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By J. J. Jonas

The categories of interpass time encountered in hot rolling are characterized. These are shown to fall into three broad categories: short (in rod rolling); intermediate (in strip processing); and long (in plate schedules). The effects of interpass time on recrystallization and carbonitride precipitation are described, and particularly on the interaction between these two mechanisms. The interactions, in turn, determine the final microstructure produced as well as the mechanical properties.

Jan 1, 2005

By Pura Alfonso, Sarbast Hamid, Hernan Anticoi, Eduard Guasch, Josep Oliva

"Av. Bases de Manresa 61-63, Manresa (08242) Barcelona, SpainTantalum is a strategic metal and an improvement of the mineral processing is an important issue. The main objective of this work is to optimize the grinding technologies for tantalum ores with high pressure grinding rolls. The selected ore for this study was an altered leucogranite from the Penouta Open Pit Mine (NW Spain). In the present work mono-size experiments have been carried out using grinding rolls with controlled pressure. The particle size distribution has been monitored in the input and output of the high pressure grinding rolls for each experiment. The cylinder pressure that is transmitted to the particles has been determined. New population balance models are presented for high pressure grinding rolls with parameter adjust for tantalum ore. The obtained model uses the physical description of particles under the comminution action of the grinding rolls. The obtained results are in agreement with other models and the errors in the adjustment are low. The selection function proposed for this model describes adequately the breakage probability of the particles inside the high pressure grinding rolls. The presented model can be a good alternative for simulating a high pressure grinding roll process. INTRODUCTIONTechnology for grinding have been improved for many years, introducing new variables and parameters involving energy consumption, mechanical stress analysis of the compression particles or pressure application for optimizing the comminution (Morrell et al, 1997). High pressure grinding rolls is a modern technology that is proven to reduce the operating costs in full scale plants when compared with other milling technologies. Its benefits on energy saving and simplicity in the process have been studied and applied, first in the cement clinker industry (Abouzeid & Fuerstenau, 2009) and after in mining activities, especially in metallic ore deposits (Austin et al, 1991; Guevara & Menacho, 1992; Morrel et al, 1997; Torres & Casali 2009; Numbi & Xia, 2015). Many author structures of the High Pressure Grinding Rolls modelling in three main branches; (a) throughput modelling, (b) Power and energy model and (c) particle size distribution modelling (Austin et al, 1991; Guevara & Menacho, 1992; Austin & Trubelja, 1994; Morrel et al, 1997; Torres & Casali, 2009)."

Jan 1, 2016

By B. Coupal, F. D'Hennezel

Sorption measurements show that peat moss has much stronger affinity for oil than straw, which is currently used. Microscopic studies of peat moss show a highly porous and fibrous material, and this property, associated with the phenomenon of selective absorption, had been used to absorb oil. Laboratory experiments show that peat moss absorbs up to eight times its weight of oil. Field tests have proved that peat moss can be an effective absorbent and can be used on a large scale.

