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"The QEMSCAN system is the third generation of automated mineral analysis systems that began with the QEM*SEM at CSIRO 30 years ago (Butcher et al. 2000). It is now a successful commercial instrument with 39 instruments in operation around the world. Back Scattered Electrons (BSE) and Energy Dispersive (EDS) X-Ray spectra are used to create digital mineral images with mineral identification occurring online. Low-count EDS spectra are used preferentially to BSE brightness, allowing minerals to be accurately identified by chemical composition. Individual minerals or groups of similar compositions are identified by comparison to a comprehensive mineral database incorporated into the QEMSCAN software. Optical mineralogy and Scanning Electron Microscopy is a metallurgists’ tool for determining the ore process mineralogy and delivering a better flowsheet. These techniques have limitations, provide limited information and sometimes fail to provide representative information. In contrast, QEMSCAN provides information on the nature and occurrence of all mineral species present plus the liberation characteristics, looking at thousands of particles in the sample presented. Some of the data presented includes:• Particle and grain sizes• Dominant mineral species• Particle shape• Calculated metal content• Density• Deportment of elements of interest between the mineral phases• Quantitative mineralogy• Mineral associations, locking and liberation• Textural relationships (particle images)It can also be used on concentrates, polished sections or drill core. This is a significant improvement in ore characterisation providing lithology, mineralogy, liberation, ore grade and porosity from a sample. Theoretical grade-recovery curves can be created to be mineralogically limited from QEMSCAN analysis which, when compared with metallurgical results, are valuable in evaluating whether liberation or chemical selectivity is driving flotation performance. A number of case study examples are given where the QEMSCAN had a significant bearing on future project development at an early stage of exploration and mine development."

Jan 1, 2012

By I. C. Brown

Introduction Many tables of nomenclature for igneous rocks have been introduced from time to time, and each has its strong proponents. As a result, any discussion of igneous? rocks is apt to prove confusing unless the names used for these rocks are defined. This ?became so obvious to a discussion group, formed by the members of the Geological Survey of Canada in 1948, that an attempt was made to establish a scheme of nomenclature that could be used by any member mapping anywhere in Canada. The writer was asked to co-ordinate the ideas presented by individuals in the discussion group, to arrange them in tabular form, and, later, to distribute copies of the resultant table to Canadian universities, provincial geological surveys, and some other geological discussion groups. Many useful suggestions and criticisms were received, were studied ?by members? of the original group, and, so far as practicable, were incorporated in the scheme of nomenclature. The result is the table presented here. This nomenclature of igneous rocks is at present being used by most members of the Geological Survey of Canada who are working with igneous rocks, and by some Canadian universities. We hope it will be found useful and be more widely accepted. With this idea in mind, certain principles were adopted in drawing up the nomenclature.

Jan 1, 1952

By M. B. McClenaghan

"Abstract- The Ontario Geological Survey completed a regional till sampling project between 1984 and 1988 in the Black River Matheson (BRiM) area of northeastern Ontario. The project was designed to aid mineral exploration in the area by documenting the Quatemary stratigraphy and by providing a database of till geochemistry. This paper summarizes the results from the sonic overburden drilling component of the BRiM project carried out in areas of thick drift (> 5 m). Results from till sampling in areas of thinner drift (<5 m) have been presented in a separate paper. Approximately 1100 till samples were collected from 225 sonic drill holes. For each sample, the non-magnetic heavy mineral (> 3.3 S.G.) and fine (-250 mesh) till fractions were analyzed geochemically and visible gold grains were recovered by panning.Gold and other multielement geochemical data were plotted using proportional symbols to high­ light anomalous areas and to demonstrate how to evaluate and interpret a very large geochemical dataset. Thresholds for identifying anomalous concentrations of Au in till samples, defined using the 95th percentile, are 1500 ppb and 12 ppb for the heavy mineral and fine fractions, respectively. The heavy mineral fraction of older tills and to a lesser extent, Matheson Till, display a number of significant gold anomalies in the study area, which in a few cases, are associated with base metal anomalies. The vertical position of gold anomalies in Matheson and older tills varies from directly on bedrock to several meters above the bedrock surface and can provide information of relative ice transport distances."

Jan 1, 1994

By Haipeng Li, Jacob Masliyah, Barun Gorain, Jian Huang, Qingxia Liu, Zhenghe Xu, AuTec Innovative Extractive Solutions Ltd.

