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By John F. Wiggert

DURING the early years of Homestake operations, shaft signaling from the cage tenders to the hoisting engineers was done by mechanical means. Small steel cables or jointed steel rods were suspended in the shaft compartments and counterbalanced with weights or springs. These cables or rod strings were connected to the mechanically operated gongs at the engineers' stations by means of bell cranks and steel wires. The system was simple and economical and served the purpose well until the mine reached a depth of 1000 ft., then the system became slow and cumbersome and required a considerable amount of muscular effort to operate it with much speed, because of the inertia of the heavy moving parts. The mechanical signaling was superseded by a simple electrical system consisting of a single pair of wires in steel conduit for each shaft compartment. In the shaft at each station a pull switch was connected to the wires. The switches were operated by means of bell cords, which extended from station to station. This electrical system was a great improvement over the mechanical one, but it had one serious drawback, which also applied to the older system; namely, the engineer did not know where a signal originated. Later on this signaling was improved to overcome this drawback, and to give the engineer a positive indication of a signal's origin. In this system a separate return wire from each pull switch is carried to an annunciator at the engineer's station, where it indicates the signal's origin. While the annunciator system used by Homestake is very safe and reliable, it has the inherent drawback of all wire-connected systems in that it is impossible to send a signal from a moving cage. A number of years ago Homestake became interested in the possibility of using some sort of radio transmission for shaft signaling. The company did much experimental work with purely radio signal transmission, but no practical way was discovered to use radio transmission in a mine shaft for signaling to or from a cage. Therefore, all efforts were directed to devising a practical way of using the hoisting rope as part of the circuit. It was realized that the return circuit from the rope would need to be through electrostatic coupling between the cage and the earth or ground sides of the shaft, because the guides would not always be wet enough to make possible good electrical contact between the cage and earth, therefore relatively high-frequency alternating current was chosen as the medium of transmission. Soon a practical system was developed for transmitting an electric current from a moving cage over an electric circuit of which the hoisting rope was a part. A high-frequency electric current is used as a carrier to transmit the signals or mes-

Jan 1, 1941

By Luis Fortunato Rioja

Southern Peru, es una empresa minera que explota cobre a Tajo Abierto, en cuyo proceso de explotación del mineral se utiliza un sistema mecánico manual de introducción de las barras de acero a los molinos que genera una serie de problemas como el mayor empleo de mano de obra, carguío mecánico manual, inseguridad y la elevada pérdida de producción anual. En ese sentido, el presente trabajo señala el uso del equipo “Fighter Bull" para introducir las barras al molino en el menor tiempo posible. El diseño de este equipo se desarrolló en los Talleres de Maestranza de Toquepala de nuestra empresa Southern Peru Copper Corporation y permite reducir en gran porcentaje las pérdidas de producción de molienda de mineral y no produce riesgos de accidentes de accidentes para los trabajadores.

Sep 19, 2006

By K. J. Ma, L. Ma, J. Stankus

The paper’s intent is to evaluate pumpable foamed cementitious mine seal material by determining the shear strength of a generic foamed cement in the laboratory. The tests were conducted on three scales: small-size specimens, consisting of cylinders 4 in. in diameter or 3-in. prisms; double shear medium- size specimens, measuring 13 in. by 10 in.; and large-size specimens, measuring 6 ft by 4 ft by 4 ft. The small-specimen shear tests resulted in average peak and residual shear strengths of 128 psi and 56 psi, respectively. These values are fairly consistent with published shear strengths of foamed cementitious material. However, the other two types of shear tests did not achieve the shear strength of a typical pumpable foamed cementitous mine seal material. Based on the test results, the paper concluded that the structural analysis of cement foam seals should be based on their residual shear strengths, approximately 20 psi, determined from small laboratory-scale tests of the cement foam/concrete or rock interface, and not be based on their peak strengths.

