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"THE GOLD MINING REGION of Timmins - Val d'Or, astride the Ontario-Quebec border, has long suffered the effects of rising costs during the period when the U.S. price of gold was fixed at $35 per ounce. The federal government, through such assistance programs as that set up under the Emergency Gold Mining Assistance Act (E.G.M.A. ) in 1948, has subsidized the gold mining communities of Canada for a total of over $300 million to March 31, 1972. Of this, the Timmins - Val d'Or ""gold belt"" has received more than twothirds, almost $220 million. In spite of these continuous subsidies, only 12 gold mines are still producing in the Timmins - Val d'Or belt, whereas 71 mines have received subsidies for some period since 1948. The vital question is how the communities previously supported principally by the mining of gold will survive in the long run, as many of the older mines either are already depleted or are quickly becoming so. With the rising price of gold on the 'free market in recent months, prospects look a little brighter for the time being. Even with the increased official price of U.S. $38, which made the maximum government subsidized price about $48 per ounce, gold mines have not sold any gold to the government since January 1972 and some stopped doing so months before that. The populace of the region has not been enthusiastic about relocation nor about extensive retraining programs in the past and probably will not be in the future. So, when the remaining gold mines become depleted, the old problems of community depression will remain."

Jan 1, 1973

By R. Khettabi

The mechanical, thermal and bioproperties of titanium alloys allow their wide use in different industries. Compared to aluminum alloys, titanium alloys are very tough, making them that much more difficult to machine than aluminum alloys. Most studies conducted on these types of materials have mainly covered and made comparisons in terms of cutting speed, cutting force and mechanical properties. Recently however, their sustainability and environment parameters have begun to attract significant interest, and it has been found that machining processes generate particles that can be harmful for health and the environment. In this paper, particle emission is investigated during the turning of the titanium Ti6A14V and 6061-T6 aluminum alloys.

Jan 1, 2011

By F. H. Samuel, J. E. Gruzleski, S. Valtierra, H. W. Doty, F. J. Tavitas-Medrano

319-type cast Al-Si-Cu-Mg alloys are commercially important due to their popular use in automotive applications. Artificial aging heat treatments are commonly performed in these alloys to achieve precipitation hardening and, therefore, improve their mechanical properties. The present work was carried out to investigate the effect of conventional (at a constant temperature, as specified by the standard T6 heat treatment regime), and non-conventional multi-temperature and interrupted aging cycles on the hardness, tensile and impact properties of two 319-type alloys (with and without Sr+ Mg additions). The results show that certain multi-temperature aging cycles have a more favourable effect in improving some mechanical properties than conventional cycles.

Jan 1, 2006

By Gerry Roblesky

"IntroductionWestar Mining Ltd. is Canada's largest producer of metallurgical coal for the export market. It currently operates two mines, the Balmer Mine at Sparwood, British Columbia producing 6 000 000 tonnes per year and the Greenhills operation at Elkford, producing 2 100000 tonnes per year. Approximately 1600 people are employed between the two mines which operate independently but share common administrative services.Like most mining companies in Canada over the past three or four years, Westar has faced rising production costs along with flat or declining prices and demand for its products. In order to survive under these conditions it has become necessary to strive for decreased costs in any way possible. Over the past two years there has been a widespread introduction of microcomputers across the company. In order to satisfy increasing demand for accurate and pertinent information while at the same time increasing productivity, the microcomputer has become an invaluable tool.This paper describes some of the problems faced by a mine maintenance department in this operating climate and how they were solved with the help of a microcomputer. It also describes some of the problems that may be encountered both with equipment and people and recommends some ways that these might be minimized or avoided. Finally, an assessment of whether or not the move to microcomputers was a current and economical one, and a brief description of future plans and projects is given.The Maintenance OrganizationIn order to appreciate fully the role that microcomputers are playing within the Maintenance Department at Westar Mining, a little background on the organization and operating philosophies is in order. Most of the comments apply directly to the Balmer operations, however, the Greenhills operation is similar in concept.The mine maintenance organization operates on a fleet based concept with these departments reporting to the maintenance superintendent: haulage trucks, shovels and drills, loaders and Caterpillar equipment, maintenance services, and rebuild services.Each of these departments is headed by an assistant superintendent and is responsible for all maintenance on the equipment on the respective fleet. Shift foreman, planners, specialists and clerical staff are assigned to each fleet. A central engineering and administrative group consisting of one engineer and three clerical positions is responsible for maintenance engineering and centralized administrative services"

Jan 1, 1988

By F. Khomamizadeh

In this study, deep cryogenic treatment was applied to A319 cast aluminum samples. Although the cryogenic treatment didn't have any significant effect on mechanical properties of the well degassed and fluxed samples, but the tensile strength of the samples containing a considerable amount of gas and shrinkage defects was improved surprisingly, This improvement was attributed to the strengthening of the a-aluminum matrix which slows down the propagation of the existing defects. There was no significant increase in the hardness after cryogenic treatment, The abrasion resistance of the alloy was improved after cryogenic treatment, by developing a homogeneous protector shield, composed of abrasive grains penetrated into the soft aluminum matrix and kept tight.

