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By A. Ghasemi

An alumina-silica coating was deposited on a nickel substrate by sol-gel process, and the structures and composition were evaluated, The sols were made from aluminium and silicon alkoxide, and an acid catalyst including HCl, To produce adherent silica coatings on nickel, various additives such as surfactant, viscose additive and drying control chemical additives were introduced to the system, and appropriate drying and firing cycles were applied after dipping in solution. The hot corrosion and oxidation resistance of the coating at different temperatures were investigated, The structure and uniformity of the coatings were examined by scanning electron microscopy (SEM), The results indicate that a uniform coating of alumina silica can be produced on a nickel substrate by optimizing the composition and process variables of the sol. Coatings can protect substrates from oxidation and hot corrosion at different temperature up to 1000°C, but is not very effective for hot-corrosion resistance at 1000°C.

Jan 1, 2005

By B. Wasmund, M. Parravani, M. Jastrzebski, Z. Coull

"One of the main drivers of overall profitability of pyrometallurgical vessels is refractory lining campaign life. Increased economic pressure to improve vessel life requires innovative solutions to the problem of refractory cooling. Hatch has recently developed a high-intensity, waterless cooling system that bridges the performance gap between external shell cooling and internal water-cooled copper elements. External shell cooling has a limited effectiveness in protecting the refractory lining, because it is thermally insulated from the hotface of the lining by its thickness. This situation does not improve until the lining itself has become worn near the end of the campaign. The patented technology developed by Hatch overcomes this problem by positioning high-velocity air-cooling channels within the lining, closer to the hotface where the cooling benefits can be realized throughout the entire duration of the campaign. The current paper presents the development and application of Internal Air Cooling technology as well as results from the pilot campaign in an operating commercial vessel. Various adaptations for this novel, cost-effective and inherently safe system are also discussed."

Jan 1, 2015

By I. Spector, A. J. Smith

In 1967, BACM Industries Limited started producing walboard at Saskatchewan's first gypsum products plant, located in Saskatoon, using, as a basic raw material, gyp-sum rock supplied from the company's mine near Amaranth, Manitoba. This paper describes the geology of the Amaranth gypsum deposit, the method of mining the rock and the manufacturing facilities used to produce wall-board.

Jan 1, 1970

By Y. P. Wu

Steeply dipping seam refers to the coal seam with dipping angle in the range of 35?55°, which is well recognized to be very hard to mine by the mining industry all the world. In the last two decades, some fundamental researches were focused on the strata behavior of long-wall panel, complicated rock mass breaking process of the steeply dipping seam, overburden stress field developing and evolution, rock strata breaking and moving process, rock structure stability mechanism and control. Results show that it?s presenting macro stress arch-shell (MSAS) of the stress distribution of the overlying rock in steeply dipping seam. The MSAS is the spatial distribution of intensity envelope line under the strength criterion and has the geometry shape asymmetry as well as the stress distribution heterogeneity. The arch- shell base will forward as the working face mine forward and the shell roof will extend to higher overlying strata above the gob. In this paper, the stress arch-shell analysis model and coordinate system were established and analyzed the inclined masonry structure at different zone. Analysis results show that the rock damage at the key part of the arch-shell is the main factor which causes whole overlying rock structure failure. The rock structure instability modes have tension instability of the shell roof, compression-shear instability of the shell shoulder and composite instability of the shell base, meantime, instability coefficient is proposed to determine instability condition. The above research results enrich the complex coal seams mining theory and provide a theoretical basis for mining safely and efficiently in steeply dipping seam.

Aug 1, 2013

By David Morrison

Our present longwall problems in Cape Breton can be grouped under five main classifications. These are: (1) Roof control on the face and on the main roadways leading thereto. (2) Transportation of coal along face and levels. (3) Mechanical loading at the face. (4) Safe method of conducting and applying power at the working faces. (5) Dust nuisance. The usual layout for longwall operation in Cape Breton is to have three, and sometimes four, faces in line with each other, the length of face being from 400 feet to 500 feet (see Figure 1), and producing between 425 and 500 tons per face. Each wall is serviced by a well constructed roadway for transportation of coal, men, and materials, and is operated as an independent unit. Each wall works under a regular cycle of operations: first, cutting and boring; second, drawing hardwood chocks, building midwalls, and shifting panlines; and third, loading. The present method of roof control and operation of longwall faces has developed through trial and error since the commencement of longwall miring in Cape Breton. The basic method of roof control in all longwalls in Cape Breton is: rigid support of the roof in the immediate vicinity of the working faces by hardwood blocks, as shown in Figure 2, accompanied by a cushion support furnished by continuous midwalls, 12 feet wide, constructed of stone obtained from the waste and spaced at 50-foot centres. These midwalls are kept forward to within 4 feet to 10 feet of the working face and allow a gradual subsidence of overhead strata, thus preventing any sudden break at the working face.

