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By Henry G. Granger

I. INTRODUCTION. REPEATED failures in attempts to work gold-bearing gravels by means of suction-dredges have created the impression that this method is impracticable. The suction-dredges have failed from three special causes excessive wear and frequent breakage of pump-shell, runners and liners; inability to dredge compact gravel which would ,not. readily move towards the intake; and, most important of all, closing. of the suction-pipe by stones too large to enter it. In my opinion, all three causes of trouble may be remedied: the first, by making stronger the parts most liable to wear and breakage; the second, by means for loosening the gravel at the intake; and the third, by sufficiently... Increasing.. the diameter of the suction-pipe. In suction gold-dredges, this diameter has not usually exceeded 10 or 12 in.; whereas there are few profitable gold-fields which can bee considered dredgeable, in which stones more than' 12 in. in diameter, are-.not frequently encountered. II. AN EFFECTIVE SUCTION-DREDGE. In harbor-operations, much larger stones are handled by suction-dredges.., The large dredge of the Henry Steers Contracting Co. worked for nearly four years at League Island, Philadelphia, where it sucked up, passed through the pump, and forced through 3,700 ft. of discharge-pipe; gravel containing boulders up to 200 lb. in weight. This was done with no bad breaks and few shut-downs. The cutter; and liners were the only parts liable to damage, and these were easily replaced with brief interruption of work. The chrome-steel liners are said to have lasted from six to nine months. I am informed that this dredge worked continously for nine

Apr 1, 1909

By Manuel E. González

El presente trabajo refiere las relaciones entre empresa y servidores a cargo del departamento de Relaciones industriales en la Cerro de Pasco Corporation. El desarrollo de las relaciones laborales dentro del yacimiento minero se basa en el medio o contexto, supervisores, fuerza laboral, oficina de empleos, comunicaciones, servicio social, campamentos, etc. Además de considerar estos aspectos, es necesario mencionar que la armonía laboral requiere del cumplimiento de los dispositivos legales del país, la predisposición de los supervisores y personal a cumplir con las condiciones de trabajo, la garantía del derecho del trabajador a expresar sus incomodidades a la empresa y el procedimiento respectivo de la gestión apelada, cuyo plazo será respondido dentro de 2 días.

Jul 20, 1960

By G. Goellner

The thick alluvial sand and gravel deposits along the base of the San Gabriel mountain range in Southern California area have been mined for construction aggregates for over 100 years. Encroachment of high-density urban populations in this area has led to concentrated mining in a handful of open pit mines with single production faces reaching up to 55 m (175 ft) in height, and long transportation distances from the pit to the processing plant. Aggregate producers have responded to these challenges by developing innovative mining systems which enable low-cost, full-face mining of the alluvial material, and low cost delivery of this material to the plant.

Jan 1, 2004

By Mehmet Guney

At the Armatcuk mine in Turkey, various modifications of sublevel methods have been tried during the last decade in an effort to eliminate gob fires, dangers from roof falls, and surface subsidence, and also to increase extraction efficiency. From the experience thus gained, it was decided that the most likely system to give maximum benefits, considering the existing geological conditions and coa1-seam characteristics, was hydraulic stowing. This paper examines trends in the working techniques of hydraulic stowing and discusses the favorable results and technical problems that the method produced at Armutcuk. The Armutcuk mine, a subsidiary of Eregli Coal Mines (EKI), produces 1300 tons of run-of-mine coal daily from thick (about 10-90 ft) and highly dipping (about 50-90°) coal seams. The coal is highly volatile with good coking properties that make it highly suitable for industrial use. Most of this coal is used in the iron and steel industry at Eregli on the Black Sea coast. Complete recovery of the coal is of vital importance to industrial development and progress. Initial coal extraction was carried out by means of a sublevel mining system modified to accommodate local geological conditions and coal seam characteristics. This method is similar to that employed in metalliferous mines. Several problems arose from the application of the method, one of them being the prevalence of gob fires which caused periodic shutdowns in some sections. To achieve maximum coal extraction with minimum dilution, to eliminate gob fires and surface subsidence, and to reduce fatal accident rates, a decision was taken to change from this method to a hydraulic stowing system. The pres- ence of large deposits of conglomerate and sandstone on the surface contributed to the decision to employ this new method. Although hydraulic stowing practices have been carried out in America and Germany, Upper Silesia may, so far as coal is concerned, be considered the birthplace of the method. Here the process was adapted to thick coal seams on a large scale to reduce dangers from gob fires and damage from surface subsidence. Today, the mining system is not only widely used in the coal mines of France, the Saar, India and Poland, but has also been successfully applied to the iron ore and potassium salt mines in Russia and Germany. LOCATION AND HISTORY The Kandilli-Armutcuk coal field, the most western outcrop of the North Anatolian coal basin, extends for five miles along the Black Sea coast (Fig. 1). The Armutcuk Mine is situated on the southern boundary of the coal field about 40 miles from Zonguldak and about 12 miles from Eregli. The history of coal mining in the North Anatolian coal basin goes back more than a century. Mining commenced on a small scale in the Kandilli-Armutcuk coal field in the late 1880's, and from this time until nationalization in 1940 the mines were operated by private Turkish and foreign interests. In 1940, Eregli Coal Mines was established to takeover the management of these enterprises. The Armutcuk Mine was developed for the first time in the mid-1940's. Since then it has been in continuous production and it now produces an annual 440,000-ton run-of-mine output from which 320.000 tons of salable coal is obtained. MINE GEOLOGY The carboniferous inlier of the Kandilli-Armutcuk coal field crops out over an area about three miles long and one mile wide. The major part of the inlier consists of the Namurian formation with only a relatively small area of Westfalian-A visible on the surface (Fig. 2). The Namurian formation, which has no exploitable coal seams in the Armutcuk Mine, consists mostly of arkose sandstones and black shales often having

