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THE 144th* meeting of the American Institute of Mining and Metallurgical Engineers was held in New York, Feb. 18 to 21, 1935. It consisted of the annual business meeting, 45 technical sessions at which 216 papers were presented (approximately the same number of sessions and papers as at the previous annual meeting), two sessions of the Board of Directors, three meetings of Section delegates, two formal lectures and two addresses, luncheon Monday, Tuesday and Wednesday for members and guests, six group dinners and eight group luncheons, ten committee meetings, the annual reception and dinner dance, an informal dance, a smoker-dinner and the annual meeting of the Woman's Auxiliary. Attendance was generally greater than for the two preceding meetings; the statistics follow (figures are in the order 1935-1934-1933); total registration, 1609-1534-1475; dinner dance, 577-543-426; dinner-smoker, 490-425-394; informal dance, 279-295-250; women's registration, 179-160-133; general luncheons, 1132-1034-734. The Coal Division held two general sessions on Monday and a symposium on coal-mine ventilation on Tuesday morning. The Committee on Bituminous Planning, Edward Steidle, chairman, presented a report at the Monday morning session. C. B. Huntress, President of Appalachian Coals, Inc., was the principal speaker at the luncheon on Monday, at which Eli T. Conner, Chairman of the Division, presided. Mr. Huntress was preceded by Howard N. Eavenson, President of the Institute, who spoke briefly. The Sectional Committee on Classification of Coal met Wednesday afternoon. A feature of the meeting concerning three Divisions-Iron and Steel, Institute of Metals, Petroleum-was the symposium on Use of Metals in the Petroleum Industry, Thursday morning and afternoon. Five of the papers presented at this symposium have been published in METALS TECHNOLOGY'. Another feature, of general interest, was the Tuesday morning session in the Auditorium, devoted to Federal Government and Mineral Industries. Dr. C. K. Leith delivered the principal address, on "A, Mineral Policy for the United. States." . The Institute of Metals Division held technical sessions Tuesday afternoon and Wednesday. morning and afternoon and on Thursday

Jan 1, 1936

William B. Phillips, Birmingham, Ala.: The questions raised by Messrs. Wilkens and Nitze are in the highest degree interesting to owners of low-grade iron-ores, aizd no less so to blast-furnace managers. If it can be shown that ores heretofore considered worthless can be brought within the limit of economic use, many large and readily accessible deposits may come into market on the one hand, while on the other the possible increase in the output of the furnace per ton of ore used will prove of advantage to the iron-maker. It cannot, of course, be claimed that this process has been employed on a working-scale with respect to iron-ores, and in so far as concerns results on a large scale no one is any wiser than his fellow. Granting that the results obtained in an experimental way (and certainly the experiments were conducted with a great deal of care) can be attained in practice, we would still be facing the question, what it would cost to get them. In the absence of any specific data, we have to fall back on general principles, helped along, as far as possible, by indications afforded by the experiments. I must confess that as regards the Clinton ores, which I have studied to some extent, I am not sanguine of making a ton of 53 to 54 per cent. concentrates from less than 1.75 tons of 40 per cent. raw ore. It may be possible to get the iron in the heads to 56 to 57 per cent., but the lesser richness of the middlings will probably reduce this to 53 to 54 per cent. in the salable stuff. As the authors remark, it is not worth while to discuss the concentration of the better grades of " soft" Clinton ore; for the price at which they are now delivered at the furnaces, and the comparatively limited amount now remaining, render their concentration unadvisable. If it is to succeed in the Birmingham district, the process must be applied to the low-grade soft and hard ores now con-

