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By G. G. Campbell

"HistoricalBARYTES was mined in Nova Scotia as early as 1874 from a deposit at Five Islands, on the north shore of Minas Basin. The first record of the presence of the mineral at the Walton site appears in a report by Selwyn in l893, who states: ""Barytes in considerable quantity occurs in veins in lime-stones at Walton and Pembroke"". The exact site of the present workings was marked •on a map published by Fletcher in 1905.The economic •possibilities of this deposit, however, were not recognized until 1940, at which time we were at war with Germany, who up to that time had supplied 50 per cent of the world's requirements.At that time the Nova Scotia Department of Mines, recognizing the need for certain strategic minerals, induced Canadian Industrial Minerals, Limited, to send prospectors into 'the area to look for manganese. No manganese deposits were found, but a deposit of barytes was directed to their attention, and exploration and development work on the occurrence was proceeded with.IntroductionThe south shore of Minas Basin between the Avon river at Windsor and the Stewiacke river at Maitland has long been known as a potential source of mineral wealth. It had attracted the attention of mineralogists and in the past had produced considerable tonnages of manganese ore and gypsum. Depletion of ore in surface and near surface deposits resulted in a dwindling production, until today only deposits of gypsum are worked."

Jan 1, 1952

By M. T. Ho, D. E. Wiley

The iron and steel industry accounts for almost 5 % of the total world CO2 emissions. Optimisation of the steelmaking process has led to significant reductions in the energy intensity to the point where it is now close to the thermodynamic limit. Further reductions are not likely to be achieved with efficiency improvement alone and will require the development of novel or breakthrough technologies. This paper will show the costs of implementing CO2 capture at direct atmospheric emission points for a number of iron and steel production processes. These include a conventional process, top gas recycling processes, the Corex and Hismelt smelt reduction processes and the Midrex direct reduction process. Depending on the point source emission, costs of capture with existing chemical absorption technology at iron and steel plants can be similar to capturing CO2 at pulverised coal fired power plants.

Jan 1, 2015

By K. S. Coley, G. A. Irons, T. Kaneyasu

"It is very important to reveal the lime dissolution mechanism in steelmaking slag, to promote its dissolution without calcium fluoride, which is now almost forbidden for use in most industrialized countries. In this research, the purpose was focused on the development of an experimental method to measure the mutual diffusivity of Ca2+ under the condition of lime dissolution into slag. By forming diffusion couples using a ""vacuum slag aspirating technique"", the method was established. The following mutual diffusivities of Ca2+, in CaO-SiO2-FeO slag systems, imitating oxygen steelmaking slag, were determined using this method:4.1*10-10 m2/s at 1400°C for 27wt.%CaO-53wt.%SiO2-20wt.%FeO slag,4.3* 10-10 m2/s and at 1400°C for 20wt.%CaO-40wt.%SiO2-40wt.%FeO slag, and 1.3*10-10 m2/s at 1250°C for 20wt.%CaO-40wt.%SiO2-40wt.%FeO slag.It was also verified that, if the basicity and ferrite content of the bulk slag are low, then a calcium silicate film forms on the lime surface, and drastically deters the lime dissolution."

Jan 1, 2004

By J. D. Campbell

"Coal is one of Alberta's major fuel resources, but its distribution, especially in the flat plains region, has been somewhat obscured by surficial deposits. After a period of neglect, easily strippable plains coal is presently approaching a position of dominance in electrical power production, a position it is likely to retain for a number of decades in the face of strong competition from hydro and nuclear power. Accordingly, the Research Council of Alberta has undertaken an inventory survey of the province's supplies of this resource.In the southern part of the province and in the north-central forest-fringe area, some strippable coal is found in the Belly River Formation and its equivalents, but major strippable coal reserves in large areas of central Alberta occur within the Edmonton Formation. The survey is planned on a reconnaissance scale, drilling test holes at 2-mile intervals in selected large areas. It appears to show that, in well-settled regions, large reserves of strippable coal are only to be expected where they have long been known; major presently unknown bodies of coal must be sought in unsettled regions or at depths too great for strip mining. However, such bodies might still be economically competitive with hydro and nuclear power in the production of electric power for some time to come."