"Froth flotation is widely used to selectively separate one or more minerals from an ore over a wide range of particle sizes with high efficiency. Bubble–particle attachment is one of the most critical steps in flotation. The objective of this project is to demonstrate the need for an innovative dual bubble generator to improve flotation efficiency. This dual bubble generator was designed to generate two different sizes (micron size and typical flotation size) bubbles. The micron size bubbles generated on the crevices of particle surfaces in venturi type of cavitation tubes enhanced the attachment of fine particles to the bubbles in conventional flotation systems. They also acted as a secondary collector, which has the potential to reduce operation cost and improve flotation recovery. The dual bubble generator was evaluated for a double refractory gold ore with 3g/t Au, 1.5 wt% TCM (total carbonaceous matter) and 0.7 wt% sulfides. The results were compared with those obtained using a commercial bubble generator. Compared with the commercial bubble generator, the dual bubble generator showed not only a higher gold recovery, but also an improved separation efficiency, demonstrating the potential of dual bubble generator in fine particle flotation.INTRODUCTIONFroth flotation has been widely used in mineral processing and waste water treatment. However, flotation has been proven inefficient for fine particle recovery although it becomes increasingly inevitable to process fine particles with the depletion of easy processing ores. The critical problem of fine particle flotation is the low attachment of fine particles to flotation size bubbles due to their low collision rate. Based on a commonly acceptable flotation model given by R =F*[Pc*Pa*(1-Pd)], the probability of bubble–particle collision (Pc), attachment (Pa) and particles detachment from air bubbles (Pd) collectively determines fine particle recovery (R) (Yoon and Luttrell, 1986). Since Pc = (3Dp/Db) where Dp and Db are diameters of particles and bubbles, respectively, bubble size and particle size impact the bubble-particle collision in opposite directions. It is evident that the probability of bubble–particle collision decreases with decreasing the size of particles, leading to a low recovery of fine particles. In this case, reducing the bubble size and/or increasing the apparent size of particles by fine particle aggregation are clear means to improve fine particle recovery."

Jan 1, 2016

By A. M. A. Mohamed, F. H. Samuel, S. Valtierra, H. W. Doty, A. M. Samuel

"The influence of Fe, Mn, Cu and Mg alloying additions, Sr modification and grain refinement on the microstructure of as-cast and solution heat-treated Al-10.8% Si alloys was investigated using optical microscopy and EPMA techniques. The results showed that the modification effect of Sr diminished with increasing Cu and Mg additions, due to Sr-Cu-Mg interactions. Strontium caused segregation of AlzCu in areas away from eutectic Si regions, and altered the precipitation sequence of the a-Ah5(Fe,Mn)3Siz iron intermetallic from post-dendritic to pre-dendritic, with the phase observed within the a-Al dendrites. Depending upon the alloy Fe and Mn content, a coarser variation (""sludge"") of the a-Fe phase occurred, in the form of polyhedral shaped particles. The AhCu phase dissolved almost completely during solution heat treatment, while Al5Cu2Mg8Si6, sludge, and a-Aln(Fe,Mn)3Siz phases persisted in all alloys, particularly at high Mg and Fe levels. The f3-Al5(Fe,Mn)Si phase dissolved partially in Sr-modified alloys, the dissolution becoming more pronounced after solution heat treatment."

Jan 1, 2006

By George S. Martin, Michael D. Winship

"Placer Dome Inc. is the operator of the Musselwhite project located 100km north of Pickle Lake, Ontario. J.S. Redpath Limited was contracted to conduct an underground exploration program using shaft access.During the winter of1988, the shaft collar was established in 16 metres of water bearing sand and till overburden. This paper will illustrates the engineering techniques used to overcome the obstacles to installing a shaft collar in deep overburden. Specialized dewatering and piling procedures were employed.INTRODUCTIONHarold and Allan Musselwhite discovered gold in the Opapimiskan Lake area, north of Pickle Lake, in 1962. The prospectors were grubstaked by ten companies in 1973.A diamond drill program was initiated shortly thereafter.In 1983an underground ramp exploration program was carried out on the West Anticline portion of the property. The program was unsuccessful in establishing an ore reserve so surface exploration continued. In 1986the ""T"" zone was discovered. Further surface drilling was done and an over-all drill-indicated reserve of 6 million tonnes at 7 grams per tonne was outlined. The gold mineralization occurs in several vertical tabular deposits within the iron formation. In late 1987the joint venture partnership, now consisting of Placer Dome Inc., Inco Gold Co., Corona Corporation and Esso Minerals Canada, contracted J.S. Redpath Limited to conduct an underground exploration program on the ""T"" Zone.The scope of work for the project was to: 1. establish a 45 km winter road in 1988 and 1989;"

