Search Documents

By Frank Firmstone

IN the summer of 1881 we were forced to break up and remove the large mass of iron which had accumulated under No. 2 furnace at Glendon, in order to prepare the foundations of the new furnace which has taken its place. We used "Atlas" powder, drilling the holes with a pair of Rand drills. These worked very well when the iron was at all uniform in hardness; but this was not often the case; and it frequently happened that the holes were hopelessly blocked when but little over a foot deep. Good tamping became, therefore very important. The common method of tamping is certainly very dangerous when there is a percussion cap in the hole, and has, no doubt, caused many of the accidents attributed directly to high explosives. We found an excellent and safe method by using plaster of Paris, mixed to the proper consistency and ponred into the holes as soon as they were loaded. Clean dry sand was mixed with the plaster to reduce the quantity needed. With proper attention the tamping would set in a few minutes, and little or no more time was required than for tamping in the ordinary way. We used a "magneto" machine (Laflin and Rand) to fire the holes; and an additiollal advantage in the plan was that any risk of cutting the exploder-wires in tamping was avoided. We found it worth while to load holes not over 13 inches deep in a block 3 or 4 feet thick since the bottom of the hole was enlarged by each shot so that the next time it could be loaded more heavily, and three or four shots in this way often did as much good as a new hole twice the depth, to drill which might have taken ten or twelve hours. The rise in temperature when boiled plaster solidifies is not sufficient to ignite the exploders, as we found by repeated trials before using it in a loaded hole.

Jan 1, 1884

By T. Sterry Hunt

Jan 1, 1884

By J. S. Harris

AS a result of the study of social problems to which so much thought has been given in this country and Europe in the last half century, many employers of labor have come to think that some provision should be made for their workingmen in case of injury. There has been a growing tendency so to administer the laws governing industrial pursuits in these countries as to add self-interest on the part of capitalists, to the plea urged by humanity, that every possible care should be taken to guard the workers from accident; but as no care can guarantee immunity, there is a necessity to supplement these precautions by some method of providing pecuniary aid that shall be available when disabling accidents do occur. It was once a favorite idea of theorists on political economy, that in the ideal state of society every man should take care of himself, and that the less care or control there was assumed by any man over others' private affairs, the better; but this gospel of selfishness has had its day, and it is now generally recognized that in the existing state of affairs the stronger and richer cannot escape the duty of being to some extent, the keepers of their less fortunate brethren ; and, on the other hand, that an assumption of care for them involving to some extent an exercise of authority, is not a thing to he necessarily and always resisted. Out of these convictions, many efforts for the amelioration of the condition of workingmen have grown—which or one result have produced various plans which combine the con-

Jan 1, 1884

By W. P. Shinn

In a paper contributed by W. A. Goodyear, M.E., on "Water Gas as Fuel," read at the Boston Meeting, February, 1883,* the following statenlent was made: "The latest experiments on a scale of some magnitude in our citier, in the way of heating buildings and furnishing power for manufacturing purposes, have been by the distribution of high-presslire steam through pipes laid in the streets. Hilt these experiments (1) have not hitherto been very successful; and when we consider the high cost and (2) the great and unavoidable loss of heat and power, which always accompany the conveyance of high-pressnre steam to any considerable distance in pipes, to say nothing of (3) certain practical difficulties in the management of the pipes themselves, (4) it is evident that all such methods must eventually disappear before a system which can furnish a cheap gas of great heating power, easily distributed wherever wanted, without requiring pipes to stand pressures of 50 to 75 pounds per square inch, and (5) without keeping the whole mass of ground in the streets through which it passes hot, gratis, for a distance of ten or fifteen feet, in all directions around the pipes!' For the purpose of controverting Mr. Goodyear's statements in regard to steam-distribution in cities, I hare numbered the points made in his indictment, my principal object being, not a professional discussion of the technical and theoretical merits of steam vs. watergas, but a simple statement of facts, in regard to the present state of the street system of steam distribntion. Taking Mr. Goodyear's points in their order: 1. Concerning what he terms " These experiments," saying that they " have not hitherto been very successful," I propose to show, that the problem of stearn-distribution has passed beyond the experimental stage, and that its practical solution is highly successful. This will be shown by the facts hereinafter fully set forth. 2. "The great and unavoidable loss of heat and power whicn always accompany the conveyance of high-pressure steam to any con-

