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The paper describes the development leading to the bucket wheel excavator systems now used in the Latrobe Valley and refers in particular to the new S.E.C.V. dredgers Nos. 14 and 15 which will be employed in the Loy Yang open cut. The design concept and operating possibilities of these dredgers are described in detail with reference to the machine characteristics designed for the operating conditions in the Latrobe Valley. The design is compared with units of similar capacity in open cuts of other countries.

Jan 1, 1982

By Robert W. Shearman

An historical record of the history of iron-and steelmaking in the United States has long seemed a desirable project to many in The metallurgical Society of AIME. Over a period of five years, experts in their fields have been asked to put down on paper their knowledge. The series of historical articles has been published in JOURNAL OF METALS, beginning with A. B. Wilder's article in 1956, marking the first one hundred years of Bessemer Steelmaking. The Electric Furnace Committee honored the first half-century of the use of the electric arc furnace in America during their 1956 Conference, and S. B. Casey, Jr., wrote an appropriate article for JOURNAL OF METALS. The historical series was well underway. Articles soon followed on the history of the blast furnace, on the open hearth furnace, and on ferro-alloy manufacture. The final need was an authoritative article on coke ovens. The publication of the five-part article by C. S. Finney and John Mitchell this summer has concluded our series (but not the march of progress). We now present, between two covers, a comprehensive historical review, the work of 13 authors. We are hopeful that this book will receive a welcome among ironmakers and steelmakers. and that it will be a valuable reference for home or office library. We hope also that students will find the material helpful in their studies of this most important of American industries. Perhaps also, the historian of Americana will learn something new in searching through these pages. We are indebted to our authors who have spent much time on historical research, and to their companies who have supported their endeavors. We acknowledge the support of the National Open Hearth Steel Committee and of the Blast Furnace. Coke Oven, and Raw Materials Committee in jointly assuming the financial risks in publishing this book.

Jan 1, 1961

THE second award of the Saunders Gold Medal for "distinguished achievement in mining," of which the first was awarded last year to the late D. W. Brunton, has been made to Herbert Hoover. The main events of Mr. Hoover's life are so familiar to all through the numerous journal articles about him and his work, and the interesting biography written by Vernon Kellogg, that no attempt will be made here to touch on anything other than his achievements as a professional mining engineer, for which the award was made. He graduated in mining from Leland Stanford, Jr., University in 1895, but had served as an assistant to Dr. Branner on the Arkansas Geological Survey in 1893 and had also worked two sum-mers as an assistant to H. W. Turner and Waldemar Lind-gren on U. S. Geological Sur-vey work in the Sierra Nevada around Lake Tahoe, and on the American River. Immediately after graduation he got "a job" underground at Grass Valley, and soon rose to be night shift-boss. He then secured employment with the late Louis Janin and made such a good record as office and field assistant that he was soon placed in charge of a small mine at Carlisle, N. M. In 1897, Mr. Janin recom-mended him to Bewick, More-ing & Co., who were looking for an examining engineer for their staff in Australia. Two years were spent in hard work there which was done so creditably that his princi-pals held him and his judg-ment in the highest regard, and he came to the head of their local organization. Among the properties which he acquired for them was the Sons of Gwalia.

Jan 2, 1928

By R. Sharma

The heterogeneous distributions of nodule sizes, cover-ages and abundances and the variability of their burial und association with sediments and rock outcrops on the seafloor have emerged as crucial parameters in considering the exploitation potential of the manganese nodules in the central part of the Indian Ocean. Nodules with the long axis measuring from 20 and 40 mm (0.8 and 1.6 in.) account for nearly 60% to 70% of those evaluated from photographic and grab-sample data. In addition, 75% of the nodules (by weight) are between 20 and 60 mm (0.8 to 2.4 in.). The distribution of nodules with abundances ranging from 1 to 20 kg/m2 as well as coverages of 1 % to 90% on the seafloor are important considerations in demarcating the potential areas for nodule mining. The mining of areas with higher concentrations of nodules, such as along slopes associated with less sediment, would result in the enhanced recovery of nodules compared to areas with low nodule concentrations, such as in valleys and plains where thick sediment covers occur. The mining head will encounter substrates such as hard rock exposures, either with or without Fe-Mn encrustations, as well as soft sediment layers in the nodule fields. It must be able to collect buried nodules under sediment cover, and it must be able to negotiate uphill and downhill slopes in mining areas. Mapping prior to mining must delineate areas to he avoided and must define locations to be mined. The requirements suggest that the nodule collector must be a dynamic (active) system with sensors to detect areas of potential nodule concentrations, as well as features that are hazardous (or unfavorable) for mining operations.

