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By William E. Stanley

The paper examines the problems that arise in undertaking socio-economic impact studies to meet the requirements of environmental-impact legislation governing new mine development or expansion. An approach to undertaking socioeconomic impact studies is outlined, responses to specific problems are discussed and ways in which the mining company can use these studies to meet its general objectives are explored. The paper concludes by examining how a socio-economic study, as required by legislation, can be used to assist the mining company in achieving some general objectives it will have in developing a mine.

Jan 1, 1979

By Y. Feng

Perovskite structured oxide 15% Y-doped BaCeO3 (BCY15) has been evaluated for use as proton conducting electrolyte in SOFC with propane as the fuel and Pt as both electrodes. Under the fuel cell conditions, BCY15 exhibited high proton conductivity and good cell performances. Propylene was detected as product at the anode outlet, and the product distribution suggests that propane dehydrogenation underwent competition with cracking to lighter hydrocarbons. Stability during cell performance tests showed that there was no obvious degradation for BCY15 electrolyte during operation of C3H8-O2 fuel cell.

Jan 1, 2005

The Environmental Excellence in Exploration (E3) project is driven by the recognition that the minerals industry can only maintain its long term viability by ensuring its continued access to lands to explore for, and develop, new mines. Widespread implementation of sound environmental management practices by the exploration community and improved education and understanding of that by stakeholders will help substantially in accomplishing this, and E3 is designed to meet these needs. Exploration crews are now viewed as ambassadors for the global mining community. Their performance in managing the environmental aspects of an exploration program can demonstrate a commitment on the part of the international mining sector to environmentally responsible exploration and mining. We have all observed that failure to behave responsibly can alienate local residents, encourage anti-mining NGOs and jeopardize development. As the saying goes, ?you don?t get a second chance to make a first impression?, and we want to make a favourable first impression. The E3 project is focused on creating an electronic manual, the e-manual, which will provide rapid access to the most up-to-date information on environmental management practices for minerals exploration globally. The e-manual will reflect current thinking and practices in environmental management. It will be richly illustrated with actual examples that reflect the realities of exploration. It will strive to identify the key environmental issues and concerns that apply to most exploration projects, and identify other sources of relevant information useful to field practice. It is our belief that E3, or something very like it, is central to ensuring that the industry survives the current challenges to its viability. E3 will be a cornerstone of the mining industry?s drive to sustainability simply stated, if we are not permitted to explore for mines, there will be none of them at some point in the relatively near future.

May 1, 2002

By Stuart J. Schofield

Introduction The study of the ore deposits of British Columbia is one of fascinating interest not only from a scientific but also from a commercial standpoint and certain wide problems in connection therewith have interested me for some years. Several of these problems have been set forth in papers presented before this Institute on previous occasions. In 1918 it was pointed out that the commercial ore deposits of British Columbia, with one exception, were associated with the granodiorite batholiths of upper Jurassic age. This was followed, in 1922, by a discussion of the ore deposits of British Columbia in which the mineral belts of the province were defined and named, showing a zonal arrangement of ores in which the Pacific coast deposits are characterized by the presence of copper, while the interior belt is marked by the presence of silver, lead, and gold. Methods Of Investigation In reading various reports on the economic geology of British Columbia one is struck with the fact that the mineral veins may be arranged as a system and further examination will show that such a system follows two main directions, one northeasterly and the other northwesterly, both related in origin to the same force.