Jan 1, 1884

By W. L. Dudley

It is my desire to call attention to a new industry which was started about four years ago, through the discovery by Mr. John Holland, a resident of this city, of the methods employed in working the metal iridium. This metal has been known since the year 1803, having been discovered by Smithson Tennant while investigating the metallic residue which remained when platinum ores were dissolved in aqua regia. The metal is classed among the rare metals, as it is not found in large quantities, although it is quite widely distributed geographically. It is found in California, Oregon, Russia, East India, Borneo, South America, Canada, Australia, and in certain parts of France, Germany, and Spain. The principal sources of supply of the metal are Russia and California; it is nearly always found with either platinum or gold, is extracted from those ores as a by-product, and is always found in small grains or fine powder, the largest pieces being about the size of a grain of rice. In nature it is generally alloyed with other metals, and the two metals with which it is most commonly alloyed are platinum and osmium; the platinum alloy is called platin-iridium, and the osmium alloy osmiridium, or iridosmine. The grains of platin-iridium are

Jan 1, 1884

By R. W. Raymond

Since the foregoing paper (see p. 387) was printed, I have received the decision of Judge William E. Church, of the first District Court of Dakotah, in the case of Michael Duggan et al. v. John H. and Frank J. Dnvey (Silva Terra—Sitting Bull case), published in full in the Black Hills Weekly Pioneer of August 9th, 1584. The journal mentioned gives also several interlocutory decisions rendered in earlier stages of the case; but I shall quote here only so much of the final decision as bears upon the .construction of the Revised Statutes concerning the apex, the end-lines, and the extra-lateral mining right, together with a sufficient statement of the facts of the case to explain the scope of the decision. " This is an action in equity, brought in the first instance to restrain a threatened trespass by the defendants upon certain mining property in the possession of the plaintiffs, known as the ' Silver Terra' claim ; the allegation being that the defendants were about to enter, through underground workings, the ground of the plaintiffs, and remove therefrom valuable bodies of silver ore. " The answer of the defendants, admitting the acts constituting the alleged threatened trespass, further averred that they had, in fact, at the time complained of, reached and passed, in their underground workings, throngh and beyond the vertical side-line of the Silver Terra claim, and therenpon justified the acts complained of, and claimed the right to pursue their workings into and through the Silver Terra ground, by virtue of their alleged proprietorship of a vein, lode, or ledge of rock in place, hearing silver, having its top or apex within the lines of a certain other mining claim called the ' Sitting Bull,' of which they claim to be the owners, which vein, lode, or ledge extended in a continnons body of mineral-bearing rock from such top or apex to the ground in controversy, and constituted the body of ore in dispute; and that it was in the pursuit of this vein, lode, or ledge in its downward course that they had passed beyond the vertical side-lines of the Sitting Bull claim, and for some hundreds of feet beyond, into the ,ground in controversy " Subsequently, a supplemental complaint was filed, setting up the entry into plaintiffs' ground by the defendants, and their claim of right to do so, and asking fnrther relief by a decree restraining the assertion of such claim, and quieting the title of plaintiffs. "The case was tried before the court without a jnry..... " Custer hill, upon which these claims are located, is situated in the village of Galena, in Bare Butte mining district, in this county. The village lies at the base of the western slope of the hill, which presents a lateral face from south to north