Jan 1, 1999

By Samuel W. McNary

In August 1984 the U.S. Bureau of Mines conducted a study of the mineral resource development potential of the Badger Canyon-Antelope Creek area, within the Boulder-Pioneer wilderness study area, about 5 miles northeast of Ketchum, 10. The purpose of this study was to investigate in greater detail an area which was designated by the U.S. Geological Survey (USGS) and the Bureau as having a moderate mineral resource potential for zinc, molybdenum, lead, and silver, and a low potential for copper. One hundred twenty-eight soil samples were taken along a 6,2S0-ft traverse on the ridge separating Badger Canyon and Antelope Creek. 5 Five rock samples were collected from old prospect pits and mineralized outcrops. All samples were analyzed for gold. Silver, copper, lead, zinc, molybdenum, arsenic, antimony, vanadium, and mercury. The metal concentrations in the soil samples along the traverse are irregularly distributed. Samples collected near old prospect pits tend to be high in lead and zinc, undoubtedly a reflection of underlying galena-and sphalerite-bearing quartz veins. All of the copper and mercury values in the soils are less than the detection limit, as are most of the lead, molybdenum, and antimony values. Except for lead and zinc values, the metal concentrations in the rock samples are low. Galena and sphalerite were observed in quartz vein samples collected at the old prospects. The results of the study indicate that the galena-sphalerite-bearing quartz veins and veinlets are too narrow, widely-spaced, and low in metal values to be economic. Low concentrations of metals in the soil and rock samples, combined with the lack of major mining activity in the past, indicate that the area has a low likelihood for economic development.

Jan 1, 1986

By Waldemar Lindgren

At the time of the discovery of America the old world had a scant supply of the precious metals. Both the northern and the southern part of the new continent proved wonderfully rich in gold and silver and its treasures were eagerly looted; though the looting has lasted four centuries, the mines of its mountain chains are far from being exhausted. Even the later discoveries in Australasia and eastern Siberia could not rob the Western Hemisphere of its position as the greatest gold and silver producing region of the world, though finally the developments in a narrow and circumscribed area in South Africa wrested from the Americas their supremacy in the production of gold. Nevertheless the history of the two parts of the great western continent has been strikingly different. At first the Spaniards extracted vast treasures of silver from Mexico, Peru, and Bolivia, while Colombia arid some placer deposits in Peru yielded a smaller quantity of gold. A couple of centuries later, a stream of gold began to flow from Brazil, the silver production from the countries mentioned above continuing strong in the meanwhile. Later on, the yield of South America diminished, but to offset this there began a wonderful series of discoveries in North America. The gold fields of California astonished the world; and when the cream of these had been skimmed off there began a no less amazing development of the Central Cordilleran gold and silver districts, which soon made the United States the greatest producer of the precious metals. Aided by ever improving technique, extensive exploration, and a system of railroads, the yield was maintained and increased. Still later followed the discoveries of the gold fields of the arctic region and silenced those who had maintained that the zenith in gold production had passed. Recently the province of Ontario in eastern Canada

Jan 1, 1917

By Erwin S. Sperry

The presence of small amounts of tellurium in certain binds of copper, and its exceptionally deleterious* influence in producing red-shortness of this metal, led the author to conduct a few experiments on the influence of tellurium on the properties of brass. While these experiments were not intended to be exhaustive, they demonstrate that, as far as the rolling of brass is concerned, tellurium, unless it occurs in far greater amounts than exist in refined copper, cannot be called an injurious impurity. In comparatively large amounts it appears to impart cold-shortness to high-brass. Tellurium, the rare element that it is considered to be, has recently been extracted on a large scale from the slimes of an American electrolytic copper-works. They have, in attempts to discover some commercial use for it, sent it out promiscuously and gratuitously in quantities which would lead the young chemical student to fancy that a rare element exists only in name. Through the courtesy of Mr. R. L. Whitehead, of Baltimore, the author was able to obtain somewhat over 2 lbs.,? and use it in quantities which, at the market price, would be prohibitive. In order to add specific quantities of tellurium to brass, a rich alloy of copper and tellurium was previously made. The method was as follows, viz.: Nine and one-half lbs. of Lake copper were melted un-. der charcoal in a new plumbago crucible, and then pound of tellurium was added in small portions at a time. The mixture was stirred with a plumbago-stirrer and poured into

