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By L. Yuan, A. C. Smith

To provide insights for the optimization of ventilation systems for U.S. underground coal mines facing both methane control and spontaneous combustion issues, a computational fluid dynamics (CFD) study was conducted to model the potential for spontaneous heating in longwall gob areas. A two longwall panel district using a bleeder ventilation system with a stationary longwall face was simulated. The permeability and porosity profiles for the longwall gob were generated from a geotechnical model and were used as inputs for the CFD modeling. In this study, the effect of methane emissions from the mined coal seam, including the longwall face and overlying rider seam reservoirs on the gob gas distribution was considered. The spontaneous heating is modeled as the low-temperature oxidation of coal in the gob using kinetic data obtained from previous laboratory-scale spontaneous-combustion studies. Unsteady state simulations were conducted, and the effects of the coal’s apparent activation energy and reaction surface area on the spontaneous heating process were also examined.1

By P D. Katsabanis

This chapter describes the principles for the derivation of the equations for a detonation wave. The importance of the equation of state for the detonation products is demonstrated and commonly used equations of state are discussed. Furthermore a brief introduction to the TIGER code is presented.

Jan 1, 1991

By Takashi Saito

Since early 1970?s skirt suction foundations (skirted foundation / bucket foundation) have been used as support for large fixed substructures or anchors for floating structures in offshore hydrocarbon development projects. In recent years skirt suction foundations are recognized as one of the solutions in foundations applicable to bridge substructures installed in waters, because skirt foundations have a wide variety of functions such as control of settlement during service life, less impact to environments during operation at installation site. This paper introduces general features of skirt suction foundations, and then discusses design practice of them for the application to bridge substructures, with reference to experiments in both laboratory and field.

Jan 1, 2013

By Alonso Marchena, William Martínez, Joel Otero

En Arequipa, Moquegua y Tacna se han definido diversos arcos magmáticos. En los arcos jurásico, paleoceno y oligo-mioceno ocurren pórfidos de distintas características, los cuales presentan diferencias litogeoquímicas (LaN/YbN>20, Sr/Y>40, Eu/Eu*>1, U/Th>0.27, NbN/TaN>0.7). Estos parámetros pueden ser utilizados como guías de exploración, ya que son anomalías desde el punto de vista litogeoquímico. En caso no haya mineralización visible (depósitos ocultos), el empleo de estos trazadores en unidades ígneas (diques, cuerpos subvolcánicos e intrusivos) puede señalar la probabilidad de encontrar depósitos en profundidad.

May 22, 2019

By Larry DeGraff

With the increase of new mine development in the past several years, many coal mines have decided to self- perform the design and construction for their slope development projects. The development process of determining the proper configuration is challenging, and a major economical consideration. Greenbrier Smokeless Minerals engineering staff and consultants, along with DSI/American Commercial, developed a support configuration that was best suited for their slope. The developmental process took into consideration the length of slope, depth of slope at the high-wall transition, economics of a single or multiple entries, waterproofing, stresses on the steel supports and lagging during the backfilling operation. This paper describes the developmental concept of using a single entry, side by side configuration, using steel ?Banjo String? supports with steel plank lagging, to develop a long term permanent installation in a cut and cover application.

Jan 1, 2009

By M. K. McCarter

The history of mining education, like the history of the mining industry, is typified by “boom and bust” cycles. In academia, the perpetual problem can be stated as “too many graduates for the jobs or too many jobs for the graduates.” The deep “bust cycle” that spanned the 1990s through 2003 spawned renewed efforts to eliminate, consolidate, restructure, rename, reinvent or otherwise change mining education to make it (for some) more fiscally or socially acceptable. During this period, a number of mining programs were eliminated, and by the late 1990s senior people in academia and their counter-parts in industry became increasing concerned about the very real possibility that strategic disciplines may disappear altogether. As a result, the Mining and Metallurgy Society of America (MMSA) created an educational committee to explore how industry could help preserve key programs necessary to provide future professionals. Several meetings were held to assess the problems and look for solutions. In 2004, this effort culminated in the first of the “Engineering Education” sessions to be held at the SME Annual Meetings. In response to the information presented in this first meeting, Marc LeVier (then president of MMSA) invited a number of the participants to reconvene the following day. An action plan was formulated and a task force was organized. To more fully represent all industry sectors, SME later that year assumed the sponsorship role for the task force.

