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By Christian Bourcier

La méthode d?exploitation traditionnelle de la mine est le chantier chambre-magasin. Cependant, lors de l?exploitation d?un chantier, nous avons été confrontés à un problème de soutirage. Le minerai abattu est resté accroché à l?intérieur du chantier ce qui nous obligea à soutirer environ 200 wagons, représentant 700 tonnes. Suite à l?ampleur de la situation, nous avons décidé de finir l?exploitation du chantier par la méthode sous-niveau long trou retraité. Cette première expérience de récupération de piliers ayant été réalisée avec succès, nous avons décidé de continuer avec deux autres récupérations de piliers afin de pouvoir augmenter notre expertise autant au niveau technique qu?au niveau économique.

Oct 1, 2001

By Erwin L. Zodrow

"The neglect of including the toxic metal mercury in the list of escaping elements (Zodrow, CIM Bulletin, September 1982, pp. 138-140) was pointed out to the author in a private letter by J.E. Rehder, dated September 21, 1982. I welcome this opportunity to present my preliminary mercury research data based on coal investigations supported by N.S.E.R.C and the University College.As mercury is a volatile element and liquid at room temperature, special analytical techniques are required to determine concentrations in whole coal. In the investigation, the coal is analyzed by flameless atomic absorption with a lower detection limit of approximately 10 parts per billion, which, however, is a function of the ash contents of the coals (personal communication, J.L. Brooker, XRAL, 1981).Coal seams of the Sydney Coalfield studied so far include: the Point Aconi, a thin shaly coal, the Upper Bonar, an overrider of the Harbour seam, and the Harbour, Shoemaker and McAulay seams, all of which are shown in stratigraphic succession in Figure 1. The seams have been channel-sampled taking 15-cm coal intervals as one sample for analysis. One channel sample has been investigated from each of the seams listed (two channels were taken from the Point Aconi seam), resulting in 38 samples. Table 1 shows the results, which include mercury contents, ash and total sulphur per sample interval. Figure 2 is a frequency distribution of the 38 determinations."

Jan 1, 1982

By J. O. G. Sanderson

THE Brazeau river is a relatively short foothills stream in western Alberta and its drainage area is limited to approximately 2,400 square miles. It rises near the head of the North Saskatchewan river, about two-thirds of the way from Banff to Jasper, and is confluent with the North Saskatchewan at a point about 40 miles north of Rocky Mountain House. It is not the purpose of this paper to describe the geology of all of this area. Only the central portion, which lies east of the outer limestone ranges and takes in the outer folds of the foothills belt, will be dealt with. This area is shown on Figure 1. A small portion of the area described lies in the drainage basin of Pembina river, which flows into Athabaska river. The area to be discussed may conveniently be termed the 'Brazeau area', since Brazeau is the name of the river basin referred to above, of an out-lying limestone range, and of the only large settlement or community in the region, the mining town Brazeau. One of the first Factors of the fur trading post of Rocky Mountain House in the early years of the nineteenth century was Louis Brazeau. Coal mining during the past 25 years, and more recently exploratory drilling for oil, have brought the district into some prominence. The Brazeau area was visited by D. B. Dowling for the Geological Survey of Canada in 1906 and 1907 (1). His traverses and reports dealt mainly with the Kootenay coal deposits. It is doubtful if he traversed the outer foothills area with which the present paper deals. His reports on rich coal deposits in the Bighorn Basin area attracted commercial interests, and in 1908 large tracts were leased as coal lands. James McEvoy mapped and studied the coal seams in that year, and G. S. Malloch, of the Geological Survey of Canada, made a complete survey of the whole of the Bighorn basin. His report (2), published by the Survey in 1911, describes the stratigraphical geology and names the formations. Further references to the geology of the district, mainly in relation to coal, are made by D. B. Dowling (3) and by J. S. Stewart ( 4). In the period between 1913 and 1920, the area was traversed by private interests in search of likely oil structures. A well was started in 1914 along the Saskatchewan river about 19 miles west of Rocky Mountain House, and drilling was undertaken by Imperial Oil, Limited, in 1921 at Coalspur.

