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By J. James Eidel

Geological interpretations generally require projections from direct observations at the earth's surface. Crustal projections include mineral deposits as well as the geochemistry of the crust and its fluids, structure and tectonics. Drilling offers opportunities for verification of the required projections, and is thus a required step in furthering crustal understanding. Like any new science, the direct observations that drilling provides commonly generate major surprises and stimulate totally new ideas. Drilling is costly. There are many critically important scientific problems with societal and potential economic benefits in mineral deposits which have not been drilled because the holes are difficult to justify as economically sound risks for private capital. Such holes, however, are highly justifiable research goals for government because of the significant new opportunity for ore deposit insight and exploration that they afford. The earth science community is prepared with excellent drilling projects for research in mineral deposits.

Jan 1, 1985

Joy Mining Machinery has developed a new generation of ultra-heavy shields for Anglo Coal Australia?s Moranbah North Mine in the Bowen Basin region of Queensland. These are the largest two-leg longwall shields yet produced by Joy. The longwall at Moranbah North posed a number of challenges, among them a thick, inclined, sometimes undulating seam with increasing depths. The result of this was the need for larger, heavier, more powerful roof supports. Knowing that future longwalls would be going deeper, mine management determined that shield yield ratings of at least 1,750 t (1,930 st) was what would be required.

Jan 1, 2011

By Stanley V. Lachmansingh

Bauxite can be regarded as a mixture of hydrated aluminium oxides the predominant constituent - and oxides of iron and titanium, silica and silicates. Heterogeneous and non-crystaline, most bauxites vary in average composition from one deposit to another both in terns of impurities as well as the proportion of Gibbsita and the Monohydrates Diaspore and Boehmite. Iron levels (as Fe2O3) can vary from less than 1% to as high as 30% with the alumina content ranging from 40 to 6o%,. Gore than 90% of all bauxite mined in Guyana is used as feed for the - production of refractory grade calcined bauxite. There are -however, several speciality grades used in various industrial applications and these are characterised by the quality of the bauxite in particular ;,with regards to iron and silica levels which generally have to be low. The main speciality grades are designated Refractory, Abrasive and Chemical. Bauxitte is also used in the production of nigh alumina cements,, activated bauxite end in the manufacture of electrical insulators.

Jan 1, 1977

By Francesco Chiappalone, Marco Invernizzi, Franco Gasperin, Brad Yoder, Fabrizio Fara

The Ship Canal Water Quality Project includes a 2.7-mile, 18-ft and 10-in internal-diameter tunnel that extends from Ballard to Wallingford, two popular neighborhoods in the West of Seattle. During the TBM Main drive a 12' × 12' boulder with variable strength up to 47,000psi was encountered resulting on signicant damages to the Cutter ead. The rst part of this paper describes the design and construction of an underground recess in front of the TBM to create a safe working environment for the TBM repairs. The second part describes an injection campaign performed to seal an unforeseen water inow appeared during the excavation of the 11 Avenue Diversion Structure.

Jun 23, 2024

By H. M. Ray

The discovery of the New Lead Belt in the mid-'50s began a search for mill design criteria that is continuously updated. The opportunity to design, construct, and operate four new mills in the span of 20 years provided fertile areas for new concepts. The central theme for design parameters encompassed simplicity, functional, and economic consideration. Ore characteristics for each plant remained relatively constant, providing stable criteria for grinding circuits. Bond index nominally 10-12. Flotation circuit parameters were based upon power application with 10-20% excess capacity built-in to protect recovery. Newer equipment exhibits greater power application efficiency lowering horsepower requirements per ton. Instrumentation was installed to stabilize circuits, protect equipment, and improve products. With ever increasing requirements of higher quality products, environmental considerations, and operating cost pressures, the upgrading of operating procedures is in a constant state of flux. Installation of more efficient equipment, chemical processing, or any other technique would be considered as feasible. Current practice is for St. Joe to design and engineer in-house its own plant design. The exception being detailing of structural steel. It is felt that familiarity with past design criteria serves as a valuable foundation to incorporate changes. Also, direct contact with operator provides specific data, and feedback for constructive criticism that is utilized for defining and correcting problems. The results are in reality an operator's plant with the benefit of advancing technology that meets the demands for improved products without sacrificing the economies of throughput or recovery.