Jan 1, 1967

By Bryon Cerklefskie, Michael Schulte

"This case study explores the usage of polymer ducting as a replacement to curtains and FRP for face ventilation in two coal mines. There are two mines looked at, one is the highest elevation underground coal mine in North America, the other is the gassiest mine in North America. The paper details the trials of both mines switching from FRP and curtain respectively to polymer ducting. The results discuss the ability for the mines to not only achieve consistent airflows and keep them in compliance but the unexpected positives. Mine A was allowed to do longer cross cuts due to increased air volume at the face. This drastically cut their costs of mining down due solely to modification of the ventilation cycle. Mine B saw economic benefits due to longer cuts between place changes. Both mines have documented lower dust, methane, noise, and improved wear and tear on their equipment as a result.INTRODUCTIONThe emergence of longwall mining in underground coal operations has resulted in new ventilation challenges. Numerous production crews strive to complete their development sections with enough time to adequately prepare for the upcoming longwall panel. Continuous miners will cut out two or three entry development sections per their ventilation plan, that is approved and controlled by MSHA (Mine Safety and Health Administration), which will drive amount of footage that can be mined at a time prior to installing roof support. At this moment the continuous miner, hereafter referred to as the CM, will back out of the entry and moves to the second entry to complete a similar cut. Typically, a roof bolter crew will pull in to the finished cut section and install ground support. This is called a place change style of production coal mining. There is an alternate method that includes a miner/bolter combination as well but that was not featured at either test site in this case study. Ventilation has to be provided to sweep the working face of each entry to control dust and gasses. Each task will have an MSHA prescribed ventilation requirement dependent on the dust levels and methane emissions of the rock for that particular mine. The CM, roof bolting and unused headings will each require constant ventilation but at different volumes. Since each working face is changing throughout the mining cycle the ventilation requirement in a working heading is never static and is changing with the working task.Traditional Ventilation ControlsTraditionally face ventilation for coal mining operations has been completed thru the usage of a curtain system and\or using auxiliary fans and ventilation tubing. Room and pillar mining systems typically utilize curtain systems, which use curtain walls that are installed by the miners by erecting wood framing and covering it with brattice curtain. This splits the drift width to allow fresh air to sweep the face and take the contaminated air and dust behind the curtain to the ventilation exhaust\return area of the mine. This method is difficult to adjust the airflow from entry to entry during changing cycles and requires that a wider drift is mined out in order to have enough room for the brattice wall. In operations that require roof bolting, this method limits the length of the cuts from the CM prior to advancing and can lead to not providing enough ventilation to keep dust and methane levels below compliance requirements."

Jan 1, 2019

By Alexander Smith

"The Silver Standard mine is 6 miles by road northwest of New Hazelton, B.C., a small town on the northern line of the Canadian National Railways some l 75 miles northeast of Prince Rupert. The deposits lie on the western slope of Glen Mountain (elevation 2,100 feet), with the main adit, mill, and campsite at 1,300 feet. The deposits were found in 1910, shortly after the area had been swept by forest fire and during a period of prospecting activity spurred by the construction of the railway. Crude ore only was shipped until 1918, when a 50-ton gravity mill was built which operated until 1922. Gross value of production of this period, at present metal prices, was about $1,000,000.In 1947 the present company was formed and a 50-ton flotation mill installed. Production from 1948 to 1955 has been in excess of $10,000,000, and net smelter returns about two-thirds of this amount. More than 60 per cent of the production and 80 per cent of the profit have come from one vein, No. 6. On the 1,300-foot level this vein had an ore section 375 feet long and 2.5 feet wide, averaging 0.18 ounces gold, 85 ounces silver, 10 per cent lead, and 16 per cent zinc.The mine workings follow a simple pattern. A series of parallel veins, striking northeast and dipping southeast, are numbered from 0 to 12, starting at the northwest. They lie within a zone trending south 70 degrees east, and the distance between Nos. 0 and 12 veins is about one mile. Recently several cross-veins, dipping northeast, have been found between Nos. 8 and 12. They are apparently of the same type as the others, though they may not have the same structural controls. They could be an important new source of ore.The mine has been developed principally by crosscut adits at the 1,500- and 1,300-foot levels and a 510-foot shaft with levels at I, 150, 1,000, ·and 850 feet. Drifts and crosscuts total 17,000 feet, chiefly on Nos. I, 4, 6, 7, and 8 veins. The drifts are stoped by shrinkage, top shrinkage rill, cut-and-fill with resuing, or open stope methods. The mill produces a lead-silver-gold-copper concentrate and a zinc concentrate, with indicated recovery of more than 96 per cent (4)."

