Search Documents

By H. H. Gardner

INTRODUCTION THE problem of mechanization is one of the most vital in the minds of Alberta coal operators today. In these times of constantly increasing operating costs, any way of decreasing the cost of a ton of coal must be explored to the limit. There seems no better field for such effort than the successful application of power to the mining and loading of coal. We are fortunate in having neighbours to the south who have made .remarkable progress in recent times along these lines. Higher tonnages per man have resulted in higher wages to the employee and lower cost to the employer. It might seem that our problems could be solved merely by imitating our neighbours. Unfortunately, neither practice nor experience substantiate this conclusion. It is with the purpose of reviewing our accomplishments, as compared with practice in the United States, and at the request of the Prgoramme Committee for this meeting, that this paper is written. The Committee believes that such a general discussion and comparison may well lead to further advances in our mining methods. SUMMARY OF PRACTICE IN THE UNITED STATES A visit to the highly mechanized coal mines of the United States is always most instructive and encouraging.

Jan 1, 1951

By B. Haneman, J. A. Gorst, W. Slabbert

"The Bayer process involves the digestion of bauxite in caustic liquors at high temperature and pressure. Typically the digestion section of the plant involves the heating of liquors up to the digestion temperature followed by flashing of the digestion product to atmospheric pressure with the flashed steam used to pre-heat the incoming cold slurry. Despite the heat recovery, the digestion process is a high consumer of energy. The application of tube digestion technology in such plants has resulted in significant improvements in refinery energy efficiency with associated benefits of process simplification and refinery flow sheet capital cost reduction. This paper reviews the potential application of this technology to other metals within the non-ferrous industry.THE BAYER PROCESSA typical Bayer flow sheet is shown in Figure 1. The raw feed material bauxite (containing aluminium hydroxide as gibbsite Al(OH)3 and boehmite AlO(OH)) is digested in caustic liquors (caustic soda is the solvent) at high temperature and pressure. This process extracts the alumina and silica and any carbon present on the ore. The slurry is then flashed down to atmospheric condition allowing for heat recovery from the flashed vapour and producing slurry supersaturated in alumina.Following the digestion process the mud is removed via thickening and then pressure filtration to remove fine particulate and produce a clarified liquor with dissolved alumina in solution. The resulting pregnant liquor is then cooled allowing the alumina in solution to precipitate as aluminium trihydrate Al(OH)3. The precipitated hydrate is then filtered and washed and classified into fine and coarse fractions. The fine material is returned to the precipitation process as seed while the coarse fraction is calcined at high temperature to produce alumina. The filtrate from the filtration process (spent liquor) is then heated by the incoming pregnant liquor before being fed to an evaporation process which produced the strong caustic liquor required in the digestion process. Finally, the mud from the thickening process is washed to recover caustic and then fed to tailings ponds. The washer overflow is then mixed with the digester product to increase super-saturation."

Jan 1, 2012

By Tom Gaines, G. S. Brant, J. G. Debanne

"AbstractThe Bonnie Glen oil field, one of Canada's largest, lies about fifty miles southwest of Edmonton, Alberta. One hundred and thirty-eight wells have been completed in this field since its discovery in January, 1952. Five different procedures have been used in completing the producing wells.The reservoir is an Upper Devonian biohermal reef with good porosity and uniformly high permeability. The top of the reef is quite flat but the flanks slope at angles approaching 20 degrees from the horizontal. The reservoir has a gas cap with a maximum thickness of 400 feet, an oil column of 300 feet, and a :porcus aquifer of over 300 feet. The reservoir pressure is now 2,400 pounds per square inch gauge at datum ( -4100 M.S.L.).Because of the high permeability and the high •pressure, lost circulation and resultant blowouts are a particular hazard in drilling at Bonnie :Glen field. To reduce the dangers of blowouts, it is general practice to run casing to the top of the reef. If the reef is encountered 'high' it was usual practice to run a liner and perforate for completion. Wells penetrating the •reef below the gas/oil interface were either completed in open hole or through casing perforated opposite the oil pay, with the former method more frequently used. Eight wells were completed by the Humble-Otis permanent-type completion, and recently five high wells were completed open hole with the gas •cap exposed. This latter completion, 'tubing submergence', has proved highly satisfactory thus far.The open-hole type of completion is cheaper than the liner perforation method and results in better well performance. More experimentation and data are needed before the tubing submergence method can be recommended unqualifiedly. but all evidence thus far favours its use in reef reservoirs."

