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By Kevin Phelps, Jason Baird

When dealing with high velocity projectiles, the ability for researchers to accurately and precisely measure the velocity of the projectile is of great value. This report will analyze three different methods of recording high velocity projectiles for: their ability to record velocity data, pros and cons for each method, and any possible bias or limitations that would result. Method 1 uses a Phantom V10 high-speed video camera and a velocity reference screen to record the projectile’s path and proprietary Phantom software to analyze the data and determine velocity. Method 2 utilizes two break screens. This method, consisting of strung copper wire as the break material, is one that has been used in the past by Missouri University of Science and Technology (MS&T) researchers in assisting in finding velocities of high-speed projectiles. Method 3 is a pair of make screens, similar to Method 2 in that two screens were used for each test but relies on a projectile making a circuit between two sheets of metal separated by an insulation layer, to find a velocity. All three methods will be used simultaneously in each shot to rule out any projectile differences in subsequent shots. Projectiles of three different relative velocities, low, medium, and high, will be fired and analyzed to determine strengths and weaknesses of each method.

Jan 1, 2014

By G. R. Fitterer, E. A. Krockenberger, B. E. Sockman, R. B. Meneilly, J. F. Eckel, E. W. Marshall

"Steel manufacturers have noticed a decided tendency on the part of many of their customers to become more exacting in their steel specifications. Under these conditions, the steel must not only meet the specifications of physical properties (tensile strength, reduction of area, elongation, impact strength, grain size, normality, etc.) and the chemical analyses, but must also pass the inspection test of ""cleanliness.""By cleanliness is commonly meant the absence of oxide and sulphide inclusions. Other foreign particles such as furnace or ladle slag, ladle and runner brick, etc., must also be absent. The determination of cleanliness at present is usually made by microscopic inspection or macroetching.The rejection of steel for lack of cleanliness is increasing, out cleanliness is one of the most difficult requirements for the manufacturer to fill. The reason for this is that every steel inspector has a different conception of a. clean steel. A material which does not pass the examination of one inspector way be regarded as entirely satisfactory by the metallurgist of an¬other company. The cause of this confusion and disagreement concerning the definition of a clean or a dirty steel is simply that as yet no standardized procedure for the determination of impurities has been proposed and generally accepted, since many variables are encountered which interfere with the development of a satisfactory method. An idea of the complexity of this situation will be obtained from the following pages.A Survey of Proposed Analytical MethodsAlthough no analytical method has been accepted, many procedures have been proposed, as may be seen in Table 1. Therein are listed 16 of the better-known processes, pith references to the work of their originators, their mechanisms of determination, and their applicabilities. Among these is included the electrolytic method developed by one of the present authors, and some comparison between this and previously proposed procedures may be obtained by a study of the table. It appears that this new method Las many advantages over the others, and this paper presents a critical Study of its value."

May 1, 1933

By I. L. Follington

This paper describes the research and development programme to develop a prototype underground auger mining system aimed at developing and demonstrating an underground auger mining system able to provide economic access to thinner (<1.8 m) coal reserves of South Africa. Data concerning the performance of modern coal augers under South African coal mining conditions were gained from a proven surface auger which operated across a range of coal types. These data were analysed and considered in conjunction with historical information regarding previous attempts at building underground augers dating back to the 1950s. Drawing on these data a prototype underground auger mining system, the BryDet BUA 600 underground coal recovery auger, was designed and manufactured by the BryDet Development Corporation in collaboration with Eskom and Cutting Edge Technology Pty Ltd with support from Anglo Coal and the Ingwe Coal Corporation Ltd. The prototype BryDet BUA 600 underground coal recovery auger commenced trials in March 2000 at the Matla Mine near Witbank in South Africa. The initial trials were undertaken in an open cut to facilitate the commissioning and training associated with a prototype mining machine. A total of 30 holes was augered in the box cut before the machine moved underground. The prototype BUA 600 first achieved the target penetration depth of 80 m in its third hole. The prototype BUA 600 is a new underground mining system which has passed early testing with ?flying colours? and could provide access to extensive underground coal reserves unmineable by conventional mining techniques both in South Africa and elsewhere around the world.

