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By Luminita Calin

King County (Seattle, WA) is on a monumental task of building the new Brightwater System complete with a new treatment plant, three main conveyance tunnels, a new outfall into Puget Sound and other ancillary works. This paper will describe the first conveyance tunnel, Brightwater East currently under construction by the Joint Venture of Kenny (Sponsor) / Shea / Traylor that is scheduled for completion in early 2010. The project located in Bothell, WA (north of Seattle) is in both King and Snohomish Counties. It was the first of the major tunnel projects that was scheduled by King County for the Brightwater System. The East Contract consists of the following major elements: 14,000 ft of 19'-2' EPBTBM mined tunnel using 16'-8' ID bolted, gasketed precast concrete segments for a primary liner; installing and encasing 14,200 ft each of 48', 66', 27', 84' in diameter steel pipes inside the tunnel along with three runs of fiberoptic cable; 2,430 ft of 72' in diameter microtunnel including three caisson shafts and associated structures; one Intercepting Structure (IS) shell to mine from that is 74 ft deep and 74 ft finished in diameter with 130 ft deep slurry diaphragm walls, tremie slab and final concrete wall lining; one Influent Pump Station shell (IPS) 83 ft deep, twin 77 ft inside diameter cells, with 160 ft deep slurry diaphragm walls, tremie slab, and final lining; two short 12 ft in diameter inter-shaft connector tunnels; one extraction shaft 40 ft deep by 40 ft wide and 140 ft long for connection to the new treatment plant piping.

By R. Hipsley, D. Arbonies, P. J. Dobak, M. Visher

The Storm deposit is a high grade breccia hosted “Carlin-type” gold deposit located at the north end of the Carlin Trend. Storm consists of 3 smaller deposits: 1) 49er Zone, 2) End Zone, 3) Discovery Zone. Structural intersections and favorable stratigraphy at the Paleozoic Popovich/Rodeo Creek formation and Bootstrap limestone formation contact are the primary known controls to gold mineralization at Storm. High grade silica-sulfide breccia occurs in the footwall of the north-south trending, dike filled, Dee fault. This mineralization cross-cuts silicified heterolithic breccia zones localized above the Bootstrap limestone where northwest, dike filled, reverse faults cut this structural-stratigraphic horizon. 40Ar/39Ar dates of 37.57+ 0.34 Ma (basalt dike) and 162 Ma (lamprophyre dike) have been obtained from dikes in the Dee pit which are locally mineralized by the same event as Storm. This paper will focus on the descriptive aspects of the Storm deposits.

Jan 1, 2001

By L. L. Lacerda, A. J. Blair

The Wolf Creek Upper Narrows Tunnel (Upper Narrows Tunnel) is one of the first major highway tunnel in the United States implementing the use of spray-on membrane for purposes of constructing a double-shell drainage solution between an initial shotcrete lining and a final cast-in-place concrete lining (Figure 1). In the case of the Upper Narrows Tunnel the primary membrane is constructed with a spray-on product manufactured by Degussa, namely Masterseal® 340 FA (MS 340) that has been utilized previously in other tunnel projects. Shotcrete-like in application, but differing in physical properties, MS 340 is now outdated, and is succeeded by Masterseal® 345 (MS 345), a nearly identical product, with improvements in material properties. Tunnel project histories utilizing either MS 340 or MS 345 are discussed and summarized with regard to the respective motives for prompting spray-on membrane selection and the realized benefits resulting from spray-on membrane construction. With an emphasis on the Upper Narrows Tunnel, project summaries discuss details of the aspects of design for spray-on membrane construction methodology as opposed to conventional sheet membrane construction methodologies. It is anticipated that experience gained during the construction of the Upper Narrows Tunnel with respect to other tunnel projects that have utilized spray-on membrane will be of use for future tunnels employing spray-on membrane in drainage solutions.

Jan 1, 2005

By I. Tsolas

This paper presents the use of non-parametric approach (i.e., data envelopment analysis, DEA) for the development of environmental sustainability indicators in mineral processing using environmental, economic and/or integrated indicators (i.e., indicators that interrelate two dimensions of sustainability). A case study based on real publicly available data is presented to illustrate how the proposed approach can be implemented in practice. The merit of this approach, which is based on the productive efficiency framework, is that it provides environmental sustainability indicators that can be used internally for benchmarking purposes and externally for sustainability reporting.

Jan 1, 2008

By K. C. Tran

This paper reviews the advancement of measurement technologies for the control of raw materials processes in the basic industries. The combination of digital technology and on line spectroscopy enables the development of intelligent instruments for composition and particle size analyses in real- time high- frequency control conditions. In many industries, the applications result in productivity improvement and energy savings. Plant specific examples include operating experience and benefits realized in sorting, blending and beneficiation processes. Instruments of the future not only measure specific parameters of the process and monitor its own health combined with self-corrective mechanics but also acts with intelligence to effect the quality of the process or regulate the primary apparatus.

