Search Documents

By A. C. Halferdahl

The Granby ores may be divided into three groups or classes. The No. I ore is a heavy pyrite, chalcopyrite, pyrrhotite, sulphide carrying some free silica, and calcite. No. 2 ore carries the same general group of sulphides as does No. 1, but in a lesser amount. The gangue is an altered greenstone. No. 3 ore has a smaller amount of sulphides than either of the others. Analyses of these ores is as follows: Cu. Si02 Fe. CaO S. Al 203 MgO No. I. Per Cent. 1.8 17.5 33.0 5.7 34.5 2.3 1.3 No. 2 Per cent. 2. 0 35. 6 23. 9 4. 3 I .5. 0 9. 2 6 .. 0 No. 3, Per cent. 1 . 5 40. 9 21 . 7 3. 0 I 1 . 3 11 . 0 5 . 4 The sulphide minerals in No. 2 and No. 3 ores occur largely in bands in the gangue, and for these portions comparatively coarse grinding serves to release the gangue. Drill cores show a certain dissemination of sulphides in portions of the rock, so that grinding to 5 per cent. + 65 mesh with 65 per cent.-200 mesh liberates the sulphide minerals very completely. The association of the sulphides is fundamental. The pyrite was probably deposited first and was followed by a portion of the chalcopyrite, or these two portions of the sulphide minerals were deposited together.

Jan 1, 1924

Operationalizing the Ruggie Framework in a Mining Context Ruggie?s 3 Pillars: The State?s duty to Protect Policies, regulation, adjudication The Corporation?s responsibility to respect Acting with due diligence to avoid infringing Addressing adverse impacts when involved in abuses Access to Remedy ??even the most concerted efforts cannot prevent all abuse.?

May 1, 2013

By Graham A. Davis, Michael Samis

The dramatic fluctuation in metal and energy prices in the last few years is causing mining companies to consider alternative analytical methods for mine design and valuation. The goal is to improve insight into unforeseen changes in the economic and project environment and to design projects that take advantage of management's ability to respond to these changes. Such flexibly managed projects will contain value that cannot be measured using traditional engineering economic approaches, further motivating the used of alternative, modern valuation methods. This paper considers the valuation of an uneconomic low-grade resource at an open pit gold mine using two of the most popular modern valuation methods, Dynamic Discounted Cash Flow and Real Options. Our analysis demonstrates that the conventional valuation method may incorrectly represent the value and risk attached to mining this type of resource because it is unable to recognize management's ability to respond to future events in a manner that minimizes losses and exploits advantageous business conditions. The results of this paper highlight the importance of recognizing flexibility and business uncertainty in both mine design and valuation.

Jan 1, 2003

By J. F. Henderson

THIS paper relates to an area of more than 5,000 square miles in the Northwest Territories extending north from Great Slave lake and including-the Yellowknife, Beaulieu River and Gordon lake areas. Within the last three years much interest in the area has been created by the discovery of remarkably rich gold-bearing veins and the realization that thousands of square miles of unprospected ground are underlain by rocks like those in which the veins have been found. Probably there were more prospectors in this area in 1938 than in any other part of Canada. The area lies 650 miles north of Edmonton, and 425 miles north of the terminus of the Northern Alberta railway at Waterways, Alberta. The Athabaska and Slave rivers provide an excellent water route from Waterways to Great Slave lake for large oil and wood burning boats and barges which operate from the latter part of May to October. The only portage is around a 16-mile stretch of rapids on the Slave river between Fort Fitzgerald and Fort Smith. The town of Yellowknife, on the north side of Great Slave lake, has sprung into existence during the past year and is the centre for distribution of supplies for the Yellowknife-Beaulieu region. The Con-Rycon and Negus gold mines, which came into production in September, 1938, and February, 1939, respectively, lie about two miles south of the townsite. Excellent airplane service is available from Edmonton to Yellowknife and from Yellowknife to all parts of the area. The prospector and mining operator have come to rely almost entirely on the airplane for supplies and for the transportation of personnel, camp equipment, and canoes from Yellowknife to localities selected for intensive prospecting.