Jan 1, 2001

By David Mitchell, Daan Delport, Frik Marx, Mike Shapiro

The use of copper cooling elements to enhance refractory lining life in pyrometallurgical vessels is common in modern furnace design. Copper elements typically incorporate a base panel with cast in cooling passages and an integral extended surface (formed of pins, fins or similar) onto which suitable refractory material is cast. The metallic, conducting parts are located towards the cold face of the lining, with the refractory material interposing between the coolers and the process. The coolers are designed to arrest wear of the refractory material by freezing a layer of slag or partially reacted material onto the hot face, thereby rendering the lining inert to further attack [1]. These coolers have achieved success in new furnaces and relining of existing vessels. The freeze layer is prone to mechanical damage during operational and process instability. The coolers must be capable of extracting the additional heat flux under upset conditions to facilitate rapid self-repair of the freeze layer and prevent further refractory wear in the intermittently exposed areas. However, operational experience has shown that the high heat flux capabilities of the copper coolers have some disadvantages, especially in processes producing vapours which form corrosive compounds when condensing onto the cold surfaces of the coolers. When corrosive conditions develop, the entire composite will fail due to loss of structural integrity, and as a result of leaks from the cooling water passages. This paper describes recent developments in the approach to the design and manufacture of copper cooler panels customized to achieve specified heat fluxes and temperature profiles, thereby reducing the formation of corrosion mechanisms in applications with corrosive gaseous environments and enhancing refractory lining life. Condensation formation prevention is achieved by adjusting the geometry of the cooler and selection of suitable materials of construction.

Jan 1, 2007

Atlas Copco Construction and Mining Australia identified a number of issues in regard to the skill levels, labour turnover and productivity of our service technicians. In 1994 we were experiencing a labour turnover rate of 42 per cent per annum amongst our technicians. Exit interviews were held with each individual and one of the major areas of dissatisfaction was the degree of product training provided on our equipment, compared to what is required to be competent across the range of our products. These tradespersons were prepared to accept the reduced remuneration that an OEM offers, for the benefit of comprehensive, professional training that, in theory, could be provided. The truth is that we were achieving approximately 40 per cent of our target for training hours because of the demands of field service, pre-deliveries, etc. So, the summary was the same as the industry was experiencing at that time because of skilled labour shortages, production demands, etc people were employed and thrown in at the deep end. A recipe for failure that will be successful every time.

Jan 1, 1998

By E Westthorp

Final mine sealing of BMA’s Crinum North mine, near Emerald, Queensland was undertaken in December 2015. Due to the benign atmospheric environment at Crinum North, the Queensland Mines Rescue Service (QMRS) G&#243;rniczy Agregat Gasniczy (GAG) unit was utilised to reduce oxygen levels throughout the underground atmosphere as part of the final sealing process.The GAG was utilised by way of a vertical borehole from the surface to seam to successfully reduce oxygen levels throughout the underground mine workings. Application of the GAG unit enabled the underground mine to be classified as stable and inert within days of the GAG operation, and subsequently cease gas monitoring at Crinum North. The data and information obtained from this activity provides valuable information to the underground coal mining industry on successful application of the GAG in realistic situations.This paper discusses the strategy used for sealing, the assisted inertisation and the results obtained from the application of the GAG unit. It discusses both the overall results and gives a detailed review of the gas monitoring data obtained via the tube bundle and real-time system, both during and following the use of the GAG unit.Gas monitoring results obtained and the strategy used are critical to share with the industry to obtain a better understanding of how the GAG unit works, and how it can be applied for emergency preparedness, emergency response or planned inertisation.CITATION:Westthorp, E, 2017. A review of the strategy and gas monitoring results obtained during the use of Queensland Mines Rescue Service GAG unit at Crinum North mine, in Proceedings Australian Mine Vent Conference 2017, pp 309–318 (The Australasian Institute of Mining and Metallurgy: Melbourne).

Aug 28, 2017

By Shawn Collins

BACKGROUND The history of the Pine Point Mine is a rich one. This property once boasted one of the largest and most profitable lead-zinc mines in Canada&apos;s long and storied mining history. The Pine Point mine used open pit technology to extract the ore, but they faced several challenges. In addition to logistics problems with haul distances and metal prices, the mine faced the challenge of a large in flow of water from the Great Slave Lake. Eventually, the Pine Point Mine was closed leaving behind a large deposit of lead-zinc ore. Following the closing of the Pint Point Mine, Tamerlane Ventures Inc. acquired this property which includes approximately 70 million tonnes of lead-zinc reserves. The initial phase of this project will concentrate on the R-190 deposit as a test site to prove their new approach for extracting the ore. The R-190 reserve is believed to have approximately 1,014,000 million tonnes of high grade ore varying from 5% to 52% combined lead-zinc. Once the pilot project proves the approach is valid, the process will be repeated in approximately 33 other ore bodies on the property. This paper is written to discuss the design process to determine the most effective means of placing production and service equipment in the same shaft. Currently the design work and the mining scheme is complete, but lead-zinc pricing has prevented Tamerlane Ventures Inc. from moving forward with the project.

