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By Ralph V. Stewart

"The asbestos orebody is contained within ultrabasic rocks of Precambrian age, being located in the continuous permafrost zone of the Quebec Ungava Peninsula, some 300 miles north of the tree line at approximate latitude 61'49' and longitude 73°58'.The asbestos deposit is at the western tip of a folded ultrabasic sill complex which trends northeast and covers an elliptical area 4.5 miles wide by 15 miles long. Locally. the asbestos occurs in. a completely serpentinized dunite rock. The principal rock types in the vicinity of the ore-body originally consisted of dunite, peridotite and pyroxenite, all of which have experienced at least two periods of alteration, so that no fresh rock now remains.The main ore zone in the open pit is approximately one quarter mile in length, 150 to 200 feet in width, and plunges at 25 to 30 degrees in a northeast direction below surface, to a vertical depth of at least 1,200 feet, Consider¬able tectonic activity resulted in favourable structural conditions which culminated in the formation of the ore zone in its present form.The deposit consists principally of cross-fibre ""gash type"" veins which vary in length from several inches to several feet. The principal fibre vein direction is parallel to the dip of the enclosing serpentinized dunite and sill complex.Some of the problems encountered during diamond drill¬ing in permafrost are briefly discussed."

Jan 1, 1976

By Harry J. Cain

Introduction The property of Pioneer Gold Mines of B. C., Limited, is located in the Lillooet mining district of British Columbia, on Cadwallader creek, 54 miles distant by motor road from Shalalth, a station on the Pacific Great Eastern railway. Milling by the present Company was commenced in 1924, a small amalgamation plant, consisting of a crusher, Bryan mill, and plates being operated until 1928. Tailing from this plant was impounded and later treated in the 100-ton continuous counter-current decantation cyanide plant which was erected during 1927-28 and placed in operation during May of 1928. A second cyanide plant, employing continuous counter-current decantation, having a nominal capacity of 200 tons, has been erected during the past few months and was put into operation during September of the present year. The ultimate capacity of the combined units of the present mill has not been determined, but it is expected to be much in excess of the rated capacity. The Ore The ore, as received at the mill, consists chiefly of quartz carrying free gold, with small amounts of pyrite, arsenopyrite, and pyrrhotite in evidence, though probably amounting to less than one per cent of the total. Some gold is very closely associated with the sulphides. The country rock is a basic igneous rock, probably an augite diorite. Near the vein it is highly altered to sericite, which slimes readily on grinding, and does not settle very well. The quartz is of two types, clear and ribbon. In the latter, the ribbons, which are not much thicker than paper, consist of shattered sulphides. In crushing this ribbon quartz, breakage is often along the streaks, exposing these shattered faces to advantage in subsequent treatment. While gold is the metal for which the ore is mined, some silver is also present and is paid for by the mint. It is, however, unimportant from a commercial viewpoint. From the standpoint of crushing and grinding, the ore might be termed 'medium 'hard'.

