Search Documents

By K. J. Bathe

The current version of the computer program ADINA/BM (Automatic Dynamic Incremental Nonlinear Analysis for the Bureau of Mines) for linear and nonlinear, static and dynamic finite element analysis of mine structures is described. The complete report is divided into four parts. In Part A the program solution capabilities, the finite element library, the logical construction of the program and storage allocations are discussed. In Part B the theory and numerical techniques used in the program are summarized. In Part C brief problem descriptions and solution results for some sample solutions that have been transmitted as data cases with the program are presented. In the last section of the report, Part D, the users? manual of the program is presented. Program ADINA/BM is a general effective tool for coal mine structural analysis. The program is an extension of the computer program NON SAP (which was developed under an earlier contract with the U.S. Bureau of Mines). The important additional capabilities of ADINA/BM are: (1) the occurrence of all elements is time dependent, (2) all elements can be used in geometric and material nonlinear analysis, (3) the truss element can be used in elastic-plastic analysis, (4) the three-dimensional element can be employed in orthotropic, elastic-plastic and cracking and crushing analysis, (5) the program executes an out-of-core solution and thus allows the analysis of very large and complex coal mine models, (6) the truss elements can be employed as 2-4 variable-number-nodes elements, (7) a rock material model has been implemented, (8) displacement constraint equations can be imposed in the solution, (9) more flexibility in specifying the incremental solution strategy and an acceleration procedure in the equilibrium iteration are available

Jan 1, 1978

By J. C. Martin

Stmplified equations are developed for the flow of fluids in gas drive reservoirs in which the effects of gravity can be neglected. The results show that the pressure distribution is governed by a nonlinear heat flow type of equation, and the saturation distributions are related to the pressure by the same equations QS those developed by Muskat for the average pressure and saturations in gas drive reservoirs. Unrler certain conditions the equation for the pressure can be approximated by the linear form of the heat flow equatlon. This equation tk analogous to the equation for the pressure in single-phase compressible flow The analysis reveals that the equation for the pressure in n~ultiphase flows can be obtained directly from the equation for the pressure in slngle-phase flows by simply replacing the single-phase compressibility by the total compressibility and the single-phase mobility by the sum of the mobilities of all the fluids present. Perrine's method of pressure buildup analysis for multiphme flows is based on these same substitutions. Thus, the development presented in this paper constitutes a theoretical justification for Perrine's method of pressure buildup analysis. One of the most difficult problems associated with the production of oil is the determination of the flow of the fluids within the reservoirs. One purpose of this paper is to present the development of simplified equations for the flow in gas drive reservoirs. The other purpose is to present some of the needed theoretical foundation for the methods currently being used in the analysis of multiphase pressure buildup data. The analysis presented in this paper makes use of a partial linearization of the equations governing multiphase flows. It is felt that the process of linearizing or partially linearizing the nonlinear equations of multiphase flows can lead to useful results since this process has proved extremely valuable in the study of other fields of science and engineering where nonlinear equations are encountered. Pressure buildup data of shut-in wells have been used for many years to estimate the static reservoir pressure. These data have also been used in studying the aver- age permeability both away from and close to the well-bores. The majority of the buildup data are obtained from wells producing two or three fluids. As yet the theoretical foundations for the methods of buildup analysis used in connection with rnultiphase buildup data have not been established. A number of methods of analysis of pressure buildup data have been developed." Most of these methods apply only to single-phase flows, and almost all of the theoretical analysis is confined to single-phase flows. Perrine' developed a method of analysis for rnultiphase flows from the method for single-phase flows of Miller, Dyes, and Hutchinson.' He did this by simply replacing the single-phase compressibility by the multiphase compressibility and replacing the single-phase mobility by the sum of the mobilities of the fluids in the rnultiphase flows. Obviously, such a procedure lacks a certain amount of theoretical justification, and such practices can lead to erroneous results. Fortunately, Perrine's results have a theoretical justification, and this justification is presented in the following discussion. It is assumed that gravitational effects and the cornpressibility of the rock can be neglected. Under these assumptions the equations governing the simultaneous flow of gas, oil and water in porous media areo* The preceding equations can be expanded into the following expressions.

By Bjørn Nilsen, Werner Stefanussen

The construction of the Guaigui Multipurpose Project includes a 74 metre high concrete face rock fill dam, a 350 metre long diversion tunnel and a 350 metre long spillway tunnel. The topography in the project area is very steep, and the rock masses are characterized as soft rocks. The stability of the 80 to 100 metre high dam abutments and the excavation of the tunnels in soft rock conditions have caused various challenges and problems to be solved. Limited pre-investigations have called to a great extent for estimation of parameters for the stability calculations based on experience. The preliminary calculation of the stability of the planned rock slope above the spillway intake platform has been carried out by conventional partial factor methods and by use of a computed based Slide Program. The two methods of calculation give different results , and that rock support is necessary to obtain an acceptable factor of safety for a slope inclination of 52o. The input parameters for the rock mass characteristics need to be verified for the permanent calculations.