Jan 1, 1925

By A. Miura, G. Granata, C. Tokoro, A. Fuwa

"The high copper demand as well as the lack of new high-grade deposits, are pushing the copper industry to process low-grade and refractory ores containing chalcopyrite. However, for a quantitative dissolution of copper from the chalcopyrite, the leaching performances still need to be improved. In the present research, we studied and optimized the iodide-assisted leaching of chalcopyrite in H2SO4-Fe2(SO4)3 media. The evolution of surface species during leaching was determined by x-ray photoelectron spectroscopy (XPS) and mineral liberation analysis (MLA). Inductively-coupled plasma spectrometry (ICP-MS) was used to determine the dissolved copper. Significance of experimental results was assessed by statistical analysis while a kinetic analysis of the leaching process was performed by fitting the experimental data with the Shrinking-core model. Results showed the significant positive effect of iodide on copper extraction rate. In the presence of KI, the dissolution rate of copper was almost double than in the parallel experiments without KI. Whether using KI or not, elemental sulfur was generated on the surface of the leached chalcopyrite. Nevertheless, in the presence of KI, the passivation layer did not arrest the leaching. Analysis revealed that the leaching rate was limited by the chemical reaction control step.INTRODUCTION Due to the large demand of copper, processing low-grade ores containing copper sulfides such as chalcopyrite (CuFeS2) has become unavoidable (Watling, 2013). Since ores with CuFeS2 may also contain appreciable amounts of arsenic that cannot be smelted, and because low-grade ores are uneconomic to smelt, the hydrometallurgical technologies are crucial for recovering the copper (Dutrizac, 1978). Sulfate-based processes are attractive because of the lower operating costs and because the sulfate ion is more suitable in case copper would be recovered via electrowinning. In ferric sulfate solution, chalcopyrite undergoes oxidation due to the large amount of Fe(III) and dissolution due to the presence of the sulfate ion (Majima, et al., 1985). The leaching reaction in ferric sulfate medium can be represented as in (1):"

Jan 1, 2017

By L. T. Pasiechnyk

After a brief review of the various hydrocarbon storage methods currently being utilized and statistics on underground hydrocarbon storage, this paper will briefly describe the technology involved in solution mining salt to create caverns of engineered shape and size and briefly discuss the economical and environmental advantages of hydrocarbon storage in solution-mined salt caverns. Other possible uses of salt caverns will be mentioned.

Jan 1, 1978

By Jan Butra

Longstanding mining of copper deposits in the Legnica-Glogow Mining Basin, Poland has accumulated broad experience concerning the impact of geological and mining conditions on seismic and rockburst hazard. Methods of rockburst prevention for deep copper mines have been developed based on gathered data. Methods of rockburst hazard evaluation and rockburst control constitute a set of rockburst prevention measures. Due to their nature and location within the production process, prevention methods can be passive or active. Active methods of rockburst prevention consist of the liquidation of stresses in the areas where they are concentrated through controlled generation of rock-mass tremors and rockburst by blasting works (group extraction blasting, release blasting in the rock mass and pillars able to accumulate the stress, as well as in the roof and floor). Group blasting works as a basic method are very effective in copper mine conditions. Provocation of dynamic events makes it possible to control the timing of their occurrence. In Polish copper mines, all blasting works are made during the absence of miners in the mining fields. Daily distribution of both the number of recorded strong seismic events and volume of energy released, confirm the advisability of using this kind of rockburst hazard prevention. The rockburst hazard prevention methods developed over 40 years of copper deposit extraction are economically reasonable and offer sufficient effectiveness under high rockburst hazard conditions.

Aug 1, 2013

By M. Xian, M. Jahazi, Y. L. Lin

The 2-mm butt joints of ZE41A-T5 sand castings were laser welded at different defocusing distances on two surface conditions (as-cast or machined) using a continuous wave 4 kW Nd:YAG laser system at a power of 2.5 kW and a welding speed of 6.0 m/min. Two welding modes (conduction or keyhole) have been observed. The adjustment of defocusing distance can greatly influence the establishment of conduction or keyhole modes. On the machined surface conditions conduction welding is obtained at a power density of 4.0 x 105 W/cm2. In contrast, keyhole welding is reached at a threshold irradiance of 1.5 x 106 W/cm2. Neither conduction nor stable keyhole modes have been established at a range of power density from 7.7 x 105 to 1.2 x 106 W/cm2 on the machined surface conditions. On the as-cast surface conditions keyhole is obtained at a power density as low as 4.0 x 105 W/cm2 but good surface quality is obtained at a defocusing of +2 mm. The as-cast surfaces require lower power irradiance for the formation of keyholes indicating that they have higher energy absorptivity for Nd:YAG laser beams probably due to coarse surface morphology.

