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By A. J. Farstad

The principle objective of the research effort described herein was to identify as rapidly as possible a practical trapped miner location system. Much effort has been expended in the past on the development of a highly sophisticated seismic location system [1] for trapped miners. Field tests of this system have shown that the location accuracy is limited by a combination of seismic velocity anomalies, timing errors, and in general by the relatively weak nature of the signals received at the surface. It was first felt that similar propagation anomalies would be experienced by electromagnetic systems, but to a greater extent than the seismic. However, preliminary tests performed by Westinghouse on the Operations and Maintenance Program, Contract No. H0210063 in 1971 and 1972, indicated that an electromagnetic solution to the location problem may be more feasible than a seismic solution. Thus a more concentrated effort was launched in 1972 and 1973 to more completely determine the feasibility of electromagnetic location systems for trapped miners. Two different approaches to the location problem were undertaken on this program: (1) A pulsed electromagnetic system was developed by the Special Systems Division of Westinghouse in Baltimore, and (2) a Continuous Wave (CW) System was developed by Westinghouse Georesearch Laboratory (WGL) in Boulder, Colorado. Part I of this report will deal only with the development and results of CW Location System developed by WGL. The CW Location System was field tested at three eastern coal mines and at one western hardrock mine. The maximum overburden depth penetrated during these tests was 990 feet at the Robena No. 4 mine near Waynesburg, Pennsylvania. The earth conductivity at this mine was measured to be 1. 1X102 mhos/m, which combined with the deep overburden make this mine representative of expected worst case conditions for a coal mine EM location exercise.

Jan 1, 1973

By James C. Fowler

The design and field testing of a seismic miner detection and location system arc described. This work was carried out over a period of three years. The first two and one-half years were sponsored by Continental Oil Company, while the last period of tests were done as the first part of a one-year contract with the U.S. Bureau of Mines. Laboratory and field experimentation in three different nines under simulated emergency conditions have led to three important results: (1) Taps on roof bolts with normally available objects can usually be detected up to horizontal distances of 1,000 ft. (2) The origin of the tans can be located by on-site processing with a small computer. (3) Some predetermination of the approximate location is necessary for a quick and successful rescue. This report also includes preliminary specifications an,d cost guidelines for construction of a transportable field system capable of matching the performance characteristics of the one used during the field tests.

Jan 1, 1973

1.1 DEVELOPMENT OF INDUCTANCE MATRICES The basic building block in this analytical work is the development of an equivalent circuit. The equivalent circuit for the cable depends on all of the distributed parameters of the cable although the series inductance and resistance are of primary importance. The cable resistances are generally available from handbooks or from cable manufacturers. On the other hand, the cable inductances are not usually available either from handbooks or from the manufacturer's published data. Thus, it is useful to summarize the derivation of the origin of the inductance matrix from basic principles. 1.1.1 Flux Around a Cylindrical Conductor The flux pattern around a cylindrical current carrying conductor can be found by using symmetry in conjunction with Ampere's Law. From symmetry it is clear that the flux lines which always close on themselves must be concentric circles. Thus, from symmetry alone one can get a qualitative picture of the magnetic field. This is shown in Fig. 1.1 where the inner circle represents the solid round conductor and the outer circle represents a flux line. The quantitative picture will now be developed using Ampere's Law.

Jan 1, 1973

By J. C. Irvine

Meramec Mining Co. has put into operation a crushing and conveying system on its newly established 2475-ft level, 200 ft below the lowest production. To develop this level without interrupting hoisting or mine haulage, a 15.8% decline was driven from the 2275-ft level. A 5-cu-yd LHD diesel loader and a diesel-powered drilling jumbo were put into operation midway down the decline, and were used to develop the remainder of the decline and the entire level. Development of the ore pass system to the crusher required the construction of Swedish-type dumps on the main haulage-ways of all production levels with a minimum disruption of ore haulage. Concrete was handled by both rail-mounted and rubber-tired vehicles. The system features four Swedish-type dumps with control chutes at the lower three dumps, a 42-in. gyratory crusher with attendant feeders, and an 1800-ft long roof suspended conveyor feeding two 5000-ton ore bins. The crushed ore from these bins is conveyed to the lower of the mine's two original loading stations for hoisting. The retention of the original dumping and ore pass system as an alternate route has given mine production a unique flexibility. Operation for 22 months has permitted evaluation of the system from a long-term standpoint.

