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By Bruce Peberdy

Outline ?Building Systems ?Climatic Effects ?Thermal Effects ?Building Components ?Building Materials ?Structural Deterioration ?Maintenance Considerations

Nov 1, 2011

By Peter Van-De-Velde

"The results of applying Japanese pumping technology to North American reclamation projects will be discussed.IntroductionEconomic high-density mineral reclamation and subsequent transportation of solids through a pipeline presents many formidable engineering problems.In North America where space has rarely been a facto r, industry has generally relied upon the traditional dumping of material into various waste ponds, etc . In Japan, where confined geographies and stringent environmental regulations are enforced, alternative solutions for disposal or reprocessing of waste material had to be found.High-density mineral reclamation system designed by theoretical formulas is almost impossible because solids composition, i.e. concentration, velocity, moisture content, solid size, etc. can only be controlled within a broad pumping range.Traditionally this has restricted dredging of material to relatively dilute slurries whereas it is usually preferred to reduce water usage with its associated power and reclamation costs to a minimum and reclaim as high a concentration as possible.At Toyo Pumps North America we recognized these pumping limitations and began to develop and manufacture a range of standard and auxiliary equipment that would exceed these technical restrictions."

Jan 1, 1985

By K. J. Mintz

Conveyor belts installed in an underground mine can be a potential source of a major fire, thus the need for fife-retardant belting. A Canadian Standard, CAN/CSA-M422-M87, incorporating a small-scale flame test, a drum-friction test, a flame propagation test and an electrical surface-resistance test, has been developed to meet the varied needs of the mining industry. It is recommended that mines use Types A and B belting described in that Standard, because they will have passed the large-scale flame propagation test, rather than Type C, which does not require that test. Belting that has been approved by the U.S.A. Mine Safety and Health Administration (MSHA) may be much less fire-retardant than any Canadian approved belting.

Jan 1, 1992

By H. Somekawa

The fracture toughness and deformation structures an AZ31 magnesium alloy processed by equal-channel-angular extrusion (ECAE) were investigated. The average grain sizes of as-ECAE and annealed-ECAE alloys were 4.0 and 16.3 µm, respectively. The plane-strain fracture toughness, Kip, in as-ECAE and annealed-ECAE were estimated to be 27.3 and 23.5 MPam1/2, respectively, by stretched zone analysis. The fracture toughness indicated higher value with grain refinement. From optical microstructural observations in samples after fracture toughness tests, although deformation twins were observed in annealed-ECAE, no deformation twins were observed in as-ECAE. From TEM observations, the dislocations on basal and non-basal planes were activated in as-ECAE. With grain refinement, the activations of dislocations on both basal and non-basal planes were possibly related to the reduction in formation of deformation twins in as-ECAE. In addition, in comparison with direct extruded process, ECAE process was more effective method to improve the fracture toughness in magnesium alloys.

Jan 1, 2006

By B. Lewis

Paper did not make deadline for printing

Jan 1, 1982

By P. E. Weidmark

Allard, M., Hucka, V.J., Das, B., and Borchtch-Komponietz, V.I., "Investigation of seismic vibration due to large blasts in Gaspe Copper Mines"; (in Russ); The Industry of Chemical Raw Materials; Referativnyi sbornik; 5:18-20: 1978. Askew, J., McCarthy, P.L. , and Fitzgerald, D.J ., "Backfill research for pillar extraction at ZC/NBHC"; Mining with Backfill; Proc 12th Cdn Rock Mech Symp; May 23-25, 1978; Sudbury; CIM Spec Vol 19:100-lJO; 1978. Barrett, J.R., Coulthard, M.A., and Dight, P.M., "Determination of fill stability" ; Mining with Backfill; Proc 12th Cdn Rock Symp; May 23-25, 1978; Sudbury; CIM Spec Vol 19:85-91; 1978.