By J. D. Bliss, G. J. Orris, W. O. Menzie

"Analysis of gold placer data from gold placers throughout the world suggests that gold grades and volumes cannot be used to distinguish between most types of gold placers. Only the alluvial plain and fan placers are significantly different among the types of gold placers considered. Gold grades and volumes change when working gold placers go from small-volume methods to large-volume methods. The small-volume methods are either of the surface or subsurface (drift mining) type. The odds that a gold placer will be dominantly worked using small volume methods at the surface are about 5:3. Once small volume mining has occurred, the odds against subsequent large-volume mining are about 4:1. If a placer deposit is suitable for large-volume mining, and the amount of gold produced from small-volume mining was reported, an estimate of the remaining gold (log10kg) can be made using the following equation:The relationship shown by this equation suggests that very large gold placers have over half their total gold content in the rich gravels appropriate for small-volume mining. These relationships in conjunction with other data and computer simulation can be used to estimate placer gold resources for an area targeted for mineral resource assessment. IntroductionGold placers have been an important source of gold throughout man&apos;s history and may have been one of the first sources-dating back to around 6000 B.C. (Gregory, 1980). From the primitive basket to the modern floating dredge, a variety of methods have been used to work gold placers. Placers are found in a wide spectrum of geologic and climatic settings. They have been classified by using a mixed set of criteria including age (Recent, Tertiary), climate (desert), fluvial position (modern channel, bench, alluvial fan), environment of deposition (eluvial, alluvial, residual, beach), type of transport (stream, wind, glacier), and whether the placer is buried or at the surface (Boyle, 1979; Wells, 1969). Several mining methods have usually been used to extract gold from anyone placer."

Jan 1, 1987

By Gary L. Seider

Helical screw piles are used in various applications including the underpinning of distressed foundations and as deep foundations for new structures. At present, maximum design loads range between 12.5 and 50 tons. Helical piles installed with in-situ grouting of the central steel shaft are a relatively new type of deep foundation, which have extended the present maximum design loads to the 100-ton range. Vickars & Clemence discussed this new foundation system in a paper presented at GEO-Denver 2000 in Denver, CO. Over the past three years, grouted shaft helicals have been used successfully on remedial and new construction projects all across North America. The authors have studied several construction projects in a variety of soil conditions to compile a list of practical design guidelines. Those guidelines include installability of grouted shaft helicals based on soil type, equipment requirements, grout selection, and theoretical vs. actual load capacity. In a number of cases, full-scale, field load tests were conducted in both granular and cohesive soils and the results broken down between tip resistance on the helix bearing plates and friction resistance on the grouted shaft. Data is presented which will further efforts to develop a design model and method to accurately predict the axial and lateral capacity of grouted shaft helicals.

Jan 1, 2003

By S. Ngidi

Palabora Mining Company operates a low grade underground copper mine situated in the Limpopo Province, South Africa. Full production was first reached in May 2005 after a successful transition from an open pit operation to an underground block cave operation. The operation faces a number of technical and operational challenges, not the least being fragmentation of a competent rock mass and external dilution. The cave is subdivided into three main sectors being the east, the west and the central sectors. Caving was initiated from the weaker central sector, which has the majority of its drawpoints located directly under the open pit bottom currently filled with about 130 million tons of waste material from the pit wall failure incurred in 2004. About 48% of the ore reserve has to be extracted from the western sector, which has a much courser fragmentation compared to the other two sectors and only 25% from the central sector with the finest fragmentation. The main constraint during the ramp-up stage has been secondary breaking of drawpoint blockages. Ground-breaking secondary breaking and cave management initiatives and practices have made it possible for Palabora to realize and sustain high production rates.

Jan 1, 2007

By T. G. Joseph

Mines must manage variability from within their operations as well as those imposed upon them by external forces. This paper provides a framework to manage both internal and external variability through the review and adjustment of the mine plan where applicable to minimize lost production and maintain operational safety.

Nov 1, 2011

By G A. Ekama

This paper describes a novel system for the biological sulfate reduction (BSR) of acid mine drainage (AMD) using primary sewage sludge (PSS) as carbon source in an upflow anaerobic sludge bed (UASB) reactor configuration. A UASB reactor was operated at a temperature of 35¦C and it received PSS (1875 mg/L COD) augmented with sulfate (1500 mg/L SO42-). The experimental results indicate that a high treatment efficiency was achieved at more than 90 per cent sulfate reduction at a liquid hydraulic retention time (HRT) of 13.5 h. In this study, the effects of various operational parameters were also investigated. The effect of a biomass recycle stream from the top to the bottom of the sludge bed was found to initiate rapid BSR from the bottom of the bed. Profile tests showed that effective and immediate sulfate reduction was achieved as soon as the influent entered the reactor. From these results, it can be concluded that the UASB configuration using PSS as energy source would be a viable method for the BSR of AMD.

