Search Documents

By Mikael Ramström

The IREDES Special Interest Group (SIG) for Drill rigs has been active since its inception at MineExpo 2000, in Las Vegas USA. The SIG for drill rigs is responsible for the development of a IREDES Drill rig profile. This includes the exchange of production planning, performance and quality reporting data between various kinds of drill rigs and the databases used by the operating mine. During year 2001 a first draft of the drill rigs profile was jointly prepared by drill rig suppliers, mining companies and third party suppliers and reviewed during several SIG meetings. In mid 2002 the profile was released for prototyping projects and since then, feed back received from these projects has been used as input to the first official IREDES release. LKAB and Atlas Copco decided in 2002 to start an IREDES prototyping project using the Simba L6C production drill rig as target equipment. The goal was to verify the drill rig profile and identify possible problems prior to the official release. This was done by implementing the IREDES prototype version in the LKAB?s production planning system and Simba rig control system. The Simba rig control system was designed to handle drill plan and logging information coming from the mine planning system. In parallel to this the mine production system was adapted for drill plan export and logging data import on IREDES format. This paper presents the most recent results of this prototyping project. Result from late 2002 show that the basic architecture of the drill rig profile works and that a common language for data exchange, IREDES will be a central issue for future mine automation. As a result from this and other IREDES prototyping projects the official IREDES release will be available in 2003. Soon after that release IREDES compliant products can be expected. This will include drill rigs and mine production planning systems.

May 1, 2003

"ALTHOUGH Canadian metallurgists have long been active in research, the scope of the work was somewhat limited until the be-ginning -of World War II. The rapid industrial development of Canada during the past ten years has been accompanied by .a similar upsurge in research. However, the wide geographical distribution of the research centres has made it difficult for the individual research workers to meet together and to exchange ideas or even to learn what projects .are being investigated or the nature and extent of the facilities available for work of this kind.The purpose of the present symposium is to assemble data relating to projects under investigation and the facilities employed at the various metallurgical research laboratories in Canada, thus providing some measure of correlation so that workers in different locations may learn what kind of work •is being .done at other points throughout the country.In reporting the symposium it has not been possible to reproduce the papers in full, but excerpts have been selected that give the essentia1 data."

Jan 1, 1952

By A. S. Dawson

Introduction The purpose of this paper is to discuss, in a general way, the application of geological principles in the exploration for, and development of, deposits of industrial minerals. Mention of geological factors pertaining co specific minerals will be by way of illustration only. Since many prospectors are little acquainted with the geological setting and mode of occurrence of deposits of these minerals, some prospecting possibilities in the field will be pointed out. Geology is a tried and proven tool in the search for and exploitation of metalliferous deposits and of oil and gas fields, but, so far at least as Canada is concerned, only very rarely has a directed, intensive search been made for deposits of industrial minerals. Examples might be cited, however, where, in other countries, such investigations have yielded rich rewards. Thus, development of the vitally important potash deposits of New Mexico was the result of a deliberately planned programme of geological investigation, first by United States Government agencies, and later by private interests. War or the threat of war, or peace-time industrial expansion, can render concentrated exploration for specific minerals desirable or even essential. Such exploration is, primarily, a geological problem. Admittedly, there is in general less scope for the application of geology in the search for, and development of, deposits of industrial minerals than of metalliferous minerals, oil, etc. Where the latter are concerned; the objective of exploration is to find a material that is valuable, within broad limits, no matter where it is located or how it occurs. The unit value of the material is limited only by the amount of the valuable constituent in the formation- its possible upper limit is tremendously high. On the other hand, many industrial minerals constitute in themselves 90 per cent or more of the formation- their amount cannot increase and their unit value is commonly low. Moreover, for commercial exploitation, the deposit must, in general, be reasonably close to markets or to plant or other facilities for processing the raw material, since, owing to its low value, this cannot be transported any great distance. As a consequence, intensive geological search for and investigation of such deposits has been restricted to industrialized areas. Obviously, however, it is good insurance for any operator to understand the geological background of his deposit, particularly in the case of new developments.