Jan 1, 1977

By Isabel Barton

This article describes and analyzes the history of research into the origins of the uranium-vanadium(-radium) deposits of the Paradox Basin. For several decades after their discovery in 1881, research was desultory and almost entirely descriptive, fluctuating with demand for vanadium and radium. Systematic geologic descriptions, accumulated between 1910 and 1950, supported rapid progress during a government-backed surge of research in the 1950s, when uranium was the chief commodity of interest. Most of the major theoretical innovations date from this decade, including the use of concepts from solution chemistry to identify the conditions and constrain the processes of deposit formation and alteration. Research from this time was highly influential in geology at large, providing the model for sandstone-hosted uranium deposits worldwide and numerous new minerals and mineral structures. After about 1960, mine production remained high but research dwindled, and most new advances were to the details of the hydrothermal model of ore formation rather than its core concepts. By the end of the 1960s, the deposits were understood to have formed at the mixing interface of an oxidized, metal-bearing water with a reducing fluid of debated origin. Research was desultory over the ensuing decades; the source of the metals and the nature of the chemicals constituting the trap were not clearly established. They remain questions today, as do factors like the relationship between ore mineralization and the geologic history of the basin. (More in the full paper.)

Jan 1, 2025

By S. Chander

The fundamentals of flotation are reviewed with an objective to understand the limitations in predicting the performance of a sulfide mineral flotation system and in its scale-up from laboratory studies to plant practice. The difficulties can often be traced back to complex interactions between chemical and physical parameters and nonequilibrium effects. The physical and chemical changes that occur during the long sojourn of sulfide minerals that begins with mining, continues through crushing and grinding, and ends when they emerge from the flotation cell as a concentrate, are reviewed. The benefits of new techniques that have become available in recent years to identify and estimate the amount of surface species are discussed.

Jan 1, 1999

By I. Weir-Jones

[Currently the cost of carrying out 'in situ' geotechnical investigation programmes or installing and operating monitoring systems at construction or mining sites is rising var." rapidly. This is primarily because of our ever increasing labour rates. As a result of this problem efforts are no,, being made develop techniques for the economical; collection of large quantities of geotechnical data relating, to such problems as done stability evaluation, the behaviour of underground openings, or 'in situ' testing procedures. The efforts to reduce the labour content. are particularly apparent in those procedures which have traditionally been manpower intensive e.g. 'in situ' permeability testing where an entire drilling crew and their associated eguipment have been on standby while testis has been carried out; or data collection in underground construction operations where much tine is typically wasted obtaining or maintaining access to instrument sites. In an attempt to illustrate one specialist consulting company's approach to the problem of reducing investigation costs, this rarer examines four recent developments in the field of geotechnical investigation and monitoring which have come about during the last two Years as a result of cur research and development programme. Although these techniques and devices have been developed for specific projects, they all have broad applications in the geotechnical field and they are indicative of the direction in which this company feels developments will take place.]

Jan 1, 1975

By Paul G. Schmidt

The Crandon massive sulfide deposit Forest County, Wisconsin, was discovered by Exxon Minerals Company, U.S.A., in July 1975. Announced estimated in-place reserves are 62 M metric tons (70 million short tons), grading about 5% zinc and 1% copper. The reserves are evenly divided between massive sulfide are and stringer sulfide ore. The sulfide body is associated with Precambrian felsic pyroclastic rocks, and it is overlain by intermediate volcanic rocks and their derived sedimentary rocks. These rocks were subjected to greenschist facies metamorphism and were tilted to a near-vertical attitude. Geologic observations indicate a submarine-volcanic-exhalative origin for this deposit.

