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By Charles D. Clarke

Para mantener el drenaje de las instalaciones de las bombas en Cerro de Pasco se necesita un aproximado de 3700 galones por minuto. Empero del total de los 3700 galones por minuto, 2500 es agua ácida y el restante; 1200, es agua dulce. Por tal motivo, el objetivo del siguiente trabajo es revisar los problemas de mantenimiento de las bombas -en tanto represente la consecuencia del agua ácida de las minas-,para reducir los costos y las causas de deterioro, asimismo reparar en las corrientes extraviadas como causas corrosivas serias, que necesitan ser adecuadamente protegidas desde el momento de su instalación y supervisadas periódicamente, Por último, aislar adecuadamente las bombas de las corrientes extraviadas, reduciendo la posiblidad de la acción galvánica de los equipos eléctricos instalados a proximidad.

Jul 20, 1955

By Augusto Díaz Rodríguez

Como parte de la campaña de seguridad y prevención de accidentes producidos en las minas de San Antonio de Esquilache, el autor del presente texto expone una serie de medidas que permitan reducir el índice de siniestros producidos durante las labores tales como: golpes con herramientas, carroneo, explosivos, lesiones, caídas de piedras por chimeneas, de trozo y minerales en los buzones, etc. Para ello, resalta la creación de organizaciones dedicadas a prevenir dichos incidentes, así como la aplicación de un programa de seguridad que incluya el uso de cinturones de seguridad, acuñado de los techos y galerías mediante barretillas, limpieza de caminos y carretillas, supervisión contínua de los caminos de las minas, equipo de seguridad del trabajador, et. Por último, la permanente charla de capacitación del personal de seguridad, como la cooperación de los trabajadores durante este proceso, disminuye la cantidad de 4o accidentes mensuales a 2 desarrollados en los últimos meses en la mina.

Jul 20, 1955

By Godofredo Murillo P

"El objetivo del trabajo es señalar la aplicación del método de sostenimiento a través de los ""pernos de madera"" en las minas de Colquijirca, Cerro de Pasco. La ejecución de este método fue a raíz de la lectura de una de las publicaciones que edita el American Institute of Mining and Metallurgical Engineer, titulada Mining Engineering. Posteriormente se elaboraron varias pruebas, encontrándose en está ultima, un rajo de 18 metros por 6 metros, levantado un promedio de 2 metros y medio, y en el que se colocan los pernos de modo perpendicular a la inclinación del manto, llenando todo el rajo y acomodándose en el rombo. Asimismo se demostró que la fabricación de ""pernos de madera"", cuñas y cabezales en un tiempo de cuatro horas, es mucho mayor que las colocadas regularmente con un ayudante. Por último, se resalta que la eficacia de este método responde al factor de que la roca floja es sementada dentro de un bloque sólido, que es suspendido por los lazos del cable de acero en los huecos perforados en un zona sólida, dando mayor seguridad a los trabajos de sostenimiento en los rajos, asi como facilidad en sus instalaciones."

Jul 20, 1955

By Juan Manuel Candia Vargas

"El siguiente trabajo refiere los métodos de explotación empleados en la mina San Antonio de Esquilache por la Compañía de Minas del Perú, considerando previamente los métodos de preparación y desarrollo empleados. Para ello, se describen primero las labores de acceso, constituídas por los socavones de cortada, siendo el más utilizado el ""Farrallón"" que conduce el relleno a los parajes y la explotación de los minerales explotados, mientras que el ""Hardy"" se encarga de la extracción del mineral. Luego están las labores de desarrollo, comprendidas por las galerías y chimeneas sobre veta, donde las primeras son proyectadas a una diferencia de nivel que varía de 30 a 40 metros y a una distancia fija de 30 metros las segundas. La preparación de los tajeos se inicia con el ""desquinche"" de las galerías, al tiempo que se coloca la enmaderación. Por último, se da la explotación por corte y relleno en el que este último está completo antes del rajo."

Jul 20, 1955

By Alberto J. Terrones

"En la actualidad mundial, la exploración de zonas mineralizadas se hace cada vez más restringido, dada la demanda de metales y el progresivo agotamiento de las reservas. Por ello, se realizan estudios geológicos previos que permitan una exploración sistemática de las minas a mayor profundidad. Siguiendo esta ruta, el éxito del descubrimiento de algunas zonas mineras en el Perú, radicaría en las áreas donde la erosión es un factor determinante de la trascendencia o intrascendencia del tonelaje del mineral. Por tal motivo, el objetivo del presente trabajo, es señalar las características de los métodos modernos de exploración minera, aplicados al enfoque de las áreas principales para un futuro explotación de tonelajes de mena. Todo esto a partir de una naturaleza metódica y sistemática de las investigaciones geológicas preliminares, incluyendo las fases de su ejecución, posición, orientación, longitud, orientación, longitud y costo de los trabajosde exploración primaria, tales como socavones, sondajes, diamantinos, trincheras, etc., al tiempo que indique la potencialidad que puedeesperarse del yacimiento o yacimientos que se investigan."