Jan 1, 1939

By A. E. Cameron

MR. N. T. AVARD : I would like to congratulate Dr. Cameron on his presentation of some pertinent facts about the Coal Resources of Nova Scotia. There is no question but what there is something very definitely wrong about the coal mining situation in this Province. These are times when we can with profit look facts in the face and attempt to solve some riddles. Perhaps now is the time when we can bring some of these coal mining facts into the open and look them over. Co-operatively, we might evolve some helpful solutions. However, I would like, first, to make some specific reference to the Joggins coal field, not as a mining expert, but rather as an executive who has evolved some ideas after some years of practical contact with this field. Dr. Cameron states that existing operations in this area will probably continue for a few years. As a matter of fact, under normal conditions, these mines are good for another twelve years. With the installation of more powerful equipment for hoisting, pumping, and ventilation, an additional five years could be counted on. With one exception, that pretty well clears up mining from the outcrop, hitherto the only method of approach in this field. The chief reason for this present limitation is prolific 'bootlegging' operations. It is too bad that these should have been permitted to ruin a valuable coal field. Moreover, I am cold by competent authorities that this need not have been so. At one time shortly before war broke out there were 74 bootleg operations within an area of one square mile around Joggins. However, despite the fact that these operations were illegal, I could not find any means of stopping then and I believe the same conditions existed in many other coal areas in the Province. For some reason, the eyes of the law were closed. The result is that many outcrop possibilities have been permanently ruined. The exception noted in the so-called Queen seam, which has definite possibilities for approach through the outcrop. This is probably the best coal in the district.

Jan 1, 1944

By G. Shaw

IN recent years, most of the reconnaissance work of the Geological Survey of Canada has been mapped on a scale of 1 inch to 4 miles. Topographic base maps, commonly made from aerial photographs, were available to the geologist for such work. The advent of war curtailed aerial photography for civilian purposes, and by 1941 all areas already photographed had been geologically mapped. Nevertheless, the need for geological maps to assist post-war prospecting was so apparent, and the country to be covered is so vast, that some new method of rapid mapping had to be devised. It was felt that the need would be met if geological maps could be produced at a scale of 1 inch to 8 miles, provided they were sufficiently accurate in topographic detail to serve as guides to travel. Though in such maps there would be considerable sacrifice of geological detail, they would serve to outline, at least approximately, the major geological units, some of which might prove of sufficient interest to warrant later detailed study. It seemed that such mapping would be particularly useful in the northern regions of Canada which the work of early explorers has indicated are underlain largely by granitic rocks. These, so far as is known, are barren of mineral deposits, but within them are known to be areas or bands of 'greenstones' of the type that, in some localities, have been found to contain valuable orebodies. The problem, then, was to devise a method of mapping, particularly of such greenstone bands, that would make it possible to cover a relatively large area-say 30,000 square miles-in one season and at a cost below that of 4-mile mapping, with, of course, some sacrifice of accuracy. The problem seemed to be threefold: (a) to observe as much of the bed-rock as possible; (b) to produce a topographical map of as much of the area as possible, with particular reference to portions of geological interest; and (c) to cover as large an area as possible in a limited time, which meant faster modes of travel than have hitherto been used. The obvious answer to all three phases of the problem was the use of aircraft. If rock types could be broadly differentiated from the air, reconnaissance traverses by air would supply the answer to the first part of the problem. For topography, air photographs taken on reconnaissance flights appeared to be the answer. For the third phase of the problem, the use of aircraft was ideal.

Jan 1, 1943

By D. Knuutila, G. Goyette, James A. Finch, G. Bartolacci, A. Fortin, Chi Ho Lau, A. Lockhart

