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By AIME

DURING the happy and peaceful years between the Treaty of Versailles and the third New Deal, metallurgy became one of the most cosmopolitan of the sciences. Any metallurgist can name some twenty or thirty scientists whose work, in this country, in England, in Germany, or in France, Sweden, Italy, or Japan was as well known in other parts of the metal-producing and metal using world as it was locally, despite the fact that many of these men never left their native land. One of these metallurgical cosmopolites is Augustus Braun Kinzel, former Chairman of the Iron and Steel Division, A.I.M.E., and now a Director of the Institute. Gus Kinzel, however, is not only a cosmopolite by reputation; he is also a cosmopolite in fact. For many years he commuted at least twice a year between New York and the rest of the world; he is, therefore, not only an expert on the art and science of metallurgy but is equally expert in world travel and can expound with authority on the comparative quality and especially on the cuisine of the great prewar steamship lines; and being a true cosmopolite, he knows, as well as he knows the iron-chromium diagram, the best vintage years in the Gironde, Cote d'Or, and Saone-et-Loire departments in France and along the banks of the Moselle and Rhine in Germany.

Jan 1, 1946

By Xinhua Wang, Qiangqiang Wang, Yubin Li, Shusen Li, Lifeng Zhang

"Numerical simulation on the fluid flow in a Flow-Control Mold (FC-Mold) were performed. The motion of inclusions were calculated. With FC-Mold, the flow pattern and surface velocity become more symmetrical, and at higher casting speed the velocity of liquid steel in the top region of the mold was largely reduced with the highest velocity of the meniscus reducing from 0.65 mis to 0.4 mis, and the meniscus shape became flatter. With FC-Mold, more inclusions approached to the surface of the slab and the amount of inclusion in the center of mold became fewer. Larger inclusions were easier to remove, however, the EM filed of the FC-Mold could hardly improve the removal of inclusions from the molten steel.IntroductionElectromagnetic brake technology is an effective method to control the flow pattern within continuous casting mold, together with other casting parameters, nozzle design and mold geometry [1-5]. Due to the interaction between the applied magnetic flux and the conductive molten steel inside the mold cavity, a force is generated in the direction opposite to the jet flow, which can decelerate the high speed steel jet from the SEN ports. The potential benefits include fewer surface and internal defects, fewer inclusion especially at higher casting speed. However if used imperfectly, electromagnetic forces can have opposite effect [6]. Numerical models are the best tool to optimize electromagnetic flow control. In the current study, numerical simulation was performed to investigate the flow field in a continuous casting FC-Mold, and the effect of different operation parameters on the flow, surface level and velocity in FC-Mold were discussed."

Jan 1, 2013

By Cyril Stanley Smith

ARCHEOLOGISTS, by use of the terms Bronze Age and Iron Age, indicate that metals have in the past determined the character of civilization. The relatively simple discovery by a primitive metallurgist that the addition of tin to copper both facilitated the production of castings and increased the durability of the product enabled hunter, warrior, and housewife alike to do things never dreamed of before. Similarly, the smelting of iron and the discovery of hardening methods greatly changed the arts of peace and war. Discoveries of low-melting-point alloys for joining and for making household utensils, and perhaps the adornment of a feminine form by sparkling precious-metal jewelry, have at times changed the destiny of a country. Bronze cannon, the cast and wrought iron Watt engine, copper transmission lines, and aluminum alloy aircraft, are cases of particular metals making possible the realization of an improved engineering design. Perhaps of the greatest influence of all upon civilization was the development of type metal. The rapid increase in the rate of dissemination of knowledge dates from the day that the technique of the pewterer was utilized in making rapidly reproducible and accurately sized letters for printing. It was not movable type, but metal type that was important, for metal castings could be made of identically the same shape and size at an enormous rate, and possessed excellent inking and wearing characteristics.

Jan 1, 1946

By Euclid P. Worden

INTRODUCTION Today, conventional raise boring is an accepted method of development in underground mines and on major construction projects. Over the years that this technique, and its associated machines and tools, have been under development, many articles have been written on the subject. To a great extent, these papers have reported operating results of one or more specific projects or have been generalized reviews of state-of-the-art machines and tools. This paper is intended as a review of the technique from an operational standpoint. Conventional raise boring, as opposed to the related variants box hole drilling and underground blast hole drilling, is a two step process consisting of the pilot hole drilling and reaming cycles. This author has covered the subject of pilot hole drilling in another article (1) . A good review of the current machines and equipment has been presented by Monroe (2) and an overall review of this entire technology was published by E&MJ (3) and Mining Journal, April, 1983 (4) . The subject of the reaming cycle is presented here together with some of the technical aspects of how the drilling tools are intended to be used. OPERATIONS Bit Change After the pilot bit has broken through at the end of the pilot hole cycle, a changeover takes place at both the machine and

