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By John A. Reeves

The unit-train concept of moving raw materials .is considered by many railroad men as the most signifigant contribution to reducing rail freight costs since the introduction of the diesel locomotive. The idea, which involves assigning railroad equipment to only one haul and keeping the equipment rolling results in the maximum utilization of equipment. For example before the unit train was plaged in servige on coal hauled to one of Mid. Continent's customers, about 900 cars and 9 locomotives were needed to move the coal requirements for this plant, compared with. 250 cars and 6 locomotives used by the present scheduling of unit trains. If the economics of unit-train movements are to be achieved, coal companies no longer can use railroad cars as small storage bins on wheels to accumulate their coal in trainload shipments, but, rather, must build large bins which incorporate facilities for the rapid loading of railroad cars in a minimum length of time. In this manner railroad equipment is operated at a high degree of efficiency 'with consequent dollar savings. After negotiations between Mid-Continent, the customers and the Railroad, it was decided a unit train loadout and storage facility at Carbondale was required in order to reduce the delivered price of coal to the customers and thereby contribute to the reduction in the cost of manufacturing steel. Carbondale was selected as the bin site location, because the cost of constructing a railroad to Redstone could not be justified for the tonnages anticipated.

Jan 1, 1969

By Alexandre Aparecida Morais

No processo de lingotamento contínuo de placas, o controle de fluxo de aço líquido entre o distribuidor e os moldes pode ser realizado através de tampão refratário ou válvula gaveta. Quando se usa o controle via tampão refratário, aproveita-se o mesmo para reter um volume mínimo de aço no distribuidor, visando efetuar a partida do veio. Este volume de aço é importante para evitar o congelamento da primeira porção de aço e prevenir o arraste de impurezas existentes no fundo do distribuidor para o molde. Já quando se usa o controle via válvula gaveta, para acumular o volume de aço necessário, utiliza-se de outros “artifícios”, como o uso de anteparos metálicos em forma de bujões, cuja eficiência é limitada. Visando melhorar o desempenho de partida das máquinas com controle de fluxo de aço distribuidor-molde, via válvula gaveta, desenvolveu-se o chamado tampão flutuante de fibra cerâmica, cujas funções principais são: equalizar o nível de aço para proporcionar uma partida normal e impedir que impurezas arrastadas pela primeira porção de aço, se dirijam para os veios. Este trabalho mostra o desenvolvimento pioneiro desta técnica para distribuidores de aços planos na ArcelorMittal Tubarão.

Jul 30, 2018

Recommendations from 44 mining industry workshops are summarized and reviewed in the context of Bureau of Mines research and development programs on-going during the period 1974-1977. Approximately 1,000 specific recommendations for research and development are summarized in a systematic and comprehensive format appropriate for review by mining research and development program managers. Relevant Bureau of Mines research programs are briefly described and some opportunities for future research and development are identified.