"In a COREM-McGill collaborative research and development project, gas dispersion parameters and froth properties were manipulated in a copper flotation plant to study interactions between the collection and the cleaning zones. In this paper, specific work on developing some relationships between operating conditions and froth stability in a rougher column flotation cell of 125 m3 is reported. Froth stability, measured by image analysis, was related to the following process conditions for specific flotation machines in an industrial case study: Gas flow rate, collector dosage, pH, frother type and dosage. Across the range examined, froth stability was improved through a decrease in gas flow rate and/or increasing frother dosage. Metallurgical results (grade and recovery) showed that both gold and copper were dependent on froth stability.INTRODUCTIONMcGill and COREM have over the past two years collaborated in a research and development project to merge gas dispersion parameters, frother analysis (McGill technology), and froth properties (COREM’s imaging system) to study the interactions between the collection zone (pulp) and the cleaning zone (froth). The main goal is to increase knowledge of flotation cell hydrodynamics since it is known to govern the metallurgical performance of the flotation process (Power et al., 2000). In this paper, specific work on developing some relationships between operating conditions and froth stability in a copper flotation circuit is reported.The objective of this work is to study gas dispersion in a large volume flotation column (hydrodynamics) and to measure its impact on the froth. By froth imaging, it is possible to diagnose operational problems on the basis of froth characteristics (Bartolacci et al., 2005a) and consequently, to propose ways of improving process performance by froth analysis (Bartolacci et al., 2005b).Another approach to froth characterization is investigated in this paper. In the same flotation column, a froth stability apparatus (column) was included (Triffet and Cillers, 2004). The mechanical froth stability apparatus is used to link “hard” froth characteristic measurements to “soft” froth characteristic measurements (those obtained by imaging)."

Jan 1, 2008

By Harry F. Weaver

WHEN 1 was assigned by the Director of the United States Bureau of Mines to present a paper at this annual meeting of the Mining Society of Nova Scotia, 1 was grateful, honoured, and elated to realize finally a life-long desire to see your beautiful land and visit with you who have the good fortune to live and work here. Naturally, in preparing for this important event, 1 wanted to give you something of special interest within the limits of the subject so I chose an area dose to my heart -the operation of our Federal coal mine inspection service, which has, as its fundamental purpose, the prevention of accidents in and around ?Coal mines. In 1957 the United States had 10,879 active coal mines scattered throughout 28 States and the Territory of Alaska. The production of coal for the year was about 515,472,000 tons, including 2.5,472,000 tons of anthracite and 490,000,000 tons of bituminous coal and Hgnite. Anthracite is mined principally in a comparatively small area of one State. AU the 28 States and the Territory produce bituminons coal and/or lignite. The beds mined range from 18 inches to more than 100 feet in thickness and from the horizontal to the perpendicular.

Jan 1, 1958

By Mike Robotham

When RFQ?s are received they often contain detailed technical specifications which suggest a departure from the suppliers own customary approach to the design. Both client and end user are quite rightly influenced by their own experiences. The question is who is right, the client and his consultant, the supplier or perhaps a combination of these. This paper looks at some of the fundamental variances that often occur in the approach to the mechanical design of drum hoists, based on our experiences of recent years. Director of Engineering, Mike Robotham is a chartered engineer and has been with DavyMarkham for over 30 years. Having completed a craft apprenticeship he later joined the engineering department as a junior engineer. He has a wealth of experience of working on medium to large engineering projects in the field of mechanical, electrical and hydraulic equipment

May 1, 2011

By R. Biss

"Niobium or columbium, as usually called in North America is becoming a more and more important metal in the industrial world because of its attractive properties.Eventhough discovered in the early nineteenth century, it was not until the 1930's that its use became more widespread. The discovery of large commercial deposits in the late 1950's and the demand of industry for steel with high strength and toughness further promoted its use. To assure its adequate supply new or-e processinr technologies had to be developed. So, beside the traditional gravity concentration, the flotation process was employed for the partial upgrading of pyrochlore concentrate at S8ve (Norway) plant in 1953. The flotation process was equally used at St-Lawrence Columbium plant in the province of Quebec, Canada. The new plants at Araxa and Catalao in Brazil and at St-Honore, Canada, which supply almost of all niobium used today in the non-Communist world, also adopted the flotation process. The processes using long chain aliphatic rnonoarnines, diamines or sulfonates as collectors proved to be difficult especially on weathered types of ores or on those having a substantial content of silicate gangue minerals. They almost completely failed in case of alkaline intrusive rocks as syenites, nepheline syenite, ijolites and pyroxenites, composed almost entirely of silicate minerals. A lot of effort was devoted all around the world on research of new, more efficient flotation processes. So in 1982, Les Services T.M.G. Inc. (Niobec), sole producer of pyrochlore concentrate in North America, developed the direct pyrochlore flotation process from carbonatites. In 1983, at about the same time, the Quebec Department of Natural Resources Laboratories and Les Services T.M.G. Inc. announced a successful recovery of niobium Minera1s from a low grade nenheline syenite ore."

