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By R. E. Johnson

Seventy years after the start of the Industrial Revolution in Great Britain, as reckoned from Arkwright's water frame patented in 1769, there was a significant development of the metallurgical industry in Virginia. In Britain, crucible steel had been rediscovered by Benjamin Huntsman in 17~0, and this made spring and tool steel more generally available. The metal-turning, screw-cutting lathe, including the basic principles recognized in today's engine lathe, was developed by Henry Maudslay about 1797. Wrought iron, as manufactured by Henry Cort's process patented in 1784, was readily available. Richard Trevithick's highpressure steam locomotive had met its test on the Pennydarren tramroad in 1804, and George Stephenson had built his famous Rocket, along with several other locomotives, at Newcastle around 1828. Puddling furnaces and a rolling mill had been placed in operation at the Tredegar Iron Works in Glyn Sirhowy, Monmouthshire, Wales, in 1807. In the United States, expanding commerce and a growing population resulted in continuing development from the Chesapeake to Virginia's Blue Ridge, and this demanded improved means of transportation. Ore deposits rich in hematite had been found in Virginia's Piedmont during the Colonial period, and a number of blast furnaces now dotted that area. The products of these operations were mostly pots, kettles, stove parts and like items for local trade. The James River and Kanawha Canal was incorporated in January 1785. Its eastern leg, winding along the slope of the high bluffs overlooking the river, was completed about 1800. About two dozen railroads were chartered in Virginia between 1830 and 1837. With expanding population and steady industrial development came a need for metallurgical products. Throughout the eastern United States, numerous metallurgical enterprises sprang up, and many of these flourished. The purpose of this article is to outline the development of one Southern metallurgical company, the Tredegar Iron Works, which was to have a significant impact on the industrial development of Virginia and the fighting of the American Civil War. Although the Tredegar Iron Works no longer exists, remnants of the early operations have been restored, and the current status of the site is also presented.

Jan 1, 1999

This work illustrates the potential of two welding processes for joining AA1100-16 vol.% B4C metal matrix composite: laser welding process using a 4 kW Nd:YAG laser and Friction Stir Welding. A comparison is made between these two welding techniques in terms of microstructure and mechanical properties of welded joints. A large amount of brittle needle-like phases, together with some residues of B4C particles were observed in the fusion zone of laser welded joints. The use of Ti filler can improve the microstructure and increase the joint efficiency from 63% to 75%. On the other hand, the friction stir welding process being a solid state welding technique is interesting as it avoids the formation of brittle intermetallic phases. In addition, the breakage of B4C particles and the grain refinement of the matrix were observed in the weld zone. Consequently, FSW joints show much better mechanical properties than laser welded joints. Up to 100% joint efficiency can be achieved by FSW for annealed AA1100-16 vol.% B4C materials.

Jan 1, 2011

By I. C. Edwards, E. O. Lilge, H. H. Mccreedy

"Introductory and GeneralTHE DRIESSEN CONE bas been used fairly extensively commercially as a classifier. Its use as a concentrator in the upgrading of ores at a fairly high ratio of concentration with concomitant recoveries has been almost negligible. Certain known features about the cone, however, such as its high throughput capacity, cheapness of construction and operation, and simplicity of design have attracted the attention of mill men. An inadequate knowledge of the operating characteristics of the cone when used as a concentrator seems to have been the main reason for its lack of use. It was for this reason that the present investigations§ were undertaken to determine the operating characteristics of the cone and its application to the concentration of uranium ores, with particular emphasis being placed on the concentration of low-grade uranium ores.The investigations were started in December, 1951, and have continued uninterrupted to the present. The initial work was confined chiefly to investigating the operating characteristics of the cone in order to establish the trends that certain variables would exert on the general metallurgy of uranium concentration. Optimum metallurgy was therefore not the prime initial objective."

