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By Richard A. Allwes

A procedure is presented for the design of an arch canopy for the application of rehabilitating a high-roof-fall area. This procedure is specifically developed for evaluating an unbackfllled arch canopy, which Is subjected to an impact load (roof fall). Dynamic line loading of the arch canopy at its crown is only considered and the procedure does not account for an unsymmetrical loading condition. The evaluation of whether an arch canopy is suitable for a particular installation is dependent upon many variables, including in-nine conditions and the engineering properties of the structure. However, a general evaluation can be based upon a comparison of the arch's maximum crown deflection and a prescribed allowable crown deflection. A single spring-mass system is used as an idealized model to represent the dynamic behavior of the arch canopy at its crown. An energy approach is taken to determine the maximum crown deflection of an arch rather than solving a differential equation of notion derived from dynamic equilibrium. The design procedure is based on the concept that when an arch canopy is subjected to impact loading at its crown and deflects from its unloaded state to maximum crown deflection, the structure absorbs strain energy, both elastic and plastic. As a result, this strain energy can be calculated from a static load-displacement diagram for the structure. The significance of this design procedure Is that It gives mine personnel an analytical tool to select an arch canopy to meet the dimensional and functional requirements of a mine entry and a prescribed allowable crown deflection.

Jan 1, 1986

By Douglas Bartley, Kevin Hachmeister, Rich Barry

The use of explosive energy as a tool in mining and construction is the most effective way to move large amounts of rock that is otherwise unable to be efficiently excavated. Since the early days of explosive engineering utilizing black powder initiated by cap and fuse to the present day diversity of specialty products and technologies the goal has always been to "Break and Move" as much rock for the least expense possible. It has primarily been the competitive nature of our economy that has driven the advancement of technological innovations and practice. However, the concept of removing rock is not specific to the mining and construction industry. Since the dawn of creation, man has used rock as a medium to express his creativity in the form of sculpture. Even though the process of sculpture requires the removal of rock, the final work is defined by the rock that remains intact. This typically necessitates the extreme care of the sculptor to painstakingly chip away the rock allowing the image to emerge from the original mass of stone. The famous sculptor Michelangelo once said, "I saw an angel in the marble and carved until I set him free."

Jan 1, 2004

By Mario Samamé Boggio

El presente texto describe las condiciones en que se desarrollaba la industria extractiva antes de la dación del Código. Asimismo se revisa la política económica y social en sus aspectos económicos de la minería.

Nov 1, 1954

By Bo-Hyun Kim

Outline ? Strainburst criteria and hypotheses adapted for this study. ? Influence of excavation method on rock mass properties. ? Excavation disturbance factors vs. deformation modulus, etc. ? Estimation of blasting damage zone around excavation. ? Considerations of energy on burst-prone ground. ? Literature review & closed form solution. ? Numerical simulations. ? Summary and future works.

Oct 1, 2010

By J. W. Thompson

"The recent discovery and exploitation of petroleum territory have resulted in the enactment of new petroleum laws in most of the South American Republics. The activities in the discovery of these new fields were engendered by the knowledge of the fact that present producing fields must within well defined periods be exhausted. Oil operators were willing to take the initial steps in exploitation in the absence of legislation that applied strictly to petroleum operations. The enactment of modern legislation in many of these Republics encouraging and protect¬ing exploitations may cause tremendous oil activities in these countries, and the results may be comparable with the magnitude of the undertakings and the prestige of the companies now entering this territory.These, oil fields are admirably located for convenient distribution of petroleum by water to all the Nations using oil as fuel for shipping and industrial concerns. The oil markets of the western coast of South America will derive immense benefits from the Panama Canal. This navigation route brings these markets into direct ocean shipment with the Atlantic coasts of the Western and Eastern Hemispheres.One deterrent to oil production in the Republics of South America is the want of inland. transportation facilities, but the recent laws of these Republics without exception provide for acquiring rights of way for pipe lines and other modes of transportation; and doubtless the great interests and. syndicates already operating in these regions will, as production increases, provide ample pipe line transportation sufficient to convey to the coast the oil produced. It way be assumed, from the legal guarantees afforded, and from operating equipment and machinery that are now being concentrated that refineries will be erected at shipping points for the purpose of making these petroleum products accessible to the world."