Jan 1, 1932

By S. M. Bradshaw, E. Charikinya

"Microwave induced cracks have the potential to enhance metal recovery from coarse sphalerite particles in heap leaching operations by creating new crack surface areas for lixiviant and enhancing value mineral exposure. The mode of fracture and the extent of mineral exposure due to microwave induced cracks have not yet been investigated. The objective of this study was to determine the extent of particle damage and mineral exposure in microwave treated particles. This was done using X-ray computed tomography (XCT) and image analysis techniques. XCT analysis was conducted on small (–5+4.75 mm), medium (–16+9.5 mm), and large (–25+19 mm) sphalerite ore particles before and after microwave treatment (MT). Geometrical properties, such as volume and surface area of each mineral phase in each particle was determined from the XCT reconstructed images using VGStudioMax image analysis software. These geometrical properties were used to calculate the interfacial areas of sulphide mineral grains in microwave treated particles before and after MT. The ratio of specific interfacial area after MT to specific interfacial area before treatment was used as an indicator of the degree of preferential grain boundary fracture. The results showed significant grain boundary fracture after MT at all sizes. For small sized particles, about 31% of the interfacial area was lost compared to 23 and 16% for medium and large particles, respectively. The results also showed an increase in the degree of mineral grain exposure of 28, 26, and 15% for small, medium, and large particles, respectively, after MT. These results provide experimental evidence supporting improved mineral exposure due to MT. INTRODUCTIONFor some years it has been suggested that microwave treatment (MT) of ores might result in preferential grain boundary fracture that would have benefits such as improved grain exposure and particle weakening. (Kingman, 2006). Most of the experimental work investigating the application of microwaves to mineral processing flow sheets has focused on assessing the benefits of applying microwave technology to flow sheets consisting of size reduction and mechanical flotation cells (Kingman et al., 2004). Experimental studies have shown that coarse crushing during tertiary grinding of microwave treated ore resulted in a better liberated coarser flotation feed (Scott, Bradshaw, & Eksteen, 2008). It has been suggested that improved liberation in milled flotation feed, was due to the presence of grain boundary fracture in microwave treated particles. However, this improvement in coarse particle liberation does not necessarily translate to a significant improvement in downstream flotation recovery (Kobusheshe, 2010). This is as a result of the size limit to the flotation of coarse material, due to detachment forces acting on particle-bubble aggregates, which increase as the particle size increases (Jameson, 2012). Current conventional, mechanically agitated flotation cells are not designed to float coarse material (Jameson, 2012). Hence it has been difficult to show the downstream processing benefits of applying microwaves to ores processed by comminution followed by flotation (Kobusheshe, 2010). It is clear from investigations carried out so far that inappropriate downstream exploitation of microwave treated ore would fail to realise a meaningful process benefit (Kobusheshe, 2010; Ali & Bradshaw, 2011)."

Jan 1, 2016

By T. G. Joseph, M. J. Bolster

ABSTRACT This paper explores passive seismic measurement as an alternative, nonintrusive approach to conducting annual brake testing on surface mine sites. Dictated by the test site location, this evaluation adhered to the brake testing procedure as per British Columbia occupational health and safety regulations. Results showed excellent correlation to those reported via conventional practice: Comparing stopping distance, time, and velocity for the proposed instantaneous passive seismic versus conventional approaches, less than a 0.5% variance was evident. A viable alternative, the passive seismic approach, allowed an entire fleet of trucks to be sequentially evaluated for annual brake testing without disrupting operations by installing mechanical testing equipment.

Jan 1, 2012

By H. T. Fargey

This paper considers the social, economic and political factors and their influence on future production and marketing of Western Canadian minerals. Among the subjects discussed are inflation, taxation, anti-combines legislation, unstable international currency relationships, economic nationalism and protectionism, the European Common Market and environmentalism.

Jan 1, 1973

By Minghao Hu, Hongbo Zhao, Jun Wang, Wenqing Qin, Rui Liao, Central South University