Jan 1, 2004

By Simon C. Dominy, Alwyn E. Annels, Paul Wheeler, Suzanne P. Barr, G. Simon Camm

Narrow veins are an important world-wide source of silver, tin, uranium and particularly gold. To potential ?nanciers, this style of mineralization is viewed as high risk because of the often relatively small resource involved and high cost of estimation. In many cases diamond core drilling will not enable resource estimation beyond the inferred and indicated categories. Exploratory under-ground development is required to de?ne measured resources. The de?nition of geological and grade continuity are major factors in narrow vein assessment. A measured resource must be based on strong geological and grade continuities. Narrow veins, generally less than 3 m wide, are complex geological phenomena, which commonly display unpredictable geometry and grade distribution. Variations in structural continuity, dip, strike, width, mineralogy and speci?c gravity are common. Veins may be composite, with ore-grade mineralization restricted to a speci?c structural domain. Branches, intersections and braided zones are common features. Potentially high-grade zones are often localized within ore shoots, which are surrounded by barren/low-grade regions. Resources must be determined as closely as possible to reality and re?ect the distribution of the commodity in the rock. Estimation has three main requirements: (1) geological study to determine orebody nature;(2) estimation of tonnage and grade, and (3) the presentation of this information using a classi?cation that is clear, unambiguous and bankable. Estimation methods employed are either classical or geostatistical; however, classical methods are often used because of the dif?culties in applying geo-statistics. Grades generally show a strong positively skewed distribution testifying the presence of high-grade values. Problems exist in the applicability of cutting outlier values risking over- or under-estimation of grade. It is generally believed that where resource estimates are in error, poor geological control is usually the cause. Overestimation can lead to the closure of a mine through lost revenue and capital. An understated estimate can result in an opportunity missed for pro?t and/or greater economies of scale. De?nition of reserves involves the consideration of economic and engineering data, to decide which part of the resource is economically mineable. Geology plays a similarly important role at this stage in the assessment of likely mining method, dilution, recovery etc. Throughout resource/reserve estimation, it is crucial that the amount and quality of the data and the geologist’s experience are relevant. The impact of geological understanding on estimation is often undervalued or assumed to be of lesser importance than ?nding grades and tonnages. This paper discusses the geology of narrow vein deposits and the importance of geology in their evaluation.

Jan 1, 1997

By Simon C. Dominy, Alwyn E. Annels, Paul Wheeler, Suzanne P. Barr, G. Simon Camm

Abstract-Narrow veins are an important world-wide source of silver, tin, uranium and particularly gold. To potential financiers, this style of mineralization is viewed as high risk because of the often relatively small resource involved and high cost of estimation. In many cases diamond core drilling will not enable resource estimation beyond the inferred and indicated categories. Exploratory underground development is required to define measured resources. The definition of geological and grade continuity are major factors in narrow vein assessment. A measured resource must be based on strong geological and grade continuities. Narrow veins, generally less than 3 m wide, are complex geological phenomena, which commonly display unpredictable geometry and grade distribution. Variations in structural continuity, dip, strike, width, mineralogy and specific gravity are common. Veins may be composite, with ore-grade mineralization restricted to a specific structural domain. Branches, intersections and braided zones are common features. Potentially high-grade zones are often localized within ore shoots, which are surrounded by barren/low-grade regions. Resources must be determined as closely as possible to reality and reflect the distribution of the commodity in the rock. Estimation has three main requirements: (1) geological study to determine orebody nature; (2) estimation of tonnage and grade, and (3) the presentation of this information using a classification that is clear, unambiguous and bankable. Estimation methods employed are either classical or geostatistical; however, classical methods are often used because of the difficulties in applying geostatistics. Grades generally show a strong positively skewed distribution testifying the presence of high-grade values. Problems exist in the applicability of cutting outlier values risking over- or underestimation of grade. It is generally believed that where resource estimates are in error, poor geological control is usually the cause. Overestimation can lead to the closure of a mine through lost revenue and capital. An understated estimate can result in an opportunity missed for profit and/or greater economies of scale. Definition of reserves involves the consideration of economic and engineering data, to decide which part of the resource is economically mineable. Geology plays a similarly important role at this stage in the assessment of likely mining method, dilution, recovery etc. Throughout resource/reserve estimation, it is crucial that the amount and quality of the data and the geologist’s experience are relevant. The impact of geological understanding on estimation is often undervalued or assumed to be of lesser importance than finding grades and tonnages. This paper discusses the geology of narrow vein deposits and the importance of geology in their evaluation.