Jan 1, 1979

By D. M. Maijer, S. L. Cockcroft, A. B. Phillion, P. Fan, C. Reilly

"A numerical model has been developed to study macrosegregation associated with liquid feeding in the Low Pressure Die Casting of A356 aluminum alloy wheels. The model of the wheel casting process has been implemented within the commercial CFD software package, FLUENT, using a User Defined Function (subroutine) to account for Si rejection based on the Scheil approximation. The model has been validated against temperature and microstructural data taken from a commercially cast wheel. The amount of segregation in the wheel has been shown to be significant in a couple of key areas. The implications of accounting for segregation include an improved ability to predict shrinkage porosity, fatigue performance and potentially also hydrogen porosity.INTRODUCTION The aluminum alloy A356 is widely used in the automotive and aerospace industries for various components. Examples include automotive wheels, automotive suspension components and airframe castings. Focusing on automotive wheels, Low-Pressure Die Cast (LPDC) A356 wheels offer significant design freedom and are far more aesthetically appealing to consumers than conventional stamped steel wheels. A356 wheels now dominate the market, appearing in all but the entry level offerings of the OEM manufacturers. However, they are typically over-designed to allow for the various casting related defects that degrade their mechanical performance. Thus, their potential to save weight has not been fully realized. Wheel manufacturers are under constant pressure to ensure their products meet strict mechanical requirements (ductility, fatigue, vibration), tight geometric tolerances and high aesthetic quality. The mechanical properties of the final product are determined by the microstructure – e.g. SDAS – and the defect population (porosity and oxides). Depending on their size and location, both porosity and oxides, can act as crack initiation sites reducing fatigue life (Caton, 2001; Jordan, 2010; Wu, 2015). There are a number of examples appearing in the literature (Atwood, 2000; Carlson, 2007; Lee, 2001; Yao, 2011) of numerical models that have focused on hydrogen-based pore formation that have demonstrated an ability to predict porosity formation and pore size distributions in geometrically simple castings. These models assume that the local gas species diffusion through the liquid metal to the pores is the rate-controlling factor of pore growth. Another common source of porosity is liquid encapsulation (Dantzig, 2009). As the pressure within the isolated liquid drops, pores form first due to the pressure dropping below the equilibrium partial pressure of hydrogen in solution and then second grow substantially as the pressure continues to drop falling below the vapour pressure of Al. One factor that can affect both mechanisms of pore formation is species macrosegregation, which has received comparatively little attention in die-casting."

Jan 1, 2017

By W. J. Li, L. Kong, G. L. Li, X. M. Xi, J. Qiu

"A novel hydrothermal method was applied to prepare the precursor of LiMn2O4 using pre-treated electrolytic manganese dioxide (EMD) and lithium hydroxide as the main raw materials. The precursor was subjected to heat treatment between 400 and 900ºC to obtain spinel Li1.05Mn1.95O4 and Li1.035Co0.035Mn1.930O4 positive materials for lithium ion batteries. The structure and morphology of the obtained powder materials were studied in detail by means of X-ray diffraction (XRD) and scanning electron microscope (SEM). It is found that the precursor has an amorphous structure and a high reactivity, which is easily transferred to spinel structure during heat treatment, obtaining a positive material with an uniform structure and good performances. The XRD patterns reveal that single phase spinel Li1.05Mn1.95O4 can be obtained from the precursor after heat treatment at 600°C in air. The final Li-rich Li1.05Mn1.95O4 product obtained showed a well-defined stable spinel structure and distinctive crystal faces with particle size between 200 and 300 nm. The as-prepared Co-doped spinel sample exhibited a excellent electrochemical performance with an initial discharge capacity of 113.0 mAh/g and 93.8% of its original value was retained after 100 charge-discharge cycling at 0.5 C.INTRODUCTIONThe increasing demand for portable electronic devices and hybrid or full electric vehicles is driving the development of cheap, efficient, compact lightweight and environmental friendly rechargeable batteries systems (Chung et al., 2002; Scrosati, 1995). Lithium ion secondary batteries have satisfied this demand to a greater degree than other battery systems. The cathode material plays a critical role in the performance of Li-ion batteries. The high cost and toxicity of cobalt compounds for the cathode material of LiCoO2 has prompted a search for alternative materials. LiMn2O4-based spinels offer a potentially attractive alternative to LiCoO2, due to its abundance, low price, ease of preparation, environmentally friendly characteristics, better thermal stability, and its effortless recycling (Tarascon et al., 1991; Yabuuchi and Ohzuku, 2003; Amatucci et al., 1999; Tsai et al., 2003). Some achievements have been created to meet the requirements (Guo et al., 2010; Kang et al., 2005; Park et al., 2008; Takahashi et al., 2006; Lee et al., 2001; Yoshio et al., 2001; Arumugam et al., 2008). However, the largest obstacle encountered in the practical applications of LiMn2O4 is its fast capacity fading during long term cycling, which is due to Jahn-Teller distortion of the [MnO6] framework, the electrolyte decomposition at high potentials and manganese dissolution into the electrolyte (Fey et al., 2003). The electrochemical performance of LiMn2O4 is also strongly dependent on its morphological properties, such as crystallinity, phase purity, surface area, grain shape and particle size distribution, etc. All these morphological properties are closely related to the material synthetic routines and heat treatment processes (Huang et al., 2000; Myung et al., 2000; Takada et al., 1998)."

