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By Ying Lu, Jeffrey C. Johnson, Chen-Luh Lin, Jan D. Miller, Sindhoora Puvvada

Energy dissipation and fragmentation of rock is of interest for mine-to-mill operations in order to understand breakage and to minimize energy consumption during blasting at the mine site, and comminution at the processing plant. In this regard, high velocity impact breakage of long granite cores, called bars, has been studied with instrumented strain gages to follow the energy dissipation gradient along the bar length resulting from the strain waves generated by impact. As a result of high velocity impact, three zones have been identified (fragmentation, fracture, and elastic) and these three zones have been characterized in 3D using X-ray tomography. The fragmentation zones of the granite bars were studied in detail to describe the particle size distribution and the particle shape characteristics. Finally, the experimental energy dissipation for the fragmentation zone was found to be in close agreement with the expected energy calculated from the Bond work equation, if the anisotropic granite particles are defined by length rather than by sieve size.

By Forrest C. Neil, Clint J. Keifer

The pollution of our water supply, Lake Michigan, is a continuing threat so long as our overflows from combined sewers exist. The problems have become even more acute during recent years, due to the increase of paved area- which accelerates and enlarges the flows of storm water. After each storm, mixtures of raw sewage and storm water spill into our waterways. If the storm is too large for the drainage systems, the mixture backs up into our streets and basements. Under severe conditions, it may even become necessary to open the locks, and discharge the polluted water into Lake Michigan. Consider the scope of the problem, as shown in Figure 1. The area in which combined sewers exist is 375 square miles, located in the central parts of Chicago and 49 suburbs. There are an estimated 640 overflow outlets to the waterways, each requiring attention. The capacity of outlets tributary to the waterways has increased dramatically over the years. Each time a pocket of upstream flooding is drained into the channels, the problem of its rapid disposition increases. Another difficulty is that the bottom of our waterways is covered with a blanket of accumulated sludge, ranging in depth up to 3-feet. This material harms the water quality by depleting the supply of oxygen dissolved in the water ... a final

Jan 1, 1997

By L. Maday, V. J. Perrone, M. B. Gilbert

INTRODUCTION The Brightwater conveyance system project in King County, Washington consists of constructing about 21 km (13 mile) of effluent and combined influent and effluent tunnels. The influent tunnels will collect sanitary sewerage from the service area and convey it to the new wastewater treatment plant (WTP) site at Route 9 in Woodinville, Snohomish County, Washington. The effluent tunnels will convey treated effluent from the WTP to an outfall at Puget Sound. The tunnels will be constructed primarily under residential areas, busy suburban roads and state highways. This 21 Km (13-mile) soft ground tunneling project faced many design challenges because of the geologic and hydrostatic conditions, long tunnel reaches, and large overburden depths. Boring depths typically varied from 45.7 M (150 ft) to 114 M(375 ft) with a maximum depth of 185.6 M (566 ft) deep. Conventional empirical methods for non-mountain terrain based on a 1:1 ratio of drilled footage per foot of tunnel bore (National Research Council, 1984) for evenly spaced borings provided a good start for the Phase 1 explorations. However a continuation of this approach with closer spacing was deemed inadequate by the geotechnical team for efficiently allocating geotechnical exploration resources for the final design. This paper presents a rational approach that was used to evaluate the value of a particular geotechnical exploration boring, pump test or other in-situ test. The method of analysis, which was initially developed for rock tunnels (Einstein et al., 1978), was modified for the Brightwater project. The method considers the potential construction cost risks resulting from variable geologic conditions, the cost and reliability of the geotechnical exploration and the earned value (cost risk reduction) of performing the geotechnical exploration. PROJECT DESCRIPTION In total the land portion of the conveyance system will include approximately21 Km (13 miles) of tunnels ranging in size from 3.0 to 5.2 M (10 to 17 ft) minimum inside diameter with overburden depths of 30.0 to 168 M (100 to 550 ft) and

Jan 1, 2005

By D. M. Muir

Thiosulfate offers a non-toxic alternative to cyanide for processing gold ores. The mechanism of leaching gold using ammoniacal thiosulfate solution is driven by the Cu(II)-Cu(I) redox couple and is complicated by competing ligands such as NH3 and S2O32-. It is shown that an understanding of the copper speciation and sulfur speciation is required to optimise this system. This paper presents Eh-pH and speciation diagrams for varying concentrations of Cu(II), S2O32- and NH3 and discusses the conditions under which various copper and sulfur species are stable.