Jan 1, 1972

By D. K. Sarkar, Jiawei Xiong

"Self-assembled monolayers (SAM) on the aluminum substrates are used as the adhesion promoter between two aluminum substrates when bonded with the adhesive in adhesive bonding technology. Traditional surface analysis tools are not capable of identifying the presence of SAM on a surface; therefore, EIS has been used to determine their presence on the aluminum substrates. In this study SAMs have been deposited on aluminum using the monomer of (3-Glycidyloxypropyl)trimethoxysilane (GPTS) organosilane. AA6061 aluminum alloys substrates were chemically cleaned with NaOH and HNO3 to remove the native oxides, followed by immersion in silane solutions. In a second method, SAMs were prepared by applying a spin coating of silane solution to the samples. The prepared SAM coated aluminum samples were analysed by EIS in the three electrode corrosion cell using a diluted alkaline solution. The impedance of the SAM coated aluminum is found be higher than the as-received aluminum. It has been also observed that the open circuit potential (OCP) of the SAM coated aluminum is higher than the as-received aluminum. Both elevated values of the impedance and OCP confirm the presence of SAM on aluminum.INTRODUCTIONSelf-assembly (Schreiber, 2000) is defined as the spontaneous formation of complex hierarchical structures from pre-designed building blocks, typically involving multiple energy scales and multiple degrees of freedom. Generally speaking, SAMs are created by the chemisorption of ""head groups"" onto a substrate from either the vapor or liquid phase followed by a slow organization of ""tail groups"" of a molecule. Typically, head groups are connected to a molecular chain in which the terminal end can be functionalized with groups such as –OH, –NH2, –COOH, or –SH to vary the wetting and interfacial properties (Chauhan et al., 2007; Ulman, 1996; Vashist, Lam, Hrapovic, Male, & Luong, 2014). Though there exist several methods to prepare SAM (Chauhan et al., 2007; Chen, Yang, & Zhang, 2014; Cho, Park, Jon, & Choi, 2007; Igor Luzinov, 2000; Reis, de Melo, & Costa, 2006; Song, Zhai, Wang, & Jiang, 2006; Sugimura, Hozumi, Kameyama, & Takai, 2002; Vashist et al., 2014), the two methods vapor phase (Song et al., 2006; Sugimura et al., 2002) and solution(Chen et al., 2014; Igor Luzinov, 2000) are commonly used. Recently, many articles have been published on the fabrication of superhydrophobic surfaces with SAM technology (Cho et al., 2007; Pan, Shen, Shang, & Xing, 2012; Siddaramanna, Saleema, & Sarkar, 2014; Song et al., 2006). Brassard, Sarkar, and Perron (2011) successfully obtained a superhydrophobic film by applying fluoroalkylsilane via self-assembly on monodispersive silica. SAMs are also reported as good candidates for anti-corrosion and adhesion promotion (Chen et al., 2014; Saleema, Sarkar, Paynter, Gallant, & Eskandarian, 2012). However, papers on the characterization of SAM properties are rarely seen. The most commonly used substrate for SAM is silicon and the method implemented is scanning probe microscopy (SPM) such as atomic force microscope (AFM) (Igor Luzinov, 2000; Moores, 2011; Zhang, 2003, 2005). Igor Luzinov (2000) analyzed the epoxysilane SAMs’ surface morphology and microstructure properties using scanning probe microscopy (SPM) and ellipsometry on single-crystal silicon wafers. SAMs have been used to improve the adhesion bonding of aluminum or plastics but no characteristic data have been presented yet (Saleema et al., 2012; Telegdi, 2007; Wang, Xu, Luo, Wang, & Wang, 2009). Recently, Reis et al.(Reis et al., 2006) have studied SAM of alkane diphosphonate (Gardobond X4661) on Al 5052 alloy samples by EIS in a naturally aerated sodium sulfate solution."

Jan 1, 2016

By M. G. Lipsett

General Challenges for Mining & Mineral Processing Operations ? Capital-intensive industry ? Ongoing cost pressures ? Remote locations ? Workforce demographics ? Dynamic, unstructured, rugged environment

May 1, 2008

By E. Sigal

Overview ?Intrinsik has completed several wide area HHRA and ERA studies of mining and smelting communities ?Several ?Lessons Learned? ?Key areas related to: ?Study Design ?Data Quality ?Bioaccessibility ?Speciation ?Weight-of-Evidence Approaches ?Advances in Ecological Risk Assessment Techniques

May 1, 2009

? Introduction ? Partenariat MRNF - MAE ? Goldex ? Manitou : - Ré-aménagement du bassin versant - Accès aux zones problématiques - Filtration du ruisseau pour les travaux - Nettoyage près de la rivière - Régulation du débit et bassin - Digues et bassins - Déposition résidus Goldex ? Chemins d?accès Goldex-Manitou ? Pipelines: Goldex ? Retour Goldex ? Manitou ? Station de pompage ? Résumé

Feb 1, 2008

By G. Russo

During the construction of the S.Martin La Porte access adit, 9m in diameter, extreme squeezing conditions occurred while crossing Carboniferous schistose formations, with diametric convergence up to 2m. Back-analysis of monitoring results shows that an acceptable simulation of the observed excavation behaviour can be derived using a combined analytical and numerical approach, with simple elasto-plastic laws but a progressive reduction of residual parameters and a relevant increase of dilatancy.

