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DOME MINES, Limited, is a gold producer situated in the Porcupine area of Ontario, 500 miles north of Toronto. During the year 1960, '71 4,600 tons of ore were milled, yielding gold bullion valued at $6,025,370. Prior to conversion to natural gas, an average of 3,200 tons of coal was consumed annually, one third of which was obtained from Canadian sources with the remainder coming from the United States. Due to the distances involved, the freight charges increased the pithead cost by as much as ISO per cent. Steam is generated at a central boiler plant and used for timber treatment, plant heating and process steam. Until August, 1960, steam was supplied during the winter months by two water tube coal-fired boilers, each rated at 200 boiler horsepower at 100 per cent output. Steam requirement was as high as 150 per cent of boiler rating in the colder periods. The summer load was

Jan 1, 1962

By W. Standifird

"Cohesive fracture is a mechanical model widely used for modeling quasi-brittle fracture in rocklike materials. This work discusses use of this model to simulate quasi-brittle fractures generated by injection stimulation during the process of cuttings reinjection in West Africa. Cuttings reinjection is an engineering practice used for disposal of drilling waste. During this process, hydraulic fractures are created at the target formation and milled cuttings are injected with fluid. In practice, this process must remain in compliance with environmental regulations and zero-discharge policies. The purpose of this study is to determine the following factors of injection design for a field in West Africa: (1) pumping pressure capacity required to successfully perform the injection and (2) the injection rate for injection performance and the value of fracture width under injection.A simplified three-dimensional (3D) finite element model (FEM) was built. A poroelastic plastic damage model was used for simulation of the cohesive crack prorogation within the target formation. For simplicity, fracture development in both horizontal and vertical directions was simulated separately. In this way, the computational burden for one calculation was reduced to a reasonably low level, without losing accuracy of the model. Loads of the model include fluid injection and gravity, which balances the initial geostress field. Various values of injection rate were used in these calculations to determine the most reasonable value of injection pressure. The capacity of pressure of a pumping device was determined using this optimized value of injection pressure.Results in values of width and length of fractures created by the injection are presented. Injection pressures at bottom-hole (BHP) corresponding to each value of injection rate are also given. Numerical results for fracture generation and propagation in a horizontal direction were visualized. The pumping pressure capacity required to fulfill the cuttings reinjection work was determined based on the numerical results of optimized injection rates and pressure. The fracture width was determined using the given pumping pressure. The length and height of the fractures was determined using pumping pressure along with the required volume of cuttings waste to be disposed of into the formation.This work presents a case study of 3D finite element modeling of hydraulic fracturing generated by cuttings reinjection. The results of the optimized injection rate and pressure provide a best practice and a useful reference for cuttings reinjection analyses in this region."

Jan 1, 2015

By A. W. Jolliffe

DESPITE the widespread occurrence of scheelite in Canada, domestic production of this strategic mineral is still quite insufficient to meet wartime needs. Two difficulties have invariably arisen in prospecting for or developing scheelite deposits: scheelite is a difficult mineral to identify, and secondly, its distribution is commonly so erratic that the value of a deposit cannot be determined without arduous and expensive methods of sampling and wet assay. Scheelite's property of fluorescing under certain ultra-violet lamps overcomes the first difficulty and is the basis for a quantitative method developed to overcome the second. It is found that, by use of an ultra-violet lamp, the value of many scheelite deposits may be accurately and speedily determined. The method requires neither elaborate apparatus nor exceptional skill on the part of the operator, and is most applicable to those deposits where the bulk of the scheelite occurs in fairly pure aggregates that are at least one-tenth of an inch across. It has been used in grading some two hundred scheelite-bearing veins in the Yellow-knife-Beaulieu region, Northwest Territories, and various occurrences in the Porcupine district, Ontario. The method requires the measurement of the total area of scheelite exposed in any reasonably large measured cross-section of a deposit. From the areal percent of scheelite so obtained, the tungstic oxide (WO,) content of that part of the deposit may be calculated by means of equations of simple derivation.