Jul 20, 1955

By Carlos R. Tapia

"El presente trabajo describe los métodos de explotación aplicados en la mina Carahuaca, así como una breve historiografia y contexto del yacimiento minero. En este punto, registra la ubicación de la zona minera en la provincia de Yauli, departamento de Junín, cuya geología desarrolla tres depósitos minerales tales como el depósito Norte o principal, el depósito central o viejecita y el depósito Sur o pantano. El sistema de explotación se da a cielo abierto (sistema de bancos), y pertenece a una zona mineralizada y subterránea (tajos de corte y relleno y sin entibación), la misma que se divide en dos operaciones: la remoción de la zona estéril del pendiente de la zona mineralizada y parte del yacente para dar a los bancos la inclinación final y la subterránea( tajos de corte y relleno aislados por entibación completa con cuadros ensamblados). Por último, se encuentran las labores de exploración y desarrollo que descubren, bloquean y atacan las secciones del mineral explotable (recortes y galerías, enmaderación y profundización del pique maestro al nivel 50)."

Jul 20, 1955

By E. Ackerman, L. Y. Tu, S. C. Sun

The use of ultrasonics in forming emulsions is not new. As early as 1927 Wood and Loomis' reported preparation of emulsions with ultrasonics. In 1935 Rschevkin and Ostrawskyz described the use of great ultrasonic power in producing fine emulsions of various oils and paraffin in water. Recently Oyama and Tanakahmployed ultra-emulsification to increase the effectiveness of sodium ethyl xanthate in flotation of chalcopyrite and galena. An emulsion is a two-phase system consisting of two incompletely miscible liquids, the one being dispersed as finite droplets in the other. The dispersed liquid is known as the internal or discontinuous phase, and the surrounding liquid is termed the external or continuous phase. There are two types of emulsions; one is oil-in-water (O/W) and the other water-in-oil (W/O). The word oil refers to the liquid other than water. Circumstances exist in which the emulsion type is not clearly defined, and the internal and external phases both contain portions of the opposite phase. This is said to be a dual emulsion. Among the many hypotheses', 6v proposed for the formation of emulsions, the Bancroft's adsorbed film or double interfacial tension theory is widely accepted. Bancroft ""educed that in the process of emulsification the interfacial tension between oil and water is lowered by the formation of an emulsifying film, which contains the adsorbed molecules and/or ions from the emulsifying agent and the two liquids.

Jul 1, 1955

By G. A. Vissac

In continental Europe the feldspar jig is used almost exclusively for cleaning the fine sizes of coal; it operates with an artificial bed, made up generally of pieces of feldspar or of any other hard and heavy rock with good cleavages. A primitive form of this machine requiring close supervision was used in this country years ago, but output was small. The modern machines are generally air-pulsated Baum-type jigs, with capacities up to 150 tph, and treat sizes from 3/s in. to 0, usually previously dedusted or deslimed. These jigs are equipped with very accurate and sensitive automatic controls insuring satisfactory operation even at low separating gravity and with feeds irregular in quality and quantity. This paper will deal more particularly with coal cleaning separation, but the technical studies apply equally to all minerals.

Jul 1, 1955

By Silvio Hernández Aquije

El presente texto señala el descubrimento del yacimiento vanadífero de Minasragra a través del reporte de Yeatman-Berry en 1916 y el de Kett-Sproul en 1931. Así también señala los tipos de mineralización como la mineralización primaria y por impregnación.

Jul 1, 1955

By Leon Merker

Flame fusion growth of strontium titanate crystals was undertaken to obtain large transparent crystals on which physical data could be gathered. The fact that strontium titanate is a cubic crystal and probably has a high index of refraction indicated that it might be useful in optics. No large boules* of strontium titanate had been synthesized previously, and none have been found as natural occurrences. The flame fusion process, invented by Verneuil in 1904, was first applied to grow large crystals of ruby and has since been used extensively to grow crystals of corundum and spinel on a commercial scale. Only during the past nine years has this technique been applied to the growth of large single crystals of other high melting compounds such as rutile, mullite and ferrites.