Jan 1, 1989

By J. Malone, D. Loth, J. Palmer

WMC Resources&apos; Kalgoorlie Nickel Smelter was commissioned in 1972 at a design capacity of 30,000 tpa of contained Nickel in matte. A series of upgrades and progressive improvements have resulted in a design capacity increase to 110,000 tpa of contained Nickel in matte. The smelter sources nickel-in-concentrate from three Mine / Concentrators and supplies nickel-in-matte to WMC&apos;s Nickel Refinery and export customers. The Flash Furnace was last rebuilt in 1999, and is over halfway through the 10-year campaign target. The many modifications over the previous campaigns, including the Integrated Flash Furnace, are reviewed. Recent operation of the smelter and the development of the process during the current campaign are detailed herein. An overview of key interfaces with the Nickel Business Unit Concentrators and Refinery operations is provided.

Jan 1, 2005

By S. Mathieu, R. Mennillod-Blondin, P. Cousin, N. Valle, H. Bouzahzah, P. Marion

The gold deposit of the Lapa mine has a complex mineralogical gold state with coarse and fine native gold, aurostibite and submicroscopic gold within arsenopyrite. A specific mineralogical characterization of the refractory fraction was conducted combining various techniques such as optical microscopy, electron microscopy, electron microprobe and secondary ion mass spectrometry. In parallel, the mineral processing behaviour and the recovery of the refractory gold were studied by pressure oxidation and cyanide leaching. This paper presents the mineralogical methodology developed to characterize the refractory gold distribution within arsenopyrite. These results are presented and interpreted in order to plot gold recovery versus sulphide oxidation. The comparison of the metallurgical behaviour yields predicted from the mineralogical data and the one calculated from leaching tests shows a good agreement and allows mineralogical explanations of the gold metallurgical behaviour.

Jan 1, 2011

By J. Desroches, J. Burghardt, N. Whitney, B. Lecampion, A. Surdi, M. Houston, S. Stanchits

There is accepted evidence that multistage fracturing of horizontal wells in shale reservoirs results in significant production variation from perforation cluster to perforation cluster. In fact, only a fraction of the perforation clusters seem to contribute to production in many shale gas and shale oil plays. In many cases, the orientation of the lateral section of these wells is determined by lease boundaries rather than principal stress directions, and these often do not coincide. When horizontal wells are misaligned from the far-field principal stress directions, the fracture must reorient from the near-wellbore principal stress directions, which are aligned with the wellbore, to the far-field principal stress directions. The primary objective of this study is to learn how various completion designs influence the near-wellbore fracture geometry when such a misalignment exists. A secondary objective is to understand the influence of rock fabric features, such as mineralized natural fractures, on this reorientation process. To understand these effects, eight laboratory hydraulic fracturing tests were conducted using a true triaxial vessel with 914 mm × 762 mm × 762 mm samples of Niobrara shale. Several different completion designs were studied, including the use of fracture initiation slots with several different orientations and the use of perforations selectively located to encourage a smooth transition from the near- to far-wellbore region. The tests were carefully scaled as accurately as possible to provide insight into the field near-wellbore phenomena. Pressure and fluid flux at the wellbore, deformation of the block, acoustic velocity, and induced acoustic emissions were acquired during the tests. Additionally, sized particles were also injected to gauge the fracture width away from the wellbore. After the test, the blocks were dismantled, and the fracture geometry was mapped in 3D. These measurements allow one to clearly differentiate the fracture initiation and the breakdown—meaning the peak pressure—to be clearly differentiated; the fracture was already well developed when the maximum pressure was reached. The study reveals non-negligible tortuosity and aperture restriction in the near-wellbore region. In the field, this would translate to high treating pressures, uneven proppant distribution, and possibly near-wellbore screenouts. The test results show that, of the configurations tested, the best approach is to use deep slots that are aligned with the far-field principal stress directions. The oriented perforation design did not achieve the simple, smooth transition that was hoped for, and instead produced multiple competing near-wellbore fractures and considerable tortuosity. The study also demonstrated that the presence of planes of weakness, such as mineralized natural fractures, near the slot tip can result in poor near-wellbore fracture geometries, even for the best completion configuration. We conclude from these tests that the misalignment of the well with a principal stress direction creates near-wellbore complexity that, in turn, creates uncertainty in proppant distribution and, therefore, production; proppant might avoid up to a half of the created fracture. Regardless of the wellbore orientation, this uncertainty is further increased by the presence of mineralized features in the rock fabric that can strongly alter or stop the growth of the hydraulic fracture. Preventing those effects by changing the completion alone proves difficult, and new strategies are required to ensure a reliable stimulation of shales.