Jan 1, 2001

By Liming Yuan, James Rowland, Lihong Zhou, RICK THOMAS, DAVOOD BAHRAMI

Continuous monitoring of carbon monoxide and other fire-related parameters by means of an atmospheric monitoring system (AMS) has been used by the mining industry for early fire detection in underground mines. The National Institute for Occupational Safety and Health (NIOSH) initiated a project to integrate real-time AMS sensor data with NIOSH’s mine fire simulation program, MFIRE 3.0, to simulate and predict the spread of smoke that would provide assistance to mine fire emergency response personnel. Determining the heat release rate of a fire using the monitored sensor data was a critical component of the successful completion of this project. NIOSH researchers developed a direct method to calculate the heat release rate when a fire is within close range of sensors. However, this method is only applicable to the case where a fire occurs in AMS-monitored airways. This paper presents an improved method for determining the fire heat release rate for complicated scenarios where a fire is distant from sensors and airflow splits and merges are present. The method was validated using a fullscale diesel fuel fire test conducted in the Safety Research Coal Mine at the Pittsburgh Mining Research Division and can help mine operators and safety personnel make informed decisions during a fire emergency.

Jul 31, 2020

Based on X-ray phase analysis and exploratory experiments, a new technology was developed to recycle multiple valuable elements in spent Al2O3-based catalyst. The experimental results showed that after roasting at 750°C for 30 minutes at an Na2O:Al2O3 mol ratio of 1.2, the leaching recoveries of alumina, vanadium and molybdenum from the spent catalyst were 97.2%, 95.8% and 98.9%, respectively. Vanadium and molybdenum in sodium aluminate solution can be recovered by barium hydroxide and barium aluminate. The precipitation recovery of vanadium and molybdenum was 94.8% and 92.6%, respectively. Al(OH)3 is prepared from sodium aluminate solution using the carbonation decomposition process. The purity of Al2O3 is 99.9% after calcinations, and the recovery of alumina can reach 90.6% in the whole process. The Ni-Co concentrate was leached with sulfuric acid, and a nickel recovery of 98.2% and a cobalt recovery of more than 98.5% were obtained under the experimental condition of 30% (w/w) H2SO4, 80°C, a liquid: solid ratio of 8:1 (by weight), a reaction time of 4 hours and a stirring rate of 800 rpm.

Jan 1, 2007

By Michael Taylor, Thomas W. BoBo

Currently two of the most important characteristics of construction aggregates are (a) the particle size distribution (psd) and (b) the “shape” of the aggregate particles. The long established test methods and standards for these properties require substantial resources and most suppliers can take samples and conduct tests at intervals measured in days (psd) or even months (shape). Furthermore these tests require time: so the results are available only after material has been stockpiled or shipped. In the rare cases where problems are found the out-of-spec material has often been shipped to points unknown. There are substantial advantages to be obtained if the psd and other geometrical properties could be obtained from the material as it moves through the production processes and if the results could be reported back within seconds or minutes to Plant Control Managers. This paper describes a single on-line system used to evaluate production of crushed material in a production quarry. The system consists of an enclosure (containing the camera and lighting etc.) mounted over a production belt. Images are fed by fiber optic cable to a nearby control room where the data are analyzed; stored; displayed; and made available for integration into a process control system. Numerous forms of display can be created according to the needs of the producer. Once programmed by an automation engineer all functions of operation are fully automated. The system has permitted over 400 tests per hour with a feed back time less than 2 seconds. Sufficient geometrical measurements are made so that many different “shape” factors can be computed on a similar time scale. The paper summarizes the results from approximately 100 shifts of about 8 hours each and compares the imaging method with the current standard hand methods. Study of the data generated showed that, when combined with additional plant information, the system can be used to generate additional useful control information.

Jan 1, 2005

By S. Devasahayam

Acid production or acid drainage is a major environmental issue that also has negative implications on the aquifer system surrounding the mine tailings area. The approach to controlling acid mine drainage involves physical and geochemical characterization that affect acid production. The material permeability determines the availability of oxygen, which is paramount in acid production in coal rejects, and varies with depth. In this paper the author presents the variation in oxidized pyrite/acid production with depth in black coal mine washery wastes. Chemical kinetic parameters and the diffusive parameters have been used to obtain the variation in oxygen content and the oxidized pyrite content with respect to the depth and time. Its dependence on porosity and moisture content is illustrated.