May 1, 2009

By S. Perkins, E. Young, L. Dufour, K. McVey, L. Rolandi

This paper presents a review of plant layout considerations incorporated into recent designs of SAG/Ball mill circuits for two medium sized concentrators. The plant layouts presented and the design concepts discussed, relate to smaller SAG circuits, but can equally apply to larger milling circuits. Included are design concepts and ideas introduced by the various project teams, and the focus is on the primary factors of any layout design which are safety, constructability, operability, and capital cost.

Jan 1, 2012

By Mike McKevitt

We are trying to promote a concept and a change in management?s approach to the iterative process of grade control. This is important as grade control must routinely try and achieve the long term objectives set by the mine plan ??BackgroundBackground ??Factors contributing to variation from planFactors plan ??Basis of OptimisationBasis Optimisation ??Ore Block Optimisation processOre process ??Operating mine examplesOperating examples ??Chain of Mining. ??Intention is to highlight the need for repeatable and consistent materialand material-type classification to remain consistent with the Life of Mine Plan ??We can drill another hole or reWe re-optimise a plan, but once excavated, the final decision has been made ??The grade control decision is the last decision made in the resource exploitation sequence.

May 1, 2009

By Gerhard Kircbner, Boen Tan

"IntroductionThe Key Lake uranium-nickel ore deposits are located in the Athabasca Basin of northern Saskatchewan, Canada (Fig. 1). Many papers have been published on Key Lake in the past (Dahlkarnp and Tan, 1977; Kirchner and Tan, 1977; Kirchner et al., 1980). Immediately after its incorporation in 1968, Uranerzbergbau GmbH, a German holding company, set up exploration subsidiaries in Australia, the United States and Canada. This account reviews those exciting years starting with the concept to explore the rim of the Athabasca Basin in Saskatchewan, and leading up to the discovery of the deposits in 1975 and 1976.A few summary statements can be made:• The discovery of Key Lake resulted from a very systematic exploration approach and the persistence of Uranerz, the operator. • Cluff Lake and Rabbit Lake had been discovered some seven years before, but it was the discovery of the Key Lake deposits which brought Saskatchewan to the forefront to become Canada's foremost uranium producing province.• The experiences gained at Key Lake, which were subsequently published, triggered the discovery of many other deposits of similar, or even larger, size than Key Lake. The spatial relationship of those deposits to graphitic conductors and hydrothermal alteration zones are presently the most effective indicators for locating new deposits - indicators which were first recognized at Key Lake.• Key Lake is, and will remain for some years to come, the largest producing high-grade uranium mine in the world."