Jan 1, 1997

By Ch. Enkhbold

Underground mining of minerals is becoming an increasingly complicated technological and ecological problem. It can be explained both by worsening of geological conditions of mining and by a specific character of mining industry, which, in contrast to processing branches of industry, intrudes into one of principal components of the nature ? the Earth's interior. At a traditional organization of mining industry, the entire volume of the produced rock mass is brought to the Earth's surface, where valuable components are extracted. This entails not only power over expenditure for long-distance transfer (especially in the vertical direction) of the waste rock forming a part of the original mineral, but also the formation of huge volumes of worked-out spaces. The latter leads (nature cannot stand emptiness!) to an irreversible development of geomechanical processes of shifting of overlying rock masses resulting in an irreparable damage of all surface structures located on the territory undermined by deep mining. Owing to their high productivity combined with low power consumption and instrumental compactness, novel bifunctional technological processes of minerals dressing successfully solve the problem of rock mass processing in underground conditions with subsequent operative disposal of final tailings of such underground dressing in the worked-out space. Besides, an integration of two processes into one is achieved, for example, a decrease in the rock mass coarseness with a simultaneous precise separation of valuable and waste components.

Aug 1, 2013

"Load-haul-dump machines (LHDs) are typically used in underground metal mining operations. Delays or inappropriate use of LHDs can result in production loss. Optimized LHD use is especially crucial in larger mines because longer travel distances increase heat, dust, and gas emissions, which in turn increase ventilation costs. This study, conducted at an existing Swedish sublevel cave underground mine, used discrete event simulation and the AutoMod™ DES tool to determine the ventilation costs related to using too many diesel LHDs in a production area with reduced ore pass availability. When fewer ore passes are available, ventilation costs related to operating LHDs in the production area were found to increase by as much as 200, 224, and 306% for one, three, and six LHDs in operation, respectively. ¦ KEYWORDS Discrete event simulation (DES), Loading operations, Production rate, Ventilation costs RÉSUMÉ Dans les exploitations souterraines d’extraction des métaux, on utilise généralement des chargeurs-transporteurs (LHD, de l’anglais Load-haul-dump machines). Les retards ou l’utilisation abusive des LHD peuvent entraîner une perte de production. L’utilisation optimisée des LHD est particulièrement importante dans les grandes mines en raison des longues distances parcourues, lesquelles augmentent la chaleur, la poussière et les émissions de gaz qui, à leur tour, décuplent les coûts de l’aérage. Cette étude, menée en Suède dans une mine souterraine utilisant la méthode d’exploitation en sous étages avec foudroyage, s’est basée sur la simulation à événements discrets (SED) et l’outil de SED AutoMod™ pour déterminer les coûts de l’aérage liés à l’utilisation d’un nombre trop élevé de LHD alimentés au diesel dans la zone de production, avec une disponibilité réduite de la cheminée à minerai. Lorsque les mines disposent de moins de cheminées à minerai, l’étude montre que les coûts de l’aérage liés à l’exploitation des LHD dans la zone de production augmentent respectivement de 200, 224 et 306 % pour un, trois et six LHD en fonctionnement. ¦ MOTS CLÉS coûts de l’aérage, opérations de chargement, simulation à événements discrets (SED), taux de productionINTRODUCTION Transporting material from the mine face to the dumping location requires flexible loading and hauling equipment that is able to cope with sharp curves and a complex mining environment. Load-haul-dump machines (LHDs) are designed for such an environment. Models are available to suit specific features of the working environment such as small, large, or narrow open stopes (Atlas Copco Rock Drills AB, 2007). When carrying a full load, haulage speed is higher for LHDs than for front-end loaders with the same engine size. Also, payloads are approximately 50% higher for LHDs than for front-end loaders (Atlas Copco Rock Drills AB, 2007). LHDs are capable of climbing steep (Bloss, Harvey, Grant, & Routley, 2011). The haulage distance between stope and ore pass is usually between 50 m and 400 m. LHDs are efficient for tramming distances up to 200 m (Bloss et al., 2011), whereas when loading trucks, the LHDs work efficiently when the distance is less than 100 m (Atlas Copco Rock Drills AB, 2007). The largest diesel-powered LHDs, with drive motors of up to 350 kW, can handle a payload of 21 t (Wennmohs, 2014). Most mining equipment runs on diesel fuel, which provides flexibility, high durability, and high efficiency (Pronk, Coble, & Stewart, 2009); however, other alternatives such as electric, hybrid diesel/electric, or hydrogen fuel cell machines are increasingly being developed and used. This change is due to diesel-powered machines accounting for a significant portion of the ventilation costs in the mine (Chadwick, 2008; Paraszczak, Laflamme, & Fytas, 2013). Currently, as part of the European sustainable intelligent mining systems (SIMS) project, Epiroc AB is planning to demonstrate technology for a diesel-free underground mine at Agnico Eagle’s Kittlä mine in Finland using"