Jan 1, 2007

By James A. Pendleton

In response to Public Law 95-87 (SMCRA), Colorado promulgated regulations governing the mining of Coal. These regulations require the prediction, monitoring and mitigation of "material damage" caused by subsidence. All permitted underground coal mines within Colorado have approved subsidence programs. Preliminary monitoring results indicate the subsidence mechanical predictions have been sufficiently accurate to preclude material subsidence damage. The State of Colorado has developed a practical approach to regulating subsidence, which stresses monitoring verification of predicted subsidence phenomena. However, shortcomings exist in our ability to precisely predict the secondary consequences of subsidence, including effects to structures, the hydrologic balance and the environment. Lack of accuracy in predicting these secondary consequences results in uncertainty, necessitating conservatism in permitting. To avoid increasingly stringent permit restrictions, future research should emphasize the secondary consequences of subsidence.

Jan 1, 1986

By Hyung-woo Kim, Sup Hong, Sung-Soo Kim, Chang-Ho Lee

A deep-seabed integrated mining system, which consists of four subsystems such as riser pipe, buffer, flexible riser, and tracked vehicles, is presented in Figure 1. In order to collect more manganese nodules, multiple tracked vehicle systems should be used in a deep-seabed integrated mining system.

Sep 1, 2014

By William Stewart, John Tinkler, Gary B. Hemphill

Of the 345 km long Taiwan High Speed Rail Project, connecting the cities of Taipeiand Kaohsiung, the 23 km alignment on Contract C230 required the construction of5755 m of shallow mined tunnels ranging from 137 m to 1285 m in length. All nine of these tunnels were mined using NATM methodology. On September 6, 2002, a collapse occurred in Tunnel T08 that affected approximately 50 m of tunnel. There was little warning. However, the crew was evacuated approximately 45 minutes prior to failure and thus, no injuries or loss of equipment. This paper will discuss the mining methods, jet grouting ground support, and the instrumentation selected for the rehabilitation and monitoring of the tunnel.

Jan 1, 2005

By M. Martins

This work presents and discusses the influence of the surface tension (gLV) of methanol/water mixtures on the flotation response of apatite versus gangue minerals conditioned with flotation reagents (75 g/t cornstarch and 100 g/t Berol 867) at pH 10.6. Berol 867 is a collector composed of sodium alkyl sarcosinate plus nonionic surfactant. The highest Schulz efficiency of separation (recovery of apatite minus recovery of gangue) was achieved at ?51.0 mN/m. The critical surface tension of wettability (gC) of apatite was found to occur at 34.7 mN/m when determined by means of gamma flotation experiments, and it was 33.9 mN/m when determined by Zisman?s approach.

Jan 1, 2009

By D. Caiden, C. S. Covil, P. J. Chamley

The paper describes the background to alternative delivery models, drawing on international experience, and introduces Project Alliancing/Contract Partnering, common risks and risk sharing on tunnel projects. A plea for early contractor involvement in design is made before describing some whole life design implications for tunnels. The paper concludes with four short case studies; Channel Tunnel Rail Link in the UK, Hull Waste Water Tunnel in the UK; Island West Sewage Transfer Station in Hong Kong, and the New Southern Railway in Australia.

Jan 1, 2005

By Bob Munz, Ry Stone

To facilitate the installation of the longwall equipment for each extraction panel, West Elk mine develops set-up room roadways that are between 26.5 and 30.5 feet wide. Historically at the mine, the set-up room roadways have been driven in a single 20-foot-wide pass, then incrementally widened to the required width during installation of the longwall shields. The first pass roof is supported with a generic roof support plan consisting of partially encapsulated roof bolts and point-anchored cables. This ground support plan was utilized regardless of the geotechnical conditions encountered in the roadways or consideration of the required stand-up time of the roadway before the longwall shields were installed. This "blanket" approach tends to result in over-conservative or inappropriate roof support designs, particularly in changing geotechnical environments. Guided by the desire to optimize the ground support plans and increase mining efficiency for future set-up rooms, the West Elk mine and Agapito Associates, Inc. have developed and implemented a strata management program. Strata management, as a formal and structured process, allows ground support and mining methods to be tailored to the anticipated and encountered geotechnical environment in a con- trolled manner (Thomas 2007). To arrive at adequate site-specific ground support plans for the set-up rooms at the mine, several struc- tured processes were utilized. Firstly, the geotechnical environment was characterized by examining the roof lithology and geomechanical properties from nearby rock core obtained from exploration boreholes. To increase both mining efficiency and continuity, and to achieve longer stand-up times before the longwall shields are installed, a multi-pass approach was implemented into the design. During mining, the geotechnical conditions of the roadway are mapped, and the roof is strategically surveyed with a borescope. This process was used to ensure that the encountered ground behavior was in alignment with the design standards used for the roof support design. To support this process with measured data, roof extensometers were strategically installed throughout the roadway. This data was used to monitor the magnitude of roof displacement at various horizons and record displacement rates up until the longwall shields were installed. Lastly, a Trigger Action Response Plan (TARP) was used during mining to cater for any unforeseen changes in ground conditions that would warrant additional con- trols such as increased monitoring or the installation of additional ground support. This paper presents two case histories at the mine where the above strata management approach was implemented to arrive at a site-specific ground support plan. The main changes to the mine's ground control plan included a multi-pass mining approach, the utilization of fully encapsulated roof bolts, and the transition to a stiffer roof support system. The geotechnical mapping, the roof borescope results, and the roof extensometer data will be presented to demonstrate the effectiveness of the ground support system up until the longwall shields were installed in both presented cases.