Jan 1, 1903

By Doug Anderson

Two quantities, Peak Particle Velocity (PPV) and Scaled Distance (SD), have controlled aspects of many blasting projects and operations for a long time. Vibration criteria typically use both PPV and SD because they are simple to measure, and simple to calculate. Their use in regulations worldwide is fairly ubiquitous, in efforts to limit damage to structures in the neighborhood of a blasting operation. PPV and SD are also used to determine likely blast damage effects in mining operations.

Jan 1, 2018

R. W. Raymond, New York City: From a study of Mr. Johnson's paper, I conclude that his apparatus is simple in construction and operation, and imitates in a revolving machine the movements of hand-shoveling. It does what a man would do in removing sand from the waste-water with a perforated shovel. I am sorry to say that I fear the present condition of the brown-ore mining industry in the East, as long as

Jan 1, 1899

Fluidised Bed Combustion technology has expanded since the first fluidised bed boiler steamed in 1974 with 58 companies currently supplying units. In Australia the market has been in small boilers and the goal of a limited attendance coal fired boiler has been achieved. On the world scene, the major incentive for development has been emission control with sulphur capture and low NOX. The potential of significant reduction in plant size is encouraging development of pressurised fluidised bed combustion.

Jan 1, 1987

R. W. Raymond, New York City: From a study of Mr. Johnson's paper, I conclude that his apparatus is simple in construction and operation, and imitates in a revolving machine the movements of hand-shoveling. It does what a man would do in removing sand from the waste-water with a perforated shovel. I am sorry to say that I fear the present condition of the brown-ore mining industry in the East, as long as

Jan 1, 1899

By Shining Z

The properties of coal or rock containing gas are very important both for studying coal and methane outburst mechanism and for controlling underground rock in mining. The rheological fracture properties of coal containing gas were studied to obtain its rheological fracture principle both in microscopic scale and in macroscopic scale. The application of this principle is successful in explaining coal and methane outburst mechanism and for putting forward a rheological hypothesis of coal and methane outburst.

Jan 1, 1992

By McQueen LB

The Water Board has been involved in the development and ipgrading of sewerage facilities in the Blue Mountains since 1980. In 1984 the Board prepared a report that dealt with the Blue Mountains Sewage Effluent Management study. Successive 3ovemments have been concerned about development in the 3lue Mountains and the effect this development is having on the luality of the streams flowing into the Blue Mountains National ?ark (presently up for World Heritage Listing).

Jan 1, 1993

By H. A. D. Kirsten

The structural competence of mesh- and fibre-reinforced shotcrete was investigated in two series of tests on full-scale panels. It was found that uniformly distributed loading was marginally less demanding than point loading, mesh reinforcement was superior to fibre reinforcement, Dramix fibre and Melt Extract fibre were similar in reinforcing characteristics, and 30 mm to 35 mm was an optimum fibre length. Furthermore, the consistency of the fibre content could not be assured on practical mining sites, and an average fibre content of about 1,5 per cent was the maximum that could be obtained for fibre lengths not exceeding 35 mm. Also, owing to its greater flexibility, shotcrete reinforced with diamond mesh was preferable to fibre-reinforced shotcrete in mining excavations subject to squeezing conditions. In view of the difficulties associated with assuring the consistency of the fibre content in mining applications, it appears that the sophisticated attributes of fibre-reinforced shotcrete can be effectively exploited only in civil-engineering applications in which quality assurance is subject to explicit contractual control. Load-deflection curves, together with measurements of compressive stresses in the surfaces of some of the panels, enabled the ultimate flexural strength of reinforced shotcrete to be rigorously formulated, and rigorous design procedures for shotcrete subject to bending and direct thrust to be developed. The application of the procedures is demonstrated in a practical design case in which the moments and thrusts in a tunnel lining are determined in a numerical analysis of the interaction between the lining, the surrounding rock, and the rock-reinforcing system.