"In the present work, X-ray diffraction (XRD) analysis, X-ray photoelectron spectroscopy (XPS) analysis and electrochemical analysis were carried out to investigate the intermediate species and electrochemical dissolution process of chalcopyrite in the presence of sulfur and iron oxidizing microorganisms. For bioleaching of chalcopyrite by the sulfur oxidizing microorganism Acidithiobacillus caldus, the redox potential was always lower than the appropriate value and chalcopyrite was mainly directly oxidized to polysulfide (Sn 2-), thus resulting in low copper extraction. As for bioleaching of chalcopyrite by the iron oxidizing microorganism Leptospirillum ferriphilum, chalcopyrite was mainly directly oxidized to polysulfide at the initial stage where redox potential was lower than the appropriate value and resulted in low dissolution rate. At the middle stage where redox potential was appropriate (about 350–480 mV vs. Ag/AgCl), chalcopyrite was mainly transformed to intermediate species of Cu2S rather than polysulfide, thus resulting in high dissolution rate. At the later stage where redox potential was higher than the appropriate value, chalcopyrite was mainly directly oxidized to polysulfide which caused the later passivation of chalcopyrite. Finally, a model of electrochemical dissolution process of chalcopyrite in the presence of sulfur and iron oxidizing microorganisms was provided.INTRODUCTIONBiohydrometallurgy is considered as one promising mineral processing technique in processing low grade ores due to the advantages of simplicity, low cost and eco-friendly. Chalcopyrite (CuFeS2) is the most abundant copper-bearing resource, accounting for appropriately 70% of the known reserves in the world, while is recalcitrant to bio-hydrometallurgy mainly due to the coated passivation layer (Klauber, 2008; Li, Kawashima, Li, Chandra, & Gerson, 2013). However, the detailed dissolution and passivation mechanisms of chalcopyrite bioleaching are still uncertain. The microorganisms assisting chalcopyrite dissolution can be mainly classified into three types, including mesophilic microorganisms (e.g., Acidithiobacillus ferrooxidans, Acidithiobacillus thiooxidans and Leptospirillum ferrooxidans), moderately thermophilic microorganisms (e.g., Acidithiobacillus caldus, Sulfobacillus thermosulfidooxidans and Leptospirillum ferriphilum), and extremely thermophilic microorganisms (e.g., Metallosphaera sedula, Sulfolobus sp., Acidianus sp., and Sulfurcoccus mirabilis). Moderately thermophilic microorganisms have a better prospect in the future industrial application of chalcopyrite bio-hydrometallurgy (Olson, Brierley, & Brierley, 2003; Rohwerder, Gehrke, Kinzler, & Sand, 2003). Hence, investigating the detailed dissolution and passivation mechanisms of chalcopyrite bioleaching by moderately thermophilic microorganisms is of important significance, which will provide essential information for promoting chalcopyrite bioleaching by moderately thermophilic microorganisms in laboratory or industrial plant."

Jan 1, 2016

By R. Boom

Corus Umuiden, formerly Hoogovens, was the first steel plant in Europe after Voest to introduce oxygen steelmaking. In the decision-making process contacts with Dofasco in Canada about the production of formability steel grades were crucial. In developing oxygen (LD-) steelmaking high liquid steel output rates had to be combined with accurate process control. For ingot casting static models with input control and sampling during interrupted blowing were sufficient to deliver liquid steel within the required carbon, phosphorus, sulphur and temperature windows. Computers were introduced to perform the complicated charge calculations. Continuous casting called for strict control of composition and temperature at process end point and made predictable timing crucial. Dynamic control was introduced based upon sub lance measurements and waste gas analysis. Reliable disposable measurement sensors were developed in a concerted international action. Dissolved oxygen at blow end deteriorated the quality of low carbon aluminium killed steel grades. Blowing gases through the converter bottom improved process kinetics, resulting in lower carbon-oxygen products, yield increase and better phosphorus removal and generated new families of hybrid blowing processes. Introduction of secondary metallurgy facilities such as argon stirring stations, vacuum degassers and ladle furnaces relieved the demands for strict BOF end point control. Desulphurisation of hot metal became standard practice. In regions with scrap shortage hot metal desiliconisation followed by dephosphorisation, was introduced in the blast furnace cast house and hot metal transfer ladles. Later redundant converter vessels were used for pre-treatment, resulting in a two-stage process. The fundamentals of oxygen steelmaking are described and a vision on the future is presented.

Jan 1, 2004

By F. Sorenson, P. A. Castellarini, F. Garbarino, M. N. Garcia

"Recently, significant efforts to improve productivity from the tight intervals of the Mulichinco Formation within the Sierra Chata Field in the Neuquén Basin have been ongoing. Because conventional high quality reservoirs were being developed in this field, a proper reservoir understanding and completion approach was applied. After developing these high permeability reservoirs, the operator began evaluating the tight intervals and new areas within the field, but a completely different approach was necessary to achieve motivating production improvement.An extensive study to help enhance reservoir understanding and identify key factors controlling productivity of these tight intervals (which tend to be in the range of 5 µD) has been ongoing. Some of the issues discussed in this study are 1) petrophysical review, 2) rock properties calibration, 3) geomechanics understanding, 4) faulting and micro faulting/lineaments description, 5) stimulation and completions review and, 6) understanding key production drivers.As in many other tight reservoir projects, a considerable area of the reservoir must be effectively stimulated during the hydraulic fracturing process to achieve economic productivity. Two critical issues hinder these objectives. First, the low permeability in addition to a pore pressure close to or even lower than hydrostatic are critical characteristics when attempting to flow back the well and clean up fractures. Second, very high horizontal stress anisotropy resulting from a strike slip stress regime promotes the generation of simple planar bi-wing fractures. It is well-known that this fracture geometry will contact much less reservoir area compared to more complex fractures, as the operator would normally intend to create at very low permeability reservoirs.This paper discusses these issues and how they were addressed. A pilot drilling and completion program was initiated during 2012 to validate this study. Key factors include well location relative to formation unconformities, their orientation relative to the far field principal stresses, hydraulic fractures generated, and overall completion design."

