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By Danny Valencia, José Olaechea

Desde el año 2014, Compañía de Minas Buenaventura (Buenaventura) viene ejecutando el programa de desarrollo productivo y articulación comercial PRA – Buenaventura (PRA BVN), que contribuye a mejorar la calidad de vida de miles de familias de las comunidades vecinas a nuestras operaciones. El programa está diseñado para fortalecer las iniciativas y actividades económicas locales articulando la producción al mercado y generando emprendimientos competitivos y sostenibles. El PRA BVN facilita una relación de armonía y confianza que contribuye al desarrollo de las comunidades y a la sostenibilidad de las operaciones de Buenaventura.

Sep 29, 2023

By Julio Solano Sáez

El presente texto refiere la programación anual de la producción realizada en la mina Quiruvilca, donde se realizaron ajustes de dicho programa a través de la generación de datos, la capacidad de instalación de equipos y las condiciones de rendimiento de los mismos. Posteriormente, se analiza algunos factores directos e indirectos que influyen en la producción, así como se realiza una mezcla de mineral que proporcione una contribución máxima y se evalúa el tiempo de acuerdo a esta producción.

Nov 20, 1978

By F. Robert Hollo

Programmable controllers have achieved remarkable acceptance over the relatively few years since their introduction. They provide some unique advantages over conventional relay and solid-state logic, which they often replace. Programmable controllers are discussed in both conceptual and functional terms, followed by an exploration of their applicability to material handling tasks with particular emphasis on conveyor systems.

Jan 1, 1973

By John J. Sammarco

Abstract- Emergency shutdown systems (ESDs) for mining machinery provide critical functions to safeguard miners. Traditionally, ESDs were realized with simple hardwired circuits; today, there is a growing trend to use programmable electronic technology such as programmable logic controllers (PLCs). This paper describes an analytical study to quantify the safety integrity of a PLC-based ESD and a hardwired ESD. The safety integrity level of each design approach was determined by quantifying the average probability of failure on demand (PFDavg) as described by the recommendations for programmable electronic mining systems published by NIOSH and the IEC 61508 international standard. The safety analyses addressed system architecture, hardware failure probability, proof test interval, diagnostic coverage, and human error probability. The results indicated that a same level of safety, safety integrity level 3 (SIL 3), could be attained when evaluating random hardware failures. Neither approach could attain SIL 3 if manual activation was used. Human error was the limiting factor where, using human reliability analysis, PFDavg < 1 x 10-1; thus, the ESD does not meet SIL 1. It is apparent that automatic verses human¬activation of the ESD is a very important safety consideration. Manually actuated ESDs can only achieve SIL 1 regardless of the technology; therefore, additional independent safety layers of protection are needed to exceed SIL 1. Secondly, it is apparent that the technology choice is very important. The PLC-based ESD was much simpler to design and to validate safety1.

Jan 1, 2007

By L. W. Krahenbil

The programmable Logic Controller (PLC), at its present stage of evolution, is now considered as a mature control system. The PLC combines the solid-state reliability of hardwired logic and computer control systems with the simplicity of a relay ladder logic. Relay symbolic programming through a function-oriented keyboard provides a means which plant personnel can easily become accustomed to work with. In a large coal facility, it is shown that the control engineer can provide improved control flexibility with the advanced capabilities of the PLC.

Jan 1, 1979

By Jean-Luc Cornet

As modern conveyors are increasing in size and complexity, their control requirements are becoming more and more critical. In addition to the safety and equipment protection requirements, control systems are now called to implement intelligent drive controls derived from dynamic analysis modelling, as well as to provide fast and accurate diagnostics while keeping operator controls simple. These requirements led to the development of a new and innovative approach to control system development. This paper describes the control philosophy used by Conveyor Dynamics, Inc. (CDI) and some of the key features of our approach to the architecture of control systems.

Jan 1, 1993

By Mike Horn, Keith Meade, Marvin L. Smallwood

Technological changes in programmable logic controllers (PLC)&apos;s and the need to improve the architecture of Mine Wide Monitoring Systems (MWMS) has resulted in the design of a PLC based system at the Virginia Division of Island Creek Coal Company. The system which is presently in the installation phase, is a joint effort of Island Creek Coal Company, Westinghouse Electric Supply Company and Mining Controls Incorporated. The system uses an ethernet based network for graphic display of system data operating under the Genesis software package. Telemetry for the system utilizes the Seimens/Westinghouse L1 network operating over two twisted pairs. Remote telemetry uses fiber optic links and modems operating over standard telephone lines. 500 and 2000 series PLC&apos;s provide distributed data processing for the system with hierarchial processing operating under the Genesis software on the ethernet network for individual mine site monitoring along with the remotely located division office monitoring. System control and data acquisition is provided for underground MWMS operations and on the surface for a vast methane gathering system that is used for degasification of the mines and collection of pure methane for sale to the Columbia Gas Company as natural gas. The inability of industrial MWMS companies to keep up with the vast changes in technology, along with economic considerations associated with expanding the existing MWMS created the need for the development of the PLC based system to replace the older industrial monitoring systems.