Jan 1, 1955

By D. W. Duncan, A. Bruynesteyn

Acidic mine waters containing solubilized uranium have been observed in many uranium and some copper mines. In every case, the sulphide and iron oxidizing bacterium, Thiobacillus ferrooxidans, was also present. This bacterium provides the ferric iron required to oxidize u+4, both by oxidizing available ferrous iron and by oxidizing pyrite or other available sulphide minerals. This latter oxidation also provides sulphuric acid and may increase extraction by exposing more uranium. The enhancement of bacterial activity and the results of some field tests are discussed.

Jan 1, 1971

By J. Basi, D. F. Rucker

"A review of historic operating practices of the heap leach pads at the Los Filos Mine, Mexico, revealed periods of restricted cyanide addition, reduced leach time, and insufficient irrigation flow. These issues all led to the buildup of partially leached recoverable gold inventory within the leach pads. Drawing down this inventory represented an opportunity to bring value forward. This paper outlines the strategic initiatives which were implemented as efforts to accelerate the inventory drawdown, including geophysical mapping and pressure injection.INTRODUCTION Los Filos is a heap-leach operation located in the Guerrero gold belt in southern Mexico. Operational and hydraulic challenges at the Los Filos Mine have led to a buildup of gold in inventory within the leach pads. Operationally, periods of restricted reagent addition, reduced leach time, and insufficient irrigation flow have compounded over the last eight years, and resulted in significant inventory growth. Hydraulically, the leach pad has issues with low permeability and solution channeling due to the fines and clay content of the ore. The leach pad is storing high-grade pregnant leach solution (PLS) as perched aquifers above areas that are compacted and difficult to drain. These operational and hydraulic challenges made it particularly difficult to spatially predict the precise locations of the inventory build-up. Fortunately, the challenges at Los Filos are not unique to the mine, and others have taken steps elsewhere to reduce metal inventory through a program that targets areas for inventory drawdown. For example, Ghorbani et al. (2016) noted that a method of injecting barren reagent solutions, applied directly to specific areas of a leach pad to reduce inventory, was presented by Wan and Brierley (1997) and Wan (1997). Seal (2004; 2007), Seal and Jung (2005), and Seal et al. (2012) have put the injection methodology into practice in Nevada and Colorado gold mines with a technology called Hydro-Jex®. The goal of Hydro-Jex has been to supply reagents at a high pressure over a short duration, followed by periodical low pressure rinse periods to remove leached metal and resupply fresh reagent to the ore."

Jan 1, 2017

By O. Hall

STOPING at Noranda" is a sequel to "Mining at Noranda". "Mining at Noranda", presented in 1937 (1), sketches Noranda's history, metallurgical problems, exploration, mining methods, mining details, pillar extraction, and costs. "Stoping at Noranda" deals in greater detail with our stoping, the use of sub-level drifts instead of benches, and the drilling out of the stopes with jointed rock drill steel and diamond drills. Sun-LEVEL DRIFT STOPING: Sub-level drift stoping is almost universal throughout the mine and is the standard sroping method in both sulphide ore and rhyolite flux ore. The features that have led to the adoption of this standard are: (1) Continuous symmetrical drilling in sub-level drifts with no delay for blasting. (2) Large-tonnage blasts Saturday night after the drillers have left. (3) Comparative freedom from gas and smoke during the working days. ( 4) The daily safety achieved by having all stope drilling done in drifts. (5) The safety and security achieved by drilling out stopes, floors, and pillars before there is any weighting or cracking.

Jan 1, 1939

By Lang Tao, Jun Wang, Wei Xiao, Wenqing Qin, Pan Cao, Guanzhou Qiu, Key Lab of Biohydrometallurgy of Ministry of Education, Central South University

