Search Documents

By B. Grinbaum, A. Mazuelos, F. Carranza, N. Iglesias, M. Avila, J. L. Lozano, G. Perez, R. Romero, M. \/aliente

Following a failure of a tailings pond darn at a mine in Andalusia, Spain, a huge effluent stream, that contained about 1 g/1 Zn and significant amounts of ferrous, ferric, calcium, copper, aluminium and manganese cations has to be treated, to prevent pollution of a nature reserve. EGMASA, as the regional government environmental agency, suggested to improve the current depuration process by recovery of the Zn from the effluent. A solvent extraction (SX) followed by electrowinning (EW) was proposed and developed to remove zinc.. A pre-treatment stage consisting in bio-oxidation of ferrous iron by using a bacterial process followed by an alkaline precipitation was employed because iron in the effluent is incompatible with both the SX and the EW processes. The SX process was developed successfully at the laboratory scale and verified in a pilot plant on-site, using two Bateman Pulsed Columns for extraction and stripping of zinc. The results were satisfactory obtaining a recovery of 90% of Zn. The process was suitable for industrial application.

Jan 1, 2008

By Z. M. Zavodni, C. D. Broadbent

"Major rock slides in open-pit mines are rare, but they can develop in spite of sophisticated slope engineering design practice. Experience has shown that, except under high seismic load conditions, the serious slope instability condition is almost always accompanied by the gradual development of one or more tension cracks behind the slope crest, allowing for time-displacement monitoring. Continuous surface displacement measurements with attendant prompt analyses are usually adequate for the prediction of slope behaviour.This paper describes efforts that have been made to quantify parameters associated with slide movement, and compares the displacement records of several large-scale open-pit porphyry copper mine slope failures. Two principal failure stages are recognized in the typical slope failure leading to total collapse: (a) REGRESSIVE STAGE, during which the failure will re-stabilize if some disturbance external to the rock and structure is removed; and (b) PROGRESSIVE STAGE. during which the failure will gradually displace at an accelerating rate to the point of total collapse unless active control measures are taken. Over-all displacement records in both failure stages are apparently of simple exponential form. with a definite break occurring at the onset-of-failure point.Certain common empirical relationships are suggested for the large-scale slope failures analyzed in this study. Based on plots of displacement rate vs time prior to collapse, a semi quantitative empirical relationship is presented for failure collapse prediction. The comparison of historical slide displacement records furnishes the operating engineer with practical guidelines to estimate the characteristics of future large-scale slope failures."

Jan 1, 1980

By C. Zangerl, T. Strauhal, S. Perzlmeier, M. Holzmann

"In high mountainous regions, deep-seated rock slides are often observed in foliated metamorphic rocks such as paragneisses, micaschists and phyllites. Given that comprehensive investigations of deepseated rock slides are extraordinary costly and therefore are rare, most studies are related to investigations in the surroundings of infrastructures and human settlements. In the framework of this study there is an excellent opportunity to gain new insights in the fundamental processes and mechanisms of slowly moving deep-seated rock slides from a case study in the surrounding of a large dam reservoir in Austria. New fundamentals for comprehensive slope stability analyses and hazard assessments and sound prognoses focussing on the long-term stability and deformation behaviour of slopes under changing boundary conditions (e.g. impounding of a reservoir) and/or concepts for mitigation measures can be obtained. Within this contribution, geological field surveys, deformation monitoring, geophysical and drilling data were analysed and presented. Based on the compiled and analysed data, some key-properties of the rock slide will be presented, whereby special attention will be given on the geometry and internal structure, the slope kinematics, as well as hydrogeological and geomechanical aspects.INTRODUCTIONIn high mountainous regions, deep-seated rock slides are often encountered in highly foliated metamorphic rocks such as paragneisses, micaschists and phyllites (Agliardi et al. 2012). Critical situations may occur when deep-seated rock slides fail in a rapid manner characterised by very high sliding velocities, and/or when they develop into long run-out rock avalanches. However, many rock slides in foliated crystalline rock masses either do not move at high velocities nor do they accelerate seriously and form extremely rapid slides. Displacement rates in the range of a few millimetres or centimetres per year are common for this type of rock slide (Bonzanigo et al. 2007, Tentschert 1998, Watson et al. 2007). Nevertheless, some case studies show an activity behaviour characterised by acceleration phases reaching velocities of even metres per day. However a slope collapse is not expected and these slopes decelerate to much lower base activities. The trigger for these phases can be manifold and include heavy rainfall and snow melt, initial reservoir impounding and water level fluctuations, changes in the slope’s equilibrium state due to antecedent slow deformation processes, ongoing erosion processes along the toe of the slope, and others (Zangerl et al. 2010)."