Jan 1, 1942

By E. Gaucher, M. St-Amant

"Among the electromagnetic surveys performed by SOQUEM in the last three years, a certain number of the more instructive cases have been chosen to illustrate the theory of electromagnetism by field examples of: (a) The depth penetration of the TURAM as compared to the SLINGRAM (Ronka) method. (b) The limitations of the TURAM as compared to the SLINGRAM method when a conductor dips the wrong way, or when it is small in size. (c) The expression of a shallow-dipping conductor in a SLINGRAM survey. (d) The effect on the SLINGRAM survey of deep ditches or reef structures.(e) A comparison between the CRONE and the SLING-RAM method in the Abitibi clay belt, by means of field and model studies, indicating a usually better signal-to-noise ratio for the SLINGRAM method. From the above and from other experiments, different electromagnetic methods are now being used by SOQUEM, depending on field conditions."

Jan 1, 1970

By L. C. Johnston, J. N. Gills

This paper reviews the basic reactions of the blast furnace and the open hearth furnace, and then discusses the quarrying and sizing requirements of the limestone feed for each. Particular emphasis is placed on the lime-stone at Irish Cove, now being mined under an agreement between Scotia Limestone Limited and Dosco Steel Limited. The drilling and blasting operations are described, along with loading and haulage, plant flow, water supply, power supply and transportation facilities.

Jan 1, 1967

By Ted J. Smith, Stephen E. Kesler

"Zonation patterns are welt developed in the mafic metavolcanic rocks that host epigenetic quartz-carbonate-gold vein mineralization at the Hollinger-McIntyre deposit. Carbonate alteration assemblages are strongly zoned about mineralization. Proceeding inward from background greenschist facies rocks to alteration envelopes enclosing individual veins, the following assemblages are observed:Assemblage I-quartz-albite-chlorite-epidote-actinolite-(calcite)Assemblage II-quartz-albite-chlorite-calcite-epidoteAssemblage III-quartz-ankerite-sericite-(chlorite-calcite)Assemblage IV-quartz-albite-ankerite-sericiteLithogeochemical zoning is equally well developed as variations in whole-rock abundances ofAs, Au, Ba, Rb, and Sb. As and Ba form the most useful zonation patterns, outlining individual ore zones as well as broader trends of mineralization.Gas chromatographic analyses of fluid inclusions in the quartz-carbonate veins indicate that the mineralizing fluid was an H20-C02 mixture. Locally, CH4-rich fluid inclusions are associated with graphitic and/or carbonaceous wallrocks. Fluid inclusions in ore-bearing veins have higher CO2 contents than those in non-ore veins. Extensive sampling and analyses of veins from the area surrounding the deposit reveals a well developed zonation of CO2 contents about the main zone of mineralization. Low CO2 levels (1-2 mole%) in veins are peripheral to the deposit and increase to over 12 mole% in mineralized zones.The observed zoning of the carbonate alteration assemblages is a result of the addition of CO2 to the wallrock, which is consistent with the zoning of CO2 in the fluid inclusions.The zoning patterns delineated in this study are useful in exploration both on a deposit scale and on the scale of individual ore zones."

Jan 1, 1985

By I. Ciabatti

Inorganic salts of hexavalent iron (ferrate (VI)) are versatile reagents for water and industrial effluent treatment because of the strong oxidising effect of the ferrate ion (FeO42-) and the well-known coagulation properties of the resulting ferric ion. Among other applications, ferrate can effectively remove arsenic, cyanide and phenols from industrial effluents. Furthermore, ferrate salts can be prepared from ferrous sulphate, a common byproduct of the steel and titanium industries, and possibly from other iron wastes. Notwithstanding their many potential advantages, the industrial-scale application of ferrate salts, such as potassium ferrate (K2FeO4), for effluent treatment has been hindered by the difficulties inherent in their synthesis and stabilisation. Within a project co-funded by the European Commission, the large-scale synthesis of stabilised potassium ferrate was realised through a new synthesis process, and different applications of the resulting ferrate to effluent and wastewater treatment are under investigation. This paper reports the results of the application of stabilised potassium ferrate for the purification of textile effluents. Laboratory and pilot-scale tests were carried out and the performance of the ferrate was compared to that of chemicals currently used in wastewater treatment. According to these experiments, potassium ferrate is a promising reagent for an effective treatment of textile and other industrial effluents.