Jan 1, 2001

The Sandvik DE710 diamond core drill has become one of the most popular exploration drills available. It is operated on exploration and mining projects in locations around the world. The compact nature of the DE710 allows a small footprint on site. This has proven to be a great benefit in difficult access areas where site preparation can be limited. The DE710 drill is available in a range of con-figurations to suit global operational and environ-mental demands. It can be truck-mounted for greater maneuverability and ease of relocating the drill between sites. The drill can also be fitted to crawler tracks, powered from the rig hydraulic system, making it a small, self-propelled unit for areas with difficult site access. And the DE710 is available in a shack-mounted configuration for cold weather applications, ensuring a protected working environment for the drill crew. The DE710 is powered by a 6.7-liter engine that produces 141 kW (190 hp) at 2,200 rpm to power the rig hydraulic system. The engine complies with the Tier 3 emissions standards that are being introduced in many countries. The hydraulic system design for the Sandvik DE710 is based on the company?s philosophy of selecting the best available products to suit the application. The main hydraulic pumps and motors are the variable displacement design. This allows for greater fl exibility and precise control of critical drilling functions. The cooling system has also been designed for operation in ambient temperatures up to 50° C (122° F) to cope with varying global operational demands.

Jan 1, 2009

A dedicated tunnel construction version of the Caterpillar 328D LCR compact radius excavator is proving highly productive on the A9 Autoroute construction project near Visp, in Switzerland. It is the first machine of its kind to operate on a Swiss contract and uses a special dedicated front attachment designed and constructed by German Caterpillar dealer Zeppelin. The machine offers a powerful, stable and compact solution for tunneling contractors. A rear overhang of just 305 mm (12 in.) provides a tail swing radius of just 1.9 m (6.2 ft). The 328D LCR is ideal for the restricted working areas within a tunnel construction site. The machine is equipped with the wide tracks from the 330D L conventional crawler excavator, ensuring maximum stability when operating. In addition, the boom mounting has been moved further toward the center of the machine for the tunnel model, creating an increased lift capacity over the front end compared with a standard 325D L. The boom itself features a robust box section construction, with high-strength steels, additional supporting struts and reinforced bearings for maximum durability. All pins have hard-chromium plating for optimum protection against wear. Stick digging force is a powerful 134 kN, with up to 212 kN of bucket digging force available, for maximum penetration in blasted material. The 328D LCR is also equipped with a heavy-duty dozer blade as standard. This ensures outstanding stability when working and providing a useful secondary tool for clearing and leveling within the jobsite. Two 45° tilting mechanisms in the boom construction, allow the boom to be swung to 45° on either side of the machine. So the specially designed attachment linkage provides increased rollback for access to the roof of the tunnel. A Caterpillar CW45S mechanical quick-coupler allows rapid changes between specialist tunneling attachments, standard Caterpillar buckets and a range of Caterpillar work tools. The machine is powered by a Caterpillar C7 diesel engine. This six-cylinder EU Stage IIIA diesel motor [ ] offers 8 percent more power than its predecessor, with 140 kW (190 hp) available at just 1,800 rpm. Caterpillar?s ACERT combustion technology results in lower fuel consumption and reduced exhaust emissions. However, the tunnel machine is also equipped with a diesel particulate filter as standard, to further cut exhaust gases within the tunnel working. The 328D LCR is designed for use in transport tunnels of 6.8 m (22.3 ft) in height. With the tunneling boom in place, the machine has an operating weight of 42,540 kg (93,783 lbs), yet retains a transport height with the tunnel boom of just 3.9 m (12.8 ft). Transport width with 600 mm (23.6 in.) track shoes, is just 3.2 m (10.5 ft). On the A9 tunnel contract, the machine is being used by a consortium of Swiss and Austrian companies working for the canton of Valais? Routes Nationals Construction (RNC) department. The 31.8-km (19.7-mile) A9 Autoroute construction project will connect Sierre in the west and the town of Brig to the east. The tunnel that is bypassing the town of Visp is just one of a number along the mountainous route.