Jan 1, 2006

By Donald J. Barnes

There are no producing or developing mines in the study area. The only mineral production was stone from a basalt deposit near Indian View Point. Cinders and sand and gravel have been produced from deposits within 1/2 mi (0.8 km) of the boundary. Stone, sand and gravel, and cinder deposits inside the area are not considered resources because equal or better quality material is found closer to markets. The study area has no known oil and gas, coal, geothermal, or other energy related deposits. However, in 1982 application was filed on 25,000 acres (10,125 ha) of petroleum and on 15,000 acres; (6,0/5 ha) of geothermal leases.

Jan 1, 1983

Improving the Sustainability of Primary Metal Production - The Need for a Life Cycle Approach

Sep 13, 2010

By Guillermo Manrique

El presente texto describe las estrategias planteadas por la empresa Southern para la convivencia pacífica con las comunidades afectadas por el desarrollo de las operaciones mineras. Para ello, se requiere definir los objetivos y la filosofía corporativa (responsabilidad social) que garantice el apoyo de dichas propuestas. Asi también se realiza un estudio base de la comunidad, donde se priorizen las necesidades de las comunidades a través de la estrategia de concertación y así ejecutar proyectos participativos de desarrollo social. Finalmente, la información recolectada se sustenta y validad por las experiencias llevadas a cabo en las 36 comunidades del entorno de las operaciones de SPCC, convirtiéndose en un aporte para el tratamiento comunitario.

Sep 13, 2001

Effects of High Pressure Grinding Rolls on Platinum-Bearing Ores and the Flotation Response as Compared to the Conventional Ball Mill Three major PGM ore types from the Bushveld Complex of South Africa: Merensky, UG2 and Platreef were comminuted with the use of the high pressure grinding rolls (HPGR). The influence of the feed characteristics and the various operational and design features of the HPGR on energy consumption, throughput, mineral liberation and PGM flotation recovery were investigated. The test work variables included two feed top sizes of 12 mm and 6 mm, specific grinding forces ranging between 3 - 7.5N/ mm2 and zero gaps of 1.5 mm and 3 mm. The results show that the influence of the HPGR operational and design features on energy consumption, throughput, mineral liberation and PGM recovery are ore dependent. The size reduction-specific energy relationships show that the most energy efficient utilisation of the HPGR for Platreef ore was at the lower specific grinding force of 3N/mm2 and the zero gap at 3 mm. For Merensky and UG2 ore on the other hand, the most energy efficient operation was at the higher specific grinding force of 7.5N/mm2 and the zero gap of 1.5 mm. At a specific energy input of 3 kWh/t, reduction ratios (F50/P50) of 6.5, 3.8 and 10 were obtained for Merensky, UG2 and Platreef, respectively for feed top sizes of 12mm. Further application of the HPGR as a pregrinding stage to a ball mill showed a 25 - 30 per cent increase in throughput for Merensky and UG2 ore. Batch flotation tests performed on selected samples appear to indicate that ore comminuted with the ball mill had superior grades compared with that ground with the HPGR. However, Merensky and UG2 ore comminuted at different HPGR operating conditions showed distinctions in PGM recovery. Platreef on the other hand did not appear to show any differences. Therefore, this study highlights the significance of ore type and operating variables in HPGR applications with regards to energy efficiency, throughput and PGM recovery.

Sep 13, 2010

The first annual student prizegiving function of the South African Institute of Mining and Metallurgy was held in the Dorothy Susskind Auditorium, University of the Witwatersrand, on Thursday, 26th May, 1977. The address (see opposite page) was given by Dr M. G. Atmore, a director of Anglo American Corporation and Vice-President of the Institute.

Jan 1, 1977

By T. McKeon

Gravity separators are commonly used in multistage cleaning and scavenging circuits to improve the quality and/or recovery of the final concentrate. Unfortunately, studies suggest that many industrial plants are poorly designed in terms of equipment layout. This shortcoming can often be attributed to a failure by engineers to make use of fundamental process engineering tools for circuit design. One of the most important of these is linear circuit analysis. This powerful tool makes it possible to mathematically compare the relative efficiencies of circuit configurations in advance of experimental testing. This article provides a basic review of the linear circuit analysis concept and discusses some of the key insights it provides for the layout of multistage circuits. An industrial case study is provided to show the tremendous impact that this process engineering tool can have on the design of multistage spiral circuits in a heavy mineral wet plant.