Jan 1, 1955

By Richard Stewart

There are highly competitive world markets in most of the minerals being mined today. The high standard of living we enjoy in North America results in ever increasing productivity through mechanization and automation. Conventional underground and open-pit mining practices throughout the world are constantly changing to reflect the engineering advances of our technology. New records in tunneling, shaft sinking and excavating are being established. Larger and faster equipment is in production. Mining operations are being studied in detail to improve materials, methods and machines. Standards and controls are being established to measure the performance of people and equipment. These steps all tend to improve our present performance. In addition to these short-range improvements, however, there are the basic research and applied research studies which are aimed at developing entirely new approaches to our mining problems. Basic research in rock mechanics is coupled with applied research in rock penetration, fragmentation and stabilization.

Jan 1, 1963

By Corby G. Anderson, Caelen D. Anderson, Patrick R. Taylor

"The United States contains a variety of domestic rare earth element mineral sources containing such as ancylite, bastnasite, monazite, and xenotime. Research has been performed to investigate the fundamental surface chemistry involved in the froth flotation of these minerals, and apply the knowledge gained to substantiate the results through experimental testwork on a domestically sourced rare earth ore. This paper will outline the fundamentals and literature of rare earth mineral flotation, review its industrial applications and provide some recent research updates.THE RARE EARTH ELEMENTSRare earth elements (REE’s) are a unique family of elements with nearly identical physical and chemical properties. They account for approximately 1/6th of all naturally occurring elements, but the entire group occupies only one position on the periodic table. These 15 elements make up the lanthanide series (atomic numbers 57–71), and all but one (promethium) occur naturally. In addition to these 15 elements, yttrium and scandium are also considered rare earths since they tend to occur in the same deposits as the rare earths and share similar physical and chemical properties as seen in Figure 1. In particular Figure 2 denotes, a cartoon of the subtle differences in each caused by the 4f atomic sub shell (Gschneidner Jr., 1964). These subtle differences result in very difficult challenges in the selective concentration and final separation of each rare earth. (Anderson, 2015, Kronholm, Anderson, Taylor, 2013)Rare earths are separated into two different subsections; the “lights” or LREE’s (lanthanum57 through europium63) and the “heavies” or HREE’s (gadolinium64 through lutetium71). Yttrium is generally considered a heavy rare earth since its ionic radius is close to that of the HREE’s, while scandium is not considered either a light or a heavy."

Jan 1, 2016

By R. K. Collings

Mineral wastes from the mining, metallurgical and chemical processing industries in Canada amount to about 800 million tonnes annually. Such wastes often are largely non-metallic in composition and are of interest for traditional non-metallic mineral uses and applications. Mineral waste disposal and maintenance are costly; furthermore, these wastes may pollute groundwater, rivers and lakes. These factors and an increased appreciation of the potential utility of some mineral wastes have stimulated research in this area.

Jan 1, 1984

By A. Ignatieff

"A practical picture of the effects of stress and of the structural environment in an extraction area in a bedded deposit is described, and the main factors of ground control where principles of rock mechanics can be applied are discussed. Reference is made to early work in Europe, where systematic rock mechanics studies started in coal mines, as well as to the early work in the Canadian coal mines.During the past two decades, considerable theoretical and experimental knowledge, pursued both in the laboratory and in the field, has accumulated throughout the world, but the state of the science still does not permit application of substantiated theory such as is found in the design of above-ground structures, largely because of the complexity of the rocks. The mining engineer, as oppm1ed to the civil engineer, is constantly faced by exposures of new ground that is often subject to unpredictable discontinuities. However, the rationale already developed by rock mechanics principles and experimentation provides concepts and information that may be useful in selecting mining layouts. These concepts and existing measuring techniques can also assist ground control as mining progresses.Many of the bedded deposits, much as coals and evaporites, have pronounced deformation properties, and there are limitations in making stress measurements within short distances of mine openings or extraction areas. On the other hand, the measurement of movement of the hanging wall (roof) and footwall (floor) of roadways and extraction faces, as well as the sides of pillars, provides a most useful tool in assessing ground stability.This paper is to be regarded as a brief progress report with particular reference to Canadian applications of rock mechanics to bedded deposits."