Jan 1, 1993

By Robert G. Paul

President Reagan&apos;s Exclusive Economic Zone (EEZ) Proclamation of March 10, 1983, extended United States ocean jurisdiction 200 nautical miles offshore our coastal states and territories. The accompanying policy statement noted that this action was a result of recently discovered deposits of polymetallic sulfides and cobalt-rich manganese crusts, which could be a major source of minerals important to the U.S. economy and security. Within these 3 billion acres of exclusive economic jurisdiction, the United States has sovereign rights to explore, develop, conserve, and manage the mineral and other natural resources of the seabed. The President has directed the Department of the Interior (DOI) to encourage exploration and production of minerals from this area. The DOI, through the Minerals Managment Service (MMS), is responding to this presidential directive by developing a leasing program for nonenergy minerals in the EEZ. The authority to develop this leasing program is the Outer Continental Shelf Lands Act of 1953, as amended in 1978, which authorizes the Secretary of the Interior to grant leases for oil, gas, sulfur, and other mineral resources on the Outer Continental Shelf (OCS). The Solicitor of D01 has determined that the definition of the OCS for legal purposes extends at least 200 nautical miles offshore of our coastal states to the EEZ boundary. Section 8 (k) of the Act allows the Secretary to lease minerals, other than oil, gas, and sulfur, on the basis of competitive bonus bidding and under such terms and conditions as he may prescribe at the time of offering the area for lease.

Jan 1, 1985

En quoi consistent les études de suivi des effets sur l?environnement (ESEE)? Les ESEE constituent une méthode de suivi scientifique que l?on peut employer pour déterminer la santé des écosystèmes aquatiques (qui peuvent être touchés par l?activité humaine) et l?efficacité des mesures de protection de l?environnement. Les ESEE sont des évaluations scientifiques itératives du poisson, de l?habitat du poisson et des ressources halieutiques. Le programme comporte des phases séquentielles de deux à six ans de suivi, d?interprétation et de compte rendu au cours desquelles la fréquence et le type de suivi dépendent des résultats des études précédentes. Le programme des ESEE pour les mines de métaux est fondé sur un accord conclu à l?unanimité entre les intervenants. Les exigences du programme et les guides techniques connexes ont été élaborés à la suite d?une consultation multilatérale à laquelle ont participé les représentants du secteur privé, du gouvernement et des collectivités. Toutes les mines assujetties au Règlement sur les effluents des mines de métaux (REMM), aux termes de la Loi sur les pê ches, doivent procéder à une ESEE dans le cadre de l?autorisation qu?ils ont reç ue de rejeter des effluents. Le REMM a été enregistré le 6 juin 2002 et publié dans la Partie II de la Gazette du Canada le 19 juin 2002 (SOR/DORS/2002-222).

Nov 1, 2002

In 1973, US Borax & Chemical Corp. began investing three days wages and about $20 in training materials in every new employee before having him report to his first job. The result? Accidents involving new employees in the past two years have dropped by more than half from the 1972 level. What made this success possible was safety training done with programmed instruction materials-which, incidentally, US Borax also uses for vocational training.

Jan 4, 1976

By C. S. Gibson

INTRODUCTION I WELCOME the opportunity to speak on Programmes in Safety. The invitation to do so shows that those guiding affairs of the Institute in this District realize the practical importance of this subject. My remarks are intended primarily for mines having 100 to 400 employees, approximately. With minor modifications, however, they apply also to larger or smaller operations. Others, I hope, will derive benefit from this paper, for they, too, have a part to play in accident prevention; for example, contractors such as shaft-sinkers; manufacturers of equipment; and consultants and designers of mining, milling, and metallurgical methods. These troubled times stress, as never before, the importance of efficient operations in mining. The days are gone when neglect can be afforded. Safe working conditions and satisfied employees are essential for efficient production at reasonable cost. The mining industry of Ontario long has been keenly aware of the human aspects of this subject, and as a whole it has done much to decrease the frequency and severity of disabling accidents. The number of fatalities per 1,000 employees has been reduced from a high of 5 some two decades ago to an all-time low of 0.89 in 1948; the incidence was slightly higher in 1949, being 1.17 per 1,000. The reduction in non-fatal compensable accidents also has been outstanding, frequency having ?been reduced from over 200 per 1,000 employees some two decades ago to 54 per 1,000 at the producing mines in 1949. These statistics demonstrate progress. Nevertheless, the general picture still leaves much to be desired when viewed from two other angles.