Jan 1, 2009

By J. Yuan

Ground calcium carbonate (GCC) and chemically precipitated calcium carbonate (PCC) have become important mineral-based commodities in recent years. GCC manufacturing generally requires high purity and high brightness deposits of marble, chalk or limestone as the stone source. PCC usually uses limes made from lesser quality limestone deposits. GCC products have a wide span of particle size, with a d50 size ranging from sub micrometers to as large as several inches such as those used in landscaping. PCC products are typically limited to less than 10 µm (1,250 mesh). Each PCC product has a narrowly distributed size range. GCC and PCC products tend to have higher levels of whiteness com-pared with other traditional filler and extenders, such as kaolin and talc. Published statistics of GCC production volume often vary due to the exclusion of certain size range GCC products. According to Roskill’s latest estimate, world GCC capacity was believed to exceed 56 Mt (62 millionst) during 2004 for all grades.

Jan 1, 2005

By Wayne Green

The Regional Municipality of York, located north of the City of Toronto in Ontario, Canada, has experienced unprecedented growth during the past decade, with new home construction averaging 15,000 units per year. This rate of growth is planned to continue well into the future with a projected growth of more than 500,000 new residents by 2031, combined with a tar-get of more than 300,000 new jobs to provide a sustainable economic base for the region. It should be noted that York region has been designated as one of the key growth centers by the province of Ontario, aimed in part to meet the housing and employment needs of Canada?s growing population. York Region is a mix of urban and rural areas and is one of the most desirable areas to live in Southern Ontario. York region offers an attractive lifestyle, with its nine municipalities and the amenities created by the many rivers, streams and protected greenbelt areas that encompass more than 69 per cent of the region?s area.

Jan 1, 2010

By H. R. Hardy

Whether the mining engineer is concerned with stress problems in a mine at depth, the development of a new drill bit, or the efficiency of a comminution process, the mechanical properties of the rock with which he must work are of the utmost importance. One of the most popular topics in rock mechanics circles today is ?Is it possible to utilize directly parameters determined from laboratory tests on rock specimens in the analysis of mining engineering problems?? It is the author's opinion that laboratory and .field investigations have not yet reached the stage of development where this question can be answered with any degree of certainty. At present, great difficulties are involved in applying the results of laboratory tests to a mining engineering problem. However, this is due in part to the lack of detailed measurements of stress and deformation in the field and in part to the lack of development of satisfactory structural theories to correlate laboratory and field measurements. Furthermore, if mechanical properties measured in the laboratory are to be directly applied to the analysis of mining engineering problems, the critical mechanical properties must be identified, reliable test procedures must be developed and extensive test programs must be carried out.