Jan 1, 2019

By A M. Goodwin

Detailed stratigraphic studies in the Birch-Uchi Lakes area have shown that the volcanic components are arranged in superimposed sequences, or cycles. Each cycle displays a progression from predominantly mafic effusives below to predominantly felsic extrusives above. Sedimentary rocks are preferentially associated with the felsic extrusives. Two volcanic cycles are represented. The average stratigraphic thickness of the volcanic rocks present is 31,000 feet. The original volcanic pile was probably in the order of 40,000 feet thick. The present lithologic composition is estimated to be: mafic volcanic rocks, 60 per cent; felsic volcanic rocks, 27 per cent; sedimentary rocks, 10 per cent; and others, 3 per cent. Gold occurrences are preferentially distributed with respect to the volcanic succession. Of fifty recorded occurrences, thirty-nine are located in the upper felsic division of the lower volcanic cycle; forty are associated with closely interbanded daciterhyolite pyroclastic rocks, andesitic lavas and siliceous sediments. The gold-bearing quartz veins either lie at the contacts of enclosing lithologic units or occupy cross-cutting fractures in one or more adjacent units.

Jan 1, 1965

By Bert S. Hall

"The purpose of this paper is to review the evidence at hand concerning the earliest centuries of cast iron in Europe, from roughly 1400 A.D. until the second half of the sixteenth century. For the most part it is concerned with the relationship between two technologies which emerged first in China and then later appear in Western lands, gunpowder weapons and iron founding. We should not assume, as I hope to show later in this discussion, that weapons constituted the only product for which the iron founder had any market, but it is clearly true that attempts to produce weapons constituted the most severe technical challenge for the early founder. Firearms appear for the first time in Europe in the 1320s and develop into significant weapons on the field of battle by the end of the century. Theirs is a complex history, subject neither to easy summary treatment nor to simplified models of development. I hope to be able, through the analysis of the evidence concerning cast iron, to show that one important strand in the fabric of gunpowder's history concerns the materials from which cannon could be made. This question is subject to a number of shades of meaning, because ""cannon"" can be made for many purposes under a profusion of different names, and under sharply varying conditions of use. As a result, the question of materials is frequently really a question of competing materials, and involves a complex set of factors, of which production costs and the ultimate safety of the user seem the most important. Judged in this manner cast iron was an important but unsatisfactory metal for weapons purposes until 1543, at which time English founders learned to make iron muzzle-loading cannon which could rival bronze ordnance in most important performance criteria, but which cost much less to produce. With that event, the history of cast iron and the history of weapons entered into the close relationship that persisted until the advent of rifled artillery made of steel in the middle of the nineteenth century."