Jan 1, 2006

By J. Bigu, M. G. Grenier

"Dust size distribution and aerosol size distribution measurements have been carried out in several Canadian underground uranium mines. In addition, dust samples have been analyzed for long-lived radioactive products of the U-238 and Th-232 natural decay chains using ex-spectroscopy and -y-spectroscopy techniques.From the data collected one may summarize: (a) most airborne particulates are of size below I u-m and 50% by mass are found above 1 u-m; (b) dust clouds are bimodal; (c) preferential deposition of radon (thoron) daughters takes place on airborne particulates in the sub -micron range at about 0.1 u-m; (d) deposition of radon (thoron) daughters is proportional to particle surface area; and (e) ex-spectroscopy and -y-spectroscopy of dust samples reveals the presence of U-238, Ra-226 and some of their short-lived and long-lived decay products.IntroductionExtended inhalation of airborne radioisotopes poses a potential health problem to occupational workers. Because of this, monitoring of radiation and dust levels for dose exposure calculation purposes is not only recommended but in most cases mandatory.CANMET (Energy, Mines a nd Resources Canada) has long since been engaged in a comprehensive monitoring program aimed at determining dust concentrations in the respirable size range, aerosol concentration in the sub-micron range, and in the radioactivity associated with these particulates in underground uranium mines. Measurements have been carried-out with gravimetric dust samplers, dust size selectors (including a horizontal elutriator , a fineparticle spectrometer and Nuclepore* filters of different pore sizes) and a condensation nucleus counter(1 – 6). Inactive and active working sites have been monitored according to some typical mining operations. A summary of these data has been given elsewhere(3- 5)."

Jan 1, 1984

By W. M. Armstrong, John A. H Lund

The paper describes an investigation of some of the tensile properties of single crystal vanadium, poly-crystalline vanadium and polycrystal-line tantalum, in the range of: W°C to -196°C. Techniques employed in the preparation and testing of specimens are discussed in detail. Some results of determinations of the temperature dependence of yield stress and ductility are given, and discussed in terms of the Cottrell-Bilby Theory of yielding. At subnormal temperatures, all the body-centred cubic transition metals in the Periodic Table exhibit; a) the "yield phenomenon" in tension, b) a strong temperature and strain rate dependence of yield stress, and c) a large decrease or complete loss of ductility. The yield phenomenon (existence of an upper and lower yield point) has been explained by Cottrell and Bilby ( 1) in terms of the dislocation-locking effect

Jan 1, 1961

By B. Daniels, A. Tieu, W. Yan, B. Ren, M. Vijay

"Plasma or thermal sprayed coatings are becoming more widely used in a wide range of industrial applications. The preference to use thermal sprayed coatings is mainly attributed to its superior wear, and corrosion resistant properties akin to hard chrome but without the harmful health implications of chrome in the coating process. Specifically, High Velocity Oxygen Fuel (HVOF) plasma sprayed Tungsten Carbide & Cobalt (WC/Co) coatings are presently being tested on aircraft landing gear. This coating can be efficiently applied and is highly resistant to corrosion and wear. However, HVOF coating's durability also makes it difficult to be stripped for inspection and overhaul. Current coating removal methods usually involve a multi-step process whereby the coating must undergo diamond wheel grinding, chemical dipping, grit blasting, ultrahigh pressure (UHP) 380 MPa (55 Kpsi) water blasting, and subsequent chemical dipping, depending on the type and thickness of the coating. As explained by Yan, et al [l]"" a unique method has been developed for removing HVOF coatings with the use of only water. The method consists of modulating a stream of water at a pressure of only 69 MPa (10 Kpsi) with ultrasonic waves to generate a forced pulsed waterjet. The resulting cyclic loading of the hard coating due to the impact of the water pulses easily causes it to flake off the substrate. This paper will briefly describe the fundamentals of the forced pulsed waterjet technique with an emphasis on insitu applications of the removal of various plasma and HVOF coatings."

