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By P. Marcotte, G. LeBlanc, S. Ouellette, J. Boutin

"To characterize noise and vibration sources of different types of mining equipment used in underground mining, the authors performed a study in eight Quebec mines on 28 pieces of equipment. This paper presents the procedure followed to select the equipment to be evaluated, and the low-cost acquisition system developed to perform multichannel time-domain data acquisition in harsh environments. It also presents the results obtained for the noise level produced by the equipment and for handarm and whole-body vibration exposures.RÉSUMÉ Dans le but de caractériser les sources de bruits et de vibrations de divers équipements miniers utilisés sous terre, les auteurs ont étudié 28 équipements dans huit mines du Québec. L’article présente la procédure suivie pour choisir les équipements à évaluer ainsi qu’un système multicanal à faible coût développé pour acquérir des données dans des environnements difficiles. Il présente aussi les résultats obtenus pour les niveaux de bruit produit par les équipements et pour les expositions main-bras et du corps entier aux vibrations."

Jan 1, 2015

By J. J. Baz-Dresch

"The Cannon Mine, a joint venture between Asamera Minerals (the operator) and Breakwater Resources, is located in the centre of Washington state at the eastern base of the Cascade Mountains. The mine complex is located three blocks south of the city limits of Wenatchee, part of an urban area with a total population of 47 000. The closest residence is 350 feet from the mine portal.The B-Neath zone is a narrow, high-grade, downward extension of the southern tail of the mine's main ore body, the B-North zone. It also underlies the northernmost portion of the B-West zone (Fig . I) . The ore is usually reasonably competent but completely surrounded by very weak rock consisting of shear zone and unsilicified sandstones and siltstones.The zone has maximum dimensions of 420 ft in thickness, 500 ft in length , and 200 ft in width . The economic reserves extend from the 70-ft elevation (elevation above sea level) to the 630-ft elevation and consist of about 1.3 million tons of geologic reserves (proven and probable) at an average grade of 0.33 ounces per ton.Acquisition and ExplorationInitial DiscoveryThe initial discovery of the B-Neath zone was made by Tenneco Minerals during July through September, 1984. Their 22-hole surface drilling program consisted of 18 200 ft of drilling. Tenneco Minerals had acquired the 91/2 acre lease from United Mining Corporation.Asamera Minerals subsequently purchased Tenneco's lease in July, 1985; Tenneco retained a royalty position which was later purchased by Echo Bay Mining.Follow-up drilling by Asamera Minerals consisted of both surface and underground drilling. Eight surface holes (7200 ft) were drilled commencing in December, 1985. Following evaluation of the geologic data, an access drift was driven on strike along the top of the ore zone on the 500 level. Diamond drilling from this platform consisted of 17 200 ft in 79 holes."

Jan 1, 1990

By K. C. Corin, M. S. Manono, J. G. Wiese

Depressants play a crucial role in the flotation of PGM bearing ores as they prevent naturally floatable gangue (NFG) from reporting to the concentrate. This action is regarded as critically important because less dilution of the concentrate means lower costs for downstream processes. However, abnormal water conditions (such as high concentrations of ions) in the flotation system can modify the selectivity of these depressants. It is well known that the existence of selected electrolytes in water can alter the behaviour of some polysaccharide depressants by enhancing their adsorption onto gangue minerals and thereby prevent naturally floatable gangue from moving into the froth phase. Concurrently these same electrolytes may enhance frothability, owing to their stabilising effect on the bubbles within the system. Plant water at various ionic strengths was investigated against depressant type and dosage in order to understand electrolyte-depressant interactive effects during the flotation of a Merensky ore, using entrainment, rate of NFG recovery, and total gangue recovery as proxies. The study showed that the rate of NFG recovery per unit mass of water decreased with increasing ionic strength at all dosages, however the total amount of gangue reporting to the concentrate increased with increasing ionic strength at all depressant dosages. Thus, this paper attempts to consider the effects of both ionic strength and depressant dosage as individual factors within flotation. It further looks to investigate whether any interactive effects exists between these two factors when considered simultaneously.