Jan 1, 2012

By S. Dessureault

The relatively recent explosion of available data in all business sectors has induced a common expression of “drowning in data, starving for information.” The mining sector is affected by the information age through equipment-based sensors, process monitoring, and traditional enterprise data sources. Information technologists have developed techniques such as data mining that apply new and old statistical algorithms to large datasets. Mine planners and managers can apply these tools for improved planning and control, thereby increasing the use of the highly underutilized information system infrastructure in most modern mines. This paper describes the use of data mining and its enabling technology, data warehousing, in the development of an energy consumption model for large surface mines using real historical data.

Jan 1, 2007

By Joanne G. Petrini

ISO 26000 Unique Process Unique Personality ?Almost 10 years in the making ?What type of standard is this? Different type of ISO Standard ISO 26000 Structure and Substance ?Principles ?Core Subjects ?Implementation Guidance ISO 26000 Impact ?Same old, same old? ?So Is there really anything NEW? ?Should I care??

May 1, 2011

By Ian McC. Stewart

"Seam gas flow in coal mines takes place through a medium which has both capacity and resistance and can therefore be expressed in terms of the basic diffusion equation, provided that the characteristics of the system can be adequately described. It may be possible to lump the variations from point to point in a seam together as an effective diffusivity. The paper discusses the characteristic flow-time patterns for various types of openings and the particular features of coal and seam which influence the diffusivity.Two field experiments are described in which gas make to a heading and to a borehole were measured in a mine for which considerable data on coal sorption properties were available. Incremental gas flow measured from the borehole experiment predicted the actual flow from the heading measurements remarkably well. The effective permeability adjacent to the face was much higher than expected from the properties of the coal. The incremental flow measurements to a horizontal (in-seam) borehole showed a striking picture of advancing 'relaxation' behind the face which is not discernible by other experimental means."

Jan 1, 1971

By P. Trudel, M. A. . Cloutier

This lithogeochemical study demonstrates that the Gilman and Blondeau Formations in the Chibougamau area belong to a subalkaline suite of tholeiitic affinity poor in potassium. The Gilman Formation is composed mostly of basalts, with subordinate andesites and rare dacites, while the Blondeau Formation comprises all lithologies of the basalt-andesite-dacite-rhyodacite-rhyolite ensemble. Both AFM and Harker variation diagrams show that all these rocks originated by differentiation from the same magma reservoir, and are related to one volcanic episode, This study did not, however, identify hydrothermal alteration zones useful for regional geochemical prospect ion.

Jan 1, 1984

By P. C. Garg

"IntroductionThe Central Mine Planning and Design Institute (CMPDI) of India, started planning the extraction of thick seams highly susceptible to heating in 1977by the French method of sub-level caving and/or multi-slicing. Nitrogen flushing was proposed for inhibition of heating by the author in one such project - the Kotadih colliery.Inhibition of heating was unheard of in the Indian coal industry before 1977-78. The usual practice was to seal off a district or a part of the mine or the entire mine when spontaneous heating occurred. With very little equipment in a normal bord and pillar district and a low production rate, the financial loss in capital assets and in production did not warrant any serious thought for inhibition of spontaneous combustion. With the planned advent of longwall mining, particularly sub-level caving, with heavy capital investment as well as high production potential, the sealing of a longwall face due to spontaneous heating could not be considered an appropriate solution.Principle of Inhibition of SpontaneousCombustionFrench engineers have established that a fire will not break out when oxygen is 15% or lower in the general body of the air. However, once a fire starts, the percentage of oxygen has to be reduced to 2% - 4% to extinguish it. It is this principle which has been used at Blanzy Coalfield in France to inhibit heating and it is claimed that this has retrieved the integral sub level method of mining. Nitrogen infusion has been used in Frence since 1978 to keep the oxygen content below 14% in the goaf."