Jan 1, 1969

By José María Lezcano, Diego Urquiaga, Pedro Delvasto, Marcos Garayar

La extracción de minerales ricos en sulfuros metálicos tiene el inconveniente de generar drenajes ácidos (AMD), los cuales causan severos impactos en los ecosistemas acuáticos, el suelo y el recurso hídrico. Como posibilidad de remediación (alcalinización) de estos pasivos, en el presente trabajo se propone el uso de coproductos férricos oxidados (CFO). Luego de presentar las características de un tipo de CFO específico, se muestran los resultados —a escala de laboratorio—sobre la respuesta alcalina del mismo, y se discuten las implicancias de estos hallazgos para el tratamiento de los AMD.

Nov 30, 2020

By Edmundo Alfaro, Álvaro Ordoñez

En el Perú existen diversos yacimientos mineros con contenidos de oro, plata y de metales base tales como el cobre, zinc, plomo, hierro, presentándose tanto como especies mineralógicas sulfuradas como de óxidos. En la zona sur del Perú se encuentran yacimientos de Zn–Pb–Cu–Ag–Au con depósitos híbridos de carbonatos y sulfuros masivos polimetálicos en rocas volcánicas. El tratamiento de este tipo de minerales presenta diversas dificultades para la recuperación de todos los metales de valor. En este sentido, se ha desarrollado investigación técnica preliminar utilizando el sistema peróxido de hidrógeno / amoniaco. (H2O2 / NH3); el peróxido actúa como agente oxidante y el amoniaco como agente acomplejante, dentro de una solución alcalina.

Sep 30, 2022

By Germán Alva, Camilo Ferreira, Rómulo Villegas, Franco Olcese

El siguiente documento presenta el caso de la realización de talleres participativos, voluntarios e inclusivos de consulta social con comunidades, centros poblados y ciudades del área de influencia directa e indirecta de Minera Yanacocha, en Cajamarca, Perú. El objetivo con estos talleres es conocer las percepciones y el sistema de creencias de la población con respecto a la minería y el impacto de estas creencias sobre la postura hacia la empresa, brindar información desmitificando mitos y midiendo la aceptación de la actividad minera.

Sep 30, 2022

During the last 20 years, more than 80 km (50 miles) of tunnels have been constructed in the Los Angeles, CA area. Recent projects include The East Central Interceptor Sewer (ECIS), completed in 2004. It spans more than 18 km (11 miles). The Northeast Interceptor Sewer (NEIS), completed in 2005, spans 11 km (7 miles). And the 2-km (1.3-mile) Metropolitan Transportation Authority?s Gold Line Eastside Extension (MCGLEE) was completed in 2006. All of the tunnel routes lay beneath heavily populated urban environments so minimizing ground surface settlement was critical to the success of the projects. Previous tunneling efforts in the Los Angeles area using open shield methods resulted in significant settlement that damaged roads, utilities, buildings and other structures. Earth pressure balance (EPB), or slurry machines, were specified for these projects to reduce subsidence risk. The contractors chose EPB tunnel boring machines (TBM) for the work. The closed and pressured face of the EPB TBM reduces loss of ground at the tunnel face and, when the machines are used in combination with gasketed pre-cast tunnel liners and backfill grout behind the installed segments, losses from over-cut of the excavated surface are also reduced.

Jan 1, 2008

By Gerhard Bischoff

El presente trabajo compara las contribuciones potenciales de las diferentes fuentes de energía primaria, es decir; petróleo, gas natural, carbón de piedra, lignito, fuerza hidráulica y minerales susceptibles a fisión nuclear, con el total de las existencias disponibles en el futuro.

