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By F. J. Klingler, K. M. Swaffar, M. M. Rabbaig

The Detroit Water and Sewerage Department has undertaken a $1.2 billion effort to capture and treat combined sewage overflows from various outfalls along the Detroit and Rouge Rivers in Detroit, Michigan. This program is planned to include a 455,000 m3 (120 million gallon) storage and treatment tunnel which will capture overflows from 19 outfalls along the Rouge River. The tunnel is currently in the conceptual design phase, with the bid date planned for mid-year in 2001,and completion planned for August 2005. The total design and construction cost is currently estimated to be approximately $450 million. Current concepts are for the storage and transport tunnel will be 6.1 m (20feet) in finished diameter, with a total alignment length of approximately 12,200 m(40,000 feet). The main tunnel will extend through the Traverse and Antrim Shalerock formations, while approximately 5,500 m (18,000 feet) of various diameter connecting tunnel will extend through both rock and soft ground. The project will include a total of 10 drop shafts, 13 riser shafts, various connecting structures, and a 455,000 m3/day (20 mgd) pumping station. This paper will present a discussion of the design philosophy, subsurface conditions, the various planned components, and the expected design and construction considerations for the proposed Upper Rouge Combined Sewage Overflow Tunnel.

Jan 1, 1999

By F. Dudouit, M. M. Mohkam, F. Renault

The Pannerdensch Kanaal Tunnel is part of Holland’s Betuweroute high speed freight railway project linking Rotterdam to inland of Europe. It comprises of twin tunnels, 1620 m long each, with 8.6 m inner diameter. The Tunnel alignment is situated mainly in sandy formations and under high hydrostatique pressure. The over burden cover varies from relatively high to very low, sometimes much smaller than the diameter. One of the special features of the Pannerdensch Kanaal Tunnel is that, over some 250 m, the twin tunnels are to be bored in a back?lled sandpit. Some 490 000cubic meter of sand has been placed and compacted by vibro-?otation to refill the sandpit. The tunneling machine is a 9.8 m slurry shield manufactured by Herrenknecht. Tunnel lining is precast concrete consisting of seven plus one key universal segments. Other than the special feature of boring through re?lled sand, constraints such a slow overburden while crossing under Pannerdensch Kanaal and some lagoons, as well as high liquifaction potential of sandy formations, render this job very unique of the type. Fine studies were conducted in heading’s stability. And, confinement pressures were determined considering different risks of liquefaction and blowout problems. Both tubes have been successfully bored. Several sections have been monitored. The results are quite interesting and in accordance with contract technical conditions.

Jan 1, 2003

By E. H. Cho, P. K. Dai

An acid mine drainage sludge sample, containing 3.6% Mn, 0.18% Ni, 0.15% Co and 0.39% Zn, was obtained from central West Virginia. The sample was leached at room temperature with a pH 3 sulfuric acid solution. Air was then bubbled through the leach solution at pH 4.5 to precipitate the iron. The leach solution contained 258 ppm Zn, 105 ppm Ni, 90 ppm Co and 2050 ppm Mn. Three solvent extraction studies were performed to selectively extract these metal ions in a sequential operation with DEHPA. Cyanex 272 and Lix 84. The A/O ratio was one, and the extractants were diluted ten times with kerosene. A study of solvent extraction with DEHPA showed that Zn could be extracted without Ni or Co up to a pH of 2.75. A pH of 2.75 is considered to be the optimum pH to maximize the selective separation of Zn from Mn. The separation factor of Co over manganese suggests that the two metal ions should be extracted together by Cyanex 272. The separation factor of Co over Ni indicates that these two metal ions can be separated most effectively around pH 5.3. Also, Ni can be effectively extracted by Lix 84 above pH 5.5.