Jan 1, 1939

By I. Spector, A. J. Smith

In 1967, BACM Industries Limited started producing walboard at Saskatchewan's first gypsum products plant, located in Saskatoon, using, as a basic raw material, gyp-sum rock supplied from the company's mine near Amaranth, Manitoba. This paper describes the geology of the Amaranth gypsum deposit, the method of mining the rock and the manufacturing facilities used to produce wall-board.

Jan 1, 1970

By W. M. Tupper

Municipal governments recognize the importance of aggregates in the local economy and the need to manage this resource in the interest of the public good. They have encountered problems with regulating the industry and the dichotomy between the urban need and the rural source. They have suffered from a lack of financial benefit, an adequate aggregate inventory, provincial strategy, economic information and public understanding. A provincial strategy for ensuring the availability of aggregate supplies to developing areas of the Province is essential. The Province should also be responsible for licensing, research, technical expertise on rehabilitation, public education and financial assistance. Upper-tier municipalities (regions or counties) should assume responsibility for resource management, including resource availability, demand characteristics, truck routing, phasing of resource development and sequential land-use planning. Area municipalities (towns and townships) can best determine the social and environmental impact of a specific aggregate development proposal and should therefore have the primary responsibility for the location of new pits and quarries. They should also have the authority to supplement provincial regulations concerning operating standards and the phasing and standards of site rehabilitation.

Jan 1, 1978

The 14MW SAG mill at Tarkwa, Ghana, experienced a frozen drop charge incident on 10 February 2010. This caused downtime of 112 hours, a repair cost of $200k and production loss of 162,000 tons, corresponding to a loss of $8.9M. A new locked charge protection system was installed on the two Tarkwa mills on 30 July 2010, mitigating this risk. This system calculates the ore angle in real time while the mill is starting up and trips the mill if the ore angle exceeds a trip angle setting. The calculation of the ore angle is derived from the mill motor rotor currents only - no mechanical transducers are required. The head of Gold Fields West Africa, Peter Turner, says of the new system: "This is excellent work and the type of technology that has had and will continue to have, major opportunity cost impacts on our business."

Jan 1, 2012

By J. E. McMenamin, R. B. Hall

"With the emphasis in the past decade on larger and more efficient equipment for open-pit operations, the Normandie mine of the Asbestos Corporation has followed the trend, switching from the smaller type of percussion drills to down-the-hole rigs. One 5 Y2 -in. percussion drill is still in use, but is limited to a ""smooth blasting"" role or to the control of the slope on final benches.In keeping with the times, an attempt was made to eliminate, as much as possible, the use of high explosives and to maximize the percentage of ammonium nitrate -fuel oil mixture. As the concentration of ground water increased with increased mining depths, small pumps were initially employed for the dewatering of boreholes. This proved unsuccessful, and a hole-blowing rig was built and a conversion to plastic liners made. The acquisition of a bulk-mix AN-FO truck has permitted the changeover from an AN premix to an ammonium nitrate prill -fuel oil combination at the borehole."

Jan 1, 1966

By PAUL L. DEAN

Industrial mineral deposits are widespread in Newfoundland and Labrador and a variety of commodities are produced. The province has the only pyrophyllite mine in Canada and also produces asbestos, gypsum, silica, barite, limestone, gemstones, cement and other structural materials. Large reserves of these and other industrial minerals are known and several deposits are likely future producers. Most producers are wellestablished and have large tonnages of ore reserves.

Jan 1, 1984

By G. O. Crowell

This paper gives the history of the celestite deposit, now being mined by Kaiser Celestite Mining Ltd., near Sydney, Nova Scotia. Mining and milling procedures are covered, and the regional and local geology of the area are described, including the origin of the celestite.