"The effect of metal cations on the rutile flotation using styryl phosphoric acid (SPA) as the collector was investigated by micro-flotation test, bench scale flotation test, zeta-potential measurements and adsorption measurements. The micro-flotation results indicated that Fe (?) and Al (?) ions in low concentrations had obvious activation on the rutile flotation, and Pb (?) ions in low concentrations had smaller activation of rutile, but Fe (?), Al (?), Pb (?), Ca (?) and Mg (?) have strong inhibition of rutile flotation in high concentrations. The bench scale flotation results indicated ethylene diamine tetraacetic acid (EDTA), boracic acid, and sodium hexametaphospate can decrease the metal ions concentrations, and increase the recovery of rutile flotation. Adsorption measurements and zeta-potential measurements revealed that Fe (?), Al (?) and Pb (?) ions were adsorbed on the rutile surface, and had interaction with SPA. But when these ions concentration were over the largest adsorption capacity, residual metal ions could occur chemical reaction with SPA.INTRODUCTIONRutile is one of the favored minerals for production of titanium dioxide white pigment, primarily through the chloride manufacturing process (Stanaway 1994; Hou et al., 2013) However, the majority of rutile ores belong to refractory ores, while flotation is one of the most efficient methods to separate fine rutile from gangue (Dolbear et al., 1937). With the flotation development, many effective collectors were successfully applied in the oxide ore. Many reviews have indicated that organic phosphonic acid collectors showed good selectivity on oxide ores such as ilmenite and rutile (Bulatovic & Wyslouzil 1999; Liu & Peng 1999).It is inevitable that many types of metal cations are present in ore pulp. These metal cations significantly influence the flotation of minerals. Liu et al. (2015) showed that Ca2+ and Mg2+ could improve the floatability of spodumene at pH 12.5 and 10.0, respectively. The authors proposed that Ca2+ and Mg2+ ions readily form hydroxy complexes (CaOH(l) and MgOH(l)) and precipitates as (Ca(OH)2 and Mg(OH)2) in strongly alkaline solutions. Fan and Rowson (2000) investigated the effect of Pb(NO3)2 addition as an activator on ilmenite flotation and showed that it could improve ilmenite floatability. The addition of Pb(NO3)2 resulted in an increase of ilmenite zeta potential in both weakly alkaline and acidic aqueous solutions. Mehdilo, Irannajad, and Rezai (2015) studied three kinds of ilmenite of different origins and discovered that both Mg and V had a negative correlation with ilmenite flotation, while the Mn content seemed to correlate positively with flotation efficiency. A number of studies have also showed that Fe3+ can improve the floatability of ilmenite (Fan et al., 2009; Nuri, Mehdilo, & Irannajad, 2014)."

Jan 1, 2016

By J. F. Davis

Pegmatite dykes containing lithium minerals and beryl occur dose to the borders of intrusive masses of granitic rock in the Winnipeg River area of Manitoba. Both vertical and flat-lying dykes are present. Most of the pegmatites consist of zones, containing characteristic mineral assemblages, arranged more or Jess parallel to the borders of the dykes. Five important lithium minerals are present; each occurs in a separate zone, but all the lithium-bearing zones are situated toward the centres of the pegmatites. Spodumene is the most abundant and widespread of the lithium minerals and occurs as small crystals intimately intergrown with quartz. Beryl is not an important constituent of the lithium pegmatites, but when .present, occurs outside the lithium zones, toward the margins of the -dykes. Beryl is most common in dykes containing few or no lithium minerals. The mineral assemblage in the beryl zone of the lithium dykes is the same as that of the beryl dykes. The attitude and internal structure, particularly zoning, of the pegmatite dykes, and the texture and assemblages of the constituent minerals, have an important bearing on exploration, development, and mining of these pegmatites, and on the extraction of various mineral products from them.

