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By Zhenqi Cai, Mike Lichte, Kimberly Kennedy

The Ohio River Tunnel is the first of three combined sewer overflow tunnels to be constructed under Allegheny County Sanitary Authority's Clean Water Plan. The project consists of a total of approximately 5.5 miles of 18-ft and 14-ft finished diameter, segmentally lined deep rock tunnels and smaller diameter dewater and flow connector tunnels, as well as 8 deep flow drop and access shafts varying from 25-ft to 70-ft in finished diameter and 130-ft to 170-ft in depth. This paper describes the project components and the primary engineering challenges faced during design, including tunnel alignments and shaft site optimization with tight right-of-way constraints and multiple railroad and highway crossings. Assessment of tunneling methodology as well as tunnel and shaft designs and constructability included overcoming 5-bar hydrostatic pressure, abrasive bedrock, and the selection of the appropriate support of excavation systems in high-permeability alluvial soils adjacent to the Ohio River.

Jun 23, 2024

By Bruce F. Bohor

Silica sand has been mined in Illinois from the St. Peter Sandstone since the turn of the century, especially in the area around Ottawa on the Illinois River in the north-central part of the state. Production of this sand, consumed mainly by the glass and foundry industries but also sought after for many other uses, has grown with the economy, and last year's output in Illinois exceeded 4,000,000 tons. Such an important commodity was given the early attention of the Illinois State Geological Survey, and a very complete report was issued in 1928, authored by J. E. Lamar. The mining and processing of the sand has changed very little during the intervening 40 years, so that much of Lamar's data and descriptions are applicable today. More recently, the stratigraphy of the St. Peter Sandstone in north-central Illinois has become better known from the work of Willman and Payne (1942). The present authors have borrowed generously from Lamar's publication, and we wish to acknowledge the contribution of both of these studies to our work.

Jan 1, 1969

By J. S. Orphanos

The requirements for controlling air and stream pollution are a most timely subject for all concerned people. The coal industry has taken great measures to reduce both types of pollution. Through the use of more efficient scrubbing equipment on their thermal dryers, pollution has been considerably reduced. In many cases, the complete elimination of thermal drying by using centrifugal dryers to dewater fine coal products and meet customer specifications has completely eliminated air pollution from this source. To help eliminate stream pollution and the hazards created by tailing ponds, the coal industry is using centrifugal dewatering equipment. Use of centrifugals to dewater fine refuse for disposal would eliminate refuse ponds or extend their life. In doing this effectively and economically, preparation plants have the option of recycling the clarified water to close the water circuit or of discharging the water into receiving streams with the assurance that it contains an acceptable amount of refuse solids.

Jan 1, 1974

By V. D. Hanson

When maintenance of a plant or operation is under discussion immediately three "M's", all in short supply, are brought to mind - money, men and markets. This paper will present what currently is being done at our plants and its effect on the 3 "M's". Examination of coal realization figures (F.O.B. Mine) from 1945 to the present reveals the fact that open and free competition can and will meet market conditions. The industry, without benefit of advantages afforded tax and transportation wise to oil and gas, remains the backbone of the energy market of United States. Figure No. 1 shows the realization figures from 1945 through 1962 compared to the hourly earnings. Note that through 1945 to 1948 F.O.B. prices increased $1.93 per ton while hourly earnings increased $.66 per hour. Since 1948 (with the ex¬ception of 1957) F.O.B. prices have declined $.45/ton, while hourly earnings have increased $1.23 per hour. Basically the maintenance men possibly represent the highest increment rate in the overall hourly earning.

Jan 1, 1963

By P. Tsakiris

The increasing social interest for the environmental issues, forces the authorities to enact more rigorous regulations. The mining industry is one of the sectors that concentrate vigorous remonstrance. It is an absolutely justified reaction, as a result of the numerous contaminated and polluted sites that have been inherited by previous operations and they remain unremedied. The lack of a consolidated global legislation, transfers the burden of decisions to the national level. This paper consists of two parts. At the first part, it discusses the critical role of the state to form an effective environmental policy, feasible for the context of the national economy. Afterwards it analyses two of the main points, which must be considered by the regulator for the excavation activity, the abandoned sites and the duration of the mining investment. The aims are to defuse, in the short-term, the public pressure, protecting the economic growth and, at the same time, to form a basic structure for the development of the corporate social responsibility. The second part presents an alternative financial instrument for the Greek regulatory framework, conformed to the characteristics of the Greek Economy, and analyses the expected benefits both for the business and the social welfare.

