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By Luis Mejía, Elizabeth Meza, Melissa León

Dentro de la Política Ambiental de la empresa se tiene el compromiso en la Gestión Sostenible del agua, donde se busca maximizar la eficiencia operativa en las unidades respecto al uso responsable del agua en cantidad y calidad; a través de prácticas de recirculación y reúso del agua y la prevención de impactos negativos al ambiente, aplicando controles y monitoreo de la infraestructura hidráulica y el tratamiento de efluentes; en cumplimiento de los instrumentos ambientales aprobados y de la legislación ambiental vigente.

Sep 29, 2023

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 Donald L. Bott

A computer model called the Quality Compliance Model was developed to optimize the mine planning and sequencing in area coal mining with respect to the limit on pounds of sulfur dioxide per million BTU imposed by regulations. The objective of the model is to maximize the amount of high sulfur coal mined from various benches while meeting the specified compl'ance standards. Given multiple seams and multiple benching operations, the mining sequence from each pit is simulated. The rate of mining is controlled such that the in-pit blending will maximize the usage of high sulfur coal and meet compliance standards. The compliant coal can be stockpiled for usage at a later date, or it can be disassociated. This calculation can be based on any given rate of production, i.e., from as small a unit as a unit train to as large as monthly or yearly production.

Jan 1, 1982

By W Whiten

The determination of mineral composition is necessary in the mineral sands industry. Tiwest has developed a procedure for safe and convenient determination of the mineral composition using a magnetic separation followed by chemical analysis using X-ray fluorescence spectroscopy. This then requires the conversion of the elemental assays to mineral compositions. A project at the Julius Kruttschnitt Mineral Research Centre has developed a convenient analysis method for this conversion. This analysis is based on a reconciliation of the of the assays of the sample with the standard mineral assays by making minimal adjustments based on the assay accuracies to both sets of assays. As well as providing the mineral composition it to be tested for other applications and variations of the procedure to be evaluated. Given a range of samples, testing for the accuracy of the assays of the standard minerals, has been demonstrated.

Jan 1, 2001

By Chris Joyce, Peter Ryan, Graeme Mcllveen

This paper briefly summarizes regulatory procedures and government agency roles and jurisdictions in each Australian State and Territory. The role of the Commonwealth of Australia and selected current trends in environmental regulation are also discussed. While the Commonwealth has played an active role in regulating specific commodities or mines through its powers over export licences, international heritage agreements and the Territories, such cases have largely been a result of response to specific public issues. This may change; the Commonwealth has established the Resources Assessment Commission and is canvassing the establishment of an Environmental Protection Act, aimed at the standardization of environmental standards through the creation of an Environmental Protection Authority. While the States, the Northern Territory and the Commonwealth lwve nominally different resource planning, environmental project approval and operational regulatory authoritit:s, the fundamental principles hinge on mining lease, planning and pollution control approvals.

Jan 1, 1991

By O. C. Ralston, L. H. Duschak, R. D. Pike

Much detailed information on the production of plastic magnesia from magnesite mined near Chewelah, Wash., was accumulated during a cooperative investigation conducted by the Bureau of Mines and the Northwest Magnesite Co. at the laboratories of the University of California in 1919-1921. This bulletin gives mainly the results of the work done with Chewelah magnesite, supplemented by data on similar work with other magnesites, particularly those of California, in the endeavor to produce a plastic magnesia that would be satisfactory for making the so-called " Sorel" cement composition flooring, stucco, and plasters. As standardized methods £or testing such compositions did not exist, it was necessary to examine carefully the various methods in use and choose those that seemed appropriate. In consequence, this report contains many tests made by the methods selected and can be used £or reference by those who wish to adopt standard methods of testing.

Jan 1, 1925

By Jorge Amaya

A critical aspect of long-term open-pit mine planning consists in computing a production schedule based upon a block sequencing strategy. Such a schedule should specify when and if blocks should be extracted in such a way as to maximize NPV, while satisfying wall-slope and production capacity constraints. It is well known that this problem can be modeled with integer programming (IP). However, integer programming is not used in practice because the size of typical block models makes such problems intractable to standard IP solvers. In this article we describe a scalable IP-based methodology for solving very large (millions of blocks) instances of this problem. We show that embedding standard IP technologies in a local-search based algorithm we are able to obtain near-optimal solutions to large problems in reasonable time. This methodology has been tested in several mine wide block models.