Jan 1, 2015

By Bowles Oliver

"Modification of Quarry Process.Limestone beds are formed by processes of nature, processes that have been in operation for thousands and perhaps millions of years. Therefore, their com- position and physical properties are long-established and unalterable features over which man has no control. He must take them as he fields them.It is undoubtedly true that the character of lime depends largely on the nature of the parent limestone. A high-calcium lime cannot be manufactured from a dolomite, nor can a pure lime result from the calcination of an impure raw material. However, in the process of turning limestone into lime man is not entirely helpless in his control of quality. Even though a deposit is variable in character a single lime product of uniform quality may be produced by judicious quarrying. A single grade of product may not always be desired, the producer may wish to supply the needs of a variety of users each demanding U different grade or quality of lime such a series of graded products may be produced in part at least by modifying the quarry method. Thus, by changes in quarry practice a single product or a variety of products may be made. The latter problem will be considered at a later time, and the present paper devoted to the first named question' that of producing a single grade of lime from a deposit of variable rock,It is realized of course that uniformity in the product is influenced greatly by manufacturing processes such as calcining' hydrating' grinding or storage, but the present discussion is confined to the influence of raw materials only. In considering the various devices that may be employed it is realized that much remains to be learned, and it is hoped that many operators will contribute to the discussion as they have already done in connection with previous papers of this series."

May 1, 1923

By J. G. Walters

In 1928, the Coal Carbonization Section of the Federal Bureau of Mines, in cooperation with the American Gas Association, began a survey of the carbonizing properties of American coals. A standard test method for evaluating the carbonizing properties of coals that met the following conditions was developed: To yield products similar to those obtained in commercial operations. To produce yields sufficient to permit analyses and tests of quality. To be laboratory size. To be convenient to operate. To permit reproducible control of test conditions and results. This test method has become known as the Bureau of Mines-American Gas Association (BM-AGA) test (53),3/ and more coals of greater variety have been tested in this apparatus than in any other of similar scale.

Jan 1, 1961

By W. J. Tough

THIS paper offers examples of some of the typical calculations which occur in the ventilation of metal mines. The fi.rst section of the paper discusses the problems associated with natural-draft pressure; the second section presents the more common of the calculations concerned with the operation of mine fans; the third section illustrates the integration of the individual problems covered by the preceding sections into the larger problem of determining the operating characteristics of a fan for a particular mine duty. There is a very definite limit to the extent to which pure arithmetic can be successfully applied to the solution of min<; ventilation problems. As mines advance from the exploration, development, and initial production stage to the rime when underground workings become exceedingly complex, there is a considerable increase in the relative importance o theory and judgment in the solution of ventilation problems. These calculations illustrate the application of mathematics to ventilation, but they also in-elude examples of instances where arithmetic cannot be conveniently applied, and important estimates, based on judgment compounded of experience and a knowledge of the theoretical consideration involved, must be made. The inclusion of such estimates is intended as a guide and a warning to the reader; a guide in assisting him to recognize and estimate his own incalculables; and a warning that the solutions must not be blindly applied to his apparently similar problems. These sample calculations are intended to assist the reader in applying the theory contained in the standard texts on metal-mine ventilation. They have been selected from the ventilation experience of a British Columbia mine.

Jan 1, 1942

By Rov G. Stott

In recent years there has been no loss of life from fires in the underground mines of the Lake Superior district, but numerous minor fires and several serious ones involving loss of property and production have occurred. The iron-ore-producing companies recognize that well-equipped mine rescue stations are a valuable asset against the ever-present ranger of mine fires or the possibility of hazardous atmospheric conditions underground. Prompt action by trained and properly equipped rescue teams is recognized as the prime essential in saving lives, property, and production when fires occur. To achieve this purpose, the mining companies have provided themselves with mine rescue equipment and maintain trained mine rescue crews. This circular describes how one progressive company has provided, maintained, and improved upon such protection for its underground iron-ore mines on the Marquette and Menominee iron ranges of Michigan&apos;s upper peninsula. SUMMARY The central mine rescue station of The Cleveland-Cliffs Iron Co. at Negaunee, Mich., has provided the company&apos;s mines with competent and well-equipped mine rescue teams. The new central mine rescue station at the Mather mine "B" shaft has the distinction of having underground training facilities provided as a part of the station. The company maintains the largest trained force in mine rescue in the Lake Superior district, and mine rescue training is employed as a part of the accident-and fire-prevention program. One of the most important results has been the promotion of closer cooperation and understanding between the management and the workmen. In addition to the service rendered to company mines, the station and its personnel have given assistance to others. The station and its equipment have also been used for training several nearby community volunteer fire departments. This mine rescue station and its personnel have been a dependable and valuable asset to the community in which it is located.