Jan 1, 2007

A three?stages countercurrent fluidized bed prototipe reactor to neutralize the SO2from smelter gases has been developed. For gases with 8 vol-%SO2, at 800°C and for 4 h mean reaction time of the limestone, the capture of SO2 is 99%, with off gases with 0.07 vol-%. For 2 vol-%SO2, the total capture of SO2 can be obtained at 750°C and 4 h reaction time. The calcine obtained contain a blend of unreacted limestone and calcium sulphatewith minor amounts of residual lime.

Jan 1, 2006

By D. McBride

Representative samples are required from process streams in order to accurately measure chemical and physical characteristics. This information can then be used by process operators and metallurgists to evaluate the process and effect control actions for the operation. The capture and presentation of representative samples can be critical to measuring values, such as elemental analysis and particle size, with on-line or near-stream analyzers. A comprehensive multi-physics model has been developed and used to better understand the effects of slurry flow and particle segregation under certain operating parameters. An algebraic slip model coupled with a free surface algorithm is used to track motion and position of particles and phases within a specified geometry.

Jan 1, 2009

By Christian J. Sorensen, Christopher Armstrong, Andrew Matejunas

A team consisting of junior and senior mechanical engineering students at New Mexico Tech worked on the design of an explosively loaded vessel, with a maximum load of 15 grams (0.53 oz) TNT equivalent explosive. The main challenge presented was to meet the stringent sample positioning specification of 3 microns in two Degrees Of Freedom (DOF) and one degree of rotation in a third DOF. This is to accommodate precise sample placement in a tight x-ray beam, and to bring areas such as explosives/metal interfaces into magnified field-of-view photography. This presentation describes the process and design decisions to arrive at the final product presented to LANL in December 2014. Our engineering analysis techniques will be reviewed, including use of American Society of Mechanical Engineers (ASME) Boiling & Pressure Vessel Code (BPVC) Code Case for Impulse Loaded Pressure Vessels (ASME BPVC Code Case 2564-3). Also discussed will be integration of Hydrocode computer models with Finite Element Method analysis.

Jan 1, 2015

By James D. Noll, Eileen Birch

In a previous study, the e?cacy of commercial and prototype impactors for sampling diesel particulate matter (DPM) in coal mines was investigated. Laboratory and ?eld samples were collected on quartz-?ber ?lters and analyzed for organic and elemental carbon. Coal dust contributed a minimal amount of elemental carbon when commercial cascade impactors and prototype impactors, designed by the University of Minnesota (UMN) and the US Bureau of Mines (BOM), were used to collect submicrometer dust fractions. Other impactors were not as e?ective at excluding coal dust. The impactors evaluated in that study were either not commercially available or were multi-stage, expensive, and di?cult to use for personal measurements. A commercial version of the BOM impactor, called the DPM Cassette, was recently introduced by SKCs. Tests were conducted to evaluate the performance of the DPM Cassette for measuring diesel-source elemental carbon in the presence of coal dust. Bituminous coals from three mines in two di?erent coal provinces were examined. The dust particle diameters were small and the coal dust contained a high percentage of carbon, there by giving a worst-case condition for non-anthracite coal mines. Results for the DPM Cassette were essentially identical to those obtained by the BOM impactors in a previous study. At a respirable coal dust concentration of 5.46mg m3, which is 3.8 times the regulatory limit, the DPM Cassette collected only 34µg m3 of coal-source elemental carbon.

By B. M. Coombes

The McCracken and Stacey (1989) method of assessing geotechnical risk for largediameter raisebored shafts has been the basis for most Australian pre-construction raisebore investigations for the past 20 years. At the time of its publication, the McCracken and Stacey (M&S) Method did not include a database of raisebore diameter and rock mass conditions versus actual performance. It did, however, provide a chart that quantified geotechnical risk in terms of proposed shaft diameter and the raisebore rock quality index, QR. Two parameters, RQD/Jn and Jr/Ja were identified as being critical to raisebore stability, but the contribution of these to overall raisebore stability was not quantified. Peck and Lee (2008) published a database of raisebore performance from Australian case histories. Raisebore diameter and ground conditions, in terms of a Lower Bound QR value, were presented for 50 cases versus raisebore performance. This paper updates the database with further case histories and corrected SRF values. This paper further evaluates the reasons for the variable raisebore performance for similar RSR values. For all case histories, three parameters, RQD/Jn, Jr/Ja and Jw/SRF are investigated to assess their influence on raisebore performance.

