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By V. A. Cooney

Introduction For the compliment paid me by the Institute's kind invitation to speak this afternoon, I am very grateful. For the astuteness of your officers in determining that encouragement should be given, through the medium of a paper, towards accident prevention in coal mines, the coal industry cannot but be grateful. Some day, and let us hope soon, a more developed paper may supersede this one. In the meantime, if some knowledge of what one coal field has been able to accomplish, even in the initial stages of its effort, will induce other fields and other sections of the mining industry to launch similar experiments, much good will result and a more developed dissertation on the subject will make its appearance.

Jan 1, 1946

By Félix Lewandowsky

El presente texto describe las actividades para corregir los pasivos ambientales heredados y asumidos bajo responsabilidad de la Compañía Minera Colquirrumi S.A. Para ello, se elaboró un plan de cierre de los cuatro depósitos de los relaves de Hualgayoc donde se busca mostrar los criterios utilizados, los estudios de ingeniería y la forma cómo se ejecutaron las obras de cierre definitivas de los depósitos de relaves.

Jan 1, 2015

By Juan Villanueva, Otto Sandoval

Antapite, en periodos anteriores (2001-2012), fue explotada con métodos de explotación subterráneos convencionales; sin embargo, este diseño tradicional era insuficiente para plantear un modelo económico sostenible sobre los escasos recursos geológicos, lo que motivó a la compañía Sierra Antapite a repensar el contenido del yacimiento que adquirió en el 2015. En el año 2017, Sierra Antapite empezó la rehabilitación de labores, con la finalidad de explotar vetas in situ, por el método de corte y relleno convencional. Asimismo, planea recuperar rellenos (para vetas explotadas anteriormente) por el método de taladros largos mecanizado.

Sep 20, 2019

By James F. O'Neill

Brown iron ore resources in Barbour , Butler , Crenshaw , and Pike Counties were investigated in a drilling program and geological study by the Federal Bureau of Mines in cooperation with the Alabama Geological Survey and the University of Alabama . The aggregate footage drilled was 18,010 linear feet . When developed , reserves of 12,664,000 long tons of crude ore were indicated , containing from 26.9 to 29.0 percent iron and 0.2 to 1.6 percent manganese under a maximum overburden of 40 feet . Total inferred crude ore for the four counties was calculated to be 827,700,000 long tons . Beneficiation of samples by simulated log washing and use of a 1 / 8 - inch screen yielded from 46.8 to 51.7 percent iron and 0.2 to 2.6 percent manganese . Screen- test studies indicated no appreciable interlocking between the iron and manganese minerals and the waste particles of materials retained on a 200 - mesh screen . Clay was prominent in micron - size slimes . Silica was deleterious in the minus 20 - mesh size . While an indicated 2,198,000 dry long tons of usable iron ore can be recovered , sink - and - float tests show that it may be possible for 4,654,000 dry long tons to be recovered by other than log washing . However , applicable commercial processes have not been demonstrated .

Jan 1, 1965

By Bujtor G. J, McMahon D. W

This guide to the understanding of ore reserve estimation is the revised version of a report with a similar title circulated within the CRA Limited (CRA) group of companies in mid-1980. It is the principal result to date of an Ore Reserve Study commissioned by CRA in late 1977.This guide to the understanding of ore reserve estimationis the revised version of a report with a similar titlecirculated within the CRA Limited (CRA) group ofcompanies in mid-1980. It is the principal result to dateof an Ore Reserve Study commissioned by CRA in late1977.The study was prompted by two ore reserve situations.The Zinc Corporation and New Broken Hill Consolidated,Broken Hill, had reached the point of havingto find a replacement 'for their traditional ore reserveprocedure and Mary Kathleen had to admit publicly thatore reserve predictions would not be realized. Thesewere not however the only problems to be looked at. Asmentioned more fully later, other ore reserve situationswere known, or were met during the study, in copper,gold and nickel as well, where poor realization: expectationratios had ranged from embarrassing to disastrous.These made it clear that ore reserve estimation had to belooked at afresh.The fresh look has resulted in a broadening of theconcept of ore reserve estimation from its traditionalpurely computational basis to an approach embracingall the many things that can affect expectation andrealization as essential factors. Hence this guiderepresents a gathering together of what has been learnedand what should be known to all those concerned withore reserves in any of its diverse aspects.The study has been marked"by a number of changesof thinking. At first the aspects that appeared to requireattention were two; recognition that an ore reserve statementwas an estimate, not a precise calculation; and asearch for im improved estimation procedure adapted tolow grade ores with narrow economic margins. Threeyears later the view was that the need was to incorporateinto ore reserve estimation all relevant aspects of theproposed mining operation from choice of a samplingmethod to sales contract specifications.This study is thought to be unique in being frankabout weaknesses in ore reserve estimation and intreating failures not as natural disasters (like drought orflood, which have to be endured) but as potentiallyavoidable. It has led to three principal conclusions.