Jul 1, 1970

By Daniel I. Carey

Current and potential dragline reclamation usage was evaluated for the U.S. coalfields based on data gathered and analyzed during field surveys, literature reviews and contacts with manufacturers. It was concluded that current wining plans have been adapted to federal and state strip mine and reclamation laws in ways which limit the potential for drag line reclamation systems at active mine sites. At abandoned conventional contour mine sites in steep-sloping areas such as central Appalachia, however, it was found that dragline reclamation systems have great potential application and may be the only practical solution to many reclamation problems. Alternative dragline systems were examined for restoring abandoned sites, and it was concluded that a tower excavator system offered superior characteristics and should be evaluated and developed under field conditions. A testing program was developed to provide a framework for the monitoring and analysis of cost, production and environmental data during a field demonstration of a tower excavator system.

Jan 1, 1981

By Lucas Hidalgo Quintana

El presente texto describe la mineralización de una de las estructuras mineralizadas de la mina Quiruvilca denominada la veta Papelillo. Para ello, se describe la fisiografía glaciar, la estructura mineralizada en volcánicos de la formación Callipuy del Cretáceo Superior a Terciario Inferior (mayormente de composición andesítica) intruida por pequeños stoks riolíticos, andesíticos y dacíticos. Asimismo, abundan la esfarelita, rubia, galena, marmatita en menor proporción enargita, rodocrocita y cuarzo. La caolinización es la alteración hipógena importante que ubica los cuerpos mineralizados, con texturas mayormente de relleno. Como controles estructurales, está la presencia de cimoides según el rumbo y buzamiento de la veta, la falla de relleno mineralizado fue normal con mayor potencia en los sectores de mayor buzamiento.

Nov 1, 1981

By Sheldon Wimpfen

La exploración es una actividad que utiliza la prospección geológica, prospección geofísica, sondajes, pozos de exploración o de sondeo, galerías de avance subterráneas, de superficie y socavone. Las etapas de la exploración se desarrollan en cuatro etapas : l evaluación regional, reconocimiento de áreas favorables, evaluación de superficie detallada de las áreas de objetivo. Asimismo, se describe la nueva técnicas de exploración y sus incentivos.

Mar 1, 1980

By D. T. Randall

The burning of coal without smoke is a problem that concerns the Government directly because of the advantages of smokeless combustion both in public buildings and on naval vessels. In addition, smoke abatement is a factor in conserving the fuel resources of the United States. Hence, as part of its general investigation of the best methods of utilizing the coals of this country, the Bureau of Mines, which is in charge of the fuel-testing work formerly carried on by the United States Geological Survey, has made extended tests to determine the conditions necessary for the smokeless combustion of bituminous coal in boiler furnaces. Bulletin 39,¢ a preliminary report, treats the smoke problem from a theoretical point of view, detailing the steps that are being taken by municipalities, manufacturers, and citizens to abate smoke, also showing the possibility of a clean city. The present bulletin not only shows that bituminous coals high in volatile matter can be burned without smoke, but also that large plants carrying loads that fluctuate widely, where boilers over banked fires must be put into service quickly and fires forced to the capacity of their units, can be operated without producing smoke that is objectionable. Proper equipment, efficient labor, and intelligent supervision are the necessary factors.

Jan 1, 1918

By G. C. Marino

The performance of the V-Day Mine near Danville, Illinois has been evaluated from data extending over about a 20 year period. The area included in this study involves over 16 acres. Essentially this entire area has progressively subsided. Extensive data has been collected on the geologic and mining conditions, the subsidence movements, as well as on the response of the surface structures to the subsidence. In this paper a detailed summary of the site conditions is given, and the mechanics of progressive failure of the studied room and pillar mine is postulated. These progressive long-term failures of the V-Day are then compared to other similar mine failures in Illinois. Some overall, but tentative, long-term strength evaluations are presented as well.