May 1, 2011

By Arturo Ressi di Cervia

Construction of the drilled shafts for the Brightman Street Bridge Replacement Project were not only challenging due to working over the water but were also challenged by changed soil conditions, concurrent work being performed by an adjacent contractor on the same project, environmental restrictions and severe winter conditions. A total of 36 x 8 feet diameter drilled shafts with 7.5 feet rock sockets were installed for the East and West bascule piers. This project also included Osterberg Cell load testing on two production drilled shafts at each the East and West bascule piers. The results from the load test program were used to fine tune the design of the drilled shaft rock sockets. From a constructability standpoint the reverse circulation drilling method with a pile top drill rig proved to be an excellent choice for drilling the overburden and rock sockets of the large diameter deep drilled shafts.

Jan 1, 2003

By Son Hye Jin

Abstract ? KHNP is participating in the construction of Nuclear Power Plant both in Korea and UAE. ? We want to improve our construction project management process. ? So we are now developing the process model on nuclear power plant construction management. ? For the effective adoption of this process, we are planning to develop IT system. ? For the first step, we were established the Information Strategy Plan

Aug 1, 2013

Mining is an inherently risky business; from the technical, environmental, social, and economic uncertainties associated with advancing an exploration prospect to a viable project to the operating, market, and safety risks and uncertainties attached to a developed mine. Since we cannot totally escape the risk and uncertainty related to resource projects, as an industry we should improve our presentation of the upside and downside risks in the context of the project?s development path and maturity. More transparent, consistent, and balanced views of technical confidence will better inform both internal and external stakeholders about the expected risk in the project. International reporting codes set out the minimum standards, recommendations, and guidelines for public reporting of Exploration Results, Mineral Resources, and Mineral Reserves. However, the reporting code principles of transparency and materiality are largely subject to the interpretation of the competent person(s), which may introduce a degree of subjectivity in reporting, particularly the level of disclosure regarding supporting information. It is fundamental that Mineral Resources, Mineral Reserves, and study outcomes are reported so as to unambiguously present the level of inherent technical uncertainty (or confidence) in a project, while conveying a balanced view of the opportunities a project presents. Reporting needs to consider various stakeholders who may rely on this information, and present the data in the context of the changing risk profile associated with project development paths and project maturity. This paper discusses the interdependence of resource-to-reserve conversion, the consideration of various technical-economic study types, and the level of confidence conveyed to stakeholders relying on these technical reports and other company public announcements.

Jan 1, 2014

By Henk van der Bijl, Sean Rogers, Eugene Sidorski, Alan Carpenter

The electrode column is the heart of the submerged arc furnace. Superior electrode performance provides improved furnace performance. This paper describes the main features of the electrode column that delivers superior performance in furnaces worldwide, developed by Pyromet. Pyromet?s electrode comprises the compact slipping device, lower electrode assembly, upper and lower mantles, self-adjusting electrode seal, paste heaters, and Pyromet?s patented innovative electrode breakage detection and length determination system. Pyromet?s slipping device features compact interlocking clamping rings, incorporating fail-safe spring-loaded design. The interlocked clamping rings distribute the clamping force over a larger area of the electrode casing, preventing damage. The slipping device assembly features a low maintenance modular design that allows rapid slipping cycle times, back slipping, and compatibility with Pyromet?s electrode breakage detection and length determination system. Pyromet?s lower electrode assembly consists of the contact shoes, pressure bellows, pressure ring and heat shields. The contact shoes and pressure ring are designed for long, trouble free operation whilst the pressure bellow configuration equalise contact pressure and current distribution. Furthermore, the contact shoes incorporate a self cleaning feature, ensuring optimum electrical contact. The segmented design offers easy maintenance. Pyromet?s clients experience less down time due to longer component life. Pyromet?s remote adjusted electrode seal assembly reduces the rope seal working temperature, increasing rope life. The self compensating rope seal clamping force ensures an effective seal as the rope wears. Pyromet?s electrode breakage detection and length determination system detects electrode breaks utilising Pyromet?s electrode holder and data processing system. The length measurement system controls electrode length, eliminating the occurrence of short electrodes. The length measurement system furthermore eliminates the need for manual electrode length measurement, reducing associated production losses during furnace burn downs.