Jan 1, 1985

By J. Mikhael Erekson, Connie Campbell Brashear, Brent Meins

Christmas morning 2020, an IED in an RV was detonated along an evacuated section of downtown Nashville, Tennessee. The blast damaged over 40 buildings, including AT&T’s Main Central Office and caused internet and cell outages across 1,200 zip codes for three days including the airport and EMS services. Published investigations by the ATF and FBI were inconclusive in determining the explosive composition and size. Video captured a large fireball that may indicate a fuel-air-mixture explosion which would create lower peak pressures than high explosives, but longer pressure duration and significant impulsive loading. Blast pressures were amplified by reflections in the urban environment bordered by the 8-story AT&T building and a row of multi-story historic buildings. Some structures had little damage as they were shielded from the blast pressure by closer buildings, and seemingly far-field structures contained damage from the pressure wave after multiple reflections and propagation through porous parking garages. Damage to the reinforced concrete frame AT&T building included snapped masonry ties, cracking and spall to the closest column, and vertical displacement of the elevator, even with the brakes applied. The historic structures directly across the street from the blast partially collapsed. Initial damage included complete failures of unreinforced masonry façades, broken timber beams, and uplifted roofs. Secondary, progressive collapse took place over months as the brick walls and weakened historic mortar could not resist typical wind and environment loads. One of the close historic structures was renovated in the 1990’s and structural retrofits to comply with building codes were required. The addition of steel columns and façade tie-ins improved survivability and it remained standing with a high percentage of the front brick intact. Generally, the observed blast damage was related to a structural component’s mass and flexibility. Internal timber framing was unscathed, but many steel studs required replacement. Glazing damage was observed several blocks away and many roof membranes were punctured by falling debris. Secondary damage from broken sprinkler lines and loss of environmental control often led to more costly repairs than the initial blast pressure damage. The proliferation of bomb-making knowledge leads to hundreds of bombings each year in the US. Building risk considerations should include explosive threats along with other hazards. ASCE structural standards and design manuals have been published to address these risks and may be useful guides for building construction.

Feb 6, 2023

By Shemek Oginski, MARK C. JOHNSON

All Rights Reserved. Printed in the United States of America. Information contained in this work has been obtained by SME, Inc. from sources believed to be reliable. However, neither SME nor its authors guarantee the accuracy or completeness of any information published herein, and neither SME nor its authors shall be responsible for any errors, omissions, or damages arising out of use of this information. This work is published with the understanding that SME and its authors are supplying information but are not attempting to render engineering or other professional services. No part of this publication may be reproduced, stored in a retrieval system, or transmitted in any form or by any means, electronic, mechanical, photocopying, recording, or otherwise, without the prior written permission of the publisher. Any statement or views presented here are those of individual authors and are not necessarily those of the SME. The mention of trade names for commercial products does not imply the approval or endorsement of SME.

Dec 1, 2015

By R. C. FLEMING

MINING rock asphalt for use as a paving material is an industry which has grown with the spread of the good roads movement. "Mineral Industry During 1930" reports asphaltic pavements constructed, including maintenance and repair but excluding pavement constructed with road-oil, cut-back or emulsified asphalt, as grown from 23 million square yards in 1911 to a high of 144 million in 1927. In 1930 the same source reports 106 million square yards of such paving laid and, in that year, 664,871 tons of native rock asphalt were so utilized. Many states contain rock asphalt deposits of greater or less importance but in only a few places are the de¬posits being mined commercially. In the year cited Ken¬tucky produced 305,024 tons of bituminous sandstone, Texas 270,138 tons, mostly bituminous limestone, while Alabama, Oklahoma, California and Utah produced 89,709 tons of bituminous rock for road construction. In addition Utah produced 37,906 tons of the purer asphaltic products, gilsonite, wurtzilite and ozokerite, for other uses. Speaking generally, the rock asphalt is a sandstone or limestone naturally impregnated with asphalt to an extent that makes it an ideal road surfacing material without mixing or treatment other than crushing. The asphalt content of the commercial product runs 8 to 12 per cent.