Jan 1, 1984

By F. J. Alcock

IN the summer of 1934, gold was discovered on Lodge bay, on the north shore of lake Athabaska in northern Saskatchewan, about fifty miles east of the Alberta boundary line. The first claims were taken up by the Consolidated Mining and Smelting Company of Canada, Limited, and there was a 'rush' to locate similar showings. Staking continued through the summer and succeeding winter, and in the spring of 1935 the provincial government established a recording office at a convenient point which is central to the more important holdings and where 'planes can land in any weather. During the past summer, the name of this townsite was changed from Beaverlodge to Goldfields, and a post office was established here. The season was one of great activity; a great deal of assessment and development work was carried out and a large amount of further prospecting done. In addition to the work by private companies, geological investigation was carried out in the region by a Federal Geological Survey party under the charge of the writer and a reconnaissance examination was made of an area of some 7,000 square miles surrounding the region of particular interest. Though this was the first discovery of gold in the region it was not the first occasion that prospecting had been carried out along the north side of lake Athabaska. Over twenty years ago, a number of prospectors were at work in the area and a large number of claims were staked, many of which were never recorded. One man by the name of Piché, in the years 1910, 1912, and 1913, took up a considerable number of claims north of Pine Channel narrows, east of Fond du Lac. His discoveries, which consisted of small showings of sulphides in sedimentary gneiss, proved to be of no economic importance. In 1915, a sudden widespread interest was aroused by the report that a sample of ore collected near Fond du Lac had yielded a very high assay in silver. In March and April of that year, prospectors began to rush into the field by dog teams to take up claims, and, as soon as the Athabaska river was free of ice, others started by boat from Athabaska Landing. Some hundreds of claims were staked and recorded in the Dominion Land Office at Edmonton or at Fort Smith. By July, most of the prospectors had? left the region, having failed to find any silver ore. In 1921, considerable prominence was given to the area a few miles east of Goldfields by reports that very large masses of iron ore were available there. Claims were taken up, but the material is much too low grade to be considered commercial ore.

Jan 1, 1936

By Adrian Daniel

"Dating back to 1934, Con Mine is located directly south to the city of Yellowknife in the NWT, Canada. With mill operations ceasing in 2004, a challenging surface remediation situation resulted which required the treatment of close to 40,000 m3 of Arsenic impacted material.Through much of the period of 1941 to 1970, Con Mine treated their refractory arsenopyrite ore through the use of an Edwards Heath roaster. With mounting environmental pressure and through Canadian governmental studies during 1950 to 1970, attention was directed to the Arsenic Trioxide material being collected by two Doyle scrubbers on the Con’s roaster stack. In 1970, the roaster was decommissioned leaving the resulting Arsenic material in two containment areas on surface.As a result of Con Mine entering into remediation in 2004, the Con’s autoclave, commissioned in 1992, was dedicated to the immobilization of high impacted Arsenic material through the combination of excess Iron under high temperature and oxygen overpressure. Examined, herein, is the history and chemistry of the Con Mine autoclave as well as the two stages of chemistry for the Water Treatment Plant used to remove arsenic, heavy metals and WAD cyanide from tailings water. Simplified capping plans of the tailing containment areas and a high arsenic impacted area are also presented.INTRODUCTION TO CON MINECon Mine (Con) is situated just south of the City of Yellowknife in the North West Territories (NWT) Canada and is bounded locally by Yellowknife Bay (North Extension of Great Slave Lake) to the east and Kam Lake to the west (Figure 6). The discovery of gold at Con was made in 1934 and mineral rights were acquired by Consolidated Mining and Smelting Limited (Cominco) and Falconbridge soon thereafter. Nerco Minerals Limited (Nerco) took control in 1986 and in 1993, was subsequently sold to, Miramar Mining Corporation which in turn was purchased by friendly takeover involving Newmont Mining in November 2007 as a result of acquiring the Miramar’s Hope Bay project. Con’s underground operations ceased in September 2003 and have since entered into the remediation of the site. The current surface lease holdings are about 340 Hectares (Table 1) which sits on top of the Archean-aged Yellowknife Greenstone Belt."

