Also, the indentation hardness resistance of nanocomposite was increased up to ~60%.INTRODUCTION Aluminum-matrix nanocomposites have garnered significant in recent years due to their superior performance and potential advantages for several industrial applications including the automotive and aerospace sectors. Among various reinforcing nano-materials, carbon-based structures featuring sp2 or sp3 hybridization bonds have been found to offer considerably improved physical and mechanical properties. Such carbon allotropes form at micro- and nano-scales including; graphite, carbon nano-tube (CNT), nano-fiber, and graphene. The potential of two-dimensional (2D) carbon materials was introduced in 2004, with the development of graphene as an alternate 2D allotropic form of the carbon structure with a honey-comb lattice at the atomic-scale. It has been shown that it is currently among the strongest materials ever tested with an intrinsic tensile strength of 130 GPa and Young’s modulus of 1000 GPa, and also offers unique thermal and electrical properties.To fabricate metal-matrix nanocomposites reinforced by graphene nano-sheets with typical metallurgical processing techniques, some attempts have been reported in the literature for various solid-state techniques including; hot rolling, mechanical alloying, and friction stir processing (FSP) of pre-cast plates or surface dispersed graphene oxides. The main challenge in those methods was to facilitate the considerable high temperature and pressure for attaining a uniform dispersion of the nano-sheets during the consolidation process. In most cases, significant difficulties have been reported in obtaining a uniform dispersion of graphene within the metal matrix. Among various techniques for production of metal-matrix nanocomposites, FSP has attracted significant attention as a method of surface modification since it was first reported by Mishra et al. In this process, a non-consumable rotating tool is plunged into the surface of material for the aim of microstructure modification. Extreme material plasticity is induced without melting as a result of friction between the tool and workpiece. Frictional heating and severe plastic deformation induced by the FSP process enables metal matrix nanocomposite fabrication by softening the base material and mechanical stirring to disperse the reinforcing nano-materials into the matrix."

Jan 1, 2017

By Gilles Tremblay

The legacy of orphaned/abandoned mines, with their associated environmental liability, human health concerns and the financial costs of clean up is a serious issue facing Canada. In 1999 and 2000, a number of stakeholders put forth requests to Mines Ministers to establish a joint industry-government working group, assisted by other stakeholders to review the issue of abandoned mines. The Ministers supported this initiative and asked that a multi-stakeholder workshop be organized to identify key issues and priorities. The Workshop on Abandoned Mines, held June 2001 in Winnipeg, developed consensus, guiding principles and recommendations that were presented at the Mines Ministers? Conference, September 2001. Ministers agreed on the importance of a large-scale program for the rehabilitation of orphaned/abandoned mines sites. A multi-stakeholder Orphaned/Abandoned (O/A) Mines Advisory Committee was formed and a plan was developed to study various issues relating to the implementation of remediation programs across Canada. Three task groups were formed to address the following key areas: Information Gathering; Community Involvement; and Barriers to Collaboration. The presentation will include a summary of the results of the three projects and the future work plan for the program.

Nov 1, 2002

By K. Huang, L. Pan

"Darcy’s law has been used extensively to model cake filtration. It is a macroscopic model, in which particle size dominates the kinetics and cake moisture. In the present work, a capillary flow model has been developed from first principles to study the effects of microscopic parameters such as capillary radius, boundary layer slip, disjoining pressure, and surface tension that may be important for dewatering ultrafine particles. Laboratory-scale pressure filtration tests show that dewatering kinetics is strongly dependent on capillary radius, which in turn is influenced by surface hydrophobicity, surface charge, and length scales of particles. The model parameters determined from laboratory-scale filtration tests show that use of a hydrophobizing reagent can greatly improve fine particle filtration due to increased slip and decreased capillary pressure. The kinetics of dewatering kaolin clay is fastest at a pH where the layer-structured particles coagulate with a face-to-edge orientation. The capillary flow model developed in the present work may be useful for designing filters and optimizing operating conditions.INTRODUCTIONIn 2014, Canada produced 2.2 million barrels per day of crude oil from the oil sands resources in Alberta, which is expected to grow to 3.2–4.0 million barrels per day by 2030 (CAPP, 2013). One of the challenges to meeting these projections is the tailings management. At present, the industry uses ?77 km2 of the lands to construct tailings ponds. Significant amounts of the tailings disposed to the ponds are silts and clays that are slow to settle and consolidate, creating problems for reclamation. It is, therefore, the objective of the present work to develop a filtration model that may be useful for developing advanced dewatering technologies that can address the tailings management issues.Darcy’s equation is the governing law for filtration. It was derived as an empirical model by H. Darcy in 1856 while he was studying fluid flow in sand filters (Hall, 1956). Since then, many investigators derived it from first principles. It relates superficial fluid velocity to the pressure drop across a porous medium of known permeability. In filtration, the latter can be related empirically to particle size using the Kozney equation (Yoon, 2005)."