Jan 1, 1982

By Walter Valery

Dado que el mercado de metales se hace cada vez más competitivo, se busca implementar nuevas tecnologías y metodologías más eficientes que aseguren la rentabilidad de la operación minera largo plazo. En ese sentido, el presente texto describe el procedimiento para iniciar e implementar el programa Metso Process Technology & Innovation (PTI) como parte de la metalurgia. Para ello, se describen los datos requeridos y la forma cómo deben ser evaluados e incorporados a los modelos GeoMetso. Así el programa surge como una alternativa costo-efectiva para ejecutar modelos geometalúrgicos de mayor precisión, de forma que se optimizen los resultados para las operaciones a lo largo del periodo de vida de la mina.

Mar 1, 2016

By John W. Taber

The Bohemia mining district is a small but intensely mineralized area in western Oregon . For its size , it has made a substantial although somewhat sporadic production of gold throughout a long period of years . The veins also contain lead, zinc , and copper, but in the past these metals have not been recovered in important amounts . In reviewing the progress of mining activity in the district , an effort has been made to gather under one cover all available information on former operations , including methods of mining , production, and geology pertinent to the ore deposits , problems encountered, and other factual data that may affect future mining in the district . A special effort has been made to assemble as many maps of former workings as possible in order that these may be preserved and readily available to assist in future exploration. The data presented herein are based on brief reconnaissance examinations made during several weeks spent in the field in September 1946. These are supplemented by information obtained from various individuals actively or formerly connected with operations in the district . Only the principal properties and several of the more outstanding prospects were actually examined. Many of the older workings were inaccessible.

Aug 1, 1949

"Horizontal grinding mills have been used in the mining industry for more than a century, and due to their operational and maintenance simplicity they remain a widely used technology for various stages of comminution. The relative ‘efficiency’ of horizontal grinding mills compared to other comminution equipment is often debated, and efforts to improve the energy efficiency of these mills is an on-going area of attention for process engineers.The discharge arrangement design affects the material transport characteristics within a horizontal grinding mill. Material transport plays a significant role on efficiency of horizontal grinding mills. The magnitude of benefits that can be achieved with efficient material transport in AG/SAG mills has been demonstrated in a Greenfield milling operation at Mirabela Mineração’s SantaRita Nickel operation in Brazil. This grinding circuit was commissioned in October 2009, which was designed as a typical SABC circuit to grind 4.6 mtpa (575tph) to produce a P80 of 125um with 10-12% ball charge in SAG mill. The nameplate design capacity has been achieved in few days in ABC circuit without grinding media in SAG mill, and has been operating in ABC mode. The through has gradually increased to an average of 800 tph and recently 7% ball charge has been introduced to increase the throughput to +900tph.This paper investigates improved material transport using Outotec’s TPL™ (Turbo Pulp Lifter) technology and the opportunities this technology presents when designing horizontal grinding mills. Operational data, with particular reference to energy and throughput optimization, is presented."

Jan 1, 2013

El siguiente estudio describe la relación del proceso de electrificación de empresas eléctricas asociadas (Lima, Arequipa), con la minería y la industria azucarera. De los tres campos mencionados, es la minería, la actividad que ha contribuido mayormente al proceso de desarrollo eléctrico (30%), y con el 50% en su aprovechamiento de potencial hidroeléctrico. Asimismo, las necesidades de electricidad para la producción de cobre, zinc y plomo son de 1, 800, 4600 y 450 Kw. -hr. por tonelada de mineral en las minerías del país, Cerro de Pasco y Junin, revelando un espacio de reserva de 600, 000 kw hasta el año de 1975. En este sentido, el proyecto hidroeléctrico del Mantaro, se considera como el sistema eléctrico más idóneo dentro del Plan de Electrificación Nacional, cuya producción alcanza 513,000 Kw. para la ciudad de Lima -en tanto fines de prestación de servicios púlblicos-, y se interconecta posteriormente con la costa norte del Perú. En consecuencia, la ejecución de esta primera etapa del Mantaro, permite alimentar al yacimiento minero de Cerro de Pasco, y al 90% de las minas de los departamentos de Junín, Pasco y Lima.