Jan 1, 1958

By E. Nolasco, J. Ouellet, T. Tikka

"Shaft bottom structural systems are used in underground mining to support transfer of personnel, equipment and ore to and from underground to the surface. This paper first summarizes the evolution of design philosophy from a concrete tower supported on a concrete plug to the current structural steel design arrangement with unlined shaft walls, clear shaft bottom area with only a concrete housekeeping pad. Then the paper reviews the design parameters, analysis and design, and construction methodology for this rather unique shaft bottom structural system consisting of three sets of hitch beams, with each having specific functional requirements. INTRODUCTION Shaft bottom structural systems are used throughout the world in underground mining operations to provide a means to support the transfer of personnel, equipment, materials, ore and waste entering and exiting a vertical shaft ready for transport to and from the surface via the hoisting system. The shaft bottom structural system, for the Service Shaft (SS) at the Jansen Mine, is designed to accommodate two skips, a personnel/equipment cage, counterweight, services, loading pocket, rope changing, arrestor system, crash (or catch) beams, access platforms, stairs and rope divider system. Stantec and BHP have engineered a unique structural steel shaft bottom system for hoisting system at a Potash Mine. The shaft bottom structural system connects to a fixed guide and cantilever bunton system, used in the vertical shaft (shaft barrel), above the shaft bottom. The geometry for the shaft bottom structural system, shown in Figure 1 a), features three sets of hitch beams, beams which span across the shaft excavation or barrel. At the top of the structural system are two upper hitch beams. These hitch beams support a 64 metre suspended rectangular braced tower (upper tower), complete with steel guides for the conveyances. The upper tower passes through the main station (potash or mining) level and then connects to the top of the arrestor (lower) tower structure via a sliding vertical connection. The potash level is supported by two hitch beams spanning the shaft and loading pocket excavations. The arrestor tower, a braced compression tower structure, is carried by a third set of hitch beams. Below the third set of hitch beams is a short suspended tower complete with access platforms, stairs and the rope divider system."

Jan 1, 2019

By B. Damjanac, S. Maxwell, D. Chorney, M. Grob, F. Zhang, J. Hazzard

"A hybrid discrete-continuum numerical scheme is developed to study the behavior of hydraulic fractures crossing natural fractures. The fully coupled hybrid scheme utilizes a discrete element model for a core domain, within which the hydraulic fracture propagates and interacts with natural fractures, and a surrounding continuum domain to better approximate boundary effects. The results show that the behavior of hydraulic fractures crossing natural fractures is affected by a combination of factors. Nevertheless, three fundamental crossing scenarios can be identified from all of the simulations: no crossing, partial crossing, and direct crossing. Each crossing scenario has a distinct injection pressure history which may suggest guidelines for interpreting field hydraulic fracture injection data. Additionally, the capability for these models to generate synthetic microseismicity makes them appealing for the integration of microseismic field data with the reservoir geomechanics for ultimately providing a practical engineering tool for improvement of well completion and stimulation. The model is capable of examining and verifying four different shear deformation mechanisms associated with a propagating hydraulic fracture. The natural fracture can fail solely due to the stress perturbation of the passing hydraulic fracture or it can fail due to a combination of stress and pore pressure changes across different types of interaction scenarios. The simulations also illustrate that the level of fracturing complexity increases as the number and extent of the natural fractures increase. INTRODUCTIONAlthough hydraulic fracturing technique has been applied extensively as a reservoir stimulation technique in the oil and gas industry for over 60 years (Economides & Nolte, 2000), it is one of the key factors promoting the shale gas boom in the past decade (King, 2010; International Energy Agency, 2014). The hydraulic fracturing of shales can be differentiated from hydraulic fracturing of conventional reservoirs by the fact that shale formations often have a pre-existing discrete fracture networks which greatly impact the hydraulic fracture propagation. Based upon field production data as well as microseismic observations, it is believed that so called “fracture complexity” may result from interactions between a created hydraulic fracture and pre-existing natural fractures and planes of weakness (Warpinski, 2009; Maxwell & Cipolla, 2011)."

Jan 1, 2015

By J. Gordon Parr, D. A. Whitaker, G. A. Yorko

High purity alloys of zinc with 25 per cent to 50 per cent aluminum, have been prepared. Mechanical properties of the as-cast and heat-treated alloys have been related to constitution, determined by x-ray diffraction and microscopic methods. Investigations include the effects of aging and of small nickel additions on the properties of the alloys.

