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By James R. Jones

It has been 2-1/2 years since the Congress passed the Surface Mining Control and Reclamation Act of 1977 (PL95-87) the Office of Surface Mining every deadline specified in the Act. Hopefully the Congress will begin to realize that specifying unrealistic deadlines does not accomplish the end desire of legislation any sooner -- it only adds to the confusion, and actually hinders orderly, efficient progress. OSM has been sued by all categories of involved parties -- environmental activitist organizations, the states, and the coal operators. This situation has resulted for two reasons: (1) insufficient time was allotted by the Congress to properly develop the regulations and program, and (2) OSM?s philosophy that it must dictate every detail of reclamation operations from Washington, even though many of its people are inexperienced with coal mining. These law- suits are now demonstrating their value. OSM is showing signs of "pulling-in-its horns" and, hopefully, will approach the revised regulations in a more realistic fasion.

Jan 1, 1980

By William D. Southard, Joseph W. Schlitt, Bruce P. Ream, Lawrence J. Haug

The operation of Kennecott 's Bingham Canyon copper precipitation plant, one of the world's largest, is described. This description includes a brief historical review of precipitation at Bingham and the general layout and operation of the present cone cementation facility. Current practices are based on results of studies undertaken to define improvements needed in each unit operation. These improvements were required to meet changing plant conditions and were implemented primarily within the constraints of the existing facilities. Specific unit operations included were the cone precipitators, the cone discharge thickener, the cone effluent settling basins, and the plate and frame filter presses. As a result of these improvements, loss of precipitated copper decreased and the degree of precipitation increased, raising copper recovery by 9 t/d. At the same time, iron consumption was reduced by 22.5 t/d. Problems in drying the cement copper were also overcome so that a product containing 12-15% moisture could be consistently delivered for smelting.

Jan 1, 1980

[CONTENTS COUNTY NO. OF MINES MINE INDEX PAGE]

Jan 1, 1980

By J. Clark

The objective of this study has been to determine the state of the art in underground, thin-seam-mining systems, to identify new technology and procedures that would reduce the hazards of thin-seam mining and to recommend areas for further research. The study was carried out in two phases, the first of these being devoted to a survey of authoritative literature. Subsequently, the practices adopted in the various mining countries were analysed and comparisons made to identify machines and methods with the potential for application in the USA. Published figures on US bituminous coal reserves show the high proportion contained in thin seams and US accident statistics demonstrate that the risk is greater in thin-seam operations. A comparison has been made with the experiences of foreign operations. The Phase 11 study proceeded along two separate avenues to examine the distinctive problems associated with seam thicknesses above and below 30 in. Current systems of mining appropriate to seams greater than 30 in were elaborated and compared by means of a simulation exercise in terms of safety, production and cost. For seams below 30 in, less conventional systems, some presently disused, were studied and their potential evaluated; the research and development work necessary to make them viable has been indicated.

Jan 1, 1980

By David Bendersky

The principal objectives of this study are to: (1) survey electrical practices in metal and non-metal mines, (2) survey electrical practices in metal and non-metal mills, (3) clarify the federal regulations governing electrical practices in metal and non-metal mines/mills, (4) analyze electrical accidents, and (5) make recommendations aimed at improvement of the safety of electrical practices in metal and non-metal mines. Information was obtained from literature searches, accident reports, visits to 27 mines and 12 mills, and discussions with knowledgeable industry and government people. The various electrical power systems and practices at the mines and mills visited are described. Similarities and differences based on the type of mining and the minerals being mined or milled are presented. The federal regulations governing metal/non-metal mine/mill electrical practices (Code of Federal Regulations, Title 30, Sections 55.12, 56.12, and 57.12) are presented and discussed. Explanations of each regulation are provided in an appendix. The attitudes of mine/mill operators towards the federal regulations are described. An analysis of the electrical accidents in metal/non-metal mines and mills during the period 1972-1978 is presented. Recommendations, including specific research and development activities, aimed at improvement of electrical safety in metal/non-metal mines are submitted.

Jan 1, 1980

By Robert S. Becker

The results of a laboratory investigation of coal cutting mechanics and noise is presented. These experiments were performed using a linear cutting apparatus that operates over a broad cutting speed range. The influence of several coal cutting parameters on the noise, force, productivity, and specific energy associated with linear cuts is ascertained. Some basic theoretical aspects of coal cutting mechanics and noise generation are discussed, and the results of the laboratory experiments are used to Formulate analytical models of the coal cutting forces and noise. The analytical model For coal cutting noise is then generalized to account for the more important effects of rotary cutting. Based on the generalized model, an estimate of the sound pressure level at an operator's position is made for a typical continuous mining machine. It is concluded that by employing linear rather than rotary cuts, using deeper depths of cut, slower cutting speeds, and more efficient cutting tools, it is possible to reduce the level of coal cutting noise, as well as Provide benefits to other important areas of underground health and safety.