Jan 1, 1947

By D. Nie, M. Ren, T. Mo

This paper studied the phenomenon of room temperature creep deformation at crack tip and its effect on fatigue crack growth rate of a X-70 pipeline steel using compact-tension (CT) specimen on a MTS 810 testing machine. Time-dependent deformation at the crack tip under constant load was observed in this steel at room temperature and the amount of deformation produced was seen to depend on loading rate and the magnitude of stress intensity factor. It is found that there exists a critical stress intensity factor below which the deformation decreases with time when the applied load remains constant. It is also found that the occurrence of room temperature creep obviously affects the subsequent fatigue crack growth rate. The observed behavior was explained based on dislocation theory.

Jan 1, 2005

By D. F. Sangster, P. J. Hood, G. A. Gross

"Some results are presented of an integrated geological and geophysical study of Precambrian magnetite-quartz iron-formation in the Kapiko Iron Range north of Nakina, Ontario. Detailed geological and topographical mapping was carried out in conjunction with detailed geophysical investigations such as vertical magnetic field, vertical magnetic gradient, hammer seismic, horizontal-loop electromagnetic and magnetic susceptibility surveys. In addition, oriented drill cores were obtained for magnetic polarization studies.Vertical-force magnetic anomalies within individual rock units showed a strong positive correlation with topographic relief. Moreover, magnetic intensity was found not to be quantitatively proportional to the magnetite content in the rocks, due to the presence of high remanent magnetization of the magnetite. Also, the remanent polarization direction was sub parallel to the plunge of the fold structure and mineral lineation in associated rocks.Vertical magnetic gradient measurements were found to be more accurate in locating buried contacts between magnetite-quartz iron-formation and country rock than the vertical magnetic force data.An in-situ magnetic susceptibility meter was used to measure the magnetite content of iron-formation, and the measurements were subsequently compared with vertical-force magnetic results.The results of the EM survey were inconclusive; some magnetite-rich zones produced anomalies in the out-of-phase component. whereas others did not. The reasons for such inconsistencies are not yet apparent.Longitudinal seismic wave velocities measured parallel to the bedding in magnetite-quartz iron-formation ranged from 10,600 ft/sec. to 14,500 ft/sec. The seismic velocity appears to increase with an increase in deformation of the rocks."

Jan 1, 1966

By A. Singh

"Flotation of fine (< 10 µm) minerals is a challenge exacerbated by the emerging practice of fine grinding flotation feed to better liberate targeted minerals; however, the ability of conventional flotation cells to float liberated fines remains questionable. The Gold Ore solution using Mach reactors was tested at Mintek, South Africa, and showed an ~180% increase in the Kelsall kfast factor, a projected recovery improvement of 4% for the Mach-reactor case, and final concentrate grade twice that of conventional flotation. Theory, pilot plant results, and key aspects of plant design, supplemented by operational plant observations after commissioning, are discussed.RÉSUMÉ Le procédé de flottation de minerais fins (< 10 µm) pose de grandes difficultés, lesquelles sont aggravées par la pratique émergente de l’alimentation du circuit de flottation avec des mailles de broyage très fines pour mieux libérer les minéraux ciblés ; la capacité des cellules de flottation classiques à flotter les fines de minerais libérées reste cependant discutable. La solution proposée par la société Gold Ore, qui utilise des réacteurs Mach, a été testée à Mintek, en Afrique du Sud ; elle affichait une augmentation d’environ 180 % du facteur kfast développé par M. Kelsall dans son modèle de flottation, une amélioration prévue de la récupération de 4 % dans le cas du réacteur Mach, et une teneur finale des concentrés deux fois plus importante que celle obtenue avec la flottation classique. Sont débattus dans cet article la théorie, les résultats générés par l’usine pilote ainsi que les principaux aspects de la conception de l’usine complétés par des observations relatives à l’usine en activité après sa mise en service."

Jan 1, 2018

By S. M. Fatemi-Varzaneh

The AZ31 magnesium alloy is considered as a promising alloy in various applications and industries. Furthermore, to design a proper hot working process (rolling, forging and extrusion), the assessment of hot working behaviour of the alloy is necessitated. Accordingly, the hot deformation behaviour of AZ31 alloy was studied through hot compression testing method. The latter was carried out in a wide range of temperature (523 K to 783 K) and strain rates. The obtained true stress-true strain curves and final microstructures were examined and a partial melting was realized at 740 K. It was concluded that the presence of liquid did change the deformation mechanisms thereby affecting the flow behaviour.