Jan 1, 2016

By Adam Moore, Ryan Gillespie, Jarrett Quinn, Audrey Walters, Peter Radziszewski

"Vale Long Harbour Processing Plant (LHPP) was designed to process Voisey’s Bay nickel concentrate into finished nickel and associated copper and cobalt products. The plant includes a secondary grinding circuit comprising two Stirred Media Detritors (SMDs) operating in parallel. The ultrafine grinding circuit was designed to process concentrate at a rate of 33 t/h and produce a ground product (P80) of 20 µm to feed the leach circuits. Start-up of the grinding circuit at LHPP was undertaken in December 2014.The objective of this paper will be to describe the design, commissioning, start-up and performance of the secondary grinding circuit with a focus on the two Metso SMD-355-C mills. Following a brief overview of Vale’s LHPP and the SMD technology, the paper will review the design of the SMD secondary grinding circuit from lab tests through to scale-up performance prediction. This will be followed by the results of circuit commissioning outlining some of the issues raised and addressed after which SMD performance will be outlined. Specifically, the SMD circuit grinding performance will be examined since start-up which will include the effect of media size and wear on grinding. Furthermore, impeller wear will be examined by determining initial “shear volume” and worn “shear volume” as well as its effect on mill power and the means to maintain it. The paper closes with a discussion on grinding performance."

Jan 1, 2016

By C. S. Parsons

Introductory The steady advance in the price of lead and zinc in the metal markets of the world during the past few years has resulted in an active search for new deposits of these metals, and to the re-examination of known properties that are now idle. There are a number of deposits of these metals in eastern Canada, the best known of which are the Tetreault mine at Notre Dame des Anges, Que.; the Reader mine on Calumet island, Que.; the Stirling property in Cape Breton, and the Federal mine in Gaspe district, Que. . The author has run concentration tests on the ores from the first three mentioned properties. The ores from Notre Dame des Anges and Calumet island presented problems in concentration which were not successfully solved until the past year. Although considerable experimental work has been done by the Ore Testing Laboratories on the ore from the Stirling mine we have not been successful in developing a satisfactory method of treatment. Character and Types of Ores Metallurgically the lead-zinc ores of eastern Canada may be classified into three distinct types as follows: First: - Ore in which the sulphide minerals are fairly coarsely crystalline and can be freed by crushing to 40 or 60 mesh. The zinc blend has a high iron content (not marmatite) and gives a dark brown colour on grinding. The ores of Notre Dame des Anges and Calumet island, Que., may be cited as examples.

Jan 1, 1925

By C. M. Campbell

THE dire effects of rapidly vanishing natural resources, widespread unemployment, and increased debt and taxation in recent years have challenged Canadians to produce a practical solution to these national economic problems. In more recent months, wars and rumours of war have indicated, among other things, the need for better control of our mineral wealth. The erection of a smelter on the lower mainland coast of British Columbia, treating all Western ores, and such ores as it will be found advisable to import, will make an important contribution toward a solution of these problems. It is believed that the ores tributary justify a smelter of major proportions. A stock-taking to confirm this can be made with reason-able accuracy in a short time, and this should be undertaken without delay. Enough general information is, however, available .in this paper to justify the technicians of the Department of Mines at Ottawa and of interested smelting companies making a preliminary study of the matter. THE DEFENCE ARGUMENT As a factor in rearmament, metals play a vital part. That rearmament is to continue on an increasing scale is indicated in Premier Chamberlain's address of October 3rd last, when he said: ?'For a long period now we have been engaged in this country in a great programme of rearmament which is daily increasing in pace and volume. let no one think because we have signed 'this agreement between the four powers at Munich we can afford to relax our efforts or call a halt in our armaments at this moment'. As matters stand, the facilities in British Columbia are entirely out of line with the strategic importance of this Province as the Western Front of Canada and the Empire. All our copper ores, and an appreciable part of our lead and zinc ores, are sent for treatment to Japan, United States, and Europe, while we import our iron and alloys. A treatment plant on this Coast would not only give us control of war metals and chemicals but it would provide an increased industrial and research population, badly needed in this area and of the greatest value in the case of war. This is where the mining industry can do its bit.

