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By George A. Takach

The U.S. Bureau of Mines is conducting research with the goal of automating underground coal mine roof bolters for greater mine safety. In the project described here, the Bureau has focused on automating the drilling portion of the drilling and bolting cycle. A drill monitoring system designed and developed by Parvus Corp. of Salt Lake City. UT, was placed on a Bureau model roof- bolting drill. The drilling parameters of torque, thrust, rotation rate, penetration rate, and position are monitored through sensors connected to an asynchronous, control-oriented local area network (LAN) that communicates with data-accumulating and data-processing nodes. By placing microprocessors at the two data nodes and at the valve control nodes, and combining these nodes with a personal computer (PC), the monitoring and control system can achieve parallel processing capabilities. Such capabilities are referred to as locally intelligent distributed processing. Only data that have changed significantly are reported through the LAN to a supervisory control and data acquisition (SCADA) system mounted on an IBM- compatible 80286 PC. The SCADA system displays the values of the drilling parameters and calculates the specific energy of drilling, which is then used as an indicator of the type of rock being drilled. Besides monitoring the drilling process, an operator at the computer can control the rotation and thrust of the drill from a remote location through the SCADA program and can set drilling parameters on the basis of observed values of the specific energy of drilling.

Jan 1, 1992

By R. C. Jr. Babcock, V. S. Znamensky

The Pyke asbestos deposits were discovered by Kennecott Explorations (Australia) Pty. Ltd. in 1969 during the course of base metal exploration on the South Island of New Zealand. Extensive occurrences of chrysotile asbestos were found associated with the Red Mountain ultramafics in the headwaters of the Pyke River, and to the north and south along the ultramafic belt for a distance of 70 km. Surface evaluation and drilling by Kennecott in 1970 and 1971 identified numerous small deposits of good grade fiber in the Little Red Hills between the Pyke and Barrier Rivers. Additional drilling and three adits have been completed by other companies since that time. The property is presently held by Lime and Marble, Ltd., of Nelson, New Zealand, and Kennecott Explorations (Australia) Pty. Ltd. This chapter presents the regional and local setting of the asbestos deposits, including the geology and nature of mineralization. In addition, the exploration methods used by Kennecott in the discovery and evaluation of these deposits are outlined. Subsequent work by other companies is mentioned, but not de- scribed in detail. This subsequent work did not alter Kennecott's conclusions or produce any serious changes in the interpretation of geology and mineralization. The author acknowledges the contribution of the many employees of Kennecott Explorations (Australia) Pty. Ltd. who have been involved in the project. In particular, thanks go to Ramon Farmer, N.G. Corner, and A.W. McConie, who were responsible for completion of field work and reporting on the project. The responsibility for the conclusions and interpretations of this chapter are solely that of the author and result from his involvement in the discovery of the deposits and management of the exploration program. REGIONAL SETTING Ultramafic rocks on the South Island of New Zealand are thought to be Permian in age and occur between crystaIline and metamorphic continental rocks of Precambrian through Cretaceous age in the west, are thought to have once been part of the Antarctic subcontinent, and the extensive geosynclinal graywacke deposits of the Mesozoic New Zealand geosyncline in the east. They consist of the Dun Mountain ultramafics, a 130 km long segment of ultramafic rocks located at the north end of the South Island, and the Red Mountain ul- tramafics that occur in a zone 200 km long in the south half of the South Island as shown in Fig. 1. These two belts, once contiguous, have been offset a distance of 560 km by the still active Al- pine fault, which is analogous in character and offset to the San Andreas fault of the United States. The ultramafic rocks occur within a sequence of Permotriassic volcanic and sedimentary rocks that probably formed at the eastern margin of the continental plate. The ultramafics appear to be tectonically emplaced between Permian lithologies in the Dun Mountain belt (Coleman, 1966), and at the base of or between Permian volcanics and sediments in the Red Mountain belt. The Permotriassic ultramafic volcanic sequence of the Red Mountain ultramafic belt appears to be a typical ophiolite sequence. Ultramafic rocks, mixed mafic intrusive rocks and volcanics, volcanic rocks, and volcanoclastic sediments occur in apparent superposition from east to west in the area of Red Mountain. Farther south, ultramafic rocks are associated with basaltic volcanic rocks and some sediments, and still farther south are emplaced entirely in sediments. These structural compIications of the normal ophiolite sequence have resulted from the coincidence of Permian subduction, early Mesozoic extension and sedimentation, and Cretaceous subduction along the same plate margin (Landis and Bishop, 1972). The general geology in the area of the Red