Jan 1, 1933

By George Chung

"The Iron Ore Company of Canada's Carol Lake Project is Located near the western boundary of Labrador, 960 air kilometers northeast of Montreal (Figure 1).The Concentrator operation was started in 1962 with a capacity to produce 7 million tonnes of concentrate per year. The bulk of the concentrate was pelletized at a 6 million tonnes per year pelletizing plant completed in 1963. The remaining concentrate was sold in the international market. The concentrator was first expanded in 1966 to 10 million tonnes per year capacity with the pellet plant also expanded in 1967 to match the increase in concentrate production. In 1973, the concentrator was further expanded to gear with the increase in concentrate sales. In 1977, more than 40 million tonnes of crude ore was processed to produce in excess of 17.4 million tonnes of concentrate and 10.4 million tonnes of pellets."

Jan 1, 1980

By N. Aouad

Dump truck operators are exposed to whole-body vibration (WBV) levels that exceed the International Standard Organization (ISO) 2631-1. The WBV level measured by RMS acceleration value, for operator comfort, and long-term health and safety is under 0.315 m/s2 by these standards. However, fundamental research by Frimpong and Aouad (2009, 2012) and field experimental study by Kumar (1999) have shown that operators are exposed to extreme WBV levels exposing them to injuries and musculoskeletal diseases in the long-term. These extreme WBV values in the vertical direction are equal to 3.56 m/s2, 1.12 m/s2 and 0.87 m/s2 for the operator?s seat, lower-back and cervical regions, respectively. This paper will outline current research to solve these problems. Keywords: WBV, Truck Vibrations, MSC.ADAMS, Virtual Prototyping

Feb 27, 2013

By H Haas

H. HAAS, San Francisco, Cal. (communication to the Secretary?). -Fig. 1 plainly shows that the comparison of the steam-turbine and Diesel-engine plants was made on a basis of 6,000 kw. continuous operating load. The tabulation of costs for an 8,000-kw. load is merely done to show the relation of increased output on' the unit power costs. Both plants would sacrifice their reserve capacity, which is to insure continuous operation, if operated to generate 8,000 kw. continuously; unless Mr. Hawkins advocates the operation of one of the turbines at 33.33 per cent. overload, retaining the other as a standby, which, besides overtaxing the turbine, results in a great loss of efficiency. It would he well for Mr. Hawkins to qualify certain of his statements. Thus, under the caption "Diesel Engines, Selection of Units," he says that "two of the largest Diesel-engine builders take the position that, in the present state of the art, they would not attempt to put out units over 1,000 kw.;" he should qualify it by saving that "two of the largest American Diesel-engine builders take the position that, in the present state of the art in the United States, they would not attempt to put out units over 1,000 kw." The reason that American manufacturers restrict themselves at present to units of that size is to be found not so much in a lack of experience in building large units as in a lack of a sufficient, demand for them in the United States to justify the heavy capital outlay connected with the development of such engines. There are relatively few localities in the United States where fuel prices are as high as they are in the Southwest, and regions of high fuel prices are sparsely settled and have a very limited demand for power. Where low fuel prices obtain, steam turbines are active competitors of Diesel engines for large power plants, particularly when the station load factor is low. As most of the American manufacturers of Diesel engines work under license agreements with European manufacturers, which limit their market to the United States and its possessions and Canada, a further limitation is imposed upon them, leaving to European firms practically the entire world as a market.

Jan 5, 1917

By Ihsan Berk Tulu, Keith A. Heasley, Chris Mark

"The Analysis of Retreat l\.fining Pillar Stability (ARJ\1PS) and the Lal\.fodel programs have been used successfully in the U.S. for designing safe pillar recovery operations for many years. However, the recent Crandall Canyon l\.fine collapse showed that further research is required to improve the pillar design for recovery under deep cover. To this end, the National Institute for Occupational Safety and Health (NIOSH) and the West Virginia University (WVU) l\.fining Engineering Department have been working together to improve both the ARJ\1PS and the Lal\.fodel programs.This paper compares and analyzes the overburden loads calculated by ARJ\1PS 2002, the new ARJ\1PS 2010, and the Lal\.fodel program with regard to the retreat pillar line, the gob, and the barrier pillars. The analysis shows a number of distinct differences between the ARJ\1PS and Lal\.fodel loading distributions. Ultimately, the programs, with their distinctive load distributions, are used to analyze a database of 52 deep cover pillar retreat case studies, and the ability of each program to discriminate between successful and unsuccessful retreat pillar plans is evaluated.INTRODUCTIONThe Analysis of Retreat l\.fining Pillar Stability (ARJ\.f PS) and the Lal\.fodel programs have been used successfully in the U.S. for designing safe pillar recovery operations for many years. However, the recent Crandall Canyon l\.fine collapse showed that further research is required to improve the pillar design for recovery under deep cover.Pillar recovery accounts for less than 10% of the coal produced from underground coal mines; however, in the period between 1989 and 1996, it accounted for more than 25% of all ground fatalities (l\.fark et al., 2003). In the past 15 years, the safety of retreat mining operations has greatly improved. l\.fark (2009) explains three steps promoted by l\1SHA and NIOSH for safer pillar recovery:1) Global stability through proper pillar design2) Local stability through proper roof support3) Worker safety through proper section managementThe ARJ\1PS and Lal\.fodel (Heasley, 1998) programs have been playing an important role in guiding mine operators in designing pillars to ensure the global stability of a retreat panel."