Jan 1, 1897

In 1939 at the annual meeting of the Australasian Association for the Advancement of Science, held at Canberra, a paper was contributed by E. de C: Clarke and H. A. Ellist in which a plea was made for more "facts" concerning metasomatism near ore-bodies in Western Australia. From time to time writers here, and in other parts of the world, have discussed the alterations in wall rocks of various reefs and lodes, but little has yet been attempted in the matter of accumulation of quantitative data, both chemical and mineralogical, and in the correlation and comparative study of this data. Such a detailed comparative study is needed to determine the economic value of a practical application of our accumulated knowledge of the phenomena of metasomatism.When in 1939 the opportunity offered for an examination of the core from 4 bores recently put down by the Big Bell Mines Ltd., to explore the ore-body of the Corinthian G.M. 10 miles N.W. of Southern Cross, Western Australia it was hoped that some small beginnings might be made of an accumulation of comparative and quantitative data regarding the metasomatism of the wall rock immediately adjacent to this ore-body.By the courtesy of the Big Bell Mines Ltd., the core from the 4 bores was delivered to Survey Headquarters, Perth;in the middle of June, 1939 and copies of assay plans of part of the underground workings at Corinthian, and of the results of assays of the bore cores, were also supplied by the management of the above company.It was not, however, until March, 1940, that it was 'found possible to investigate the core. At that time the writer's colleague, Mr. R. S. Matheson, conducted a: megascopic examination of all the bores and selected material from two of these for possible future chemical analyses. Late in 1940 the writer commenced a microscopic petrological examination of this material.AIM OF THE INVESTIGATIONThe object of the petrological part of this investigation was to determine whether from a megascopic and microscopic examination of the core, any evidence could be obtained indicating changes, in mineralogical composition...

Jan 1, 1942

By J. Q. Ehrgott

INTRODUCTION The U. S. Army Engineer Waterways Experiment Station (WES), under sponsorship of the Defense Atomic Support Agency, has recently developed a unique dynamic high-pressure triaxial testing device (DHT). The device permits acquisition of both axial and lateral deformation data while undisturbed soil and/or rock specimens are subjected to various states of controlled impulsive-type stresses produced by varying both the axial stress and the radial stress rapidly with time. The device is used to develop controlled dynamic pressure pulses within the triaxial chamber fluid on soil or rock test specimens to 3 inches in diameter. Controlled dynamic axial pulse loads are delivered to the specimen by a piston driven by an existing pneumatic ram loader (SECO). The DHT consists of a triaxial cell and a pressure supply and decay system which permits the chamber pressure to be varied with time. Together the DHT and SECO operate in a testing program so as to provide time varying confining pressures and axial loads to test specimens at independently controlled but synchronized programmed rise, hold, and decay times. Rise time is defined as the time from zero load or pressure to peak load or pressure; hold time is the time of constant peak load or pressure; and the decay time is the time from peak load or pressure to zero load or pressure. The maximum dynamic confining pressure attainable is approximately 15,000 psi and the fastest rise and decay times are 3 millisecond (msec) and 20 msec, respectively. This paper presents a description of the DHT, the necessary support equipment, and details of the measurement system. Performance evaluation tests conducted on clay siltstone and a Cretaceous sandstone are presented since the results demonstrate some of the capabilities of the device and show some of its characteristics.

Jan 1, 1971

By C. H. Herty

During the past few years frequent reference has been made to a certain type of iron known generally as "bad iron," "dirty iron," etc., both by steelmakers and producers of iron castings.' Open-hearth operators have claimed that such iron was entirely within the specified limits as to ordinary analysis but it was difficult to make good steel from it. It has been suggested that unreduced material in the iron is responsible, also that most trouble is experienced with the iron when the blast furnace is delivering a product whose analysis is more or less variable. Other reasons suggested are the use of scrap or borings, unsintered flue dust in the burden, a cold hearth, too high a proportion of unsuitable grade of ore, or the form of the carbon in the iron. Accordingly, a subcommittee was appoint at the fall meeting of the Open-hearth Committee of the Americ m Institute of Mining and Metallurgical Engineers held in Pittsburgh in October, 1926, to investigate the reasons for the occurrence of this bad iron and suggest methods for preventing its appearance. This committee enlisted the cooperation of the U. S. Bureau of Mines Experiment Station at Pittsburgh in undertaking a study of pig-iron quality as affecting the open hearth. The following is a report of the findings to date: Method of Testing Inasmuch as a "spell" of dirty iron occurs without warning and may be of short duration, it was deemed advisable to attempt to simulate the conditions existing before and during such a period and compare the quality of the steel made with the normal and with the dirty iron. The Bourne-Fuller Co., of Cleveland, which has a single furnace that supplies