Jan 1, 1999

By I. Thobadi, C. Pawlik, K. Bisaka, S. Mokoena, M. Erwee

The PyEarth™ process developed at Mintek has been demonstrated successfully at pilot scale. Nine tons of ore containing 2.3 mass % of total rare earth oxides (TREO) from a dormant mineralogically complex iron-rich ore deposit, was subjected to a concentrating smelting step in a 200 kW DC open-arc pilot furnace and the rare earths from the resulting slag were extracted via a hydrometallurgical route. This ore deposit is practically not amenable to extraction by conventional methods. The testwork results proved that the PyEarth™ process was able to optimize the extraction of rare earths while minimizing waste through the removal of iron as a saleable iron alloy. Reduction of iron to the alloy in the smelting step was found flexible, efficient, and controllable, while rare earths were left virtually unreduced in the slag phase. The slag chemistry is selected to optimize both the smelting and leaching performances as well as the alloy composition. Leaching of the resulting slag was found possible and most efficient in hydrochloric acid amongst other lixiviants tested.

Jan 1, 2017

By The Mill Staff

"IntroductionCOMMENCEMENT of operations at the new No. 7 shaft and 10,000-ton mill at Creighton mine was a major step in the programme of conversion to all-underground mining by the International Nickel Company of Canada, Limited. Planned ten years ago, the orderly transition has been greatly speeded-up to offset the heavy drain on production imposed by World War II and also to meet the increased demand for nickel caused by the current international situation. Development of new mining methods, and process changes in the reduction plants, have made possible the economic recovery and utilization of ore of lower grade than formerly used and of varying metallurgical characteristics. By 1953, when the Company's open-pit mining operations are scheduled for completion, the hoisting capacity of its five underground mines in the Sudbury district will have been increased to 13,000,000 tons per year, compared with 5,700,000 tons of underground ore hoisted in 1950.Two types of ore occur at Creighton. One is a breccia and stringer type that contains a high percent-age of massive sulphides and is located in sheets along shears and in large and small pockets on the underside of the main norite mass; the other type, forming the main part of the ore zone, is mineralized norite that occurs as a •sheet up to 400 feet thick overlying tl1e breccia ore. In both types of ore the minerals of economic interest are pentlandite, which is intimately associated with pyrrhotite, and chalcopyrite. Early mining was confined to the breccia ore; this ore was mined by open stoping methods. The hanging-wall was later allowed to cave, with the result that the old stopes are now filled with caved low-grade ore."

Jan 1, 1952

"The technical report form provides the headings to be used and content required when a completing a technical report to be filed in accordance with NI 43-101. The technical report is meant to be a summary of the scientific and technical information on the mineral property. The Instrument (NI 43-101) requires that technical reports be filed with Canadian provincial or territorial securities regulators to support certain disclosure of mineral exploration, development and production activities and results in order to permit the public and analysts to have access to information that will assist them in making investment decisions and recommendations. FORM 43-101F1 TECHNICAL REPORT INSTRUCTIONS (1) The objective of the technical report is to provide a summary of scientific and technical information concerning mineral exploration, development and production activities on a mineral property that is material to an issuer.This Form sets out specific requirements for the preparation and contents of a technical report. (2) Terms used in this Form that are defined or interpreted in National Instrument 43-101 Standards of Disclosure for Mineral Projects (the “Instrument”) will bear that definition or interpretation. In addition, a general definitioninstrument has been adopted as National Instrument 14-101 Definitions that contains definitions of certain terms used in more than one national instrument. Readers of this Form should review both these national instruments for defined terms.(3) The qualified person preparing the technical report must use all of the headings of the items in this Formandmay create sub-headings. If unique or infrequently used technical terms are required, clear and concise explanations must be included. (4) No disclosure need be given in respect of inapplicable items and, unless otherwise required by this Form,negative answers to itemsmay be omitted. Disclosure included under one heading is not required to berepeated under another heading. (5) The technical report is not required to include the information required in Items 6 through 11 of this Form tothe extent that the required information has been previously filed in a technical report for the property being reported on, the previous technical report is referred to in the technical report and there has not been any material change in the information. (6) The technical report for development properties and production properties may summarize the information required in the items of this Form, except for Item 25, provided that the summary includes the materialinformation necessary to understand the project at its current stage of development or production. (7) The technical report may only contain disclaimers that are in accordancewith section 6.4 of the Instrument and Item 5 of this Form."