Jan 1, 1949

By Gerald A. Crawford

"1880s - Unmasking the Sudbury Basin Falconbridge Ltd. turned 60 in 1988 but its roots go back more than a century to the discovery and development of the mineral resources of the Sudbury Basin. Nickel was first identified in the area in 1856 but sustained exploration awaited the early 1880s and the advance of the CPR westward from Sudbury. Rock was laid bare in the right-of-way and by forest fires and logging. Reddish oxidized outcropping or ""gossan"" were exposed, heralding the presence of nickel as the shape of this astounding geological formation gradually began to emerge. Many great mines of the area were opened up in this period on the south rim of the Basin west of Sudbury. To the east the ore dips below overburden, however, and Falconbridge remained a mere dot on the map until the turn of the century when Thomas Edison detected a magnetic occurrence by dip needle."

Jan 1, 1999

By R. A. McGuire

THE recorded production of the Sheep Creek camp from 1900, when the Yellowstone Mining Company first put its mill into operation, to the present day is in excess of $17,500,000. Of this total, $2,500,000 can be attributed to the early period from 1900 to 1916, at which time increased costs of labour and material due to the Great War forced abandonment of any operations on a large scale for a number of years. Since the camp was revived in 1929, at which time the Reno mine started large-scale operations, and the early 'thirties', when the increased price of gold induced the commencement of operations on other properties in the district, total gross production has been in excess of $15,000,000. In addition to the above totals, intermittent shipments were made by lessees and small operators, principally during the period of inactivity from 1916 to 1929, but no records of this production are available. The Sheep Creek camp would rank fifth in the Province-behind Rossland, Portland Canal, Bridge River, and Hedley-in gross gold production, but, because of relatively inexpensive mining and milling costs, would occupy a more prominent position in regard to total dividends paid. Operating mines at the present time include Reno Gold Mines, Gold Belt Mining Company, Kootenay Belle Gold Mines, and Sheep Creek Gold Mines. Each one of these companies, with the exception of Kootenay Belle, represents a consolidation of several smaller properties, all of which were in existence for a number of years prior to 1929. These four companies, at the present time, own, or hold options on, practically all the important claims in the district with the exception of a very few claims and fractions still held by private owners.

Jan 1, 1942

By Mohammad Reza Khalesi, Ruhollah Rezazadeh, Mohsen Izadi Yazdan Abadi, Mahmoud Abdollahy

"The rotary vacuum drum filter (RVDF) is widely used for dewatering in mining industrial. In general, different parameters have influence in the solid-liquid separation such as: solid percent, level of vacuum, particle size distribution, filter cloth and chemical additives. These parameters can influence on some variables such as cake moisture, throughput and filter cloth life time. The aim of this study is to propose some chemical additives to improve the rate of filtration and decrease cake moisture of Gol-E Gohar iron ore concentrate by using laboratory scale bottom feed vacuum filter and suggest a filter cloth with long life time (more than 400 hours). Effect of particle size distribution on filtration investigated in large scale by measuring the thickness of cake and cake moisture.Increasing molecular weight of anionic flocculant lead to increases throughput but cake moisture increases too; While the filter aid increases throughput and decreases cake moisture simultaneously; the combination of them show different behavior. TSS and filter cloth life time have directly relation with material and type of filter cloth weave. Depending to type of feed, two polyester and polypropylene filter cloth are suggested. More over twill and satin weave have the best results. To prove the laboratory results some industrial tests performed in Gol-E Gohar hematite iron ore concentrate plant.INTRODUCTION“The process of grinding and classification involves the use of large quantities of water. The separation of solids from liquids is usually achieved by gravity sedimentation in thickeners. For fine particles this is a slow process. In general, 75–80% of the water can be separated and removed by thickeners. For further water removal, filters are used where in excess of 90% of the water can be removed” (Gupta, 2006).“Many types of filters are available, which are broadly classified here as vacuum, pressure, precoat and depth filters. Each classification contains a number of sub-processes. A category of filter that uses vacuum induced driving forces and semipermeable media to facilitate the separation of solids from suspension. While pressure differences across the filter are limited to less than 85 KPa (usually 75 KPa), most units are capable of processing a wide range of feed materials in a continuous manner” (Rushton, 2008)."