Jun 25, 2024

By A. D. Davis, J. L. Sorensen, C. J. Webb

Environmental impacts from acidic mine drainage are growing national concerns that are particularly acute in the headwaters of the Rocky Mountain region. In the Black Hills of South Dakota, approximately one thousand mines are inactive or abandoned, most of them in the headwaters of major drainages. This paper examines the Bear Butte Creek basin, a heavily mineralized watershed with significant historical mining impacts and a surface gold mine permitted in 1997. The watershed loses its surface discharge to swallow holes in the karstic Madison Limestone. The integrity of the aquatic ecosystem was monitored with a suite of sitespecific bio-indicators. Stream surveys covered the entire reach of Bear Butte Creek from near its headwaters to the swallow holes in the Madison aquifer. Data from the stream surveys, water-quality sampling, and bio-indicator surveys clearly showed that water-quality impacts are limited mainly to Strawberry Creek and to the area of Bear Butte Creek near and downstream of the town of Galena.

Jan 1, 1999

By Michael Lenz

Predictive maintenance technologies including vibration analysis, tribology, infrared thermography, ultrasonic detection, and electrical measurements have been applied to large electric mining shovels. The predictive program was initiated on the P&H Model 2300 and 4100 electric shovels. The utilization of these technologies has shown the potential for improving electric mining shovel availability and minimizing maintenance costs. Predictive technologies provide the tools to assess machinery condition. Availability is enhanced by the condition based planning of component replacement. Maintenance costs are minimized by focusing resources through condition based prioritization.

Feb 24, 1997

By M. Karmis, C. Haycocks

The evolution of longwall mining is briefly traced from its inception in England in the 1620's. In the beginning this method recovered 90% of coal with roof closure controlled by packs and walls. Mechanization began with kerf cutting, crude face conveyors, and improved face support. Full face mining was accompanied by the introduction of self- advancing hydraulic supports. U. S. longwalls evolved a retreating system to recover blocks of coal outlined by room and pillar panels. Computer control combined with the most modern technology have greatly increased productivity. Past trends are used to predict future technological directions.

Feb 24, 1997

By Ira Sohn

This article revisits global projections made in 1981of eight metallic and fertilizer minerals for the year 2000. The objectives here are to quantify the differences between the projected and observed levels of consumption for the year 2000 for eight of the 26 nonfuel minerals covered in the earlier study. An attempt is then made to attribute these (often) large differences to the major determinants of minerals demand — income, technological, regulatory and other policy changes, and changes in the recycling rates of the metallic minerals. The eight minerals covered are aluminum, copper, iron, mercury, nickel, phosphate rock, potash and tin. This summary article presents the actual population, gross domestic product (GDP) and per capita GDP changes from 1970 to 2000, compared with the projected rates for these important determinants of mineral use, along with the observed growth rates of minerals consumption for the eight nonfuel minerals included in this study. When the projections are compared with the observed global consumption levels for the year 2000, the differences range from +43 percent for nickel to +229 percent for potash.

Jan 1, 2005

According to the previous research, it is found that the thickness of cover is mostly less than 100 m for highwall mining system. However, for most of the Chinese surface coal mines, the mining depth is over 150 m; on the other hand, the shovel-truck is the most common mining technology. As a result, a lot of residual coal will be remained around end-walls. Considering these facts, the calculated methodology of highwall mining system under thick cover is presented in this paper. Meanwhile, numerical simulation of highwall mining system under thick cover was carried out. The outcome shows that the calculated methodology for pillar stability of highwall mining system under thick cover presented in this paper is acceptable. In other words, the highwall mining system is feasible to extract the residual coal around end-walls in Chinese surface coal mines. Thus, not only coal recovery ratio can be improved, but also can increase the production life of surface coal mines in China.

Jan 1, 2012