Jan 1, 2015

During heap leaching of secondary copper sulphide ores operated at low heap temperatures and high levels of leach solution salinity, copper recovery is usually unsatisfactory, due to a slow chemical and bacteriological leaching of the covellite minerals either formed from leaching of chalcocite or naturally occurring in ores. A laboratory test program was conducted to investigate the effect of leach solution temperature in the range of 20 to 50°C on copper extraction during stirred reactor, bottle roll, and short column leaching of fresh or heap leached secondary copper sulphide ores. It was demonstrated that increasing heap temperature is an effective approach for improving recovery of copper from secondary copper sulphide ores. A review of the technologies available for heating heap leach solution or decreasing solution salinity to improve copper recovery from secondary sulphide ore indicates that an integration of copper concentrate pressure leaching with heap leaching is potentially a cost-effective approach. A copper flotation concentrate sample was tested through pressure oxidation with the use of heap leach solutions of varying strengths for the repulping of the concentrate in order to examine its effect on pressure oxidation performance. The test results indicate that use of heap leach solution of high salinity in the pressure oxidation process does not cause a negative impact on the process performance for copper extraction, sulphide oxidation, and recovery of gold (if present) from pressure leach residue, and has additional advantages of removing the bacterially inhibitory aluminum from heap leach solution and generating more acid and ferric iron in the pregnant leach solution. A flowsheet configuration for full integration of the copper concentrate pressure oxidation with heap leaching of secondary copper sulphide ore is proposed and discussed.

Jan 1, 2014

By L. C. Lien

Tower crane layout (TCL) is a typical construction site layout (CSL) problem, which is suitable for a wide range of work assignments and site conditions. Tower crane is one of the key facilities for vertical and horizontal transportation of materials, especially for heavy prefabrication units such as steel beams, ready mixed concrete, prefabricated elements and large panel formwork such as machinery and equipment, and a wide variety of other building materials within a construction site. However, it is a difficult combinatorial optimization problem to determine the locations of tower cranes with materials quantity supply and demand for engineers. Swarm intelligence (SI) was very popular and widely used in many complex optimization problems which was collective behaviour of social systems such as honey bees (bee algorithm, BA) and birds (particle swarm optimization, PSO). This study applied a hybrid swarm algorithm namely particle bee algorithm (PBA) based on a particular intelligent behaviour of honey bee and bird swarms by integrates theirs advantages. This study compares the performance of PBA with BA and PSO for a proposed hypothetical construction engineering of TCL with materials quantity supply and demand problem. Results show that PBA performs better performance than the mentioned algorithms on a proposed hypothetical TCL problem.

Aug 1, 2013

By J. Oré

An alternative method for dewatering slurry (tailings) is the use of geocontainers (MacTubes). The practical application of this work was carried out in the concentrator plant of the Raura Mining Company, located in the occidental mountain between Huánuco and Lima in Peru?s central highland. For the development of the research, the MATLAB R2012a software MGeST (v. 1.0) was used (Slurry Geocontainer Maccaferri Treatment). MGeST is used for sizing MacTubes, which allows determination of the most important design parameters, such as height (H), filling residual pressure (P1O ), strength of geosynthetic (T), and dehydration height. Compared with GeoCoPS v. 3.0, there is a maximum difference of 3% between the results obtained. The tailing to be treated in the MacTube have a specific weight of 11.62 kN/m3. After several tests it was determined that a MacTube of an apparent opening size of 0.22 mm was required for this specific weight.