Jan 1, 2016

By J. C. Rudolph

"THE TOPIC on which I am speaking this afternoon is ""The Future of the Canadian Oil Industry.'' At the time of C + 100, we should take a searching look at ourselves, an honest appraisal of our achievements and a forthright accounting of our shortcomings as well as the uniquely Canadian aspects of this industry. I would like to put before you some of my views on the direction we are taking in the exploration field and in the production field. I would also like to speak briefly on some of our problems and the role of the various segments of our industry in solving these problems.First of all, let us look at the exploration picture. We are in the midst of an exploration boom. There were 133 seismic crews active in Western Canada this winter, the highest since 1957, land prices are appreciating rapidly, Canadian oil reserves increased + 16 per cent during 1966, there is a great demand for technical personnel of every kind and the whole industry, except the drilling segment, seems to be prospering. This surge of activity has its roots in two major occurrences. The first of these was the change in the pro-ration system in Alberta, the major producing province, accompanied by the change in spacing pat-terns. The proration change was designed primarily to encourage in-creased exploration and it has certainly had this effect. It has also had the unforeseen effect of put-ting everyone into what we, in the oil business, call ""elephant hunting."" In other words, the days of the development of barely economic, marginal fields are over. Oil companies today are only interested in high-reserve, high-productivity, high-quality reservoirs."

Jan 1, 1968

By D. J. McCulla

Mineral development and utilization affect the health of the economy and the pattern of long-term development throughout Canada. There are many diverse opinions on the contribution of minerals to the economy, but there is a dearth of adequate quantitative information. This paper discusses some recent research and provides some new information.

Jan 1, 1977

By E. T. W. Bailey

A HISTOR Y of the development and application of instruments, from the simplest U gauge to a modern indicating recording controller, would contain many interesting accounts of difficulties experienced and over-come. Important as is the history of development to any branch of science, this phase will, of necessity, have to be omitted from this paper and remarks confined to the results from the use of instruments in their present form. The steel industry bas, in the past decade, become increasingly instrument minded. More than ever, economy and adherence to doser specifications are demanded, and any tool that will aid in attaining these objectives by intelligent application and use finds a ready acceptance. The open-hearth furnace bas offered a field for instruments which is different from almost any other and one in which even a small percentage saved in operating costs may represent a considerable sum. Nevertheless, this department of the steel industry has been more cautions than most others in accepting the benefits which automatic control bas given on many other types of industrial furnaces, and one is puzzled why open hearths have not more generally benefited by the application of controlling instruments. The furnace operator bas to adjust the same three main valves that control fuel, combustion air, and stack draft as on most other furnaces, with the additional regulation of reversing the furnace. He is just as aware of the importance of proper draft control and correct air volume to burn most economically the applied fuel as any good boiler-plant engineer. What, then, are the special conditions that pertain to the open-hearth furnace?