Jan 1, 1929

By Thomas C. Atchison

An understanding of the physical processes involved in breaking rock with explosives will lead to better blasting techniques. In this chapter known rock breakage principles will be outlined, some conjectural ideas will be discussed, and areas needing further study will be pointed out. The principles outlined will serve as a basis for the design of blasting rounds described in the following chapter. 7.2-1. Factors Important to Rock Fragmentation. The efficacy of explosives as tools for rock fragmentation lies in their ability to deliver almost instantaneously large amounts of energy to a limited portion of the rock. When an explosive charge is detonated in a drill hole, its energy is released in a very small fraction of a second in the form of gas at extremely high pressure and temperature. The mechanics of the transfer of this energy to the rock and the resulting breakage are complex and not completely understood. Factors that have been identified as important to the fragmentation process may be grouped in three categories: explosive parameters, charge loading parameters, and rock parameters. EXPLOSIVE PARAMETERS. Explosive parameters known to influence breakage are density, detonation velocity, detonation impedance, detonation pressure, gas volume, and available energy. Detonation pressure is probably the best indicator of an explosive's ability to break solid hard rock. Detonation pressure is roughly proportional to the product of density and the square of the detonation velocity. The relative ability of different explosives to transmit their pressure to stress in a given rock is function of their detonation impedances. Detonation impedance is the product of density and detonation velocity. The volume of gas released in the explosive detonation undoubtedly is of importance, at least in the later stages of breakage, and is probably

Jan 1, 1968

By John Mastoris, Kostis Dragasakis, Kostas Kouklidis, Shkurtë Gashi, Halil Berisha, Jenuz Bulica

Titan Group’s environmental policy and Sharrcem’s Corporate Social Responsibility (CSR) are the driving forces behind the development and implementation of a comprehensive Rehabilitation Plan at Dimce Quarry, which is the main raw material source for Sharrcem Cement Plant since the 1970’s, located in the municipality of Hani i Elezit in Kosovo. Based on an Environmental Impact Assessment Study and the approved Mining Plan and also on the principles prescribed in the Guidelines on Quarry Rehabilitation, released by the Cement Sustainability Initiative of the World Business Council for Sustainable Development (WBCSD-CSI), Sharrcem has adopted a quarry operation and rehabilitation process in line with the best practices in the mining and cement sector. This paper discusses the background for the development of the rehabilitation plan and the results of rehabilitation activities, as have been implemented over the last few years. The main objective of the progressive rehabilitation plan at Dimce Quarry is to restore the depleted pit and return it back to the original land owners for resettlement. To date approx. 3,4Ha of former mining area has been restored by backfilling and levelling of the depleted closed pit and returned back to owners, who have built their houses and turned it into a living area again. This Quarry has turned out to be a real composition and practical example of preserving and returning back the natural resources in a state compatible with the surrounding environment and with respect to the needs of the local stakeholders. The motivation for business to engage in rehabilitation activities in the first place lies in the belief that the development and implementation of a progressive and practical Quarry rehabilitation plan and restitution of the land will deliver significant environmental and social benefits that outweigh the long-term rehabilitation costs, while maintaining the company’s reputation.

Jan 1, 2017

By B. R. Mohal, F. F. Aplan, S. Chander

"The wetting behavior of coal has been determined in the presence of nonyl and octyl series of nonionic surfactants containing polyethoxy groups of different sizes. The wetting behavior was determined by a modified Walker technique and contact angle measurements. The results show that the wetting rate of coal varies with coal rank, structure of the hydrocarbon chain and number of ethoxy groups in the hydrophilic group of the surfactant. A close relationship has been observed between the wetting rates and the short-time advancing contact angles.INTRODUCTIONNonionic surfactants are used in many applications to improve wettability of solids. They can be used as dispersing agents [ 1 ] or dust suppressants [ 2-5] and to control the flotation, flocculation, filtration and flowability of particulates. This study was undertaken to study the effect of a series of nonionic surfactants on the wetting behavior of coal. Two series of surfactants, namely, ethoxylated nonyl and octyl phenols were used. The nonyl phenol series contains a linear hydrocarbon chain containing nine carbon atoms ( CH3 ( CH2 ) 8-C6H4-( OC2H4 )""' where n is the number of ethoxy groups). The octyl phenol series contains a branched hydrocarbon chain containing eight carbon atoms ( ( CH3 ) 3CCH2C ( CH3 ) 2-C6H4-( OC2H4)"").Initial wetting rates - modified Walker techniqueWalker et al. [ 6] developed a sink test to determine the wettability of coal particles. In this technique, coal particles are dropped individually onto the surface of surfactant solutions of different concentrations, and the most dilute concentration in which coal would sink ""instantaneously"" is determined. This technique is a variation of a procedure initially developed by Draves and Clarkson [ 7] to determine the effect of surfactants on wettability of cotton fibers."