Jan 1, 1964

By Mahmut Yavuz

to in Old Uighur Turkish as Tolay kopugu, in Ottoman Turkish as Derya kopugu, and in modern Turkish as Luletasi. Scientifically known as sepiolite, it is represented by the formula Si12Mg8O30(OH)4(H2O)4(8H2O). Sepiolite is a natural clay mineral composed of hydrous magnesium silicate, characterized by a structure of alternating blocks and tunnels that develop in the direction of the fiber. Each structural block contains two silica tetrahedral sheets surrounding a central layer of magnesium oxide- hydroxide. Sepiolite exists in two distinct forms in nature: alpha-sepiolite and beta-sepiolite. Alpha- sepiolite is amorphous, compact, and resembles pellets that look like sea froth, hence its Turkish name Luletasi. In contrast, beta-sepiolite appears as amorphous aggregates or small, flat, round particles. These two forms exhibit different physical properties. Meerschaum was also studied by Brauner and Preisinger in 1958, who agreed that it primarily consists of sepiolite (2MgO·3SiO2·nH2O). According to these researchers, water is present in its mineral, zeolitic, crystal, and structural forms. Meerschaum is commonly used for adsorbing various liquids, as an ion exchanger, and for dispersing and insulating paraffin in the chemical industry (Gokdemir and Dogan, 2011). Sepiolite deposits of the meerschaum type are primarily found in Turkey, Somalia, Tanzania, Kenya, and Mexico. Alongside high-quality, low-density, and highly porous meerschaum, Somalia also has sedimentary sepiolite formations. The total reserves of these deposits are estimated at around 50–100 million tons (Sariiz and Isik, 1995). Meerschaum, also known as “white gold” or “sepiolite,” is a unique mineral highly prized for its lightness, heat- resistant properties, and ability to be carved into intricate designs. Found predominantly in Eskisehir, Turkiye, meerschaum mining and processing have become significant contributors to the local economy and cultural heritage. This paper explores the history, economic importance, mining practices, and environmental impacts of meerschaum mining in Eskisehir and discusses the challenges and opportunities faced by the industry.