Jan 1, 2015

By L. Gutierrez, M. Pawlik

The rheology artificial mixtures of bitumen with fine quartz of varying bitumen content, as well as actual oil sand ores, was investigated under different physicochemical conditions (pH, temperature). All rheological measurements were conducted using a Haake Rotovisco VT550 rotational viscometer, connected to a fixture specifically designed to measure properties of settling suspensions. It was found that at low bitumen contents (1 %, wt.) the pH of the slurries was the most important parameter that controlled the rheology of quartz-bitumen slurries. At higher bitumen contents (10%, wt.), it was a combination of high temperature and high pH that gave the lowest apparent viscosities and yield stresses of the model mixtures. These model observations correlated well with the rheology data obtained for slurries of actual oil sand ores. The overall results were discussed in terms of aggregation-dispersion phenomena between bitumen and mineral particles.

Jan 1, 2009

By D. M. Cruden

"When two discontinuities form a tetrahedral wedge in a rock slope, a factor of safety for the wedge can be simply calculated (if motion is driven only by gravity and resisted only by friction) from plots of the normals to discontinuities on an overlay of a polar, equal-area spherical projection to which the great circles of a similar equatorial projection have been added.IntroductionThe stability of slopes in rock masses is often controlled by the discontinuities that exist in the masses. In particular, the geometry of the discontinuities constrains the ways in which the mass may fail. Displaying the orientation of the discontinuities on a spherical projection has been found to be a useful way of identifying possible failure modes. The most concise display shows the orientation of the normals (or poles) to the discontinuities that compose the fabric of the rock mass. Computer processing of large samples of discontinuity orientations is necessary if the sampling biases identified by Terzaghi (1965) are to be routinely corrected. Fortunately, displays of the poles to discontinuities (or pi diagrams) are relatively easily produced on the line printer of a computer or by a computer plotter (Cruden , 1978; Ramsden and Cruden, 1979). Unfortunately, further analysis of the stability of a rock mass has tended to use traces of typical discontinuities on a spherical projection rather than pi diagrams; examples may be seen in Hoek and Bray's book (1981)."

Jan 1, 1990

By Robert B. Parsons

"The customary onslaught of government budgets this spring offers lots of interesting reading to the mining industry.While the favourable changes tend to get all the fanfare, there are some ""sleepers"" in the host of proposed changes which will be bitter pills for some mining people to swallow.IntroductionOn a scale of one to ten, the Canadian mining industry will probably give this year's federal and provincial budgets a score that is pretty close to five. Although some budgetary proposals are generally perceived to be favourable to the industry, there are other provisions (and lack of provisions) which are considered to be negative.This month, Tax Notes examines in a summary manner the principal features of the 1985 federal and provincial budgets which are of particular interest to this country's mineral industry."