Jan 1, 1995

By Steven H. Brown

Ore bodies which were once uneconomical to mine by conventional methods such as tunneling or open pits, have become attractive due to the development of nonconventional techniques, involving considerably less capital expenditure. Technologies such as uranium solution mining or in-situ leaching, have enabled commercial scale mining and milling of relatively small ore pockets of lower grade, and may make a significant contribution to overall U.S. uranium supplies during the next 20 years. Commercial size solution mining production facilities have operated since late 1975. Solution mining involves the pumping of ground water, fortified with oxidizing and complexing agents into an ore body, leaching and solubilizing the uranium in-situ, and then pumping the solutions to the surface where they are fed to a processing plant. Processing involves ion exchange, precipitation, calcining, and packaging operations. This paper presents an overview of the solution mining process and the health physics monitoring programs developed over the last four years at several production facilities as a result of the radiological character of these processes. Although many radiological aspects of the process are similar to that of conventional mills, conventional-type tailings as such are not generated. Some special monitoring considerations are presented which are required due to the manner in which radon gas is evolved in the process and the unique aspects of controlling solution flow patterns underground. An overview of the major aspects of the health physics compliance and monitoring programs that have been developed are discussed.

Jan 1, 1981

By N. D. Jagger

In order to maximize the benefits obtained from flocculating agents when used as settling aids in high rate and conventional thickeners, it is often necessary to dilute the thickener feed prior to flocculant addition. In some cases, no flocculation at all is possible unless dilution water is used. The most common method of diluting thickener feed has been to recirculate some of the thickener overflow by means of a centrifugal pumping system. This represents a significant capital and operating cost. Supaflo Technologies of Australia has developed and patented an internal recirculation method known as Auto Dilution (or "Autodil") which is based on the principle that an hydraulic head differential exists between the inside and outside of the feedwell because of the higher S. G. of the pulp inside the feedwell, By installing non-return ports in the feedwell wall at the appropriate level, supernatant solution flows into the feedwell at a calculated rate and dilutes the feed without any need for external recirculation of overflow.

Jan 1, 1993

By Fernando Concha, Arturo Barrientos

The flow in a hydrocyclone is divided into a boundary layer around the walls, an exterior inviscid flow and an air core in the center of the equipment. The boundary layer flow over the lateral walls is associated with the short circuit of particles to the underflow, while the boundary layer over the top of the hydrocyclone and the outer part of the vortex finder tube is related to the short circuit of particles to the overflow. Classification takes place in the exterior flow. The model can be validated with pilot or industrial data and simulates the performance of hydrocyclones in a wide range of design and operating variables.

Jan 1, 1992

By Masaji Kato, Yuusaku Tominaga

To maintain good condition of ventilation for both safety and economy, many regulators are installed in a network. In case the open state of a regulator is different from the set point, identification of a broken regulator and a countermeasure to recover airflow distribution in a network must be initiated as soon as possible. An experienced mining engineer can sense a deviation from ordinary airflow quantity. In this paper, a new system to monitor all the regulators in a network is introduced. The basic concept of the system is utilization of both human sensing of airflow rate and computer simulation to understand the macroscopic characteristics of a ventilation network. A fuzzy pattern distinction method is used to process human determination of airflow rate that may be ambiguous. The applicability of the system is demonstrated using the ventilation network of the Horonai coal mine, Japan. In particular, it is shown that the system can identify the regulator to be repaired from information supplied by workers relating to air- flow in a few sensor branches.

Jan 1, 1997

By A. Subbotin

During developing the Ingulska mine at the Mi-churinske uranium deposit in the central part of Ukraine the radioactive rock dumps have been piled. A height of dumps reaches to 15-25m. They occupy a large territory and can be a source of covering with radioactive dust the area around the Ingulska mine. Uranium content exceeds 0,01% in all dump rocks samples while in the dust fraction samples it ranges from 0,01 to 0,06%. Uranium content in road dust at the dump?s foot reaches 0,137%. A new (for Ukraine) method of f-radiography of tree and bush leaves sampled at the territory about 100km2 has been used. It is based on fission of 235U nucleuses due to heat neutron influence in a nuclear reactor and on following study of the Lausan films with tracks drawn by the fractures of these nucleuses. Uranium content of the dif-fusion-disseminated dust type is (0.9-22.2)?10-6% while in the individual particles it can be considered much more because of burned holes in Lavsan above them. The dust content with uranium in Kirovograd reaches to 20-50 part/cm2 while near the dumps it ranges from 100 part/cm2 to 300 part/cm2 in the radius of 1,5-2km from the Ingulska mine.