Jan 1, 1960

By C. Karpuz, Y. S. Istanbulluoglu

This paper describes the results of convergence measurements conducted about five years for the re-use gate roadways at OAL lignite mine in Turkey. Double lignite seams separated with a marn layer, are mined with long-wall retreating mining system at the mine. Rib pillar has been abandoned and gate roadways were planned to be packed for the re-use of full extraction. Various packing systems have been attempted, namely three rows of woodenchock, one row of wooden chock plus concrete wall and concrete wall only. The re-use of maingate roadways packed with wooden chock yielded 62% of closure. Lastly developed concrete packing of 3 meters wide and specially developed support set composed of three friction props and a cap, which is a modification of yieldable set, have successfully maintained the main and tail gate roadways stability with a total vertical convergence of 32%. Good correlation has been established between pack stiffness and floor heave as well as maingate and tailgate convergences. The elimination of rib pillars by re-use of gate roadways increased the coal recovery by 20% and decreased the development/production ratio from 0.065 m3/ton to0.022 m3/ton.

Jan 1, 1997

By Seong-Taek Lim

Recently, 7xxx aluminum alloys have been evolved into new variants for thick semiproducts which have low amount of 2nd phases and low quench sensitivity. Commercial 7xxx alloys, especially in the thick forgings made of big ingots, often entail microstructural inhomogeneities and concurrent poor mechanical properties due to limited heating ranges and slower quench cooling. In this study, high strength aluminum alloy 7175 and 7050 are adjusted as an attempt to control the equilibrium phases (M-, T- and S-phase) to have optimum microstructure for the thick forging applications. The effects of the relative content of (Zn, Mg, Cu) on the evolutions of the coarse equilibrium phases, hardening response and resultant mechanical properties are investigated. Equilibrium phases (M,T,S) are evolved depending on the constitutional effect, primarily the change of Zn:Mg ratio, and cooling rate following solutionizing. The formation of the T- and S-phases is effectively controlled, and M-phases are homogeneously precipitated in the adjusted (dilute and high Zn:Mg ratio) alloys. It provides extended heating range and lower quench sensitivity than conventional alloys. The attempts ensure the microstructural homogeneity and improved properties, and is expected to be uniquely applicable in 7xxx thick forgings.

Jan 1, 2004

By John B. Phillips

The mine is entered by a central vertical shaft, strongly timbered, and containing two compartments-one for the passenger cage, the other for the large skips bringing the ore to the surface. A man-way, for emergencies, is also provided, parallel to the shaft. The cage is a single-deck steel box, carrying about thirty persons; by means of arrangements above and below, it can also hoist and lower materials needed in the workings. Levels are run at intervals of 100 feet. In special cases, where the ore conditions warrant, sub-levels are operated, such as those at 1,113 feet and 1,123 feet (Fig. 7), which are connected by winzes with the 11 th level. One of these was pushed for 40 feet, and then abandoned because it was unprofitable to take up ore of the grade encountered. The ore between levels is removed by stoping. The drifts follow the course of the veins as much as possible, with numerous cross-cuts. Winzes, raises, connections, etc., are blasted out where needed. The main drifts are at least 8 ft. high by about 9 ft. wide. All former narrow drifts had to be widened some time ago, by ruling of the Ontario Department of Mines, to lessen the danger of accidents with cars in the small passages. Accurate plans of the under-ground workings are kept in the office, and extensive surveying is always being done underground to keep the maps up to date, measure the cubical contents of stopes, and so forth. Timber is extensively used in the construction of supports and chutes, and in the sinking of the shaft. Steel and concrete are too ex pensive to compete with timber, which 1s abundant in such sections as have escaped forest tires.

Jan 1, 1926

By Sanat Talmaki

Construction and mining worksites pose unique challenges to workers and equipment operators due to their dynamic and unstructured nature. Narrow haul roads, crowded work spaces and presence of workers and equipment in close proximity, combined with large blind spots and overall poor visibility afforded to operators lead to collisions and run-over-type accidents between equipment, workers, and other entities that may be present on the jobsite. Operations that involve machine-infrastructure interaction, particularly in the case of concealed infrastructure such as excavation and drilling lead to unintended strikes between the equipment?s end-effect or and the infrastructure. Such accident-prone scenarios can be avoided by providing operators with real-time feedback and warnings using 3D visualization and proximity monitoring of the entities present in the equipment?s vicinity. Thus the jobsite in the real world is abstracted and represented in a 3D virtual world. However, this requires the ability to create a seamless link between real-world sensors present on the equipment and/or the jobsite and the virtual environment. This paper describes a non-restrictive acquisition allocation framework that allows position and orientation sensor streams from construction and mining job sites to be used for updating 3D virtual scenes in real-time for providing vital collision avoidance warnings to equipment operators.