Jan 1, 2009

By J. Wennerstrand

Slender steel piles have found an increased use in Sweden in resent years. These piles are often driven throw soft normally consolidated clay to refusal in till or at the rock surface. In contrast to most other piles the bearing capacity with regard to failure of the shaft is in many cases smaller than the bearing capacity with regard to failure of the soil or rock at the lower end of the pile. Imperfections such as deviations from a straight line of the pile centerline and residual stresses in rolled and welded profiles are important for the capacity of the pile shaft. Even thow the second order moment caused by initial deviations in piles is only half of that in a column with the same slenderness, imperfections can and should be accounted for in much the same way as for columns.

Jan 1, 1989

By C. Özgen Karacan

Gob gas ventholes (GGV) are used to control methane inflows into a longwall operation by capturing it within the overlying fractured strata before it enters the work environment. Thus, it is important to understand the effects of various factors, such as drilling parameters, location of borehole, applied vacuum by exhausters and mining/panel parameters in order to be able to evaluate the performance of GGVs and to predict their effectiveness in controlling methane emissions. However, a practical model for this purpose currently does not exist. In this paper, we analyzed the total gas flow rates and methane percentages from 10 GGVs located on three adjacent panels operated in Pittsburgh coalbed in Southwestern Pennsylvania section of Northern Appalachian basin. The ventholes were drilled from different surface elevations and were located at varying distances from the start-up ends of the panels and from the tailgate entries. Exhauster pressures, casing diameters, location of longwall face and mining rates and production data were also recorded. These data were incorporated into a multilayer-perceptron (MLP) type artificial neural network (ANN) to model venthole production. The results showed that the two-hidden layer model predicted total production and the methane content of the GGVs with more than 90% accuracy. The ANN model was further used to conduct sensitivity analyses about the mean of the input variables to determine the effect of each input variable on the predicted production performance of GGVs.

Jan 1, 2009

The molecular structures of isobutyl xanthate (IBX), diisobutyl dithiophosphate (DIBDTP), O-isobutyl-N-ethyl thionocarbamate (IBETC), O-isobutyl-N-ethylcarbonyl thionocarbamate (IBECTC) and O-isobutyl-N-ethylcarbonyl thiourea (IBECTU) were fully optimized using density functional theory (DFT) at the B3LYP/6-31+G(d,p) level with the integral equation formalism for the polarizable continuum model (IEF-PCM) in the aqueous phases. The effects of the polar groups in these thiol molecules on their collecting performances were determined by the energies and compositions of frontier molecular orbitals and the atomic charge values. Our results indicate that the sulfur atom(s) in IBX, DIBDTP, IBETC, IBECTC, or IBECTU molecule is the centre of reactivity. And the collecting abilities of these reagents for copper sulfide minerals follow the order as: IBX > IBECTU ? DIBDTP ? IBECTC > IBETC, and the order of their selectivities against pyrite is suggested as: IBX < DIBDTP < IBETC < IBECTU < IBECTC. The theoretical analysis provides an insight into the collecting powers of these collectors, and offers an atomic scale approach to understand the experimental data available in the literature. Keywords:xanthate; dithiophosphinate; thionocarbamate; thiourea; density functional theory; structure-activity relationship; copper sulfide mineral

Feb 27, 2013

By Maureen E. Lipkewich

Education builds long term awareness, acceptance and support for responsible mineral resource development. The MABC Education Program is an award winning education partnership with British Columbia classroom teachers that has helped over 5400 teachers with resources and other learning opportunities. Each year, thousands of students begin, and continue, to learn about our modern mineral industry as a result of this teacher-written program. The CIM network has an integral role in the future of mineral education in today?s classrooms in Canada and programs of this caliber are vital to our future. The industry needs help in raising awareness of the benefits of modern mining and teachers need help in acquiring that information.

May 1, 2002

By John F. MacDonald

This paper describes the driving of a 400 m long by 25 m diameter highway tunnel through sensitive, overconsolidated silts and clays. The design concept requires the construction of the permanent support system, consisting of 24 concrete filled perimeter drifts, before excavating the mass core. General construction procedures used during the construction of the perimeter drifts are described.