Jan 1, 2016

By D. J. Scarpato

"Slope construction in shale can present some interesting challenges for geotechnical design engineers and contractors alike. There are challenges that can be expected and designed-for; however, all too frequently, such challenges manifest themselves as “surprises” in the field. Common constructability challenges can include those such as drill hole deviation during drilling for controlled blasting; and, excavation slope instability arising from inconsistent perimeter control drilling. Drill hole deviation results from the cumulative effects from both drilling mechanics and rock mass conditions. Once a hole has initiated the deviation trajectory, it is difficult to rectify drill steel position. Although such challenges are not necessarily unique to shale, they are often exacerbated by weak, weathered and transversely isotropic nature of bedrock conditions. All too often, the working assumption is that shale is “soft” and easily excavatable; however, this blanket assumption can prove to be costly. This paper is intended to provide design professionals and contractors with the practical considerations needed to avoid the “surprises” associated with drill hole deviation, and minimize the potential for costly claims.INTRODUCTIONFor all the slopes that have been excavated worldwide, and for such advancements in excavation technology and field characterization, one might be tempted to believe that the industry almost has slope development down to a science. This is frequently not the case, especially for weak/weathered and anisotropic bedrock. Excavation contractors are still pushed to the limits of what their technology can achieve, and engineers are all too often called to the field during construction, to make potentially risky onthe- fly decisions relative to excavatability, short and long-term slope stability, and project safety. Although there have been a host of other research papers and journal articles that have been written on the subject of deviation over the past 30 years (Brown, Geen, Sinha, 1981), the problems associated with drill hole deviation are still all too frequent. This fact is especially true for civil engineering surface excavations in bedrock."

Jan 1, 2015

By G. Deschênes

"In 2013, as the prices of precious metals dropped, investors moved their positions to equity markets for higher returns. As a result, the price of gold dropped further to below US$1200 per ounce, prompting additional substantial outflows from gold investments. In response to lagging gold prices, major gold producers initiated large asset write-downs and cost-cutting programmes. In 2015, this trend continues and gold mining stocks are close to lows not seen since the global financial crisis (GFC) of 2008. In the current economic climate many projects have marginal economics, and the number of projects that have competitive development and production costs is declining. A competitive edge is particularly important with the decreasing grades of orebodies, increasing complexity of the mineralogy, and increasingly demanding environmental constraints. In addition, higher cost producers seek to optimize their process t o reduce operating costs.This paper presents some highlights of three case studies on optimization of gold leaching strategies that improved the economics of brownfield projects. Processing of sulphide-bearing ores was optimized by using the synergy between cyanide, lead nitrate, and oxygen. The outcomes were significant reduction of retention times while maintaining or increasing gold extraction and reducing cyanide addition and effluent treatment costs. A stirred tank reactor experimental programme led to direct implementation of reliable leaching strategies from laboratory scale to production. This approach resulted in savings of $2.2 million to $15.2 million on the three brownfield projects discussed in this paper."

Jan 1, 2016

By W. Basuki, B. Setyotomo, L. Hakim, R. Hendrajaya

Due to high crack sensitivity of slab product of gas and oil line pipe application, its steel making process and alloy composition were evaluated and then improved to overcome its critical solidification process and reduced surface defects. The study was conducted at Slab Steel Plant Krakatau Steel. The purpose was to improve slab surface quality by reducing surface defects so that the slab surface doesn't need to be totally repaired. The method applied was by performing plant trial process, which the secondary process parameters such as alloying method and the casting parameters such as casting powder selection, metallurgical cooling, mould level control, and superheat were continuously monitored and then adjusted to the surface quality of the product. Based on the calculation of Ferrite potential of the steel, the chemical composition was designed to achieve optimum casting parameters in order to avoid high shrinkage during solidification. The results of the study are decreased surface defect quantity, and smooth casting process. The quantity of crack decreased by almost 90%. The slab surface repairing was significantly reduced from 85. % to less than 10%. These new casting parameters and developed alloy composition are then used and standardized for the mass production of the steel.