Jan 1, 1971

By M. J. Young, C. A. Aird

"The Gem molybdenum prospect is situated at the head-waters of Clear creek, between the Fraser river and Harrison lake, about 30 miles north of• Harrison Hot Springs, B.C. Clear creek follows a deeply eroded fault zone southwesterly through the center of the claim group. Elevations range from 2,000 feet in the creek bed up the steep slopes flanking the creek to a height of 5,500 feet. The property lies within an area underlain by schists and gneisses which strike from north to west in a broad fold plunging steeply to the northeast. This metamorphic complex has been invaded by numerous bodies of grano-diorite, much of which is gneissic. A granite plug, roughly 2,400 by 4,000 feet in size, has intruded this broad fold just west of Clear creek and encloses a circular breccia pipe 1,500 feet in diameter. In the breccia pipe, fragments of metamorphic rocks, granite and quartz monzonite porphyry are firmly cemented in a matrix of quartz monzonite porphyry. All the above rocks are cut by numerous fractures filled by vuggy quartz veins, many of which contain molybdenite. Attentien was first drawn to the area by a quartz vein, 18 inches in width, known as the Gem vein, which consists of several laminated bands of quartz and molybdenite. Since 1964, exploration efforts have been directed toward attempting to outline a large, low-grade type of molybdenum deposit."

Jan 1, 1969

By T. C. WEBB

In New Brunswick, significant potash deposits are intimately associated with rocks of the Lower Carboniferous Windsor Group. To date, two deposits high in sylvinite, up to 20 m thick, have been confirmed at depths between 490 and 1,035 m below surface near Plumweseep and Salt Springs. These areas are currently under development by the Potash Company of America and the Denison-Potacan Potash Company respectively. A third area, near Lower Millstream, is also known to contain potash-bearing evaporites and is now being explored by BP Exploration Canada Ltd. All three areas are situated in the western half of the Moncion Subbasin and are within 25 km of Sussex. Numerous similarities in stratigraphy, thickness, mineralogy and structure suggest that deposition of evaporites throughout much of southern New Brunswick was contemporaneous and extended over a considerable area. Future opportunities for potash exploration in the province thus seem excellent. A number of large unexplored areas remain in the Moncion and Cumberland Subbasins and in parts

Jan 1, 1984

Keeping the sediment on the mine site and out of the water course is essential from the regulatory, environmental and sustainability perspectives. Regulation of this aspect of mining is embedded in environmental legislation and government receiving water quality standards, and government control has apparently been considered to be the most appropriate method to define mine site discharge standards and the environmental implications of sediment in downstream watercourses. A literature search for guidelines for the site specific design and operation of sediment ponds treating mine site runoff to remove total suspended solids, turbidity and flocculant-induced toxicity, revealed little information on the mining industry?s and government?s roles in defining the ?how to achieve? related to sediment pond design. Is there a need or reason for an industry-driven leadership to clearly define the ?how to? keep the sediment on the mine site and out of the water course? Currently, this issue is addressed in Canada by a federal mining regulation for metal mines which specifies discharge quality for sediment. This paper focuses on the method used in British Columbia, Canada, to regulate and provide a scientific methodology to control the discharge of sediment from mine sites. Management plans relative to this topic are discussed and are considered to have value from the exploration, construction, operation and the onset of closure phases. In addition, the balance and linkage between the erosion control management plan and the sediment pond management plan are discussed in terms of how they may be designed to complement each other to lower the risk of exceeding discharge and receiving water quality standards. If there were an industry-driven standard, or guidance document relative to addressing sediment release, it would benefit mining companies by eliminating the repetitive analysis of this topic for each new mine, mine expansion, and mine modification; also, government may often replace certain aspects of permitting with a regulation, if there is a government/industry established standard defining Best Achievable Technology (e.g. the Canadian Metal Mining Effluent Regulations).