Jan 1, 1992

By Lauri E. K. Holappa

The aim of the metallurgical process development is, nowadays, to search for the shortest, most economical, more environmentally friendly and sustainable route to convert raw materials to finished products. Recent progress in steelmaking processes ? BOF and EAF - has also motivated to search for more advanced casting technologies to shorten process route. Continuous casting, which became industrially feasible in the 1960s, is now a mainstream technology with over 90% share of the world steel casting. After the 1980s, the increase in steel production and consumption, particularly from automobile, construction and home appliances industries, required steel manufacturers to accelerate production with more concise procedures, so that near-net-shape casting took the trend of development in order to bypass and simplify the downstream processes, e.g. cold/hot rolling mill or extrusion mill, to directly obtain finished products with required geometries. Progress in flat and long products changed the industrial operation pattern, strengthened steel production efficiency, and formed the operation concepts of the integrated steelworks and mini-mills, respectively. Thin slab casting and strip casting have represented the most important progress and promise, in the recent years, of such innovations furthermore strengthening the production efficiency and, concurrently, coinciding with the demands of environmental protection and sustainability. This paper reviews the most recent progresses in near-net-shape casting and prospects the impacts to steel industries as well as the development trends of steel production, in general.

Jan 1, 2006

By Fabio Da Costa Garcia Filho

O uso de resíduos de vidro como aditivo mineral finamente moído, em substituição parcial de cimento e agregados é uma direção promissora para a reciclagem. Este trabalho teve como objetivo analisar a influência de resíduos do processo de corte de vidro em argamassa adesiva, como substituição parcial de cimento e agregado miúdo. O vidro em pó foi utilizado em percentuais de 10, 15 e 20% em peso em substituição ao cimento Portland e, em outro momento, em substituição ao miúdo agregado. Verificou-se que a substituição refletiu positivamente sobre a resistência à adesão da argamassa, com o aumento da temperatura de cura.

Oct 30, 2017

By Joseph R. Wojcik

Introduction Placer deposits account for one-half to two-thirds of the total gold produced worldwide. As many as 311 t (10 million oz) have been produced from some major districts. Several others are credited with 155 t (5 million oz). All the major districts and many lesser ones have similar characteristics. Consideration of these characteristics offers insight into the origin of gold in the deposit. Knowing the gold deposit's geologic history leads to useful conclusions in exploring for placer deposits and for deposits in consolidated areas. Placer Deposit Characteristics Table 1 lists 17 placer gold districts around the world and their characteristics. These include type and age of, mineralized source rocks, associated intrusive rocks, and age of intermediate sedimentary cycles. Although quartzite or sandstone occurs in the bedrock sequence in four of the 17 districts, slates, phyllites, or schists are present in all of the districts. Additionally, in all but three, the slates are pre-Mesozoic. And, in six of the remaining 14, the slates are Precambrian. Rocks intrusive into the slates are all of intermediate to acidic composition and are emplaced as stocks, dikes, or sills, rather than being batholithic in proportions. Intermediate interceptors have not been recognized in only three of the 17 districts. Data from China and Mongolia are inconclusive as to this characteristic. Black Shale Gold Higher than average gold values are found in modern sedimentary rocks in coarse granulites, conglomerates, sandstones, and gray-wackes. Not so predictably, higher than average gold values also occur in black shales and carbonaceous argillities. Li and Shokena (1974) found that, in the Proterozoic sedimentary and equivalent metamorphic rocks of the Enisei Ridge, carbonaceous and graphitic phyllites and schists were particularly enriched in gold. Korotayeva and Polikarpochkin (1969) reported gold content in organic rocks to be enriched up to 15 times more than the organic free shales and siltstones of the Nerchinsk Zavod region of eastern Transbaikal. Black shales can be gold interceptors as are rocks of the granulite facies. Gold occurs in shales in particulate, free form, in pyrite, adsorbed on clays, and precipitated on carbon. In copper-bearing shales of Poland's Fore-Sudetic monocline, Kucha (1973) reported gold present in organic compounds as well as in silver bearing minerals. Anoshin (1969) found a strong correlation between gold and the pelitic fraction of sediments in certain rocks of the Atlantic Ocean basin. Heavy metal absorption on clays results in agglomeration to the extent that the particles settle with the heavy mineral fraction in enriched strata. Piper and Graef (1974) think that gold in sediments on the flank of the East Pacific rise is of lithogenic origin. Crockett (1973), however, proposed a volcanogenic exhalative origin. A strong correlation between gold and volcanic activity exists in rocks of the Canadian Shield where tuffaceous sediments and porphyries are more frequently enriched in gold than rocks with no volcanic components. Volcanic rocks of intermediate to acidic composition are considered here to be the primary source of gold in black shales. Gold is concentrated in shales as detrital free grains with diameters less than 50 µm (270 mesh), as precipitates, and in pyrite or other sulfide minerals. This is the first step in the history of gold placer deposits. Grain Size Modification Gold, as free grains with diameters less than 50 µm (270 mesh), is too light to be concentrated hydraulically into placer deposits. Some process has increased the average size of the gold grains. Mobilization during regional metamorphism converts most of the gold into particulate grains or entrains it in microfractures in the sulfide minerals. With moderate folding, small, white, vitreous quartz veins develop. As deformation continues, larger, more conspicuous quartz veins are formed. The larger veins are folded and faulted and contain native gold as minute specks and flakes not visi-