Jan 1, 1954

By Noan Tonini SImonassi

Fibras naturais lignocelulósicas, como piaçava, curauá, juta, rami, dentre outras, estão sendo empregadas como reforço de compósitos de matriz polimérica para melhoramento de propriedades mecânicas desses. Sendo assim, o presente trabalho tem por objetivo a investigação da resistência ao impacto de compósitos com matriz epoxídica reforçados por tecido de fibras de rami, fibra extraída do caule da planta de rami, nativa da Ásia Oriental. Para tanto, ensaios de impacto Izod foram realizados e mostraram que a incorporação dessas fibras incrementa a absorção de energia de impacto dos compósitos e que a resistência ao impacto aumenta com a quantidade relativa de fibra reforçando o compósito. Este desempenho pode ser associado à dificuldade de ruptura imposta pelas fibras bem como ao tipo de trincas resultantes da interação tecido/matriz.

Aug 17, 2017

By Dr. G. R. Hoey

"Abrasive wear and corrosive wear of carbon-steel grinding balls occurred simultaneously during the wet-grinding of hematite iron ore, and Ni-Cu sulphide ore, in laboratory ball mills. Two corrosion control methods, the use of corrosion inhibitors and pH control, were investigated and found to be effective means of reducing or preventing corrosive wear. Up to 50 % reduction of total ball wear resulted from the use of these methods.Corrosive wear is caused principally by the reaction of oxygen in air with the carbon-steel grinding balls, probably by the following reaction: 2Fe + O2 + 2H20 - 2Fe2 + 40H-.IntroductionA survey of corrosion problems in Canadian sulphide ore mines was completed and the findings were published in 197l(l). The corrosion survey was used to develop the present research program with the objective to find more economical and effective ways and means to reduce the corrosion that occurs in the mining and metallurgical industry. The purpose of this presentation is to review the projects being done by staff members of the Corrosion Section, Extraction Metallurgy Division, on corrosive wear and its control in wet-grind ball mills.Both abrasion and corrosion contribute to metal consumption during wet grinding of ores. The total wear of grinding media in this study is assumed to be equal to the sum of corrosive wear and abrasive wear. A great deal of research and development has been reported in the literature on ways to improve the abrasion resistance of grinding media but only a small number of studies has been reported on the corrosion resistance of conventional grinding media."

Jan 1, 1974

By Edward Keller

THE present ruling principle in shop and factory, induced by conditions of. keen competition, is to do the greatest amount of work in the shortest time, or in other words, to secure the greatest output at least cost, a condition which generally necessitated the substitution of machinery for manual labor. The chemical laboratory in our industrial establishments has remained a factor of minor importance, and, for this, reason, not only has progress been permitted to lag, but the methods of analytical work have been carried on along individual traditional lines. Some works-laboratories are equipped with such conveniences as Gooch filters, suction-pumps, compressed air, shaking-machines, centrifugal machines, crushers, etc., yet there is much room for improvement, particularly in laboratories of metal smelting and refining plants, in which long series of filtrations and stirrings are performed singly by hand in a slow and laborious manner. There are also many other instances in which collective handling appears rational. As a rule the chemist wastes much time by such manual labor, which, in a modern establishment and under up-to-date management, could be more advantageously applied to useful chemical work; and such higher chemical work is gradually and surely becoming recognized as an essential extension of old-time methods of assaying. While it maybe said that in some laboratories, boys and not chemists do the manual labor, it should be borne in mind that all chemical work requires care and accuracy and in these respects boys are naturally a source of concern to the responsible chemist. Moreover, the cheapness of child-labor is largely offset by the increase in the expense-account of laboratory materials, caused chiefly by breakages resulting from care¬lessness. Having; been authorized by the Anaconda Copper Mining