Oct 1, 2009

At the annual meeting of the American Society of Mechanical Engineers, Dec. 4 to 7, 1917, a great many matters were discussed and acted upon in which nearly all engineers are equally interested. Of the numerous sessions of the meeting, only a few of the most important can be referred too here. The Committee on Gages held an open meeting for the discussion of this important matter. Representatives from a large number of manufacturing plants and from several departments of the Federal Government were present. The question of gages and standardization of mechanical details is of course of paramount interest just now in connection with the manufacture of ordnance and ammunition. After discussion, the following recommendation was adopted by the meeting, for inclusion in all Government contracts for the manufacture of these materials. The maste and reference gages and standards of measurements, with which Ore

Jan 1, 1918

By Jorge Amaya

A critical aspect of long-term open-pit mine planning consists in computing a production schedule based upon a block sequencing strategy. Such a schedule should specify when and if blocks should be extracted in such a way as to maximize NPV, while satisfying wall-slope and production capacity constraints. It is well known that this problem can be modeled with integer programming (IP). However, integer programming is not used in practice because the size of typical block models makes such problems intractable to standard IP solvers. In this article we describe a scalable IP-based methodology for solving very large (millions of blocks) instances of this problem. We show that embedding standard IP technologies in a local-search based algorithm we are able to obtain near-optimal solutions to large problems in reasonable time. This methodology has been tested in several mine wide block models.

Oct 1, 2009

By Gilbert P. Moore

Production in the Argentine in 1930 amounted to 1,415,099.7 metric tons, which converted into barrels of 42 gal., using the factor of 6.29, amounts to 8,909,773 bbl. This is a decrease of 481,613 bbl. from the 1929 production, which was 9,391,386 bbl. The production for 1930 was divided among three fields, as shown in Table 1. Table 2 covers Table 1.—Argentine Oil Production, 1930, by Fields Barrels Comodoro Rivadauia District Government........................................... 4,547,670 Railways Co........................................... 1,314,358 Astra-Eastern......................................... 1,016,024 Anglo-Persian......................................... 365,021 Solano Co............................................. 24,613 Dutch Shell........................................... 6,963 7,274,649 Neuquen District Government........................................... 569,245 Standard Oil-Argentina................................. 659,551 Astra-Eastern......................................... 8,234 Challaco Co. (Sol)...................................... 121,598 1,358,628 Salta District Government........................................... 90,576 Standard Oil-Argentina.................................. 185,920 276,496 8,909,773

Jan 1, 1931

By Li Keqiang

Among the pile foundations of the 156 tall buildings over 18 storeys in Shenzhen, 86. 5% of them are constructed by slurry drilled piles, bored piles and excavated piles (hand-dug caissons). Based on the experiences of the engineering practices, the paper points out that the main quality problems of pile foundations in Shenzhen are: insufficient bearing capacity of single pile; poor concrete quality of pile; damage of the precast pile; pile tip not reaching the required bearing stratum and the thickness of bored/drilled sediment exceeding the specified. etc. The quality inspection methods that have been used include: check of construction records and excavating; static loading test; core sampling test; non-destructive test, etc. Treatments of quality problems used in Shenzhen are also introduced in this paper.

Jan 1, 1991

By Waldemar Lindgren

CONTENTS. [ ] I. INTRODUCTION. THE precious metals, gold and silver, are the basis of the monetary systems of the world. It is, therefore, natural and inevitable that widespread interest should be manifested in their production and in the various classes of deposits in which they are contained. At times a great scarcity of the precious metals has prevailed; at other times the production has seemed so abnormally large that fears have been entertained regarding their ultimate retention as standards of value. Since most nations have adopted the gold standard, and the remaining ones appear likely to do the same in the near future, the question of available supply of gold for the present and future very naturally arises. This necessarily involves a consideration of the characteristics of the gold-deposits. After the absorption of the gold treasures of the New World by the conquistadores, the gold-placers of Brazil and Russia

Jan 1, 1913

In comparisons of a trial extruded brick containing 33 per cent coalwash and 67 per cent clay and a trial pressed brick containing 100 per cent coalwash with a standard extruded clay face brick, the mixed feed stock trial brick compared favourably with the standard brick. If a highly plastic clay is used to mix with the coalwash, satisfactory results are obtained in respect to dimension, strength, water absorption, efflorescence, resistance to salt attack, hardness, colour, weathering, mineralogy and porosity. Although a brick containing only coalwash can be successfully manufactured in a press, its mechanical and physical properties are inferior. This mixed feed stock brickmaking technology leads to the utilisation of a by-product with a potential saving of raw material costs. The extent of use is likely to depend on the proximity of the coal washery and the brickworks and the economicsof transportation costs.