Jan 1, 1973

By Llewellyn A. Rubin

ROUTINES AND SUBROUTINES A- 1 Wait Loop (Wait) A- 2 Receiver Processing (RCVP) A- 3 Control Panel Sequence (CPNL) A-4 Interrupt Routine (INTRP) A- 5 Math Processing Routine (PROC) A-6 Input Constants for Math Routine (CONI) A-7 Angle Conversion Routines (LVERT) A- 8 Display Routine (DSPY) A- 9 Message Print Auxillary Routine (MESSO) A-10 Auxillary Subroutines (AFUTC and AGETC)

Jan 1, 1973

There has been a substantial increase in the use of rubber-tired front-end loaders in the mining industry in recent years. Concurrent with this increased usage, in the period of 1966 to 1970, there were at least 74 mining industry fatalities involving front-end loaders, or (on the average) in excess of one fatality per month. When the usage of front-end loaders by the construction industry and other industries, organizations, and agencies, such as the Government (i.e., Department of Defense), along with the uncounted numbers of serious, but non-fatal accidents, are included in the picture, the safety record for front-end loaders, of necessity, becomes a serious subject for study. There is an urgent need for attempts to be made to eliminate or reduce the number of safety hazards; to decrease the confusing diversity of controls designs found on present front-end loaders; to improve the maintenance and operating procedures; to formulate better personnel policies; to increase management and official awareness of the extent of the problem, in both industry and the Government; etc.; in order to decrease the number of accidents. Part of the problem may be traced to the fact that the operator of a front-end loader is frequently designated a "heavy equipment operator." This implies that he is automatically qualified to operate any model, of any manufacturer's, wheeled or tracked, front-end loader as well as many other types and classes of heavy equipment. Contrary to automotive practice, the complement of primary operating and emergency controls varies widely from model to model, as well as from manufacturer to manufacturer. Not only are certain controls present on one front-end loader model and absent on others, but there are significant differences in the modes of control operation, in the functions performed by superficially similar controls, in the location of the various controls, etc.

Jan 1, 1973

By Arthur W. Ruff

Estimated reserves of high-grade iron ore at Serra dos Carajás total 16 billion metric tons and have an average grade of 66.7 percent iron, 2.2 percent combined silica and alumina, and 0.05 percent phosphorous on a dry basis. Hematite is predominant and no significant sulfur or other deleterious elements are present. Figure 1 illustrates the comparative magnitude of the Carajás reserves. Serra dos Carajás is located in northern Brazil, about 550 kilometers southwest of Belém, Pará. It is six degrees south of the equator between the Xingu and Tocantins Rivers. Both rivers flow northward toward the Amazon River. The greater part of the area is covered by thick jungle, and the most practical means of access is by air. Figures 2 and 3 show the location of Serra dos Carajás. Figure 4 shows the distribution of the major iron-ore deposits.

Jan 1, 1973

By C. J. Edmonds

Of the gold mined in Canada over 90 percent is extracted from the ore by the process of "cyanidation". In this process crushed ore is treated with lime to provide "protective alkalinity" and cyanide, usually in the form of sodium cyanide. The gold is dissolved in the cyanide solution, which after further treatments for clarification, is precipitated by the addition of zinc dust. Wastes from the process consist of tailings which will contain cyanides. Water consumption, mill size, effluent quantity and quality are depicted in transparency (1). It should be noted that as far as the wastes are concerned it has been impossible to postulate a typical situation. Variation from the above data will occur. A summary of data from tailings pond effluents is presented in transparency (2). The figures in parentheses indicate the usual range of values for the parameter.