Jan 1, 1884

By W. H. Adams

Virginia, a store-house of metals, is more and more a surprise to the present generation. With her enormous available mineral wealth, worked upon steadily for over a century, exploited SUEciently to demonstrate beyond question costs and values, reported upon by our most eminent scientists, written up by thoroughly earnest correspondents, we yet find her little understood by capitalists or practical men, and until very lately overlooked by the advanceguard of pioneers in metallurgy, whose restless energy conquered the wilderness of Northern Michigan years ago, and has written a new and startling history for almost impenetrable Western territories. The world is learning through the mouths of giant furnaces lately put in blast at Lowmoor, Goshen, and Roanoke, more of this wondcrful State. It is becoming plain that nearer home, amid all the surroundings of civilization, under an equable climate and with the advantage of a minimum cost for fuel and labor, there are stores of mineral, varied in character and deposited over a wide area, which exceed all ordinary calcnlations. Principal among these minerals, iron ores have been, and will probably continue to be, the leading product and the source of greatest revenue. My attention has been called during the past year to one particular section of the iron-belt, where for forty years charcoal-furnaces were successfully operated, the ores being mined in open pits, as can so frequently be seen from the Connecticut line southward into Georgia. There is, however, a significant peculiarity in the character of these deposits of Louisa county warranting special mention, as it is thought that nowhere on the earth's surface, within so moderate a distance of tidewater, can their like be fouad. Probably half a million tons of lump and wash-material have been taken from pits

Jan 1, 1884

By J. P. Kimball

INCIDENTAL to a description of the hytlrographical basin of the Quemahoning in Somerset county, Pa., as a coal-field, I have, without a personal survey of the whole county, taken the pains to collate a synopsis of' leading facts, so car as available, relating to its coal resources. This is here presented, in view of an interest in the subject, growing out of a nearly central traverse of the county, in common with the southern tier of counties of the State, west of Blue mountain, by a new trunk line of railway—the South Pennsylvania. The political east-and-west boundaries of Somerset county, Pa., following the bold topography of Allegheny mountain and Laurel hill, are in common with the east-and-west boundaries of the First Bituminous Coal-basin formed by these ridges respectively, except the southeastern townships which lie on the eastern slope of Allegheny mountain. The nearly parallel anticlinals of Negro mountain and the so-called Viaduct axis stratigraphically divide the basin into three sub-basins, which, in order from east to west, are known as follows, viz. : I. Berlin-Salisbury (Eustern) Sub-basin : Between Allegheny mountain and Negro mountain, embracing the Berlin section of Barren coal-measures, the Salisbury section of Upper Productive coal-measures, and the Meyersdale and Garrett sections of Lower Productive coal-measures. 11. Somerset (Middle) Sub-basin: Between Kegro mauntain and the Viaduct axis, so called from the viaduct on the Conemaugh river, which there crosses it; embracing the section of Lower Productive measures of Mineral Point and Casselman on Castlenlan river, and of Somerset. 111. Johnstown- Confluence (Western) Sub-basin: Between the Viaduct stratigraphical sub-axis (which is less strongly marked topograpically in Somerset county as a ridge than in Cambria county), and the Laurel Hill graud axis. The synclinal of this sub-basin is crossed by tile Conemaugh near Johnstown, and by the Castleman

Jan 1, 1884

By A. Springer

Chemists, physicists and others, whose occupations necessitate the use of fine scales, have heretofore regretted their inability to obtain any which would remain uniformly accurate. The difference between the theoretical and the actual results obtained in the ordinary balance (provided the pivot-distances are exact) is mainly due to the frictional resistance between the knifeedges and their bearings. This frictional resistance, although reduced to a minimum in the finest scales when new, constantly increases, thereby decreasing the sensitiveness proportionately. When examined under the microscope, neither the surface of the knife-edge nor that of' its hearings ever appears perfectly smooth. Soft kunife-edges are easily blunted, whereas hard ones are brittle and liable to crumble under the effects of over-load or shock. Prof. Frederick A. Roeder for many years attempted to discover some means by ,which the knife-edge could be replaced with some device free from the above-mentioned objections. His experiments convinced him that a torsion-joint was best suited for that purpose. After he had communicated his conclusion to me, we jointly developed the system to its present form. A torsion-wire had been used for the centre of rotation, prior to Prof. Roeder's invention, but it was found impossible to replace the terminal knife-edges with torsion-joints.