Jan 1, 1994

By T. Gonzales, M. Maleki, M. Caçador, B. Climenhaga, H. Ghorbani

The campaign life of furnaces in the copper making industry is greatly affected by damage caused by normal operation cycling and abnormal conditions. Proper monitoring and assessment of the existing conditions and safe remaining life of the vessels and their refractory lining is key to prevent an unplanned early replacement. This paper presents an industry-proven refractory management program as well as a typical fitness-for-service assessment of a rotary vessel shell in order to extend the campaign life of copper making furnaces and enhance safety. The furnace refractory management system involves a comprehensive audit and monitoring program which has been successfully applied to several copper flash smelting furnaces over the past 15 years. The fitness for service assessment provides a methodology to estimate the remaining life of the steel components by evaluating the existing damage and future damage rate based on the historical survey data. The above practices can provide the operator with cost savings by extending the vessel campaign life in lieu of implementing more rigorous refractory lining and shell audits. INTRODUCTION Primary copper smelting is generally divided into two categories of flash smelting and open bath smelting. There are many different types of vessels that can be used to convert the copper concentrate to blister copper including, flash, Mitsubishi process, TSL (ISA/Ausmelt), SKS Bottom Blowing, Anode and Teniente/Noranda furnaces, reactors, and Peirce Smith converters. Each vessel has its own complex and intense environment which requires careful refractory and steel design to withstand the severe thermomechanical and thermochemical attacks within its campaign life. The campaign life of furnaces is greatly affected by damage caused by normal operation cycling and abnormal conditions. Proper assessment of the existing conditions and safe remaining life of the vessels and/or refractory lining is key to prevent an unplanned early replacement. This paper presents an industry-proven refractory management program as well as a fitness-for- service assessment methodology to estimate the remaining campaign life of copper making furnaces resulting in cost savings and enhanced safety of the operating vessels.

Jan 1, 2019

By J. H. Archibald

"This paper describes the use of vector analysis for determining the intersection of mineral deposit veins. The mathematical evolution of the analysis is outlined.IntroductionMany mineral deposits can be characterized by sets of intersecting veins. Often a vein will have a steep dip and may intersect with another similar vein. Finding the intersections of these veins is usually done by graphical means. Structural geologists, by the methods of descriptive geometry, can usual ly predict where intersections of veins will occur. This method normally requires accurate drafting and layout of the problem and does not always lend itself to solution in the field.Another method for solving this problem involves the use of vector analysis, which is easily adapted to hand-held programmable calculators. It is assumed at the outset that the reader is familiar with the dot and cross products used in vector analysis. Two excellent references are cited at the end of this note for convenience.A plane, in general, is defined by three points. The points of interest here are the points where three vertical drillholes penetrate the vein, or plane, in question. The elevations of these three points are best referred to sea level. This requires knowing the elevation of the collar of the drillhole above sea level and the drillhole depth from the collar to the vein. The elevation of the intersection point is then found by subtracting the hole depth from the collar elevation. These three points now define the plane of the vein. A similar set of three points will define a second vein, and it is our object to show analytically their intersection if it exists."

Jan 1, 1983

By R. Sage, N. Rillette, M. D. Everell, G. Herget

"CANMET has been operating as a Government Technology Centre for two years. Many of CANMET's programs involve long-term research and require special expertise, often available at Canadian universities. CANMET's involvement with universities ranges from research grants and contracts to exchanges of scientists and joint use of research facililies. Examples of CANMET - university cooperation in mining are presented. IntroductionIn the last two years or so CANMET has undergone a significant metamorphosis, resulting in greater emphasis on applied research to enhance Canada's industrial capability. CANMET's new mandate is reflected in the types of projects undertaken and their categorization, (Fig . I). Emphasis is being placed on two project categories: strategic R&D, to enable CANMET to serve the changing technological needs of the industry; and incrernental R&D, to serve the more immediate industry needs through modifications to existing technologies and knowledge. The balance of CANMET's e ffor t is devoted to providing Mandated and Specialized Services, and to Exploratory Research.CANMET interaction with universities can involve one of several available vehicles : contracts, research grants, exchanges of scientists , student employment and nomination of professors on CANMET's advisory council. Instances of key university technical support to CANMET mining projects are highlighted."

Jan 1, 1990

By Dale Coffin

Definition Of A Crisis Crisis \kri-ses:\ An unstable or crucial time or state of affairs whose outcome will make a decisive difference for better or worse (Webster's New Collegiate dictionary) An event or set of circumstances that could significantly affect a company?s ability to carry out its business, damage a company?s reputation and/or threatens the health, safety and well-being of employees, the community or the public at large You?re Having A Crisis When... . The emergency poses a significant threat to the public or employees . The emergency situation provokes government scrutiny . The company no longer has full control of the situation . The situation has created significant regional, national or international media interest . The corporation?s reputation may be damaged or there is a threat to the bottom line or share value