Jan 11, 1984

By Claudine Guimarães Leite Cardoso

Em busca do aumento da produtividade em vergalhões é requerido o incremento de pesos das bobinas e velocidade no processo produtivo de laminação a frio do fio nervurado CA60 sendo notada a ocorrência de anomalias durante processamento de telas, a alteração de coloração na superfície do arame. Verificou-se a necessidade de um estudo para a caracterização do produto e modificação no processo decorrente das insistentes falhas nos processos posteriores durante a aplicação do fio prejudicando a produção esperada, assim como a ocorrência de sucata e redução de performance dos equipamentos. Com base na literatura, foram realizados ensaios para determinação de propriedades mecânicas e análise metalográfica cujos resultados se mostraram contrastantes nas amostras descrevendo comportamentos diferentes durante a produção do material. O projeto visa o entendimento do impacto gerado pelo aumento de velocidade de processamento minimizando as perdas de performance na trefilação por travamento de mancais de cassete e posteriores aplicações em ampliados.

Aug 16, 2017

By Hugo Egoavil, Michele D´Acquisto

El proyecto de construir un muro de concreto plástico (cut-off wall) y una cortina de impermeabilización mediante inyecciones de cemento respondió a la necesidad de realizar el recrecimiento del dique polishing pond, para permitir la expansión del depósito y la elevación de la corona de la presa de relaves de Antamina (a 4,165 msnm), tomando en consideración la disposición de un embalse de una capacidad volumétrica que satisfaga las condiciones de almacenamiento de la precipitación máxima probable. El sistema de impermeabilización de la cimentación de la presa consta de dos fases: 1) la construcción de una pantalla de concreto plástico de un ancho nominal de un metro y hasta 40 m de profundidad (se empotra un metro en roca) y 2) la creación de una cortina de impermeabilización en la parte central de la presa (por debajo de la pantalla plástica) y el plinto izquierdo, mediante inyecciones de cemento que han alcanzado los 50 m de profundidad mínima en roca fracturada.

Sep 30, 2018

By Marcelo Xavier Gonçalves, Rodrigo Jorge dos Santos Arruda, Sergio da Cunha Motta

Em busca de uma solução para a mitigação dos riscos aos quais os empregados da empresa Sepetiba Tecon S/A ficam expostos, redução dos custos, eliminação do consumo de madeira e da utilização do brometo de metila (substância que agride a camada de ozônio, utilizada no processo de tratamento da madeira para exportação), buscou-se inovar o processo de peação de bobinas com eixo horizontal e vertical até 13 toneladas, dando continuidade ao processo iniciado em 2017. Para isso, foi elaborado o projeto que substituiu toda a madeira utilizada na peação (travamento da carga) por cintas com filamentos de poliéster de alta tenacidade e polipropileno homopolímero, tornando o processo sustentável, seguro e mais eficiente.

Oct 1, 2019