May 1, 1921

By J. J. K. Daemen, C. Fairhurst

Introduction The stress field around a supported tunnel can be considered as being composed of: i) the virgin (pre-mining) stress in the rock ii) the (elastic) change in this stress field caused by creating the opening iii) the (time-dependent ) change in the stress field produced by (i) and (ii) as a section of the rock breaks up iv) the (time-dependent) influence of the stress build-up in the support. Several authors have examined the conditions necessary to produce static equilibrium between the support, the rock, and the regional (in-situ) stress field. The analysis used by Labasse (1) is typical. Consider a circular tunnel radius R in a hydrostatic stress field (P), and a radial pressure pi exerted by the support. According to Labasse, the radius ‘b’ to which the rock will break* for a given support pressure, pi, can be calculated from: - the equilibrium equation: [ ] As a zone of broken rock develops around the opening, the stress circle for a point on the elastic-broken rock boundary moves to the right in the Mohr diagram until the radial stress in the broken zone s equal to the radial stress in the elastic zone.

Jan 1, 1971

By F. Weinberg

"The recent development of the continuous casting process for steel has required basic understanding in a number of areas in the metallurgcal sciences. In some areas, information is still lacking. The success of the application of basic knowledge and research to the process is evidenced by the fact that a large percentage of the steel now produced in the world is produced by continuous casting.A number of areas in which metallurgical science has contributed and is currently contributing to better design and control of the continuous casting process and leading to a better quality product will be considered. These include:(a) heat transfer studies of the entire casting process;(b) fluid flow in the tundish, strand and liquid metal stream;(c) solidification structure and segregation;(d) strength and ductility of steel at high temperatures related to bulging and cracking; and(e) problems related to horizontal casting developments.IntroductionThe continuous casting of steel is a relatively new technology in steelmaking. It is now used extensively throughout the industry. In Japan, for example, continuous casting accounts for approximately 40010 of steel production, and this value is expected to increase to over 50% in the near future . New steel plants are now designed to use continuous casting exclusively. This means the process must work well and be completely reliable, because all the steel produced must go through the caster.The development of the continuous casting process in a short period of time has required concerted research and development in many areas . I shall cite a number of examples of these developments and refer to work done in Canada when applicable. No attempt will be made to review all of the research in continuous casting, nor refer to all of the workers in the field.The developments in continuous casting are based in many cases on metallurgical science, as described below. The use of metallurgical science in these developments is qualitative, in that concepts and idea s are used, as opposed to quantitative values calculated from fundamental equations. In general, most metallurgical problems are too complicated to enable fundamental equations to be used without the introduction of uncertain approximations and boundary conditions in the calculations.Starting at the beginning of the steelmaking process, very extensive research and development has been carried out to produce liquid steel of the required composition and temperature. The replacement of open hearth furnaces with BOF furnaces reduced refining time from many hours to roughly 30 minutes for 250 tons of steel. Two BOF furnaces effectively enable a continuous flow of steel to be available in a plant, essential for the introduction of the continuous casting process. This area of research will not be considered here."

Jan 1, 1981

By Ian Rozier

"Emphasis in recent years in western Canada has been placed on the development of large open-pit coal mines, the most notable developments being in northeast British Columbia. However, vast resources exist below the limit of economic open-pit mining, and with world demand predictions of the late seventies in mind, the potential of underground coal mining in western Canada has been investigated. Particular emphasis has been placed on the Plains coalfield of Alberta, and there is optimism that underground coal mines will be developed in the Lethbridge area of southern Alberta.With no existing operations in southern Alberta with which to compare mining conditions, any mine planning and feasibility level studies rely heavily on the engineering/geotechnical data obtained from surface investigation to predict ground control problems and technical constraints on mining. Such investigations have been integrated with exploration drilling programs. Emphasis has been placed on extracting maximum information to provide an over-all appreciation of potential ground conditions and to identify specific ground control problems that could be encountered.The acquired geotechnical parameters are then used to evaluate the mine properties from an engineering standpoint for input into the determination of optimum mine layouts, development directions, mining methods and roadway and face support requirements. These geotechnical studies have been primarily directed toward the longwall mining method, but the acquired data base could equally be applied to alternative mining methods.In addition to the lithologic and structural controls which relate to roof stability, caving characteristics, floor heave and subsidence, investigations have been directed at gaining an understanding of the over-all surface and ground water regime with respect to potential inflow into the mine openings and ground control problems that could be caused by inflows encountered during mining. Experience has shown that soft floor conditions and water control are important factors to be considered in a longwall layout, and without doubt these parameters will play a major role in the design and operation of a successful longwall operation in the Lethbridge coalfield."