Jan 1, 2015

By F J. Kelly

A chemical process, based on laboratory investigations, is proposed for the production of high-purity niobium oxide from a pyrochlore-perovsk1te flotation concentrate produced from ore obtained at the Oka, Quebec property of Columbium Mining Products Limited. The method developed included the decomposition and dissolution of the flotation concentrate with hot, concentrated sulphuric acid. The dissolved niobium was purified and concentrated by a solvent extraction step, using methyl isobutyl ketone as the extractant. The niobium was recovered from the extractant with ammonium fluoride solution from which niobium oxide was precipitated with ammonia. Finally, the filtered and washed precipitate was calcined. Ninety-six per cent of the niobium was recovered in a product analysing 99.9 per cent Nzo.. The reagent cost was in the range of $1.00 to $1.25 per pound of niobium recovered. Introduction OVER the past few years, Columbium Mining Products Limited has been engaged in the development of a niobium-bearing mineral deposit in the vicinity of Oka, Quebec. One phase of this program resulted in a flotation process capable of producing concentrates containing up to 50 per cent Nb205? Flotation pilot-plant

Jan 1, 1965

By C. Jay Hodgson, P. J. MacGeehan, T. Sanders

"The orebodies of the Campbell and Dickenson mines are localized within an anomalously fissile and deformed zone that transects the eastern margin of a dominantly mafic volcanic complex close to its contact with a synchronously formed sedimentary basin containing clastic and chemical sedimentary rocks. The ore zones are mainly quartz-carbonate fissure veins and siliceous replacement zones formed during deformation and metamorphism, although there are some syn-volcanic exhalative ore zones in the mines. On a regional scale, the volcanic rocks have been affected by syn-volcanic spilitic alteration which has involved the leaching of Fe, Mg, Au and As from, and the addition of Na and variable amounts of Si to bleached zones enveloping primary permeable structures in the rocks. The leached constituents were deposited on the contemporaneous sea floor as iron-rich chemical sedimentary rocks. Although this alteration is not closely related, spatially, to the ore zones, it is characteristic of the general environment, and may serve to distinguish gold-prospective from gold-barren areas on a mining-camp scale.Closely associated spatially with gold deposits is a zone of feldspar-destructive alteration within which the volcanic rocks are characteristically feldspar-free, enriched in As, Au and to a variable degree in Si, and depleted in Na, Ca and to a variable degree in Mg, Fe and K. The alteration zone is also characterized by abundant, variably transposed, small quartz-dolomite to ferrodolomite veinlets formed during deformation and metamorphism, and includes, but extends outside of, the anomalously fissile zone hosting the orebodies. The alteration zone is interpreted to have formed syn-volcanically within the upper part of a major submarine hydrothermal discharge zone."

Jan 1, 1982

By E. Quaquero

This article reports on the current state of an ongoing research project which is aimed at implementing intelligent models for hardly predictable hazard scenarios identification in construction sites. As past evidences showed that no programmatic action can deal with the unpredictable nature of many risk dynamics, we tried to survey on how the current approach for safety management in the construction industry could be improved. In our previous research the use of Bayesian networks elicited from subjective knowledge were preliminarily tested. Those networks might be meant as a reliable knowledge map about accident dynamics and they showed that a relevant ratio of occurrences fall in ?hardly predictable hazards? class, which cannot be warded off by programmatic safety measures. This paper reports the second outcome of our research project, which focused on the development of first elementary fragments, regarding the occurrence of a possible ?hardly predictable scenario?. Instead of experts? contributions (who, over their carrier, seldom incurred in accidents), we used ?legal cases? as an accurate source of information. They suggested which categories of ?hidden hazard scenarios? are more likely to happen. We found that the most frequent hidden hazard scenarios are linked to operator?s negligence and abnormal behavior, e.g. irregular removal of scaffolding?s components, unprotected openings, improper use of PPE, etc. Every pattern determined by legal cases has been formalized by a fragment (i.e. elementary network) of the overall Bayesian network. Finally, all the elementary networks were integrated into a comprehensive intelligent tool for realtime hardly predictable hazards prevention. The final setup, asked for interfacing these intelligent models to a low-level sensor network and used to feed them with inputs about the current state of the context, is discussed too.