Jan 1, 1986

By John A. Shuster

INTRODUCTION Controlled ground freezing for mining and construction applications has been in use for over a century. Despite the great technological evolution which has occurred during this period, ground freezing is still used on projects today with much the same basic technology as that used originally over 100 years ago. Major developments have occurred in the separate fields of frozen soil mechanics, refrigeration, and heat transfer analysis. However, except for a few projects in Europe and Asia, these developments have not been combined to upgrade ground freezing techniques to their potential level. In view of this situation, it is believed desirable to examine the art of ground freezing in light of recent technical developments, together with highlights on some of the apparent advantages, disadvantages and economics of the various alternative approaches. The purpose of this paper is to attempt such an examination, with particular emphasis on the practical application of presently available technology. GENERAL ADVANTAGES AND DISADVANTAGES Ground freezing may be used in any soil or rock formation, regardless of structure, grain size or permeability; however, it is best suited to soft ground rather than rock conditions. Freezing may be used for any size, shape or depth of excavation and the same physical plant can be used from job to job despite wide variation in these factors.

Jan 1, 1997

By R. Lai

This paper describes the application of a cyclonic flotation column (CFC) for coal cleaning. A CFC makes use of centrifugal force to create a density gradient in a column to augment the froth flotation process. In a CFC, a series of angular helical inserts is attached to the wall of a conventional column, and coal slurry is mixed with a series of impellers attached to a central shaft. The hydrophobic froth concentrates near the center shaft and moves upward, while the relatively heavy hydrophilic particles concentrate near the wall and are guided downward by the helical inserts. The results of pyritic sulfur removal from an Upper Freeport coal during CFC flotation are discussed.

Jan 1, 2003

By R. Kingman

At Tahawus, New York, National Lead Company operates the MacIntyre Development, This operation produces 10,600 long tons of ore per day for crushing, 8,000 tons for grinding and processing, of which 2,000 tons per day reports as tailing for disposal in an impounded tailing storage area. With the change in location of mining operations at the mine of National Lead Company, a change in the area for tailing disposal by gravity became necessary, This called for the diversion of tailing from near the proposed mining area to areas more favorable for long term storage by gravity. In order to avail the operation of maximum storage for the future, a uniform minimum grade launder was proposed with a minimum velocity and maximum outfall at the discharge. Disposal of the gravity and flotation tailing was formerly accomplished in open ditch from the concentrator at a grade of 1.5 percent. It was desirable to design the new launder at grades less than this for the greater storage elevation.

Jan 1, 1966

By Michael Gay, W. H. Hansmire, G. Rippentrop, V. S. Romero

The new Tren Urbano heavy rail transit project in San Juan, Puerto Rico has one very significant part, the Río Piedras Contract, being constructed underground. This paper will give an overview of the tunneling work that started construction in1997. Design-Build procurement for tunneling is addressed. The new and modern transit system in San Juan will be 17.2 km (10.7 mi)long and have 16 stations in its first segment of construction, which is due to open in 2001. The line connects the city center district of Santurce to the outlying suburban municipality of Bayamón. All construction is being done under design-build contracts as a demonstration project funded by the Commonwealth of Puerto Rico and the Federal Transit Administration (FTA). The Río Piedras Contract is completely underground and involves practically all types of construction in soft ground. One station is built as cut-and-cover at the University of Puerto Rico. One portion has twin tunnels to be driven with an Earth Pressure Balance Machine (EPBM) and lined with one-pass precast concrete segments. Another has four short tunnel drives at a turnout that will be constructed with an initial support of shotcrete and lattice girders (i.e., the New Austrian Tunneling Method of construction). The most complex construction is the Río Piedras Station, which is being built as a stacked drift with a total of 15 individual tunnel drifts. After being sequentially excavated and concreted, they will form the arch of the 19 m (62 ft.) wide by 16 m (53 ft.) high cavern station. This structure is excavated in soil with less than 5 m (16 ft.) of cover to overlying historic buildings.