Jan 1, 1986

By Clemens Catesby Jones

The substance of this paper, now amended and altered in form for its present use, was the basis of a private report prepared under professional engagement.* A private report is necessarily objective, and deprived of the scope and technicality of a scieintific treatise—which accounts for the prevalence of drawings and succinct mathematical statements rather than full descriptive details in a paper reproduced from data, of which all the original working-notes have been destroyed. In a practical sense the Hudson river valley clay-deposits owe their present existence to the protection afforded by the rock-formations on which they are supported, and, instead of being uniform in depth or continuity, are subject to the irregularities of the rugged masses which preceded and are now concealed by them. The only available information concerning these deposits contained in previous public reports or maps furnished at best a mere photograph of the surface, and as now apparent this was misleading or unreliable. It was the object of this investigation to determine in a practical manner the location, form and extent of all the clay-deposits at present existing in the lower Hudson river valley, and to ascertain with a

Jan 1, 1900

By Wright JK, Turner RE, Batterham RJ, Morrison AL

Simulation can play an important role in the design, optimization and control of complete industrial processes, the most appropriate method depending on the particular application. Most commonly, process models or simulators are means of representing the process which are either purely mathematical or physical. Mathematical models, however, almost invariably need to be based to some extent on experimental data or require experimental verification before they can be used with confidence. Ways in which experimental and mathematical modelling techniques can be combined to best effect are discussed, with reference to the simulation of iron ore induration and direct reduction processes. A novel method is presented for the simulation of direct reduction shaft furnaces. Small scale apparatus has been developed in which ore or pellet samples are subjected to the changing environment of the industrial process. The time dependent conditions (solid temperature and gas compositions) are provided by a mathematical representation of heat transfer and the conservation of mass and energy in the process Simulated.

Jan 1, 1986

By B OÆNeil

The Trent-Severn Waterway is a 386 km long navigation route through central Ontario between Lake Ontario and Georgian Bay, and is operated by the Parks Canada Agency. Its primary focus is to pass recreational boats through a system of 44 locks. The Big Chute Marine Railway (BCMR) is one site in the system that provides transportation for boats. The BCMR carriage is used to transport boats and their passengers on the inclined railway a distance of 230 m over a natural barrier from one body of water to another, with an elevation difference of 18 m. The unique feature of the haulage system used in this application is the variable angle of the incline from about 20 per cent rise changing to horizontal and followed by 20 per cent decline. In such conditions, unlike as in standard incline haulage, special configuration of hoists and drives is required. On the uphill part of the track, there is a need to have a motoring mode, on the downhill part a regenerating mode and on the horizontal part a combination of motoring and regeneration is required. The original system was built in 1978 and employed four 100 hp dc drive mine hoists to haul the 100 tonne conveyance loaded with 90 tonnes of boats. Due to failures and operational problems with the original system, in 1999 Parks Canada awarded a turnkey contract to ABB for a new, modern system of four single drum hoists. The new system was put into operation in 2000, only six months after receiving the order. The hoists are controlled by digital drives and a digital control system. Due to dramatic changes in the load conditions for individual hoists involved, the new system features many interesting solutions like changing drive modes from speed to torque control and a multiple, regulated braking system. It is a unique hoisting system, which could be also used in mining applications.