Aug 1, 2013

By N. Sarmady, Mei Li, N. C. Parson, W. J. Poole

"The mechanical behaviour of AA6082 is a function of the extrusion conditions and in particular, the quench rate after extrusion. It is well known that precipitation of Mg-Si phases on grain boundaries during quenching can negatively affect the ductility of the alloy. In this study, AA6082 alloys containing 0.5 wt. % Mn and 0.15 wt. % Cr were direct chill (DC) cast, homogenized and then extruded to produce 3 mm x 42 mm strips. The microstructure in the as-extruded strips was unrecrystallized due to the Zener-Smith drag from the Mn/Cr dispersoids. It was shown that a solution treatment of 5 minutes at 560°C did not significantly affecting the as-extruded microstructure but if the as-extruded strip was cold rolled prior to heating, recrystallization occurred concurrently with the solution treatment. As such, 3 initial microstructures were produced, i.e. unrecrystallized and recrystallized with a grain size of 9 and 40 µm. After the solution treatment, controlled cooling experiments were conducted using the Gleeble 3500 thermomechanical simulator with cooling rates of 10, 25, 80°C/s as well as water quenched. The mechanical properties (e.g. yield stress, fracture stress and fracture strain) were determined from tensile tests for the different combinations of initial microstructure and cooling rate. The relationship between the quench rate and precipitation of Mg-Si phases on grain boundaries was examined by FEG-SEM. It was found that the yield stress decreased as the cooling rate decreased and that there was complex relationship between the fracture properties and the microstructure.INTRODUCTION As the automotive industry strives to reduce fuel consumption and CO2 emissions with the goal of reducing the environmental impact, there is a need for lighter vehicles. As a result, aluminum alloys are gaining popularity to replace steel parts as structural components. An exemplar of this is the Ford F-150 pickup truck which has an aluminum body and is ˜750 pounds lighter than the previous steel version of the vehicle. The structure includes a mix of aluminum sheet, extrusions and cast alloys. The current research is concerned with the performance of aluminum extrusions in applications such as side rails, crash tubes and other structural parts. These components experience a combination of bending, stretching and folding both during the forming of the part and in service, e.g. crash of a vehicle. There is a need to have detailed information on the influence of processing on final material performance, in particular the cooling rate after extrusion."

Jan 1, 2018

By Tong Gao, Jingyu Qin, Xiangfa Liu, Zengqiang Li, Yaoxian Zhang

"The recycling of aluminum materials is a green industry while Al–Si–Fe is a typical scrap aluminum alloy. The key point of recycling Al–Si–Fe alloys is to separate Al and Fe. A method by introducing Al–Si–Fe alloy into Mg melt has been investigated in this work. A separation layer with gathered Fe–rich and Al–poor Fe3Al0.7Si0.3particleswereobtained at the bottom of the cooled ingot, indicating that ß–Al5FeSi phase evolves to Fe3Al0.7Si0.3,and quantities of Al are released to the upper Mg matrix simultaneously. However, the evolution of Al3Fe by adding binary Al–Fe alloy into Mg melt is different. It is supposed that element Si plays an important role in the phase evolution procedure, thus affects the performance of this method.INTRODUCTIONThe rapid development of aeronautic, automotive and aerospace technologies strongly depends on the consumption of materials while sustainable development is the future direction. Aluminum is a recyclable material and Fe is one of the most common impurities. Fe can be introduced into Al alloys by adding low–purity alloying materials and by using unprotected ferrous crucible, tools, or equipment (Belov, Eskin, & Avxentieva, 2005; Lu& Dahle, 2005).For instance, wear–resistant rings are usually inserted into piston head when producing Al–Si pistons and an infiltration procedure by putting the cast iron rings into Al melt before casting is always essential. As a result, both the re–melting of pistons and the reuse of Al melt for infiltrating rings lead to the enrichment of Fe element, which can be even high to5 wt.%(Viala, Peronnet, Barbeau, Bosselet, & Bouix, 2002).It is widely known that coarse ß–Al5FeSi particles will form in high Fe–contained Al–Si–Fe alloys which is harmful for the mechanical properties. In the past decades, several methods to eliminate the harmful effect of ß–Al5FeSi have been investigated which can be widely referred (Munson, 1967; Lee, Kawamura, Inoue, Cho, & Masumoto, 1997; Suárez–Peña& Asensio–Lozano, 2006; Eidhed, 2008).These methods can be divided into two kinds. One is to aggregate and remove the Fe–rich phase through the methods of centrifugation, gravity filtration or magnetic separation. The other way is modifing the morphology of flake–like ß–Al5FeSi by overheating the melt or adding neutralized elements. However, these traditional methods are rarely used due to respective disadvantages, while the commonly used method in industries is using primary aluminum for dilution. However, only less than 30wt.% of scrap Al can be added into primary Al melt for each melting work while it also results in the decrease of product quality simultaneously(Zhang, Liu, & Liu, 2016)."