Jan 1, 2005

By N. J. Duncan

"Coal mining, whether surface or underground, has hazards that make it unique in the field of industrial safety and health. The often soft, faulted and folded sedimentary strata make wall or roof movement a risk to the safe and economic removal of the coal, while the extraction and handling of coal may create an explosion hazard even in surface operations, In Canada, these problems are compounded by the situation of the coal fields which range from deep undersea deposits in Nova Scotia to steeply pitching thick coal seams high in the Rocky Mountains. Climate too can create its own problems, particularly the effect of metals of minus 40°C temperatures, as crumpled dragline booms at prairie strip mines witness. Because of the difficult and sometimes hazardous conditions, Canada's underground colliery managers, in common with those of other Commonwealth coal-producing countries, must have a government ""certificate of competency"" before being appointed as mine managers. Certification of assistant managers (""under-managers"") and foremen (""fire-bosses"") is also a legal requirement for all of Canada's underground collieries, while the province of Alberta requires certification of surface management personnel. Electricians and mechanics who install and maintain the specially designed equipment underground and in hazardous areas of surface mines and processing plants, and mine surveyors who ensure accuracy of the location of underground workings, must also hold government certificates of competency. The requisites for all certification include a minimum work experience and knowledge of coal mining technology and mine safety and health legislation. Despite recognition of the hazards and increasing knowledge of methods of preventing explosions of flammable gas and coal dust in Canada's underground mines, there have been several disastrous explosions such as those at Springhill Colliery in Nova Scotia in 1891 with the loss of 125 lives, at Hillcrest Colliery in Alberta in 1914 with 189 dead, and more recently · explosions and fires in No. 20 and No. 26 Collieries in Cape Breton. Preventing explosions has required developing optimal ventilation techniques, reducing ignition potential, suppressing ignition at source, draining flammable gas before it can enter the air courses, and preventing, or sealing off, autogenous heatings with their associated carbon monoxide or explosion dangers."

Jan 1, 1985

By B. Wasmund, M. Parravani, M. Jastrzebski, Z. Coull

"One of the main drivers of overall profitability of pyrometallurgical vessels is refractory lining campaign life. Increased economic pressure to improve vessel life requires innovative solutions to the problem of refractory cooling. Hatch has recently developed a high-intensity, waterless cooling system that bridges the performance gap between external shell cooling and internal water-cooled copper elements. External shell cooling has a limited effectiveness in protecting the refractory lining, because it is thermally insulated from the hotface of the lining by its thickness. This situation does not improve until the lining itself has become worn near the end of the campaign. The patented technology developed by Hatch overcomes this problem by positioning high-velocity air-cooling channels within the lining, closer to the hotface where the cooling benefits can be realized throughout the entire duration of the campaign. The current paper presents the development and application of Internal Air Cooling technology as well as results from the pilot campaign in an operating commercial vessel. Various adaptations for this novel, cost-effective and inherently safe system are also discussed."

Jan 1, 2015

By Christopher A. Jacobs

Project managers aim to maximise the NPV of their projects, but don't always appreciate the relationship between mine throughput, project value and the discount rate being used to evaluate their projects. Rate of production or throughput is perhaps one of the most crucial decisions a project manager must make, but if this choice is made arbitrarily, much effort may be spent on a feasibility study that does not optimise project value. The timing of the study in relation to the stage of exploration is examined and simple techniques are presented that project engineers and managers can use to home in on a production rate which will give their project the greatest chance of success.