Jul 20, 1959

By Hassan Ghaffari

? HPGR Process/Overview ? HPGR vs. SAG ? The Manufacturers ? Mine Operations using HPGR ? Projects by Wardrop/Tetra Tech ? Economic Benefits ? Questions Main Operating Parameters ? Press Force (N/mm2) ? Roll Speed (m/s) ? Moisture Content (%) ? Feed Particle Size Distribution Specific throughput M* = throughput/D*L*V (ts/hm3) Flake thickness/strength in balance with the compressing force (floating roll situation)

Aug 1, 2013

By L. C. Graton

[CONTENTS PAGE INTRODUCTION AND ACKNOWLEDGMENTS. By George M. Fowler2 Question 1-Is Structural Deformation of Some Character Always Necessary for the Migration of Mineralizing Solutions, Especially in Limestone or Other Dense Rock? DISCUSSION by: A. M. Bateman 10 S. F. Kelly 15 C. H. Behre, Jr 8, 13 G. B. Langford 13 T. M. Broderick11 H. E. McKinstry6 R. H. Clarke 13 D. H. McLaughlin8 J. D. Forrester for M. H. Gidel . . . 4 W. H. Newhouse13 G. M. Fowler 2, 6, 11 R. H. Sales 6 L. C. Graton 11 Edward Sampson 12 R. D. Hoffman 10 J. S. Stevenson 7 I. B. Joralemon11 L. B. Wright 2 Question 2-What Are Some of the Chemical and Physical Characteristics in Certain Beds within a Limestone Formation that Determine Their Favorable or Unfavorable Aspects as Reservoirs for Ore and Other Introduced Minerals? DISCUSSION by: G. W. Bain 17G. M. Fowler 21 C. H. Behre, Jr21L. C. Graton18 J. S. Brown 16G. F. Loughlin18 E. L. Bruce 19R. H. Sales 19 R. H. Clarke 20A. K. Snelgrove 20 Question 3-Are There Any Criteria by Which One Can Determine When Mining Operations Have Reached the Roots of an Ore Deposit? DISCUSSION by: J. M. Boutwell29G. B. Langford 29 T. M. Broderick28G. F. Loughlin25 E. Y. Dougherty27R. H. Sales 24 G. M. Fowler 22F. A. Thomson 26 I. B. Joralemon 22Edward Wisser 30 General S. F. Kelly35 References36

Jan 1, 1940

By Matheus Teixeira Fraga

É comum o uso de modelos matemáticos no intuito de prever a qualidade do coque, sendo a maioria dos modelos atualmente disponíveis baseada nas propriedades dos carvões. Para este trabalho foram feitas misturas binárias e ternárias de carvões com variados teores de matéria volátil, a fim de se produzir coque em escala laboratorial. A reatividade ao CO2 em termobalança e resistência mecânica em tambores foi avaliada. Dois modelos para previsão de indicadores de qualidade do coque foram avaliados, o modelo aditivo e o modelo de interação. A partir da metodologia desenvolvida em laboratório foi possível produzir, avaliar e comparar coques feitos a partir de diferentes carvões e misturas. O modelo aditivo mostrou uma boa capacidade de prever a reatividade dos coques. No entanto, para os índices derivados dos testes de tambores os valores calculados mostram uma diferença importante em relação aos experimentais, indicando interação dos carvões no processo de carbonização. Nos resultados do modelo de interações, os valores calculados para reatividade e resistência mecânica, se comparados com os resultados do modelo aditivo, mostraram uma melhora na capacidade de previsão da qualidade do coque. O modelo de interações se apresenta como uma ferramenta interessante na seleção e mistura de carvões.

Aug 17, 2017

By Robert F. Mehl, Dana W. Smith

It has been shown that quenched iron of high purity exhibits a Wid-manstiitten figure much resembling martensite in appearance.1 This figure exhibits a maximum of four directions of the surface traces that characterize it, suggesting that a Fc forms from y Fe in plates parallel to the (III), octahedral, planes in the y lattice. Because of this, and also beqause of the general similarity to the structural appearance of martensite and to the Widmanstatten figure obtaining in slowly cooled hypoeutectoid steels it has been suggested2 that the orientation relationships obtaining between the y and a phases in pure iron are identical with those demonstrated in martensite3 and in slowly cooled hypoeutectoid steels,4 and indeed that the crystallographic mechanism of formation of a Fe from y Fe is the basic mechanism determining the orientation relationships found in both martensite and in slowly cooled hypoeutectoid steels. This paper will present experimental evidence in support of this view. Experimental Technique The analysis of the crystallographic mechanism of transformation in pure metals is beset with special difficulties, though some information