Mar 1, 1905

By Charles Will Wright

MINERAL production in almost all European countries suffered a sharp setback because of the war. Plants were damaged, transportation facilities disrupted, and labor dispersed and demoralized. Since the war, due to lack of confidence and economic stability, there has been little incentive to rebuild and expand the mineral industries even though a big demand at high prices exists for mineral products. Most mining and metallurgical companies in Europe hesitate to invest their capital because of the tendency towards nationalizing industry, high taxes, and low output of labor, as well as the deficiency of mine supplies and equipment within their countries. In short, they do not have faith in the future, and for these same reasons and fears most of the mining companies in America will not risk capital investment in Europe. In Europe, including the United Kingdom, free enterprise has been losing ground and as a result the foundation of their economic welfare is being undermined. American mining interests willing to take the initiative could help in counteracting this influence if a way were found for them to co-operate with the European producer without too great a risk.

Jan 1, 1948

By Michael G. Nelson

Control of the feed provided to mineral processing facilities is a continuing challenge. Much effort is currently being devoted to overcoming these problems. These projects are usually described under the general headings of Mine-to-Mill Integration or Mine-Mill Optimization. It should be possible to combine the knowledge of ore type, mineralogy, and other characteristics (located in the mine modelling system), with the advanced capabilities of state-of-the-art mill control systems, to achieve an improved level of control in mineral processing, allowing optimization of the mill processes on an almost realtime basis. This is not happening because mill feed it is often treated as a uniform material, when in reality it varies in composition and characteristics. The University of Utah is investigating the use of odor sensors for maintaining traceability in ore production and processing. Odor sensors now used in food processing, environmental monitoring, and other applications can detect the presence of very small amounts (0.1 - 500 ppm) of some molecules. An assortment of such molecules could be used to ?tag? blocks of ore as they are mined, according to their respective characteristics. Then, as the ore came into the mill, an array of ?electronic noses? could be used to assess its characteristics in real time.

May 1, 2004

By Jorge Medina R.

"Después de dos años de preparación para adoptar un sistema de gestión de calidad de acuerdo con los requerimientos de la norma ISO 9001:2000, la Planta LESDE de Southern Perú Copper Corporation en Toquepalay Cuajone acreditó su sistema de gestión de la calidad a su producto (cátodo de cobre) en la auditoría de certificación. En ese sentido, el presente trabajo señala la aplicación del sistema de gestión de calidad ISO 9001: 2000 en cátodos electrowon en la SPCC a través del diagnóstico, compromiso, planeación, capacitación, documentación, implementación, auditorías internas, preauditoría, certificación, visitas de seguimiento, participación del personal y las optmizaciones esperadas respecto a este tema. Asimismo, es importante integrar la gestión de la calidad en seguridad, salud, y medio ambiente y así lograr la certificación ISO 14001:2000."

Jul 31, 2003

By Ruddle R. W.