Jan 1, 2002

By L. R. Berry

The successful selection of a slurry pump depends on the accuracy and completeness of the information provided for the application. Inaccurate or incomplete information can result in incorrect pump selection and / or operational problems. Some information is more critical to the selection process than other information. A full description of the slurry (liquid -solid mixture) including the particle size distribution and maximum concentration, the flow, head and NPSH requirements are most important for successful slurry pump selection and operation. Common problems resulting from improper slurry pump selection will be discussed to illustrate the need for correct selection requirements.

Jan 1, 1996

By Wolfgang H. Roth, Stephen J. Navin, Samuel K. Louis, Anthony F. Stirbys

This paper presents a case history of the design and construction of the access shaft and cross adit utilized to gain access to the Los Angeles Metro Rail tunnel alignment, at the A146 Contract site. The access shaft, a 14 m (45 ft) inside diameter structure, was constructed using ring beams and lagging with concrete backfill to a depth of 18.59 m (61 ft). The cross adit was hand excavated in sequential benches using liner plate, arch ring beams, and posts for support. The sequence of excavation and support placement are discussed. Soil conditions encountered at the project site are discussed together with the development of the design criteria. Instrumentation data collected during the excavation are also presented.

Jan 1, 1989

By Felipe Calizaya, Sekhar Bhattacharyya

Mechanized underground mines suffer from noise overexposure. Noise levels are often above the Permissible Exposure Limit (PEL) where underground fans are used. Sound levels in active workings can reach up to 121 A-weighted decibels (dB(A)), especially when fans are not equipped with silencers. Use of silencers seldom ensures PEL. Overexposure of noise induces permanent hearing loss among mine workers. A NIOSH-funded research project and field studies at six coal and non-coal mines revalidated the findings. The University of Utah undertook laboratory studies to reduce fan noise at the source. A new silencer prototype with varying noise dampening material was designed and tested. The silencer and associated extension can be repacked with different dampening materials. The silencer and the extension were used in various configurations. Attempts were also made to simulate field conditions. The tests demonstrated a maximum sound level attenuation of about 14 dB(A) at the fan discharge. A properly designed silencer offers lesser resistance and thereby better fan performance and lower energy cost. The re-packable silencer is more likely to be maintained properly. Lowering of noise level happens in audible frequencies (4000 to 8000 Hz) which are important in A-weighting.

By Diana Diaz, Rakshith Shetty, Vitaly Proschenko, Mike Mooney

Cohesive clay soil poses a significant risk to earth pressure balance tunnel boring machines (EPBM) due to unstable face pressure, clogging potential, high cutterhead torque, poor muck flow, low advance rate, etc. This paper details the performance measures desired when EPBM tunneling in clay soil, and the scientifically-supported conditioning methods to transform in-situ clay to a muck with such characteristics, giving particular attention to ground conditions. The paper then examines TBM data from multiple clay soil projects in the context of these performance measures to demonstrate the influence of cohesive soil conditioning on EPBM performance.

Jun 13, 2023

By T. Eggenberg

Mechanization and automation of logistic equipment has become one of the main key factors in raising productivity and competitiveness especially for complex and larger mining or tunneling projects. The Lake Mead Intake Tunnel #3 shaft mucking installation is a good example to demonstrate the potential that is found in an overall optimized logistic. It starts with the planning and results in using customized installations which fulfill the specifically defined requirements for the project. Rowa developed a solution and supplied a shaft mucking system using a discontinuous double drum hoisting concept with shaft buckets, loading, and unloading devices. With this fully automated system a continuous muck flow of 437t/h can be achieved.

Jan 1, 2010

By G. J. Allen

Kennecott Copper Corporation's Nevada Mines Division initiated a program to stabilize the inactive portions of the tailings disposal area and perimeter dikes in 1946. To date, approximately 1,000 acres have been stabilized with vegetation and ground cover.

