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By Derek. C. Arnold

In order to meet increasing demands for water supply in the next millennium, the Government of the Hong Kong Special Administrative Region have identified the need for a major new water treatment and transfer scheme. The project now under construction will comprise a 1.2 km long raw water aqueduct, a major new 0.25million cubic metres per day water treatment works (with space for upgrading to 1.2Mm³/d), a 12.1 km long treated water aqueduct and a primary service reservoir. In order to meet increasing demands for water supply in the next millennium, the Government of the Hong Kong Special Administrative Region have identified the need for a major new water treatment and transfer scheme. The project now under construction will comprise a 1.2 km long raw water aqueduct, a major new 0.25million cubic metres per day water treatment works (with space for upgrading to 1.2Mm³/d), a 12.1 km long treated water aqueduct and a primary service reservoir.

Jan 1, 1999

By Frank W. Luerssen

Introduction "Austerity" is perhaps an overly generous description of the past three years in the American steel industry. Steel plants operated at an average of only 57% of their capability in 1982-84. The dismal losses for last year are still being totaled. But during the two years before this period, American steelmakers recorded an aggregate net loss of a staggering $6.8 billion. Steelmakers responded by closing numerous marginal facilities. And production capability was cut by 13.6 Mt (15 million st). Capital expenditures still averaged $2 billion annually. But this was inadequate to maintain the existing base of steelmaking facilities. The general economy experienced a satisfactory recovery during this period. American steel, however, continued to suffer from a lagging recovery in the capital goods sector. This was due to record penetration of its domestic market by imports and from very weak realizing prices on the volume that was available. In addition to the direct influx of offshore steel products - which itself depressed prices - the industry also became painfully aware of the growing importance of "indirect" imports. These came in the form of steel-containing producer and consumer durables. Industrial equipment and autos fabricated from foreign steel accounted for the equivalent of 6 Mt (6.5 million st) of lost market opportunity for domestic steel-makers last year. That is over and above the 23.5 Mt (26 million st) of direct steel imports. Given these factors, Inland Steel was not spared from the threeyear downpour of red ink. Despite its record of continuing modernization in steel, our single-plant location in the world's best steel-consuming market, and the high proportion of consumer durables related products, such as cold rolled and coated sheet in our mix, Inland suffered aggregate losses of $277 million during the 1982-84 period. Strategic Planning The foregoing establishes a perspective - a base from which we have restructured our view of the steel industry, and of our own role within that picture. Until possibly two years ago, this present weakness in steel demand was viewed around the world as an aberration, eventually to pass. By contrast, it is now recognized that austere times are the normal steel environment. The topic here is management of resources. This implies an emphasis on strategic planning. It is worthwhile to examine some of the more critical assumptions that were driving strategies among a number of steel companies just before the 1980s. Those projected characteristics of the future steel environment were arrived at through painstaking analysis. They were carefully and heavily quantified and were generally shared by outside observers and our peers within the steel industry. • First, the assumption was made that domestic steel demand would continue to grow at an average rate of 2% per year. • Second, it was assumed that this growth in the American market would continue to be filled predominantly by US mills. It was believed that increases in steel and steel-related demand overseas would absorb much of the ominously growing capacity of third

Jan 6, 1985

By E. F. Schnitzer

During 1996 and 1997, Oregon experienced flooding on a scale not seen in many years. Some gravel pits located near rivers experienced erosion. In several cases, breaches occurred between the gravel pit and the river. Initial evaluation of several sites that experienced these breaches showed that impacts to the river system were complex and varied significantly from site to site. The impacts to the adjacent river system may be viewed as positive and negative. Several flood-plain-mining sites in Oregon located in areas of historic river flow reverted to active riverbeds. In many cases, state and federal fisheries biologists and university researchers saw the resulting increase in channel complexity and habitat as favorable. The Oregon Department of Geology and Mineral Industries —Mined Land Reclamation Program (DOGAMI-MLR) is studying the effects to the off-channel areas that resulted from the 1996 floods. More data is needed to make sound flood-plain decisions regarding mining.