Jan 1, 1949

By Du Xinfeng

The resource quantity of the low rank coalbed methane (CBM) accounts for 47% of the total resource quantity of CBM in China. Compared with the exploration and development of the high rank CBM in Qinshui Basin, China and the low rank CBM in Powder River Basin, USA and Albert Basin, Canada, the exploration and development of the low rank CBM are still in the initial test stage. In this paper, on the basis of analyzing the mining geological conditions such as that the Huanglong Jurassic Coalfield is largely situated in the hills and gullies zones, and the coal reservoir has the features such as the low metamorphic degree, large coal seam thickness, simple coal matrix texture, high permeability and small CBM content and so on, it discusses the key technologies such as the development pattern of CBM, well location arrangement, drilling and well completion technology and fracturing technology and so on. It indicates that the underbalanced drilling and the cavity well completion based on the reservoir protection will be the development directions of the CBM development technology in this area.

Aug 1, 2013

By M. J. deBastiani

The uranium producing division of Denison Mines Limited operates a 6,000-ton-per-day integrated mining unit in the Algoma area of Ontario. The property is located approximately one and one-half miles from Highway I 08, eight miles north of the town of Elliot Lake. The property was staked in 1953, diamond-drilled in ?late 1954 and 1955, and put into production in 1957. Since that date, the operation has produced $250,000,000 worth of uranium oxide from approximately 11,000,000 tons of ore milled, and paid $18,000,000 in dividends to its shareholders. The operation employs about I000 people, and monthly operating costs are approximately one million dollars. From these figures alone, it is obvious that it was necessary to develop and institute an adequate set ?of controls for effective management at all levels of supervision over a period of four years, a system of production and cost control was developed that enables us to effectively measure the pulse of the various phases of the operation at any given time.

Jan 1, 1963

By W. J. S. Craigen, G. E. Wittur

"In the context of today's continuously changing world, there are many factors which must be considered when attempting to assess the ability of Canada's primary copper producers to remain competitive in the face of increasing competition in world markets. In this paper, we have attempted to document those factors that will have the greatest impact on the future viability of Canada's copper industry, and to suggest possible strategies to fully utilize whatever inherent advantages Canada may have to enhance its competitive position. Technological factors related to the efficiency of precious and by-product metals recovery, energy type and utilization efficiency, production and sale of sulphur by-products, and control of 502 emissions are given high priority in this evaluation of Canada's future needs to remain competitive. Particular emphasis is placed on assessing the relative viability of hydrometallurgical versus pyrometallurgical processes for copper; to address uniquely Canadian conditions and problems. Due consideration is also given to the economic incentives required to allow Canada's copper producers to compete under anticipated world market conditions and to facilitate the continued development of Canada's copper resources. IntroductionWhen we try to assess the viability or competitiveness of any industry the bottom line is still usually, ""Can we produce a pound of product cheaper than the competition?"" Canada's copper industry is certainly no exception. However, as with most resource-based industries dependent upon exports, there are many factors which have a significant effect on the cost components which make up the total cost of producing and selling a pound of copper. It is desirable therefore to have as clear a picture as possible of the cost components, the major factors affecting them, and how they compare with the competition, particularly the third-world copper producers.In this paper we have attempted to provide a brief outlook for world copper markets and a brief overview of Canada's competitive position. We have also attempted to document those factors which will have the greatest impact on future production costs, and have suggested possible initiatives to utilize inherent Canadian advantages to enhance our competitive position. Special emphasis has been placed on technological initiatives designed to make full use of these ""advantages"", to develop superior beneficiation and extraction! refining technologies. Major factors considered in the present study are:"