Jan 1, 2006

By T. R. Kostecki, J. Hirschi

"Analytical engineering design is based upon a trial-and-error iterative and deterministic process. Within this process, the engineer obtains some estimated values, plugs them into de facto closed-form equations, and receives output, which is expected to be a single number that serves as the basis for the design. This number is typically a factor of safety, or some other equivalent strength-stress ratio. This provides the engineer with a quick and relatively quantitative design methodology. This can create problems however, because in mining applications, the actual in situ system is highly variable, complex and often chaotic, which can lead to potentially incorrect conclusions that result in unsafe designs. A more appropriate and reliable approach is a probabilistic analysis for engineering design. This process is used widely in civil and other engineering disciplines, but is often overlooked for applications in coal mine design. Additionally, it seems the amount of past studies using this approach, especially in coal mine design, are rather limited. Considering how the probabilistic approach can account for uncertainty in parametric values and how unpredictable a mining design can be, the authors believe that this approach has potential in mining. This paper will focus on a summary of past studies related to probabilistic analysis in coal mine pillar design and provide recommendations for future work that could improve design reliability. INTRODUCTIONFeasibility and fundamental design procedures for excavations often start with an assessment of mine openings, pillar design, and the surrounding structure by using a deterministic approach with closedform solutions (ex. Bienawski, Obert-Duvall). These are reliable methods, but designers know that the inputs in these closed-form solutions are estimates at best and do not incorporate any degree of uncertainty. This is therefore not an optimal design procedure.A more appropriate design should incorporate some uncertainty because of the chaotic and variable nature of geology and mining conditions in general. In an attempt to account for uncertainty, a probabilistic approach can be adopted, which accounts for deviations in variables and provides a more optimum design solution. By applying a probabilistic approach, a designer can look at multiple failure scenarios at the same time instead of using the same deterministic design over and over."

Jan 1, 2015

By B. Dubreuil, J. -M. Lalancette, D. Lemieux

A gold bearing pyrite concentrate was treated at the pilot scale for the extraction of gold. Mineralogical analysis of the concentrates identified gold to be mainly present in the form of a solid solution in pyrite. Gold distribution resulted in a poor extraction yield of 55 % by direct cyanidation. A piloting campaign including an oxidative pre-treatment by roasting in a fluid bed was followed by treatment with halogens for gold extraction and has led to a gold extraction yield of 94%. Sulphur removal during the oxidation was very efficient at >99.5% and gold extraction by the halogens was completed within a 1 hour contact time. The piloting was performed on a 300 kg sample and used a diluted solution of hypohalites as the oxidizing agent for gold extraction. Sulphuric acid was injected in the reactor during the halogens treatment to lower pH to 2. The diluted solution of hypohalites (1-3%) was generated by electrolysis during the piloting campaign in a diaphragm-less electrolysis cell. The extracted gold was recovered via adsorption over silica and the gold depleted brine was treated for impurities removal. This brine was recycled for further gold extraction. With the recycling of water and brine, the regeneration of hypohalites and with a barren solid that is inert and stable, the Nichromet Extraction technology is a green process where the protection of the environment does not preclude profitability.

Jan 1, 2014

By B. G. Cousins, B. O’Rourke, C. Spence

"Some non-flotation chemicals are added to flotation circuits directly and indirectly to control issues such as scaling and dust in other areas of the operations. Since dosage levels are generally not high, a standard laboratory float test may not be able to determine the effect of a specific chemical on the productivity of the flotation circuit. This paper presents a laboratory testing protocol that uses kinetic float studies to test the effect of normal to extreme doses of antiscalant and dust chemistries (5–100 g/t). Results indicate that this protocol helps to predict potential interference by a particular chemistry on the flotation circuit.RÉSUMÉ Certains produits chimiques ne servant pas à la flottation sont ajoutés directement et indirectement aux circuits de flottation afin de contrôler des problèmes tels que l’entartage et la poussière dans d’autres secteurs des opérations. Étant donné que les niveaux de dosage sont généralement faibles, un essai standard de flottation en laboratoire pourrait ne pas être en mesure de déterminer l’effet d’un produit chimique spécifique sur la productivité du circuit de flottation. Le présent article définit une procédure d’essai en laboratoire qui utilise des études cinétiques de flottation pour vérifier l’effet de doses normales à extrêmes de produits chimiques antitartre et anti-poussière (5 à 100 g/t). Les résultats indiquent que ce protocole aide à prédire l’interférence potentielle d’un produit chimique particulier sur le circuit de flottation."