Magnetite occurs in the reverberatory furnaces, blast furnace and converter (a) as the result of its presence in the materials charged, and (b) as the result of oxidation of the FeS in the charge in the absence of sufficient SiO2 to slag the FeO as it is produced and thus prevent its subsequent further oxidation. Magnetite is reduced by FeS according to FeS+3Fe3O4=10FeO+SO2 and similar reactions. This reaction is markedly affected by temperature and does not proceed to any important extent below about 1200°C. To ensure comparative freedom from magnetite it is therefore necessary to raise the temperature of the furnace to the highest practicable figure and to use plenty of siliceous flux. Since the maximum operating temperature is likely to be limited by the resistance of the refractories to attack by the slag, investigation of the factors affecting this attack should be helpful. It is reasonable to suppose that the formation of magnetite might be minimized by ensuring intimate admixture of matte and slag during conversion so that silica is readily available for combination with ferrous oxide as the latter is formed. The literature gives no clue to the importance of this factor and some experimental work on this aspect might be fruitful

Jan 1, 1953

By Clayton A. Landsidle

There has been little change in timbering methods in anthracite mines for 75 years, and technical information on strata control is almost wholly lacking. In order to assist the industry to establish technical data, the Bureau of Mines and a Northern field operator are cooperating in underground experiments, the first phase of which has been to investigate pneumatic packing. The four principal methods of packing in mining are hydraulic, pneumatic, mechanical, and hand. The hydraulic pa caring system is believed to have originated at Shenanodah, Pa., in 1864,4/ to prevent destruction of a church by surface subsidence after underground coal mining. This method was used again in 1884 to arrest an underground fire at Buck Ridge colliery, near Shamokin, Pa. In 1901 hydraulic packing was introduced to Europe in Upper Silesia, where it gained in popularity owing to the availability of large quantities of sand suitable for flushing .5/ Hydraulic packing has a number of disadvantages. Chief among these are the softening effect of large quantities of water on the mine floor conducive to heaving action; drainage and punning costs; and the inability to fill roof cavities completely in flat beds.

Jan 1, 1953

By R. C. Canby

JUDGE GRANT, in a delightful satire of his, says: "Boston is a state of mind." I think that this same statement might well be made of the metallurgy of lead. I was particularly impressed with this when about thirteen or fourteen years ago I prepared a paper on "Development of the American Water- jacket Lead Blast Furnace." Dividing the time, as I did into ten-year periods, from the commencement of lead smelting at Eureka, Nev. (1870), and showing the tendency for each of the five decades it was evident that the progress had been through a succession of states of mind from the rule of thumb through the ultra scientific, or from what I might call the slag type period up to the present highly developed art. Conservatism has been characteristic of the metallurgist. This may have been most natural, especially with the lead metallurgist, the development of whose art was so entirely in the custom smelting plant, where the metal contents of his ores were paid for in cash and therefore excessive metallurgical losses could mean nothing short of financial bankruptcy. The metallurgist himself was held to a personal account, in these smelting plants. It was the metallurgist who was accountable. In the concentrating plants, if undue losses occurred remodelling of the plant was discussed, but if there were excessive metallurgical losses in the custom smelting plant, a new metallurgist was considered as the remedy. For this reason the tendency was to adhere to recognized practice and to be wary of unusual methods, using the word unusual in the sense in which it is used in Article VIII of the Constitution of the United States, as to punishments and modes of death. This conservatism of the metallurgist was reflected as other branches of metallurgy were developed. We have heard of the wonderful development of flotation, but it had to be introduced over the dead metallurgical bodies of its opponents.

Jan 1, 1926

Olympic Dam Operation is located in the Stuart Shelf Geological Province approximately 520 km north-north-west of Adelaide in South Australia. It is estimated to be one of the worldÆs top five copper orebodies by size and the biggest single occurrence of uranium. The deposit was discovered by Western Mining Corporation in 1975. Exploration was based on a conceptual model for the formation of sediment hosted copper deposits together with gravity and magnetic anomalies.The capital cost of the current expansion is estimated to be A$ 1.64 billion. The underground expansion includes a total of 36 km of lateral development, a railway haulage system delivering ore from a series of ore passes to a new crusher station and a significant increase in ventilation capacity and mine services.In the current underground expansion the mining method will essentially remain unchanged. The ore handling system will incorporate some recent advances in technology, improving efficiency and safety standards.Major infrastructure excavations are designed by a team of engineers attached to the Olympic Dam Expansion Project and a number of consulting groups. Once the expansion is fully completed it is expected to increase the current annual underground production level from 3.4 Mt to 9.0 Mt of ore by the year 2000. Mine design engineers working for the Olympic Dam Operation have recently completed a three year final design plan to achieve this target.Access to the existing mine is through the decline and Whenan shaft. The Whenan shaft was originally sunk as an exploration access and later upgraded for hoisting. The 4 km long service decline connecting to the Whenan shaft was later constructed to accommodate the increase in service demand. The Robinson and Sir Lindsay Clark shafts were developed at later stages to cater for the hoisting during and following the expansion lead up.