Jan 1, 1979

By C. Hilgendorf, J. Gingerich, J. R. Boniwell, M. Drouin, D. David on, J. Boldy

The initial discovery of gold in the Eastmain River area, 310 km northeast of Chibougamau, was made by Placer Development Limited in 1970. This discovery resulted from the drill testing of an airborne E .M. Target located in an area of extensive glacial overburden, within an unexplored Archean greens tone belt considered prospective for base metal deposits. Intermittent exploration by another company between 1973-1977 failed to obtain promising results and the existing claims were allowed to lapse. In 1981, Placer reactivated the project and initiated intensive exploration during the next two years which included aerial E .M. surveys, claim staking, ground E .M. and magnetic surveys, geological mapping, diamond drilling and attendant borehole P,E.M. surveys. Beginning in 1983, exploration has been conducted on a joint venture basis with Eldor Resources Limited, The greenstone belt under investigation has an arcuate distribution pattern relative to a centrally located granitic core. Occurrences of gold mineralization defined to date are located to the south of the granite along a strike length of 7 km, and appear to be restricted to the lowermost of two mafic volcanic cycles. This lower cycle is dominated by basaltic flows with subordinate rhyolitic flows and pyroclas ties. Concordant, variably magnetic, massive to talcose ultramafic units occur towards the stratigraphic top of the lower mafic volcanic cycle and appear to crudely define areas considered prospective for gold on a regional bases. Economic interest in centered on a s tratabound, siliceous, sulphide-bearing unit hosted in a 15- 25 metre thick sequence of rhyolite tuffs, basalts and intercalated ultramafics, The siliceous ore bearing unit ( interpreted as a recrystallized chert) contains from 10%-30% pyrrhotite and pyrite with subordinate chalcopyri te and minor sphaleri te. Alteration is characterized by mica development, silicification and carbonatization. Garnets are also occasionally present in close proximity to the ore horizon. The sequence is south facing, and overturned to the northeast at 35°-55°. Explora tory drilling in the vicinity of two conductive targets has been on 100 metre centres along a 1 km strike length of the prospective sequence. To the end of 1983, two ore zones (A and B) have been partially drill tested with estimated indicated and inferred geological reserves of 1 million tonnes grading 11.7 g/t gold , 14.7 g/t silver and 0.26% copper. The system is open at depth. This discovery is the result of the effective integration of geophysics and geology with contributions by many over a long period of time. Key events that can be emphasized are: ( 1) initial area selection of a remote greenstone belt in 1969 - albeit for base metal deposits , (2) utilization of an airborne E .M. system which successfully targeted the A Zone in 1970 , (3) the timely reactivation of the project in 1981 and the subsequent recognition that the original discovery represented a sulphide bearing stratabound horizon with implicit volcanogenic connotations , (4) the intensive effort in 1982-83 deploying aerial and ground geophysics coupled to volcanogenic concepts of ore distribution which resulted in the discovery of the B and C Zones in 1982, and (5) the integration of downhole P . E.M. surveys and geology to successfully delineate ore at increasing depths . To the end of 1983 , $2.6 million has been expended, and it is hoped that continued effort will result in the eventual delineation of an economically viable ore deposit for the joint venture partners .

Jan 1, 1984

By Albert L. Toenges

The fuel requirements for industrial and domestic consumers in New England, in normal times, are supplied almost entirely by fuel oil, anthracite, and bituminous coal. A shortage of these fuels occurred during the war. This shortage was caused by: (1) The diversion of oil to military uses; (2) the use of railroad and boat facilities that ordinarily would transport coal for the transportation of war material; (3) the inability of coal mines to apply the increased demand for coal which resulted from the conversion from oil to coal by domestic and industrial consumers; and (4) the increased demand of war industries for coal. Because of this Critical fuel situation, an investigation was made of possible sources of fuel nearer to points of consumption in New England.

Jan 1, 1948

By Thomas M. Larimer

Prior to April, 1961, the coal charge to Clairtonts coke oven batteries was 3" x 0" mine waslied coal having approximately 6.0% to 7.0% moisture. Even at this size and moisture content, the arching, rat-holing and hang-up was excessive and the effective live storage of coal was only 60% to 70% of the rated capacity of the coal bunkers, depending upon the moisture of the coal. In addition, many production delays were encountered in the time and methods required to fill the larry cars. The need for an improved metallurgical coke led to the introduction of pulverized coal to a portion of the plant in 196 1. When the full potential of the pulverizing equipment was realized, we were able to serve seven batteries in our second unit of batteries with pulverized coal through two coal bunkers. The discharge hoppers of these bunkers were equipped with air vibrators to assist the flow of pulverized coal into the larry cars. The vibrators were helpful in this respect but required considerable maintenance and caused damage to the bin plates.

Jan 1, 1968

By D. Brady

When deciding to deploy rescue teams underground the decision makers need to be able to determine that there won?t be an explosion whilst the rescue teams are underground. Previously general body concentrations in areas likely to be travelled were compared to explosive limits on a one off basis with no formal process looking at trends or other areas. A new approach is being adopted that takes into account the rate of change of gas concentrations with triggers set to enable a withdrawal of personnel prior to a possible explosion and influences such a barometric pressure changes. This paper explains the rationale behind the changes made and the advantages and implications of adopting such an approach.

Jan 1, 2012

"In response to needs created by intensive exploration and accelerating expansion of coal mining in the Western provinces, Canadian R & D on coal is progressively widening its scope. Principal interests continue to lie in coal geology, preparation and processing, carbonization, combustion and transportation, but much active work is also in progress with respect to mine environments, mined-land reclamation, and environmental consequences of coal mining, processing and use. Long-range 'basic' research, which characterized much of the R & D pattern in the fifties and early sixties and which was often no more than an attempt to prevent total extinction of a dying industry, has been somewhat de-emphasized, except insofar as it relates to 'safe' coal storage and to coal-based carbons (which are beginning to command attention as pollution control media).In this review, recent exploration, mine development and new preparation facilities are noted, and current R & D in transportation, processing, handling, carbonization and combustion is summarized. Reference is also made to investigations bearing on non-fuel uses of coal (notably as source-materials for carbons and agrobiological products)."