Aug 1, 2013

By T. Alan O'Hara

"Annual mining revenue can be computed by formulae relating metal prices, smelting schedules, concentrate grade and recovery to known ore grade and an assessment of core samples. Operating costs at different daily tonnages are related to orebody shape, mining method, milling process and general plant services. Capital costs are related to sizing of mining equipment, mine development, plant-site topography, climate and accessibility, plant services and personnel housing. IntroductionA crude guide to the average 1978 cost of mine projects is shown in Figure 1, but the costs of many mine projects have differed widely from the graphed average costs of $800,000 T0.6 for underground mine/mill projects and $400,000 T 0.6 for low-grade open-pit mine/mill projects.High mine project costs and high operating costs are characteristic of open-pit mines with high stripping ratios, underground mines with thin orebodies, mills with complex metallurgy, and projects located in isolated regions with severe climate, mountainous topography, and lacking access to existing roads, towns and electric power. When none of these adverse conditions prevailed, the mine project cost was typically much less than the graphed average cost. Virtually all the conditions likely to cause high capital and operating costs are known from knowledge of the local topography, climate or accessibility, or can be assessed by tests on core samples, as soon as the orebody has been outlined by drilling .A more accurate estimate of over-all project capital cost and operating cost can be made from a summation of items of cost after judging the effect of specific local conditions on each item of capital and operating cost. This paper offers guides in judging the effect of local conditions on the sizing and 1978 cost of specific items of capital cost and operating cost and operating cost of mine projects. When the specific items of capital cost and operating cost are totaled and measured against expected net revenue and taxes over the life of the mine using the net-present-value or discount-cash-flow methods, the result should show whether the mine project development is clearly feasible, doubtfully feasible or clearly uneconomic. If the development of the mine project is clearly feasible, or probably feasible, a detailed feasibility study by experienced consulting engineers should be commissioned before any financial commitments are made; but if project development appears to be uneconomic, the time and cost of a detailed feasibility study is not warranted."

Jan 1, 1980

By Paul Guliov

Preliminary investigations of stone resources were conducted in the La Range, Johnson Lake-Pelican Narrows-Deschambault Lake and Creighton-Amisk Lake regions of Saskatchewan. The work identified a rich variety of accessible, attractive and technically promising stone resources. Ordovician dolomites in various combinations of red, buff, yellow, grey and purple are very dense and take a very good polish. These are classified as marbles in the industry and some rival the famous marbles of Verona, Italy. A wide variety of attractive granites have been identified. Among these is a jade green stone (charnockite) and ornamental banded granites (gneisses). A dark greenish to black stone (amphibolite) with white and red veining resembles the well-known Verde Antique variety of Vermont and Italy and surpasses it aesthetically and in engineering properties. Some of these stones have been displayed at Canadian and United States expositions where they received an enthusiastic response from the international stone industry. More detailed evaluation and test quarrying of promising deposits are required. Such work could be rewarding to the industry as some stone varieties in the province have the potential for gaining international markets.