Jul 1, 1955

By John D. Ridge, Robert C. Barwick

The quantities and destinations of the metallic ores and concentrates and partially or fully refined metals in international trade result from the interaction of many factors, of which geographic location is only one. How far the processes of concentration and refining are to be carried in the country in which the mining is done and what dictates the destinations to which the more or less completely processed raw materials will move are determined not only by present-day geologic, political, and economic conditions, but also by the patterns set up by these same conditions as they obtained in the past. The first generalization that can be made regarding trade in metal raw materials-one that affects the form in which the material is transported, rather than the patterns followed by that trade-is that concentration is carried out for all low grade ores, nonferrous or ferrous, in the country in which they originate. (Rule 1.) Economic considerations alone almost always require that this be done; only high grade iron, manganese, and chromite ores can be shipped as they are mined.

Jul 1, 1955

The old single-jack may have been portable- but it left much to be desired in drilling speed and depth of hole. Portable compressors for drilling can be snaked into tough spots. However, that calls for more men, equipment, and money, with corresponding loss of mobility. The drills listed in this notebook sheet meet three requirements: They are light. They are self-powered. And all are reported proven in practice. Undoubtedly there are other units filling the requirements that are not listed. Extreme mobility for far-flung exploration teams is always an acute need. The drills listed here help solve the problem. Canadian Longyear, for instance, reports that the Porta drill has been parachuted into wilderness spots and helicopters have lofted light core drills onto mesa tops in the Colorado Plateau uranium country.

Jul 1, 1955

Bethlehem Steel Co. has just brought an all-new iron ore mine into production at Marmora, Canada, about 120 miles east of Toronto. High grade pellets produced at the mine from open-pit magnetite ore travel 64 miles by rail to the port at Picton, then go by Lake boat to help supply Bethlehem's Lackawanna, N. Y., plant. At full production about half a million tons of pellets a year will be shipped, and mining will be at a scale of more than a million tons per year of ore. Aeromagnetic surveys carried out in 1949 by the Ontario Dept. of Mines and the Canadian Geological Survey revealed an anomaly that interested Bethlehem geologists. By 1951 the company had put down some 40 diamond drillholes ranging from 460 to 1800 ft to block out the magnetite replacement deposit which lies in pre-Cambrian limestone below about 130 ft of Paleozoic limestone. The orebody, roughly 2100 ft long and up to 400 ft wide, averages about 37 pct iron, too low for direct shipment. Not only construction of concentrating and pelletizing facilities, but 20 million tons of stripping lay ahead before production could start

Jul 1, 1955

By Luis Alva Saldaña

"Actualmente el método para descubrimiento de nuevos procesos y la elaboración de nuevas técnicas se ha modernizado. En ese sentido, el presente artículo señala la invención de estos procesos y técnicas a través del estudio de la Termodinámica. Esta ciencia trata de las relaciones entre las diversas formas de la energía, mostrando cuantitativamente los efectos que experimenta el complejo materia-energía cuando en él se realizaalgún cambio. Por ello, es fácil observar que muchos laboratorios tanto de Europa como de los Estados Unidos de Norteamérica, realizan estudios no sólo para completar las tablas de propiedades termodinámicas de las sustancias químicas, ya existentes, sino también para revisar los datos que antes se tenían de éstas."

Jul 1, 1955

By H. Tanner, T. Heikkinen

In1950 studies concerning mining and milling of the approximately 17 million tons of ore remaining at Outokumpu revealed the surface facilities for economical treatment were inadequate. The two shafts would soon be too far from the mine workings. Moreover, in spite of several extensions, mill capacity was insufficient and recoveries were not satisfactory. Therefore it was decided in 1951 to sink a new shaft and to build a new mill and auxiliary surface buildings around the shaft. The new shaft was sunk near the center of the remaining orebody, about 650 ft from the ore to the footwall side. This location placed the main part of the shaft as well as the crusher rooms and the ore bins around the lower end of the shaft in the firm and strong mica-schist.

Jul 1, 1955

By V. Vahatalo, E. Hakapaa, H. Tanner

Recently modernized, the surface plant of the Outokumpu mine in Finland incorporates a number of ideas meriting close scrutiny from this side of the Atlantic. The mining methods make extensive use of concrete in some unusual ways. Design of the headframe and surface plant represents the latest thinking of European engineers and includes an integral Koepe hoist. The deposit is in eastern Finland, province of North Karelia, 30 miles west northwest of Joensuu and at 60'44' N, latitude. Pyrrhotite, pyrite, chalcopyrite, and sphalerite mineralization occurs in a shear zone in quartzite near a body of serpentinite. Two lenses have a total length over 12.000 ft, with remaining reserves of the 3 to 4 pct Cu ore estimated at about 15 million metric tons.