Jan 1, 1884

By Herman Halupka

El presente texto describe los progresos alcanzados durante los cinco años de operación de dos hornos en la fabricación de pelets que desarrolló la mina Marcona a través del sistema de parrilla deslizante, patente Dravo-Lurg. Asimismo, se señala os procesos empleados para fabricar pelets como: molienda y concentración, filtración, bolas verdes, endurecimiento, y la preparación del concentrado de mineral de hierro para ser peletizado.

Jul 1, 1969

By E. L. Fisk

First discovered and claimed in 1929, the Cordero cinnabar deposit lies 11 road miles southwest of McDermitt, Nev., near the Nevada-Oregon boundary. The name "Cordero" means "little lamb" in the Basque language and is symbolic of the fact that the first ore specimen was found during the lambing season. The Bradley Mining Co. held the property for several years during the early thirties, but it was not until 1939 that Cordero Mining Co., a subsidiary of Sun Oil Co., entered the picture. The company, then known as Horse Heaven Mines, Inc. conducted preliminary work in 1940 which proved enough near-surface ore to warrant the construction of a mill during the following year. By 1943, Cordero was being rapidly depleted when deeper churn drilling intersected the large underground orebody that is still being mined today.

Jan 11, 1961

By Luis Quevedo

En el proyecto Pangui, localizado al sureste del Ecuador de las provincias de Morona Santiago y Zamora Chinchipe, se descubrió un cinturón de pórfidos de cobre con tendencia N-S y un skarn de cobre. Esta zona se localiza entre el flanco occidental de la Cordillera del Cóndor y las estribaciones orientales de la cordillera real cercanas al borde limítrofe con el Perú. La mayor parte del área está cubierta por selva y las pendientes son abruptas. En la zona no hay una buena infraestructura de carreteras. En este sentido, el presente texto describe las actividades de Gencor y Billiton durante 6 años, así como los resultados de un año de actividades de Corriente/Lowell en los proyectos Warintza, Mirador y Panantza.

Apr 24, 2001

By Diego Pacheco Wermuth

O presente trabalho apresenta os resultados do estudo e aproveitamento de cinzas leves da queima de carvão mineral em termelétrica, como reforço para o Compósito de Matriz Metálica de cobre. Foram estudados diferentes percentuais de cinzas leves como reforço para o cobre, sendo misturados estes pós através de misturador “duplo v”, compactando os pós em diferentes pressões e sinterizando os corpos de prova obtidos pela compactação. A amostra sinterizada que apresentou a maior dureza entre todos os corpos de prova sinterizados, atingindo 89 HV, foi utilizada como base para a formulação e obtenção de novos corpos de prova, que foram estudados sob condições de moagem dos pós por moinho de bolas e moagem de alta energia. A fabricação do compósito seguiu os padrões industriais do processo de Metalurgia do Pó, como a mistura e moagem dos pós, compactação dos pós e sinterização em atmosfera controlada. Foi realizado o estudo das propriedades mecânicas do compósito formado por cobre e cinzas leves, que comprovou o aumento da dureza para 122 HV. Este trabalho proporciona uma nova aplicação para as cinzas leves, utilizando estes resíduos de usinas termoelétricas como matéria prima para reforço mecânico na composição de peças à base de cobre na indústria metalúrgica.

Aug 17, 2017

By Bruno Veiga Fontana

O uso do nitrogênio como gás de injeção através de plug poroso no forno panela pode ser importante do ponto de vista econômico, no entanto pode provocar pick-up excessivo de nitrogênio caso seja realizado de forma inadequada. No presente trabalho, são apresentados os resultados de testes de injeção de nitrogênio e nitrogênio seguido de argônio em aços para produtos longos. Visando compreender os processos de absorção e sua cinética, um modelo cinético é formulado e ajustado aos dados experimentais. O modelo cinético clássico descreve bem os resultados experimentais e permite o uso para previsões do efeito da injeção de nitrogênio sobre o teor de nitrogênio no aço. Observa-se que a cinética de absorção é controlada pela agitação da panela e pela presença de elementos tenso-ativos, notadamente o oxigênio, como esperado, de acordo com os modelos clássicos do fenômeno. A técnica da injeção de nitrogênio seguida de argônio é bem-sucedida economicamente e o modelo permite a previsão e o controle da absorção de nitrogênio pelo aço.