Jan 1, 1978

By M. L. Rizzone

Since time immemorial, Mother Nature has been transporting slurries with both air and water serving as the carrier medium. Consider for example the formation of the continental shelves off our coast lines which are being formed by rivers emptying erroded land surface and depositing it into bays and gulfs. As the erosion processes take place, the fines are suspended in water which flows in streams and rivers and deposits where the velocity of the flow reduces sufficiently to allow the fines to settle out. The same process in some crude form is provided when one hoses his driveway or patio and moves dirt so as to provide a cleaning action. These examples illustrate rather crudely how the formation of slurries allows for the transport of solids. In recent years, this mechanism has become fairly well understood and slurry pipelining of many materials is now a vivid reality. The movement of liquids in pipelines necessarily occasions the use of pumps for the purpose. Those of us who have had some rub with the petroleum industry are familiar with the transport of solids through mud pumps and cementing and fracturing pumps where the movement of slurries is an everyday matter. In the drilling of an oil well the circulating fluid utilized to remove chips which are cut by a drill bit from holes drilled deep in the earth is called drilling mud. This substance contrary to what the name might imply is usually a fairly sophisticated material designed to develop certain characteristics which are desirable in the drilling process. The particles which have been cut by the drill bit are suspended in the moving column of fluid and brought to the surface and deposited. The separation of the cuttings from the drilling fluids is accomplished by the use of shaker screens and settling pits. However, it is impractical to remove the fines completely from the drilling fluid and as a result they are pumped through the mud pumps back into the circulatory stream.

Jan 1, 1969

By J. Lizak

Calcium carbonate is one of the highest volume industrial mineral products in North America. It is used in filler and extender applications, roofing products, floor tile, glass manufacture, etc. Calcium carbonate has over a dozen major filler and extender applications plus a host of minor uses. North American consumption of calcium carbonate fillers and extenders in 1991 is estimated at over 5,000,000 tons valued in excess of $400,000,000. There were five major suppliers of calcium carbonate fillers in the Middle Atlantic region in 1988 :?Bestone, Genstar, National Gypsum, Thomasville Stone and Lime, and White Pigment. With the exception of Genstar's Maryland operation, all of these operations are within a few miles of York, Pennsylvania. The Millington Group (TMG) purchased the assets of Bestone Corporation in February of 1989. TMG then seized the opportunity to strengthen its business position by acquiring National Gypsum's and White Pigment's Pennsylvania filler businesses in December, 1989 and July, 1990, respectively. By July of 1990 TMG's filler business acquisitions included six quarries and one underground mine, totaling over 1,200 acres and three processing facilities. The assets were restructured into two new companies - Delta Carbonate, Inc. and Penroc, Inc. (hereafter collectively referred to as Delta). Delta identified the assets of the three predecessor companies as undervalued from the outset. The initial phase of Delta's turnaround strategy was to reassess the combined mineral. mining, processing, transportation and marketing assets. The second phase was to effectively integrate these resources in order to exploit their inherent synergy.

Jan 1, 1992

By A. B. Seal, C. J. Bise

Excessive noise has long been a hazard in the coal-mining industry. Studies conducted during the mid-1970s and mid-1990s consistently show that hearing loss within the mining industry persists, in spite of regulatory requirements and sampling technology advances. When the U.S. Mine Safety and Health Administration's new health standards to protect miners from hearing loss took effect in September 2000, the potential developed to reevaluate sampling approaches with regard to noise-source hazards, such as task-based methods. This paper describes results from a Pennsylvania State University research project now being conducted at an underground coal mine. Each occupation was reviewed, and a list of tasks or processes performed by each was generated. Traditional personal noise dosimetry, static sound pressure levels and equipment sound mappings have been performed. Job tasks indicating the greatest levels of daily noise exposure and contributions to noise dose have been identified and will be discussed.