May 1, 2004

By Desmond M. Connor

"The State of the EnvironmentRecent data from a State of the Environment report prepared in January 1991 and released in April (see references) , indicates that the physical and biological environment across Canada is deteriorating in some important ways. For example: • emissions and atmospheric levels of CO2 are rising at a rate more than 50% of the U.S. increase; global temperature continues to rise, especially during the last decade;• while S02 emissions have been falling since 1984, NOz has declined only slightly since that time; N02 in Canada rose 43% during 1970-87, compared with a 7% rise in the U.S.;• municipal discharges of phosphorus and BOD (biochemical oxygen demand) to fresh water have been rising steadily since 1983);• pulp and paper mill discharges to fresh and Pacific coastal waters have been rising, 1970-87;• migratory game bird populations (Prairie Mallard, Northern Pintail) have been declining for the last 20 years;• total per capita energy use continues to climb.The State of the PublicSimilarly, data from recent public opinion surveys shows that public concerns about the environment are either rising, or are remaining at a high level despite the competing claims of the economy and political events for attention.For example, Professor Reginald Bibby's national survey this year shows that Canadians rank our top three issues as theeconomy, the environment and government incompetence.An Angus Reid survey commissioned by the Mining Association of Canada and other mining organizations in 1989 showsthat, despite general support for its economic benefits:• 67% of the general public perceive the mining industry to be a major source of pollution and environmental contamination;• 68% believe that a new mine should not be developed if it will disturb local wildlife;• 52% would prohibit a new mine if it required a road through a national park;• 49% would disallow mine development if it took as much land as an average farm in an agricultural area or if it limited sports fishing in a local lake."

Jan 1, 1991

By Victor Rudenno

"Previous methods have employed statistical analysis to model future mineral resources. The method presented in this paper uses Zipj's Law to determine the size and grade of tin deposits still to be discovered. The law is applied independently to both known deposit tonnage and grades. A probability distribution for both 'tonnage and grade is computed/or those deposits still to be located and then, by applying a correlation between tonnage and grade, a distribution of the probability of metal content discovery is obtained.By considering an economic cut-off in metal contained in a deposit, the probability of economic success for the next tin discovery is computed, both for a world discovery and for the special case of Tasmania, Australia. The results indicate a probability of 11-37% on a world-wide basis and 18% chance of economic success in Tasmania.IntroductionIn the past , most attempts to determine the probability of success in finding an economic mineral deposit have relied on the accumulation of statistical data. These data are then used to predict a suitable frequency distribution to assess the probability of finding a deposit of a given size and grade (Singer,1975).The method not only relies on one having sufficient data, but also on the assumption that the data are not biased and that the distribution (usually log-normal) is a correct one. The method presented in this paper, to analyze tin deposits, uses Zipf's Law, which has been recently applied to oil, uranium, lead-zinc and gold deposits by Folinsbee (1977) and to Western Australian gold deposits by Rowlands and Sampey (1977). Tapp and Koniuszko (1978) have applied Zipf's Law to mineral distribution patterns in the Northern Australian orogenic provinces, which has enabled them to make predictions with a relatively small data source."