Jan 1, 1970

By M. M. Kirk

Forced-air cooling of cold-mold arc furnaces for melting zirconium and similar metals has been investigated and found to be practical from the stand-point of heat transfer. It is believed that this technique offers a significant reduction in explosion hazard from that inherent in water cooling, the current industrial practice. A copper crucible, with longitudinal, integral-type fins and with an outer jacket to confine the airstream, appears to be the best general design for air-cooled operation. Cutting the fins into short segments and bending the segments to produce a herringbone effect increased the airstream's turbulence and was found, on test, to increase the heat transfer up to 35 percent.

Jan 1, 1959

By Maria Carolina Andrade Teles

Nas últimas décadas, questões ambientais estão motivando novos paradigmas para o desenvolvimento de nossa sociedade. Assim, os compósitos epoxídicos reforçados com fibras lignocelulósicas atraíram o interesse em várias áreas de engenharia devido ao seu baixo custo, baixo consumo de energia durante a fabricação em associação com várias aplicações possíveis. A fibra, que é avaliada no presente trabalho, é extraída da folha da planta do fique (Furcraea Andina), demonstra um grande potencial como reforço de compósitos poliméricos. Este trabalho avaliará o desempenho em ensaio de impacto Charpy, de compósitos com matriz epóxi associada a diferentes camadas de tecido de fibras de Fique. Os resultados mostraram um aumento notável na dureza do entalhe com a quantidade de camadas de tecido de Fique incorporadas. Isso pode ser atribuído a uma desvinculação preferencial da interface fibra / matriz, o que contribui para uma energia absorvida elevada.

Oct 30, 2017

By G. E. Willey

F OR many years, only one grade of structural steel has been used in volume in Canada. Its characteristics have not been altered appreciably and its long use speaks well for its performance. This standard grade of structural steel may be bought and specified as C.S.A. G40.4 steel or the American equivalent, A.S.T.M. A7. The principal limitations and requirements of this specification are shown in Table I. Within the last five years there has been a growing awareness among the steel producers and steel fabricators that economic forces are at work which make desirable the availability of new and better grades of structural steel. Competition from other materials has increased. The use of concrete bridges and pre-stressed concrete beams is a prime example. New sources of steel from outside the country have become a threat to the Canadian industry and its high cost-price structure. The need for improved properties in the steel, to make possible technologic

Jan 1, 1962

By Ralillie Lopes Carvalho

O presente trabalho apresenta um estudo da influência do tratamento de nitretação a plasma sobre a dureza de lâminas utilizadas em prensa-facas de um picador de toras industrial. Tais peças são fabricadas em ligas com alto teor de Cromo e Carbono, assemelhando-se quimicamente aos aços para trabalho a frio AISI da série D. Para o estudo em questão, pequenas amostras das lâminas receberam tratamento térmico de têmpera e duplo revenido,e posteriormente foram nitretadas a plasma por 30, 90, 180, 360 minutos, em temperatura de 450°C, com pressão fixada em 2 Torr e mistura gasosa de 20%N2 e 80%H2. Logo após foram realizadas análises metalográficas com auxílio de microscópio óptico, ensaio de dureza superficial e perfil de dureza com microdurômetro em escala Vickers. Os resultados mostraram que para todos os tempos de tratamento houve endurecimento superficial em relação ao material não tratado, onde o tempo de 180 minutos propiciou a formação de camada com maior valor médio de dureza superficial “1171,20 HV”.