Jan 1, 1999

Adverse ground behavior events, such as convergence and falls of ground, are some of the most significant challenges and hazards in underground mines. Our goal is to work toward mine-wide, digital, and real-time three-dimensional geotechnical situational awareness and predictive capabilities in complex underground mining operations. This will benefit operators, engineers, and management by enabling them to develop a more proactive approach to ground control. To this end, and inspired by research in the field of remote sensing and autonomous robotics, this paper assesses the potential of mobile light detection and ranging (LiDAR) data acquisition for high-frequency, high-accuracy monitoring tasks in Global Navigation Satellite Systems (GNSS) deprived underground mines. Limitations of current monitoring practices are reviewed. Relevant academic and commercial developments in the fields of indoor mobile mapping systems (MMSs) and simultaneous localization and mapping (SLAM), robust autonomous robotic platforms, and automated remote sensing data processing are highlighted, and their current shortfalls are evaluated. To conclude, the ramifications of this work for the development of future autonomous underground mine monitoring solutions are discussed.

Jul 28, 2020

By F. F. Peng

The raw-coal feeding system and the upward medium current flow in a dense-medium vessel (DMV) are, in addition to the residence time of particles in the separator, important factors for efficient coarse particle separation. The feed material from a raw coal screen and/or pre-wet screen merge with the major volume of circulating medium as push medium, guided by an adjustable submergence baffle plate deep fed into the separator for effective separation. The remaining volume of the circulating medium enters from the purge and drain hoppers at the bottom of the DMV. This generates a gentle upward medium current flow in the separator, which prevents dense medium stratification/settling and merges as part of the push medium. A two-dimensional, two-phase model developed using computational fluid dynamics (CFD) is used to describe the flow pattern and evaluate the function of the dip plate for understanding the mechanisms of particle separation in the separator. The particle movement in the DMV is also tracked to investigate the major operating parameters affecting the separation performance of the DMV. The simulation results of the DMV separation performance are validated by in-plant test data.

Jan 1, 2007

By B. Weyerman

U. S. Steel's Oak Grove Mine experienced several top hinge failures on their caving shields. It was determined that all the caving shields needed to be replaced with new caving shields before more thilures occurred. The cost and amount of time needed for several scenarios of caving shield change outs were compared. This paper discusses how Oak Grove Mine decided to and did change 126 caving shields in six specially designed jig stations underground during a longwall move using their own UMWA employees.

Jan 1, 2001

By D. W. Partridge, W. Lamb, A. E. Lamb, S. Bird

Due to the constant need to improve SAG mill performance and efficiency, extensive research into all aspects of SAG mill optimization has been performed. This paper will review the current evolution of SAG mill shell liner design and their performance at the Copperton Concentrator. The effect of these liner design changes will be discussed with respect to: • Liner configurations • Mill operating performance, i.e., throughput, power draw, mill control • Mill mechanical performance, i.e., liner wear profiles, liner life, liner breakage, liner hardness • Foundry manufacturing considerations • Economic evaluation of throughput versus liner life This paper will discuss the results of Kennecott Utah Copper’s (KUC) and ME International’s (MEI) test work, providing an insight into the past, present and potential future opportunities of SAG mill liner design.

Jan 1, 2002

By Thomas J. Crocker, Douglas B. Uthus

Tunnel Boring Machines (TBM) have gained worldwide acceptance in the construction field and are being employed in ever increasing numbers to drive underground transit lines, drainage systems, etc. However, TBM utilization in the mining industry, and more specifically coal mining, has been very limited. This paper reviews past and present applications of TBMs to coal mining and examines the needs of the industry in an attempt to offer some insight as to what a TBM system must provide if the excavation potential demonstrated in civil works projects is to be realized in coal operations. EUROPEAN EXPERIENCE Germany The Germans recognized long ago the potential of mechanized drivage for coal mine entry development. Early in the 1960's experimental runs were made with a full-face Wohlmyer roadheader at the Westerholt Mine and trials were conducted on a roller bit armed full-face Bade roadheader. But because of problems with penetrating the various carboniferous strata occurring in changing sequence and hardness, these first attempts were soon terminated. After viewing later successes in the construction industry with improved TBMs, new attempts were initiated by the German mining industry in 1971 to mechanize drivage of their development entries. Four TBMs of two different types were placed in operation.