Aug 1, 2013

By G. L. Palmer

"Abstract- ln 1986, anomalous sampling results for heavy minerals were obtained at various sites in Namaqualand on the west coast of the Cape Province. Drilling in 1987 at Graauwduinen penetrated up to 35 meters of heavy mineral-bearing Tertiary sands which extend several kilometers inland from the coast. The heavy mineral suite includes ilmenite, rutile, leucoxene, zircon and monazite, along with garnet, pyroxene and amphibole. Three deposits are recognized, two of which comprise the resource to be mined by Namakwa Sands Limited, a recently formed Anglo American Corporation subsidiary company.Mineable reserves in excess of 500 million tonnes have been delineated, sufficient to sustain mining for over 35 years at projected production rates. During the feasibility study, on-site investigations included test mining at various sites to assess mineability and to provide material for metallurgical testing in a pilot plant located at the site. Ilmenite produced at the mine will be smelted at a new facility to be built at Saldanha Bay . Saleable products comprise titania-rich slag, pig iron, zircon and rutile.During the exploration phase, company environmental guidelines were established and monitored. The feasibility study incorporated a Class 1 Environmental Impact Report, the contents of which were made public following the principles of the Integrated Environmental Management legislation."

Jan 1, 1994

By D. M. Ziebarth

"Normal sequence of operations to develop a new underground mine is: construct and outfit headframe for shaft sinking, sink shaft, construct and outfit shaft sump, develop shaft station and shaft bottom steel. In an effort to reduce the overall project schedule, an innovative plan was developed to install service shaft steel below station level, prior to the completion of the shaft sinking effort. To better evaluate the construction of this substantial steel tower, a preliminary constructability evaluation was conducted, including the best method of supporting the main tower; from the bottom, middle or top of the tower. The design criteria and plan involved: •,Develop access from existing service shaft, 25 km underground •,Use of materials to maximize strength while minimizing corrosion exposure •,Estimating the location of the shaft centerline •,Over excavating the station and shaft below station to allow future shaft steel repositioning •,Designing the tower steel for modular installation •,Incorporate commissioning considerations, such as suspension of the cheese weights during steel installation •,Provision for covered stair access to shaft bottom •,Enclosed shaft envelope with open panels to allow visibility and ventilation The design approach was innovative and this paper will describe the design principles and challenges encountered while providing insight into the solutions developed and implemented; especially the modular construction and installation methodology. INTRODUCTION In an effort to expand the mining operations, a plan was developed to construct a new service shaft closer to the new mine workings and convert the existing service shaft to a production shaft at the Potash Corporation of Saskatchewan Inc. (PCS now Nutrien) Rocanville Potash mine in southeast Saskatchewan. The new service shaft required a multi roped friction hoist operating a cage / counterweight, rope guided conveyances to support the operational requirements. The service shaft is an integral part of the mining infrastructure as it provides access to the underground workings, transport personnel and materials underground for operation and maintenance of the mine. The shaft also allows for services required for safe operation of the underground mine, power supply, controls, communication, dewatering and fresh water supply."