Aug 17, 2017

By Mery Cecilia Gómez Marroquin

Um importante problema das indústrias de fabricação de aço, decorrentes do uso de sucata de aço, é o de recuperação dos metais contidos nos pós e lamas produzidos nos fornos elétricos a arco (FEA) e nos conversores LD/FOB. Cerca de 10 a 20 kg de pó por tonelada de aço são gerados nos Fornos Elétricos a Arco, considerados resíduos perigosos pelos órgãos fiscalizadores (classe ? - material perigoso/NBR). Vários processos, utilizando tecnologias distintas (pirometalúrgicas e hidrometalúrgicas), buscam a recuperação técnico-econômica principalmente do Fe e do Zn, contidos nesses resíduos. Neste contexto, estudos básicos sobre a redução carbotérmica dos constituintes dos pós de aciaria, permanecem sob estudo. O presente trabalho foca a redução de ferrita de zinco gerada em laboratório, principal composto de zinco presente nos pós de aciaria, por meio de CO puro e misturas CO-CO2. A fenomenologia da redução considera a decomposição prévia seguida de reduções simultâneas, bem como as significativas influencias da temperatura, do tempo e do teor de CO.

Aug 8, 2018

By Camila Magalhães Gonçalves

O aço inoxidável ferrítico tipo 430 estabilizado com Nb, com e sem recozimento após laminação a quente, foi laminado a frio e submetido a recozimentos isotérmicos em temperaturas de 650, 700, 750 e 800°C por tempos variando entre 10 e 86400 s. A quantificação da fração recristalizada foi realizada pelo modelo de JMAK e pela microdureza ao longo do recozimento. A evolução da textura foi analisada via técnica de EBSD. Ocorreu o refino de grão após a recristalização, resultando em um tamanho médio de 8 mm. A temperatura de recristalização aconteceu a 750°C e esta teve maior efeito na recristalização que o tempo. Os expoentes de Avrami se situaram entre 0.8 e 1.2, significando nucleação em contorno de grão. A taxa de nucleação e de crescimento do grão diminuiu continuamente com o tempo. Em relação à textura, observou-se um aumento da intensidade das componentes (111)[121] e (111)[011] da fibra g e diminuição na intensidade da fibra a de deformação. Um modelo de cinética de recristalização do aço tipo 430 estabilizado com nióbio que leva em conta os processos de nucleação e crescimento foi obtido.

Jan 16, 2018

Os mais importantes processos de redução de minério de ferro em fornos de cuba convivem, com maior ou menor intensidade, o problema de precipitação de carbono no interior de seus reatores. Para melhor conhecer os efeitos dos parâmetros operacionais desses processos sobre as cinéticas simultâneas de redução das pelotas de minério de ferro e de precipitação de carbono, foi definido um programa cooperativo entre a Samarco e o Grupo de Siderurgia da PUC-Rio. O presente trabalho é a parte 1 deste programa, que analisou o comportamento de pelotas RD nas temperaturas de 500, 700 e 900 °C, vazões de 60 e 90 NL/min e pressões de 1,2 e 2,5 atm, quando reagiram com os gases de topo e sopro típicos das regiões superiores (Zona de Redução-ZR) dos fornos de produção de ferro esponja (DRI). O tratamento dos resultados obtidos nos testes programados pelo método estatístico fatorial, permitiu identificar as cinéticas concorrentes e propor um modelo global baseado no principio da superposição. Finalmente, utilizando as curvas “Grau de Reação Global-GR versus tempo”, mostrou correlações plenamente compatíveis com os dados experimentais levantados e plena viabilidade de aplicação a outros processos de produção de ferro primário.