Jan 1, 1939

By D. H. Ryan, J. T. Graham, A. Navarra, J. A. Finch, S. Somot

Pyrrhotite (Po) is widely considered to be the most significant mineral in the self-heating of sulphides. It is therefore desirable to determine the amount of Po in mineral samples. This is commonly accomplished through x-ray diffraction (XRD) or quantitative evaluation of materials by scanning electron microscopy (QEM-SEM). This paper introduces another quantitative method based on Mossbauer analysis that requires limited sample preparation and has the additional potential to detect the sulphur/iron ratio within Po. The technique is explored using pentlandite/pyrrhotite mixtures.

Jan 1, 2009

By L. M. Wang, G. P. Jiang, Y. Jiang, Liao. W. S.

ABSTRACT The authors measured porosities and permeabilities for cores from a low-permeability sandstone uranium deposit in Inner Mongolia. Features studied included fine pore structure, mineral composition, cation exchange capacity, granule appearance, and cementing features. In general, grading of the grains was relatively poor, which decreased the radii of the pore channels. The pore throat distribution was significantly heterogeneous. Pore channels ranged from small to large, but the lack of large pore channels led to low permeability. Cementation by calcite and clays, including montmorillonite, chlorite, and kaolinite, resulted in pore channel narrowing, further decreasing the permeability of the formation.

Jan 1, 2014

By W. Dong

This paper presents the fundamental study of the temperature distribution in a reforming planar solid oxide fuel cell (SOFC) using mathematical modeling and experimental testing approaches at Versa Power Systems (VPS). In order to investigate the on-cell temperature distribution under high rates of Natural Gas direct internal reforming (DIR), both the computer simulation approach and the experimental testing approach have been developed. In this work, comprehensive in-house DIR and SOFC models were developed and employed for the computational fluid dynamics (CFD) based 3D computer simulation. The current SOFC module has been corrected to take into account both the on-cell electrical leaking effect and the stack stage structural resistance. Meanwhile, an instrumented single-cell test jig with multiple thermocouples was built, and a series of experimental tests were performed at various conditions. The numerical results based on the single-cell jigs are in very good agreement with the physical test results.

Jan 1, 2005

By S. Koski

The Cerro Verde copper-molybdenum porphyry mine, majority owned and operated by Freeport- McMoRan Copper & Gold, is located 30 km southwest of Arequipa Peru. The concentrator, which produces copper and molybdenum concentrates, started operating in late 2006 with a 108,000 tpd design capacity, processing primary sulfide ore (mainly chalcopyrite and molybdenite). Plant capacity was recently increased to 120,000 tpd. The comminution circuit consists of one 60? x 113" primary crusher, four MP-1000 secondary crushers in closed circuit with dry screens, four 2.4m x 1.6m High Pressure Grinding Rolls (HPGRs) in closed circuit with wet screens, and four 7.3m x 11m gearless ball mills in closed circuit with cyclones. The HPGR circuit is fed by the Secondary Crushing circuit product at a T80 of 35 millimeters, and the HPGR circuit product feeds the Ball Mill circuit at a T80 of 3000 microns. This paper describes operating experiences with HPGRs during these first four years highlighting improvements in operating practices and presentation of data regarding operational efficiencies, also discussed are the primary benefits provided by HPGRs such as production of micro fractured particles, reduced ore Bond Work Index, and reduced power consumption. Cerro Verde represents the first installation of HPGRs in both the copper industry and large scale hard rock mining.