Jan 1, 1992

By R. L. Blake

The crystal structure of hematite, a-Fe203, has been refined as part of a continuing study of the behavior of phases in the Fe-O system during reduction and oxidation. Three-dimensional diffraction intensities were collected on two spherical single crystals of hematite with a semiautomated Buerger single-crystal diffractometer. The first crystal refined was a natural Elba hematite with minor impurities. The other, a synthetic crystal, was refined at the request of Mossbauer spectroscopy investigators concerned with impurities in the natural crystal. The structure has been refined with a least-squares program and the final structure for the natural crystal irradiated with CuKa-radiation gave a discrepancy factor (R) of 3.65 percent using 49 unrejected reflections of the 51 measured. For the synthetic crystal, using MoKa-radiation, the discrepancy factor converged to 2.8 percent using 95 unrejected reflections and was 3.3 percent for all 109 reflections. The structure model of Pauling and Hendricks has been confirmed with essentially no change in the iron coordinates and approximately a 5-percent change in the oxygen coordinates. Selected interatomic distances and angles were calculated as were anisotropic temperature factors.

Jan 1, 1970

By Shiels O. J

The major Permian coal deposits of N.S.W. are in the Sydney-Bowen Basin and associated small deposits occur in structurally isolated areas; a further deposit is present in the Oaklands Basin. - The Sydney-Bowen Basin in New South Wales comprises the sub basins, the Sydney Basin and the Gunnedah Basin. Coal measures in these basins are near the top of the Permian succession and within and below an underlying marine sequence. The coal deposits can be conveniently described in units in which the coal geology is homogeneous. The Clyde Coal Measures and Yarrunga Coal Measures contain no seams of economic significance and occur beneath the marine beds in the south of the Sydney Basin. The Greta Coal Measures are economically significant and represent a brief interlude in the marine sequence in the north of the Sydney Basin and equivalents are present in the east of the Gunnedah Basin. The Tomago Coal Measures crop out above the marine sequence east from the Lochinvar Anticline and dip southeast to uneconomic depths. The Newcastle Coal Measures are historically and economically very important and overlie the Tomago Coal Measures and these measures will continue to be important although future mining will be faced with greater depths. To the west of the Lochinvar Anticline the Singleton Coal Measures, equivalent to the Tomago and Newcastle Coal Measures, crop out. This unit represents the thickest development of coal measures in the State and has a very large potential for both open cut and underground mining. Equivalents of the Singleton Coal Measures, the Black Jack Coal Measures and the Booroomin Group crop out on the east side of the Gunnedah Basin and probably are widespread across the Basin. They have less economic potential than the Singleton Coal Measures. In the southwest of the Gunnedah Basin, Illawarra/Singleton Coal Measures crop out over extensive areas and possibly have a large potential for underground mining under low cover. The Illawarra Coal Measures are exposed along the western margin of the Sydney Basin and thicken as they dip into the Basin across a shelf. The outcrop area is currently mined and the shelf has considerable potential for future mining. The highest rank coals in the State are in the Illawarra Coal Measures in the south of the Sydney Basin. The deepest coal mining is in this area and its continuing success is of great importance to the future exploitation of the resources of the Basin. The Tomago, Newcastle, Singleton and Illawarra Coal Measures extend into and meet in the central area of the Sydney Basin but they are under thick cover and are not considered to be economic at present. Permian coal measures occur in isolated areas in the New England Fold Belt and have limited economic potential. The Oaklands Basin in the south of the State contains a large reserve of low rank coal.

Jan 1, 1975

By Les Johnston

_ BACKGROUND - About EPCOR - Genesee Generating Station - Phase 3 Expansion _ TECHNOLOGY SELECTION - Selection Criteria - Combustion Options - Flue Gas Emission Control Options _ STAKEHOLDER VIEWS _ PROJECT STATUS _ EPCOR is an integrated utility company for water, gas, electricity and technology services. _ EPCOR has about 1.6 million customers in Alberta, Ontario, Manitoba, BC, and the U.S. Pacific Northwest. _ EPCOR Generation Inc. operates three power stations in Alberta which were in operation before deregulation, including the coal-fired Genesee Generating Station. _ EPCOR Power Development Corporation owns generating stations in Alberta, BC and Washington State and will be building the Genesee Phase 3 expansion.