Jan 1, 2018

By Guocheng Pan

"Although many factors play roles in the estimation of recoverable reserves, smoothing effect and conditional bias are considered major geostatistical issues in the estimation. This paper introduces measures for smoothing effect and conditional bias, and provides insights into their relation to the estimation of recoverable reserves. Both smoothing effect and conditional bias are intrinsic to the information effect and kriging estimators. For a given level of drilling information, however, it is possible to identify the optimal search radius that minimizes conditional bias. Furthermore, it is also feasible to define variance correction factor for reduction of the smoothing effect from exploration block models. Both of these components are key to the accurate estimation of recoverable reserves. IntroductionThe accurate estimation of recoverable reserves is critical to decision making in different phases of feasibility study and mine planning. Much attention for improving the methodology of estimation has been focussed on the effect of the change-of-support (Parker, 1980; Dagdelen, 1996). For example, it is essential to make a volume- variance correction to the estimate of multiple indicator kriging (Hoerger, 1992). When the size of block, b, in the geostatistical model differs from that of selective mining unit (SMU), v, a volume-variance correction is warranted for the prediction of recoverable reserves.Most mining plans and decisions are made prior to the availability of high density blast-hole samples. In most mining operations, the true SMU grade Zv is unknown at the time of selection. Instead, the selection is based on the estimate Z v**derived from high density blast-hole samples within the deposit G. Nevertheless, the estimate Z v * of recoverable reserves in the stage of mine planning is derived from exploration data. At the end, the production result must be reconciled to the estimate Z v * . In other words, the selection is based on Z v** from blast-hole samples, while the final production figures are reconciled to Z v * from exploration drilling. For a given preselected cutoff grade z0, the actual mining panels will consist of the units having the estimated grade Z v** =z0 rather than the true grade Zv =z0. The difference between Z v** and Zv is usually of less concern."

Jan 1, 1998

By W. J. Wolfe

"THE DETECTION OF BURIED MINERAL DEPOSITS by chemical analysis of vegetation (biogeochemistry) or visual observation of plant cover type (geobotany) is based on fundamentally simple principles. The root systems of vegetation collect aqueous solutions from a large volume of moist ground below surface and act as efficient sampling mechanisms by providing a composite sample of a reasonably large area. These aqueous solutions constitute a source of ore-associated metals that may ultimately be concentrated in the upper parts of the plant. Although certain plant species have a limited ability to break down primary minerals and extract elements, biogeochemistry normally detects only metals capable of moving in solution. Metal concentrations in the underlying soil must therefore exist in a form that is immediately available for uptake by the root systems - generally in the ionic state in aqueous solution or in readily exchangeable form on the surfaces of soil clay minerals. As a result, biogeochemical responses are closely related to variables such as soil pH, Eh, exchange capacity and complexing agents that control metal mobility in the surface environment. In terms of cost, reliability and anomaly contrast, soil geochemistry will normally be more useful than biogeochemistry in locating buried mineralization in regions of residual overburden or thin transported cover. However, in areas where the root systems penetrate thick deposits of transported post-mineralization overburden, plants can provide an effective mechanism of sampling below the transported material. Biogeochemical research in Canada, Scandinavia and the U.S.S.R. has therefore focused on the potential use of plant prospecting methods (1) in areas where the upper horizons of podzolic soils do not provide an adequate response to anomalous conditions under thick deposits of glacially transported till and (2) in widespread regions of peat and muskeg terrain where near-surface mineral soils are absent."