Jan 1, 1973

By A. Ordoñez

El presente estudio refiere la metodología y los cálculos para resolver el problema del transporte del fluído en el sistema de bombeo, de forma que ayude al diseñador en la selección de números de plantas de bombeo, sistema de la tubería y los diámetros adecuados, así también se describe las características idóneas para las posibilidades de su operación. Las características técnicas y económicas son programadas en FORTRAN IV y se obtienen para cada alternativa los costos de inversión anual dol proyecto con los que se determina la solución óptima. Una vez obtenida la solución óptima para el sistema de bombeo, el diseñador evaluará un programa donde se determine los anclajes y la ubicación de válvulas de aire, considerando ciertas simplificaciones en la estructura que mejoren el análisis del sistema.

Nov 20, 1972

By J. Tumialán

El presente trabajo realiza un estudio comparativo de las propiedades físicas y químicas de tres nitratos de amonio, cuya interpretación se relaciona con las conclusiones sobre estudios de AN-FO realizados en la Universidad de Missuri. Básicamente se evalúa los factores de campo que afectan la performance del AN-FO, como el confinamiento, diámetro del hueco, inicio de la carga y mezcla del explosivo, así como se mide la factibilidad de disparar al AN-FO sin una dinamita. Los tajeos de producción de la mina Casapalca sirvieron de ejemplo para ejecutar dichos disparos, encontrándose que el AN-FO francés es el más adecuado y sensible en torno a la performance de los otros explosivos, dado sus componentes como su ahorro de consumo.

Nov 20, 1972

By Yataro Shimomura

La alza de precios, salarios y las restricciones impuestas por los controles de la contaminación ambiental produjo un aumento en los costos de minado, generando que las operaciones nacionales mineras sean cada más difíciles. Sin embargo, la industria minera logró superarlos, mejorando la tecnología del minado, mecanización y racionalización de sus operaciones. De otro lado, el uso de métodos de minado por cuartos y pilares ha disminuído, mientras que los de corte y relleno y de subniveles se han incrementado. A esto se suma que la utilización de brocas "TC" y del "AN-FO", mejoraron la eficiencia del minado y redujeron los costos. En este sentido, el presente texto señala los últimos avances en tecnología minera a partir de los métodos de extracción, perforación, así como el empleo de relleno de tajeos con relaves de flotación, logrando un desarrollo en la seguridad y eficiencia de la minería subterránea.

Nov 20, 1972

By E Rubio

El imaginario común sobre la construcción de la minería a cielo abierto es que requiere de equipos pesados para obtener mayores producciones. Sin embargo, la aplicación de este método en los minados de vetas de plata en las minas de Julcani de la Compañía de Minas Buenaventura, resultó de gran aporte. En ese sentido, el presente trabajo describe el proceso técnico de este método de explotación en esta producción de plata, asi como señala los beneficios económicos para la pequeña y mediana minería.

Nov 20, 1972

By M. Iberico

A partir de los años 70 se incrementó el proceso de exploración y desarrollo de los yacimientos mineros submarinos. En este sentido, el presente trabajo describe el origen de los depósitos a partir de los descubrimientos de módulos manganíferos en el océano pacífico que hicieron Thompson y Murray. Posteriormente Buchanam demuestra la existencia de módulos ferro-manganíferos en aguas poco profundas ( 200 m. ), de composición diferente de las provenientes de aguas profundas. De otro lado, el trabajo señala también la división de los minerales marinos en tres categorías: las sales disueltas y en organismos, los sedimentos y depósitos en el suelo profundo submarino y los depósitos consolidados e inconsolidados de la plataforma continental. Por último, se describe los procesos de beneficio y las ventajas de la explotación de los recursos submarinos en el futuro de la minería submarina.

Nov 20, 1972

By A. León

El objetivo del presente trabajo es describir el sistema de relleno hidraúlico en los tajeos de vetas angostas de la mina de Morococha a través del método "Arch Back". Actualmente el sistema de relleno convencional es lento, costoso y ofrece desventajas respecto del *R/H. Los objetivos del R/H son aumentar la eficacia de minado, controlar las leyes del mineral, minar los tajeos de baja ley, mejorar el sostenimiento de las cajas y la baja de costo. En este sentido, se describen las operaciones unitarias de los tajeos con R/H y se comparan con los métodos convencionales, encontrando eficiencias en los tajeos aplicados con el método Arch Back y los tajeos de vetas angostas, así como se mejora la producción y los costos de la misma.