Aug 1, 2013

?Podolsky Water treatment plant discharges to Norman North bog which drains into Whistle / Post Creek watershed and into Wanapitei Lake ?Whistle Mine closed and reclaimed but continues to treat and discharge water to Whistle Creek

May 1, 2009

By M. R. Swaan, G. J. Stewart

"ABSTRACTThe application of failsafe techniques to ask the ""What if"" questions about any process has been well established in the chemical industry for many years. The unusual number of fatalities that occurred in Ontario during 1986-87, prompted Inco management to look at the Fail Safe techniques as a method of improving safety performance.INTRODUCTIONOne of the major areas at any time for potentially disastrous accidents is the shaft, where all men and materials must travel. In April 1987, Inco's Thompson Mine's first Fail Safe Team was established to look at its shaft operations. The initial group of eight people was made up of hourly equipment operators, mine foremen, engineering, maintenance and the superintendent. This group took the name of Shaft Risk Analysis Team or SRAT.The many tasks or jobs that are performed in a shaft prompted the team to divide the work under six major headings; slinging, moving men, skipping, dewatering, shaft inspections and moving materials. Each of these areas contained many different tasks which are interrelated. The only way to understand this interrelationship was to flow chart the steps that actually occur in getting any job done.The flow charting is done by the foreman and operators using existing standard manuals and their experience of what actually takes place. In many cases, it soon became apparent that they had been ""working around"" many problems created by their standards. Fine tuning of these flow charts takes place at the weekly meetings, where input from all involved leads to a better understanding of the actual job being analyzed and its potential hazards. Two major points need to be emphasized in getting good flow charting at a mine:I. It must never be blame oriented or you will never discover how the jobs are actually done and hence you won't know what to improve.2 . All team members must have equal voting rights in deciding how to put the charts together so that they have ownership of the finished product. It is far too easy to end up with amanagement view of the way it should be. Many different techniques or methods are being employed to improve the tasks and reduce the risks associated with any job once the basic flow chart is established. The ones found to be the most useful are highlighted."

Jan 1, 1989

By H. W. Leon, F. J. Ellis

"This paper covers the new six-strand curved-mould billet casting machine at the Contrecoeur Works of SidbecDosco. It commenced production of 3 Yz-in. square billets at the beginning of January 1972. Together with two 100- ton ultra-high-power electric furnaces in a new meltshop, it is the principal source of billets for the existing rod and bar mill also located at Contrecoeur. The paper develops the reasoning for casting-to-size 3Y2 -in. billets and for choosing a six-strand machine. It indicates the significance of Sidbec-Dosco Montreal Works' extensive experience in operating a four-strand curvedmould billet machine since 1965 and the ways in which this experience influenced the design and operation of the new caster. Machine features are described in detail, as are the reasons for some of the features. The installation, checkout and crew training are briefly discussed as well as the tundish teeming trials. The first cast on January 5, 1972, is covered and a log is shown of the first casts to an empty ladle. There are operating statistics covering the first 100 casts, which produced 8000 tons of good billets in ten weeks of operation. Machine performance and billet quality were good and the few minor problems encountered are described."

Jan 1, 1973

By Sylvie Lévesque, Frederic Couët, Laura Pérez-Barnuevo, Cory Hennessey

Determining mineralogical characteristics of samples throughout the iron ore concentration process – from drill core samples up to the concentrate – is critical to process improvement and remediation. However, assessment of mineral proportions, liberation, and texture, although essential, can be time-consuming and costly. Thus, a mineralogical study is often not performed or only restricted to a limited number of samples. New iron ore deposits or new ore zones in active mines will bring new challenges as they are known to be problematic due to their lower grades, complex textures and presence of mineral impurities. In those cases, applied process mineralogy will be necessary to understand and to diagnose potential processing issues. To take full advantage of mineralogical information along the iron ore concentration process, new tools are being developed to provide mineralogical data based on texture, composition and liberation. In an early stage at the mine, the automated identification of drill core textures could provide essential information for the prediction of ore concentrability and grindability. In a later stage, the automated modal tool, combining the knowledge of the iron ore mineralogy of a specific deposit and the results of chemical analyses, can quantify the mineral proportions of the ore; results show good agreement between mineral estimation via chemical analysis and modal analysis using a Mineral Liberation Analyser. A bulk mineralogical analyser allowing semi-quantitative evaluation of the liberation of iron oxides is being validated. The results from the bulk mineralogical analyser will eventually be linked with the mineral proportions issued by the automated modal tool to provide complete mineralogical characteristics of iron ore samples. Ultimately, these mineralogical tools could provide valuable and timely insight for predicting concentrators’ performances or troubleshooting gravity separation processes.