Jan 1, 2001

By T. Lux, H. -J. Krassnig, I. Filzwieser, E. Hecker, R. Degel, A. Filzwieser

Non-ferrous metals find their applications in smartphones, tablets and computers. These materials with their particular properties are the basis of our modern life. SMS group is well prepared for this huge market and for growing future challenges. A large contribution here is the new joint venture PolyMet Solutions that was founded by SMS group and Mettop, an Austrian engineering company, with the objective to develop new technical solutions for the primary copper production lines as well as for non-ferrous metals starting with the primary smelting of concentrate and ending with the electrolysis. PolyMet Solutions provides the process know-how whereas SMS group supplies the plants and equipment and Mettop the key components. SMS group and Mettop also cooperate in the field of tankhouse technology. Together with Montanwerke Brixlegg AG, Mettop has developed together with a parallel flow technology (METTOP-BRX Technology), allowing a current efficiency of above 98 % at a current density of 420 A/m², which is a milestone in copper electrolysis. For the secondary copper production route, SMS group and PolyMet Solutions developed an innovative refining furnace (PolyRefine) for the smelting and refining of copper scrap. The refined copper is directly charged to the Contirod line to produce copper rods and wires. The innovative cooling solutions of SMS and PolyMet Solutions come into play where furnaces have to stand the highest loads and stresses, for instance in areas of very high temperatures or temperature fluctuations, aggressive exhaust gases and slags, or at critical spots such as taphole areas. Custom-tailored cooling systems for furnace vessels make sure varying loads are compensated in a targeted and effective manner. The solutions include air cooling, spray cooling, cooling technologies with integrated copper elements such as CFM (Composite Furnace Modular) cooling systems, plate and finger coolers. The major innovation in the field of furnace cooling is the ILTEC (Ionic Liquid Cooling) Technology which paves the way for increased plant safety. This revolutionary, patented cooling technology is jointly marketed by Mettop and SMS group. It permits water-free cooling to be implemented and thus makes operation safe wherever it is applied. INTRODUCTION Non-ferrous metals or NF metals are changing the world. There is no modern industrial sector that can do without these valuable metals. Non-ferrous metals find their applications in smartphones, tablets and computers. These materials with their particular properties are the basis of our modern life. The importance of the non-ferrous metals market is reflected by two figures. In 2018, the production of non-ferrous metals was worth more than 237 billion Euros. This contrasts with 255 billion Euros of the value of iron and ferro- alloy production in the same year (International Organizing Comittee for the World Mining Congresses, 2018). Hence, the NF metal industry is almost as important as the iron and steel industry. SMS group is well prepared for this huge market and for growing future challenges. A large contribution here is the new joint venture PolyMet Solutions that was founded by SMS group and Mettop, an Austrian engineering company, with the objective to develop new technical solutions and to enhance customer value. The prices of nearly all metals have come under pressure during the past few years. Therefore, competitive technologies are regarded a crucial factor to achieve success in this critical market situation respectively to stabilize the market position.

Jan 1, 2019

By A. N. Shen

Fe3A1 intermetallics are potential inexpensive candidate for hot applications. In this project, torsion tests on hot-rolled and annealed Fe3A1 (Fe-15.5A1-5.8Cr-1.0Nb¬0.05C) were carried out over the ranges 750-950°C and 0.01~1s-1 . The experimental results showed that when peak stress op>90MPa (LogZ>16s-1 , Z: temperature-compensated strain rate), specimens cracked at randomly low strains. Optical microscopy exhibited original elongated grains and many grain boundary cracks associated with segregation. With op<40MPa (LogZ<16s-&apos;), specimens deformed with low random op but considerably high fracture strains; slowly propagating cracks may explain the reduced flow stress. Optical microscopy showed both elongated grains and equiaxed subgrains with some indications of geometric dynamic recrystallization (gDRX) and of static recrystallization (SRX). Compression tests gave higher stress with little effect of the preexisting cracks. The activation energy Quw of current material in satisfactory torsion and compression tests is about 10% higher than previously published. Fe3A1 has body-centered cubic structure in the experimental range, so it was compared with ferritic stainless steel 434C (Fe- 16.55Cr-0.96Mo-0.21Ni). Constitutive constants and restoration mechanism are compared between these materials. While Fe3A1 is hardly a light metal, it is considerably lighter than most steels. Furthermore, like the other body centered cubic metals (BCC) (a-Fe, ß-Ti, ß-Zr and ß-brass), it exhibits a high degree of dynamic recovery (DRV) like Al alloys, producing easier hot workability than that of austentic stainless steels.

Jan 1, 2007

By R. B. Fermor

"AbstractAttention is drawn to the ventilation problems arising from the use of diesel vehicles underground, especially in view of the fact that diesel fumes in combination with other pollutants may be more harmful than diesel fumes alone or the other pollutants alone.Means for minimizing the harmful effects of using diesels underground are listed, and the quantities of air' required in mines in which diesel-powered vehicles are used are discussed. Mines are classified in three categories on the basis of severity of ventilation problems, and statistics are given for these categories.Details of the various components contributing to total ventilation needs are given, and the ventilation needs of individual mines in the three categories are listed. A description is given of the principles according to which main ventilation coursing is planned and the selection and siting of main fans is discussed.General Considerations in the Use of Diesel-Engined Vehicles UndergroundIN ORDER to reduce physiological hazards, present and latent, to workers in mines in which extensive use is made of diesel equipment underground, it is important that mine ventilation systems reduce the concentrations of rock dust, diesel fumes and particulate matter as rapidly as possible to an acceptable level in all parts of the mine.There is some evidence that the long-term effects of a combination of the above pollutants are greater than those of anyone of them alone, which makes the problem even more pressing."