May 1, 2006

By W. S. McDonald

PRACTICALLY all dusts derived from organic matter are explosive and instances are recorded of explosions-some of them extremely violent-having occurred in grain elevators and flour mills. While a discussion of the explosibility of dusts in general, doubtless, would be of more than academic value, it will be of greater interest, on this occasion, to consider various phases of the problems connected with the hazards arising from coal dust. Extensive and valuable research has been carried out during the past few decades on the subject of coal-dust explosions and a great part of this work has been concerned with the preventive effect of stone or other incombustible dusts. Four men have been outstanding in this very substantial achievement. The first is Dr. W. Galloway, who succeeded in demonstrating by experiments that one pound of coal dust mixed with 150 cu. ft. of air formed an explosive mixture. The next is Sir W. Garforth, who proved that stone dust is an effective preventive for coal-dust explosion. The third is G. Haon, and last but not least, L. G. Hill, both of whom laboured incessantly to produce a suitable stone-dust and a satisfactory method of application. Today, mining men all over the world are satisfied and convinced that stone dust, if properly applied, will prove effective in greatly minimizing, if not completely preventing, explosions of coal dust, as has been demonstrated in experimental mines, as well as in actual explosions, in practically every coal mining industry.

Jan 1, 1938

By V. G. Papangelakis, A. Dani

"Alkaline pressure oxidation, particularly in the presence of trona as additive, can be used to oxidize high carbonate refractory gold ores as it prevents the formation of CO2 in the autoclave. However, the presence of silica in the ore can lead to the encapsulation of pyrite due to the solubility of silica in alkaline solutions and its subsequent reprecipitation on the reacting pyrite surface, leading to the formation of a passive layer. This fundamental study investigates the chemical composition and thickness of the passive layer on a rotating pyrite disk using XPS and SEM, as a function of process conditions at 230°C, in an aqueous slurry containing silica sand, sodium carbonate and calcium carbonate under 100 psi of oxygen overpressure.INTRODUCTIONAlkaline pressure oxidation (POX) has been used successfully to treat high carbonate refractory gold ores, which contain carbonates in addition to sulphides, most notably at Mercur and Goldstrike mines operated by Barrick Gold. There are several advantages to using alkaline POX over its acid counterpart, especially due to high carbonate content. First, it eliminates the production of CO2 in the autoclave without resorting to pre-acidification, which allows for high oxygen utilization. Second, alkaline POX suppresses the formation of elemental sulphur and intermediate sulphur oxyanions (such as thiosulphates and dithionates), which reduce gold recovery. Third, the use of sodium hydroxide or salts prevents the formation of anhydrite scale by forming soluble sodium sulphate. Other advantages are the use of cheaper materials of construction and the formation of non-acidic residue that do not require further treatment prior to cyanidation (Thomas, 2005).Sodium carbonate in particular is a promising reagent for alkaline POX because it was shown to significantly accelerate the kinetics of pyrite oxidation by molecular oxygen, when compared to other reagents such as sodium hydroxide, sodium borate and calcium hydroxide. This has been attributed to the following factors: a) the faster oxidation kinetics of Fe2+-CO3 complexes compared to Fe2+ oxidation, b) the buffering effect of carbonate ions on the acidic pyrite surface, and c) the increased solubility of oxidizing Fe(III) species due to carbonate complexation (Caldeira, 2010)."

Jan 1, 2012

By A. Brown

The swift decline of coal during the period of unprecedented expansion in the Canadian economy is a phenomenon deserving careful examination, because the underlying forces contributing to this decline may have broader implications in our national economy. At the present level of technology, coal is more difficult to process, transport and utilize than liquid and gaseous fuels. Fundamentally, it is a matter of limitation in technique. Because coal is a vast store-house of energy in Canada, the reduction of these limitations is in the long-term national interest.

Jan 1, 1967

By Michael Zurowski

This paper traces the history of International Mogul's assessment program on the Lake Ainslie barite-fluorite deposits of Cape Breton Island. The geology of the area is outlined, and the main vein systems described. The geophysical and geochemical exploration techniques employed are explained, the metallurgy of the ore is covered, and the market prices and economics of operation are described.

Jan 1, 1972

By W. Keith Buck

This paper defines the discipline of mineral economics. By example, it describes the application of the tools of economic analysis to mineral problems - to problems in the areas of: mineral resource analysis and forecasting, mineral industry activity from exploration to distribution and marketing, mineral commodity analysis, and mineral policy analysis and policy formulation - all in a regional, national or international context.

Jan 1, 1972

By Dave Ecobichon, Éric Côté, Simon Nickson, Michel Leclerc

The feasibility assessment of a mineral deposit requires the construction of a geo mechanical model of rock mass properties, for the purpose of preliminary mine design. The Noranda Technology Centre has been involved in the development of geomechanical models for several mineral deposits at the feasibility stage. Each model is constructed through intact rock testing, geotechnical core logging, geotechnical mapping and rock mass classification. Rock mechanics principles are used to develop conceptual stope designs and propose possible mining sequences. This methodology is applicable to both new mining projects and to the development of new areas within anoperating mine. This paper explains how the geomechanical model is developed and reviews its application to several case studies.