Aug 16, 2017

By C. E. McElroy

"INTRODUCTION The ventilation of working places in mines by jets of air discharged from fan-pipe lines is an important phase of mine ventilation, whether the primary purpose is to dilute gas or dust concentrations or to provide air-motion cooling effect. Jets of similar nature are very prominent factors in the ventilation of enclosed spaces, such as buildings and ships. The effectiveness of such jets depends on the distribution of the air in the jet streams, a subject on which the little definite information previously available applied to jet discharge into large, open spaces under conditions quite different from those ordinarily associated with fan-pipe discharge in mines.The results of an initial series of experiments on the discharge of air from fan-pipe lines in mine openings have been described. 3/ This report presents the results of a second series of experiments and compares the results of both series with theory and experiment on jet discharge into large, open spaces. The results of this second series confirm and supplement those of the initial series, in which a 10-inch pipe discharged into an 8- by 8-foot develop¬ment end through seven short discharge pieces of different designs. In the present series the same 10-inch line was used, but the discharge was through 10- to 30-foot lengths of 5-inch, 10-inch, and 20-inch-diameter pipes and through a 20-foot length of 29- by 3-inch pipe. Tests were made with the air discharged into a closed drift or development end, as in the previous series (in which case the discharged air returned past the end of the pipe) and into an open drift (in which case the discharged air did not return past the end of the pipe but continued out along the drift). Test conditions corresponded to the discharge of a jet into a channel closed at one end; in one case, the discharge was directed toward the closed end and in the other toward the open end. The former typifies fan-pipe ventilation of development ends and the latter an abrupt increase in the sectional area of an airway. In both the flow had to pass from jet to open air against some resistance.The tests were made in the Mount Weather Testing Adit of the Bureau at Bluemont, Va., on the pipe line installed for ventilating the adit, and extended from late September to mid-November 1940. Preparations were made for directly comparable series of experiments on the injector effect of fan-pipe discharge in an open drift and on free expansion in large, open spaces, but these test programs were .first postponed in favor of other work and finally abandoned until the war is over."

Nov 1, 1943

By J. H. Tylczak

The Bureau of Mines studied the effect of alloy additions on abrasive wear of low-alloy steels. A dry-sand, rubber-wheel abrasion test appa-ratus using ASTM G65-Sl procedure B was used for the abrasive wear tests. Eighty-six material heat-treatment combinations were abrasion tested. Results of these tests were analyzed statistically using regression analysis to see if additions of Cr, Mn, Mo, Ni, Si, AI, Cu, and S were significant in affecting the abrasive wear rate of low-alloy steels. Regression analysis was also used to confirm hardness and C affect on the abrasive wear rate of these steels. It was found that for all the steels taken as a group, increased amounts of Mn significantly reduced the wear rate, while increased amounts of Mo and S1 increased the wear rate. Analysis also confirmed previous research done by others, that increasing hardness and amounts of C reduced the wear rate. For the hardened steels taken as a class, only increasing amounts of C and Mn reduced the wear rate, while increases in Si increased the wear rate. In the class of unhardened steels, increases in C, Mn, and S re-duced the wear rate, whereas increases in Mo increased the wear rate. The steels with the best resistance to wear were two hardened experimen-tal steels similar to AISI 1055 and AISI 107S.

Jan 1, 1986

By Thomas J. Ferree

"IntroductionThe objective of this chapter is to provide important criteria relating to the operation and maintenance of spiral concentrators and Reichert cones, so that optimum performance can be achieved and maintained in a mill circuit. Little space will be devoted to the theory of the forces of separation or the technical details of the devices, as that in(ormation is available from other sources. The discussions in this chapter will be presented in a manner that should be interesting and useful to anyone who may be exposed to these methods of gravity separation. It is most important for the reader to understand that each application of the equipment should be considered on its own merit, as no two suites of minerals respond exactly alike in mineral processing circuits. The information herein should be useful as a guide toward increasing the metallurgical efficiency of the processes, irrespective of the type of minerals being concentrated.It is highly recommended that certain tools be made available to the personnel responsible for metallurgical performance of the spirals and cones; these include a set of standard type laboratory screens, a medium quality petrographic microscope, and a vanning plaque or gold pan. These devices, when used in conjunction with a basic understanding of the mill circuit, provide immediate knowledge on the characteristics of any sample in the mill circuit. The information gained by visual evaluation of sized fractions of products can solve many of the basic problems of mineral beneficiation, and at the same time increase the interest of the non-technical personnel associated with the plant operation. There are many problems associated with obtaining satisfactory performance from a mill operation. Many of the problems have to be solved using a technical approach. Some of the problems, however, can be solved with practical knowledge and common sense. It is hoped this chapter can provide a guide to both techniques."

Jan 1, 1989

By C. Melvin Lepper

High-resolution shallow seismic reflection methods are being used by the Bureau of Mines to map underground geologic features in coal mines. These features include faults, channel sand, washouts, rolls, and steep dips. The seismic method is proving useful for locating all of these at reasonable cost and with better definition than available with drill programs alone. This report provides a capsule description of the techniques and their application to mine planning.