Jan 1, 2005

By The Staff

"A general description of the equipment, personnel and work sequence •being used in the sinking of a circular, concrete lined, 14 foot diameter shaft which at present is at a depth of 2,484 feet. Equipping, lining and sinking of the shaft is being carried out concurrently and waste is re-moved using a mechanical mucker.INTRODUCTIONTHE BUCHANS UNIT of the American Smelting and Refining Company operates a group of mines at Buchans, Newfoundland. Buchans is in the centre of the Province (Lat. 48°47'N.; Long. 56°50'W.), five miles north of Red Indian lake at an elevation of 900 feet and is accessible by 37 miles <Jf private railway which connects with the Canadian National railway at Millertown Junction, and by 47 miles of gravel highway, which connects with the Trans-'Canada Highway at Badger."

Jan 1, 1959

By G. G. Campbell

"HistoricalBARYTES was mined in Nova Scotia as early as 1874 from a deposit at Five Islands, on the north shore of Minas Basin. The first record of the presence of the mineral at the Walton site appears in a report by Selwyn in l893, who states: ""Barytes in considerable quantity occurs in veins in lime-stones at Walton and Pembroke"". The exact site of the present workings was marked •on a map published by Fletcher in 1905.The economic •possibilities of this deposit, however, were not recognized until 1940, at which time we were at war with Germany, who up to that time had supplied 50 per cent of the world's requirements.At that time the Nova Scotia Department of Mines, recognizing the need for certain strategic minerals, induced Canadian Industrial Minerals, Limited, to send prospectors into 'the area to look for manganese. No manganese deposits were found, but a deposit of barytes was directed to their attention, and exploration and development work on the occurrence was proceeded with.IntroductionThe south shore of Minas Basin between the Avon river at Windsor and the Stewiacke river at Maitland has long been known as a potential source of mineral wealth. It had attracted the attention of mineralogists and in the past had produced considerable tonnages of manganese ore and gypsum. Depletion of ore in surface and near surface deposits resulted in a dwindling production, until today only deposits of gypsum are worked."

Jan 1, 1952

By Richard W. Herzer

Introduction Thermal methods have been predominant in the metallurgy of the base-metals ever since the foundation of the industry thousands of years ago. Development in hydrometallurgy has been confined largely to the past six or seven decades. It was at first necessarily slow, then for a number of years rapid progress was made. At present, the uncertain state of the metal industry has curtailed research on the subject; however, in the next few years one may assuredly look forward to an ever increasing use of wet processes. Leaching methods have attained the dominant position in the case of certain metals, notably zinc. For others, they have made no headway at all. Copper presents a situation all its own. Due to the varied nature of its ores and to the large number of localities in which it is mined, a great number of processes have been developed, each suitable in its own particular field. In the case of this metal, therefore, it is more difficult to arrive at definite conclusions. It is the purpose of this paper, first, to review the outstanding developments of base-metal hydrometallurgy, and, secondly, to consider possible Canadian applications of some of the processes in use. The discussion will be confined to the three metals, zinc, lead, and copper, with particular reference to the last mentioned. Zinc General Note At present, zinc is produced by two principal processes, the older retort process and the electrolytic process. The latter is a development of the last twenty years and, judging by its present progress, bids fair eventually to supplant older methods in a large proportion of cases. It is certain, at least, that in the erection of a new plant, a hydrometallurgical process would be given the most serious consideration