Jan 1, 1987

By A. I. A. Salama, M. W. Mikhail

"The existing methods of block diagram manipulation and vanishing variable for flowsheet simplification used in coal and mineral processing circuit evaluation and optimization cannot be easily implemented on digital computer.The signal flowgraph technique is proposed to represent and simplify determination of the relationship between intermediate or end variable and the feed in the flowsheet. Typical and existing circuits are used to demonstrate the application of the proposed technique which can easily be implemented on digital computers.IntroductionRecently there has been much interest in the analysis and optimization of coal and mineral processing circuits to assist in the pre diction of coal and mineral processing plant performance. The block diagram and the vanishing variable were introduced and utilized in the analysis of plant flowsheet. Although the block diagram approach is useful, it requires manual manipulation of the circuit block diagram which may present difficulties in the situation of complex circuits. Moreover, it may not be easy to implement on a digital computer.In this paper, the signal flowgraph technique is proposed to represent the circuit flowsheet and to simplify the determination of relationships between intermediate or end variables (fractional mass) and the feed for any coal and for any mineral processing circuit comprising size and density separators. These relationships are utilized in the analysis and/or optimization of the circuit. The proposed technique is illustrated by considering typical and existing circuits."

Jan 1, 1987

By A. Gourlie

"This paper describes the performance properties of a new 95 ksi minimum yield strength, oil well casing grade designed specifically to resist hydrogen sulphide stress corrosion cracking, SSCc. The new grade, Soo-95SS, demonstrates NACE Tensile threshold values greater than 90% specified minimum yield strength, SMYS, and NACE Bent Beam values in excess of 12.7 x 1()4 psi. The new Soo-9588 grade also exhibits superior collapse and notch toughness values. IntroductionIn recent years, a trend toward casing grade specialization has resulted in the introduction of numerous proprietary grades designed specifically for particular production environments, In response, Algoma Steel has developed, as part of a "" grade for service"" philosophy, two new 95 ksi minimum yield grades. The two grades are Soo-95, High Collapse (HC), and Sour Service (SS). This paper describes the development of Soo-95 Sour Service.Four main objectives were established:1. Definition of the steelmaking and continuous cast processing practices2. Determination of the acceptable maximum and minimum levels for all chemical elements3. Definition of special processing requirements4. Definition of the physical characteristics and ranges of the product properties.This paper provides a description of the experimental approach, followed by a presentation and discussion of the trial results . Finally, a number of conclusions are given."

Jan 1, 1988

An essential tool for every step ? Early field survey ? Handheld satellite phones ? Portable satellite phones ? Exploration and Drilling ? Handheld satellite phones ? Portable satellite phones ? Production ? Handheld and portable ? Fixed Satellites systems ? Asset tracking systems Main applications via satellite ? Voice and Fax communication ? Internet access and E-mail ? Video conferencing ? Interconnection to mobile phones, 2 way radios, long range WIFI ? Equipment Tele-maintenance ? Telemedicine ? Crew and morale calling ? Vehicle and asset tracking

May 1, 2006

By T. Güyagüler, U. Y. Önder

"This study investigated the psychrometric properties of ventilating air in GAL coal mines. Related measurements were done in underground openings and have been arranged as input data for computer programs prepared for ventilation network and psychrometric analysis.Results obtained from network analysis have been used for psychrometric analysis of ventilating air. Changes in heat and moisture content of air in two major path s between entry and discharge of ventilating air have been investigated. Psychrometric processes occurring in the mine were determined and are shown graphically in Figures 1 and 2. Special attention has been given to determine the changes in psychrometric properties and processes involved in the faces. Results are outlined in this paper.IntroductionThe psychrometric properties of mine air are important factors to mine productivity and efficiency. Therefore, psychrometric analysis should be made for all underground mines; any undesired situation observe d could be corrected by taking the necessary precautions.The analyses were done as a case study for GAL mines, the only mechanized lignite coal mine in Turkey. In this mine, workable reserve is about 300 million tons of coal and yearly planned production is 2.2 million tons. Production is continuing from a coal measure-bed having two coal seams with average thicknesses of 1.52 m and 1.72 m respectively. A 0.85 m shale band exists between these two seams.Two full y-mechanized faces, approximately 220 m long, usually work simultaneously. All measurements, including mine gases and air velocity, are done by sensors connected to a control room by a monitoring system.In the analysis, a line diagram is utilized to described the mine on which every junction and branch is numbered."