Jan 1, 1939

By H. Hejny

Economy needs mineral raw materials in almost each sector of modern life. They can only be provided by mining activities. An increasing share of the total mining production will be by underground mining. The mineral deposits will be found at gradually greater depths, including all problems associated with them. It involves an increase in overburden pressure with subsequent rock stability problems and risks of structural collapse. There is a need for new and safe technologies for almost all parts of a modern mine. The mining industry faces a number of challenges which require technical solutions that encompass the entire network and include the economic, social and environmental issues. The industry needs a new image based on pioneering solutions and a modern structure that can exploit minerals at greater depths and promote both high productivity and safe working conditions. Funding has been secured from the European Commission for the I²Mine project. Work started in November, 2011. This initiative is designed to focus on the technological challenges that the mining industry is currently facing including the exploitation of ever deeper deposits and the aspiration for an invisible, safe, zero impact mine. The project comprises a consortium of 27 organisations from 10 European countries. I²Mine marks the start of a series of development activities aimed at realising the concept of an invisible, zero impact, deep mine. The extractive sector, still seen as being old fashioned and environmentally unfriendly, will show that mineral extraction and processing can be done in a highly innovative and sustainable manner with low impact underground and zero impact above ground. The concept of I²Mine is to develop innovative methods, technologies, machines and equipment necessary for the efficient exploitation of minerals and disposal of waste, all of which will be carried out underground. This will dramatically reduce the volume of surface transportation of both minerals and waste, minimising above ground installations and reducing the environmental impact. New eco-efficient technologies will be applied in order to make the entire mining process more efficient and environmentally sound. The concept is for an integrated mine, with the majority of the installations underground, and only the final product will be transported above ground to be shipped to the customer. Production waste will be treated and stored underground and gaseous emissions will be managed underground as far as practical. I²Mine will also focus on ideas and concepts that increase energy efficiency and decrease waste. The core of the project will be to develop breakthrough technologies for autonomous, highly selective, continuous mineral extraction processes and machinery based on new sensor technologies, face front separation as well as innovative concepts for mass flow management and transportation integrating state of the art technologies. The concept of an invisible, zero impact mine requires a refined process underground that selectively extracts the mineral thereby reducing waste. For this reason, improved extraction machines and near to face processing methods, including backfill procedures, need to be developed. These developments include rock mechanics and ground control solutions, incorporating health, safety and environmental issues.

Aug 1, 2013

By E. G. Bazeley

The paper reviews the scope, timing and financial impact of this significant project, which involves the supply and transportation of nearly 4 million tons per year of bituminous coal and lignite from sources in British Columbia. Alberta and Saskatchewan to Ontario Hydro's generating stations. The critical factors involved in the selection and utilization of these coals are discussed in relation to the three types of coal to be utilized initially. The paper then deals with each of the significant project elements to be undertaken by the various companies involved in the mining and movement of the coal, beginning with production at the mine through rail shipment to Thunder Bay, train-to-ship terminalling, shipment by lake vessel from there to the generating station, and finally blending the bituminous coal with United States coal prior to combustion. The review discusses the key features of the facilities involved in each case and the status and timing of the project elements , which are phased for the start of coal shipment by mid-1978. The paper concludes with some observations on the capability of the project to handle increased tonnage s and the challenges facing the movement in terms of quality , quantity and cost.

Jan 1, 1978

By L. Van Wyk, J. Fernandez, J. Suarez, L. J. Diaz, A. Uria, D. Breeuwer

"Ventilation is an essential component of any underground mine, playing a vital role in ensuring the health and safety of workers, and a mine’s continuous operation. At a time when mining companies are increasingly having to move to deeper underground operations in pursuit of high-grade ore-bodies, the search is on for more efficient ventilation systems that will allow mining to be carried out at even deeper levels whilst ensuring the protection of workers and the maximisation of productivity through temperature management and the lowering of energy costs. Mining companies today are looking for innovative ways to deliver new technologies and procedures to enhance their mine’s profitability. Energy consumption by mine ventilation systems is higher than ever due to stringent specifications of underground equipment (primarily combustion engine emissions), air quality standards and mining at deeper levels which all require more powerful ventilation systems. With energy costs associated with operating ventilation systems being a mine’s second-highest cost of production after labour, finding the optimal ventilation solution is critical to a mine’s performance. Proper fan design remains a major factor in reducing capital expenditures (CAPEX) and operational expenditures (OPEX), which means that there are compelling reasons for making use of comprehensive factory testing at full power before fans are dispatched to site to simulate the mine’s current and future design requirements, and thus verify the fan’s effectiveness in ‘real’ conditions.INTRODUCTION A primary mine fan is considered the heartbeat of the entire mine ventilation system, drawing fresh air from the surface and providing a safe environment for miners. A ventilation system’s lack of performance often leads to a reduction in acceptable air quality levels for underground working operations and can potentially have an adverse impact on production rates."

Jan 1, 2019