Jan 1, 1934

By Wei Huang, Anh V. Nguyen

"Potash flotation is an industrially proven success of flotation of soluble salts, but its collector adsorption mechanism remains elusive. In this paper, specific ion effects in NaCl-KCl flotation with carboxylate collectors were investigated. Flotation recovery and contact angle were determined as a function of brine composition of NaCl and KCl. The experimental results have shown that wettability of KCl and flotation of the soluble salts with laurate collectors were dependent on brine ion composition. Specifically, adding Na+ to brines decreased hydrophobicity of KCl crystals and their flotation recovery. Both KCl and NaCl could be floated with laurate collectors. However, flotation of NaCl was greatly enhanced by adding K+ to brine whereas flotation of KCl was significantly suppressed by the presence of Na ions. The decrease in KCl recovery upon adding Na+ is attributed to the counter-ion binding in the pulp. The flotation recovery enhancement of NaCl in the presence of K+ is explained by two effects: 1) increasing K+ concentration leads to a better dispersion of collector colloids in the pulp and 2) K+ enhances the collector adsorption at NaCl crystal surfaces. The water affinity matching rule can explain the specific ion binding behaviors and supported by the SFG spectroscopic results.INTRODUCTIONPotassium is an important fertilizer. Its primary source comes from potash ores, which are a mixture of sylvite (KCl), halite (NaCl) and many other complex double salts such as carnallite (KCl·MgCl·6H2O), alkali nitrates such as KNO3 and NaNO3, and sulfates-langbeinite (2MgSO4·K2SO4) with water-insoluble minerals such as clay and carbonate minerals. Previously, these salts were recovered with a lengthy hot leaching method, with further crystallization of potassium salts from saturated saline solutions. Selective flotation has been preferred since 1940s. Various collector adsorption mechanisms have been proposed soon after the industrial introduction of potash flotation. These include the formation of the insoluble compound model (Halbich, 1933; Singewald, 1961), an ion exchange model (Fuerstenau and Fuerstenau, 1956), a heat of solution model (Rogers, 1957), the surface hydration model (Schubert, 1988), the surface charge model (Roman, 1966; Miller et al., 1992), the interfacial water structure model (Hancer and Miller, 2000) and the colloid adsorption model (Leja, 1983; Burdukova and Laskowski, 2009). Most of the early exercises attempting to propose a unified rule on collector adsorption mechanisms can be seen as heroic endeavors due to the consideration of a vast number of salts in the pulp including alkali halides, nitrates, and sulfates, even the practically insoluble heavy earth metals. Additionally, several types of surfactants with different polarization features and alkyl chain length have been employed. As for the recent models, due probably to the preferential application of long chain amines as collectors in industrial potash flotation, most researchers are only devoted to collectors with low polarization features like amines and sulfonates (Hancer and Miller, 2000; Du et al., 2014). Collector adsorption mechanisms are therefore proposed based largely on a neglect of carboxylates as collectors. However, carboxylates remain an important collector type in soluble salt flotation systems where both salt minerals can be floated using anionic collectors and cationic collectors. Fatty acid type collectors are still one of the widely used collectors for soluble salt flotation and also one of the first to be applied on an industrial scale for the separation of potash ore (Hernáinz et al., 2003; Titkov, 2004). Here we examine some recent models that are relevant to our study to reveal a long neglected specific ion binding effects in potash flotation."

Jan 1, 2016

By K. Nikkhah, N. Dhadli, G. Freeman

Ammoniacal pressure leaching operations have been in commercial use at the Fort Saskatchewan refinery of Sherritt International Corporation since 1954. Recent improvements have significantly increased the capacity of this circuit. The computer modeling of this process has proved to be a valuable tool in facilitating the evaluation of different operating scenarios in an effective manner. Reagent response in the ammonia leach of nickel and cobalt sulphides is examined using the dynamic process simulation capabilities of IDEAS(TM) software. The dynamic simulation enables accurate measurement of the sensitivity of the process to variables such as temperature, feed rate and ammonia concentration as well as compartmental analysis of metals concentration, pulp density, vent gas composition, and the formation of specific complexes. The complexity of the ammonia leach process makes it a logical choice for evaluation by computational analysis. The methodology for dynamic modeling of a pressure leach process is presented.

Jan 1, 2005

By D. Kalumba, S. Jjuuko

"Thin Spray-on Liners resist relative small deformations (< 1 mm) between rock blocks or fragments in terms of a combination of shear, adhesive and tensile-bond strengths. Shear-bond strength addresses the ability of a thin liner to resist stresses that act parallel to the rock-liner interface. Therefore quantification of shear-bond strength is essential in the formulation of design standards and requirements for Thin Spray-on Liners. In this paper Thin Spray-on Liner support mechanisms are reviewed. In addition previous methods of Thin Spray-on Liner shear-bond testing are discussed. The paper also explains the research being carried out at the University of Cape Town to investigate the effect of different parameters on the shear-bond strength.INTRODUCTIONRock surface support is widely used to combat rockfalls and resulting injuries and fatalities in the vicinity of active faces (Potvin, 2002), where workers spend most of their time (Adams & Baker, 2002; Potvin, 2002; Lacerda, 2004). The conventional (traditional) surface support systems in underground rock support include passive methods such as mesh and lacing and active methods such as shotcrete. However, rockfall sources between 1990 and 2000 in Nevada gold mines showed a steady increase in rockfall injury associated with mesh support as shown in Figure 1 (Lacerda, 2004). The conventional methods also negatively impact the mining operations with regards to costs, logistics and mining cycle times due to large material volumes (Tannant, 2001; Ozturk & Tannant, 2010; Ferreira, 2012). Therefore, these systems need to be substituted, with enhanced methods, in order to realize the business target of the mining industry of providing the planned return on investment made without harm and within budget."