Jan 1, 1992

By Karen Munro

Importance of Aquatic Studies for Mining ?Aquatic habitat is usually the first area where a mine interacts with the ?real world? outside the mine footprint ?Water management is a key consideration for a mine?Effects on the aquatic environment often extend to wildlife and human uses ?There is a lot of regulatory focus on issues of water quality, fish and fish habitat

May 1, 2011

By J. A. Eisele, D. L. Pool

"The Bureau of Mines has developed a particle agglomeration technique to improve the flow of leaching solution through heaps of low-grade gold-silver ores which contain clays. Benchscale experiments and industrial practice have shown that the percolation rate of cyanide leaching solution is greatly enhanced by mixing the ore with Portland cement as a binder, moistening the mixture, mechanically tumbling to form agglomerates, and aging before heap building and leaching. A slight modification ofthe technique allows its application to precious-metal-bearing tailings, which cannot normally be treated by heap leaching because they are too fine. IntroductionMany low-grade gold and silver deposits and tailing materials from former mining operations in the western United States are potential sources for precious metals. These sources are too low grade or too small to support the capital cost of a conventional cyanidation plant but have stimulated the development of lowcost procedures, such as extraction of the precious metals by heap leaching with cyanide. The Bureau of Mines has investigated methods to improve the recovery ofgold and silver by heap leaching these low-grade materials.For heap leaching to be successful, the crushed and stacked ore must have good permeability so that uniform distribution of the cyanide leaching solution through the heaps can be achieved. Some of the most difficult gold and silver ores to treat by heap leaching are those containing excessive amounts of clays, or fines generated during crushing. Excessive amounts of slimes, generally minus 50-micrometre or 270-mesh Tyler sieve size particles, in the heap feed will slow the percolation of the leaching solution, cause channelling, or produce dormant or unleached areas within the heap, resulting in long leaching periods and low extractions. In extreme cases, the clays or slimes can seal the heap and cause the leaching solution to run off the sides of the heap rather than through it."

Jan 1, 1987

By Ron Jessulat

"IntroductionBrunswick Mining and Smelting Corp. Ltd. is a IO 500 tid base metal producer. Development is carried out by Jarvis Clark MJM-21 3-boom development jumbos, using Tamrock E400, 410 and 550 pneumatic drills. Typical drift size is 13 ft by 18 ft with a 12-ft advance per round. Blast holes are 1 ½ in. in diameter while reamed holes are 3 in. in diameter. AN/FO is the principal blasting agent, being loaded by C-I-L model60R intermediate loader. The detonators are NONELS and DETINELS. Sulphide dust explosions occur during blasting when dusts from certain minerals such as pyrite and pyrrhotite are ignited by name from the detonating shots. The result is a secondary unwanted explosion with a characteristic shock wave and name front that are very destructive to mine services such as ventilation ducting, electrical cable, and ventilation control doors.A typical reaction in the Brunswick orebody occurs according to the chemical formula:4FeS 2 + IIOs-2Fe2O3 + 8SO2 + 3458--(Enright , 1988)The hematite (FeO3) is deposited as a red dust in the blast area while the toxic sulphur dioxide gas (S00 contaminates the underground workings . The presence of S02 gas disrupts production until it is purged from the area by the mine ventilation system or dissipates slowly in those areas where the vent ducting has been melted by the name front or torn down by the shock wave.Sulphide dust explosions exact a high economic toll. Direct costs in damaged materials and wages are probably exceeded by the value of lost production and disruption to the mining cycle. In addition, the health and safety concerns associated with sulphide dust explosions cannot be ignored."

Jan 1, 1993