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By James D. Bliss, David M. Sutphin

"On the basis of differences derived from genetic, descriptive, and grade-tonnage data, graphite deposits are classified here into three deposit types: disseminated flake, amorphous (microcrystalline), or graphite veins. Descriptive models have been constructed for each of these deposit types, and grade-tonnage models are constructed for disseminated flake and amorphous deposit types. Grade and tonnage data are used also to construct grade-tonnage models that assist in predicting the size and grade of undiscovered graphite deposits. The median tonnage and carbon grade of disseminated flake deposits are 240 000 tonnes and 9% carbon and for amorphous deposits, 130 000 tonnes and 40% carbon. The differences in grade between disseminated flake and amorphous deposit types are statistically significant, whereas the differences in amount of contained carbon are not .IntroductionIndustrial minerals, including mineral construction materials such as sand, gravel, and crushed stone, have historically exceeded metals in global production value. Today, industrial minerals are being used in new and sophisticated ways in response to the late 1980s emerging information- and service-based economies' requirements for less metal and more industrial minerals . Natural graphite is an example of one such mine ral that has been known since ancient times, and is now finding new applications. Graphite was first used as an industrial mineral in Bavaria in 1400 A.D. where it was an important component of crucibles. Traditionally, natural graphite has been used in heavy industries. New applications, such as development of carbon-magnesite bricks a decade ago and the current advancement of alumina/graphite refractories, are increasing its graphite use. Other new uses for natural graphite, such as the use of graphite powder as a thermal blanket for the continuous casting o f steel (Northern Miner, 1987) and the addition of expanded graphite to polyurethane foam where it acts as a flame retardant (Industrial Minerals, 1987), are increasing the demand for this mineral. To meet future demand for graphite and other industrial minerals, knowledge of the characteristics of the deposit types in which they are found is important. A further look at the deposit types for graphite and at construction of descriptive and grade-tonnage models is warranted .The graphite industry recognizes three basic types of graphite , distinguished primarily on the basis of grain size: crystalline flake, lump and chip, and amorphous. These naturally occurring forms of graphite are products of metamorphism and are found in schists of various types, gneisses, and marbles. Temperatures of at [east 400°C are thought to be required for graphite formation (Landis, 1971). Synthetic graphite, also known as artificial or manufactured graphite, is a man-made carbon product and offers higher purity and lower crystallinity than natural graphite. Several authors have written about graphite's unique physical and chemical properties and the uses for individual types of graphite (Krauss et 01., 1988; Graffin, 1983; and Harben and Bate s, 1984)."

Jan 1, 1990

By S. Fuentes, J. Cáceres

"During the past fifteen years, mines utilizing the block caving method have improved performance and systematically reduced total mining costs.This paper describes improvements in mine design, mine planning, and mine management, including methods enabling the Chilean and international mining industry to ensure cost savings and productivity growth while using the block caving method. These improvements have encouraged the re-evaluation of underground operations at operating and closed open pits, and challenge surface mining applications as the only low-cost mining method. This paper describes a strategy to estimate the optimum open pit to underground transition time during the life of a mine. IntroductionDuring the last fifteen years, block caving mines have experienced huge changes in designs, planning and administration. These changes have permitted operators to drastically reduce costs, improve equipment productivity, and improve overall business performance. As a consequence of this situation, the block/panel caving mining system is challenging actual open pit operations to maximize the net present value (NPV)."

Jan 1, 2004

By L. A. Wrigglesworth, A. S. Dadson

The orebodies of the Giant Yellow-knife mine occur in zones of schist, in an assemblage of typical Precambrian greenstones which form part of the Yellowknife Greenstone Belt. One of the most interesting problems at the mine concerns the fold-like attitudes assumed by the schist zones. The internal structure of the zones and orebodies provides much evidence of folding. A logical conclusion would be that the zones represent a single horizon which has been folded and drag-folded in the ordinary course of mountain building. However, surface mapping, and correlation of certain marker horizons, in underground work, indicate a homo-clinal succession of steeply dipping flows. If this concept of the geology is correct, the zones must cross-cut the regional strike at a small angle and, in the over-all aspect, the regional dip at a large angle. A mechanical interpretation of the zone structure is presented as a suggestion for the present until new evidence is found.