Jan 1, 1934

By Ruilin Yang

Blast vibration in the highwall from a cast blast in open pit mines or in the hanging walls from a stope blast in underground mines is a common concern. Vibration in such cases is a typical near-field situation where the distance from a blasthole to a point of interest varies significantly compared to the distance between the blast as a whole and the point of interest. Most existing blast vibration models are designed for far-field vibration using a single seed wave to represent all blastholes within a blast and do not simulate wave shape change over the distance. Using the site parameters from the analysis of signature hole vibrations, the present blast vibration model yields reasonable agreement with field measurements in terms of vibration amplitude and frequency. Case studies show that the model has been used successfully to assist field vibration control.

Jan 1, 2010

By J. W. Thompson

SALE AND CONVEYANCE. DEED BY INDIAN ALLOTTEE OF UNSOUND MIND-BONA FIDE PURCHASER. The deed of an Indian allottee whose mind was unsound, but who was not entirely without understanding, is voidable if made before the grantor's incapacity has been judicially determined; and a purchaser of the original grantee who interposes the defense of a bona fide purchaser has the burden of showing a purchase for value and on failure to do so can not claim the benefit of a bona fide purchaser. Adams Oil & Gas Co. v. Hudson (Oklahoma), 155 Pacific, 220, February. 1916. PURCHASER OF MINING CLAIM-RIGHT TO FIXTURES. The purchaser of a mine equipped with an electric hoist, placed in the mine under a rental contract with the owner of the hoist and under an agreement to return it to the owner at the expiration of the term of hiring, can not claim and hold the hoist as against the owner where the agent of the seller explained to the purchaser that the hoist was not owned by the owner of the claim. Montana Electric Co. v. Northern Valley Mining Co. (Montana), 153 Pacific, 1017. p, 1018, October, 1915. AUTHORITY OF GRANTEE TO EXTEND LEASE. A deed conveying lands subject to an oil and gas lease under which the lessee had the right to drill or pay money in lieu of drilling at his option, and reserving to the grantor a share of the royalties under such lease, and expressly authorizing the grantee to lease the land for oil and gas purposes and to take the rentals, authorizes the grantee to extend the existing lease before the expiration thereof in consideration of the annual payment of money in lieu of drilling, as contemplated by the lease.

Jan 1, 1916

By Cristhian Carrión

El trabajo evalúa la aplicación de la Inteligencia Artificial (IA) o Redes Neuronales Artificiales (RNA) en el procesamiento de minerales, con el fin de predecir y optimizar recuperaciones. El estudio describe el trabajo con variables diversas, el modelo de entrenamiento y aprendizaje supervisado, así como el nivel de exactitud en predicciones obtenidas con modelos tradicionales de progresión lineal y con una RNA entrenada (backpropagation).

Sep 20, 2019

In the past decade, the increased engagement of business in debates around sustainable development has prompted recognition of the importance of biological diversity at the local, national and global scales. Driven by increasing populations that demand rising real incomes, a range of human induced pressures are modifying natural habitats and diminishing their ability to support life. Public policy changes have struggled to arrest the loss of habitats such as wetlands or tropical forests, and the related extinction of plant and animal species. Although conservation legislation and regulation were once the exclusive responsibility of government, new partnerships are now being forged that increase the role of the private sector and non-government organisations (NGOs) in developing and delivering conservation initiatives. Since the mid 1990s Rio Tinto has had to adapt to meet the demands of a rapidly changing conservation landscape. When Rio Tinto adopted its statement of business practice in 1998 The way we work, it explicitly recognised the need to take account of relevant environmental factors in obtaining access to lands, particularly in designated areas of high conservation value. With the revision of The way we work in April 2003, the policy on land access was strengthened through removal of the word ?designated?, thereby signalling recognition of the importance of biodiversity outside of protected areas. In addition, Rio Tinto?s revised land access policy explicitly refers to the use of land that is surplus to operational requirements for habitat protection and biodiversity conservation, subject to social considerations. In late 2003 Rio Tinto further strengthened its commitment to biodiversity with the promulgation of its biodiversity strategy and related position statement, biodiversity principles? (See Appendix 1.1) and technical guidance documents. This commitment is also embodied in a variety of initiatives at the corporate and operational levels, which are reported on annually in Rio Tinto?s Social and environment review. This guide has been prepared to support the practical implementation of Rio Tinto?s biodiversity strategy. The purpose is to provide guidance on how to effectively integrate biodiversity into Rio Tinto?s operations. It is applicable to all Rio Tinto exploration, new development projects and operations, irrespective of whether they have been operational for some years or are at the beginning or end of their operational life cycles. This guidance has been developed to support the Rio Tinto Environment Standards and the Rio Tinto Community Standard and any additional supporting documents as they are developed.