Jan 1, 2009

By Gary Anderson

??Privately Held Corporation ??Incorporated in Delaware, May of 2002 ??HQ in Malvern, PA (just outside Philly) ??Approx 40 employees ?9 Field Engineers ?MSHA Certified ?10 Development/NOC Engineers ?Site Survey/Site Design ?RF Engineers ??Standards Based ?IEEE 802.11 ??Commercial Off the Shelf (COTS) ?Gateworks, Ubiquity, Atheros, Linux Based ??Technology was developed and inspired by the lack of communications during the terrorist attacks of Sept. 11, 2001

May 1, 2009

By Goutam H. Shahani

Today, the mining and mineral sectors are being impacted by highly fluctuating supply ? demand, extreme price volatility and tremendous market uncertainty on a world-wide basis. This pattern is expected to continue for the foreseeable future. In particular, large consumers of tonnage quantities of industrial gases (oxygen, nitrogen) all have to make informed investment decisions in this uncertain economic environment. Plant owners ? operators need to carefully examine their current and future industrial gas needs in order to develop the most cost-effective industrial gas plant configuration. This can be done by partnering with an experienced engineering company that offers a complete technology portfolio for producing industrial gases. Ideally, the mineral and engineering companies have to work together as a single team to identify the most efficient and economic plant design. This includes an in-depth assessment of capital and operating costs, in order to deliver an optimal solution, taking plant reliability and process safety into account. It is important to consider all the industrial gas needs at a given manufacturing complex, in conjunction with available utilities and infrastructure to develop the best possible long term solution. Oxygen (O2) requirements include: oxygen enriched and oxy-fuel combustion, smelting and hydrometallurgical operations. Nitrogen (N2) is used for annealing. All of these industrial gas requirements have to be examined at a given site over a long term horizon in a holistic manner. Cryogenic air separation was first practiced at a commercial scale in 1902. Since then, the technology has been constantly refined to reduce cost; and improve reliability and flexibility. Today, using advanced engineering techniques, including proprietary process simulation, and modern fabrication techniques, it is possible to build air separation plants that are both low cost and high quality at the same time. It is important to work with an engineering company that owns a complete portfolio of industrial gas technologies, functional engineering capabilities and a variety of plant solutions. Such a partnership can quickly identify a ?sweet spot? for a given situation. By drawing on experience gained from hundreds of projects, it is possible to quickly optimize a given requirement. In situations where a customer wants a complete solution it may be appropriate to provide an air separation plant on a turn-key basis. This will enable the mining and mineral processor to focus on their core business. By using global procurement and construction capabilities it is possible reduce cost and improve project execution, thereby making industrial gas plant procurement simpler and cheaper for the mining and mineral sector.

Nov 1, 2011

By D. E. M. Plaumann, B. S. Fee, R. D. Hansen, R. R. Klimpel

"The steps from experimental curiosity through to commercial product can be slow and tortuous in spite of the quality of the technological advances offered by the new development. Data generation and interpretation need to be done in lab tests as well as full-scale evaluations and, in each, the advantages of the new reagent must be clearly identifiable and measurable.The Dow Chemical Company has patented a novel new collector for the flotation of zinc. Fl (2-hexylthioethylamine hydrochloride) has several unique structural features that suggest atypical mechanisms for zinc collection. Laboratory data have demonstrated significant flexibility with respect to grade and recovery balance at dosages lower than those typically used for xanthates.In mill trials, the same phenomanon is evident - the choice between high grade and high recovery allows one to select the desired quality of zinc concentrate. One trial in particular was run over a three month timeframe and Fl gave improvements in recovery of 2.5% and a reduction in lead levels with less than 0.5% loss in grade. The dosages of other reagents in the flotation circuit were also reduced.Data demonstrating improved recovery and grade in lab trials will be discussed. Extensive data from the mill trial will illustrate how Fl works in both rougher and cleaner circuits."