Jan 1, 1959

By D. Emadi

The ASTM B108 Mould and a Modified Mould were used to cast test bars under a variety of conditions: mould and pouring temperatures, mould coating and tilt. Mechanical properties were determined in the as-cast and heat-treated conditions. The ASTM Mould is less sensitive to casting variables. Enlarging the gating system and adding additional gates to the ASTM mould can improve properties in the tilt position. The reproducibility of properties in as-cast and T6 heat treated bars was investigated.

Jan 1, 2004

"Polycom, a new approach to ore processing based on pressure comminution, is obviously a very attractive alternative to conventional processing methods.Since a full-scale pilot plant was commissioned in 1986, more than 125 commercial installations, with capacities up to 1000 t/hr, have gone ahead.Already successfully used in processing cement clinker, limestone, coal, and other minerals, Polycom high pressure grinding results in:o Significantly reduced capital costs, because smaller units can be used m new installations;o Capacity increases of up to 100% in existing facilities; and o Operating economies that include energy savings of 20% or more, and reduced wear parts consumption.1. IntroductionAutogenous or semi-autogenous mills in conjunction with rod or ball mills are used with preference for ore processing. Most ball mills are of closed-circuit design and operate with mechanical classifiers (spiral or rake classifiers) or hydrocyclones. In other words, the ores undergo wet primary grinding, since slurries are required for the downstream separation stages anyway. This paper presents a new grinding system based on high pressure comminution of ores. This grinding process allows:- Energy savings of up to 20 % or more- Capacity increases of up to 100 % and more- Reduction of wear costs- Smaller units for new installation and thus- Reduced investment costsThese advantages are highly interesting for both new installations and conversion projects, particulary in cases where an increasing hardeness of the ore, i.e. rising Bond Work Index, reduces the output of the plants or where the metal assay of the ore decreases and the capacity of the existing systems has to be increased. POLYCOM high-pressure grinding rolls have established themselves with great success already for grinding cement clinker, granulated blast furnace slag, limestone, cement raw materials, coal and other materials.Meanwhile more than 250 high pressure grinding rolls have been installed worldwide. Capacities up to 1.000 t/h with roller diameter up to 2.8 m and drive units up to 2.400 kW are installed."

Jan 1, 1991

By Persio P. Rosario

Crushing has proven to be of fundamental importance in mine mill integration at Highland Valley Copper (HVC). Highland Valley Copper has achieved large throughput and good quality control through the gyratory crushers by proper blast design and better gap control. The next step, in optimizing the mine mill relationship, is evaluating the crusher liner wear and its shape influence on performance and product size reduction. To do this a laser measurement device has been developed and data is being recorded on the concave and mantle liner wear. This paper will outline the work to date and indicate specific objectives of the work.

May 1, 2002

By George F. Bassett

"More will be expected from the mine or metallurgical plant electrical system in the late 70's and 80's in terms of energy conservation, reliability and fire prevention. Increased electrical loads 1•equired by larger arc furnaces, higher-horsepower motors for mine hoists and pollution control fans, and greater use of electrical heating will have to be supplied. Computers and sophisticated instruments will be used more extensively and have less tolerance for electrical fluctuations. More extensive control and monitoring systems will be required to increase production and minimize operating and maintenance costs. Changing energy costs will prompt design engineers to investigate in-plant generation, particularly where sites are remote from existing utilities lines or steam from turbines may be used in the process. Some utilities are requiring industries to increase their power factor to above 90% ; others are requiring stricter control of voltage flicker from arc furnaces and harmonics from rectifiers. There is a trend to AC with solid-state cont1•ols instead of DC for large cranes."