Jan 1, 2005

By D. R. Spink, G. L. Rempel, C. O. Gomez Bueno

"A morphological and chemical study of the Great Canadian Oil Sands Ltd. (GCOS) fly ash has been carried out. Extensive scanning electron microscopy, as well as light microscopy, showed that the GCOS fly ash consists of two fractions, one composed of unburnt or partially burnt irregular-shaped carbon particles and an ash fraction composed of transparent and opaque, often coloured, glassy spherical particles-some of them cenospheres (hollow spheres) and the others plerospheres (hollow spheres packed with smaller spheres). Microcrystals (0.1 to 0.3 um long) growing on the inner and outer surfaces of some of the spheres were also noted and found to contain more Fe, Ti, Ni and V than the spheres.The carbon-free GCOS fly ash particle size follows a lognormal distribution, with a geometric median particle size (by count) of3.8um and a geometric standard deviation of 1.84. IntroductionCanada's current energy situation strongly suggests that oil from the Alberta tar sands deposits will probably be recovered more extensively in the future. Today's commercially proven technology to recover oil from the Athabasca tar sands, as practised by Great Canadian Oil Sands Ltd. (GCOS), involves two major operations, namely: separation of the bitumen from the sand and upgrading of the bitumen to refinery oil; the production of significant amounts of petroleum coke and sulphur during the bitumen upgrading process. The bulk of the petroleum coke is burnt in boilers to fulfill the energy requirements of the entire operation. The boiler ash, which contains appreciable amounts of metals, such as vanadium, nickel, titanium, iron, aluminum and other elements, is collected in the boiler hoppers and cyclones of the petroleum coke-fired steam generation plants. Thus, as well as representing a petroleum resource, the tar sands represent a resource for vanadium and possibly other metals providing that metal recovery processes can be developed."

Jan 1, 1980

By Magdy Ibrahim

Detailed as-built project schedules are necessary to close out construction projects, benchmarking, forecasting, dispute resolution, and improving cost estimates of future projects. Manual procedures for developments of as-built documentation is time consuming, involves numerous interfaces and human interventions. This paper presents computational framework that encompasses automated site data acquisition and generates schedule updates utilizing commercially available project scheduling software. The work is carried out collaboratively with a Hydro Quebec team. The site data is captured employing mobile computing using iPad® type computers and Wi-Fi. The information is directly compiled in a centralized database server. The synchronization tool is a bi-directional application and is used on servers to communicate with iPad® computers deployed onsite. The captured data is stored in Microsoft SQL® relation database that consists of 63 entities. Computer software application has been developed in Microsoft Visual Basic® (vb.net) environment for extracting the collected site data, linking the database to the as planned schedule, and generating the actual, also known as as-built schedule. The development can be utilized in automated progress reporting, evaluating future bids, generating master schedules and a wide range of efficient EVM applications.

Aug 1, 2013

By C. E. Wethered

This paper describing the mining methods employed by the Federal Mining and Smelting Co., operating the Morning mine at Mullan, Idaho, is one of a series being prepared by the United States Bureau of Mines on mining practices, methods, and costs in the various mining districts of the United States. The daily tonnage produced at the Morning mine, including that mined by leasers, is 1,100 tons. Mine run of ore will average 9.1 per cent lead, 5.8 per cent zinc, and 4.4 ounces silver per ton. A stull set and fill method of mining is employed.

Jan 1, 1930

By D. E. Kirby

In the preparation of beryllium-copper alloys by fused-salt electrolysis, beryllium was electrowon from beryllium oxide dissolved in fluoride electrolytes and deposited on copper cathodes. At 880° to 1,030° C, deposition was on solid cathodes. Beryllium deposited on the copper, forming a liquid alloy that dripped from the cathode. Dripping alloys containing 3 to 4 weight-percent beryllium were produced with as high as 90 percent cathode current efficiency, by electrolysis at 910°.C. To prepare alloys of higher beryllium content, attempts were made at depositing beryllium on liquid copper cathodes. These efforts were generally unsuccessful, although alloys containing as much as 12 percent beryllium were prepared by this method. At temperatures of 1,100° to 1,300° C, requisite to maintaining beryllium-copper compositions as liquids, the beryllium reacted with cell structures.

Jan 1, 1972

By E. Chin

The mineral industry of Bangladesh was totally dominated by natural gas production and its downstream uses. A small amount of cement was produced, and clays were used locally for ceramics and construction materials. Nitrogenous fertilizer was produced from natural gas and a modest, scrap-based steel industry produced steel for local consumption. The country has been developing and using its abundant and inexpensive gas reserves as fast as practical. The population, however, was predominantly dependent on agriculture for its livelihood. The industrial sector accounted for 10% of the economy, and most of the industrial output was directly associated with agricultural products jute, tobacco, and textiles. Industrial expansion, even with the availability of gas, was severely constrained because of limited domestic demand, lack of skilled work force and management, poor infrastructure, and a low rate of domestic savings. To put greater emphasis on the industrial sector, the Government established a National Committee for Industrial Development in July. The Committee instituted policy reforms in the areas of trade and investment. One important step was to move from a positive import list to a negative list, thereby permitting imports of items not restricted or banned. The system for recovering and approving new domestic or foreign industrial investments was streamlined to expedite what had become a cumbersome, bureaucratic exercise. To encourage industrial development in areas away from the crowded urban centers, several economic incentives reportedly were adopted. These included a reduced tax rate on imported machinery, exemption of import license fees, a reasonable debt equity rate, and a 9-year income tax exemption period.2 In the trade sector, imports increased 12% in fiscal year (FY) 19843 mainly