Jan 1, 1986

By A. Coulombe

"RésuméL’analyse des séquences d’exploitation, actuellement en usage pour les gisements très inclinés, a démontré qu’elles ne sont pas toujours optimales du point de vue du contrôle des terrains et de la concentration des travaux d’abattage (nombre de chantiers simultanément en opération). Effectivement plusieurs séquences sont très propices à la création des nombreuses zones de hautes contraintes, qui sont à l’origine des effets de pilier. L’étude de cas de la mine Lac Shortt a démontré que certaines séquences d’exploitation, actuellement en usage, ne sont surtout pas adéquates dans le cas d’un état élevé des contraintes naturelles. En effet la mine a eu de sérieuses problèmes avec le contrôle des terrains (coups de terrains et les effondrements des épontes). Ces effondrements étaient responsables de la dilution excessive et des pertes importantes des réserves minières. Les deux nouvelles séquences proposées, visent la meilleure redistribution des contraintes d’exploitation en vue d’éliminer la création des effets de pilier. En plus elles permettent une concentration plus élevée des travaux d’abattage.À notre avis les séquences proposées pourraient améliorer substantiellement la stabilité des chantiers d’abattage et par la suite les performances technique et économique des opérations souterraines. ABSTRACTThe planning of underground mining sequences represents an important aspect of the mining operation. The analysis of mining sequences actually in use for very steep orebodies has demonstrated that they are not always optimal, considering ground control and the number of stopes simultaneously in extraction. These sequences are conducive to the creation in the rockmass of several stressed zones caused by pillar effects. The case study of Lac Shortt mine showed that the sequences of exploitation currently in use are not adequate especially in the case of a high state of the natural constraints. Indeed, the mine had serious problems with ground control (rock bursts and collapse of walls). These collapses were responsible for excessive dilution and significant losses of mining reserves. The two new sequences suggested aim for the best redistribution of exploitation constraints in order to eliminate creation of pillar effects. Moreover, they allow a higher number of stopes to be extracted simultaneously. In the opinion of the authors, the sequences suggested could substantially improve the stability of working areas and, thereafter, technical and economical performances of the underground operations."

Jan 1, 1998

By M. M. Williams

WESTERN CAN ADA'S coal industry has experienced a serious set-back since 1949, following a pattern well known to its counterpart in the United States. The loss in coal markets in Western Canada has been particularly severe as the discovery of large reserves of oil and natural gas and the subsequent construction of re-fineries and pipelines roughly coincided with the dieselization of both main railways. While the coal industry will have to face a further decline in markets of long standing, others with a large growth potential can be se-cured if present marketing methods are changed where needed and if fundamental and applied research programmes are actively pursued. The energy and chemical potential of Western Canada's coals will eventually find their place in the ever-growing needs of industry and electric power producers. Electric power generation would appear to offer the largest and most immediate market for coal. If the coal industry is to serve this market adequately and gain as much of it as possible, coal operators ? must have a good knowledge of certain characteristics -of the electric utility industry and its fuel requirements. This paper is prepared primarily to set out some of these characteristics, but also discusses other probable markets for coal.

Jan 1, 1958

By M. Rudolph, T. Leißner, TU Bergakademie Freiberg, C. Mämpel, R. Möckel, M. Embrechts, T. Leistner

Tin-mining activities have taken place in the region of the German Erzgebirge (Ore Mountains) for over hundreds of years up until 1991. For long times, gravity separation processes used to be the dominating beneficiation approach in those mining districts to recover cassiterite, the main tin-bearing mineral. For fine (< 100 µm) and very fine (< 20 µm) particles these approaches might not represent effective techniques, significant valuable materials could not be recovered and reported to tailings, where it was subsequently disposed. Thus, there are substantial amounts of cassiterite still present in these tailings disposals, most of it as very fine particles with already high degrees of liberation. That fact brings these tailings disposals into focus for potential reprocessing using beneficiation approaches, which are more sensitive to fine and very fine particles. In this paper we present results concerning the laboratory-scale treatment of material from exemplary heaps of the former Altenberg and Ehrenfriedersdorf mining sites using various flotation methods (including conventional froth flotation and oil-assisted flotation). Different size ranges of the material were previously prepared in order to investigate their response to the different techniques. For the study, special emphasis is put on agglomeration flotation, an oil-assisted flotation method. Therefore, an aliphatic oil phase of alkane basis is used to either selectively aggregate or collect the cassiterite particles. Recovery and flotation performance results are presented with respect to different process parameters: various collectors (including sulphosuccinamates and phosphonic acids) and depressants (including sodium fluorosilicate and oxalic acid) regime, oil dosage, agitation time and pulp density during oil/pulp agitation. Furthermore, the oil/particle aggregation behavior is analyzed via particle image analysis and, additionally, collector adsorption characteristics are investigated by contact angle measurements and zeta potential analysis. The data obtained is correlated with the testwork results achieved in order to interpret the flotation response of very fine cassiterite particles.