Jan 1, 1976

By D. A. Ainsworth

"The first known use of activated carbon dates back to the Ancient Egyptians who utilized its adsorbent properties for purifying oils and medicinal purposes. Centuries later, the early ocean going vessels stored drinking water in wooden barrels, the inside of which had been charred. (However, by modern definition the carbon used in these applications could not truly be described as activated.) By the early 19th century, both wood and bone charcoal was in large scale use for the decolorization and purification of cane sugar.However, it was not until the beginning of the First World War that the potential of activated carbon was really capitalized upon. The advent of gas warfare necessitated the development of suitable respiratory devices for personnel protection. Granular activated carbon was used to this end as, indeed, it still is today.By the late 1930's there was considerable industrial scale use of carbon for both gaseous and liquid phase application and new manufacturing processes had been developed to satisfy the needs of industry. During the 1939-1945 war, a further significant development took place - the production of more sophisticated chemically impregnated carbon for the removal of both war and nerve gases."

Jan 1, 1984

By B. Goard

"IntroductionCemented backfill has been placed underground in slurry form in Inco Limited's Ontario Division mines since the early 196Os. The slurry was traditionally mixed on surface at between 65 and 70 wt% solids* and transported underground via gravity through a borehole-pipeline distribution system. This method of placement, while simple and dependable, has proven to be costly because of the large amounts of transport water involved.A significant quantity of the slimes buildup on mine levels is caused by the backfill water carrying cement and other fine material out of the stopes. The level cleanup and eventual pumping or hoisting of the slimes and water back to surface result in substantial indirect backfilling costs.The cement that remains in the stope is always overhydrated because of the high water cement ratios that exist. As a consequence, high concentrations of Portland cement must be added to the backfill to produce the fill strengths required for the different mining methods.Pouring backfill at these densities also demands extensive fill preparatory work in the stopes to withstand the hydraulic heads created by the slurried fill. This, along with the delays in pouring necessary to allow for water drainage, result in significant losses in productivity.These negative aspects of slurry placed fill has led Inco Limited to investigate several methods of transporting backfill underground via pipeline, at higher densities (i.e. 75 to 95 wt.% solids). Three separate transport methods are presently being experimented with by the Company's Mines Research Department. Each utilizes a different technique or form of flow transport, i.e. concrete pumping technology, high density slurry flow, and pneumatic conveying."

Jan 1, 1987

By Iwueze Anaekperechi Rose

The International Labor Organization has declared mandatory adequate provision of safe workplace and safety for all workers in all occupations including the mining sector. Early scientists like Agricola (1559) who studied the health of Miners, found that there are peculiar health problems associated to their work and working environment. This unsafe working condition was one of the major factors that resulted to the Industrial revolution in England and eventually led to the establishment of regulations and laws guiding operations in all workplaces and workers in England and all over the world. Recent studies by Heinrich suggested chains of events of safety issues in the mining sector. Occupational injuries, accidents and ill health have huge social and economic implications on workers, their families and communities. Top mining top issues are respiratory diseases, noise, explosives, ventilation, fire, and explosion. However, one of the principal mechanisms for achieving Occupational Health and Safety (OHS) goals and mapping the future is government regulations of employers. In Nigeria, the situation is not different; mining operations are equally hazardous and have far reaching implications. In 1995 the Ministry for Solid Minerals was established to focus on the development of other categories of mineral products ranging from gold, coal, uranium, and tantalum deposited across the country. Prior to this an Act of Parliament Act Cap 121 of 1946, was in place to regulate amongst other contents mining safety. This was subsequently reviewed following the incidence of Lead poisoning resulting from small scale miners processing gold ore highly contaminated with lead in Zamfara state (northern Nigeria). Hundreds of children died as a result of exposure to lead poisoning, it was clear that the regulations were not sufficient (details to be discussed). However, advances have been achieved in mining engineering since then. A review team was constituted to provide a more stringent law to regulate mining operations in Nigeria. The strategies for mapping the future of OHS in mining engineering will employ amongst others setting and adopting ISO/ILO standards and enforcement; providing technical assistance; and establishing sustainable developmental structures as surveillance and compensation. The management systems approach was also developed as a result of cases of accidents. The accepted international standards guidelines and requirements will be proposed. Furthermore in mapping the future for Mining Engineering, it is suggested that most countries have their own management strategies and legislation to improve safety of workers through greater consistency and efficiency of OHS programs. Some American researchers came up with the Safety Engineering Model. The Australian Mining Council of mineral and petroleum resources after the Catastrophic Maura Disaster developed the National Mine and Safety Framework. In Canada, after the Hillcrest mine disaster in 1914, Allan shaft coal mine catastrophe in 1918, Westray mine explosion in 1992 and other disasters, Occupational Health and Safety Act R.R.O 1990 was sufficiently developed to provide adequate safety conditions and standards. In Nigeria after the disastrous Zamfara lead poisoning, which claimed the lives of hundreds of children due to exposure and lack of appropriate safety measures, stringent measures were developed by the federal ministry of Justice to address and regulate mining process in Nigeria.