Jan 1, 1968

By C. Turek, R. Henderson

Mine planning is the foundation of value for a mining company. Good mine planning requires solid understanding of the ore body, rigorous standards and processes, robust and useful information technology and skilled people. Life of mine planning is key to identifying strategic direction for any mine and short range mine planning is key to delivering forecast and budget expectations. Mine planning at Kinross has been identified as a critical success factor and initiatives are being prepared to improve the quality of our plans and to build bench strength in our teams. The Kinross Way for Mine Planning (KWMP) has been developed and implemented to establish the standards to ensure a strong business foundation. This paper briefly describes the process used to develop the KWMP and presents a selection of mine planning best practice initiatives at Kinross mines.

Jan 1, 2011

By Pierre Sauvé, Alex Makila

"The Camflo stock of porphyritic quartz syenite is an irregular pipe-like body 200 metres in diameter injected along the axial plane of an E-W trending F2 fold, near the contact between the. Kewagama and Malartic groups. The stock plunges 55° to the NE, almost parallel to the fold axis. The stock, exhibiting pervasive, weak cataclasis with numerous, locally auriferous quartz veinlets, is cut by minor faults striking WNW and dipping about 45°NE.Two types of gold ore are distinguished at Camflo: ""porphyry"" ore and ""fault zone"" ore. ""Porphyry"" ore, accounting for 90% of the gold produced, forms wide zones within the stock. The zones are irregular in shape but tend to be oriented E-W in plan view (on a horizontal plane) and are elongated paraliel to the plunge of the stock. These zones are more abundant in the northern part of the stock. Differences between ore and barren porphyry are not obvious. ""Fault zone"" ore occurs outside the stock along minor faults, particularly in differentiated sills offer rodiorite and felsic granophyre. Gold grade is roughly proportional to the pyrite content which in turns depends in part on the original magnetite content of the host rock. Although both types of ore show some correlation between Au and S, the Au/S ratio is considerably higher in porphyry ore.The bulk of the gold is in quartz syenite and in felsic granophyre, the most brittle lithologies at the mine. Presumably, the vertically continuous, pipe-like stock, made up of shattered rock, provided the main channelway for the ascending mineralizing solutions."

Jan 1, 1990

By M. Fan, H. E. Wyslouzil, J. Kohmeunch

Eriez HydroFloat(TM) separators and Canadian Process Technologies (CPT) flotation columns have been developed to overcome the limitations of traditional flotation cells in recovering coarse and fine particles, respectively. The flotation column can effectively separate 30-5 µm phosphate. Several industrial-scale HydroFloat separators have been installed in phosphate and potash beneficiation plants. Industrial-scale ultra-coarse (+850 µm) phosphate separation results suggest that a more-than 40% BonePhosphate- of-Lime (BPL) recovery increase and a 37% collector consumption reduction can be achieved. The paper describes the applications of Eriez HydroFloat separators to coarse particle separation and the CPT flotation column to fine/ultrafine particle flotation.

Jan 1, 2009

By R. H. Brooks

Blasthole stoping methods were introduced at Birchtree Mine as an alternative to the original cut-and-fill and shrinkage stoping methods. The object was to take advantage of the ore structure and conditions, and achieve increased productivity. This paper outlines the design, operation and economics of three areas which utilized blasthole stoping. The 108areafrom 2300 level to 1500level was converted from cut-and-fill to sublevel blasthole stoping based on a block mining-and-filling sequence. The second area, the crown pillar of 110 mechanized cut-and-fill stope below 500 level, was recovered using horizontal rings drilled from raises within the ore zone. The third area, the 83 orebody from 1300 level to 1100 level, used the vertical crater retreat (VCR) method with large-diameter blastholes. Blasthole stoping has increased productivity and improved operating conditions.