Jan 1, 1978

By E. K. Albert

Title IV of the 1977 Surface Mining Control and Reclamation Act (SMCRA) provides for an abandoned mine reclamation fund. This fund, taken from fees collected from operating coal mines, provides capital for the reclamation process. The Act directs the Office of Surface Mining (OSM) to collect the fees based on coal production. Monies from the abandoned mine lands (AML) fund are distributed through two programs. The first provides OSM with capital to use in emergency situations resulting from abandoned mine sites and reclaiming high priority sites in states without established AML programs. The second distributes the money through a state's AML program in the form of grants. To provide for a flexible and customized selection procedure for AML projects, a management information system (MIS) that combines scientific selection procedures is being developed. This system employs objective and subjective methods developed in systems research in recent years. The MIS component is an essential part of any selection process involving large numbers of potential projects. It must contain all the necessary project parameters that can be applied to the selection of projects whether or not they are to be used in the immediate selection criteria. In addition, variable selection criteria will allow ‘what if’ types of inquiries for comparison of differing selections and benefits.

Jan 1, 1990

By T. R. Hughes

How do you fit a processing plant underground with minimal change to mine infrastructure and yet maintain economic recovery, operability and maintainability? By combining fine crushing, continuous-gravity recovery and flotation. A modular, transportable processing plant has been designed that is capable of being installed in underground drives/drifts or on the surface. The Python processing plants have been designed to treat 20 or 50 tons per hour of ore to a particle size of approximately 500 µm and recover gold and sulfides into the concentrate. The plant is only three meters wide (including bolt-on platforms) and can be installed on a 1:50 slope, making for very simple installation. Test work carried out by Gekko Systems Pty. Ltd. has indicated that up to 50% of ores tested to date would achieve gold recovery rates of over 90% using this method. The projected benefits of this strategy are numerous and include low overall capital and operating cost, significantly less power consumption compared with traditional milling circuits and low environmental footprint.

Jan 1, 2010

By B. W. Firth

Increasing depth in vertical mine shafts penalises conventional hoists in at least four distinct ways: rope weight becomes limiting; travel time increases; the obstruction of ventilation becomes more serious; and with friction drives, rope wear due to torque is aggravated. Travel speed is limited by instability of poorly sprung conveyances on inaccurately aligned flexible rails, and also by the cost of installed power to meet an inherently peaky demand. These problems call for a review of existing designs, firstly in respect of the furniture (Buntons and guides) obstructing the air flow, and secondly in regard to the hoist running in the shaft.

Jan 1, 1969

By James J. Fallon

I'm glad this meeting is being held in New York. First, because the city is close to my home in New Jersey, only 35 minutes from Times Square ..... if I were to come to Times Square between two and three in the morning. Otherwise it takes two hours. But even more important is the fact that all of you good people from around the country and around the world will enjoy the unique experience of that warm friendly atmosphere in the greater metropolitan area, something that you won't see any place else on the face of the earth. Seriously, the greater metropolitan area has been a large part of my industrial, cultural and spiritual experience. There are many aspects of it which I find disagreeable but on net I would rather live in this area, at least for the time being, than any other area of the United States. As a consultant I find contact with financial institutions, corporate headquarters, information sources and a great many production and research facilities a valuable asset to my activity.

Jan 1, 1985

By A. A. Wallach

During the early design stages of the San Manuel Concentrator, numerous questions were raised concerning the required slope for tailings pipelines. The tailings disposal area which had been selected was so situated, that an average down-slope of 5% existed. A gravity tailings disposal system was to be designed and it was necessary to determine the optimum pipeline slope for design purposes. This information was also necessary to determine the life of the available disposal areas before tailings pumping would be required. At approximately the same time as this problem arose, it was reported that a concentrator in the southwest was having considerable operational difficulties due to periodic plugging of tailings lines. These factors combined made it seem desirable to conduct some sort of test work which might give information concerning the flow characteristics of the tailings to be produced, from the San Manuel Concentrator. It was felt that the maximum information could be obtained if a tailings line could be erected which would allow for varying slopes, varying heads and accurate measurement of pulp velocity. A five-foot Denver Agitator was installed on a bank overlooking a cut for a rail- road track. Approximately 160 feet for new &-inch pipeline with victaulic connections was installed on low trestles along the track, with provisions made for varying the slope of the line by use of accurately constructed sets of shims, A valve discharge was installed on the tank so agitated pulp could be run into a standpipe at controlled volumes. This standpipe was 10 inches in diameter and approximately 5 feet high. A 4-inch nipple welded into the side of the standpipe approximately one inch from the bottom was connected to the 4-inch pipeline. At the discharge end of the 4-inch pipeline a launder arrangement was so constructed that the entire discharge could run into a pump sump or into 50-gallon measuring vessels. In normal operation the flow was from the agitator to the standpipe through the pipeline into the pump sump and from there pumped back to the agitator tank.