Jan 1, 2005

By J. E. Gill

"The Wasa Lake property is a block of about 1,640 acres in Beauchastel township, Quebec. Gold was discovered there first in 1936 in what is now known as the 'Southern area ( Fig. 1). Stripping and trenching were followed by 9,218 feet of diamond drilling in twenty holes. A number of good intersections were obtained, but their interpretation in terms of ore was difficult. A shaft was then sunk to 220 feet vertical depth. Thirteen hundred feet of lateral work and 543 feet of diamond drilling were completed at the 200-foot level before work was discontinued in 1938. Results up to this point had been just fair.Early in 1944, surface diamond drilling was resumed. The first hole cut material of ore grade in a strong shear zone 1,000 feet north of the old workings, and holes to the east and west showed this to be an extensive gold-bearing zone.In August 1945, a main working shaft was started. This has been sunk to 550 feet slope depth. A cross-cut at 390 feet vertical depth was driven to the ore zone and, by drifting and drilling at regular intervals, a length of 725 feet had been tested to December 31st, 1946 ( Figs. 1 and 2). The results check those from surface drilling quite closely.In the main zone, scoping widths from 8 to 40 feet and averaging about 25 feet are indicated. The grade after dilution should be about 0.15 oz. gold a ton and operation will probably start at 1,000 tons a day."

Jan 1, 1954

By C. Sui, J. E. Nesset, M. Li, J. Y. Kim, S. L. Chryssoulis

"A plant study of zinc rougher flotation at Brunswick Mining was conducted using lime, soda ash and a combination of both as the pH modifiers in order to establish the effects on sphalerite and pyrite kinetics and mineral selectivity. The plant sampling and analysis was augmented by surface analysis using TOF-LIMS, SEM and XPS as well as fundamental precipitation and surface-charge studies in the sphalerite Ca/C03/S04 system.The results revealed the important role of carbonate ions in cleaning the sphalerite surface for effective activation by CuS04 to occur, and the beneficial role of combined soda ash and lime in increasing pyrite and galena depression.1.0 IntroductionThe studies reported in this paper were initiated as part of an investigation into the causes of a particularly pronounced seasonal deterioration in metallurgical performance at the Brunswick Mining concentrator during the summer of 1995. The concentrator treats a complex base metal ore having a typical feed composition of 9.0% Zn, 3.5% Pb, 0.4% Cu and 100g/t Ag at a current throughput of 9,000 TPD, although at the time of the problem in 1995, the average production rate was closer to 10,500 TPD. Zinc, lead, copper and bulk (zinc-lead) concentrates are produced with overall metal recoveries of 86% zinc, 63% lead, 60% copper and 60% silver; results which are typical of the lower recoveries associated with fine-grained, highly complex VMS and SEDEX type deposits. The main economic minerals of interest are an iron-containing (7% Fe) sphalerite, galena and chalcopyrite with the main diluent (about 60% wt) being pyrite.Figure 1 shows a simplified flowsheet of the Brunswick milling circuit while the seasonal decrease in summer metallurgy in 1995 is illustrated in Figure 2. Of significance is the rapid drop in copper and lead recovery in June while there is an apparent delay until late August-September before the zinc deterioration reaches its lowest point. A more typical seasonal effect within the experience of the authors is the reverse of the Brunswick situation, namely an improvement in summer performance thought to be associated with improved differential flotation kinetics during warmer weather leading to better mineral selectivity. The historical Brunswick experience was particularly severe during the summer of 1995 with estimated incremental losses of $10 Million for this period. The potential of the very significant economic benefits to be gained from understanding and hopefully improving the annual drop in performance led to an investigation involving the minesite metallurgical group, the Noranda Technology Centre (NTC) as well as researchers in Professor Jim Finch's group at McGill and the surface analytical services and interpretive skills of AMTEL."