Jan 1, 1985

By J .. Carignan, Y. Dembele, J .. Guha, A. Fowler, A. Gobeil

The Barlow Lake stratigraphic section comprises the top of the Gilman Formation, the Blondeau Formation and the three sills of the Cummings Complex. Representative samples were analysed to allow characterization of the chemo-stratigraphic profile and geochemical affinity of the six rock facies found in the section. All the mineralized horizons are associated with sedimentary units. Geochemical signatures associated with the mineralizations are either very weak or very localized and shown by increases in K20 around the mineralizations and Fe203 near them. The mineralizations are stratiform, synvolcanic but resedimented and remobilized by regional metamorphism and possibly by hydrothermal activity initiated by the intrusion of the Cummings Complex. The evolution of the sedimentary basin with the decrease of its depth is confirmed by the chemo-stratigraphic profiles. Stratigraphic position in the section is important in order that the chemo-stratigraphy may serve as a guide for mining exploration in the distal facies of the Blondeau Formation.

Jan 1, 1984

By G. Ergin

The interactions taking place between Al-Mg alloys and the bed media during aluminum filtration are not yet well understood. These interactions were studied using the infiltration technique. The reaction interface was analyzed using different techniques such as SEM and TEM. Only spinel formation was observed at the interface regardless of the type of alumina and contact time. This paper discusses the results of the study.

Jan 1, 2004

By D. G. Champion

"A comparison of diesel engine power ratings with in-service capability, and the selection of unit size and total number of units are discussed in the paper. Engine specific fuel consumption and its evaluation in relation to manufacturers' tolerances and equipment load factors is reviewed along with the suitable plant layout. The potential for heat recovery is discussed in connection with simple and operable recovery systems f or exhaust and cooling circuits. Maintenance standards as related to improved reliability and reduced fuel and operating costs are also outlined. IntroductionDiesel generators are used in Canadian mining operations to provide electrical power for "" base- load"" requirements in some instances and for ""stand-by"" or ""emergency"" power in almost every producing mine in the country . There are over 300 mines in Canada of which only a handful have to generate their own electricity. Only one or two mine s enjoy access to a hydroelectric site. Consequently, the diesel engine is the principal prime mover because of its high efficiency relative to other prime movers in the size range in question.The author has been associated with several “base-load” plants in addition to participation in numerous projects requiring emergency diesel generators. Records indicate that engine performance in term s of reliability and efficiency lags behind other industries where the diesel engine is used more extensively, such as the shipping industry which is able to make a more prudent selection of original equipment and enjoy easy access to highly skilled operating and maintenance personnel. It is hoped that the contents of this paper will be of value to Canadian operators of diesel generators, in the generation of prime power or applications for back-up power."

Jan 1, 1986

By D. B. Stewart

This paper reports on an investigation undertaken to determine the exhaust gas temperatures of operating underground mining equipment. The effectiveness of platinum catalytic purifiers is discussed. From exhaust temperatures, it is concluded that LHD engines are highly loaded, haulage truck engines are moderately loaded and utility vehicle engines are lightly loaded.

Jan 1, 1979

By L. Mohammadi

Outline ?Background on the accident at the Sullivan Mine No.1 Waste Dump ?Holistic approach to understand the reason for accidents (Atmospheric) ?Specific hazards at reclamation sites ?Regular atmospheric risk assessment at reclamation sites ?Fuzzy risk assessment ?Managing risk at legacy sites

May 1, 2010

By Louis Tellier

SIDBEC commenced detailed planning of major capital expenditures to install integrated steelmaking facilities in 1969. Today, less than IO years later, SIDBEC and its subsidiaries have completed major mining, concentrating, pelletizing, direct reduction ? electric furnace steelmaking and continuous casting plants. The total cost of these projects was almost 1 billion dollars. The philosophy behind the project planning and the evolution of management control are explained. These extensive projects were undertaken during a period of exceptional inflation and a disturbed labour climate, but were nevertheless completed with only modest overruns, with good control of timetables and with exceptionally good start-up performance. Project planning, relations with consulting engineers, introduction of new technology, purchasing and field management and cost control are discussed.