Feb 1, 2025

By Jerry T. Shelby

Surface and underground mining operations require equipment with high power output ratings. Haul trucks, loaders, dozers, and other equipment need increasing horse-power to meet production demands. To get more horsepower out of the engines driving the equipment, most manufacturers use turbocharging. Detroit Diesel puts the number at about 90% turbocharged, while Caterpillar estimates 75% to 80% of all its equipment is turbocharged. Turbocharging increases the power output and overall engine efficiency. But it presents some maintenance and operational problems that were not factors when only naturally aspirated engines (nonturbocharged) dominated the scene. A turbocharger is an exhaust-driven air compressor. Using the waste energy in the engine exhaust, a turbine wheel is driven. This wheel is connected by a common shaft to a compressor wheel. The shaft is supported by two plain bearings, or bushings. As the turbine wheel is rotated, the compressor wheel continually compresses the intake air to the cylinders. Compressing the intake air means that more air can be put into the cylinder to burn more fuel. The more fuel the engine can completely burn or combust, the more horsepower the engine can produce. Even though the turbocharger is a relatively simple device, it is a sensitive engine component. It requires special consideration at engine start-up and shutdown. Being freewheeling and exhaust driven, turbochargers can experience temperatures of 540°C 1000°F) and rotational speeds of more than 100,000 rpm. Due to those temperatures and speeds, lubrication is critical to the operation and life of a turbocharger. The turbo is located high on the engine, with the oil supply running through an external line from the sump. The recommended practice is to start the engine and allow it to idle for a few minutes before any revving or loading. This allows the oil to reach the turbo and properly lubricate the bearings before high rotational speeds are seen. Turbo oil supply lines can be as long as 1.5 m (5 ft). Depending on ambient temperatures and oil viscosity, it can take as long as 30 seconds for oil to reach the spinning turbo. However, as little as five seconds without oil can damage the turbo's bearings, reducing its life and overall efficiency. Lubrication problems seen at shut-down can also significantly affect turbo life and efficiency. Manufacturers recommend an idling period of five to seven minutes before engine shutdown. This allows the turbo to slow down and cool off somewhat to help prevent oil coking and bearing damage. When the engine stops, so does the oil supply. There is very little oil left on the bearing surfaces and in the turbo oil supply passages. The immediate heat transfer from the turbine wheel to shaft, bearings, and turbo body literally cooks what is left. This high heat without oil flow can cause bearing deformation by actually melting some of the bearing material. The rapid oil oxidation and coking will restrict oil passages, damage bearings and shaft. Besides heat soaking, there is another problem. If the turbo is spinning at high speeds when the engine is shutdown, the turbo must spin-down to a stop without oil flow. With the large size of turbos used on mining equipment, this spindown time without oil can be for as long as 10 to 20 seconds. Fortunately, lack of lubrication at start-up and shutdown and the subsequent bearing damage can be prevented by oil injection devices. These devices hold a reservoir of engine oil. The oil is injected to the turbocharger bearings immediately on start-up and for several minutes after shutdown. Oil injection devices are spring loaded, hydraulic accumulators. They are actuated at start-up by a solenoid wired to the starter motor. Engine oil pressure charges the accumulator during normal operation. Upon shut-down and loss of oil pressure, the device provides oil to the turbo for about two or three minutes. With an oil injection device, the engine can be started and immediately driven without fear of turbo damage. Also, an abrupt shutdown will not damage the turbocharger since the device will continue to lubricate for two or three minutes. A word of caution. Be sure the oil injection device provides positive oil displacement (pressurized oil flow). Do not use a gravity-flow device. Unless it is a true accumulator, the device could starve the turbo for oil on start-up, Ask for start-up and shut-down pressures and delivery times before considering installation. Keep the oil clean, and follow the manufacturer's recommended oil change intervals. These intervals are usually shorter than with naturally aspirated engines. Use oil with a CD rating designed for diesel applications. A multiviscosity oil is preferable. Use a synthetic engine oil, such as Mobil's Delvac 1, Gulf's Super Duty II, or Chevron's Sub-zero Fluid. Synthetics have much better flow properties at low temperatures. They also have greater oxidation stability (they can take the high heat of turbo-bearing lubrication. And they produce fewer deposits because they are more thermally stable. But synthetic oils do cost more - two or three times more. One additional point - maintain the air intake system. Since all mining is usually in a dusty environment, air filters should be changed regularly and intake systems should be checked for leaks. All intake air passes through the turbo. Any dirt or abrasives entering the turbo will damage the unit and shorten its life. While mining is a heavy duty business with severe operating conditions, you can get the life from your turbocharger that you expect by following a few simple steps: • equip the turbo with an oil-injection device to provide lubrication on start-up and shutdown; • change the oil and filters regularly; and • use the proper oil-synthetic, if possible.

Jan 3, 1987

By M. Slatter

The need for anti-corrosion coatings has existed for many years in the ground support industry, but the application requirements have made coating selection limited. Varying groundwater and chemical conditions continually challenge long term coating performance. Traditionally the industry coating preference has been hot-dip galvanizing due to its performance characteristics in highly corrosive environments and low cost nature. However, the galvanized coating has application limitations. This paper highlights some of these limitations and provides selection criteria for a new organic coating developed for one such difficult application, DSI?s Omega BoltPTM Pwhich is an expandable ground support. [ ]

Jan 1, 2009

By Thomas D. Kelly

In 1900, the average U.S. citizen’s average life span was 47 years. He traveled about 1,900 km (1,200miles) in a lifetime and resided in a home with an ice-box for food storage and oil or gas for lighting. He communicated by mail, telegraph and crude telephones with limited availability and range. By 2000, the average citizen’s life span was 77 years. He traveled an average of 19,000 km/a (12,000 miles/year) by automobile alone. He resided in a home with many electrical appliances, including refrigerators and electric lights. And he communicated almost instantaneously with any other part of the globe by several widely available means, including portable phones and e-mail.