Jan 1, 1998

By N. Saracoglu, J. P. Golightly, R. H. Wallis, J. J. Brummer

"The McClean uranium deposits are located 11 km west northwest of the Rabbit Lake Mine. Their average grade is 1.8 % U3O8 , and they contain 6. 350 tonnes of uranium oxide in seven pods of variable grade and mineral assemblage. They are hosted by both basal Athabasca Group and the regolith developed on the underlying crystalline basement. The major mineral facies are: sulphide, arsenide, 'bleached', and hematite, with the important uranium minerals being coffinite, uraninite and pitchblende. Abundances of carbon and sulphur isotopes are consistent with their derivation from pyritic graphite in basement gneisses. Isotopes of oxygen and hydrogen suggest equilibration at temperatures of about 200°C. Ar39/ Ar40 age determination of illite associated with ore suggest mineralization began about 1300 m.y. ago and that significant alteration had ceased by about 1170 m.y. ago though Pb/ U data suggest the deposits continued to evolve into the Mesozoic.IntroductionThe McClean deposits lie on the eastern side of the Athabasca Basin of northern Saskatchewan where they are part of a cluster of uranium deposits lying west of Wollaston Lake (Fig. 1). The general stratigraphy is schematically portrayed in Figure 2 which emphasizes that mineralization is hosted by both the Athabasca Group and the underlying regolith and also that the deposits are preserved at depth and have not suffered from preand post-Pleistocene weathering and erosion. This circumstance, combined with their simple shape and the presence of seven separate zones of mineralization (pods) allows a description, based on over 450 fully cored drill holes, to be made of the wide variation in chemistry, grade, alteration patterns and position relative to the sub-Athabasca Group unconformity. Ar39 / Ar40 age determinations have been made of illites associated with regolith, Athabasca Group and mineralization and studies are in progress on C, S, 0 and H isotopes of mineralized material and host rocks. Only some of these data have been published; Brummer et al., (1981); Golightly et al., (1982); Bray et al., (1982); and Saracoglu et al., (1983). The only other published data on McClean geology are by Tremblay (1982, 1983)."

Jan 1, 1986

By Pravin Mathur

"Praxair's CoJet® technology was introduced in 1997 to effectively inject chemical energy in electric arc furnaces. Coherent jets were invented as a revolutionary means of injecting oxygen and other gases into the EAF and into converters. Today, steel makers have widely accepted this concept in over 70 EAFs worldwide. Indeed, the whole industry has shifted to this new standard for chemical energy input in EAFs. CoJet® technology has also been implemented successfully in BOF converters.This paper will review the principles of coherent jets as applied to steelmaking. The key learnings garnered from several furnaces are also reviewed. In addition, while the CoJet® program has been widely accepted worldwide, based on steady feedback received from customers and the market place, several programs are underway in development and commercialization. These enhancements and new applications of CoJet® technology are also overviewed in the paper."

Jan 1, 2004

By J. Clark

Erosion control during the mining cycle can be more effectively planned using Erosion and Sedimentation Control Plans (ESCPs). This raises the issue of who should develop an Erosion and Sedimentation Control Plan Guidance document (ESCPG) to standardize the content of ESCPs. A search for ESCPG documents in Canada revealed no examples for mine sites. In the U.S. there are a number of regulatory authorities who developed such documents for mine sites, including EPA. An ESCPG is expected to result in: (a) plans will be more standardized (b) more clarity and efficiency for those generating ESCPs; (c) assisting regulators tasked with reviewing/approving ESCPs; (d) providing guidance for the mine effluent permitting process relative to sediment control; (e) providing a basis for developing and including ESCPs in the Environmental Assessment (EA) phase and the mine economic assessment; (f) applying and optimizing ESCPs above the ?watersheds? of sediment ponds; (g) utilizing the ESCPG document for ?exploration? sites; (h) lowering the risk of adversely impacting water quality downstream of mining activities; (i) providing a methodology for determining the need for sedimentation pond(s) during the construction and production phases; and (j) providing a clear environmental sustainability message relative to sediment control if the mining industry takes the lead in developing an ESCPG. ESCPs will proactively create increased administrative (regulatory) efficiency in the EA and sub-EA reviews relative to erosion control and sediment release from mine sites. This also assists the new initiative in BC, One Project, One Process (OPOP) and synchronous permitting (a variation of concurrent permitting): as an example, enhanced erosion control planning at the EA phase then allows the synchronous permitting initiative to proceed efficiently, particularly for the mine permit (Ministry of Energy, Mines and Natural Gas) and effluent permit (Ministry of Environment). Approximately twenty more management plans (e.g. ARD/ML, explosive management, emergency response, hazardous waste, sediment pond operation, environmental effects, environmental sampling, etc.) may also be entered into the EA process to create increased efficiency, and then feed into the synchronous permitting effort. The BC OPOP initiative also adds support to the Canadian Federal ?One Project, One Review Process? approach. The ESCP and a sediment pond management plan will also address the Canadian Metal Mining Effluent Regulations requirement for all discharges from mine sites to meet a grab sample of 30 mg/L Total Suspended Solids.