Jan 1, 1996

By R. J. Twigg, S. D. Chang

"The production of heavy water, the moderator in a CANDU reactor, is examined following a flow sheet of a typical Canadian plant. The process involves the extraction and concentration of deuterium from natural water through a chemical exchange mechanism with hydrogen sulphide. Consequently, corrosion problems associated with sour environments – the use of hydrogen sulphide - are an everyday problem and have led to the development of a highly refined materials selection and testing program to prevent equipment from failing prematurely.IntroductionHeavy water is a naturally occurring compound in ordinary water and is formed from the combination of two deuterium atoms and one atom of oxygen. Deuterium is a heavy hydrogen atom which has a nucleus of on e proton and one neutron. Hence, heavy water is a combination of heavy hydrogen and oxygen and is chemically known as deuterium oxide. It looks and tastes like ordinary water but it freezes at 3.8°C and boils at 101.4°C. The molecular weight of heavy water is 20 as compared to 18 for ordinary water; the density of heavy water is ten per cent greater than that of ordinary water.Although heavy water and ordinary water exhibit only small differences in their chemical and physical properties, there are large differences in their nuclear properties, the most important of which is the neutron moderating ratio, used to measure the ratio o f the slowing down power to the neutron capture characteristics. For heavy water the ratio is 21000 and for ordinary water it is 50. This high moderating ratio is essential for achieving a high neutron economy. Heavy water is, therefore, chosen as the moderating and heat transport fluid in the CANDU reactor."

Jan 1, 1983

By J. Jin, J. D. Miller

"Bubble attachment at hydrophobic surfaces is of critical importance in the flotation recovery of mineral resources and fundamental experimental results have been reported in the literature describing the details of film thinning, rupture, and displacement. Now, for the first time, bubble attachment phenomena are examined using Molecular Dynamics Simulations (MDS). The simulation involves a nitrogen bubble containing 906 nitrogen molecules in a water phase with 74,000 water molecules at the hydrophobic molybdenite (001) surface. During the simulation period of 1 ns, film rupture occurs and the nitrogen bubble attaches to the molybdenite (001) surface, resulting in a contact angle of about 90o. In contrast, the film is stable at the hydrophilic quartz (001) surface and the bubble does not attach. Contact angles, determined from MD simulation after stabilization of the three phase line of contact, are reported and these results agree well with experimental and MDS sessile drop results. In this way, film stability and bubble attachment are described with respect to interfacial water structure for surfaces of different polarity. For example, the interfacial water molecules for the hydrophobic molybdenite (001) surface have relatively weak interactions with the surface when compared to the hydrophilic quartz (001) surface, as revealed bythe presence of a 3 A water exclusion zone at the molybdenite/water interface. INTRODUCTIONAttachment of air bubbles to mineral particles is of fundamental importance in understanding flotation separation phenomena. It is well known that attachment of an air bubble at a hydrophobic surface includes film thinning, film rupture, and film displacement (Somasundaran, 2006; Wilson, Adlard, Cooke, & Poole, 2000). Experimental techniques, such as high speed video, can catch the process of bubble attachment at a mineral surface (Drelich & Miller, 2012; Niecikowska, Krasowska, Ralston, & Malysa, 2012). However, molecular scale information to examine the phenomena has not yet been reported."

Jan 1, 2016

By H. Lorenzen, D. Buyze

"Magnesium-bearing salts occur in the Zechstein Basin in the north eastern part of the Netherlands at a depth of 1500m to 2500 m.Exploration results justified the exploitation of these salts by means of solution mining for the production of refractory grade magnesium- oxide. This paper discusses design criteria, operation parameters, and methods used for magnesium chloride solution mining by Noordelijke Zoutwinning B. V. (NOZO), an operating company of Billiton International Metals B. V.A unique variation of widely used solution mining techniques has been developed for mining the complex Veendam salt deposit. NOZO extracts salt through deviated wells with a set of parallel, suspended tubings. Cavern fluid pressure is maintained close to that of overburden rock. These special design features provide an answer for the complex characteristics of the minerals, halite, carnallite, bischofite and kieserite, from which a solution rich in magnesium is generated. Dissolution chemistry and rock mechanical behaviour of these salts are unlike those of rock salt. Throughout a few years, NOZO demonstrated adequate process control while they continue improving the operation.IntroductionBilliton, a wholly owned company of the Royal Dutch /Shell Group of Companies, is active in metal exploration, mining, processing, and trading, mainly in the non-ferrous sector.Since 1972 Billiton has been active with solution mining magnesium salts in the northeastern part of the Netherlands, in the Province of Groningen, near the city of Veendam . Solution mining techniques were developed in conjunction with the ""Koninklijke/Shell Laboratorium Amsterdam"" (KSLA) and the ""Koninklijke/Shell Exploration and Production Laboratorium"" (KSEPL), Rijswijk. The company's objective is to produce magnesia sinter (MgO) from magnesium-chloride brine (MgClz) and de-carbonated dolomite (CaO.MgO). The magnesia produced serves as base material for the manufacturing of refractory bricks, used for furnace linings in the steel industry."