Jan 1, 2005

In conjunction with steady increases in production levels, long-wall operators have applied greater quantities of ventilating air to control respirable dust and methane gas. As a result, air velocities greater than 7.6 m/s (1500 fpm) have been measured on longwall faces. Operators have expressed concern over the potential entrainment of respirable dust at these high-velocities, especially during shield advance as dust falls from the shield canopy directly into theair stream. Laboratory tests to simulate dust liberation by shield movement were conducted at the Pittsburgh Research Laboratory of NIOSH in a wind tunnel designed to study dust entrainment in high-velocity airstreams. Dust was introduced into the tunnel to determine dust concentration as it relates to entrainment, dilution, air velocity, and particle adhesion. Airborne dust samples were obtained by iso-kinetic sampling using BGI cyclones to quantify respirable dust concentration at the various air velocities. Laboratory tests were con-ducted at velocities ranging from 2.0 to 10.1 m/s (400 to 2000 fpm),and significant differences in airborne respirable dust levels were measured. This research is being conducted to provide fundamental information on the entrainment characteristics of respirable dust at high air velocities, which will subsequently lead to solutions for shield dust control. A discussion of the test procedures and results are presented.

Jan 1, 2004

By M. D. Loy

In addition to products available from private vendors, many useful programs are developed at universities - in fact, many of these programs led the way to commercial development. Other projects are assigned to consultants with backgrounds in system design and mining. Both types of development have led to programs that can be acquired for the cost of a tape or disk. This paper highlights several underground mining packages. These programs consist of: ? USBM model-developed by the United States Bureau of nines. ? PSU model-developed by Pennsylvania State University. ? VPI model-developed by Virginia Polytechnical Institute and State University. ? NUS model-developed by NUS Corp.

Jan 1, 1987

By C. C. Nolan

As the size of the mills get larger and the liners get heavier, a better means had to be found to handle liner replacement. McLellan Industries is famous for their innovative ideas and was called upon by an engineering company to develop a mill liner crane. The first crane was developed for Similkameen about 1969 to serve a 32' 0 x 14' Long SAG Mill. The next was Island Copper in Port Hardy, B.c., the same size as Similkameen in 1970. At that time, we took existing hydraulic cranes and modified them to meet the mill configuration. In 1973, we developed a completely new approach for the Southern Peru copper mine at Tacna, Peru for a Ball Mill, size 16'-6" 0 X 19' Long. Each installation required a design study to meet the change in mill size, trunnion size, elevation of floor to feed trunnion, area at the feed or discharge end of the mill. We have supplied self-propelled units as well as lift in. When there is no room at the feed end and if the mill has a trunnion overflow discharge, we have the mill supplier provide a structural frame to span the sump and move the mill liner handier into position with the use of the overhead crane or a mobile crane.

Jan 1, 1999

By C. C. Nolan

As the size of the mills get larger and the liners get heavier, abetter means had to be found to handle liner replacement. McLellan Industries is famous for their innovative ideas andwas called upon by an engineering company to develop a mill liner crane. The first crane was developed for Similkameen about 1969 to serve a 32' Ø X 14' Long SAG Mill. The next was Island Copper in Port Hardy, B.C., the same size as Similkameen in 1970. At that time, we took existing hydraulic cranes and modified them to meet the mill configuration. In 1973, we developed a completely new approach for the Southern Peru copper mine at Tacna, Peru for a Ball Mill, size 16'-6" Ø X 19' Long. Each installation required a design study to meet the change in mill size, trunnion size, elevation of floor to feed trunnion, area at the feed or discharge end of the mill. We have supplied self-propelled units as well as lift in. When there is no room at the feed end and if the mill has a trunnion overflow discharge, we have the mill supplier provide a structural frame to span the sump and move the mill liner handier into position with the use of the overhead crane or a mobile crane.

Jan 1, 1999

By Weston Bourret

The need for wartime supplies of uranium for the Manhattan Project prompted a 1944 study of uranium in South Africa. Uraninite had been reported by R.A. Cooper in 1923 in a Witwatersrand heavy- mineral concentrate, and the search for uranium, therefore, included the district's 30 operating mills. The method of investigation was simple: take bulk concentrate samples from the Wifley tables and determine their mineralogy. Samples were taken on a daily basis, although weekly composites also were taken of some mills. In 1944, most mills had simple gravity circuits and produced (I) a gravity concentrate, and (2) an all-slime [-75 pm (-200 mesh)] product. The tonnage throughput was known, and from that, head assays could be calculated. Concentrate samples were sent to the United States for chemical analyses. A Geiger counter set up in a Johannesburg hotel room provided preliminary data. The early data showed uraninite to be widespread. Microscopic, mineragraphic, and siezing tests were all under- taken in Johannesburg. Ultimately, tests led to a high grade (+90%) uraninite concentrate. Platinum and other heavies were the impurities. In seven months, the investigations had reached the stage where it was possible to forecast an annual production of 5.4 to 7.3 kt (6,000 to 8,000 st) of U3O8. The estimate is still realistic. Additional details are found in Bourret (1981).