May 1, 2002

By Ronald Ticona, Marjorie Aubert, Frank Luján

Uno de los principales objetivos en la optimización de los procesos mina a planta es la obtención de una buena fragmentación en la voladura, el cual permitirá generar la cantidad de finos adecuados para la alimentación de la planta concentradora. Con la finalidad de evaluar los efectos de la fragmentación en mina en los procesos aguas abajo desde la voladura, una importante mina de cobre del Perú decidió evaluar el impacto en los procesos aguas abajo de dos tipos de explosivos, de emulsión 100% gasificable con RBS de 118 y de mezcla explosiva gasificada 80/20 con un RBS de 158, en zonas de roca altamente competente con un rango 150 a 160 de UCS y 0.8 de RQD.

Sep 29, 2023

By R. V. Ramani

This report is volume 3 of an eleven-volume final report for a Grant completed by The Pennsylvania State University for the Bureau of Mines to develop a dynamic general purpose computer simulation model for underground coal mining. The simulator developed under the Grant has a wide range of possible applications in the design and evaluation of underground coal mining systems from the standpoints of health and safety, productivity, and mine environment. The Master Design Simulator consists of nine free-standing function-oriented subsystem models linked together into an integrated, comprehensive model of an entire mining system. The subsystems comprising the Master Design Simulator include geology and reserves, methane generation, roof support, subsidence, production, rail haulage, cost, water generation,' and ventilation. This volume of the final report describes the Methane Generator subsystem of the Master Design Simulator. This subsystem is used to determine methane emission rates into the mine environment. These flow rates are then used by the simulator in planning primary and secondary ventilation systems, planning a methane drainage system, and analyzing complex ventilation networks. Both steady state and unsteady state gas flows are included, and have been modeled as second order nonlinear partial differential equations. Finite difference equations are used to obtain numerical solutions to the models using a central differencing scheme. An application of the model is presented. The appendices include derivation of the gas flow equations used in the model as well as a users manual for the computer program.

Jan 1, 1974

By Sam Bang Jr, Rodney Burke

As mining progresses in the West, the depth of material has increased, making highwall stability a major factor in safety and production. The Jim Bridger Coal Mine’has made highwall stability a priority, concentrating on safety as well as increasing and improving production. Overburden depths are increasing dramatically; the geological environment consists of medium to sot? material, faulting, water, and current pit alignment not favorable to joint planes. Angle drilling the presplit at 20 degrees became necessaryas vertical presplit drilling produced wall failures.

Jan 1, 1998

By Allan Sylvester

Construction of the Shot Tower Metro Station in Baltimore, Maryland was performed in two phases. In the first phase, a contractor was retained to excavate the station in order to construct twin tunnels from the Shot Tower Station to the John Hopkins Station. The retention system for this 70' deep excavation consisted of a Soldier Pile in Tremie Concrete (SPTC) wall supported by cross-lot bracing. In phase two, The Clark Construction Group, Inc. was retained to construct the station interior structure, two entrances, two station ancillary shaft structures and the track work for the station and tunnel. The excavation for the construction of the two entrances adjacent to the 70' deep station SPTC wall had to proceed prior to completion of the station structure due to the tight construction schedule. A system of overlapping secant piles was specified as a vertical support of excavation element for the West Entrance. The secant piles would have provided a watertight, rigid support to resist the load from the SPTC wall constructed in phase one. A watertight system was required in order to minimize the settlement of adjacent buildings supported on wood piles. Clark Construction was concerned with the constructability, cost and performance of the specified secant piles and looked for other innovative methods of providing a watertight and rigid system. Substitution of a reinforced slurry wall in lieu of the secant piles was cost prohibitive due to the additional cost of concrete placed under tremie. Clark, being familiar with cement-bentonite cut-off walls and slurry wall construction procedures, proposed the construction of a PSHG wall, in lieu of the secant piles. The PSHG wall construction consisted of trenching 30" wide by 20' long by 60' deep panels under a self-hardening slurry. Once the excavation for a panel was completed, a 60' deep prefabricated soldier beam and lagging panel was placed in the slurry. The slurry design mix then self-hardened within the cure time, allowing excavation for the structure to proceed This paper will discuss the design, details and construction methods used on the PSHG wall and will compare the advantages of the PSHG system to conventional support systems.

Jan 1, 1997