Jan 1, 1976

By J. H. Daniel, S. Krzemien

Partners In Economic Reform, Inc., established a Polish-American Mine Center in Katowice, Poland, in 1996 to improve working conditions in the minerals industry. The program was based on the experience of mining companies, government, and labor in the United States, and was executed by a Coordinating Committee headed by the Center Director and Polish leaders from industry, State, labor, and academia. The cooperation among all parties has enabled safety and health issues to become part of industry restructuring with impressive initial reductions in coal mine fatalities. Existing work practices and attitudes of labor and management were assessed in coal mines throughout the country. Promotion, Rules, and Job and Task Analysis were identified as the areas requiring the most improvement, and are part of a post-graduate Safety Management program. Demonstration projects included measuring dust levels, using safety glasses, and promoting hazard awareness. Improved labor-management relations increased cooperation allowing for effective transfer of technology. Results can also be applied to improve the working environment of the manufacturing sector also undergoing restructuring.

Jan 1, 2001

By Bryan Ulrich

Rroundtable 2009, a Knight Piésold and Co.-hosted roundtable discussion on mine closure and cover design was held at the Red Lion Inn and Casino in Elko, NV on Feb. 12, 2009. Knight Piésold?s Bryan Ulrich and Steve Boyce, as well as Knight Piésold representatives Cynthia Parnow and Corey Conrad from Denver, CO, and Rick Frechette from the Tucson, AZ office were on hand to help facilitate the discussion. The meeting played host to approximately three-dozen attendees from four states. Attendees included personnel from seven mining properties and attendees from corporate offices. The majority of attendees were people directly involved with environmental work on a day-to-day basis. Other attendees were project managers whose jobs involve some level of environmental focus. The purpose of Roundtable 2009 was to exchange ideas and information pertaining to mine closure and cover design associated with almost any aspect of a mining operation. This type of forum provides a less inhibited format for discussion, when compared with traditional conferences and symposia. In the roundtable format, lively discussions are encouraged. This discussion was the fourth in the series of Elko Roundtable events. Previous roundtables pertained to heap leach pad design, construction and operation; design, construction and operation of tailings storage facilities and site-wide water considerations. The initial subtopics for Roundtable 2009 included:

Jan 1, 2009

By K. R. Griffin

Explosions in underground coal mines have been a serious safety concern since the advent of mining; despite significant technological advances, they are still occurring. Parameters such as barometric pressure, geological changes, and changes in ventilation can contribute to an explosion. These factors can be monitored with available and developing technologies to create algorithms that predict when explosions are more likely to occur. This paper reviews current underground atmospheric monitoring systems and related regulations around the world. In addition, suggestions for improvement and implications for explosion prevention are discussed.

Jan 1, 2011

By M. Leslar

Slope monitoring has been an important issue in static terrestrial lidar for some time. Several solutions for monitoring the progress of a slide have been devised over the years. All of these solutions have required users to be in the field operating the lidar equipment. This paper presents a new system developed using the Optech ILRIS-HD or ILRIS-LR lidar and the scripting language of PolyWorks to produce an autonomous slope monitoring system. This system has proven invaluable in detecting and alerting mine workers to potential danger within their mine sites. It has already been deployed in two mine sites and is scheduled to be installed at a third.