Jan 1, 1991

By Pierre M. Matheron

TRANSMANCHE-LINK is responsible for designing, developing and implementing the project for a fixed link under the English Channel, comprising two running tunnels of diameter 7.6 metres and a service tunnel of diameter 4.8 metres. The three tunnels will all be 50 km long, with 37 km bored through chalk marl at a depth of 40 metres under the sea bed. The tunnels will be driven from both sides of the channel from intermediate addits above the coastline on either side with a 55 m access shaft at Sangatte in France and two "descenderies" or inclined tunnels addits and a shaft at Shakespeare Cliff on the English side. A total of eleven tunnel boring machines will drive the 150 km of tunnels. The major part of the tunnel linings will be built of precast reinforced concrete segments, and two plants have been specially built to produce the necessary 725,000 segments. Seven million cubic metres will be evacuated on wagons along the tunnels and then lifted by belt conveyor on the English side, and by hydraulic mucking from the bottom on the French side. Preliminary work started early in 1987 with manufacture of the first boring machines, construction of five precasting plants, boring of the Sangatte shaft in preparation of the Shakespeare Cliff entrances. The principal project dates are :

Jan 1, 1987

By Levent Ozdemir, Gerald Dollinger

An extensive series of linear and rotary cutting tests were run in soft and medium strength rocks at the Earth Mechanics Institute of the Colorado School of Mines to investigate the possibility of very high speed mechanical excavation for tunnel, raise, and shaft boring. The results of these tests demonstrate that cutter penetrations of 38.1 mm (1.5 inch) and cut spacings up to 228.6 mm (9 inch) are possible in such rock without exceeding the bearing capabilities of the cutters. It was also demonstrated in vertical boring tests that continuous excavation rates up to 38.1 m/hr (125 ft/hr) can be achieved with state-of-the-art technology provided sufficient thrust and torque is available. A predictor model for soft rocks was also developed using the test data. Analysis of this model shows that the errors between the predicted and observed cutter normal loads appear to be independent of cutter diameter, tip width, cut spacing, and depth of penetration. This suggests that the structure of the model is correct with respect to these variables. An analysis of the coefficients in the model was also made and a correlation found between the principal coefficient and Unconfined Compressive Strength. The second coefficient in the model was found to be similar in magnitude to rock properties such as Brazilian Tensile Strength, Shear Strength and Point Load Index.

Jan 1, 1989

By John S. Jones, Ralph E. Brown

INTRODUCTION For more than a century, artificial ground freezing has been used for groundwater control and structural support for excavations. Most of the early uses of the freezing method were for sinking deep access shafts for mines and tunnels (1,2,3,4). More recently, ground freezing has increasingly been used for construction of large diameter cofferdams and soft-ground and mixed-face tunnels (5). Although ground freezing has been used in the past-for tunnels, it was invariably used as a last resort measure, where more conventional measures could not be used. The more recent freezing applications, however, have become increasingly cost competitive with more conventional techniques, and are now being included as part of the design concept (6,7,8,9,10,11,12). The purpose of this paper is to describe some of the more recent applications of ground freezing for tunnel construction. The paper begins with a brief description of the most commonly used freezing system, the Poetsch process. Recent tunneling projects utilizing ground freezing for structural support are then discussed. DESCRIPTION OF THE FREEZING METHOD The most commonly used freezing method is the Poetsch process, which was originally developed by F. H. Poetsch in the late 1800's. The system consists of a brine coolant, typically calcium chloride and water. Freezepipes are placed into boreholes or are