Aug 1, 2013

By L. D. Smith

"This paper examines the impact of the various assumptions that go into an economic evaluation, and shows how these can be combined to show an exciting result that may not really exist. An example of an embellished case (the kind that one frequently sees when projects are being promoted) is developed and the cumulative impact is analyzed to show the actual project underneath. The paper also points out some areas to watch for overly optimistic assumptions such as prices, inflation, and debt. The concept of a “bare bones” base case is proposed (constant metal prices, constant dollars, no inflation, no debt, no interest, on a project basis, after tax) as a common reference point.As well, the discount rate is examined as one of the fundamental means of reflecting risk in discounted cash flow evaluations. Current industry practice is discussed, and a methodology for the analysis of risk levels is proposed that assesses the constituent components of the discount rate: real interest, mineral project risks, and country risk."

Jan 1, 2002

By Jason J. Crowder

Presentation Outline ? Introduction ? Costs of ground support and rehabilitation ? Why post-failure rock mass properties are necessary ? The Rock Mechanics Problem ? Present State of Modelling and Instrumentation in Mining ? Case Study Background ??Williams Mine ? Deriving Parameters for Modelling from Instrumentation ? Results from Case Study ??Back Analyses ? Discussion of Research Impact t Summary

May 1, 2006

By Pavel Vasak

The Laurentian University Virtual Reality Laboratory (VRL) has provided a unique platform for the development and testing of novel seismic and microseismic data processing and visualization technology. In collaboration with Vale?s Creighton Mine, the technology was implemented at the mine site and consists of a VRL system and site calibrated Seismic Excavation Hazard Map (SEHM) software. The SEHM was developed as a practical solution for the mine operator to identify areas of elevated, active rock mass damage processes caused by recent mining activity. This paper is a pictorial representation of the 3D stereoscopic demonstration of the Creighton Mine seismic data distribution and interpreted SEHM for the first quarter of 2009. A live demonstration is scheduled at the Laurentian University VRL as one of the conference field trips. The demonstration highlights the technology transfer of research concepts into a near-real-time excavation hazard system that utilizes the key aspects of virtual reality technology; the ability to integrate large datasets (geology, mine excavation, (seismic) monitoring data, production scheduling, stress model, etc.); the ability to manipulate and visualize large datasets in both space and in time (mining sequence); and the ability to review the datasets by a group of experts in an immersive (3D stereoscopic), collaborative environment to better understand the processes and context of the mining-induced seismicity and evaluate potential risks to the mining operation.

Oct 1, 2010

By J. Janzen

The cost to supply ventilation may exceed 40% of the total mine energy cost for underground mines and is often higher for deeper mines. The goal of Ventilation-on-Demand (VOD) is to ensure that the required quantity and quality of air is supplied to underground mining crews and diesel equipment at the least energy expenditure (minimum cost). A VOD system may include control of surface fans (Supply & Exhaust), underground booster fans, auxiliary fans and automated regulators/dampers to regulate the flow of air with more control elements providing more value. Strategically located Air monitoring stations measure air quantity and quality and provide feed-back enabling control. The modular design involving controls, intelligent instrument and intelligent motor control centres coupled with a communication network allows the quick installation, commissioning and expansion of the system as the mine develops. The result is a very robust, flexible system while reducing maintenance costs and spare parts. This paper discusses the impact of sensors, installation and commissioning on advanced controls and provides solutions for in-field applications.