Feb 27, 2013

By Verya Nasri

This paper presents analysis of damages and rehabilitation design for three major French rail-way tunnels built in mid-19th century. The La Nerthe tunnel underwent ovalization deformation with excessive displacement at the springline, and pinching and bursting of the liner bricks at the crown due to tectonic residual stresses with very high lateral earth pressure. The Saint-Louis les Aygalades tunnel invert was subjected to undulatory deformation resulting in tracks misalignment, which was caused by non-homogeneity of mechanical and hydraulic properties of the ground. The Roches de Condrieu tunnel required widening to comply with the increase in dynamic envelope of trains due to their larger cross section and higher speed. The applied rehabilitation methods and constraints of work in these busy mainline railway tunnels have been discussed in detail.

Jan 1, 2008

By Rex E. Loesby

The marble deposits of Yule Creek were first discovered in the late1870s. Minor quarrying occurred between that discovery and the early 1900s. Major development occurred in 1905, when Channing Meek, with some help from the Rockefellers, raised $3 million to develop the Colorado Yule Marble Quarry. That is $50 million in today’s dollars. Some of the words used to describe the marble deposit were “gigantic, remarkable, flawless and immense.” Boosters proclaimed, “The marble age is here.” Obviously, dreams were big for Marble.

Jan 1, 2003

By Lane White

In mid-April 1992, MINING ENGINEERING mailed a survey questionnaire relating to mining shovels and hydraulic excavators to 125 SME members working at surface mines or at the headquarters of companies that operate surface mines. The mailing was directed to individuals whose titles indicate that they have management or mine planning responsibilities for surface mining operations. A total of 56 usable surveys returned by June 17 are the basis of this report. Precious metals mines Eighteen precious metals mines or mining companies returned completed surveys in time to be included in this report. Of these, 14 use hydraulic shovels only for both ore and waste, I uses both hydraulic and rope shovels, and 2 use Caterpillar 988 front-end loaders for both ore and waste. (Of the latter 2, neither expects to be in the market for a shovel in the next three years. I of these 2 placed Harnischfeger P&H number one and O&K number two in response to the question, "Based on your current knowledge of their machines, which manufacturer would you likely chose to supply new shovels or excavators to a mine or mines operating under your responsibility, if you were in the market?") Another uses front-end loaders, make not designated. The latter does not expect to be in the market for mining shovels or excavators within the next three years. Of the final total of 14 precious metals mines using only hydraulic excavators to load ore and waste, 8 use Hitachi excavators only, 1 uses Demag excavators only, 1 uses Liebherr excavators only, 1 uses O&K excavators only, 1 uses Harnischfeger P&H and O&K excavators, 1 uses Harnischfeger P&H and Hitachi excavators, and 1 uses Hitachi and Demag excavators. Of the 14 precious metals mines using only hydraulic excavators, 7 use excavators in the 7.6 to 11.5 m; (10 to 15 cu yd) size range. Of these 7, 5 use only excavators in this size range, and they are used to load both ore and waste. 1 of the 7 also uses 11.5 to 17 m' (15 to 22 cu yd) excavators, and I also uses a 17 to 23 m3 (22 to 30 cu yd) excavator. Of the 7 remaining of these 14 precious metals mines that use only hydraulic excavators, 3 use 11.5 to 17 m' (15 to 22 cu yd), 2 use 17 to 23 m3 (22 to 30 cu yd), and 2 use less than 7.6 m' (10 cu yd) units.

Jan 1, 1992

By F. Burat

Large reserves of feldspar ore exist in the Aegean region of Turkey. The main colored impurities in these ores are iron- and titanium-bearing minerals such as anatase, rutile, sphene and ilmenite. In this study, a potassium feldspar ore containing mainly quartz and coloring impurities was subjected to beneficiation tests involving magnetic separation and flotation, which were applied either separately or in combination. Bench-scale flotation experiments using cationic collectors G-TAP and Flotigam V-4343 and using HF and H2SO4 as modifiers were employed to separate feldspar from quartz and to remove part of the titanium impurities. The best results were achieved with a combination of high-intensity wet magnetic separation and flotation. A feldspar concentrate containing 16.28% Al2O3, 10.75% K2O, 2.84% Na2O, 69.97% SiO2 and 0.16% Fe2O3 was produced. A quartz concentrate containing 2.30% Al2O3, 0.48% K2O, 0.42% Na2O, 0.07% Fe2O3 and 96.20% SiO2 was also obtained