Jan 1, 1990

By Rajiv Kalra, Ji Jiangang

"This paper reviews the following aspects of the world’s largest manufactured Grinding Mill’s in terms of diameter and power, along with the world’s biggest shop assembly and trial run of the mills delivered to Sino Iron Magnetite Project in Australia.1. An overview of the basic flow sheet of the Sino Iron (Magnetite) Project located in Australia2. An overview of in-house designed CITIC Heavy Industries 12.2 m (40ft) F x 11 m(36ft) LG – 28MW AG mills including FEA and major components3. In-house manufacturing at CITIC-HIC work in Luoyang China of all major components for 6 off Ø12.2 m(40ft) AG mills and 6 off Ø7.9 m(26ft) x 13.6 m(44.6ft) LG – 2 x 7.8 MW Ball Mills4. Major aspects of design and preparation of the biggest shop trial run of Ø7.9 m(26ft) x 13.6 m(44.6ft) LG Ball Mill witnessed by international EPCM’s and clients in July 2009.5. Major aspects of one piece assembly of 1300 tonne rotating element of the Ø12.2 m(40ft) x 11 m(36ft) LG AG Mill and Ø7.9 m F (26) x 13.6 m(44.6ft) LG Ball Mill at the port of the export China and transport to Australian Port and then to site.6. An insight to unique installation methods used for Ø12.2 m(40ft) and Ø7.9 m(26ft) rotating element lifting on the mill foundation in one piece assemblies.7. CITIC Heavy Industries present capability for in house design and manufacture of Grinding Mills up to Ø13.7 m (45 ft) with 35 MW Gearless drives and Ø12.2 m(40ft) with 2 x 10 MW Geared Mill drives"

Jan 1, 2012

By Agustín Chang

La aplicación de las técnicas de Ingenieria Industrial en las minas de Centro Min Perú son importantes para ayudar a las operaciones para mejorar la productividad y reducir los costos. Los resultados obtenidos mediante los estudios de mejoras y de medición de trabajo, permitieron elevar la eficiencia personal y la óptima utilización de los recursos de operaciones de minas. En ese sentido, el presente texto busca proveer información relacionada con la práctica industrial en las minas de CentrominPerú a los ingenierios de Minas.

Nov 1, 1976

VOLUME III The objective of Volume III of this report is to provide a concise review of six major types of legal constraints, controls, and regulations on surface coal mining in the United States, as of January, 1976. At the same time, an attempt is made to format the details of federal and state exploration, mining, and reclamation regulations such that point-by-point comparisons can be made and updated as revisions occur. Thus, Volume III should provide both an executive overview and a user's manual of legal controls of surface coal mining.

Jan 1, 1976

By Rajiv Kalra

This paper reviews the following aspects of the world?s largest manufactured Grinding Mill?s in terms of diameter and power, along with the world?s biggest shop assembly and trial run of the mills delivered to Sino Iron Magnetite Project in Australia. 1. An overview of the basic flow sheet of the Sino Iron (Magnetite) Project located in Australia 2. An overview of in-house designed CITIC Heavy Industries 12.2 m (40ft) F x 11 m(36ft) LG ? 28MW AG mills including FEA and major components 3. In-house manufacturing at CITIC-HIC work in Luoyang China of all major components for 6 off Ø12.2 m(40ft) AG mills and 6 off Ø7.9 m(26ft) x 13.6 m(44.6ft) LG-2 x 7.8 MW Ball Mills 4. Major aspects of design and preparation of the biggest shop trial run of Ø7.9 m(26ft) x 13.6 m(44.6ft) LG Ball Mill witnessed by international EPCM?s and clients in July 2009. 5. Major aspects of one piece assembly of 1300 tonne rotating element of the Ø12.2 m(40ft) x 11 m(36ft) LG AG Mill and Ø7.9 m F (26) x 13.6 m(44.6ft) LG Ball Mill at the port of the export China and transport to Australian Port and then to site. 6. An insight to unique installation methods used for Ø12.2 m(40ft) and Ø7.9 m(26ft) rotating element lifting on the mill foundation in one piece assemblies. 7. CITIC Heavy Industries present capability for in house design and manufacture of Grinding Mills up to Ø13.7 m (45 ft) with 35 MW Gearless drives and Ø12.2 m(40ft) with 2 x 10 MW Geared Mill drives

Jan 1, 2012

The ready solubility of gold in dilute aqueous solutions of the cyanides of the alkalies or alkaline earths provides a convenient method for the separation of the precious metal -from the large surplus of associated materia1. The finely ground ore is pulped with a weak solution of cyanide, agitated to dissolve the gold, filtered and washed. The lowgrade filtrate is then clarified and the gold precipitated by some electronegative agent, the most usual being finely divided zinc or zinc dust. The slight precipitate is collectedon some form of filter coated with a filter aid, the filter cake being then known as "gold slime".A typical analysis of this slime is given in Table 1.

Jan 1, 1956

Since early July, domestic producer listings in primary aluminum ingot have been at 53¢ per pound. Dealers, however, lowered their August quotes by 1.8¢-2¢ to 47.5¢-48¢ per pound. BITUMINOUS COAL AND LIGNITE -The wildcat strike of UMWA coal miners which began on June 23 in protest of cutbacks in medical benefits appears to have ended. According to the West Virginia Coal Association on September 7, 1977, all mines in West Virginia were back in operation on September 6 and again on September 7. The Kentucky Coal Association reported approximately 2,500 miners were on strike in eastern Kentucky on September 6, but there was full employment on September 7.

Jan 1, 1977