Jan 1, 2016

By Benoit Taillon

Contenu de la presentation 1. Le projet QMM et son contexte 2. Gérer la biodiversité 3. Résultats obtenus QMM QIT Madagascar Minerals S.A. ? JV: Rio Tinto (80%) et Madagascar (20%) ? Trois gisements: Mandena (en cours d?exploitation), Ste-Luce et Petriky (total 6000 ha) ? CapEx : USD 940M (Installations minières + port, énergie, routes, logement, écoles, cliniques, etc.) ? Technique par dragage des sables minéralisés et de concentration de l?ilménite (FeTi02) ? Exportation de l?ilménite pour son traitement.

May 1, 2011

By M. E. D. Raymont

"During the history of the sulphur industry there have been three distinct phases of production. Factors controlling supplies during these periods have shifted from demand for sulphur to demand for energy and a cleaner environment. The pattern of brimstone production is t raced through these phases and includes estimates of future supply; these indicate an involuntary excess production of some 20 million plus tons per year by 1980 unless some large-scale new uses are found. Traditional uses for sulphur, including fertilizer, chemicals, fibers, etc., are generally expanding slowly; how• ever, supply in ""by-product"" form alone will soon outstrip demand. The predicted oversupply situation can be corrected by the development of novel potential markets. Promising areas include construction materials, insulation and plastics, among others."

Jan 1, 1972

By N. Parnian

"Carryover of caustic soda (NaOH) in the steam path caused catastrophic failure of superheater 304H stainless steel tubes in a steam generator and led to an unexpected shutdown after just five months of continuous service of petrochemical following the start of production. The cause of the failure was studied, with a focus on the formation of sigma phase in the weld joint and effect of caustic embrittlement on stress corrosion cracking (SCC). The cracks were examined at the seam weld, heat affected zone (HAZ), and Ubend areas. Hardness was measured for the base metal, HAZ, and weld metal, and microstructures were examined using optical microscopy and scanning electron microscopy (SEM). Crack initiation is attributed to gouging on the precipitated carbide at the HAZ and also the formation of sigma phase in the weld metal, as shown by energy dispersive X-ray (EDX) analysis. In addition, cracking was propagated by caustic embrittlement because of residual stresses and hammering. Finally, the characteristic feature of fracture was illustrated by SEM fractography, and consists mostly of intergranular SCC and some quasicleavage transgranular. INTRODUCTIONThree key factors are needed for the initiation and propagation of intergranular stress corrosion cracking (IGSCC): a susceptible material, a corrosive environment, and sufficient stress. Although austenitic stainless steels are susceptible to sensitization and IGSCC, they are widely used in boiler and superheater tubes because of their high corrosion resistance, high oxidation resistance, acceptable mechanical characteristics at elevated temperatures, and low cost.Sodium hydroxide is injected to neutralize acidic constituents in the steam path, but caustic can concentrate in boiler tubes and attack the surface metal (known as gouging) even traces of caustic in the steam can deposit on surfaces and cause local concentrations of several percent (ASM handbook, 1992). Not only sensitized grains but also sigma phase formed in the weld metal can initiate caustic cracking. In this research, the cause of the failure of 304H stainless steel superheater tubes in a methanol petrochemical plant in Iran was studied with a focus on the effects of caustic embrittlement on IGSCC."