Jan 1, 1990

By A. Ignatieff

Introduction Some interest is being shown in Canada in underground gasification of coal and, as developments have now taken place in several countries of the world, it is thought that a review of progress, particularly from the viewpoint of a mining engineer, may be of interest. The literature on the subject, and notably that of Russian origin, is already very voluminous. The various methods of underground gasification of coal have evolved from initial attempts to employ underground workings as gasifiers of previously fragmented coal or to use some method that involves little or no preparatory work underground. The 'stream' method, shown schematically in Figure 1, has been the only one used in tests to date in countries outside the U.S.S.R. Other methods, involving preparatory work underground prior to gasification, are the early 'chamber' method, where fragmented coal was gasified in rooms between inlet and outlet entries, and the underground borehole' method, illustrated in Figure 2, where gasification is developed in a succession of boreholes which are temporarily sealed and then abandoned in turn after gasification. The stream method appears. to be particularly suitable for pitching seems as it is claimed that the pitch prevents ash accumulation or serious blockage from roof falls, and it also aids the circulation of the stream. As a considerable proportion of Canadian medium and high-rank coal seams are inclined, it would seem that, at least at the outset, the stream method or a modification thereof would be the one most applicable to all but the Saskatchewan lignite fields and the flat domestic-coal fields of Alberta.

Jan 1, 1949

By A. S. Bayne

WITH the great increase in the use of power-driven machinery in industry, and consequent large-scale operations, the hazards to which , workmen are exposed have become much more numerous than at the beginning of the century. This is especially noticeable in mining. In the past thirty years or so, improvements in methods of excavation and metallurgy have made possible the exploitation of deposits which would have failed to make ore in previous years. This improvement, together with the in-creased use of machinery, has facilitated the mining of tremendously greater tonnages with a marked decrease in unit cost of production. This 'speed up' in mining creates numerous problems demanding close attention of operators and necessitates careful prep;tratory planning, as well as diligent supervision of actual operations. Underground openings increase in size so fast, and all phases of mining, mucking, and transportation proceed at such a rate, that a short period of reduced vigilance on the part of operators . results in disaster, both from the standpoint of safety and economies. Happily, the challenge of increased hazards has been successfully met by a general application of the slogan 'Safety First'. Today, we have large manufacturing concerns devoted entirely to the development and production of safety equipment for the protection of workmen in various branches of industry. Machinery manufacturers, in co-operation with their mining customers, have included the best possible in foolproof devices in the manufacture of hoists, compressors, boilers, electric motors, and equipment of all kinds. Mining companies and private individuals spend thousands of dollars and devote a great deal of time to research with the single object of preventing accidents and combating miners? diseases. Governments throughout the world have written regulations into their statures for the protection of miners and operators. Staffs are appointed to enforce these laws and investigate accidents to ascertain means of preventing them for the future benefit of the industry.

Jan 1, 1938

By M. Board, R. Pakalnis, S. Seldon, R. Brummer

The Kidd operation mines roughly 10 000 tpd of copper and zinc ore from underground and employs about 700 personnel. In the late summer and fall of 1997, major movements in the proximity of the east wall of the Kidd open pit had been observed. The Kidd pit had been mined from 1965 to 1977 to depths of 260 m (850 ft), followed by subsequent mining by underground methods to current depths in excess of 1830 m (6800 ft). The No. 1 Mine (2600 Level to pit bottom) is approximately 90% extracted, with most of the remaining reserve between 2000 and 2500 levels. Although initial concerns centred on the stability of the pit walls, the potential ramifications of the movements to the underground were recognized and measures were implemented to ensure the safety of personnel as well as to minimize the potential damage to existing operations. In late October, damage to underground operations was observed as deep as the 2000 Level. In the final assessment, the global mobilized mass was a “wedge”-shaped hangingwall block extending from surface to about 610 m (2000 ft) below surface. The “wedge” boundaries are defined by a fault and shear zone which have continuous lengths in excess of 1070 m (3500 ft); its base by shearing through the host rock mass; and its eastern face by deep tension cracks (Fig. 1). Mined and filled excavations at the western face of the “wedge” allowed mobilization of a mass in excess of 30 M tonnes. Movements in excess of 75 cm (30 in.) per day were recorded on the surface stations that preceded the complete shutdown of operations on October 29, 1997. The evaluations in the days following the shut-down were centred on mitigation of immediate and future possible negative impacts on infrastructure and mining of the remaining No. 1 Mine reserves while ensuring the safety of the operators. This effort required the rapid assessment of the potential damage of the block movement on underground infrastructure, stope access, drainage and ventilation, as well as airblast potential due to the falling of a large block into the pit near the ventilation intake at the base of the pit. These assessments were presented in a previous paper (Seldon et al., 1999). In total, the lateral movement of the block on the ground surface was over 4.3 m (14 ft). This paper describes the detailed studies performed to understand the failure mechanism and to assess the impacts on future mining in No. 1 Mine.