Apr 1, 2005

By Beatriz Fausta Gandra

A chave para a operação eficaz de altos-fornos está em elevada produtividade, baixo consumo de combustível e maior liberdade na seleção de matérias-primas. Neste contexto, foram realizados testes de caracterização e comportamento a alta temperatura de diferentes combustíveis para verificar sua potencial utilização sob a forma de small nos altos-fornos. Foi verificada, em escala piloto, melhoria considerável dos resultados para todos os combustíveis analisados em relação à condição de 100 % de sínter na carga metálica. O uso de 5 % de small indica considerável ganho em termos de permeabilidade e redutibilidade, com limite superior em 10 % de small para uso em altos-fornos. Modo geral, o carvão vegetal foi o material de melhor desempenho, seguido pelo coque e coque verde de petróleo. O antracito foi o combustível de pior desempenho sob a forma de small dentre os avaliados. Em relação ao modo de carregamento, é evidente a necessidade de se distribuir o small em meio à carga metálica para se absorver ao máximo seu potencial de melhoria da permeabilidade e da redutibilidade do leito no interior do alto-forno.

Aug 16, 2017

By Marcelo Ito

Este artigo pretende apresentar a solução adotada para aumentar a disponibilidade da planta de moagem de carvão em 6,6% na unidade Barro Alto, membro do grupo Anglo American Brasil, substituindo o combustível utilizado no Gerador de Gás Quente (GGQ), com ganhos de R$ 161.000,00 por mês. Motivado pelas complicações técnicas envolvidas no uso de óleo combustível pesado, como a baixa confiabilidade do arranque do GGQ, falhas constantes no ignitor, baixa eficiência de queima, alta geração de CO, incrustações de cinzas a jusante do equipamento, além dos impactos frequentes na estabilidade do perfil térmico dos fornos rotativos devido à falta de carvão pulverizado para os queimadores, aos riscos de segurança associados aos procedimentos de limpeza das cinzas e à redução no tempo de vida dos componentes periféricos como refratários, mangas do filtro e instrumentos. No final do estudo, a aplicação de um novo queimador de GLP levou aos resultados mais rentáveis.

Oct 30, 2017

By Enver Alan, MerkeziYapı

People are migrating because of economic, social, natural and political reasons. These natural and humane factors effects the distribution of populations. The need for tunnels has grown in order to provide a comfortable life and reduce losses such as waste of time, labor, energy, efficiency and so on. It is inevitable to carry out excavations in rock tunnels (shears, platforms, lines, connections, wastewater, distribution, energy, transportation etc.), that will be built by excavating with conventional method, by controlled blasting regarding with constrains. In this study of applied explosives engineering the blasting applications are evaluated, which were carried out for research and development purposes at Yenisahra Station tunnels in Kartal Formation which was built with the aim of solving İstanbul's transportation problem within the framework of the Kadıköy-Kartal Metro Project. Twenty-four shots were made by using explosives in 60 blastholes that were drilled in the tunnel faces, which were located between and outside of two different faults. Six microphones were used to measure the air shock and eight geophones were used to measure the parameter values of the vibrations (particle velocity, frequency, displacement, acceleration, amplitude, wavelength etc.), which were placed at predetermined points of the surface, occurred during the blasting applications. Data from the geophone and microphones were recorded on six seismographs. The coordinates and the distances between the shot points and the measurement stations are determined by an electronic theodolite. The total number of seismic records, recorded in seismographs, is 118. The number of records of vibrations that crossed the faults is 42 and the number of records of vibrations that did not cross the fault is 76. The particle velocity, frequency, amplitude, acceleration, displacement and wavelength were measured in transverse, longitudinal and vertical directions. The total number of measurements is 354. By evaluating all seismic records, the effect of delay intervals, faults and scaled distances on the particle velocity, frequency, amplitude, displacement, acceleration, wavelength and air shock were investigated. When the vibrations formed during the Research & Development (R&D) blasts were examined, it was determined that the parameter values of vibrations that crossed the faults are lower than the ones that did not cross the faults. In addition, when the particle velocity values of all vibrations are examined according to the present circumstances, it is determined that the waves did not cross the fault in all delay intervals are superposed in all directions, and that the least superposing occurred in the 50 ms delay range.