Jan 1, 2005

By Ulrich Paschedag

The WESTFALIA group of companies developer and manufactures underground mining machinery for complete high-performance longwalls. WESTFALIA uses a state of the art electrohydraulic system as the most important component for the realisation of today's fully automated plow or shearer longwall. The shield control unit (SCU) allows maximum custom designed software flexiblity as well as maximum hardware reliability. The master control unit (MCU) monitors shield support data as well as the plow/shearer position. By using an industry standard PC in an explosion-proof box with an intransically safe keyboard nearly unlimited software capabilities can be obtained with inexpensive hardware. Among various other modes of operation this MCU allows the monitoring and recording of data which can be transmitted to a surface computer. Production and operational adjustments can be made by the mine management based on the MCU information. Statistical analysis of the distribution of roof pressure under various conditions is also possible. The WESTFALIA automation system PM-4 gives the operator maximum flexibility and helps the mine management to run their longwall more efficiently and safely.

Jan 1, 1994

By Michael P. Sudbury

Non-ferrous slags are granulated and stockpiled as an alternative to pit cooling or transporting molten slag to a dump. The chemical composition of such slag is determined by the pyrometallurgical process in which it is produced, while the size distribution is set by safety concerns or a desire to reduce wear of pumps, pipelines and other equipment. Relatively few operations give consideration to the effect of granulation conditions on other properties of the granulate as the material is typically accumulated on the smelter site. It is becoming recognized that slag has many potential commercial uses and carries much of the energy applied to the smelting operation. This paper outlines the findings of extensive work to identify uses for granulated non-ferrous slag, the importance of preparation conditions on the properties, impediments to more extensive use of granulated slag, the real costs of slag stockpiling and the opportunities for further productive research.

Jan 1, 2006

By Ted J. Williams

Underhand cut and fill mining methods are used at the Lucky Friday, Stillwater, and Galena mines in the western US in an effort to safely mine in difficult ground conditions and as a primary mining method where access below the ore is limited. The method has evolved at each mine to meet the unique situations associated with their milling procedure and mine layout. Details of the operational aspects of the backfilling and mining cycles at each mine are presented in this paper, accompanied by a summary of the mechanical properties of the backfill and its in-situ geomechanical behavior.

May 1, 2007

In June, 1,334 underground construction and tunneling professionals gathered in Toronto, Ontario for the 2007 Rapid Excavation and Tunneling Conference (RETC). This biennial event, sponsored by SME, is one of the global underground construction industry?s major events. And this year?s RETC was the first one that included the new Underground Construction Association. [ ] (UCA) of SME. In addition, the conference?s exhibit attracted 125 equipment and service providers. The next Rapid Excavation and Tunneling Conference is set for June 14-17, 2009 at Caesar?s Palace, Las Vegas, NV.

Jan 1, 2007

By Serge Moalli

The Ashlu Creek Hydro-electric project, located north of Squamish, BC, at the confluence of Ashlu Creek and the Squamish River, comprises a 49 MW run-of-river project and features a 4.08 m diameter, 4.4 km power tunnel and a 128 m deep drop shaft. The Ashlu Creek Hydro-electric project is being developed by Innergex under Ashlu Creek Investments Limited. Site civil works are being completed by Ledcor CMI of Vancouver with tunnel construction by Frontier Kemper Constructors ULC under a lump sum design-build contract. Site works got underway in September 2006 with the construction of the tunnel portal and laydown area. These site works required rock slope stabilization over a 50 m rock slope to secure the laydown area as well as the construction of a tail track muck tipping station and structural wall to facilitate TBM excavation and spoil removal. Starter tunnel construction commenced in early 2007 and TBM tunneling started in the late spring of 2007 and is planned to continue until early 2009. The power tunnel is being excavated using a 1,200 kW Wirth open-type hard rock TBM dressed with 31?17' cutters. The TBM featured two fixed mounted rock bolt drills behind the finger shield: these were removed and replaced with jacklegs to improve access. A probe drill at the end of the main beam is also present. The geology along the 4.4 km power tunnel comprises very strong and generally massive granitic bedrock with rock strength greater than 225 MPa. A unique feature of the project is that no subsurface investigations have been completed for the tunnel however extensive bedrock outcrops are present along the Ashlu Creek valley. A historical quarry exists approximately mid-way along the tunnel alignment that has exposed good quality granitic bedrock. TBM tunneling to date has achieved advance rates of 10?20 m/day with a maximum of 23 m and has encountered all of the anticipated six major fault zones where the installation of various standard high capacity tunnel support was successful to facilitate TBM advance through these sections.