Jan 1, 2012

By H. -L. Heikkilä, E. Peuraniemi

"Boliden Harjavalta Oy has a long tradition in the Finnish metal industry starting from the 1930's. The Smelter consists of copper and nickel flash smelting lines. Off-gases are captured in the acid plant to produce sulfur products. During the early years of production, the surrounding environment suffered from high SO2 and dust emissions. The first acid plant started in 1947, a few years after commissioning of the smelter. The flash smelting method was developed and commissioned in 1949. This created the basis for today’s environmentally sound metal production. Recent air emission reductions are related to treating lean ventilation and granulation gases. Emissions from the stacks are monitored with continuous measurement devices. SO2 and PM10 concentrations are also measured from the residential area and reported online in cooperation with Harjavalta community and other local industry.INTRODUCTIONProductionBoliden Harjavalta Oy smelts copper and nickel concentrates and refines copper in the western part of Finland. The copper concentrates come from external copper mines mainly in South America and Europe. Concentrates are unloaded at the Pori harbor and transported to Harjavalta by train from a distance of about 60 km. Boliden Harjavalta Oy has operations in Harjavalta and Pori. The smelter in Harjavalta produces copper anodes that are transported via railway to the copper refinery in Pori. The anodes are electro-refined into copper cathodes and by-products like Se, Ag, Au and Pt/Pd concentrate. In the Harjavalta smelter SO2 containing gases are delivered to a sulphuric acid plant where sulphuric acid and liquid sulphur dioxide are produced.Our nickel smelter smelts nickel concentrates on a tolling basis to produce nickel matte for customer needs. SO2 containing off-gases are delivered to the sulphuric acid plant for sulphur capture and modification into products.All our operations are certified according to the Quality, Environmental and Occupational Health and Safety Standards ISO 9001, ISO 14001 and OHSAS 18001. Boliden Harjavalta Oy was the first company in Finland operating in the metal and technology industry to be certified according to the Energy Management Standard EN 16001, currently this certification is done according to ISO 50001."

Jan 1, 2012

By S. Kivrak

The firms in construction industry could not sufficiently adapt the rapidly emerging information technologies in recent years into their corporate structures. Therefore, in an effort to further exploit the benefits of information technology (IT), integration of the experiences and backgrounds of construction industry and the advantages of IT, is one of the most open-ended fields for improvement in this industry. Utilization of IT in the construction sites will positively affect the efficiency, productivity, quality and health & safety issues in the construction sites thus the cost and completion time of the projects. Within this context, augmented reality technology, which brings a new perspective into IT, can be put into the service of construction industry. Augmented reality which has been designed to improve the services in many application domains such as school education, military warfare, military trainings, industrial maintenance, retail and medical, can be defined in the simplest form as augmenting the real world with information from the virtual world. The main aim of this study, which presents an overview of an ongoing project, is to develop an innovative method by making a construction worker, foreman, equipment operator or a site engineer watch a very comprehensive and informative animation which will enable the said staff to perform or supervise all the phases of the activity he or she is in charge for in a more efficient, productive, safer and qualified manner by means of smart glasses using augmented reality systems. In this respect, training material related with the activities in the construction sites will be prepared and with a well-fictionalized scenario, animations exhibiting all the phases and details regarding the related activity (e.g. masonry, formwork and rebar works etc.), method of statement, correct and incorrect applications in comparison-wise manner, will be produced. Therefore, the user will be able to reach the training material, method statements etc. in the animations about the activity he or she is in charge for, enabling him or her to figure out the work as prescribed in the specifications. Basic trainings about the system will be given to target group, i.e. construction workers, foremen, operators, site engineers and managers working in the construction sites to apply the system on sites after all the system was tested. After the testings, to determine the effectiveness of this system, semi-structured interviews and survey questionnaires will be conducted among the mentioned target group. Therefore, the potential benefits of this system to the construction industry can be determined. The main target of this study is to implement an efficient, thorough construction management by orienting the staff in the construction sites to perform efficient, safe and qualified works by means of smart glasses that use augmented reality. There are relatively few studies about the implementations of augmented reality technology in construction. The outputs to be attained in the end of the study have the potential of improvement of time, cost, quality and safety parameters by ensuring a qualified, safe, efficient and productive construction management via augmented reality technology in the construction industry.