Jan 1, 1986

By Shintaro Takamiya, Kazunari Yoshida

"Recently, small sized micro-needles for medical are required more frequently by patients. The biggest reason is that it presents great burden on the patients, due to the size of the needle injection. People need to use a very small needle to lower the pain, but the downfall is that it makes them more expensive due to their complicated manufacturing method. Therefore, we need to fabricate a needle by wire-drawing to decrease its price. Tube-drawing is beneficial for its production value; however, in conventional tube-drawing it is difficult of control the wall thickness of the tube and makes it 1mmor lower in diameter. That is why, we propose fluid-mandrel drawing for new tube drawing. This method allows fabrication of a fine tube by using the pressure of the fluid in the tube. In this research, the goal is the fabrication of a fine tube by fluid-mandrel drawing and its evaluation. Finally, the fabrication of a fine tube by fluid-mandrel drawing was conducted and in result a tube with a diameter of 0.2mm, high strength and thin wall and fine inner surface was drawn, which can be used as a lesser pain micro-needle.INTRODUCTIONThe main manufacturing method of the current medical needles is roll forming. With this method, it is difficult to make a tube with a diameter lower than 1mm. Deep drawing has been proposed and used as method to further reduce the diameter, but this method is costly and the injection needle obtained by this method is several times more expensive.Therefore, we need to obtain a fine medical needle by drawing process that can be mass-produced and inexpensively manufactured. However, with the conventional drawing process, it is not possible to obtain a syringe needle with a reduced diameter easily, that is why, a fluid-mandrel drawing has been proposed which can reduce the diameter without damaging the inner surface. The methodology of the method is, a fluid is filled in the sealed tube and the pressure inside the tube during drawing is responsible for the good inner surface and wall thickness. It is also expected that the fluid can be easily discarded and that the tube can be manufactured on a long scale."

Jan 1, 2017

By A S. Leitch

This paper is based on the accident prevention pro-gram carried out in the coal mines of Alberta. It defines the role of the Alberta Mines Branch and of The Work-men's Compensation Board, and relates how a safety pro-gram was initiated. The formation of the Alberta Class 1 Mining Safety Council is also described. The responsibilities of both management and the individual worker are then outlined, and the main features of a successful accident prevention program are delineated. T HE purpose of this paper is not to repeat generalities and platitudes about industrial safety, but rather to relate the experience of Alberta coal mines during the past number of years in their efforts to keep accidents to a minimum. It has been learned from experience that many basic principles are as sound today as they were 20 years ago. How-ever the complexities of modern mining methods and the modern man or miner have created problems that did not exist then.

Jan 1, 1964

By A. B. Rossetti

"THE MISSION TO Offshore Scotland was in my opinion a very worthwhile venture, as it indicated the scope of the offshore oil and gas business and how we might exploit it to the fullest here in Nova Scotia - if our offshore fields eventually become producing fields. The writer was able to attend a considerable number of lectures and as a result gained some valuable know-how on the engineering design, financing and operation of the North Sea oil industry. There are many new fields of technology that had to be developed to overcome the North Sea's hostile environment and a great deal of the same technology will have to be developed to win oil and gas from our continental shelf. The visit left me with several impressions, which in the main are:(1) The high order of investment required to develop offshore oil. The investment ranges from 10 to 20 times that required for a similar output on land. Each barrel of oil costs on the average of about $2,- 500 per barrel per day.(2) Because of the high investments required, before the first oil is produced the field must be brought into production at the earliest possible date and initial lead time from decision to production is less than four years. In the British Petroleum field, working at a depth of 450 feet will require an investment of $900,000,000 to develop a production of 400,000 bbl per day. (3) The size and complexity of equipment required is beyond anything ever imagined. Problems which must be overcome are such factors as water depth, wind velocities, wave height, wave period, long periods of darkness, low temperatures, distance from land, and fog."

Jan 1, 1973