Jan 1, 1979

The Red Lake greenstone belt is an irregular mass of lavas sedimentary rocks and intrusives which is approxiately 35 miles long 18 miles wide and 7 miles deep. Basaltic volcamcs are the oldest rocks w1thm the belt. They are believed to have been laid down on an ancient crust which is at least 3 billion (3 x 109) years old and was composed partly of sediments. The basaltic rocks are overlain by acid volcanics and sedimentary rocks which have been complexly folded and are preserved as a down-folded remnant of younger rocks within the older crust. The volcanics and sedimentary rocks of the greenstone belt have been cut by intrusives with a wide range of composition. The emplacement of the intrusives and the accompanying regional metamorph-ism which terminated the orogenic activity in this area are believed to have occurred approximately 2.4 billion years ago. The basalts and many of the basic and ultrabasic intrusives undoubtedly had their source in the sub-crust or mantle. At least some of the granitic intrusives are believed to have had

Jan 1, 1965

By D. O. Tansey

This paper will describe the mechanisms involved in delay blasting and how they are applied with the use of D.S.B. It will examine the control of potential damage resulting from detonations, and show how good fragmentation and efficient recovery of this material blasted can be achieved

Jan 1, 1979

By G. R. Guillet

"Bricks made from local Paleozoic shales, and floor and wall tiles made from imported clays, both established record production volumes in 1985 and are the strongest segments of Ontario 's clay products industries. However, renewed interest in traditional materials also supports a good market for clay flower pots and flu e liners, and innovative processing studies are showing promise for possible new production of clay roofing tiles. This paper reviews the highlights of a comprehensive study of Ontario's clay products industries, completed in 1986. IntroductionFor some years now, Ontario' s clay products industries have been unspectacular in their attempt to cope with the recent recession and the impact of alternative materials. But a strong demand for bricks in recent years has done much to dispel the gloom.Bricks, drainage tiles, sewer pipes, flue liners, structural and partition tiles, and flower pots have been commonly referred to as ""heavy"" clay products, and they have been based largely on local clays and shales. To this list might be added expanded aggregate and mineral wool. Clay refractories, sanitary ware, electrical porcelain , art pottery, and floor and wall tiles are not considered heavy clay products, and are commonly made from a variety of ceramic materials, many of which are imported.Production facilities for heavy clay products often began in Ontario as small family enterprises, using whatever clay was available locally to supply the local market with building bricks and other clay products needed for construction. Improved road systems increased the market range for these plant s, and new technology and industry standards resulted in gradual"

Jan 1, 1988

By Marc Lavigne

"The Lac Knife graphite deposit was estimated, as part of a feasibility study, using a geostatistical ore reserve estimation method: ordinary kriging. Based on the geology and its interpretation, the results of a variogram study, and the statistical parameters of the grade distribution of the core samples and the composites through the mineralization, the deposit was divided into three separate zones (west, centre and east), and each of these zones was then analyzed and kriged independently.The geological ore reserve estimation results of ordinary kriging are compared to the results of a conventional method (sections) used previously. The two methods gave almost similar reserve figures. The conventional method provided a +2% estimation for tonnage and + 10% for grade because it ignored the spatial relation between sections and samples, and ordinary kriging gave a more accurate longitudinal definition of the deposit.Finally, the paper concludes with the advantages of proceeding with ordinary kriging, namely: higher flexibility (change of cut-off grade), better deposit resolution and enhanced selectivity for the design of the open pit.IntroductionWithin the context of a complete feasibility study for the Société d' Exploration Minière Mazarin Inc., specialists of the Mines and Geology Division of Roche Ltd., Consulting Group, defined a modelling method appropriate to the graphite deposit of the Lac Knife property near Fennont. Many patterns were considered. Based on the geology of this deposit, the planned mining method, the statistical parameters of grade distribution and the variogram study, the process of reserve estimation retained was to use the ordinary kriging in a selective way. It was required because the geometry of the deposit is such that it was unthinkable to apply ordinary kriging without restrictions.This paper gives a detailed explanation of the observations and interrogations which led to the choice of this ore reserve estimation method, and the calculation procedure itself."