Aug 1, 2013

By M. A. Stogran-Baker, S. Cole

"Fluorspar mining occurred in the St. Lawrence area from the 1930s until the mid 1980s. In 2013, CFI discovered a new ore body, the AGS vein, which proved amenable to more economic open pit mining methods. A new mill was designed to produce 200,000 tonnes per year of high quality, acid-grade fluorspar concentrate. The simple mill flowsheet includes crushing, dense medium separation (DMS), grinding, sulphide flotation, pulp thickening, fluorite flotation, thickening, and concentrate filtration. The type of flotation cell used is being installed for the first time in North America. Site clearing commenced in the spring of 2016, followed by mill building erection completed by the fall of the same year. Civil and mechanical installation as well as site-wide construction was completed by the end of September 2017. Commissioning commenced, and at the time of paper submission mill production is on track to ramp up to full capacity by the beginning of 2018. This paper will focus on the use of fluorine NMR analysis applied to fluorite and the development of on-stream analysis, flotation cell selection and the decision to install the new cells, and the water control program designed to maintain process control with the least possible environmental impact.HISTORY St. Lawrence is located on the south-eastern coast of the Burin Peninsula in Newfoundland and Labrador. The first occurrence of fluorspar in the St. Lawrence area was recorded in 1843 by British geologist J.B. Jukes (DNR 2010). Fluorspar was likely extracted in small quantities prior, however commercial fluorspar mining did not commence until 1933 at the Black Duck Mine. The Black Duck Mine operation processed ore by washing and screening – acid-grade was hand-picked from the oversize, the undersize was sold as a lower grade product. The Black Duck Mine was closed in 1941 (Wilson 2010). The American Fluorspar Limited (New Fluor) commenced operations on the Director vein in 1936, and was bought by Alcan in 1942 (Cooper 2012). Alcan also developed the Iron Springs as well as the Tarefare deposits. The Black Duck Mine mill had closed, and a new mill was built. This new mill crushed the ore prior to dense medium separation, the sinks of which were sent to Quebec for use in Alcan’s aluminum smelter (CFI 2016). Alcan shut down it’s mining operations in 1977 due to the dropping price of fluorspar as well as labour disputes. In 1986, the British-based Minworth Limited began producing ore from underground at Blue Beach North and Blue Beach South, as well as from open pits at Tarefare and Director veins (Cooper 2012). A new mill was built by Minworth in order to process the ore using flotation to produce an acid-grade concentrate. The low price of fluorspar caused Minworth to shut down operations in 1990. Whilst exploration has been ongoing, no mining had occurred in the area since 1990."

Jan 1, 2018

By A. McLean, X. Men

"With high quality sulphide ores diminishing, nickel production from low-grade oxide ores becomes increasingly important and a major concern is the high sulphur level in the resultant ferro-alloy. So, desulphurization of the ferronickel becomes an important consideration. Red mud is a waste product of alumina industry and causes adverse effects on environment. In the present study, experiments were conducted to determine feasibility of using red mud as a major ingredient of refining fluxes for ferronickel desulphurization. In view of their influence on slag-metal separation, contact angle measurements between ferronickel alloy and molten slag made from red mud were also determined. INTRODUCTIONNickel is a very important metal that finds a variety of applications including consumer products, building, automotive and electronics. There are two kinds of ores containing nickel, namely oxide and sulphide ores. Anthony and Flett [1] reported that about 55% of the world’s nickel production originates from sulphide ores while the balance of new nickel is derived from oxide ores. However, oxide ores count for about 70% of the worldwide reserves. Apparently, oxide ores will play a significant role in the production of nickel in the future. Most of nickel produced using oxide ores is from pyrometallurgical processes namely ferronickel smelting or matte smelting. So, we can draw such a conclusion that using nickel oxide ores to produce ferronickel will become more and more important .Before used to make stainless steel or other materials, the ferronickel need pretreatment to remove impurities especially sulphur and phosphorus that will cause negative influence on the properties of steel product. Red mud is a by-product during alumina production. Usually, about 1 to 1.5 tons of red mud will be produced when we get 1 ton of alumina. About 90 million tones of red mud are produced every year in the world [2].Red mud is deemed as a toxic industrial waste which needs treatment before discharge because of alkalinity and chemical and mineralogical properties. Until now, the main means to deal with red mud are to store it in impoundments or dump it in the sea depending on local environment. Nowadays, how to recycle red mud has become a pretty hot topic around the world. The last 40 years have witnessed a lot of patent applications concerning the ways of red mud utilization. However, a little amount of red mud is consumed until now due to the limitations of recycling red mud."