Aug 1, 2013

By James A. Robertson

"This paper is the result of a continuing investigation begun in 1953 by government geologists and mining companies. Previous work is reviewed and the development of several stratigraphic nomenclatures and correlation schemes is traced, culminating with the interim report of the Federal-Provincial Committee on Huronian Stratigraphy formed in 1966.The stratigraphy, structure and correlation of the Huronian rocks of the Blind River area and the region between Sault Ste. Marie and Sudbury are reviewed. The area is underlain by three Precambrian units: (1) the Archean greenstones and granites, (2) the Huronian sedimentary and volcanic rocks and (3) the post-Huronian intrusive rocks. The Huronian rocks, largely quartzite and conglomerate with greywackes, argillites and carbonates, were laid down in shallow water transgressing over the eroded Archean basement. Thickness and facies changes indicate a northwesterly source, northerly overlap and deposition controlled by basement topography. Polymictic conglomerates, occurring at least at three horizons, represent tillites and are associated with varvites with dropped clasts. These are best developed in the Gowganda formation, which varies from a continental glacial environment in the north to a marine glacial environment in the southeast.There were at least three phases of post-Huronian igneous activity, probably related to several periods or phases of late Precambrian deformation and metamorphism: (1) sills of Nipissing diabase and rather younger diabase dikes; (2) the Cutler Granite and Croker Island Complex; and (3) dikes of Keweenawan olivine diabase.Copper mineralization is associated with the Nipissing diabase. The uranium ores are found in pyritic quartz-pebble conglomerate near the Huronian Archean unconformity, particularly in ancient valleys; they are considered to be placer deposits modified by later events. Uranium production from the Blind River camp to the end of 1966 was 128,160,096 pounds U308 valued at $1,203,840,848 derived from 56,077,179 tons of ore grading 0.11 per cent U308.Within the Blind River and adjacent areas, future discoveries will probably be the result of costly systematic deep-drilling programs accompanied by detailed geologic studies of the type carried out by oil companies and probably computer-oriented."

Jan 1, 1969

By X. Wu

Tunnel Boring Machines (TBMs) are widely used for tunneling in urban areas because of their high advance rate, precise as-built profile and minimal impact to buildings and traffic on the ground. For a tunnel built by a TBM, there are strict requirements on alignment control and safety. To meet these requirements, it is important to monitor the position of the TBM. In the current practice, the TBM position data, including advance distance and line and level deviations, are reported manually to the managers on a daily basis. To interpret and analyze the position data, the managers also need to refer to various construction drawings. This practice is untimely, inefficient, and error prone for decision making. To improve the current practice, an automatic approach for real-time as-built tunnel product modeling and visualization is proposed, based on TBM position and orientation data autonomously sourced from the Virtual Laser Target Board (VLTB) TBM Guidance System developed at University of Alberta. Related information of the tunnel project, such as the as-designed alignment, soil layers, the ground, existing utility lines, is also visualized together with the model of the as-built tunnel. The modeling algorithm is presented step by step. Its application in a real-life drainage tunnel project is discussed and limitations are also identified.

Aug 1, 2013

By M. J. Nicol, T. Moyo

Ammoniacal solutions are an effective lixiviant for the oxidative dissolution of some mineral sulphides. A detailed study of the anodic dissolution of chalcopyrite in ammonium sulphate-ammonium hydroxide solutions has been carried out using cyclic voltammetry, chrono-amperometry and rest potential measurements. The role of the copper(II)/copper(I) redox couple in the oxidation process has been evaluated. Rest potentials have been found not to be affected by oxygen but to increase with an increase in initial copper(II) concentration. Pseudo-steady-state anodic current densities measured in the absence of copper(II) ions at the rest potentials obtained in the presence of copper(II) ions increase with increasing concentration of copper(II) ions, confirming the positive effect of copper(II) ions on the rate of dissolution of the mineral. Cyclic voltametric and chrono-amperometric data show that in the absence of initial copper(II) ions, the rate of dissolution in the presence of dissolved oxygen is significantly lower. These results confirm that the effective oxidant for the mineral under the conditions of the study is copper(II) and not dissolved oxygen. Coulometric measurements have been used to establish the stoichiometry of the anodic reaction at different potentials.

Jan 1, 2014