Jan 1, 2007

By Bruce Hebblewhite

Australia’s Minerals Tertiary Education Council (MTEC) has achieved several successes during its first three years of operation. This initiative was developed through the Minerals Council of Australia, in conjunction with three partner universities involved in mining engineering education. The partner universities are the University of New South Wales (UNSW); Curtin University, the West Australian School of Mines (WASM); and the University of Queensland (UQ). The collaboration between these partner universities and industry has led to the development of shared course material, cross-institutional teaching arrangements, and the development of a number of flexible, distance-based delivery programs. This article then discusses future initiatives. Importantly, the challenge is the future initiative planned to cement this collaboration by the formation of a “virtual” national school of mining engineering: Mining Education Australia (MEA). This will provide a common third and fourth year program to all three universities beginning in 2007. The common program will involve innovative teaching and learning arrangements, greater student exchange potential and a more significant input by industry into the education process.

Jan 1, 2006

In the Bendigo district, with its large number of comparitively small leases worked by separate companies, we might naturally expect to find many different arrangements of winding machinery and, as a matter of fact, there are steam winches, old portable engines, single and duplex geared engines, twin engines on the first motion, and in one instance a single engine on the first motion, all employed for hauling purposes from depths of 1000 feet and over.It would be impossible in the compass of this paper to discuss at all fully the various arrangements of winding gear employed on the field the writer can simply refer to some of the more prominent features, in the hope that the information may prove of interest and benefit to the mining community. In criticising our machinery it must be remembered that when many of the plants in use at the present time were erected, they were not intended to wind from more than one third of the depths now common on the field; but so long as the machine could be made to haul a tank of water from the bottom of the shaft it has remained, the greater power required being obtained by increasing the piston speed and altering the gear wheels to suit. The consequence is, of course, that in some of our mines the speed of winding is painfully slow this feature, however, though certainly not consistent with modern ideas of economical mining, does not so seriously affect Bendigo as it would other fields, for the comparatively small quantity of stone to be raised from a given reef by some...

Jan 1, 1902

By Stephen R. Iverson, Bill M. Stewart, Michael J. Beus

The U.S. Mine Safety and Health Administration (MSHA) has identified ore pass hazards as a significant safety problem in underground metal mines in the United States injury and fatality data show that many injuries are related to pulling or freeing ore pass chutes and structural failures of control gates and ore pass walls. Researchers at the Spokane Research Laboratory of the National Institute for Occupational Safety and Health are investigating these hazards and developing methods to improve safety during transport of ore and waste. Particle flow analysis methods were used to simulate chute and control gate response to various material loading scenarios. Results from computer models indicate that dynamic impacts from ore and waste rock might be considerably greater than theory predicts. Static and dynamic loads were measured in a laboratory setting using scaled ore (sass mock-ups. Field tests were initiated in an active ore pass to determine actual static and dynamic loads. Field data were compared to computer results and indicated that impact and total static loads were substantially less than the computer model results suggested. Damping factors, normal and shear stiffness, and mass frictional characteristics have a significant effect on particle flow and resulting impact loads.

By Ian Thomson

The Social License to Operate ? We are operating in an era where social license in the resource industry is as important ? if not more important ? than mineral potential ? Concept proposed by Placer Dome executive Jim Cooney in 1997 as essential requirement for the future survival of the mining industry ? ?You don?t get your social license by going to a government ministry and making an application or simply paying a fee? It requires far more than money to truly become part of the communities in which you operate.? Pierre Lassonde, President of Newmont Mining Corporation (2003). What it is ?Granted by the local community ? Intangible, informal, non-permanent ? Has to be earned and then maintained ? Defined as ? Ongoing Acceptance (a lower level) ? Ongoing Approval (a higher level) ? Expression of the quality of the ?relationship?

Aug 1, 2013

By G. Ward Wilson

Waste rock and tailings may be combined through intimate blending to create new materials with superior physical and hydraulic properties. The new material, termed Co-Mix, has high shear strength characteristics, low compressibility, low hydraulic conductivity, and a high water retaining capacity. Co-Mixed tailings and waste rock may be used to construct cover systems, internal barriers and seals, confinement structures and full depth waste repositories. Field scale test trials using Co-Mixed blends of waste rock, tailings and slag have been constructed at the Copper Cliff Mine in Sudbury, Canad. These lysimeters will be used to evaluate the performance of the new material for cover systems that may potentially be constructed on the tailings impoundment upon closure. In this sense, the paper point out the construction of the lysimeters with respect to expected field performance during the spring snow melt period and summer to produce cover systems for closure.

Sep 12, 2005