Jan 1, 2012

By G. H. Blackwell

Open pit mine management must ensure that sufficient trucks are available and are being used effectively for production, and that operating costs are under continued control and review for improvements. This paper describes methods for estimating truck fleet requirements which have been used effectively at large- and medium-sized open pit mining operations. Applied to commonly available data, multiple regression analyses can indicate when mine plans should be revised toward optimizing the number of trucks required. Prediction of major cost items for budgetary purposes is addressed, along with an example of how readily available production data can be used to reduce costs systematically.

Jan 1, 1999

By N. J. Shackleton, N. A. Chapman, V. Malysiak, C. T. O’Connor

In this study, the effect of using conventional crushing and high-pressure grinding rolls (HPGR) in combination with dry or wet milling was investigated using a base-metal sulphide (BMS) sphalerite and a platinum group mineral (PGM) ore to determine how these processes affect the flotation performance. In sphalerite, irrespective of the crushing procedure (HPGR or conventional), dry milling resulted in the highest grades and recoveries of zinc, whereas in PGMs, similar treatment produced the poorest results. The results were investigated further by the effect of factors such as percentage liberation and particle size on the flotation results.

Jan 1, 2012

By Andrew J. Freyman, George S. Barry

"Mineral endowment in northern British Columbia and the Yukon Territory was assessed on the basis of geological opinion which was gathered in a quantitative framework of subjective probabilities. The survey area encompassed 364,000 square miles and was divided into 310 cells having dimensions of one degree of longitude by one-half degree of latitude. The response solicited related to tonnage, grade and number of deposits of a particular mineral in each cell. The questionnaire sought an expression of mineral endowment down to mine-able depth as distinct from economic expectations. Details on the questionnaire and responses are presented in a series of contour maps on individual commooities, which illustrate the collective occurrence picture of the respondents. The approach is largely dependent on the cooperation of an adequate number of geologists familiar with the region being examined. This approach to an assessment of the mineral endowment of a region has a wide range of applicability, from the focusing of exploration effort to aiding government and development bodies in the formulation of regional strategies and the planning, for example, of road, rail and power facilities."

Jan 1, 1970

By M. Elmadagli

Wear mechanisms of two commercial aluminum alloys, namely a spray formed and extruded Al-25%Si alloy, and a sand cast A390 alloy (18.5 %Si) that are known to be successful in cylinder bore technology were studied to have a better understanding of the requirements for wear resistant aluminum alloy design. From durability point of view these alloys are known to be successful for engine bore applications. It is interesting to compare the wear mechanisms in these alloys because they have significantly different silicon content and microstructures, and were produced using different techniques. The wear tests were done using a block-on-ring configuration, in controlled air atmospheres (5 % relative humidity). In spite of the differences in silicon content and microstructure, the wear mechanisms were similar and consisted of formation and destruction of hard tribolayers that are either formed by either mechanical or chemical interactions on contact surfaces. The differences in the wear rates between the two alloys arose from the differences in the hardness of the worn surfaces, and the alloy&apos;s ability to sustain the tribolayers on the worn surfaces.

Jan 1, 2004