Jan 1, 2003

By D. L. Misterek, E. J. Slebir, G. W. Ring, M. A. Laird

INTRODUCTION In 1973, the Federal Highway Administration (FHWA) initiated a 10-year program of research on tunneling technology for future highways as a part of a larger Department of Transportation effort on tunnels. The objectives of the FHWA program are to: improve tunnel design technology, reduce costs, minimize adverse environmental impact due to construction, increase the rate of construction, and assure the maintenance of a safe and attractive tunnel environment. The program is divided into four research tasks designed to solve tunneling problems identified by the engineering and field offices of the FHWA. These tasks are as follows: 1. Cut-and-Cover Tunneling 2. Site Investigations 3. Ground Movements - Prediction and Control 4. Highway Environmental Criteria for Tunnels In order to provide input into Tasks 2 and 3, the FHWA is sponsoring an investigation and testing program by the U.S. Bureau of Reclamation to instrument and monitor two sites in the second bore of the Eisenhower Memorial Tunnel located on Interstate Highway 70 at Loveland Pass approximately 97 km (60 miles) west of Denver, Colorado. The tunnel will be approximately 14.0 m (46 ft) in diameter when excavated. The study is designed to generate data on: (1) changes in the state of stress, and movements during and after tunneling, (2) tunnel lining design requirements, (3) developing a

Jan 1, 1976

By James P. Dorian, James M. Otto

The value of exported nonenergy minerals from the less-developed countries has increased substantially between 1970 and 1985, but their market share relative to world exports has remained stagnant. Of the top twenty minerals exporters, only four are developing countries. Production capacity in the developing countries is shown to be less sensitive to demand downturns than capacity in the developed countries. Two approaches to the management of cyclical minerals demand are given using examples from India and Papua New Guinea. The authors conclude that pro¬tective policies implemented by developing nations have, barring a few exceptions, relatively little impact on the chronic nonfuel minerals oversupply problem.

Jan 1, 1989

By Alejandro Sanz Garrote, Juergen Laubbichler, Fernando Triana Gracian, Paz Navarro Gancedo-Rodriguez, Andreas Feiersinger

The Combined Sewage Storage Tunnel (CSST) is part of the Ottawa River Action Plan and will greatly reduce the frequency of sewage overflows into the Ottawa River during storms. The project consists of the design and construction of two TBM tunnels running EastWest (EWT) and NorthSouth (NST) along 6.2 km in total, and multiple shafts and support buildings. Contractor Dragados Tomlinson JV (DTJV) was awarded the 169 million CAD construction contract in 2016 and the CSST will be in operation in 2020. Dr. Sauer & Partners (DSP), supported by Intecsa-Inarsa, was responsible for the detailed design of the precast concrete tunnel lining as well as the geotechnical risk management program. This paper addresses TBM selection, critical tunnel sections, geotechnical risk management and rock mass grouting as a geotechnical risk mitigation measure. Successful collaboration of Owner, Owner’s Engineer, Contractor and Contractor’s Engineer led to a safe and cost-effective design and construction

Jun 13, 2021

By Joel Nonnweiler, Galen Samuelson Nagle

The Sacramento Regional County Sanitation District (SRCSD) has undertaken an interceptor expansion program to meet future wastewater needs associated with projected growth over the next 20 years. The Lower Northwest Interceptor (LNWI) will include over 17 miles (27 kilometers) of pipeline including 14 miles (23 kilometers) of dual force main ranging in size from 54- to 60-inch (137- to 152-centimeter) diameter and 3 miles (5 kilometers) of 120-inch (305-centimeter) diameter gravity pipeline. The estimated capital cost for the program is $331 million, with approximately $236 million in construction cost (as of November 2002). The project includes 4,700 feet (1,433meters) of tunnel including 2 crossings of the Sacramento River and one crossing of the Barge Canal, and 11 other smaller tunnel crossings beneath various creeks, sloughs, highways, and railroads. Preliminary design of the tunnels for the LNWI are discussed in this paper. The overall purpose of the preliminary design was to sufficiently define the project to allow planning level cost and schedule estimates to be performed. There have been changes to the project during final design including pipe sizes and configurations, tunnel and pipeline lengths and anticipated flows. This paper addresses only the preliminary design of the LNWI tunnels. Final design issues and changes made since completion of preliminary design are not addressed in this paper.