Jan 1, 1999

By Ramkrishna Agarwal

A low grade iron ore is mined underground at Grace Mine using the panel caving method. Most of the development work is located in footwall. The runways for LHD equipments are heavily supported with steel sets on five foot centers. The sets are embedded in two to three feet of concrete. The initial cost of support is one of the largest single costs of production. During the process of ore-win¬ning, supports frequently fail, necessitating expensive repair. There is no systematic pattern to the failure of supports. A rock mechanics program was launched to isolate causes and their relative contributions to the failure of supports. The preliminary results are presented. A typical portion of a runway is instrumented to monitor rock mass movements around the runway and the corresponding response of supports as various mining activities are carried out in the neighborhood. We believe that such a program is a prerequisite to any remedial measure to alleviate pressure problem at Grace Mine.

Jan 1, 1973

By George M. Potter

During the late 1960s the mining industry became interested in USBM's efforts to develop the gold-silver heap leaching process. In the last 10 years, successful commercial heap leaching applications increased. The process provides a relatively low-capital means of processing treatable ores with reasonable operating costs. Present gold and silver prices compared to capital and operating costs favor the continued growth of the heap leaching method. The heap leaching process is defined as the percolation leaching of relatively coarse gold-silver ore piled on an impervious surface. To date, dilute alkaline cyanide solution is the lixiviant of choice. Other leaching reagents such as thiourea and hypo have been suggested, although they are not currently used in heap leaching practice. Ores may he run-of-mine in size or crushed as fine as about 10 mm. Gold and silver-bearing so¬lutions draining from the heaps may be processed in activated carbon columns to recover the metals, followed by stripping and metal recovery, or treated by the Merrill-Crowe zinc dust precipitation method. All solutions are generally recycled to the leaching step, and the heap leaching system is relatively easy to control from an environmental viewpoint. One advantage of the heap leaching process is its flexibility. Plants may be very simple, comprising leaching of uncrushed ore on a locally-obtained clay-lined pad and shipment of gold and silver recovered in the form of loaded carbon or zinc precipitates; such a plant would have a relatively low capital investment. More elaborate plants for larger ore bodies may be planned to include crushing, cyclic pad use, and done gold-silver recovery. General planning is similar in each case. This article outlines some key factors in designing heap leaching operations and discusses how these factors are applied to develop a working operation. Since individual design requirements and local costs vary so much, only a few general comments on costs are included.

Jan 3, 1981

By Lester F. Sanford

Located in the Santa Cruz Mountains eight miles north of the City of Santa Cruz and inland from the coast, lies a typical beach sand consisting of quartz and feldspar grains of the Santa Harguerita formation of the middle tertiary age, Reserves of over twenty-five million tons of this sand form the deposit presently being harvested by Pacific Cement & Aggregates, a Division of Lone Star Cement Corporation. The deposit ranges from 350 to 700 feet above sea level and varies from two percent passing a 200 mesh screen to ten percent retained on a ¼ inch screen (see Figure '#l) In 1929 the first sand plant went into operation at this site. It was replaced by a new plant in 1937. This plant continued operation until the middle of 1965 when replaced by the modern plant described in this paper.

Jan 1, 1967

By Bruce H. Mason

The exploration for a commercially acceptable deposit of limestone is consid¬ered by many to be a relatively easy task; however, trying to locate a zone of high calcium limestone of economic thickness within a formation, which outcrops only in a narrow band varying in width from a quarter mile to ten miles, adds considerably to the normal problems experienced during an exploration program. The existence of varying glacial and karst features in the outcrop area intensified the problems encountered and complicated the interpretation of the economic value of the deposit. This paper highlights a recently completed five year exploration program during which approximately 3,900 acres of ground in seven civil townships were evaluated as potential sources of high-calcium limestone. Details are given with respect to the final site chosen and the methods used in determining the suitability of the site. This site exhibited many karat features and several methods were utilized to determine the effect of these features on the gross characteristics of the deposit. Aerial photography for both mapping and interpretation were utilized. Black and white panchromatic photography, black and white infrared and color infrared photography were flown. Resistivity, diamond core drilling and close-interval angering were used to supplement the information obtained from the aerial photography.