Jan 1, 1979

By Thomas C. Anderson, Terry Weiss

The Mount Gunnison No. 1 Mine of the West Elk Coal Company (wholly owned subsidiary of ARCO Coal) had secured contracts to provide low sulfur, high Btu steam coal to various utility companies. This called for the development of the B-Seam at the Mount Gunnison Mine located some 400 feet below the operating F-Seam workings being mined with conventional room and pillar techniques. The B-Seam, to meet production goals, will be mined by a new 600-foot longwall machine making a 13-foot high cut. American Mine Services was awarded a competitively bid contract to drive two 2000-foot, 13-foot by 16-foot slopes at -15 percent, sink a 16-foot diameter ventilation shaft 400 feet between the F- and B-Seams, install a 60-inch conveyor in one of the slopes, remove 7000 feet of existing conveyor and rehabilitate 7000 feet in two entries to accommodate the placement of the longwall machinery. The slope portals were located 7000 feet in by the surface portal. Unique to the project was the placement of work shops and other infrastructure 7000 feet underground with an entry height of 6 feet. The $7 million contract was completed in less than one year using a mix of permissible (Schedule 31) and standard (Schedule 24) LHD equipment, all pneumatic jumbos and shaft sinking gear.

Jan 1, 1993

By Carlos Kovacs-Figueroa

Because of air pollution control regulations in the early 701s it became necessary to clean effluent gases from the Morenci Reduction Works Smelter. Feasibility studies indicated that this could be accomplished most efficiently by using the smelter gaseous effluent to feed a sulfuric acid plant. Complying with air pollution control regulations thus created the need to dispose of relatively large amounts of concentrated sulfuric acid. Typical Morenci ores contain substantial amounts of oxidized copper minerals which are not recoverable by flotation. In addition, there is low sulfide, high oxide material which can be leached, but is not suitable for flotation concentration. Early in 1971 sufficent data had been accumulated to show that a leaching plant for the Morenci tailings could use a large portion of the sulfuric acid produced by the Smelter. It was determined that for all practical purposes leaching of the available copper was complete in two hours or less. Capital expenditures could not be justified for more than two stages of counter current decantation for recovery of the leached copper, and the plant was designed with these criteria in mind.

Jan 1, 1976

By A. M. Gaudin

At the 1971 Annual Meeting we presented a paper on the results s obtained by wet magnetic separation on very fine, slightly magnetic material . Considerable interest was shown in a corollary subject, namely; on the type of magnetic con¬struction of the Magnetic Engineering Associates (MEA) high-intensity magnetic separator (HIMS). it is the purpose of this paper to describe the principles of this separator and to give answers to many of the questions directed at us both in session and privately since the March 1971 meeting of the AIME. It is well-known that passage of a direct electric current through a wire shaped in the form of a loop results in a magnetic field being created in the volume enclosed within the loop. The magnetic field is proportional to the amperes of electric current passing through the wire. If the wire is in the form of a solenoid consisting of 11 turns, the magnetic field is n times larger. Hence the expression ampere-turns commonly associated with magnetic separators. If a particle, free to rotate and of higher magnetic susceptibility than the medium, is placed in a magnetic field, it will orient itself within that field, and it will move within the field in such a way as to go into a more intense part of the field. The traction on the particle is proportional to its inherent magnetic property which depends on its magnetic susceptibility and its volume, to the mag¬nitude of the field at the spot where the particle is situated, and to the magnitude of the field gradient at that spot. Of the three factors that control traction on a particle in a magnetic field, the magnet designer can effectively control two, the magnetic field and the field gradient. In a wet magnetic separator such as the HIMS magnetic separator, there is another force exerting traction on the particle, and that is the force of the fluid (liquid) on the particle. It is, therefore, essential to examine the relationship of the fluid to the magnetic field. First, assume the water in which magnetic and non-magnetic particles are suspended to be stagnant. In the absence of magnetic field, the only forces acting on the particles are those due to gravitation on the particles and on the fluid displaced. This is the subject, so important in gravity concentration, discussed in elementary texts of mineral engineering'.

Jan 1, 1972

By E. P. Gustafson

Demand by precious metals explorationists for cost effective means to target subsurface geologic structures worthy of evaluation by means of drilling has led to the use of the predictor-correlator technique. To locate polarizable targets, the predictor-a localized inhomogeneity in electrical properties-is placed at various locations in the computer-simulated subsurface region, and correlated with the potential distribution observed in the field. The correlation coefficient obtained is assigned to the subsurface location. IP targets are extracted by calculating a second correlation section based on higher-frequency illumination and subtracting it from the first. The locations of correlation difference correspond to the locations of polarizable mineralization.

Jan 1, 1989