Jan 1, 2003

By J. F. Henderson

"IntroductionTHE National Advisory Committee on Research in the Geological Sciences was set up by the Privy Council of Canada in 1949. It was set up because you, the Geology Division of the Canadian Institute of Mining and Metallurgy, asked that it be set up. The Committee is, therefore, to a consider-able degree, your offspring. In the role of good parents you, of the Geological Division of the C.I.M., should be interested in the progress of your progeny. How is the Committee organized? What has it recommended? What has it accomplished? On behalf of the National Advisory Committee, that is what I want to tell you about this afternoon.HistoryYou will remember that, in 1946, the Geology Division of the C.I.M. set up a Committee on Geological Research. This Committee, under the Chairmanship of Dr. J. E. HAWLEY, found ""that there is no national organization interested in surveying, co-ordinating, and implementing with financial help, fundamental and much needed geological research. Accordingly, the first and most necessary step to put the geological sciences in Canada on a proper footing .is the recommendation that a National Advisory Committee on Research in the Geological Sciences be formed"" (l).This recommendation was endorsed •by the President and Council of the C.I.M. in 1947 and submitted to the Minister of Mines and Resources."

Jan 1, 1952

By S. U. Baltuch, E. G. Baltuch

"Ventilation in process buildings is key to proper mill function. Correctly engineered systems to evacuate surplus thermal energy from process areas allow optimized rates of air change, thus assuring the good functioning for the lifecycle of the process while demonstrating conformity with occupational hygiene standards. Computational fluid dynamic simulations, coupled with traditional calculations and physical modeling, can demonstrate to end users and assist engineers in the optimization of mill ventilation, reducing total installation costs while assuring that the proper solution is in place for the complete lifecycle of the process equipment. Results have been fully implemented on a number of steel mill and aluminium smelter applications and we continue to study, optimize, and innovate as new tools become available to provide the best possible engineered solutions for particular applications. INTRODUCTIONThe objective of this research project is the development and implementation of modern approaches and computational fluid dynamics (CFD) simulation in the engineering of green ventilation of hot process buildings. This will assure the predictive performance and improve the quality and ease of construction of industrial gravity ventilation equipment, along with the adjunct hot process buildings, while lowering the overall project costs and time to completion.In order for a hot process building, such as a steel mill, to properly function, heat must be extracted from within. This is accomplished by having air inlets at the bottom of the building and outlets at its apex. The reason for this is to maximize the potential chimney effect. When using stack (buoyancy) effect ventilation, the process heat becomes the driver. Therefore, increasing this distance (height) improves the ability of the heated airstream to utilize basic gravity for acceleration of the heat/air flow, allowing a regular number of air changes per hour while ensuring that the process environment remains weather resistant under normal operating conditions.This process has been understood since the time of King Charles I of England, who decreed in 1600 that buildings should have 10 foot ceilings and that windows should be made taller rather than wider to allow better smoke extraction.Figure 1 is a painting of the Bethlehem Steel Works in the 1860s, where the concept of air inlets and penthouses on the roofs for air outlet was already being put into practice. Figure 2 is an early photograph of the Pittsburgh Steel Works."

Jan 1, 2012

By N. Tounsi

The use of analytical modeling of continuous chip formation in conjunction with orthogonal cutting experiments was presented in the open literature to identify the coefficients of material constitutive equation within the practical range of stress, strain, strain rate, and temperature encountered in metal cutting. Identification of reliable constitutive data was hampered by a lack of a reliable model for the prediction of the primary shear zone thickness that affects directly the effective strain rate field. An original analytical model to determine the primary shear zone thickness is proposed in this paper. It is based on the mechanics governing the material flow in the primary shear zone. Based on the distribution of the hydrostatic pressure and the forces measured from orthogonal cutting tests, the model that describes the thickness of the primary shear zone is derived. To validate the model, FE simulations of chip formation using DEFORM3D were carried out for different materials and cutting conditions. The results of the analytical model are in reasonable agreement with FEM results.

Jan 1, 2006