Jan 1, 1991

By J. E. Udd, S. Bharti

"ABSTRACTMonitoring of stability conditions in underground mines permits management to assess the response of the rock mass to mining strategies. Monitoring of movements, if sufficiently early, may also permit operators either to avert potential failures or to develop alternative approaches to extraction.The Falconbridge organization has been a leader both in the uses of rock mass stability monitoring techniques and in the development of instrumentation.In this paper, the authors review the Falconbridge approaches to monitoring, and present case history examples to illustrate the application of the various instruments used.RESUMELa surveillance des conditions de stabilité dans les mines souter-raines permet aux chefs d'enterprises d'évaluer les réactions de la masse rocheuse aux méthodes d'extraction minière. Si le contrôle des mouvements du terrain est effectué assez tot, l'exploitant pourra prendre les mesures qui s'imposent, soit pour éviter les détériorations possibles ou pour mettre au point de nouvelles méthodes d'extraction.Le groupe de la Falconbridge a ére le premier a utiliser des techniques de vérification des conditions de stabilité de la masse rocheuse et a mettre au point l'appareillage requis.Ce document présente une revue des méthodes employées par la Falconbridge pour assurer la surveillance active de la stabilité de la masse rocheuse et illustre au moyen de cas concrets la manière d'utiliser les divers appareils."

Jan 1, 1987

By James Stenhouse

Abstract The aqueous oxidation of pyrite in caustic solutions under oxygen pressure was investigated by measuring that effect of reaction variable on oxygen consumption by the reactions. From the results of this investigation, a model for the process has been proposed. In this model, sulphur diffuses as a positive ion through an oxide layer which forms on the sulphide particles and is then oxidized to sulphate ion. Iron is oxidized by substitutional diffusion of oxygen atoms into the oxide layer. The effect of most reaction variables on the rate of oxygen consumption can be explained with this model. Introduction Recent investigations (1,2,3) have shown that certain sulphide ores can be readily leached by agitating the ore in the form of a pulp under pressure in the presence of oxygen. Since very little was known of the mechanism of this oxidation, a programme of investigation was inaugurated in 1949 in the laboratories of the Department of Mining and Metallurgy of the University of British Columbia. Financial support for the investigation was received from the National Research Council in the form of student grants and bursaries, from the Canadian Liquid Air Company, Limited, and from the Consolidated Mining and Smelting Company of Canada, Limited. The first objective was to devise a technique to study the primary oxidation reactions in aqueous solutions and to apply the technique to a detailed study of the oxidation of pyrite in caustic solutions.

Jan 1, 1952

By M. Brochu

In this paper, we present a computer-vision approach developed for wall-thickness measurements of corroded pipes inspected by double-wall radiography. The main objective of the work is to optimize data collection and film interpretation using computerized image analysis. To date, the system is able to identify the inner and outer contours of a pipe and perform wall thickness measurements at each pixel of a radiograph. This will be presented by analysing pipes having different dimensions. Another important feature of the system concerns the algorithms' adaptability to pipe wall texture. In other words, image analysis is automatically refined around rough or corroded areas. This allows more precise thickness measurements and shape identification in critical sections as will be demonstrated with examples. Finally a brief overview of results exploitation will be given and compared with human interpretation. It will show the reliability of automated image analysis and the many possibilities offered by complete output analysis.

Jan 1, 2005

By J. E. Dutrizac

Mercury balances have been obtained for the flotation circuits at Pamour Porcupine Mines, Timmins, Ontario, and at Brunswick Mining and Smelting Corporation, Bathurst, New Brunswick. The mineral form of mercury in both deposits has been ascertained. At Pamour Porcupine, the mercury is approximately evenly divided among sphalerite, native silverelectrum and tetrahedrite-tennantite; at Brunswick Mining, this element is contained mostly in the sphalerite, although tetrahedrite (and possibly pyrite) also contains minor quantities.

Jan 1, 1979