Jan 1, 1958

By J. C. Yingling, J. Sottile

This paper addresses detailed models of the temporal pattern of material flows produced by longwall mining units and procedures for inferring the parameters of these models from field data. First, a model is established that predicts material flows referred to shearer position and cutting element. This model is comprised of trend and fluctuation components. The trend component, which is invariant between repetitions of the cut cycle, accounts for deterministic effects on the flow pattern, such as web depth variation as a function of the cutting operation, systematic tendencies for seam height and cutting speed variations along the face, changes in the relative velocity between the shearer and face conveyor, etc. The fluctuation component models random effects on material flow and employs time series approaches. Subsequently, a method is given for converting the positionally-referenced flows to temporally-referenced flows. The model serves as a basis for generating detailed, accurate computer simulations of material flows from longwall units. As such, it provides a more rigorous foundation for analysis of cutting procedures and outby materials handling systems in longwall mines.

Jan 1, 1994

By C. G. Anderson

Historically, the treatment of orebodies for recovery of valuable constituents presents many processing challenges. In a time of heightened environmental awareness, the constraints placed on processing complex orebodies are becoming more and more pronounced. As such, established technologies are limited in their ability to fill the needs of these emerging sources of raw materials. A prime example of this is in processing PGMs from primary sources. Normally, this type of material is found in a nickel-copper-iron sulfide matrix. Typically, these materials are processed by established pyrometallurgical means. However, other options should be considered. Hydrometallurgical processes are available which offer advantages over pyrometallurgical methods. One of these is the nitrogen species catalyzed sulfuric acid pressure leach used industrially by Sunshine Mining and Refining Company. In 1990, laboratory work was undertaken in cooperation with Stillwater Mining Company to test PGM matte materials from the Columbus, Montana smelter. The initial results were very positive, and they led to a design to recover PGMs in a high grade residue and to recover nickel and copper as valuable products. Handling the iron and other wastes in an environmentally safe manner was also successfully investigated.

Jan 1, 1995

By R. M. Geisenheyner

We are in the midst of a transportation revolution. From the Wright Brothers to the SST. From the Toonerville Trolly to the 120-mile-an-hour Northeast Corridor train. From Christopher Columbus to Neil Armstrong. There is another side to this revolution and it is going on every day at our mines and factories. We call it bulk distribution. Perhaps ordinary sounding, but every bit as exciting as those other transportation innovations. Basically, we have gone from bag to bulk, and in the process reached that Last Frontier in manufacturing cost savings. By revitalization of our distribution system, we have made it possible for our mines and factories to realize fully the vast economies of spage-age manufacturing techniques and accomplishments. The pacesetters in this distribution revolution have been you gentlemen, the producers and shippers of dry mineral products. In this area bulk distribution grew up. And here most of the current innovations are being introduced. Management of your industry was early to realize the economic advantages of bulk distribution. Distribution costs of your products comprises a sizeable, portion of the selling price and management is sensitive of any developments which may even slightly reduce the cost of transportation, marketing or the exploration of new frontiers.

Jan 1, 1969

By Oscar H. Lentz

During 1960, the controversy over percentage depletion reached the level of debate between presidential candidates. Nixon took the position that he would not tamper with the status quo in this matter. Kennedy took the position that he was willing to take a fresh look at the issues involved. Kennedy's position appears to have been based upon two premises: (1) new sources of federal revenue may be needed; and (2) current depletion rates, even if sound in principle, may be too high and, therefore, inequitable. The latter premise constitutes the basis for the claims that depletion allowances are simply "loopholes" of tax avoidance. Very probably the controversy over percentage depletion will remain in the political limelight during most of the coming decade. It is quite possible that the current depletion rates, at least those for oil and gas, will be reduced during this period. The aim of this paper is to isolate the complex causes of this mounting opposition to percentage depletion.

Jan 1, 1961