Jan 1, 1989

By W Jahn Archer

El rendimiento de extracción de mineral de cobre en Mufulira aumentó durante el periodo de 1971 - 1973. Por ello, los experimentos iniciales se concentraron en tratar de comprobar las potenciales ventajas de un tiempo de flotación prolongado, de forma que se incremente el rendimiento en cobre. En ese sentido, el texto señala las mejoras en los circuitos de flotación a través de la instalación de una celda de flotación DAVCRA en el circuito triturador. Dicha celda se intercaló con el circuito central y en el circuito de residuos.

Jul 1, 1976

By Eldon C. Pattee

Reconnaisance samples of reported beryllium occurrences in Idaho, Washington, Montana, and Oregon were chemically and spectroscopically tested in a mobile laboratory. The two predominant types of occurrences were green beryl associated with Cretaceous intrusions and disseminated aquamarine associated with Tertiary intrusions. Although the beryllium content of known deposits in the Northwest is too low for economic development at present, total submarginal-grade beryllium resources in pegmatites are estimated to be 570,000 to 1,870,000 tons containing 0.024 to 0.167 BeO. A potential source of 500,000 to 700,000 tons of beryllium-bearing tactite in Idaho and Montana averages 0.033 to 0.080 percent BeO.

Jan 1, 1968

An account of milling "methods and costs at Mount Isa Mines Limited up to the year 1938 has been published. The present paper outlines the methods since adopted in the milling of lead-zinc ores and presents a description of the equipment now being provided for the milling of copper ore.The programme approved for the mining, milling and smelting of both lead-zinc and copper ores involves the milling 9f 50,000 tons of lead-:-zinc ore and 35,000 tons of copper ore per month.The crushed ores will be delivered to the surface from alternate levels through No. 2 Ore shaft and conveyed to their respective crude ore bins at the crushing plant. The ores will be crushed and milled in separate circuits in common buildings and the tailings will be stored on a common tailings dump. The water services to the two circuits will be separate.LEAD ZINC PLANTCrushing PlantThe crushing plant described in the previous paper was located adjacent to the Urquhart shaft. The crushing plant had grown considerably over the years by the addition of a 4ft. BY-mons shorthead crusher and a set of Traylor 72 in. x 20 in. crushing rolls and, whilst operating satisfactorily, was difficult to maintain and cramped in many places. As a satisfactory layout for the new copper crushing plant could not be made in the vicinity of the, existing plant, it was decided to construct a new plant on the western side of theconcentrator building and provide identical equipment in...

Jan 1, 1953

The experience of the Committee in connection with securing papers for the Butte meeting in August has shown that authors should begin early on papers contemplated for the New York meeting next February. So many papers come in at the last moment that it becomes exceedingly difficult to have them all read, indorsed, and delivered to the printer in time. Authors should remember that those serving on this Committee are doing so without pecuniary compensation, and it is hardly fair to expect them to devote so much of their time at the last moment from their private affairs. So many papers have to be sent back for corrections of one kind or another, that it is desirable that they be sent to the Committee at least three months previous to the date of the meeting. The Committee desires to be kept informed of contemplated papers on metallurgical subjects particularly. It is hoped that the Institute Transactions can be made an up-to-date record of metallurgical advance of all kinds. For the present, at least, the activities of the Committee include the refining and preparation of the non-metallic products such as phosphate rock, precious stones, cement, lime, gypsum, building stones, etc. Papers covering any of these subjects are desired. General papers covering geological, mining and metallurgical phases of an ore deposit can be sent either to this Committee or to one of the other Committees on Mining Geology or Mining Methods. C. W. GOODALE,Chairman. DARSIE C. BARD, Secretary.