Jan 1, 1971

By Michael R. McPhie

Topics of Discussion 1. The Global Mining Initiative (GMI) and MMSD North America (Brief) 2. Task 2 of MMSD North America ? A Test for Sustainability 3. The Seven Questions and their Application 4. Key Recommendations and Next Steps GMI = Global Mining Initiative Significant international collaborative effort supported by more than 30 of the world?s largest mining/minerals firms which sought to involve all communities of interest. Three major streams of activities: 1. Mining, Minerals and Sustainable Development Project (MMSD) ? 4 regional Process (North America, Southern Africa, South America, Australia) 2. Creation of ICMM (formerly ICME) 3. Major conference in Toronto in May, 2002

May 1, 2002

By E. F. Evoy

"The Gunnar uranium deposit was within metasedimentary rocks of the late Archaen Tazin Group. These rocks were intensely altered by albitization so that the immediate host to the ore consisted dominantly of albite, and by the subsequent introduction of calcite. The ore consisted of disseminated pitchblende and uranophane in a pipe-shaped breccia zone. Oxidation of the ore was more intense near surface than at depth, but there was no near-surface enrichment.IntroductionThe Gunnar Mine site is on the tip of Crackingstone Peninsula, on the north shore of Lake Athabasca, Province of Saskatchewan, Canada. The peninsula forms the southern part of the Beaverlodge mining area. The ore consisted of disseminated pitchblende and uranophane in brecciated metasedimentary rocks of the Tazin Group, and the deposit was characterized by extreme albitization and subsequent carbonatization of the host environment.Production from the mine began in 1954 and the ore was depleted by 1963. In that interval the deposit yielded about 5 million tonnes of ore containing about I. 75 kg/tonne U3O8. It was mined initially from an open-pit and subsequently from underground; the open-pit contributed about 55% of total tonnage. Uranium was recovered by atmospheric leaching in sulphuric acid, ion exchange concentration, and precipitation with magnesia.This paper is based on studies made during the productive life of the mine and is concerned primarily with pre-ore alteration of the rocks containing the deposit, and with the ore mineralogy."

Jan 1, 1986

By W. E. Selnes

Introduction In 1938, a survey conducted by the Ontario Mining Association revealed a rather startling fact. Injuries incurred in chute pulling were more numerous than those from any other single cause. This report prompted Mr. W. B. Paton, then Inspector of Mines for Manitoba, to make a similar survey of the mines of his Province. It indicated that, in Manitoba mines, chute accidents ranked second only to those from falls off roofs and sides. Why has the mining industry been so slow to recognize the dangers of chute pulling? A partial answer may be the lack of any systematic classification of accidents according to their real cause. The result has been to attribute to other causes injuries which were a direct outcome of chute pulling, and, indeed, has made it difficult to analyze accidents in the industry as a whole. Perhaps, too, because chutes are generally located in the comparative safety? of the drifts, there has been a tendency to consider the occupation as not very hazardous. Not until enough statistics were obtained on this particular task could it be appraised correctly. The Mining Association's survey has been most helpful, and latterly the industry has done a great deal toward analyzing the causes of chute accidents and toward determining an effective means of overcoming them. Much, however, remains to be done. An effort will be made in this paper to outline methods which have been found successful in materially reducing the number of injuries. Qualifications of the Chute Puller First of all it must be realized that chute-pulling is a specialized occupation. The men require proper training for the job, just as in other mining operations. Care must, therefore, be taken to choose persons whose qualifications fit them for the job. Chute-pulling is an integral part of the general mining operation and cannot be considered as isolated from the tasks of other workers. One of the essential qualifications of a chute-puller is a sufficient knowledge of mining operations to appreciate the effect his work will have on the safety of others in the vicinity. He must take the necessary precautions, by verbal warnings, by placing barricades and signs, or by personally guarding the chutes, to prevent accidents to fellow workers.

Jan 1, 1947