Nov 20, 1972

By J. Arce

El presente trabajo describe el proceso de exploración del yacimiento minero de Tintaya en Cusco. Para ello, se realiza un estudio de polarización inducidad y dos perforaciones donde se encontró que dicho yacimiento no se limita al contenido de reservas de óxidos, sino que a partir de esta investigación se pudo localizar gran cantidad de minerales de alcance vertical con bornita y otros sulfuros, considerándolo un potencial de depósito de sulfuros en la minería peruana.

Nov 20, 1972

By A. Meléndez

El presente trabajo señala el proceso del entrenamiento para Ingenieros de minas en la corporación minera Cerro Verde a través del plan de perfeccionamiento profesional elaborado por la misma empresa privada. El objetivo del plan es darle al profesional egresado, la experiencia práctica adecuada que complemente la formación académica. Asimismo se busca la eficiencia de su profesión, desarrollar la competitividad y el estímulo de superación del egresado dentro de la empresa minera.

Nov 20, 1972

By F. De Lucio

Para la aplicación de la instalación de un sistema de relleno hidráulico es necesario evaluar las funciones que el relleno debe contener y determinar si el material a usar cumpla con las funciones especificadas. En ese sentido, el objetivo del texto presenta una interpretación científica sobre tal método para especificar las funciones que el relleno deba cumplir y la metodología experimental adecuada que evalúe cuantitativamente a un relleno hidráulico.. Asimismo, se describen sus propiedades estructurales como la densidad relativa, reducción de volumen y estabilidad de tajeos contínuos, así como los métodos indirectos para inferir dichas propiedades y las posibles consecuencias secundarias que pueda generar el empleo de relleno hidráulico.

Nov 20, 1972

By C. W. Robinson

El presente texto describe el problema del nacionalismo de las realidades de la expropiación latinoamericana. Uno de los principales problemas radica en las relaciones de Estados Unidos con América Latina - en tanto el nacionalismo genera una sensibilidad emocional y política que contrapone la posición del país inversionista extranjero. Por ello, se debe eliminar el aspecto político o desnacionalizar las inversiones extranjerases necesario, de forma que el desarrollo de consorcios para inversiones de mayor envergadura formados por participantes de dos o más naciones, puede reducir el riesgo de ataque político basado en el argumento de 'invasión de soberanía".

Jul 1, 1972

By C. E. Gerity

Near Bunker, Mo., in the New Lead Belt, Ozark Lead Co. operates a 6000 tpd lead-zinc mine. Mined ore is transported to the surface in three mechanized and automated steps. The mine is developed by a rectangular-shaped sublevel haulage drift 15 ft high by 28 ft wide, driven on strike below the ore zones. Ore transfer raises were driven from the sublevel at locations near the shaft, 1500 ft distant, and on subsequent 1000 ft centers. These 6 x 5-ft raises are slashed to obtain maximum storage below dump points. These dump points are located on each mining level and are of steel and concrete construction. Spiral 12 X 24-ft inclines driven from the sub-level provide access to these levels for equipment and mine utilities.

Jan 11, 1972

By F. H. Guise-Brown

Raise-boring experiences in the gold mines of the Anglo American Corporation Group by J. W. WILSON and P. C. GRAHAM Published in the Journal, October, 1972. Discussion by F. H. Guise-Brown., B.Sc. (Min. Eng.) (Member) INTRODUCTION Messrs J. W. Wilson and P. C. Graham are to be congratulated on an excellent paper containing several thought-provoking remarks. The concept of allocating a machine and equipment valued initially at some R300 000 on an experimental basis is courageous, and the results obtained could be of interest to the mining industry as a whole. The Gold Fields of S.A. Group approached this problem differently. In pioneering the start of this work in South African gold mines, they considered that expenditure of this magnitude would be warranted only if the proposition was viable right from the start. To this end, a Robbins R41 was purchased expressly to assist in the duplication of part of the No. 1 shaft system of the Doomfontein Gold Mine. Mr M. J. Koortsl has summed up the initial results of this work and given some preliminary costing, but inflation since that period has made these figures somewhat out of date.

Jan 10, 1972