Jan 8, 1913

By Thomas D. Kaufmann

Introduction Mining has always been sensitive to the fluctuating income of downstream customer industries. The industry is now becoming more vulnerable to booms and busts as economic pulsations increase and demand for mining products shows little or no long-term growth. As the general economy has become more cyclical in the last decade, the capital-intensive primary industries have become more aware that timing as well as preparation of survival plans are vital in investment decisions. Strangely, however, some of us have not yet included the business cycle in our feasibility studies. Cyclic prices and volumes and fluctuations in profits and cash flows do not fit our linear models. The increased cyclical nature of our economy is recent and poorly understood. Forecasting peaks and troughs is still more an art than a science. Nevertheless, avoiding business cycle parameters can lead to error in value estimation and contingency planning of new projects. Metal and Mineral Industries More than half the iron and steel, aluminum, copper, lead, zinc, manganese, tin, nickel, molybdenum, cobalt, and chrome that we mine, smelt, upgrade, and recycle goes to construction, transportation, capital goods, and consumer durable industries. All are cyclical. Their products are consumed slowly, so replacement can be postponed in recessions. Purchases of such goods are usually financed by debt, and their customers are sensitive to highly cyclical changes in interest rates. During prosperous periods, people tend to buy capital goods despite high interest rates. Upstream industries also tend to be whipsawed by inventory cycles. With high interest rates and good transportation, downstream fabricators can lighten their inventories during recessions. They know that upstream suppliers can deliver supplies and raw materials immediately, And, with the advent of electronic accounting, the fabricator with timely inventory information can afford to hold fewer contingency stocks. Likewise, when recovery returns, inventories surge back through industry pipelines, accelerating demands on primary supplies. The price elasticity of most primary products is low. Their share of the value of finished products of the industries they supply is generally small. The 60 kg (130 lb) of aluminum in a car is vital. But whether it costs $80 or $130 will not visibly influence the demand for an automobile. With low elasticities of demand, the primary producer is hit with decreases (or increases) in prices and in sales volume, during recessions as well as recoveries.

Jan 6, 1984

5. The medal committee may invite nominations from the membership of the Institute, such nominations to be accompanied by an argument in favor of the award and details sufficient for a proper citation to be drawn. This medal has been awarded as follows: 1927—David William Brunton. 1929—John Hays Hammond. 1928—Herbert Hoover. 1930-Daniel C. Jackling. Miscellaneous Prizes Many of the Local Sections have established or administer prizes for the best paper presented within the year by any junior member. Annual Lectures Howe Memorial Lecture The Howe Memorial Lecture, in memory of Henry Marion Howe, Past President of the Institute, was authorized in April, 1923, as an annual address to be delivered by invitation under the auspices of the Institute by an individual of recognized and outstanding attainment in the science and practice of iron and steel metallurgy or metallography, chosen by the Board of Directors upon recommendation of the Iron and Steel Division. The following were the Howe lectures and lecturers for the years indicated: 1924 What is Steel? By Albert Sauveur. 1925 Austenite and Austenitic Steels. By John A. Mathews. 1926 Twenty-Eve Years of Metallography. By William Campbell. 1927 Alloy Steels. By Bradley Stoughton. 1928 Significance of the Simple Steel Analysis. By Harry D. Hibbard. 1929 Studies of Hadfield's Manganese Steel with the High-power Microscope. By John Howe Hall. 1930 The Future of the American Iron and Steel Industry. By Zay Jeffries. Institute of Metals Lecture An annual lectureship was established in 1921 by the Institute of Metals and it has come to be one of the important functions of the Annual Meeting. A number of distinguished men from this country and abroad have served in this lectureship. The roll is quoted below: 1922 Colloid Chemistry and Metallurgy. By Wider D. Bancroft. 1923 Solid Solution. By Walter Rosenhain. 1924 The Trend in the Science of Metals. By Zay Jeffries. 1925 Action of Hot Wall: a Factor of Fundamental Influence on the Rapid Corrosion of Water Tubes and Related to the Segregation in Hot Metals. By Carl Benedicks. 1926 The Relation between Metallurgy and Atomic Structure. By Paul D. Foote. 1927 Growth of Metallic Crystals. By Cecil H. Desch. 1928 Twining in Metals. By C. H. Mathewson. 1929 The Passivity of Metals, and Its Relation to Problems of Corrosion. By Ulick R. Evans. 1930 Hard Metal Carbides and Cemented Tungsten Carbide. By 8. L. Hopt.