Jan 1, 1979

By D. B. Dreisinger, D. G. Dixon, G. Nazari

"The kinetics of chalcopyrite leaching in acidic ferric/ferrous sulfate media under atmospheric conditions in the presence of pyrite has been investigated. It has been found that pyrite samples from different sources affect the rate of chalcopyrite leaching differently. A strong correlation between the amount of silver associated with the pyrite and its effectiveness has been noted. In this study, improvement of the catalytic properties of pyrite such that all pyrite samples accelerate the rate of copper extraction regardless of their sources is demonstrated, and a detailed discussion of the mechanisms involved in the process of chalcopyrite leaching in the presence of silverenhanced pyrite is presented. INTRODUCTIONIt is well known that chalcopyrite resists leaching in sulfate media. It has been proved that pyrite facilitates the leaching of chalcopyrite (Berry et al., 1978; Dixon et al., 2008; Mehta and Murr, 1983; Muñoz et al., 2008; Nowak et al., 1984, Tshilombo, 2004). Considering the catalytic effects of pyrite on accelerating the kinetics of chalcopyrite leaching, Dixon and Tshilombo (2005) have developed a new process, known as Galvanox™, which has several advantages over other hydrometallurgical processes. Galvanox™ runs under atmospheric conditions, so it requires only low-cost leaching tanks. The sulfur yield at this temperature is high (>95%) which leads to low oxygen consumption and low sulfuric acid generation. The operating temperature is below the melting point of sulfur which eliminates the use of surfactants. This process also does not require fine grinding. Reaction 1 shows the overall leaching reaction in the Galvanox™ process.CuFeS2 + O2 + 2 H2SO4 = CuSO4 + FeSO4 + 2 S0 + 2 H2O (1)Complete copper recovery from the Galvanox™ process can be achieved at a considerably higher rate than other atmospheric ferric sulfate leaching processes (Dixon et al., 2008). Recycling pyrite and recovering copper from tailings with the Galvanox™ process have also been evaluated in continuous pilot leaching campaigns (Dixon et al., 2007)."

Jan 1, 2012

By J. Bouchard, A. Desbiens, M. Maldonado, R. del Villar

ABSTRACT: Despite many years of practical applications in mineral processing plants, the potential of column flotation has still not been fully exploited. The challenge in measuring some key variables is certainly an important contributing factor to this situation. Reliable online measurement of variables, such as the froth depth, bias, gas hold-up, frother concentration, bubble surface area flux, and bubble size distribution, provides opportunities for the application of various advanced control strategies and real-time optimization based on an economic criterion. For several years, Université Laval’sLaboratoire d’observation et d’optimisation des procédés researchers have been working on these opportunities. This paper describes the most recent advances and current research trends.

Jan 1, 2011

By M. Zanini, D. Wong

ABSTRACT: Metals market improvements in 2005 drove the desire to increase nickel throughput and the production of nickel oxide sinter at the Vale Ltd. Copper Cliff smelter. Significant difficulties were encountered due to the unreliable quality of Bessemer matte being produced. Concentrate feed changes and the loss of technical and operational expertise during the previous market downturn contributed to the challenge of making the required improvements. Significant progress has been made in the converter aisle by focusing on employee engagement and standardizing best operating practices for a new generation of skimmers. This paper documents these initiatives and seeks to balance the art and science of converting.

Jan 1, 2012

By A. W. Lovett

"THE last two years have been years of recession or, perhaps, years of marking time, depending upon whether the observer is a pessimist or an optimist. There has been a slackening in the industrial tempo that has been reflected in many ways in the national economy. As one of the chief barometers of economic health, the consumption and supply of energy reflect this slowing up.These same two years have also seen significant changes in the relation between the sources of energy. In periods of declining demand, it has happened in the past that coal, as the basic or residual source of energy, has shown the effects to a greater extent than the other energies. In these two years, however, in addition to this usual effect, there has been the acceleration in the Joss of market to diesels in the railway consumption category and the continuing decline in domestic consumption. The story of these years is presented in the statistical tables that form the foundation of this paper. Statistics, particularly in the form of tables, are rather dry and are sometimes difficult to follow but the overall developments are illustrated by graphs which present a more striking picture."

Jan 1, 1959

By M. Santaluce

"The revamp of critical process assets that require a significant plant outage (shutdown) presents a unique and demanding set of challenges for plant operators. They are executed in a more complex Brownfield environment, typically with limited working space and often involve unknown conditions or scope. For plant operators, such a project is often a high cost event both in terms of opportunity cost of lost production and the resource cost of labor and materials. It can also be a high risk event in terms safety, environment, and future plant reliability/availability. This impacts current and future performance or Overall Equipment Effectiveness (OEE). In our experience, the sequential nature of the EPCM approach does not provide the proper framework to facilitate the level of coordination, stakeholder cooperation and detailed planning required to adequately address the construction and shutdown complexity of a critical asset revamp projects. This paper proposes a more integrated approach to handling shutdown revamps of critical assets. Its main thesis is to involve the key performing stakeholder groups early in the project lifecycle (engineering team, procurement team, construction team and plant operations) to form an integrated shutdown management team that is focused on ensuring delivered results are aligned with project objectives. In this model, the construction team executing the shutdown/construction is preparing the detailed shutdown/construction planning concurrently with detailed engineering and procurement planning. This allows construction/shutdown requirements to influence engineering and procurement, with the desire to optimize safety, speed, quality and cost. The paper also discusses how to overcome the procurement hurdle in applying such an approach. The outcome of this integrated approach is better planning, coordination, communication and alignment between the project stakeholders, a shutdown/construction driven planning approach that more fully addresses the challenges of these projects and delivered results that are aligned with project objectives."