Jan 1, 2010

By J. N. Van der Merwe

The paper provides an overview of subsidence research which was done by the Sasol Company in South Africa over a period of more than six years. The magnitudes of subsidence elements in South Africa are largely similar to those in the U.S.A. and Australia, as opposed to Europe. The research resulted in a subsidence prediction method with a new approach to the prediction of ground strain. The paper also describes the effects of subsidence on various commonly occurring surface structures such as roads, overland conveyor belts, pipe lines and power pylons. It is concluded that while most structures are not specifically designed to accommodate mining induced displacements, they can nontheless be undermined safely and economically with only minor precautions.

Jan 1, 1986

By Dennis A. Swyt

In current post-industrial America, U.S. manufacturing is undergoing major changes both in the technology of its production and in the size and composition of its workforce. At the same time that computers and robotics move the shop floor toward becoming the unmanned "factory of the future" [1], they increase the need within the overall production enterprise for new types of technicians and engineering professionals [2]. Based on previous works which examined, first, the evolution of the technology of manufacturing toward the flexibly-automated factory of the future and, second, the technical- professionalization of U.S. manufacturing sectors [1,3], this paper looks briefly at the workforce of the U.S. metals industry.

Jan 1, 1989

By T Leach, B Fulton, R Stewart

Gold mineralisation at Porgera is inferred to have been derived from a deep differentiated magmatic source which is capped by a series of (now tilted) inward dipping sills and stocks, which comprise the Porgera Intrusive Complex. An arc normal transfer structure provides a conduit, at tile intersection with an arc parallel structure, into which basic magma derived from tile deep melting of mantle material has been emplaced. Two phases of mineralisation display an association with late stage feldspar porphyry intrusives. Stage I carbonate-base metal-style gold mineralisation occurs as early quartz-sericite, then massive sulphide and late zoned Mn-Fe-Mg-Ca carbonate vein/breccias. Magmatic fluids derived from the deep magma source, are interpreted to have migrated along me margin of a feeder stock to the sills, and south to Waruwari. Stage II epithermal Au-Ag quartz-style gold mineralisation occurs as early fluidised breccias and carbonate veining, followed by zoned quartz-roscoelite-carbonate-gold vein/breccias, and late carbonate and/or sulphate open space infill. Magmatic fluids are interpreted to have utilised the same plumbing system as the late stage feldspar porphyry intrusive, and then migrated into the Roamane Fault which was dilated by; dextral rotation on elements of the transfer structure, normal faulting, and refraction around the competent footwall hornblende diorite. Bonanza gold is localised in a jog in the Roamane Fault, hangingwall splits and at intersections with cross structures. Bulk low grade Stage I gold has been deposited by the mixing of magmatic fluids with cool gas condensate waters, whereas high grade Stage II gold mineralisation resulted from the rapid quenching of mineralised magmatic fluids by oxygenated groundwaters.

Jan 1, 1995

By M. H. Attia

The concept of sustainable development has been evolved into a working framework for sustainable manufacturing, in which the environmental requirements are introduced into product development at the design stage. This keynote paper is discussing a number of issues pertaining to the impact of manufacturing on the environment. The conflicting requirements of sustainable development, sustainable manufacturing (SM) and economical growth are presented in the light of successful case studies that were able to convert conflicts into opportunities. Integration of SM into the product life cycle is also presented. A number of concepts that are related to Ecoefficiency, e.g., inverse manufacturing, demanufacturing and re-manufacturing are also discussed. The paper underlines the fact that the positive impact of this new philosophy is equally applicable and beneficial to both; developed and developing countries. The paper concludes with an overview of Global trends in environmentally benign manufacturing (EBM); e.g., product-take back and emerging material and processing technologies. The state-of-the-art approach to Life Cycle Impact Assessment and integration of design for the environment DfE principles are demonstrated through some case study.