Jan 1, 2016

By J. E. Zajic, E. A. Sullivan, T. R. Jack

"The release of vanadium, iron, nickel and titanium from the cokes produced in the upgrading of Alberta oil sands bitumen has been assessed for simple chemical leaching processes. Flexicoker coke (Exxon Engineering and Research) has been found to be quite amenable to the recovery of vanadium as well as nickel, iron and some titanium by these techniques, whereas fluid coker coke (Syncrude) and delayed coker coke (Great Canadian Oil Sands) are relatively intractable under the mild conditions employed. The factors affecting the extent of vanadium release are discussed in terms of the surface area accessible, the wettability of the material, and the chemical and physical composition of the coke particles in each case.A novel biologically assisted heap leaching procedure for f1exicoker coke is also described, based on the growth of the chemolithotrophic bacteria, Thiobacillus thiooxidans A TCC 8085, on elemental sulphur added to the coke."

Jan 1, 1980

By C. Acuña

The case is presented that the key role of frother is control of bubble size in the pulp zone. Compared to water alone, the addition of frother produces a narrower distribution and finer bubble size. An empirical model is presented for bubble size as a function of frother type using a normalized concentration. The model provides a benchmark for assessing operations. There is no agreed upon mechanism of how frothers act to reduce bubble size. Prevention of coalescence is a common explanation and this action is illustrated. The case against the 'coalescence' model alone is presented and a breakup mechanism is introduced based on pilot cell and single bubble studies. Phenomena associated with bubble shape, velocity and surface flows are used to illustrate the force associated with surface tension gradients. Breakup mechanisms resulting from this force are proposed. The concept can be extended to high salt concentrations which also promote small bubbles.

Jan 1, 2007

By Tyler Roberts

New Afton mine is an 11,000 tonne per day block caving operation, located 8 km west of the city of Kamloops, British Columbia. Due to the nature of block caving and the weak rock mass at New Afton, the mine has faced and overcome many blasting challenges during its ramp-up to commercial production. As New Afton Mine continues to grow the demand for drill and blast precision has continued to grow as well; any misstep incurs delays in achieving full production capacity. The block cave mining method used at New Afton employs single-shot draw-bells, fired with very little void and blind undercutting, allowing little margin for error. New Afton has made continuous improvements to its blasting strategy by reacting quickly to real-time problems and employing sustainable, repeatable solutions to overcome its unique blasting requirements. Examples of these solutions include: increasing blast hole diameter, casing production drill holes, developing pre-loading procedures and developing strategies for remotely blasting under-broken remnants in both draw-bells and undercutting. Increasing the blast hole diameter has alleviated initial problems with hole plugging in the highly jointed rock mass at New Afton. This has reduced drill-cleaning time significantly and enabled New Afton to meet blasting targets. PVC hole casing was trialed when blasting in extremely fractured ground, where drill holes continually plugged. The casing allowed the drill holes to remain open long enough to load and blast. Calculations were carried out in order to achieve the same explosive energy in the cased holes as a typical blast. Results were generally positive, but more testing is required. Production flexibility and scheduling reliability have been maintained at New Afton by developing a pre-loading procedure for the production undercutting. In doing so, New Afton has been able to keep productivity high by having a flexible production schedule that is not reliant on a specific piece of equipment or production drive to remain productive; this flexibility is because the mucking of undercut material can occur at any stage of the drill/blast/muck cycle. New Afton has developed a strategy for blasting remnant under-break in its draw-bells and undercutting by remotely drilling holes near to the under-broken section and then loading the toes of these holes with emulsion, the remainder of the hole is then filled with grout. The holes are grouted in order to prevent damage to permanent pillars between draw-bells (where the majority of the recovery holes need to be located). Several critical areas were recovered using this technique with little to no damage to the remaining permanent pillars. Innovative blasting solutions have allowed New Afton to overcome obstacles in order to become a producing operation. Moving forward, New Afton looks to continue its trend of innovative drilling and blasting techniques when faced with out of the ordinary situations.