Jan 1, 2016

By Glenville A. Collins

IN 1932, Horace Onyett at Oroville, California, built a practical floating washing plant along the general lines as now known, using a 24 in. by 12 ft. trammel; it was fed with a ½ yard dragline bucket, rated then at 200 yards per day. Onyett dubbed his plant a 'Doodlebug' which name has clung to this type of operation ever since. In general, the 'Doodlebug' dredge is the outgrowth of the depression of 1929, wherein many dirt contractors had surplus idle equipment and a few of them ventured to use it for placer mining. Many such plants were impractical and poorly designed and adapted often to locations not suited to the purpose. However out of the general idea came refinements until today dragline dredging has a very definite place in the gold production of the world. Many of the early operators, being mainly contractors without mining experience or technical knowledge of gold saving, geology, or mechanical design, naturally went through stages of trial and error until a workable unit became standard practice. Credit should be given Bodenson Iron Works of San Francisco, who did a notable job of pioneering and building of floating washing plants; also, to Lord and Bishop, contractors of Sacramento, who were among the early operators, and to several others who built and rebuilt their plants until the weak spots were strengthened to take the beating required, and yet deliver a high degree of efficiency.

Jan 1, 1945

By Francis Wm. Gray

The preparation of a paper read before this Society in 1927 on Undersea Mining led to representations to the Deputy Minister of Mines at Ottawa, Dr. Chas. Camsell, and to the Director of the Geological Survey and the Director of the Mines Branch, which resulted in the undertaking by these bodies of a geological, physical, and chemical survey of the Sydney coalfield, combined with revision of the geological maps, on all of which much progress has been made. Preliminary studies revealed the necessity for a new base-map on a scale that would permit the representation of the whole coalfield from cape Dauphin to Mira bay on one sheet, and in the making of this map the Geodetic and Topographical Surveys have collaborated, with the assistance of airplane surveys for filling-in of detail. The new map will show all the data accumulated by 50 years of active mining and will show also the extent of mine workings, with level-contours under the sea. Dr. W. A. Bell, of the Geological Survey, has, over a number of seasons, studied in the field the historical geology with the purpose of elucidating the sequence of earth movements that have determined the structure of the coalfields, especially those that have governed the course and extent of the complementary folds that traverse the Sydney coalfield. Dr. B. R. MacKay, of the Survey, and the officers of the Fuel Testing Laboratories at Ottawa have made exhaustive studies of the Phalen seam, chemical and microscopic, intended to elucidate the conditions under which this seam was deposited, and some very interesting conclusions have been reached.

Jan 1, 1934

By J. Ouellet

The design of hydrostatic liner for a deep potash mine shaft in Saskatchewan poses tremendous technological challenges. Technology has evolved to a point where one could consider a new innovative approach to hydrostatic liner design. But there is still a place for conventional technologies such as cast iron tubbings. As will be discussed in this paper, improvement to manufacturing process, installation procedures and even new materials can bring this technology to an excellent level of performance. With the spur of new projects in the potash industry of Saskatchewan, the authors worked in various shaft liner designs from the conceptual stage through to the construction phase. They were either directly leading the design work on some of these projects or acting as an external reviewer on others. Most of these shaft liner designs involved cast iron tubbing technology and ground freezing. The major challenge in sinking potash shafts in Saskatchewan is to go through a water-bearing ground formation under high pressure, known as the Blairmore or Manville fm. The only proven stabilizing technology for these formations is ground freezing. For a potash shaft, dry shaft conditions are highly desired, so a fully waterproof hydrostatic liner is required. All the existing potash mine shafts in Saskatchewan, except for two with composite steelconcrete lining, used the cast iron tubbing technology. Two new shaft tubbing liners have been constructed recently, one in the Athabasca Basin and one for a potash mine in Saskatchewan. When the authors began working on these new projects, what became quickly evident is that the technological knowhow for designing and constructing tubbing liners was no longer available within Canada and that the past construction methods used to sink tubbing lined shafts was obsolete. The tubbing liner for the shafts sunk in the sixties were designed either by German or British companies. In both of these countries only few tubbing lined shafts were sunk in last 40 years and the technology used in the sixties was not improved. There are only few countries where tubbing is routinely produced and installed: China, Russia, Ukraine and Poland. Out of these countries Poland is the one where this technology is the most advanced. The authors, working in close collaboration with engineers from Poland, attempted to rebuild this knowledge for the mining industry in Canada. This process involved thorough analysis of old technical reports, literature review and study of current polish design and construction practices as well as site visits of existing shafts. Through actual construction experience, some lessons were learned as well as ideas for improvements. In this paper, the authors will present a succinct review of design and procurement process. But, the practical aspects of the construction and installation methodology will be treated with more emphasis, more specifically the practice leading to good liner performance. Some of the poorly understood technical aspects of tubbing installation will be discussed more thoroughly and some currently accepted myths dispelled.