Jan 1, 2000

?Why TSM in Canada ?How it was developed ?Architecture and Goverance ?COI panel ?Performance indicators and how they work ?External Verification ?Reporting ?The national organization of the Canadian mining industry ?Mining, smelting and refining of base and precious metals ?Mining of iron ore, diamonds, uranium, oil sands, coal and industrial minerals ?Many associate members ?www.mining.ca

May 1, 2011

By A. G. Doll

"Many power-based grinding models exist, and most operators are familiar with Fred Bond's ""third theory"". Bond's model is most commonly used to describe primary and secondary grinding to product sizes above, for example, 100 µm. Operators sometimes use Bond's equation to describe grinding in situations where it is not appropriate, such as fine grinding below 50 µm. Using an alternative model would be a better choice in this situation.Bond's equation is one in a large family of models. Related equations better suited to fine grinding include the “signature plot”, Von Rittinger's model and Charles' equation. These models have a similar form to Bond's and can be fit to industrial regrind mills and laboratory tests using the simple regression tools in the charts of computer spreadsheets. Operators will find that fine grinding calculations are both easier and more accurate when using the alternative equations to fit their regrind milling surveys or when performing laboratory regrind mill scale-up for plant design.None of these models are new: Charles' equation was published in 1957 and Von Rittinger's model was proposed in 1867. A quick refresh how to apply these equations can turn these oddities from the undergraduate curriculum into useful tools for plant optimization. They can be fit to any type of mill including stirred and tumbling ball mills.IntroductionBuilding a case for fine grind modelling requires reviewing some theory before building a framework for doing fine grinding calculations. The actual calculation procedure recommended is easy and can be applied by plant metallurgists. Don’t be frightened by the theory; the end result is reasonably simple.The observation that mineral breakage is related to the absorption of energy is usually attributed to Von Rittinger (1867). Lynch and Rowland (2005) describe that the ability to empirical test and calibrate energy models of breakage didn’t exist until the widespread adoption of electric motors in the mining industry during the 1930’s and 1949’s. A series of technical papers published by the Allis Chalmers company during the 1940’s demonstrate that they were attempting to do such a calibration using Von Rittinger’s model which is usually stated as: “the energy consumed in the size reduction is proportional to the area of new surface produced.”"

Jan 1, 2017

By Å. Kruukka, H. F. Broicher

The iron ores of the Kiruna mine in Sweden are of exceptional quality except for the phosphorus content in certain zones of the orebody. The prevention of mixing ores high in phosphorus with those low in phosphorus has always been of significant economic importance. The ongoing introduction of tele-mining and automatic haulage by LHDs requires new means in the field of quality control underground, as the experienced miner as well as the underground laboratory assistant no longer are involved in the process. As of 1998, LKAB has been testing prototypes of LIF (laser-induced fluorescence) analyzers for non-contact and real-time measurement of the phosphorus content of ore being transported by LHDs from the stopes to the respective ore pass assigned to a certain ore quality. The principles of the analysis of laser-induced fluorescence, the different test phases and results are described and conclusions made. With bulk sorting of ore underground, the mining engineer supports the efforts of the metallurgist in the processing plant.

Jan 1, 2002