Jan 1, 2006

By J. L. Christie, R. H. Leach

SO much has been written recently about the use of silver to replace scarce metals that certain facts about silver and its uses should be of interest. Figures for the production and use of silver, taken from the Handy & Harman annual reviews of the silver market, are given in Table 1. It will be seen that the rate of production has remained fairly constant and has been affected in recent years by the production of base metals, of which silver is a by-product. In each of the years 1937, 1938, and 1939, the U.S. Government acquisitions alone exceeded the entire world production, the difference, of course, being made up by imports of previously accumulated stocks. In 1940 and 1941 the U. S. Government acquisitions plus the United States and Canadian uses in the arts and industries exceeded the Western Hemisphere production. The U.S. Government pays a premium price for silver newly mined in the United States, at present 71.11c. compared with the price of 35'/8c. for foreign silver, with the result that the current U. S. production is not used commercially for the arts and industries. At the time this is written (June 1942) there is much uncertainty as to the future effect of this situation.

Jan 1, 1942

By W. F. Boericke

WORLD production of silver in 1929 totaled 256 million ounces. In 1928 production was 258 million ounces, and in 1927, 254 million ounces. With an actual decrease in the amount of silver produced last year, as compared with 1928, and an increase over 1927 of less than one per cent, obviously there has been no overproduction of the metal in the popular sense. But the price of silver tells a different story. For 1927, the average quotation was 56.37 cents; it was 58.17 in 1928, and 53.0 in 1929. During the last year it reached a high point of 57 cents in January, and fell steadily, without interruption to the downward trend, to a low of 47 cents in December. Since then it has dropped to an all time low of 43 cents on February 6.

Jan 1, 1930

By Thornton L. Neathery

Vertical magnetic surveys have been made over about 3, 150 miles of the crystalline area of east-central Alabama. A contour map (100-gamma interval) showing regional magnetic anomalies has been prepared (scale 1:250,000) from data points located at quarter-mile intervals on all public roads. Small one- and two-station anomalies were eliminated, leaving only areally extensive anomaly features associated with regional geology. The regional gradient was "filtered" from the basic data and the resulting magnetic configuration compared to the regional geology. Regional lines of vertical magnetic intensity trend northeast and follow the structural framework of the area. Correlations can be made between a large number of geologic and magnetic features. The strongest regional anomalies are associated with the Goat Rock, Bartletts Ferry, Towaliga, and Brevard fault structures. The Inner Piedmont area is characterized by a broad regional high. The magnetic values of the northern Alabama Piedmont grades gently northwestward, disrupted occasionally by elongate highs and lows associated with amphibolites or granites. Scattered throughout the Piedmont are anomalous areas of high magnetic intensity; some are related to magnetic-bearing rocks, and some Indicate possible mineralization. Most of the anomalies have not been evaluated,

Jan 1, 1972

By Victor Romero, Steve Redmond

All Rights Reserved. Printed in the United States of America. Information contained in this work has been obtained by SME, Inc. from sources believed to be reliable. However, neither SME nor its authors guarantee the accuracy or completeness of any information published herein, and neither SME nor its authors shall be responsible for any errors, omissions, or damages arising out of use of this information. This work is published with the understanding that SME and its authors are supplying information but are not attempting to render engineering or other professional services. No part of this publication may be reproduced, stored in a retrieval system, or transmitted in any form or by any means, electronic, mechanical, photocopying, recording, or otherwise, without the prior written permission of the publisher. Any statement or views presented here are those of individual authors and are not necessarily those of the SME. The mention of trade names for commercial products does not imply the approval or endorsement of SME.

Dec 1, 2011

Studies were carried out to examine the effect of introducing varying levels of a pisolitic limonite (Yandi) into an Australian iron ore blend. Compared with other ores in the blend Yandi is more porous. This structure is found to have a considerable effect on the sintering behaviour of the blends. Pilot-scale sintering studies and plant trials showed that sinter plant productivity, sinter reducibility and the low-temperature reduction degradation index altered significantly when the level of Yandi in the ore blend exceeded 15 wt%. The improvement in the reducibility is thought to be a direct result of increased porosity in the sinter and the presence of highly reducible pseudo-relict haematite. Plant trials have also shown that operational changes could be made to the sinter plant to avoid potential deterioration of productivity

Dec 1, 1991