Jan 1, 1987

By John R. Bartels, Dean H. Ambrose, Richard C. Wang

This paper presents the results of a study to verify and validate a computer model that represents and analyzes motions and hazardous events in a simulated three dimensional workplace. The purpose of the computer model is to support research that is investigating the safe speed range for the vertical movement of roof bolter boom arms to reduce worker injuries in underground coal mines. The information obtained for this paper is based upon a project that is investigating means to reduce workers risks of injury from exposure to mining machinery. The methodology being employed by the project includes human factors design considerations, anthropometric modeling and simulation tools, laboratory validation, engineering interventions, and collaboration with industry and an equipment manufacturer. The results of this study were used to (1) determine the input parameters that are unique to the mining environment and needed to develop a credible, computer-based, human-machine interactive model, (2) develop test methods to measure the required parameters, and (3) to refine the human-machine interactive computer model.

By T. P. Kostek

"Historically, gear pumps and motors have been popular in the mining industry because of their competitive cost, simple yet rugged construction, ease of rebuild, and relative long life and insensitivity to contamination. However, with the ever increasing ""popularity"" of fire-resistant hydraulic fluids, both users and manufacturers of gear equipment must make special considerations to enable the equipment to continue giving satisfactory performance even with the water-containing fluids.The paper discusses 60-40 invert emulsions and waterglycolsIntroductionMuch information has been published on the specific characteristics of the various types of fire-resistant hydraulic fluids. Fluid manufacturers' literature and other publications have dealt with such specifics as fire resistivity, seal compatibility and wear rate characteristics. Gear pumps and motors have been, and will continue to be, applied successfully in hydraulic systems employing both the ""invert"" emulsions (60-40) and water-glycols as the hydraulic fluid.Because most external spur gear equipment has been designed to function with petroleum oil as the fluid medium, certain guidelines must be followed to ensure satisfactory service life. FluidsThere are a number of different types of fluids which fall in the category of"" fire-resistant"" , the most common'being phosphate esters, water-in-oil emulsions, oil-in-water emulsions and water-glycols. The two in most prevalent use today as hydraulic fluids are the water-in-oil emulsions and the water glycols"

Jan 1, 1980

By Christopher Mark

The past decade has provided a wealth of practical experience with longwall pillar design. Design formulas developed specifically for longwalls have proven their value in numerous applications. Analytic methods, including numerical models, have a1 so made important contributions. These advances have been based on basic research into abutment loads, coal pillar mechanics, and the interaction between pillar performance and entry stability. The goal of this paper is to review the state of the art in longwall pillar design from the standpoint of the practitioner. Actual case histories are presented to illustrate the current capabilities and limitations of pillar design methods. The paper also discusses the advances that can be expected in the future.

Jan 1, 1990

By W. J. Loring

It is proposed to describe in this paper as accurately as possible the present practice at the Utica mills, of which I am superintendent. The Utica Company operates three mills, the Madison (40 stamps), the Utica (60 stamps), and the Stickle (60 stamps). My description will be based on the last-named, in which I have experimented more than in either of the other two; but the practice is the same, under the same management, in all three. Everything is run by water-power, under about 420 feet fall at the Utica mill, and 425 feet at the Stickle mill, giving a pressure of about 185 pounds to the square inch. The Madison mill is situated about three-quarters of a mile below the Utica and Stickle mills, and has only some 100 feet fall from one place, and 38 feet fall from the other. The water that runs the Utica and Stickle mills, and all machinery connected with the corresponding mines, is conveyed through ditch and pipe to the Madison mine and mill, where it develops power for the air-compressor and the 40-stamp mill. The mill is run by a

Jan 1, 1899