Jan 1, 2003

Improvements in cost efficiency, noise control, environmental design and ergonomics ? the mining and construction industries are facing demands on many fronts. The international manufacturers of construction machinery are responding to these challenges, and they will be presenting their innovations in all these fields at bauma 2013. bauma, the international trade fair for mining and construction machinery, mining vehicles, and building material machines, takes place from April 15 to 21, 2013 at the Messe Munchen exhibition center in Munich, Germany. The last bauma, in 2010, attracted 3,256 exhibitors from 53 countries, and more than 420,000 visitors from more than 200 nations. Covering a total of 555,000 m2 (5.97 million sq ft) of exhibition space, bauma is one of the largest trade shows in the world. This year?s fair is expected to surpass the 2010 figures. Here are some examples of the new developments visitors can expect to see at the show.

Jan 1, 2013

By James C. Cobb

Middle Pennsylvanian (Desmoinesian) coals of certain areas of the Illinois and Forest City Basins contain epigenetic sphalerite and associated minerals in veins, clastic dikes, cleat, and other small-scale structural features. The presence of sphalerite in these coals records information about the geology of coals and coal basins, and represents a potential source for zinc as a byproduct of coal production. Origin of Sphalerite in Coal The origin of sphalerite in coal suggested by Cobb (1) involves sphalerite precipitation from zinc-bearing ?Na-Ca-Cl brines upon contact with sources of sulfur in the coal bed, e.g., pyrite, H2S, and organic sulfur. These brines were essentially at the temperature of the host coals as determined by fluid-inclusion thermometry and vitrinite-reflectance studies. The migration of these brines into coal beds may have been caused by compaction of sediments due to continued sediment loading of the coal basins. Zones of high permeability such as sandstones and the coals themselves presumably acted as conduits for the movement of the brines. The open spaces where sphalerite was deposited resulted from minor deformation associated with differential compaction and cleat formation enhanced by volume shrinkage during coalification.

Jan 1, 1982

By Steven W. DeCou, Marcus R. Jensen, Stephen Navin

The Lake Mead Intake No. 2 is a project constructed for the Southern Nevada Water Authority which includes a 12-foot diameter lake tap and intake shaft constructed in over 225 feet of water; 1650 feet of 16x14-foot horseshoe-shaped tunnel leading to a forebay that is 165 feet long, 35 feet tall, and 30 feet wide; twenty-two 4-foot diameter steel lined well shafts extending 325 feet from the ground surface to the forebay; 3500 feet of 12-foot diameter pipeline crossing a bay in Lake Mead that has water depths of up to 80 feet; and 2700 feet of 9-footdiameter steel-pipe-lined tunnel. Major site grading for a future pumping station in the area above the forebay is also included as part of the project. The project is on the schedule’s critical path for completing the first phase of a $2 billion water supply program for the Las Vegas Valley. In this paper, the owner, the designer and the construction manager present a discussion of the risk management strategies that were used to control costs, minimize project delays, and facilitate problem resolution. The discussion includes an assessment of the effectiveness of the risk management strategies in meeting these objectives. This paper will be of interest to owners and engineers planning underground projects, especially those projects that present unique risks during the construction phase.

Jan 1, 1999

By Dennis F. Koschak

Production tests at Reserve Mining Company's iron ore pelletizing plant established that rubber-lined balling dm produce a green pellet equivalent in quality to those produced in conventional balling drums equipped with reciprocating cutter bars. The flexing action of the rubber liner prevents concentrate buildup in the drums, eliminating the need for a cutter bar. Advantages of the rubber-lined drum includes a reduction in maintenance and operating manpower, reduced bentonite consumption with less drum surging, reduced power consumption, and improved drum on time.

Jan 1, 1983