Jan 1, 2012

By D. C. Crothers

"What is new in air compressors? A good deal - the designers have been keeping pace with technical developments in related fields and also contributing new techniques of their own. Plant reliability no longer requires bulky slow-speed machines. Even the reciprocating machines, which still provide the most efficient method of compressing air, have been greatly reduced in size and installation cost for a given capacity rating. New materials and fabrication techniques are being used, by most manufacturers, to produce less costly plants in total. Many packaged plants are available, which generally means a more complete assembly for shipment. This type of construction offers savings in handling and erection costs at the site. A warning is in order, however - the extent of packaging in any given plant should be investigated carefully to determine what is included and just what field costs can be realized. A suggested specification has been offered for consideration when studying comparative costs. Rotating machines intrigue many because of their potential as regard fewer wearing parts, higher speeds and hence smaller units, utilizing less expensive drivers, and lack of contamination of the compressed air by lubricants. The inherent shortcomings of these machines - lower •efficiency and capacity control - have been much improved lately, and this type of plant is now becoming quite popular. Noise control, of much concern to everyone, is another development that has received considerable attention.Systems for efficient capacity control and continuous monitoring of compressor operation offer additional reliability and low-cost operation of the modern compressed air plant. Accessory equipment and its effect on over-all plant operation is also considered."

Jan 1, 1972

By S. E. Wolfe

AKNOWLEDGE of the density of a pulp or suspension is frequently required by the millman, to whom fluctuations in density, which occur in all mill circuits, are of importance and interest. There ,are many w.ays currently in use to determine density and probably the most common method is to take samples of the pulp. The proper sampling of the material is no easy matter, particularly when the pulp contains a sand fraction which settles rapidly. For example, when filling a liter container from the overflow of a classifier, it is al-most impossible to fill the can completely and yet prevent overflow. If there is an overflow, the pulp remaining in the can invariably has an excess of sand and the indicated density will be too high. To surmount such difficulties, and to obtain a continuous indication of the density of a pulp at any desired depth, the simple indicator shown diagrammatically in Figure l was designed by the writer in 1951. Its component parts, numbered as in Figure 1, are as follows.

Jan 1, 1958

By M. Cossette, P. C. A?tcin

At present there is considerable confusion in the asbestos industry with regard to density and porosity measurements of asbestos. In order to clarify the situation, various notions of porosity and density are defined by means of simple schemes and clear symbols are proposed to denote them. An experimental procedure is then preposed and outlined, which is based upon Archimedes' principle. Experimental conditions at each stage of the method are explained clearly in order to minimize the opportunity for errors. Finally, the results of a study on the porosity and density of asbestos minerals having various characteristics are presented.

Jan 1, 1972

By L. Voisin, K. Yamaguchi, D. G. Mendoza, K. Ltagaki

The behavior of arsenic and antimony in the Cu-0 system was thermodynamically investigated to understand their elimination during a blister-making stage in copper smelting. Firstly, the phase relations in a miscibility gap composed of the liquid slag and copper phases in the Cu-0-As and Cu-0-Sb systems at 1523 K were established by a quenching technique. It was found that arsenic and antimony distributed preferentially into the slag phase in the miscibility gap. Secondly, the activities of arsenic and antimony in the miscibility gap of these systems were determined at 1523 K by using a double Knudsen cell - mass spectrometer method. It was clarified that the activity of arsenic in the copper and slag phases showed the negative deviation from ideality while that of antimony in the copper phase a slightly positive deviation. These data obtained in this study suggest a possibility to eliminate arsenic and antimony by means of over-blowing in a converter after discharging the slag.

Jan 1, 2007

By D. V. Ziehlke, J. M. Franklin, T. M. Gordon, A. G. Galley

The Snow Lake-Wekusko Lake region of northern Manitoba conta ins numerous lode gold occurrences, including the largest gold deposit in the Churchill Prov ince, the Nor Acme mine. The Aphebian volcanic and sedimentary rocks of this region are comprised of submarine volcanic strata, overlain by turbidites, both of the Amisk Group, and fluvi atile sedimenta ry strata and bimodally composed subaerial volcanic rocks of the overlying Missi Group. Gold occurs as: 1) accessory gold in volcanogenic massive sulphide deposits, 2) lode gold in shear zones related to sy n- to post-FI thrust fa ults, and 3) lode-gold associated with post-F2 fault . An alteration a emblage of biotite, al bite and calc ite is associated with both groups of lode-gold deposits, and has been superimposed on the regionall y-developed metamorphic assemblages. AJthough these deposi ts are spatial ly related to britt le-ductile faul ts of different initial ages, they appear to have all fo rmed after the major period of reg ional fo lding and metamorphism, and thus may be penecontemporaneous. The alteration is different from the sericite-ankerite-quartz assemblage that is typically associated with gold deposits in Superio r Prov ince. Deposits in thi s area of Churchill Prov ince may have formed either at a higher temperature or a deeper structu ra l level than tho e in Superior Prov ince.