Aug 1, 2013

By Alan E. Cameron

WE assemble again today in this comfortable, hospitable Inn to begin this, the 58th, Meeting of our Society. It is just a year ago when last we met but that year was, probably, the most portentious year in the whole history of mankind. In that year, the German 'Atlantic Wall' was broached, the Rhine was crossed, and Germany, as a Nation, has ceased to be. The agony of Europe is over; convalescence may be, probably will be, slow. But blood no longer flows in Europe. Time will heal the sores, cover the scars, regenerate the industries, rebuild the cities, and re-establish the people. True, the war of all wars is not yet over. True, a bloody conflict remains . But, the power of the United Nations now converges on one target. The rain of blood will be heavy. We can hope the storm will be short. The sun is on the horizon. The light of peace 1s in the sky. What of that Peace? Are we ready for it? Have we a 'sure foundation ' for our future world? Are the footings under that foundation broad and substantial? Can we look forward with confidence to a lasting peace and a fruitful life? The United Nations, even as this is being written, are in conference in San Francisco, placing the footings, rearing the foundations for a world edifice. There are bickerings; there are jealousies. The world is tired, and a tired family always squabbles. We can, we must, believe that the decisions they make, the edifices they rear, will be better than anything we each could effect separately. It will be a compromise, probably; it will carry things that will hurt us, just as it will carry things that will hurt others. We can, we must, believe that the good of the whole is a greater good than the good of the part. Each Nation within the United Nations must sacrifice something, each part of each Nation must sacrifice something, each individual within each part of each nation must contribute something, if the whole is to be wholesome. Sacrifice and contribution must be the order of the day if the New World we are about to build is to be worth while. What of Nova Scotia? The world has travelled far in the last year; how far has Nova Scotia gone? Canada has preparations for the Peace under way; what has Nova Scotia done? Is Nova Scotia preparing counter measures for the sacrifices it must make? Is each of us ready to contribute his share?

Jan 1, 1945

By Colin E. Dunn

The high mobility of gold within the plant kingdom results in detectable accumulations of gold in many plants. Concentrations vary within individuals, among species, and with seasons. From an evaluation of the chemistry of easily acce sible organs of common pecies in the northern forests, it is concluded that alder twigs (or leaves) and conifer bark scales are the vegetation components of greatest use in the earch for concealed gold mineralization. Maximum anomaly enhancement is obtained from twigs collected in the spring. Examples are given of urvey conducted in the La Ronge Domain using 1) jack pine bark (A nglo-Rouyn and Upise Lake areas) ; 2) alder twig (McLennan Lake) ; 3) black spruce bark (Rod Zone near Mallard Lake, and at Waddy Lake) ; and 4) multi-media (Tower Lake). At the latter two sites gold-bearing till is blanketed with late glacial material. Gold enrichment in the plants suggest that the roots are ab orbing gold from the underlying till. Complex processe control the uptake and retention of gold in plants. An understanding of these processes pem1its biogeochemistry to assist in locating near- urface mineralization .

Jan 1, 1986