Aug 1, 2013

By Karim El-Ouassiti, Marc Minville, Stéphane Chabot, Claude Bazin, Valérie Ouellet

"Alumina is the main source of aluminium and it is extracted almost exclusively from bauxite ores found in the Southern hemisphere. Clays are abundant minerals that contain from 15 to 40% w/w of alumina from which it can be extracted by various processes. This paper reviews the processes used for the extraction of alumina from clays and discusses results obtained with a clay sample from the Murdochville area in the Quebec Province. The application of a conventional process to this clay did not yield an acceptable recovery although smelter grade alumina was produced. A modification to the process allows increasing alumina recovery from 85% to more than 92%. The application of the improved flow sheet to other alumina carriers failed to yield comparable recovery, showing that an optimum processing path for the recovery of alumina should be found for individual clay materials.INTRODUCTIONMost of the aluminium smelters are fed with alumina extracted from bauxite found in the Southern hemisphere. Bauxite is processed by the Bayer process that uses a caustic leach of the ore. In the middle of the century, the US Bureau of mines, motivated by the fear of an alumina delivery disruption, conducted several research projects aiming at producing alumina from non bauxitic ores. These projects led to the development of various acid leaching processes (Habashi, 1993). The sulphuric and hydrochloric acid leaching processes were brought to pilot plant evaluation (Bengtson, 1979), while nitric and other leach liquors were tested in the laboratory (Phillips and Wills, 1982; Habashi, 1983). Although clays are abundant and inexpensive minerals, the studied processes remained uncompetitive with the alumina extraction from bauxite (Hudson, 1987 page 42; Peters et al., 1962) for which reserves are estimated to support alumina production for the next 50 years (Oye et al., 1999). On the other hand, the local extraction of alumina from clays could significantly reduce the transportation costs of alumina to smelters and provide an alternative source of alumina supply from the Southern hemisphere countries. Also, the extraction of secondary products for some types of clay (Nasyrov et al., 1999) containing significant amounts of potassium and sodium could provide an additional return that may improve the economics of alumina production from clays."

Jan 1, 2005

By R. L. Bailey

"The Acheson D-3 Pool was discovered in August 1950, and contains 88 producing oil wells on 40 acre spacing. Initial oil-in-place was 118 million stock tank barrels and initial well potentials averaged 2,000 barrels per day.In early 1956 studies of hydraulic interference between the Acheson and Leduc D-3 Pools were conducted on the Carter Petroleum Reservoir Analyzer. These studies indicated that the natural water drive to Acheson would be incapable of replacing reasonable withdrawal rates over the life of the pool. To avoid shrinkage losses a scheme of pressure maintenance by water• injection was therefore instituted in March 1957.This pressure maintenance scheme is notable because pressure is being effectively maintained by high volume injection through one well located on the flank of the pool. Close control on reservoir behaviour is maintained by regular bottom-hole pres-sure surveys and observation of water cuts on producing wells. No evidence of pressure gradients or channelling of the injected water has been observed to date, and the water-oil contact has remained level over the whole field. It is possible to control the average reservoir pressure within very close limits by varying the rate of fresh water injection.Ultimate recovery estimated from the rise of the oil-water contact and calculated water influx to December 31, 1958, is 335 barrels per acre foot, or a total of 91.4 million barrels from the pool. This compares to 217 barrels Per acre foot or a total of 59.4 million barrels indicated from laboratory test data."