Jan 1, 1976

By Richard A. Dick

In this report commercial blasting compounds are classified according to their nitroglycerin (or equivalent explosive oil) and ammonium nitrate content as dynamites, gelatins, blasting agents, military explosives, and blasting , accessories. The ingredients and more significant properties of each explosive are tabulated and briefly discussed. Data are summarized from various handbooks, textbooks, and manufacturers' technical data sheets, together with the author's personal experience; however, this report is not intended to be a technical handbook, since it does not deal with blasting techniques. Instead, it seeks to acquaint the reader with the great variety of explosives, available, their advantages and disadvantages, and their general areas of application. Properties discussed are weight strength, cartridge strength, detonation velocity, density, detonation pressure, water resistance, and fume class. The weakness of the strength rating system and the importance of detonation pres- , sure, density, and detonation velocity in rating explosives are discussed. The terms "blasting agent" and "slurry," which are often misused, are defined. Trends indicate that blasting agents (that is, blasting mixtures with none of of the ingredients singly classified as an explosive), particularly high-density slurry blasting agents, will dominate the explosives field in the future.

Jan 1, 1968

By W. E. Brown, P. R. Porath, V. Miller, C. E. Wood, C. Prasky, E. P. Barrett

"INTRODUCTION This investigation was a part at the Bureau of Mines program for the production of critical and essential materials needed for the war.The Boykin Committee for investigating the steel shortage aided in obtaining an appropriation to be expended by the Bureau of Mines in studying the utilization of North Dakota lignite in the manufacture of hydrogen that could be used in the production of sponge iron from low grade ores of Minnesota.OBJECT OF INVESTIGATIONThe investigation was conducted by the Bureau of Mines to ""determine the workability of the proposed bubble-hearth process and its possible use in connection with an experimental plant for the gasification of lignite being operated by the Coal Division of the Bureau of Mines at Grand Forks, North Dakota.ACKNOWLEDGMENTSThis report is one of many on various aspects of the Bureau of Mines program directed toward the more effective utilization of our mineral resources.Investigations of our mineral resources are conducted by the Mining Branch, L. B. Moon, chief, and by the Metallurgical Branch, O. C. Ralston, chief.The scope of the report falls in the province of the Metallurgical Branch, whose activities embrace the separation of difficulty beneficiated ores, the production of pure metals from domestic deposits, the exploration of marginal ore reserves, the recovery of secondary metals, and the improvement of present industrial metallurgical practice."

Jun 1, 1947

By Albert W. Deurbrouck

This report describes the preparation characteristics of 23 coal samples collected from nine of the more significant coalbeds of Fayette County, W. Va. In 1963 almost 5.4 million tons of medium to high volatile B coals of excellent quality for metallurgical and steam markets were produced in Fayette County. Of the 23 coal samples collected 11 would require some upgrading to pro-vide metallurgical quality products, 11 were acceptable as received, and 1 was a noncaking coal. Cleaning these coals to metallurgical standards would require only the removal of the sink 1.58 specific gravity material which would be quite easy as very little near-separating-gravity material was present at this gravity.

Jan 1, 1965

By S. Illendula, B. Q. Li, R. A. Mirshams

"An integrated mathematical model is developed to represent the thermomechanical behavior of the materials and microstructure evolution during metal forging. The model development is based on the finite element solution of the thermoviscoplastic deformation of metals coupled with the internal state variable model describing the microstructure evolution involving work hardening, recovery, recrystallization and grain size distribution. The procedures for the integration of the microstructure model into the macro finite element model are described. Computed results for both macro and micro phenomena during metal forging, such thermomechanical deformation such as velocity field and effective strain rate and materials characteristics such as distribution of grain size and recrystallization volume fraction, are presented.1. IntroductionThermomechanical behavior and material microstructural evolution are two critical, interrelated aspects associated with metal workpiece undergoing large plastic deformations such as encountered in forging processes. In much of the modeling work up to date, these two aspects have been addressed separately. Die designs and forging processes are investigated using finite element based thermomechanical models while material dynamics during forging is studied, more often than not, as a separate subject. For many industrial applications, especially those involving novel, light and high strength materials, it is critical to combine these two aspects into a single, integrated model so that materials dynamics and thermomechanical deformation during forging processes can be considered simultaneously [1], thereby providing required information for intelligent process design and optimal process control."

Jan 1, 1998