Jan 1, 1951

By C. W. Merrill

Minerals research by the U.S. Bureau of Mines embraces the mining and metallurgical problems of some 80 metals and nonmetals excluding the mineral fuels. It requires the energies and talents of about 1400 persons, almost half of whom are professionally trained in the physical sciences or engineering. Of approximately $13 million appropriated to the Bureau for minerals programs in Fiscal Year 1962, 76% has been allotted to technologic research and 24% to resources examination and appraisal. In addition, almost $2 million will be made available to the Bureau for minerals research from other Government sources and from private organizations that wish to utilize Bureau experience and capabilities in cooperative studies.

Jan 11, 1961

By Dilip Banerjee

"This paper discusses the Advanced Technology Program (ATP)'s support over the last decade to the development and use of process modeling as a tool to address some of the challenges faced by the U.S. metal casting industries. A particular focus will be given to highlight how process modeling can be used to improve the manufacturability of components needed for high performance and critical applications. The challenges associated with the design and production of thin-walled, cast parts with intricate and complex internal geometries will be discussed. Modeling issues associated with the control of the final grain structure in the solidified parts will also be addressed. This paper will describe the advantages of using appropriate mathematical models for designing new alloys for use in various applications.Finally, the role that ATP has played in uplifting the U.S. technological base through partnerships with industry and academia in high-risk research in order to bring to market new and improved products for the broader benefit of the nation will be discussed.ATP's BackgroundIn the 1980s, U.S. industries were losing market share to low-cost, high-quality manufacturers from Asian countries. Corporate leaders and policy makers determined that in order to sustain and grow market share, U.S. industries needed to improve their competitiveness and productivity through product and process innovation. There was evidence that companies were systematically under-investing in leading-edgetechnologies and failing to complete the development of new technologies [l]. There were also arguments in academic circles that pointed to a potential market failure in the area of early-stage technological developments. These concerns provided impetus for creation of the Advanced Technology Program (ATP) within the National Institute of Standards and Technology through the Omnibus Trade and Competitiveness Act of 1988. Through a rigorously competitive, cost-shared partnership with industry, ATP fosters the development and broad dissemination of high-risk technologies that offer the potential for significant broad-based economic benefits to the United States."

Jan 1, 2004

By Gago P. Oliver

El origen del sostenimiento con pernos para roca se remonta al inicio de la década del 70, donde el uso inicial fue a través de varillas "L"de diámetro de ranura a un extremo introducido a una cuña. El requisito para el desempeño del perno fue contar con un hueco de perforación a la medida y una roca competente para este fin. Posteirormente se realizaron otras pruebas para determinar la capacidad de anclaje de la roca encajonante como de las vetas de l/8" de diámetro con "mariposas" a un extremo como medio de anclamiento. En este sentido, el texto señala que el uso de tubos para el yacimiento de Quiruvilca es favorable, en comparación a los pernos, puesto que mejora el rendimiento y seguridad de la mina, aunque su adquisición sea costosa. Mientras que desde la perspectiva de la mecánica de rocas, el método de reforzamiento es el más efectivo ya que actúa contra la totalidad de la superficie del hueco.

Nov 8, 1984

By S. Saluja

El presente texto describe las aplicaciones de los pernos de roca como un sistema de sostenimiento en la minería. Asimismo, se comparan los distintos tipos de pernos de roca, se muestran los pernos de roca de madera y la función de los tijerales de sostenimiento en la prevención de la comba del techo.