Jan 1, 1930

By T. Sterry Hunt

In my address on the " Geognostical Relations of the Metals," delivered before the Institute on the 20th of February last (Vol. I Transactions, p. 331), I spoke of the rocks in the vicinity of Thunder Bay, Lake Superior, where I indicated two series of uncrystalline rocks resting upon the Huronian schists, the lower one consisting of dark-colored argillites and sandstones overlaid, apparently in slight discordance, by nearly horizontal red and white sandstone and marls, which were compared with those of Sault Ste. Marie, and those of the Portage Lake district, on the south shore. These latter sandstones, according to Brooks and Pumpelly, overlie uncomformably the Keweenaw series of copper-bearing amygdaloids, sandstones, and conglomerates, and are in turn overlaid by the Trenton limestone. I then proposed to call this lower series of Thunder Bay, that is to say, the dark-colored argillites and sandstones which are traversed by the silver-bearing lodes of that region, the Animikie group. Shortly after the publication of that address I received an abstract of a paper on the geology of that region by Professor Robert Bell, read before the Montreal Natural History Society, February 24th. He there confirms the statement made in my address that the gold of Lake Shebandowan occurs in the Huronian, which is also seen to be cut by the silver-bearing lodes just mentioned. Professor Bell, in this paper, proposes to designate both what I have called the Animikie group, and the overlying red and white sandstones, by the name of the Nepigon group, for the reason that the upper series is best displayed about Lake Nepigon. This latter series is by Logan supposed to be overlaid by the copper-bearing amygdaloids with conglomerates and sandstones of the north shore (apparently identical with those of Keweenaw); and the whole together, inclnding the Animikie group, constitute his Upper Copper-bearing group. These copper-bearing strata are by him supposed to be overlaid by the red and white sandstones of St. Mary, which are apparently the same with those sandstones which, according to Brooks and Pumpelly, overlie unconformably the similar cupriferous rocks of Portage Lake, and are, in their turn, overlaid by the Trenton limestone. Thus the sandstones which at Thunder Cape overlie the Animikie group are by Logan placed in the midst of the Upper Copper-bear-

By T. Sterry Hunt

IN my address on the " Geognostical Relations of the Metals," delivered before the Institute on the 20th of February last (Vol. I Transactions, p. 331), I spoke of the rocks in the vicinity of Thunder Bay, Lake Superior, where I indicated two series of uncrystalline rocks resting upon the Huronian schists, the lower one consisting of dark-colored argillites and sandstones overlaid, apparently in slight discordance, by nearly horizontal red and white sandstone and marls, which were compared with those of Sault Ste. Marie, and those of the Portage Lake district, on the south shore. These latter sand-stones, according to Brooks and Pumpelly, overlie unconformably the Keweenaw series of copper-bearing amygdaloids, sandstones, and conglomerates, and are in turn overlaid by the Trenton limestone. I then proposed to call this lower series of Thunder Bay, that is to say, the dark-colored argillites and sandstones which are traversed by the silver-bearing lodes of that region, the Animikie group. Shortly after the publication of that address I received an abstract of a paper on the geology of that region by Professor Robert Bell, read before the Montreal Natural History Society, February 24th. He there confirms the statement made in my address that the gold of Lake Shebandowan occurs in the Huronian, which is also seen to be cut by the silver-bearing lodes just mentioned. Professor Bell, in this paper, proposes to designate both what I have called the Animikie group, and the overlying red and white sandstones, by the name of the Nepigon group, for the reason that the upper series is best displayed about Lake Nepigon. This latter series is by Logan supposed to be overlaid by the copper-bearing amygdaloids with conglomerates and sandstones of the north shore (apparently identical with those of Keweenaw) ; and the whole together, including the Animikie group, constitute his Upper Copper-bearing group. These copper-bearing strata are by him supposed to be overlaid by the red and white sandstones of St. Mary, which are apparently the same with those sandstones which, according to Brooks and Pumpelly, overlie unconformably the similar cupriferous rocks of Portage Lake, and are, in their turn, overlaid by the Trenton limestone. Thus the sandstones which at Thunder Cape overlie the Animikie group are by Logan placed in the midst of the Upper Copper-bear-

Jan 1, 1874

Excessive dust generation from unpaved mine haul roads is a problem common to most surface mining operations. While optimal road wearing course material selection parameters reduce the inherent dust generation potential, they do not totally eliminate fugitive dust. Many different classes of suppression or palliative treatments are available for mine haul roads and this paper initially ascertains basic selection guidelines, using a set of ideal dust palliative product, application and performance parameters based on mine road-user requirements. An evaluation and modelling methodology for truck generated fugitive dust emissions is developed as a basis for the comparative assessment of dust control strategies. For water-based spraying, a watering model was developed to estimate individual mine road watering frequencies for characteristic site parameter combinations during summer and winter operating conditions, for a required level of control or maximum dust defect. This forms the base-case scenario with which to compare the performance of other types of dust palliatives under the same conditions. Finally, a basic palliative economic evaluation model is introduced with the aim of identifying and costing the establishment, application and maintenance rejuvenation activities associated with the use of chemical palliatives. While palliative cost and performance is generally site specific, it is shown that under certain combinations of conditions, the use of dust palliatives has the potential to deliver cost savings when compared to water-based spraying.