Jan 1, 2002

By C. -G. Zhang

This paper presents the results of a study on cellular acclimation of Acidithiobacillus ferrooxidans to sulfur biooxidation in terms of cells growth and changes in surface properties and morphologies of both cells and sulfur particles. The results showed that A. ferrooxidans cells were grown faster and demonstrated higher concentration in the soluble thiosulfate substrate than in nonsoluble hydrophobic S0 substrate. The results showed that A. ferrooxidans cells acclimated to the sulfur biooxidation by actively expressing some extracellular polymers substance and maybe some outer membrane proteins that modified the surface properties of both sulfur particles and the cells themselves. In addition, the results showed that the A. ferrooxidans cells were able to dynamically adsorb to or desorb from the surface of sulfur particles. The cells aggregating onto the S0 surface enhanced the use of S0 substrate by the bacteria cells. This mode may be one of the most important characteristics for the better growth and propagation of the cells in solid sulfur-containing media.

Jan 1, 2009

By M. Moagabo

CO2 emissions from carbonate laden reclaimed mine spoil has been shown to pose a hazard to residents in homes built on or adjacent to such land. The objective of this project was to develop a soil CO2 flux survey protocol for assessing reclaimed mine land. The research involved CO2 chamber accumulation flux surveys; stable carbon isotope ratio analysis; statistical hypothesis testing to examine correlation between CO2 flux and soil temperature and moisture as well as spatial dependence; and geostatistics to map CO2 and delineate high flux zones. Soil temperature was observed to have a positive correlation with fluxes while soil moisture was observed to be negatively correlated. Spatial dependence of CO2 fluxes on reclaimed mine land was observed on one of the two study sites. The research suggests that macro-porosity and gas permeability may be important factors that explain CO2 migration in mine spoil. A flux survey protocol has been developed, based on these results, for reclaimed mine lands. The work demonstrates the capability of geostatistical methods to delineate high flux fields. Further research will be required to determine suitable thresholds for such analysis.

Jan 1, 2012

By S. Culp, P. Metcalfe

Web technologies and the Internet have revolutionized the computer industry. The Web browser technologies have also moved to portable devices such as Personal Digital Assistants (PDAs) and mobile phones. This paper looks at how to implement a Web Server solution and addresses some of the inherent advantages in the technology. It will also look at some examples of how plant productivity can be managed with a Web Server approach.

Jan 1, 2002

By Christian Neumann, Josef Arnold, Albin Reinhart

The Channel Tunnel Rail Link (CTRL) is the most significant railway infrastructure development project in the United Kingdom since the construction of the Channel Tunnel between France and England. The key element of this project is the 2-mile-long(3.2-km) North Downs Tunnel, which will be the largest and deepest twin-track railway tunnel ever constructed in the United Kingdom. This paper describes the contractual agreement, the design and construction (excavation and lining) of a twin-track rail tunnel with a 166-m 2 face excavated through chalk using the New Austrian Tunnelling Method (NATM). The importance of collaborating with a tunnel contractor/designer who not only is expert in the New Austrian Tunnelling Method, but who was also responsible for the design and installation of the primary lining, will be highlighted in this paper. This paper will also deal with the benefits of partnering in tunnel design and construction, as well as the resultant added values of mechanizing conventional tunnelling methods (Value Engineering).

Jan 1, 2001

By John Zeni

In Australia during the 1990s, Zeni Drilling took on several demanding shaft boring contracts. This paper describes the safety, operational, technical and environmental advantages derived through the implementation of mechanized boring methods for two of these projects. The paper first describes a 3-meter (10 ft) diameter access shaft blind bored from an underground location to 440 meters (1,444 ft) deep for a gold mine in Tasmania. The construction of a 5.8-meter (19 ft) diameter, 515-meter (1,690 ft)deep ventilation shaft for a longwall coal mine in New South Wales is also described.

Jan 1, 2001

By B. P. Faulkner, M. Weinecke

Svedala started a development program in 1997 to develop a process to convert waste tires into valuable commodities. A review of numerous approaches revealed short-comings in the various approaches either process, mechanical, combination of factors, or trying to emphasis the production of low value products. A market study revealed that a process that could produce a good grade of carbon black would be economically feasible. This paper discusses the laboratory and pilot plant development and commercial plant design.

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