Jan 1, 2019

By M. Bustin, A. Hosseinian, G. Preisig

Hydraulic fracturing and hydraulic shearing techniques are essential for the development of unconventional oil & gas and geothermal resources. Such techniques will also play a key role in the development of CO2 sequestration, and management of high stresses encountered with deep mining. However, the optimal design of hydraulic injections is often limited by continuum treatments of the rock mass without consideration of the influence of the natural fractures present. These may interact with the hydraulic fracture to promote offsets or arrest, or may cause the natural fractures to undergo shear and dilation. Given the limited access to the rock afforded by deep boreholes common to oil & gas and geothermal projects, advanced numerical modeling is critical for understanding key mechanisms and interactions. In this work, we first present a coupled hydromechanical distinct-element model focusing on the propagation of a hydraulic fracture. Normal and shear displacements arising from the generated hydraulic fractures are subsequently integrated into a fracture flow model for detailed analysis of specific flow behaviour and fracture permeability. For this, a scanned 3-D profile of a natural fracture is used to correlate surface roughness to dilation as a function of shearing. Fracture flow is computed at different time steps corresponding to different fracture propagation states and geometries. Modeling results indicate that the opening of a tensile hydraulic fracture is accompanied by millimetre-scale shear displacements associated with slip and wedging between adjacent blocks. This may leads to a mismatch between the upper and lower walls of the fracture if asperities are irregular and strong enough. However, fluid-induced tensile fractures have low Joint Roughness Coefficients (JRC), and associated millimetre-scale shear displacements are too small to ensure a significant offset of asperities that prevent a fully-elastic closure when the hydraulic fracture is depressurized. Injection of proppant is thus critical to keeping hydraulic fracture apertures open. Future work is planned that will see the models calibrated against field data including microseismic event locations, magnitudes and source mechanisms, tiltmeter deformations, stress change, and pore pressures.

Jan 1, 2015

By M. Fafard, M. Dupuis, P. Goulet, J. Bédard

Start-up of a Hall-Heroult cell is a delicate task that can affect pot performance and pot life. Modem practices for high amperage cells involve preheating the lining before the molten electrolyte is poured in. Different preheating methods and heat-up schedules are used throughout the industry, and the optimum between a short start-up and damage minimization to the cell is elusive. Direct electrical coke-bed preheating is one of the most common techniques. This practice typically results in a non-uniform surface temperature distribution and can generate detrimental thermal gradients in the cathode blocks. Numerical modeling is an invaluable tool to study this complex problem and can help improve the preheating procedures. The modeling of the mechanical response of the lining is critical to detect risks of cathode block cracking or the development of gaps where liquids could leak into. Taking into account the baking of ramming paste, the quasi-brittle nature of carbon and the contact interfaces between different materials are examples of key elements to consider. A finite element slice model of a cell was built and simulations of different electrical preheating scenarios were performed using the inhouse code FESh++ to demonstrate what can be learned through thermo-chemomechanical modeling. The potential industrial application of the model is discussed.

Jan 1, 2006

By R. C. Rowe

THIS paper is an endeavour to analyse the ideal and practical functions of government technical mining services, and their relationship to the National Domain, as well as to one another. its spirit is not critical, even though at times it may appear to besoin fact. It is a serious effort to divert a trend in public thought which delights in calling itself practical whereas it is really merely short-sighted. The author refers particularly to the idea that governmental research is a luxury which should be curtailed in the interests of economy, and turned over to private enterprise or the provinces. In order that we obtain the proper perspective of the question, it is advisable to indulge in a little history. In the year 1842, the Geological Survey of Canada was formed under the guidance of William (later Sir William) Edmund Logan. The literature on the founding and history of the Geological Survey of Canada is extensive, and therefore it is unnecessary to go into detail here regarding it. It might be mentioned, however, that the Geological Survey of Canada is only seven years younger than the Geological Survey of Great Britain (founded in 1835), and is only exceeded in age on the American continent by the State Geological Surveys of New York, Pennsylvania, Massachusetts, and Michigan, which were founded between 1833 and 1836. In 1877, the Geological Survey became a permanent government institution as a branch of the Department of the Interior. It should be noted, however, that the Director of the Survey ranked as a Deputy Minister and reported direct to the Minister. This continued until 1907. In 1886, the Mineral Resources and Statistics Division of the Geological Survey was formed. Some years later, the Canadian Institute of Mining and Metallurgy (then the Canadian Mining Institute), backed by the mining press, began to agitate for the establishment of a Dominion Department of Mines, and in 1907 such a department was founded by the Geology and Mines Act of that year, with a separate Cabinet portfolio for the position of Minister of Mines.

Jan 1, 1939