Jan 1, 2007

By William S. Sanner

A demonstrated reserve base (DRB) of bituminous coal suitable for cokemaking has been estimated based on the latest published information on U.S. coal reserves. Bureau of Mines analyses of raw coalbed samples were used to classify the coals as low-, medium-, and high-volatile bituminous and grade them as premium, marginal, and latent coking coals. Coal rank was used as the basis for identifying coking coals, and ash and sulfur content were used to determine coking coal grade. The demonstrated reserve base of coking coal for the entire United States is 162.67 billion tons. However, only 18.96 billion tons are premium (metallurgical) grade, and between 80 and 99 percent occurs in the Eastern States. The demonstrated reserve base of marginal-grade coking coal is 31.3 billion tons; more than half the marginal reserve base is in the Eastern States, and most of the medium- and low-volatile marginal coals are in the Eastern States. The Eastern and Midwestern States contain most of the latent-grade DRB of 112.4 billion tons; most (106.6 billion tons) is high-volatile coal, and 98 percent of the medium- and low-volatile latent coals occur in the Eastern States. Based on the worst assumption, which assumes that only premium-grade coals are used for cokemaking, the DRB for high-volatile coal would suffice for 127 years, the medium-volatile coal for 80 years, and the low-volatile coal for 83 years.

Jan 1, 1979

By Candice Stevens

The Territory of Afars and Issas is to receive its independence from France on June 27, 1977. The Territory's economic income was based on entrepôt trade through the port of Djibouti and trans-shipment of goods on the Chemin de Fer Franco-Ethiopian (CFE) railroad. The Territorial budget was scheduled to in- crease from $32.6 million3 in 1976 to $36 million in 1977, despite severe shortfalls in 1976 stemming from inflation and a persistent balance-of-trade deficit. Subsidies from France continued to sustain the economy, and the French pledged to provide approximately $140 million in aid annually after independence. In 1976, financial agreements were concluded with a number of Arab oil-producing countries, including Saudi Arabia which granted $10 million toward development projects. The new Republic of Djibouti is scheduled to become the 49th member State of the Organization of African Unity (OAU) and the 21st member of the Arab League, and to receive aid from their financial institutions. The port of Djibouti and the CFE railroad constituted the Territory's main economic resources. Traffic at the port greatly

Jan 1, 1980

By Jim Salley, Mohammad Saleem, Indra Banerjee, Kevin Sapp

"On underground construction projects, effective Quality Management is essential for ensuring facility durability, life cycle performance and low maintainability. Furthermore, follow on contracts also rely on an effective quality management system for interface congruency. An effective Quality Management System (QMS) is also essential in mitigating risks and meeting schedule and budget performance objectives. For the past 15 years Central Puget Sound Regional Transit Authority’s Link Light Rail extension has successfully completed over 10 miles of twin bore tunneling and associated underground features including cross passages, deep sump structures and shafts. After the completion of each segment, lessons learned have successfully been implemented to improve the quality of delivered projects. This paper presents the Sound Transit QMS with regard to a number of project elements of tunnel construction projects, with specific focus on quality performance of slurry wall construction, TBM tunnel excavation assessment, segment production and segmental lining installation, and other associated construction features. A collaborated total QMS will be presented in this paper that will serve as a guide for successful implementation of Quality Assurance and Quality Control processes. INTRODUCTION Implementation of a robust Quality Management System reduces defects, errors and omissions, identifies and addresses nonconformance in a timely manner and increases stakeholder confidence in the project. In fact and effective QMS helps ensure that optimal project outcomes are realized both in terms of project delivery and life cycle performance. The two key components of QMS are quality control and quality assurance. Quality Control (QC) is the procedure implemented to achieve a certain level of quality and ensure that products, processes and services meet specific requirements. Quality Assurance (QA) activities are carried out to evaluate the effectiveness of the quality control measures and ensure that the QC process is working. A team obligation that recognizes that quality is built into every aspect of a project is the basic concept of a successful QMS."

Jan 1, 2016