Jan 1, 2007

By F. Calizaya

The Western Mining Training and Translation Center is a consortium of four universities devoted to developing educational and training projects to reduce the incidence/accident rates in the mining industry. The center consists of Missouri University of Science and Technology, Montana Tech, the Colorado School of Mines and the University of Utah. It is fully funded by the National Institute for Occupational Safety and Health (NIOSH). The center manages 15 educational projects and one translation project. Hazard Identification and Risk Assessment (HIRA) for Small Mines is an educational project managed by the University of Utah. The objectives of this project are to identify critical mine hazards, assess risks; outline procedures to reduce accident/incident rates in small mines in the western United States and to train mine workers and super-visors on HIRA in each participating mine. To accomplish these objectives, the HIRA personnel visited 15 small mines in Utah, Colorado, Nevada and California. At these mines, most operators were employing independent contractors to perform several tasks ranging from drilling, blasting and mucking of rock at the work site to hauling ore to a processing plant. The operation of diesel-powered equipment was one of the major tasks performed by the contractors. This article presents three case studies in which contract workers performed a number of tasks with no reportable incidents but did so unsafely. It also highlights the training received by most contractors, the constraints imposed upon them and the safety hazards to which they are exposed most frequently.

Jan 1, 2008

By David S. Yang, Osamu Taki

The innovative Soil-Cement Mixing Wall Technique, developed independently in Japan, consists of mixing in-place soils with cement grout using multi-axis augers and mixing paddles to construct overlapping soil-cement columns. The applications of overlapped soil-cement columns include cutoff walls for groundwater control and structural diaphragm walls for excavation support. The special features of this technique include water tightness, versatile strength design, and efficient installation in subsurface materials varying from clayey soils to cobbles or soft rocks. Through the introduction of two recent subway projects in Japan, this paper presents the design parameters, construction procedure, quality control and performance of soil-cement wall for excavation support and groundwater control.

Jan 1, 1989

Several economic factors have caused the surface mining industry to require large-capacity shovels and trucks for efficient, high-production, low-cost operations. Some of those factors include technological advancements in equipment, commodity market depressions, increased labor and maintenance costs, contractural obligations and harsh operating conditions. The difficult operating conditions in surface mines, however, pose challenges to the use of high-capacity equipment. They include space limitations, weak over-burden, and weathered soils and rocks. So mining companies face major challenges in selecting appropriate shovels to meet the technical, operating, safety, environmental and economic requirements of their mines.

Jan 1, 2003

Magnetic separation is an age-old technique for mineral beneficiation operations. The existing mathematical models for magnetic separators are quite complicated, and it is very difficult to measure the theoretical separation efficiency. The connectionist approach of modeling, to establish the relationships of the inputs and outputs, is preferred for this kind of problem. Experiments were carried out on a high-intensity roll magnetic separator to develop a database using four input variables (magnetic flux intensity, particle size, splitter position and roll speed) and two output variables (weight recovery and Fe recovery). The artificial neural network (ANN) and statistical methods (MLRG) were used to model the magnetic separation process. For the ANN, the regression coefficient (R2) values between the predicted and measured results were 0.89 and 0.94 for Fe recovery and weight recovery, respectively. Compared to ANN, the multivariable linear regression analysis showed inferior performance in predicting the weight recovery and the Fe recovery. The ANN models for the roll magnetic separator can predict the separation efficiency up to an acceptable limit. These models can be used to modify the operational parameters at mineral beneficiation plants to minimize the effects of variations in the raw material characteristics.

Jan 1, 2009