Jan 1, 1974

By D. Morin, J. Villeneuve, S. Foucher

The development of new processes has to follow "best practice" rules in order to be technically and economically as efficient as possible. However, innovations, new process routes and new rules are continuously emerging to minimize financial risk and maximize environmental compliance. Process simulation, which offers a complete overview of the flowsheet, makes it possible to cope with this new challenge-minimizing waste production and water consumption. Furthermore, simulation provides an estimate, at the early stage, of the cost of alternative technical routes. Four examples involving biotechnological circuits are presented, both at the design and commissioning stages.

Jan 1, 2000

By Li Honggui, Liu Maosheng, Zhao Zhongwei, Sun Peimci, Li Yunjiao

Leaching of Shizhuyuan low-grade refractory tungsten ore was carried out in a mechanically activating reactor. The effect of experimental parameters-temperature, amount of Na2C03, addition of NaOH, ratio of liquid to solid and leaching time - on the recovery of WO3 was studied. The WO3 recovery up to 96.99% have been achieved when the tungsten ore was digested by soda not more than three times the stoichiometric amount at 185-195°C for 1 .O-2.0 hours. Iso-extraction countour diagrams were drawn to illustrate the effect of various parameters on leaching. The WO3 recovery could be expected to increase 10-15% compared to that of conventional soda autoclave process.

Jan 1, 1995

By Walter E. Heinrichs

To many, petroleum exploration and successful geophysics , are partly synonomous, This is not because natural petroleum is usually concentrated as a liquid, nor certainly not because oil can be detected directly. The reason is Chat geophysics helps to at least better understand and sometimes, to even explain the essential geology involved. That groundwater is similarly a liquid with all but a few of its basic geologic relationships practically identical to petroleum, seems to have escaped many of those most interested and responsible for complete geo-hydrologic knowledge. The paramount need to use every means at our disposal for maintaining and expanding our crustal resources reserves are generally obvious, However, in view of the rapidly mounting requirements, continual re-emphasis is worthwhile.

Jan 1, 1963

By Nicolae Dobritoiu

From experience and scientific references it is known that during information processing, the following error types are transmitted: technical, analogy errors and method errors. For decreasing the value of these errors, especially of the method ones, old algorithms should be perfected and new ones should be developed for processing, interpreting and achieving the graphical layout by means of automatic data processing. In this respect, we propose a new deposit model based on numeric mathematical modelling which requires the use of automatic data processing. The utilization of the numeric model of the proposed deposit, allows the obtaining of the following advantages: • the model is used for any deposit form; • it is used for the calculation of deposit resources (volume, weight, and content); • it is used in design due to the facility of obtaining sections through the deposits area; • it eliminates at "0" the errors of graphical data transcription; • the use of the model imposes a uniform geological research; • the algorithm is transposed in a package of programs.

Jan 1, 2002

By D. S. Cavers

INTRODUCTION This paper discusses aspects of rock engineering applicable to surface gold mines. Discussion particularly centers on areas in which rock mechanics can enhance the mine productivity or profit- ability. Methods of analysis are discussed briefly but for more detai1s the reader is referred to the appropriate references. A team approach to the overall design of the pit generally pro- duces a better result at an overall lower cost. In particular, money is wasted by asking for a "report on slopes" and then input- ting this slope angle into a pit design and economic analysis study without further reference to the geotechnical engineer. Pit slope angle depends on slope orientation, location, pit shape, pre-existing discontinuities and mining methods. Preliminary slope angles can be produced but optimization depends on ongoing inter- action between the mining engineers, geologists and geotechnical engineers. This interaction can a1 so substantially reduce overall design time which may be critical in bringing remote plays into production. Most surface gold mines in North America are in igneous or metamorphic environments. Rock mechanics aspects discussed in this paper will be discussed with reference to these environments al- though most of the principles and comments are applicable to sedimentary environments as we1 1.