Jan 1, 1986

By Solar D. Andrés

Several large open pit mines are facing the challenge to design and plan an underground transition to sustain the long term future of their operations. The desired underground method is Block Cave since its natural high productivity and low operating cost that could compete against the open pit cost to mine the final open pit pushbacks. It has been found at several operations where this transition is taking place that the pit limit at which transition is performed is rather deep. This aims to think that perhaps several transition projects have started late in the life of an operation producing an over stress in the transition project and reducing the flexibility in the design of the overall infrastructure and a substantial lost in the complete project NPV. Traditionally the approach to plan open pit underground transition consists of sequentially deciding the final pit using a Lerchs and Grossman type of optimization to find the overall maximum pit shell and then running block cave simulations to find the best footprint for the underground option. The research summarized in this paper is related to the development of an integer linear programming model that aims to compute simultaneously the maximum NPV of the combined option final limit open pit and block cave underground footprint. The model has been tested using two large block models representing two of the current operations in the process of transiting from open pit to underground operations. Finally, the integrated open pit underground transition model is going to be compared to the traditional sequential approach in order to define which method achieves the best NPV. The paper illustrates both case studies in depth.

Oct 1, 2009

By G. R. Parslow

U, Fe, Mn, Ni, Cu, Zn and Co data for the sediment in both Key and Seahorse lakes, which overlie portions of known economic uranium deposits in the region, are presented. With the exception of U, Fe and Mn, the elemental distributions can be considered anomalous, in a statistical sense, in both lakes. The U values are of particular interest in that Key Lake is not anomalous, whereas Seahorse Lake is markedly anomalous. Tentative correlations made with background data from other surveys in an attempt to differentiate between anomalous and background values indicate that deviations from linearity in a distribution, and not absolute mean or maximum values, are indicative of anomalous samples within the distribution.

Jan 1, 1979

By A. Aaltonen, S. Paloranta, H. Myllykangas

A property based dynamic model of flotation was built and validated for training purposes. The model is based on the work of the AMIRA P9 project. The recovery of each particle with composition and size is calculated in a given simulation step. The model takes into account machine and operational parameters such as air flowrate and froth height. The model was created using fullscale test data on Pyhlisalmi Cu-Zn-pyrite ore with flotation kinetics of multiphase particles determined. Simulation and validation shows that model can predict the dynamic behavior of the process accurately enough for training purposes.

Jan 1, 2009

By M. Aushouri, S. H. Mansouri, N. Aminizadeh

A thermo-chemical model of the Peirce-Smith copper converter has been developed to predict the molten temperature. The primary assumption of the model was that all matte, slag and gaseous phases in the converter were in thermal and chemical equilibrium. In this model, the matte components were considered only as copper, iron and sulfur elements. In the slag making stage, all the reacted iron was converted to fayalite. The reaction rate of iron and oxygen in this stage was considered to be constant. The converter temperature was calculated by heat balance over time. The model was validated by a detailed comparison with measured industrial data. A good agreement was obtained. The converter temperature depends on process parameters such as oxygen efficiency and molten emissivity.

Jan 1, 2007

By B. N. Church, J. J. Barakso, A. F. Bowman

"An evaluation of mineralization in the Goosly- Owen Lake area of central British Columbia is the result of a comprehensive geochemical study of rock samples obtained from a regional geological survey. The dispersion of metals in country rocks about a line of Tertiary intrusions suggests that these igneous bodies may be genetically related to known sulphide replacements, disseminations and vein deposits. The geochemical investigation is based on the determination of 12 elements from samples gathered from more than 800 scattered field stations. To assist processing and interpretation, the data are subjected to a variety of statistical procedures, including correlation of the elements, factor analysis, clustm• analysis and computer contouring of the elements. Some practical applications of rock geochemistry in regional exploration are indicated."

Jan 1, 1976