Jul 1, 1955

By Otto W. Nuttli

The magnetic method of prospecting is well suited to determination of faulting in the basement rock. In addition to establishing the horizontal position of the fault, it often furnishes valuable information concerning the depth and amount of faulting. Consider a simple case of a vertical fault, represented in cross-section in Fig. 1. Let AA' represent the plane of observation (ordinarily the surface of the earth), and BB'B"B"' the upper surface of the basement. Assume that the sedimentary rocks are nonmagnetic, so that the magnetic susceptibility of the material above the basement is zero. Let k indicate the susceptibility of the basement rock, a- the density contrast between it and the neighboring sedimentary rocks, and t the amount of vertical displacement.

Jun 1, 1955

By B. E. Blair

"This report presents the physical properties and related geological and petrographic data of some 84 rock types from operating mines, quarries, or blasting research test sites. These fundamental rock data were collected as a quantitative approach to underground mining problems, blasting research, or other related studies; however, the data are equally applicable to any problem wherein rock characteristics are important factors. Stress-strain curves are given where available, and the standardized procedure for determining elastic constants from static tension tests is described. Computed (laboratory) and measured (field) free-medium velocities are compared in those instances where such data are available. A chart is given showing both the optimum and minimum number of test specimens for the various core sizes employed in the Bureau of Mines standardized physical-property tests. Rock-type, geographical, and geological indexes are included to aid the reader in locating physical-property data in this and previously published Bureau of Mines physical-property reports.INTROD'OCTI ONThis report presents the physical properties of 84 rock types tested from 16 different projects (sections 37-52). Two previous physical-property reports 2-3 / (hereinafter referred to as parts I and II) presented data on 160 rock types from 36 different projects (part I, sections 1-25 and part II, sections 26-36).The physical-property data were originally obtained to supplement structural mining problems, seismic studies, or related investigations; however, they should be equally applicable in all fields of studies where the strength, hardness, or other properties of rock are important factors. The properties, determined from laboratory tests performed on diamond-drill core, include the following:"

Jun 1, 1955

By J. H. Soulé

"The Copper King copper-gold-silver deposit was discovered about 1880. Various individuals and companies have been interested in the deposit and considerable work has been done, although production, if any, has been small. The deposit is located in the western part of Laramie County Wyo., and is favorably nituated with respect to rail and truck transportation and high-tension power facilities.Mild summers and cold winters characterize the climate. Precipitation averages between 16 and 17 inches annually, with considerable snowfall in the winter. Permanent streams are small and most available water in being stored for use by Cheyenne, Wyo. Range grasses comprise the bulk of the vegetation, with small treed and shrubs common in the most rugged areas.The deposits lie upon land owned by Wyoming, now leased by a group of Wyoming and Colorado businessman constituting the Copper King Mining Co.Primary copper-gold mineralization seems largely confined to an equigranular, relatively fine grained gneiss that is part of a pre-Cambrian complex of metamorphic rocks ranging from schists to pegmatites. The copper minerals are oxidized to a depth of from 100 to 150 feet, with the occasional occurrence of secondary minerals at greater depths. The copper minerals chalcopyrite, malachite, chalcocite, bornite, cuprite(?), and some native copper were observed in Le deposit.In addition to the 4,030 feet of diamond-core drilling in 11 holes done on the deposit by private companies, the Bureau of Mines drilled 3 holes for a total of 2,630 feet. The sample results of this drilling plus available data from previous drilling and sampling are appended to this report."

Jun 1, 1955

By Reynold Q. Shotts

Chemical methods, based on the relative rates of oxidation of fusain, bright coal, and dull coal by nitric acid, have been devised to determine these coal components.1-4 Results obtained by oxidation methods for fusain have been checked against results obtained from microscopic methods on duplicate samples of the same coals, but to the author's knowledge this has not been done for bright and dull coal components. For this reason it is not certain that the two methods of analysis identify essentially the same chemical or physical units. It would be highly desirable to see results of the application of both methods to duplicate samples, but in the absence of any such data the author has attacked the problem indirectly. From the U. S. Bureau of Mines samples were obtained of three Alabama coals which the USBM had analyzed optically and reported on over the past 30 years. These samples were subjected to analyses by oxidation rate methods. Results of this work, and comparisons with the USBM analyses, have been published. This was the first indirect approach to the problem. The present report attempts a second indirect approach by way of internal validation.

Jun 1, 1955