Jan 1, 1987

By W. Bassow

In June 1972, when the United Nations convened its historic Conference on the Human Environment, only 24 countries had established government agencies with environmental responsibilities. Of these, 11 were in the industrialized world, 13 in the Third World. By 1985, the number had dramatically surged to a world-wide total of 145, with the greatest growth among the developing countries to 110, an increase of almost 1000%.

Jan 1, 1988

By James P. Odendahl

Missouri is a state rich in mineral commodities. There is a variety of types of mining as well as minerals in the state. Different phases of mining are controlled by a variety of state and federal laws. What I hope to do today is to present briefly some of the interaction and interplay that has occurred in the recent years between the mineral industry and the Missouri regulatory agencies, as well as some of the interactions by federal agencies. First a little history which dates back to the late 1600's. For many years Missouri has been a leader in the production of lead and zinc. In fact, recent studies have indicated that Missouri produces better than three-fourths of the nation's present lead supply. Less well known but important resource is iron mining. Some of these operations were the source of confrontation during the Civil War. Major battles were fought in and around Ironton, Missouri where iron mining has occurred for many years. One of the largest pelletizing operations in the state is currently located within the city of Ironton. Joplin, Missouri, the home of Thomas Hart Benton, the famous Missouri painter, has a history of lead and zinc mining, going back to the later 1800's. Many of the paintings by Benton contain reference to the early days of mining in Missouri. There is a Benton mural in the City Hall at Carthage depicting the early days of lead mining in that area. Later, the center of lead mining moved to southeast Missouri near Bonne Terre and Flat River. The names of the towns in this area reflect the history of mining, examples - Leadington, Old Mines, Rivermines, etc. The history of lead mining in Missouri has been referred to in some detail in various publications(l).

Jan 1, 1977

By W. V. Bluck

Higher coal quality is being recognized in potentially lowering the cost of power as measured at the bus bar. Assessment of potential coal supplies for most any given power plant is now going beyond buying at the lowest delivered fuel cost and is now taking into consideration other factors such as handling, storage, pulverization cost, boiler fouling, post combustion cleanup, and waste disposal costs. New measurements of quality are being considered now by those producing and those consuming the fuel by assessing numerous variables in the total fuel cycle to achieve the lowest possible power costs.

Jan 1, 1983

By Ernest Y. Baafi

This paper describes the results of a series of comparative studies in which polygonal, IDS, and kriging were compared for their local estimation accuracy. The specific objective of this study was to determine the impact that the particular nature of the mineralization has on the results of such comparative studies. The study was performed on simulated coal deposits and the evaluation parameter chosen was the coal thickness. For this study, many conditionally simulated deposits having different degrees of seam thickness continuity were first developed. Each simulated deposit covered an area of 30,000 ft x 30,000 ft which was, in turn, subdivided into 100 mine planning blocks of 3,000 ft x 3,000 ft in size. Thickness estimation was made for these mine planning blocks using surrounding DDH assays. In all cases tested, e.g., from a perfect continuity to a complete lack of continuity in coal seam thickness, kriging gave the best estimates among the three, followed by IDS and polygonal methods. As expected, the relative efficiency (i.e., superiority) of kriging over other estimators was highly dependent on the nature of mineralization.

Jan 1, 1982

By L. A. Clark

Although vein-, syenite-, and pegmatite-type deposits are known in Saskatchewan, recent intense exploration stems from discovery of several exceptionally high grade uranium and uranium-nickel deposits locallized near the basal unconformity of the 1.3-1.4 b.y. Athabasca Sandstone Formation. Graphitic basement rocks and post-Athabasca faulting or brecciation coincident with the unconformity are important in locallizing uranium deposits which form as tabular, shoe lace-like bodies with grades averaging over two percent and containing up to 50,000 tonnes U308. Some deposits have similar nickel contents. A few published sandstone analyses average 0.8 ppm uranium while basement granitoid and meta-sedimentary rocks vary from 0.5 to 20 ppm. In the proposed genetic model, traces of uranium are leached from these rocks by oxidized formation waters sweeping through the sandstone and along faults. Solutions are reduced and uranium is precipitated as basement graphitic meta-pelites are encountered along brecciated fault zones.

Jan 1, 1979