Jan 1, 2015

By S. Makni, S. Koppalkar, A. Bouajila

ABSTRACT This paper briefly reviews the gravity recovery between conventional and centrifugal gravity separators. The advantages of semicontinuous gravity separators will be discussed, as will techniques for upgrading the gravity concentrates. The research efforts in optimizing semicontinuous gravity separators will be recalled. An innovative gravity circuit for eliminating or minimizing the use of complex processing schemes will be reviewed. Ongoing gold gravity research has revealed that gold particle shape transformation is one of the main factors explaining the lower recoveries of the plant units. Efforts to devise possible remedies for improving plant gravity recovery will be discussed.

Jan 1, 2013

By S. B. Kang

Magnesium has poor ductility at temperatures lower than 225°C and, as a result, Mg alloy sheets are produced via fairly complex thermomechanical processes consisting of numerous sequential steps of hot (warm) rolling with low reduction and intermediate recrystallization annealing operations. In context of the present study, a simple technology for the fabrication of magnesium sheets by hot (warm) rolling was applied to various magnesium alloys. The misch metal addition in those AZ alloys was done to evaluate the deformation behavior. Tensile tests were carried out for those AZ alloys after applying different heat treatments. The precipitation of ß phase (Mg17Al12 phase) induced different microstructures with various cooling method from solution treatment temperature, and also with various annealing treatment temperatures.

Jan 1, 2006

By John C. Luck Jr.

"DEVELOPMENT of oil emulsion mud dates back to the early days of rotary drilling when oil was added to the drilling mud solely for the purpose of freeing stuck drill pipe. After the drill pipe was freed, and drilling resumed, this oil was considered a contaminant. Efforts were made to remove the oil but some of it remained and was emulsified with the drilling mud, thus forming a mechanical emulsion.During the late 1930's, operators found that adding crude oil to drilling muds seemed to alleviate 'sticky-hole' problems and so oil was allowed to remain in the mud. This practice was adopted when it was found that faster drilling rates and longer bit life were obtained. These observations led to the development of emulsion drilling muds. During the past five years their application has become more widespread because of the lower fluid losses obtained, greater lubrication qualities, faster penetration rates, and generally better hole conditions.An emulsion may be defined as a two-phase system consisting of a mixture of either finely divided oil droplets in water or of finely divided water droplets in oil. The surrounding liquid is known as the continuous phase. The emulsifiers reduce the interfacial tension, making the droplets tend to repel each other so that they remain dispersed and stabilized. These emulsions are classified as oil-in-water or as water-in-oil, depending upon whether water or oil, respectively, is the continuous phase. Briefly, close inspection shows that they consist essentially of globules of• the one liquid suspended in a continuous mass of the other liquid. Oil emulsion muds are usually of the oil-in-water type. Two basic types of emulsifiers •commonly used in Canadian muds are soaps and lignites."

Jan 1, 1954

"Pilot plants for pressure hydrometallurgy represent special design and project execution challenges. Over the past twenty years, Zeton has designed and fabricated a variety of world-class pressure hydrometallurgical pilot-plant facilities, and this paper discusses design considerations and strategies related to such projects. Project execution methods are also discussed, and guidance is given for the selection of materials of construction and for the selection of appropriate pressure and temperature design points for pressure hydrometallurgical pilot equipment. The paper concludes with a discussion of the need for process similarity with future commercial operations and the realities of pilot-scale equipment.INTRODUCTIONThe process technology developer or owner and the designer/fabricator of a new pilot-plant facility are faced with some difficult technical choices even after the decision to build a dedicated plant has been taken. A pilot-plant project is usually on the critical path of a large commercial project involving investments many multiples greater than the capital cost of the pilot plant. Schedule savings in the design, manufacture, and commissioning of the pilot plant or in a rapid completion of the experimental program can be disproportionately beneficial to the overall development project. However, inappropriate shortcuts resulting in major oversights can be disproportionately problematic.A number of considerations and suggestions for both the project execution approach and the process engineering design of pressure hydrometallurgical pilot-plant facilities are presented as a guide for potential owners and operators of new pilot-plant equipment and facilities."

Jan 1, 2012