Jan 1, 1961

By K. G. Thorne, M. J. McLeod, D. Hoy

"Throughout the Paleozoic, a variety of gold depositional environments were created in the New Brunswick segment of the northern Appalachians because of the complexity of arc and continental plate collisions and subsequent erosion of the orogen. In southwestern New Brunswick, recent exploration and research has focused on deposits and occurrences that can be broadly classified as intrusion-related, generated by late- to post-orogenic felsic to intermediate plutonic rocks emplaced during the Early to Middle Devonian. This work has led to the establishment of models for gold mineralization and guidelines for exploration in this area, which might also be applicable elsewhere in the southern part of the province and, perhaps, throughout the northern Appalachians. The deposits in the vicinity of Clarence Stream in southwestern New Brunswick exemplify this deposit type, and highlight the emergence of a possible major gold district in the region. Durant le Paléozoïque, une grande variété d’environnements aurifères ont été créés dans le segment néo-brunswickois des Appalaches du nord en raison de la complexité des collisions entre arcs et plaques continentales ainsi que durant l’érosion subséquente de l’orogène. Dans le sud-ouest du Nouveau Brunswick, les travaux d’exploration et de recherche récents se sont tournés vers les gisements et les indices appartenant à la classe des gîtes associés aux intrusions, générés par des roches plutoniques felsiques à intermédiaires tardi- à post-orogéniques mises en place au Dévonien précoce à moyen. Ces travaux ont permis d’établir des modèles de mise en place pour la minéralisation aurifère ainsi que des guides d’exploration pour ce secteur, lesquels pourraient aussi être appliqués ailleurs dans le sud de la province et, possiblement, dans l’ensemble des Appalaches du nord. Les gîtes aux environs de Clarence Stream dans le sud-ouest du Nouveau Brunswick sont un exemple de ce type de gisement, mettant en valeur ce qui pourrait devenir un district aurifère majeur dans la région."

Jan 1, 2008

By M. J. deBastiani

The uranium producing division of Denison Mines Limited operates a 6,000-ton-per-day integrated mining unit in the Algoma area of Ontario. The property is located approximately one and one-half miles from Highway I 08, eight miles north of the town of Elliot Lake. The property was staked in 1953, diamond-drilled in ?late 1954 and 1955, and put into production in 1957. Since that date, the operation has produced $250,000,000 worth of uranium oxide from approximately 11,000,000 tons of ore milled, and paid $18,000,000 in dividends to its shareholders. The operation employs about I000 people, and monthly operating costs are approximately one million dollars. From these figures alone, it is obvious that it was necessary to develop and institute an adequate set ?of controls for effective management at all levels of supervision over a period of four years, a system of production and cost control was developed that enables us to effectively measure the pulse of the various phases of the operation at any given time.

Jan 1, 1963

By W. M. Brewer

Introduction This paper describes some of the mineral resources that are tributary to that portion of the Pacific Great Eastern railway included in the Western Mineral Survey District, No. 6, of British Columbia. This district extends 38 miles northerly from Squamish, the ocean terminus of the railway at the head of Howe sound, to Alta lake. Beyond Alta lake the railway continues northerly through two other mineral survey districts: the Central Mineral Survey District No. 3, and the Northeastern District No. 2. District No. 6 includes that section of the Coast Range from which the waters flow southerly towards Howe sound. The division between District No. 6 and District No. 3 is represented by an imaginary line across the summit between the headwaters of the Cheakamus river, flowing south into the Squamish, and the Green river which flows north and empties into the head of Lillooet lake near Pemberton meadows, about 20 miles from Alta lake. History: - The history of the route of the P. G. E. railway dates back to the old Cariboo days when a pack-horse trail traversed the country northerly from Squamish to the Pemberton meadows, and also south-easterly from Squamish to the head of Seymour creek, thence southerly down that creek to the north arm of Burrard inlet.

Jan 1, 1925

By V. C. Pandolfelli, L. Paulino, C. E. Zangiacomi

The continuous improvement in aluminum industry over the last years has increased metal output at lower cost. The potlining plays an important role in this regard due to high cost involved and more recently in its environmental aspects. In order to increase potlife and thus minimize the aluminum cash cost, a systemic approach is needed, through investigating the main cathode failure mechanisms by using a pot autopsy as a powerful tool, and then making the necessary chances to achieve extended potlife. In addition, preheating and pot start-up may also damage the cathode if not performed with an appropriate technique or even if the lining materials are not specified correctly, among other factors. All these aspects will be presented and discussed in this paper. Increased potlife, especially now that the current is reaching values up to 300kA, will allow aluminum plants to match their goals more efficiently at lower costs.

Jan 1, 2006