Jan 1, 1977

By H. McLeod

Introduction In the period from 1939 to the present, Canada has experienced a remarkable industrial expansion, rising to probably seventh in rank amongst world countries. In the early part of this period, the desperate need for military supplies unloosed tremendous amounts of capital for building new factories and for expanding and converting existing facilities. Mines, factories, and other divisions of the industrial economy bent every energy toward greater and greater output. The result was an 80 per cent increase in the volume of the nation&apos;s production within a period of four years, a truly remarkable accomplishment and one in which the mining industry had a very vital part. After the critical year, 1944, the tempo of industry eased off a bit, dropping approximately 20 per cent by 1946. At this time the prospects or post-war industry were clouded by monetary and political chaos in overseas countries, by trade restrictions, and by market uncertainties. There was, of course, a pent-up demand, both at home and abroad, for civilian goods that had been curtailed during the war and for capital equipment that had been destroyed. In the midst of this world-wide uncertainty, if anyone had ventured to predict that by the end of 1950 Canada&apos;s industrial output would be back to the 1944 level and humming along at nearly twice the best pre-war pace, he would have been considered rash indeed. Yet this has been the case.

Jan 1, 1951

By George Brien, O&apos

The history of the lighting of mine workings dates back to the early part of the 18th century, when small candles known as tallow dips, were used. These were set or held in a lump of wet clay. When looking for gas the flame of. the candle was reduced to a mere glimmer by surrounding the wick below the flame with clay. The candle was then very cautiously raised from the floor toward the roof, the observer screening the brighter portion of the flame with his hand and watching for the first appearance of the pale blue cap above the flame, even at that time, known to indicate the presence of gas. When this appeared the candle was lowered quietly and its flame extinguished before attempting to drive out the gas. A very common and dangerous practice adopted at that time was to get rid of the gas by firing it. This was done by a person selected for his nerve rather than for his caution. Dressed in a? suit of dampened sackcloth or leather, this man well termed a "fireman", would lie prone on the floor of the roadway and light the gas above him by raising his candle fastened to the end of a long stick. If he survived, which was not always the case, he would withdraw promptly to fresh air after the flame had passed over him.

Jan 1, 1924

By C. H. B. Leitch

"The Bralorne-Pioneer deposit produced more gold than any other deposit in British Columbia over its 70 years of operation (130 kg or 4 million oz of Au, from 7 million tonnes of 18 glt ore). Mineralization is related to a suite of late Cretaceous albitite dykes of 85 to 90 Ma age. It thus occurred long after and is genetically unrelated to the Early Permian (275 Ma) Bralorne diorite and soda granite.The major veins strike about 110 degrees and dip north at 70 degrees, with slickensides plunging 45 degrees east that indicate last movement was reverse. Major ore shoots in the veins occupy somewhat less than 20% of the vein and plunge steeply west, roughly perpendicular to the slickensides. The structures that contain the veins probably formed at around 95 to 90 Ma during a strike-slip episode with easterly directed maximum compression.Disseminated pyrite, pyrrhotite, and minor chalcopyrite occur within envelopes up to several metres from the veins. Arsenopyrite is confined to vein selvages. Local sphalerite and galena appear to correlate with gold-rich portions of the veins. Traces of tetrahedrite and stibnite have been observed but tellurides have not. Gold is found principally as thin smeared flakes of the native metal in the black sulphidic septae of the strongly ribboned veins. Hydrothermal alteration envelopes around the veins grade outwards from intensely foliated quartz - ankerite - sercite (±fuchsite) to less sheared calcite - chlorite - albite to unsheared epidote -calcite.Open-space vein filling textures found in the deep (mesothermal) environment at Bralorne can be explained by a fault- valve model. High-angle reverse faults may have acted as fluid-pressure activated valves on geopressured reservoirs, causing large cyclic fluctuations in fluid pressure that promoted mineral deposition in an episodic fashion . The faults that were mineralized were reactivated sub-vertical former strike slip faults, oriented at a high angle to the northeast-directed stress in a compressive regime."

Jan 1, 1990