Jan 1, 1985

By Warren E. Wilson

THE transportation of solids in pipe lines is a matter of deep concern in many fields of engineering. Much experimental and theoretical work has been done in an effort to devise means of designing pipe lines that will satisfactorily transport given solid loads, but there remain many unanswered questions in this field. The present discussion will be confined to a rather narrow portion of this field and will endeavor to point out certain factors that may well be considered when comparing the relative economy of various installations. The data have been presented previously but a new interpretation was prompted by a suggestion in a paper by Professor O&apos;Brien,1 of the University of California, that the friction work per pound of dry material should be considered in determining the relative efficiency of various installations. This method of considering relative economy in various pipe lines leads to some rather unexpected conclusions, especially with reference to the economy of large pipe sizes. A previous suggestion by the writer3 concerning the economy of a rather peculiar type of installation is strengthened. It is not believed that the considerations set forth herein apply directly in the case of dredge lines, where economy is largely a matter of a high rate of pumping in order to reduce the unit overhead charge. However, it is believed that some value may be gained from these considerations in cases involving the disposal of a fixed amount of solids per unit time with a minimum expenditure of energy and at a low cost for replacement of worn pipes. Such situations are not uncommon in the disposal of mill tailings and the disposal of solids deposited from irrigation waters. It was found that data leading to general conclusions for various pipe sizes were not available but certain definite trends are indicated and methods of analyzing available data are presented in the hope that they may be of assistance in preparing engineering estimates on designs of pipe lines of the type described above. ENERGY. REQUIREMENTS Carrying out the idea contained in Professor O&apos;Brien&apos;s paper concerning the method of computing energy required to transport solids, the following analysis leads to some rather interesting conclusions. Let us represent: [Solids load in terms of mass per unit time by W Ratio of mass of suspended solids to total mass of mixture flowing by p Volume rate of flow of mixture by Q Length of pipe by L Slope of energy grade line by s Mass per unit volume of solids by m, Mass per unit volume of liquid by ml Mass per unit volume of mixture by m,,, We then have as an expression for the solids load: W = pQm¬] The work done per unit mass, P, on the mixture to move it along the pipe the

Jan 1, 1945

By Vladimir G. Kochnev

Crushing and grinding account for the major portion (60 to 80 percent) of the overall expenses for ore processing. Autogenous (AG) and semiautogenous grinding (SAG) have been considered a step forward in comparison to conventional grinding circuits with several stages of crushing and using ball (and/or rod) grinding mills (Bassarear, 1982, MacPherson, 1989, Pithois, Casalis, 1983, Maripuu et al., 1983). However, there remains room for improvement to existing AG and SAG technologies and both technologies have immense economic benefit potential. Experience gained by the Technics & Technologies of Disintegration Ltd. (TTD) in the research of grinding processes shows that grinding in AG and SAG mills can be performed in a more effective way. The company&apos;s approach comprises the following elements: ? Novel mill design. ? New liners and lifters. ? Novel discharge grid design. ? Technique of treating material of critical particle size. Comparative tests that demonstrated the usefulness of these innovations are described in this article. Currently, there are hundreds of AG and SAG mills in operation throughout the world. Application of new internal elements of the mills and reconsideration of the circuit design of the existing grinding equipment using present technological solutions would significantly increase the throughput rate and diminish power requirement.

Jan 1, 2008

In 1953, Dr. N. H. Fisher of the Bureau of Mineral Resources, acting on behalf of the Society of Economic Geologists, which is considering the sponsoring of a uniform system of nomenclature for ore reserves, enquired from the Australasian Institute of Mining and Metallurgy whether it had ever considered this subject and particularly whether it had ever set up any standard definitions or specifications with regard to ore reserves.As this had not been done, but was thought to be desirable, the Council of the Institute appointed a Committee consisting of H. H. Dunkin, Associate, Professor of Mining Engineering, University of Melbourne (Convenor), E. A. Rudd, Professor of Economic Geology, University of Adelaide, I. N. Campbell, Chief Geologist of Western Mining Corporation; and the writer to consider and report on this supject.In December 1953, the Committee submitted its first report to the council and this report (reproduced here as an Appendix) was widely circulated among member companies, and engineers, with an invitation to comment on the proposal. A large number of, replies was received and studied.After studying the replies the Committee issued a second report in part as follows:-From these replies we have learned that the suggestions made in the first teport of the Committee are unacceptable to most of those interested, on one or all, of the following grounds;-(a) number of categories,(b) definition of categories;(c) nomenclature.

Jan 1, 1955