Jan 1, 1999

By Ben E. Adams

The Duval Corporation Sierrita copper and molybdenum mining complex is located approximately twenty-three miles south of Tucson, Arizona. The original open pit mine, Esperanza, was put into operation in 1958 and utilized one tailings dam until the Sierrita operation began in 1970, and a second pond was started. Both tailings operations continued to be operated separate and independently of each other until 1977, when the Esperanza Mill was temporarily shut down, and the Esperanza Tailings Dam was retired from service. Except for short periods of use, no new tailings were put on the surface. With the reactivation of the Esperanza Mill in 1979, the Esperanza tailings were combined with the Sierrita Mill tailings and put on the Sierrita Dam, leaving the Esperanza Dam in a retired state.

Jan 1, 1984

By G. F. Friel

A series of experiments in the U.S. Bureau of Mines Safety Research Coal Mine at the Pittsburgh Research Center evaluated the effects of crosscuts on the travel time of carbon monoxide (CO) along an entry to improve the accuracy of a mine-fire locator program. Three entries, ten single crosscuts, and three double crosscuts were instrumented with CO sensors. One-percent CO in nitrogen was released and monitored as it traveled the entries. In addition to dispersion of CO at the front of the CO wave, CO was entrained from the entry into the crosscuts. It was determined for an entry and single-crosscut configuration that the measured travel time for a concentration change of 5 ppm was 27% greater than the predicted time based upon entry volume only, but 13% less than the predicted time based upon entry and crosscut volumes. For an entry and double-crosscut configuration, the measured travel time for the same concentration change was 25% greater than the predicted time based upon entry volume only, but 10% less than the predicted time based upon entry and crosscut volumes. An effective dispersion coefficient for CO dispersion along one of the entries was estimated to be 1.5 m2/ s.

Jan 1, 2010

By Usiminas -. Ipatinga e Cubatão

Objetivo: Apresentar o Balan&ccedil;o Energ&eacute;tico Global da Usiminas em 2013 - Usinas de Ipatinga e Cubat&atilde;o, com os principais indicadores de consumo das &aacute;reas produtoras. Al&eacute;m dos indicadores energ&eacute;ticos globais, o balan&ccedil;o apresenta os consumos f&iacute;sicos espec&iacute;ficos de cada insumo nas diversas &aacute;reas, permitindo a an&aacute;lise de cada setor das Usinas, isoladamente. Metodologia: Foram elaborados gr&aacute;ficos com indicadores de consumo energ&eacute;tico por um per&iacute;odo de cinco anos, bem como a distribui&ccedil;&atilde;o percentual nas &aacute;reas produtoras. Nestes gr&aacute;ficos, &eacute; evidenciada a evolu&ccedil;&atilde;o dos indicadores ao longo dos anos. &Eacute; tamb&eacute;m apresentada justificativa para a varia&ccedil;&atilde;o do indicador em rela&ccedil;&atilde;o ao ano anterior. Resultados: O trabalho apresenta an&aacute;lise das Usinas de Ipatinga e Cubat&atilde;o em rela&ccedil;&atilde;o &agrave; evolu&ccedil;&atilde;o do consumo energ&eacute;tico e sua distribui&ccedil;&atilde;o percentual nas &aacute;reas produtoras.

Jul 31, 2018