Aug 1, 2013

By R. A. Lunceford, K. C. Shaver

Acquired by Teck Corporation in 1990, the White Earth project, located in southwestern Colorado is the largest titanium resource in the U.S. Teck Corporation has conducted geologic, reserve, mineral processing, pre-marketing, and environmental baseline studies directed toward the economic feasibility of producing titanium pigment. The White Earth project is situated in a 31 km2 alkalic-carbonatite complex intruded into Precambrian granite and metamorphic rocks about 570 million years ago. Perovskite occurs in a 8 km by 1.2 km Acquired by Teck Corporation in 1990, the White Earth project, located in southwestern Colorado is the largest titanium resource in the U.S. Teck Corporation has conducted geologic, reserve, mineral processing, pre-marketing, and environmental baseline studies directed toward the economic feasibility of producing titanium pigment. The White Earth project is situated in a 31 km2 alkalic-carbonatite complex intruded into Precambrian granite and metamorphic rocks about 570 million years ago. Perovskite occurs in a 8 km by 1.2 km

Jan 1, 1998

By K. R. Wood, G. W. McDonald

"The tailings disposal system at Les Mines Selbaie includes dewatering of tailings in a high-capacity thickener, followed by point discharge of the thickened solids to form a stable conical pile. Tailings water drains to ponds formed behind engineered dams, prior to either recycling f or process use or discharge to the environment. Design and economic considerations of the system are discussed. Construction, start-up and operating experiences are also presented.Introduction Les Mines Selbaie is located in the Abitibi region of northwestern Quebec, approximately 700 km north of Toronto and 150km south of James Bay. More locally, the Detour gold mine is 60 km to the west while the Noranda smelter is 220 km to the south.The deposit was discovered as a result of a Questor INPUT Mark VI geophysical survey in 1973, followed by diamond drill programs from 1974 to 1976. Three mineralized zones were delineated and underground exploration was carried out on all three. A production decision for the 'B-zone' copper-gold-silver orebody was made in July 1979. The underground operation started in July 1981, with full production of 1500 t/d being achieved in May 1982.During the planning phase, every effort was made to ensure that the operation would be environmentally sound . The design included the provisions of the then newly proposed provincial environmental guidelines. The tailings disposal system formed the most significant part of the environmental program due to the large volumes of solids and water effluent. In addition, the design allowed for future expansion of the system to accommodate mining of the other zones, thus minimizing future costs and disruptions."

Jan 1, 1986

By Gordon Sparks, Lyle Kajner

"An often over-looked component in the assessed value of a mining property is the value derived from the ability of the operator to limit financial losses during adverse economic times (i.e. low market price, high energy prices, etc.) by suspending operations. Overlooking the value of this type of operating flexibility when conducting mine investment analysis may negatively bias the risk profile for the investment by over estimating the investment's downside potential, thereby effectively undervaluing the investment. This paper illustrates the nature of the value of operating flexibility and discusses how it may be explicitly quantified within the context of conducting stochastic mine investment analysis. IntroductionMining properties are evaluated using an array of techniques ranging from simplistic non-discounted payback calculation s to sophisticated, discounted-stochastic simulation. Stochastic simulation analysis is perhaps the most robust mine investment analysis technique as it not only provides an estimate of the expected value of the property, but also quantifies the associated risks (for examples of stochastic mine investment analysis, see: Billingsley and Yaychuk, 1986; Gentry and O'Neil, 1984; Munro, 1977; or Harris, 1970).The quantification of risk is important as it provides the necessary yardstick required to allocate the corporation's resources efficiently. Resources are said to be allocated efficiently when the corporation's expected long-term financial reward is maximized while at the same time minimizing its risk (see Hertz, 1968; or Markowitz, 1952 for in depth discussions on efficiency as it relates to investment policy). The efficient allocation of resources should be the objective of any rational corporation. Therefore, rational corporations should employ stochastic evaluation techniques when screening their investments."

Jan 1, 1992

By G. Banini

Prior to installation of High Pressure Grinding Rolls (HPGR) at PT Freeport Indonesia (PT-FI) a series of laboratory tests were carried out to determine the design parameters and also determine key performance indicators (KPIs) for the industrial unit. The design parameters derived from the lab test work were then scaled up to estimate the industrial capacity of the HPGRs to be installed. These parameters include specific power draw, specific throughput, and specific force, rolls speed, product size distribution and wear rate of the rolls. This paper compares the performance of the scale-up procedure against the installed industrial size HPGR. Overall, the specific throughput of the industrial size HPGR is higher by a minimum of 30% compared to the expected scale-up value. As a result of the high specific throughput, the specific power draw and grind sizes are below the scale-up expectations in the commercial application. The impact of these factors also contribute to a lower than expected wear rate on the industrial rolls. Installed rolls achieved a service life in excess of 18,500 hours relative to the target of 6,850 hours predicted from the laboratory testing.

Jan 1, 2012