By Vilma Beltrán

Dado que los trabajos de procesamiento metalúrgico de la mina Uchucchahua, ocasionaron impactos en el medio ambiente, afectando la calidad del agua y eliminando la vida acuática en las lagunas Añilcocha, Colquicocha y Tinquicocha, se procedió a encontrar una alternativa de tratamiento biológico que recupere la calidad de vida en la mina Uchucchacua. En este sentido, el presente trabajo describe el tratamiento pasivo de los efluentes con manganeso de la mina Uchucchacua. Para dicho procedimiento, se desarrollaron trabajos en dos etapas: el de laboratorio y balde. El primero comprende los sistemas de tratamiento pasivo anaeróbico y aeróbico.El aeróbico se inició sobre la base de los procesos de filtración y aireación a fin de determinar el grado de oxidación y precipitación del manganeso como óxido, mientras que el segundo se realizó en función a los resultados obtenidos en la etapa laboratorio y comprende los siguientes procesos: filtración, autooxidación, aireación, sedimentación. En consecuencia, los procesos anaeróbicos no favorecen la reducción de Mn II en los efluentes estudiados, mientras que los procesos aeróbicos permitieron la disminución del manganeso.

Sep 13, 2001

By Patrick J. Doig

In mid-1991, the design/build contractor set to work on the Pergau HEP in a remote corner of Malaysia, armed with only a slim volume of conceptual drawings. The next five years saw roads, power lines, buildings, dams, and over 30 kilometers of tunnel constructed, followed by two years of E&M installation and commissioning. Along the way, the project overcame geothermal groundwater, faults, land disputes, monsoon rains, marauding tigers, and those most fearsome of foes, politicians and the press. This paper is a testament to the ingenuity, commitment, and persistence of the construction industry professionals who brought this massive project to fruition.

Jan 1, 2001

By Peter B. Lilly

Thank you, Syd, for the kind introduction and for inviting me to give the Keynote Address at this very prestigious gathering of some of the finest intellect and talent in the domestic and international coal industry. CONSOL Energy has been a part of this conference for its entire 24-year existence. We have presented 27 papers over that time. CONSOL employees have also been members of the planning committee for the conference, and we have been pleased to support the event both financially and with many participants. So I am honored to be here with all of you this morning, especially during such a positive period for coal. You can just feel the enthusiasm in this room for our industry, and for this conference. I can tell you, there?s also a lot of enthusiasm and excitement in CONSOL Energy?s boardroom. And our enthusiasm is mirrored on Wall Street. But there remains an ironic twist to all of this attention. Even when times are good, the coal industry seems to go largely unnoticed by the mainstream. Outside of West Virginia and other coal-producing regions, the industry still seems to lack influence and support, at least here in America. As an example, last month, an ABC News crew visited our Blacksville 2 Mine, near here, to do a feature story on increased employment in the coal industry.

Jan 1, 2006

By V Cullinan, D Buchanan

The Brunswick plant is located in Costerfield, approximately 40km east of Bendigo in central Victoria. Crushing, grinding, gravity gold concentration and flotation methods are used to produce a saleable gold concentrate and an antimony-gold flotation concentrate. This paper discusses the improvements made within the processing plant which have resulted in a 99% increase in throughput over nameplate capacity of 6 250 average tonnes per month to 12 445 average tonnes per month and increases of 12% gold (from 2007 average of 78% to 2014 average of 90%) and 16% antimony recovery (from 2007 average of 79% to 2015 average of 95%). This combined effort has resulted in an increase of equivalent gold ounces (AuEq oz) produced from 2010-2014 of 15 872 to 82 574 – a 66 702 increase.AuEq oz= Au oz +Sb t × Sb (US$/t)Au (US$/oz)CITATION:Buchanan, D and Cullinan, V, 2015. Improvements in bi-metal production at the Brunswick Plant, Costerfield, in Proceedings MetPlant 2015, pp 267–272 (The Australasian Institute of Mining and Metallurgy: Melbourne).

Sep 7, 2015

By Gilberto Nunez, Ron Eastman, Hector Parra

The prediction of blasting outputs has proven to be a sound engineering tool to provide a guideline for design improvement. It has also been demonstrated to be extremely useful in critical situations when production can be compromised and there is no chance for error.

Jan 1, 2015

By C. Kasatuka

Globalization creates investment opportunities for enterprises around the world. Attracting foreign investment has been a key challenge for economic growth in developing countries. Corruption, political instability, armed conflict, and other internal problems affect foreign direct investment (FDI) inflows negatively. A framework of criteria provides a basis for comparing non-commercial risk (NCR) among twenty-three mineral economies. Countries competing for foreign direct investment inflows are ranked from least to most risky. This study compares Inward FDI Performance Index (IND) with NCR ratings in developing countries and shows that risk is increasingly mitigated by means of appropriately structured insurance. Given the option for countries with similar mineral potential, investors will generally invest in the country that offers lower non-commercial risk. Keywords: foreign direct investment, non-commercial risk, developing countries.

Jan 1, 2006