Jan 1, 2015

By H. Nejati

Experimentally, the Semi-Circular Bending Moment (SCB) fracture toughness test results of Basalt Specimens Under Illumination (BSUI) have shown reduction in fracture toughness and failure force as a result of micro-cracking. The fractographic investigation of BSUI confirms initiation and extension of micro-cracks. Determination of a relation between strength reduction (herein fracture toughness reduction) and density, location and orientation of thermo-mechanical induced cracks due to microwave radiation is critically important. Numerical modeling can bridge strength reduction and the density of thermal microcracks generated due to microwave radiation. Discrete Element Modeling (DEM) is a power tool for simulation of micro-crack initiation, coalescence into macroscopic fractures and failure mechanisms in brittle rock specimens under different stress regimes (herein combination of pure tensile stress due to SCB testing, and thermal stress due to microwave radiation). For this purpose, a DEM modeling of SCB testing of basalt using EDEM (i.e., a DEM based software). DEM models are calibrated according to results of experimental SCB testing as reported in previous papers. This paper first reviews some background data on SCB fracture toughness, and experimental results of fracture toughness of microwave treated SCBs. Then it proposes a new methodology for simulation and validation of rock samples exposed to microwave illumination with regard to experimental results, and discusses the correlation between fracture toughness of BSUIs and density of micro-cracks, which is attributed to applied microwave power and duration of illumination.

Aug 1, 2013

By T. R. Chari

The safe-level dilution of low-level radioactive wastes in large volumes of selected granular material is proposed as an alternative method of permanent waste disposal to current Canadian practice of concentration and encapsulation. Accepting the fact that a "background level" of radioactivity exists throughout the world, the authors feel that the concept of controlled dilution of radioactive wastes to a level in keeping with "background" is a plausible alternative to current thinking on the subject and is worthy of equal consideration.

Jan 1, 1979

By E. C. Keeley

Some Safety Measures at Ontario Mines The following safety precautions have of late been taken by several of the Ontario mines: installation of water crossovers; washing clown of faces to show-up missed holes; insistence on gloves being worn as a protection to men&apos;s hands; wearing of safety boots and hats by underground men; and wearing of goggles by all men using hammers, starting holes, etc. In the summer of 1924 the Mclntyre mine began experimenting with means of removing powder smoke from headings by installing fans and pipe-lines of various designs, also with different means of introducing water into the air-blast when blowing smoke. By October of that year they had devised a scheme of water connection between the water and the air line, at a distance of about one hundred and fifty feet back from the face, using two valves and a short hose. By this means a limited amount of water could be introduced into the air which blew into the face, resulting in a fine spray of air and water combined. This spray not only helped to eliminate fumes but also introduced fine particles of water into the air, raising it above the dew point, with the result that when these fine particles of water settled they had attached to them fine dust particles, thus eliminating, to a great extent, the injurious dust caused by blasting. The combined air and water is turned on immediately after blasting and allowed to blow continuously for from four to five hours, until the muckers come on shift.

Jan 1, 1931

By T. B. Williams

THE British Columbia Coal Control was established in 1946 as a branch of the Department of Lands. Its functions are the administration of the Goal Act, the making of field and laboratory investigations bearing on the delineation and utilization of British Columbia coal deposits, and the dissemination of information concerning them. The Department of Lands in the Province of British Columbia retains and administers many of the Province&apos;s resources until such time as they are actively developed under the departments of Agriculture, of Forests, of Mines, etcc. The work of the Control is one of stock taking and appraising. We are picking up where the geological surveys leave off. In an effort to assist in the orderly, scientific development -of our excellent and extensive&apos; ?Coat resources, we are bridging the gap between exploration and geological examination on the -one hand and mining on the other. All coal analyses required in the course of the investigations, together with? those requested by prospectors and others, are carried out in the very modern and efficient laboratories of the Coal, Petroleum, and Natural Gas Control. At its inception, the Coal Control began an investigation of coal seams in the Peace River area, specifically those contiguous to the Pine River valley about one hundred miles west of Dawson Creek. The occurrence of coal in the Peace River canyon, east of Hudson&apos;s Hope, bad been known since 1792, but the first record of production is for 1923.

Jan 1, 1951

By Kremena Dedelyanova

The paper presents research of mechanism for the creation of air bubbles in vibratory a column flotation machine. Factors are discussed that influence the increase in the duration of the bubble in the area of contact with the mineral particles. Formulas are derived for the parameter effect of vibrations, applicable to the design of flotation machine. The collision efficiency of the bubbles in a vibratory column flotation machine is determined.

Aug 1, 2013