Jan 1, 1981

By P. E. Weidmark

"PART 1-Published PapersAllcott, G.A., and Archibald, D.E.; ""Description of pillar behaviour at Heath Steele Mines""; Can Min Metall Bull; 74:834:80-87; 1981.Baar, C.A.; Discussion of Theme 1: ""Physical properties of intact rock and rock masses""; Proceedings 3rd Congress Intnl Soc of rock Mechanics; 3:32-33; 1979.Baar, C.A.; Discussion of Theme 1: ""Physical properties of intact rock and rock masses""; Proceedings 3rd Congress Intnl Soc of Rock Mechanics; 3:37-38; 1979.Baar, C.A.; Discussion of Theme 1: ""Physical properties of intact rock and rock masses""; Proceedings 3rd Congress Intnl Soc of Rock Mechanics; 3:38; 1979.Baar, C.A.; Discussion of Theme 1: ""Physical properties of intact rock and rock masses"" ; Proceedings 3rd Congress Intnl Soc of Rock Mechanics; 3:41; 1979.Baar, C.A.; Discussion of Theme 1: ""Physical properties of intact rock and rock masses""; Proceedings 3rd Congress Intnl Soc of Rock Mechanics; 3:42; 1979.Baar, C.A.; Discussion of Theme 1: ""Physical properties of intact rock and rock masses""; Proceedings 3rd Congress Intnl Soc of Rock Mechanics; 3:46; 1979.Baar, C.A.; Discussion of Theme 2: ""Tectonophysics""; Proceedings 3rd Congress Intnl Soc of Rock Mechanics; 3:60; 1979.Baar, C.A.; Discussion of Theme 4: ""Underground openings""; Proceedings 3rd Congress Intnl Soc of Rock Mechanics; 3: 116; 1979.Baar, C.A.; Discussion of Theme 4: ""Underground openings""; Proceedings 3rd Congress Intnl Soc of Rock Mechanics; 3:116-117; 1979.Baar, C.A.; Discussion of Theme 4: ""Underground openings""; Proceedings 3rd Congress Intnl Soc of Rock Mechanics; 3:117; 1979.Baar, C.A. '; Discussion of Theme 4: ""Underground openings""; Proceedings 3rd Congress Intnl Soc of Rock Mechanics; 3:118-119; 1979.Baar, C.A.; Discussions (2) of Theme 4: ""Underground openings""; Proceedings 3rd Congress lntnl Soc of Rock Mechanics; 3:119; 1979.Baar, C.A.; Discussion of Theme 4: ""Underground openings""; Proceedings 3rd Congress Intnl Soc of Rock Mechanics; 3:120-121; 1979."

Jan 1, 1982

Terrane?s Canadian Assets Mt. Milligan, British Columbia Copper, gold (100%) Berg, British Columbia Copper, molybdenum (100%) Howards Pass, Yukon/NWT border Zinc (Option payments, and Royalty interest) Maze Lake, Nunavut Gold (Joint venture with Laurentian Gold Fields)

May 1, 2010

By Robert E. McIvor

"Use of the Bond Work Index to size industrial grinding equipment was widely known. Bond also described its application for measuring grinding circuit efficiency. Bond Work Index efficiency also has been used extensively by industry, but until now without concise standard methods, or a formal guideline, for doing so. The Bond Efficiency Sub-Committee of the Industrial Comminution Efficiency work group of GMSG has produced such a guideline, which is appended hereto. It covers the methods and provides examples of how to calculate the Bond Work Index Efficiency of most industrial grinding circuits. Bond Work Index testing equipment and methods are also provided.Comminution is responsible for a major portion of mineral processing plant energy consumption and operating costs. Bond Work Index efficiency provides valuable means, first, for benchmarking one’s plant performance against others in the broad industry, and hence defining the extent of the opportunity for improvement. Secondly, improvements in circuit efficiency with implemented changes can be quantified and monitored as part of continuous improvement efforts. These two important business activities are thus facilitated, and, in the absence of any other accepted method, otherwise would be lacking without the existence and application of this standard for comparison. While often loosely applied in the past by plant metallurgical staffs, the increased precision offered by this guideline provides much clearer definition of both the conceptual and statistical meaning of these measurements. Even a small improvement can be enormously financially important, but only if differentiated by measurement. This guideline was thus intended to provide industry improved means to differentiate comminution circuit efficiencies. Carbon footprint reduction is coincidental, but nevertheless can be substantial.The next steps are: (1) to establish standard reference testing materials and one or more laboratories to serve as bases for reference testing; (2) to establish the accuracy of relative circuit Work Index Efficiency determinations; and (3), to develop and provide a public data base of industrial comminution circuit Bond Work Index Efficiencies."

Jan 1, 2016