Aug 1, 2018

By André de Albuquerque Vicente

O estudo detalhado das cinéticas de oxidação a altas temperaturas ao ar permitiu o cálculo da energia de ativação aparente do processo de oxidação de um aço inoxidável austenítico laminado do tipo 22.12. Utilizou-se o aço inoxidável austenítico microligado ao cério (253 MA®) que é um aço projetado para trabalhos a altas temperaturas. Observou-se cinéticas de oxidação parabólicas em todas as temperaturas estudadas: 800, 900, 1000 e 1100 ?C. Os Kps encontrados neste trabalho reforçam a tese de que ocorra a formação de películas protetoras de Cr2O3 e SiO2, o que reforça a hipótese que as mesmas tenham sido efetivamente formadas após os estágios iniciais de oxidação.

Oct 30, 2017

By Garry Johansen, Andrew McCallum, Sandy Gray, Gary Patrick, Jennifer Abols

"The authors challenge the traditional thinking that whole ore cyanidation followed by Carbon in Pulp (CIP) or Carbon in Leach (CIL) should be applied as a standard process in the majority of gold processing flowsheets. The concept of whole ore leaching by using cyanide can result in unnecessary environmental and capital risk. Alternative, currently available technologies can be used to provide the desired level of gold recovery at a much lower installed cost and less impact on the environment. Gravity concentration, alone or in conjunction with flotation, can produce a gold bearing concentrate that can then be fed directly to a batch or continuous intensive cyanidation unit.The InLine Leach Reactor (ILR) is an intensive cyanidation unit developed by Gekko Systems of Australia. Advantages of this technology include significantly reduced capital outlays for greenfield plants or plant upgrades and increased investor returns. Reduction of onsite cyanide and carbon inventories improves plant safety, materials handling and site security. By using direct electrowinning to treat the gold bearing solutions produced by the ILR, the need for a conventional carbon stripping circuit is removed. Potential also exists to increase grind size – saving energy, further reducing capital and operating costs and decreasing the environmental impact of a mill. Detoxification of cyanide before the release of solution to the tailings dam can minimise tailings disposal and containment requirements.When used in the right application the proposed process will have little or no impact on gold recovery and may actually increase recovery for complex ores. Areas applicable to this type of treatment include: plants in environmentally sensitive regions, lower tonnage higher grade deposits, coarse gold deposits, and preg robbing ores - some of which may not currently be economically feasible using standard processes and flowsheets. We have provided three examples of such projects, where an alternative to whole ore leach and CIP or CIL has delivered these benefits."

Jan 1, 2003

By M. J. Virnig, Christopher A. Fleming

THE CIP PROCESS "IN THE RIGHT PLACE AT THE RIGHT TIME? After its tentative introduction to the precious metals mining industry in the earlier part of this century, the carbon in pulp (CIP) process has now come of age, and is the process of choice on all new gold mills. Well over 50 percent of all gold that is mined each year is recovered by adsorption on activated carbon, and the percentage will increase in the years ahead, when old mills using Merrill Crowe technology come to the end of their lives, and as the proportion of world gold production from low-grade resources increases. The pioneering process development work in this field, which was mainly concerned with carbon elution, was carried out by Zadra and his colleagues at the United States Bureau of Mines in the early 1950's (Zadra et al., 1950, 1952), and led to the commissioning of the first large-scale, industrial CIP plant, at the Homestake Mine in South Dakota, in 1973 (Hall et al., 1974). From there, the process spread rapidly, firstly in South Africa in the late 1970's. and then throughout the rest of the gold producing world in the 1980's. There were several factors that led to the meteoric (by gold industry standards) acceptance and successful implementation of this new technology into gold processing operations worldwide. Firstly, and perhaps most fortuitously, the development of the technology closely paralleled the 1968 release of the gold price from the rigid constraints of the $35/oz. gold standard. With the value of the metal allowed, for the first time in modern history, to fluctuate in response to free market supply and demand forces, the gold industry witnessed an unprecedented boom as the price of their commodity increased ten-fold in a remarkably short period of time. This had several important spin-offs as far as new process developments were concerned: The profits realized by established gold-mining companies increased enormously and, consequently, there was more to spend on research and development and exploration for new deposits.

Jan 1, 1993