May 1, 1981

By Mario Samamé Boggio

El presente texto señala los progresos recientes respecto de la siderurgia y la ferrominería en algunos países de América Latina. En el caso de Argentina, la vanguardia tecnológica radica en el aumento de la capacidad productiva y la tendencia hacia una aminoración en la tasa de crecimiento del consumo interno, crecimiento de la producción, exportaciones y en los problemas de abastecimiento interno y externo de chatarra y semiproductos. En el caso de Brasil, el sector de aceros tiene relevancia con la inauguración de la plan a de la empresa Acos Finos Piratini, en Río Grande do Sul. Esta cuenta con instalaciones de reducción directa, donde se utiliza carbones pobres de la misma zona y con capacidad para 65.000 t por año de fierro esponja. La industria siderúrgica de Colombia mostró en J 972 nuevos avances en sus cifras globales de producción de acero y en sus niveles de productividad. En Chile, la Compañía de Acero del Pacífico se dispone a construir una planta de peletización, que utilizará finos provenientes de sus minas de Algarrobo y Boquerón Chañar. En Ecuador, la empresa ANDEC, que está operando a un nivel de 30,000 t. anuales de laminados, definirá su programa para encarar la producción de barras en rollos y alambrón. Finalmente Perú, definió su programa de desarrollo siderúrgico, el cual contiene inversiones que para 1990 sumarán unos mil millones de dólares.

Mar 1, 1975

By William J. Bryson

Just picture, if you will, the hot, lonely and desolate Ochre Mountains west of Salt Lake City. There works a grizzled old miner, his boots worn down, his clothes hang on a body stooped by years of hard labor. His skin is wrinkled and leather toughened by many years in the hot desert sun. His ever faithful burro stands patiently in the shade of a large rock as the tired old miner examines ore samples just acquired that very morning. Suddenly the old man&apos;s eyes widen, his breathing becomes rapid. &apos;Leaping to his feet, with a gleam in his eye, he cries, "Eureka, I&apos;m rich, I&apos;ve found the mother lode. This is where I will start my digging. " Without warning, the silent wilderness is alive with wild, shouting, charging figures! Frightened the old miner glances about him wide-eyed and pan- icky. His heart sinks, dismayed he now knows all is lost, this is the end. For there leaping from behind rocks and brush papers in hand, are the men from the Department of Interior, Bureau of Land Management, State Mine Inspectors, OSHA, MESA, EPA, OEO, and the never ending list of regulatory bodies related to todays mining industry.

Jan 1, 1975

By J. R. Finlay

THE other day, I fell into conversation with two gentlemen who desired to improve the condition of the people; so that the talk was semi-political. They seemed to agree that I was inclined to be "con-servative," "reactionary," perhaps an "evolutionist," looking upon "reform" with suspicion. Finally I rejoined somewhat in this manner: "You attach to me phrases that I have heard all my life but which convey no meaning to me. It is quite true that I do not make a fetish of terms like reform, liberty, democracy and so forth; neither do I worship the idea that `things are good enough as they are,&apos; `leave well enough. alone&apos; and so forth. There is more satisfaction in building something up than in tearing something down, or in just maintaining something that is already built. Progress is a popular word; but what is progress? In my opinion it is comprised, so far as public welfare is concerned, of two elements: Improvements in production of goods and knowledge; improvements in keeping order." This substitute for politics, economics, reform, pro-gress, conservatism, radicalism, democracy, socialism, monarchism and all the phrases of public welfare may seem over-simple; perhaps it is, but at least it defines something. It seems to me to be at least worth attention.

Jan 4, 1922

By Takahide Wakamatsu, Junji Shibata

Complex polymetallic sulfide ore deposits occur in Tohoku district, northern part of Honshu island, Japan. The ore is locally called "Kuroko” ( black ore ) and is compactly composed of fine grained sulfide minerals of such principal metals as copper, lead, zinc and iron. Currently one of Kuroko mill plants is producing such concentrates as copper, lead, zinc, pyrite, barite, and clay minerals, mainly employing differential flotation techniques. This paper describes briefly the progress of techniques in Kuroko processing over the past thirty years and also the present state of Kuroko processing and its challenges to be studied and overcome in the future.

Jan 1, 1989

By G. H. Gronhovd

The U.S. Geological Survey estimate of the total remaining reserves of lignite in this country as of Jan. 1, 1967 was about 448 billion tons. This represents 27 percent of the total coal reserves on a tonnage basis and about 17 percent on a thermal basis. Approximately 98 percent of these reserves are in a vast lignite field located in western North Dakota and eastern Montana. This field also extends north into the Canadian province of Saskatchewan. Despite these large reserves and relative ease of mining by stripping operations, lignite production historically has accounted for less than 1 percent of the national total. This is largely due to the fact that the lignite deposits are located in an area that has no large centers of population and the economical radius of transportation is limited by its relatively high moisture and low heating value. Commercial utilization of North Dakota lignite for power production became firmly established in the mid-1920&apos;s with the development of the first successful lignite-burning equipment. Most of the early lignite-fired boilers were equipped with spreader stokers, but as the size of the plants increased, pulverized-coal firing became the more popular method, and with few exceptions, the plants built during the past 15 years are pc-fired.

Jan 1, 1968