Jan 1, 1980

By R. A. Meister

The study on improving surface coat refuse disposal site inspections included surface inspections of 15 refuse disposal sites. Monthly aerial photos were taken of the sites and computer methods were used to determine elevation changes. Photogrammetric techniques that were used are described in detail. A comparison of the results of each of these inspection techniques is included. A detailed evaluation of the photogrammetric techniques was made and conclusions were drawn concerning the advantages and disadvantages of using aerial photography and photogrammetry as part of the inspection procedure. Operators' opinions of the aerial photography methods are included.

Jan 1, 1980

By Jeffrey S. Newman

This report establishes a methodology for the evaluation of gas detection devices and is the result of a critical investigation into the basic principles defining gas detector performance. A scheme is presented to evaluate the performance of a test sample of gas detectors based on the detector type and intended application. Test procedures, worksheets, test apparatus, glossary and statistical methods for handling test data arc given. In addition, evaluation standards and test parameters are identified. It is intended that this report serve as a comprehensive framework for the eventual certification of all gas detectors for mine applications. A plan is proposed and recommended for the quantification and implementation of evaluation standards for gas detection device certification.

Jan 1, 1980

By Kato T, Eguchi M, Seino T, Itagaki K, Kimura T, Muto T, Shimizu T, Kobayashi T

Behaviour of minor elements in the dust collecting system connected with fluidized bed roaster for zinc concentrate was investigated by use of the bench scale experimental appara- tus. The dust collecting system was consisting of two dust chambers, hot electrostatic precip- itator, washing tower, mist electrostatic pre- cipitator, drying tower, absorption towers and potassium permanganate solution towers. Some volatile elements such as lead, cadmium and arsenic tend to concentrate in the fine calcine obtained in hot electrostatic precipitator especially in the case of the roasting with insufficient air supply. Special attention was paid to behaviour of mercury. In the roasting tests for plain zinc concentrate, it was considered that most mercury volatilizes at first as elemental vapour in the roaster, but with decrease in temperature of gas around a half of mercury forms compound, and both elemen- tal and compound forms of mercury were found in the gas stream. Elemental mercury is of course difficult to be trapped in the dust collecting system. To promote the compound formations, some additives for concentrate, such as selenium and halogens were effective, especially selenium of a few times equivalent to form HgSe repre- sented complete conversion of mercury from elemental to compound. To clarify the behaviour and removal mech- anism of mercury, various small scale laboratory tests were also carried out. It was confirmed that mercury sulfate formation is possible if temperature and flow rate are adjusted adequate- ly for gas stream consisting of 02-SO2-N2. To trap elemental mercury, various substances were tested, and excellent results were obtained with selenium. Satisfactory results were obtained with a selenium disc heated at 100 to 200¦C in a mercury containing gas stream. Also, applica- bility of scrubbing method with SeO2 solution was investigated, and the solution containing a few hundred ppm SeO2, 0.01 per cent additive and 6 per cent H2SO4 proved to be satisfactory.

Jan 1, 1980

By Iwu GO, Almond DP, Joasoo _

The gravimetric integral Knudsen effusion method was used to measure cadmium activity values in binary liquid In-Cd alloys in the range 523 to 573 K. The activity measurements together with other studies from the literature indicate that special bonding conditions exist in the melts near a composition corresponding to InCd3. Sound velocities in In-Cd melts were also measured using a precision pulse-echo over- lap method in the range 404 to 953 K. The frac- tional deviation of experimental and ideal isentropic compressibilities at 623K shows a functional dependence on composition with a pronounced maximum near the composition 75 at.%.

Jan 1, 1980

By Wm. L. Giachino

"Over the last 10 years, C-1-L has played a significant role in the major advances that have taken place in blasting technology, among them the following: development and introduction of capsensitive slurries; development of bulk slurry systems both for underground and open-pit operations; development of the TOE-DET and ANODET systems of delay blasting;introduction of the NONEL system of initiation;development of the Vertical Crater Retreat (VCR) system of mining.This paper identifies areasin which we foresee further developments in blasting technology over the next 10 years and outlines how and to what extent C-1-L will become involved."

Jan 1, 1980

By Stanley W. Ivosevic

The South-Central Osa Peninsula produced around 30,000 kg (100,000 troy oz) of gold since prehistoric times. Gold freed by erosion from quartz lodes in the Mesozoic Nicoya ophiolite complex was reconcentrated through three generations of Quaternary sedimentary deposits. Resultant gold placers grade upward from 1 g/m3 (0.03 troy oz/m3) and are of moderate size.

Jan 1, 1980

By Glenn Buchana

El presente texto señala algunos aspectos técnicos y comerciales del dragado del depósito fluvial. Para ello, es necesario conocer el origen y desarrollo del depósito fluvial. El depósito fluvial es una masa de grava superficial, la cual es producto del desmoronamiento y erosión de rocas sólidas que contienen partículas o pepitas de oro, diamante, estaño, platino u otros minerales valiosos que proceden de las rocas o de las vetas. Entre los tipos de depósitos aluviales tenemos: depósitos aislados pequeños y poco profundos, los depósitos de mediana profundidad, depósitos profundos y los marinos. La explotación se realiza a través de tres sistemas: draga cortadora de succión, la dragalínea de cangilones y la planta de tratamiento flotante.

Nov 1, 1979

By Felipe De Lucio Pezet

El presente texto es un recuento de acontecimientos importantes ocurridos en el distrito minero de Morococha desde la época precolombina hasta 1940, de forma que contribuya al desarrollo de la historia minera del Perú.

Nov 1, 1979

By Guillermo Florez Pinedo

El presente texto es un análisis del aspecto económico y social de la minería en el Perú, así como sus efectos en el sector industrial. Para ello, se revisa la producción minera de los cinco metales más importantes del país tanto por su volumen como por el valor de su venta: cobre, plomo, zinc, plata y hierro, la contribución de esta actividad en el desarrollo nacional , industria nacional, las reservas, plan de desarrollo minero y las perspectivas para la industria nacional.

Sep 1, 1979

By Juan Languasco de Habich

El presente texto señala la situación actual de la pequeña minería, así como las ventajas, decreto ley 18880, garantía, reservas, requisitos, características del financiamiento, crédito minero, rol de tasa, modalidades del crédito minero, y las fuentes de financiamiento para la pequeña y mediana minería.

Sep 1, 1979

By Jorge Acuña de la Fuente

El presente texto describe el estado actual de la fabricación del coque y del carbón como uno de los elementos químicos y fuentes de energía más importantes que intervienen en la industria siderúrgica peruana. El carbón se explota en la mayor parte de las naciones del globo. Sin embargo, una cantidad apreciable de países productores no logra satisfacer sus propias necesidades y depende en mayor o menor escaia de la importación. Con el fin de garantizar los suministros de importación, se ha generalizado la práctica de celebrar contratos a largo plazo, iniciada por los grandes países consumidores. De otro lado, el coque, es el producto residual de la destilación seca de carbones bituminosos, cuyo elevado costo ha orientado los estudios técnico-económicos sobre su elaboración hacia dos objetivos fundamentales: en primer lugar, la optimización del proceso clásico de coquificación, al desarrollar paraielamente nuevas técnicas del carbonización, y por otra parte, la variación de las fundiciones en el alto horno en pro de un menor consumo específico de coque, ya sea por reemplazo parcial de éste por otros elementos reductores, o nuevos artificios de operación.

Jul 1, 1979

By Jorge Vargas Fernández

El presente artículo describe los aspectos técnicos, folklóricos y tradicionales que comprende la minería boliviana, particularmente Potosí y Oruro. El nombre de Potosí deriva del término quechua "sumaj orcko" que significa "cerro hermoso" y se remonta al siglo XVII donde fue considerada como la ciudad más grande del continente americano. Asimismo, se edificó sobre las ciénagas del Photoj Unu donde para desecarla, se construyeron los mitayos, una ancha y profunda zanja conocida con el nombre de QUINTUMAYU. Para ello se gastó parte de los "quintos reales", que eran los impuestos de la quinta parte sobre lo que producía el cerro y cada minero pagaba en beneficio de la Real Hacienda. Posteriormente, la construcción de calles y plazas se realizó sin allanar las escabrosidades del subsuelo, donde no se consideró un sentido estético, conviritiéndose en un laberinto de calles estrechas y desordenadas. En 1572, se construyó la primera casa de amonedación y se realizaron festividades como la del Corpus Finalmente, la minería boliviana se dedica a trabajar estaño, wolfram y en menor proporción .antimonio, plomo, zinc y plata, donde exsite poca inversión extranjera debido a problemas políticos y la mediana y pequeña empresa es de propiedad total de los bolivianos.

May 1, 1979

By Robert Sundeen

En el marco de la minería subterránea, el uso de máquinas sin rieles y con motores diesel fueron el último avance tecnológico en la explotación de minas. Sin embargo, Finley desarrolló una una pala cargadora neumática con el objeto de cargar pequeños carros mineros montados sobre rieles. El cargador fue usado durante 35 años como el método principal de carga mecanizado en minas subterráneas y se optó por el uso de motores diesel como el único combustible usado con motores a combustión interna en máquinas de minería subterránea, dado que tiene menos riesgo que los motores a gasolina dentro de la mina. En ese sentdo, el presente texto describe el concepto, uso, sistemas atípicos de las máquinas sin rieles. Asimismo, se refiere los factores que influyen el diseño de minas y sus efectos en las máquinas y la comparación de métodos mineros en mina con y sin sistemas de rieles.

May 1, 1979

By G. Melcher

"A través de la introducción del proceso de flotación, el horno de cuba perdió su importancia como unidad de fusión en la metalurgia del cobre. El producto obtenido mediante este proceso de tratamiento de minerales constituye un concentrado de flotación de granulometría extremadamente fina. En ese sentido, el presente texto señala un proceso de fusión en el cual el combustible natural del concentrado: el azufre, se utiliza para el trabajo de fusión. Asimismo, la tostación y la fusión se realizan en una sola unidad de horno y la gran superficie natural del concentrado de flotación, se aprovecha para la fusión, de modo que el concentrado sea tostado en suspensión y al mismo tiempo, fundido. Finalmente, la cantidad de los gases que reaccionan con los sólidos, puede aumentar considerablemente y, por lo tanto, igualmente la velocidad de reacción. "

May 1, 1979