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By Scott G. Britton

In the real world of coal mining, the bottom line for almost every support project decision is economic (i.e., what is it going to cost?). Up to this point, I have discussed the methods to improve the performance of typical support projects by better installation, materials, and techniques, thus lowering the impact of the bottom line cost. In this chapter, 1 shall explore what costs are relevant in mining construction, and how these costs are developed. The chapter centers around two major discussions: (I) developing cost accounting techniques, and (2) cost-estimating procedures for support construction. Each focuses on the fundamentals of practical cost considerations necessary for decisions on construction projects underground. Since cost accounting, economics, and investment planning are all subjects which warrant complete discussions on their own, this chapter will focus on distilling the important concepts required by a planning engineer into an easily understandable presentation.

Jan 1, 1983

By R. K. McFarland, E. S. Diamant, L. Blake

A number of concepts for basing strategic missiles facilities deep underground have been developed within the defense industry. Recently, several contracts were let by the Air Force Ballistic Missile Organization to better develop system concepts for Deep Basing and Rapid Egress of Missiles from these facilities. A particular challenge of the Deep Basing Concept is the need for the excavation of egress tunnels or shaft from the deeply based facility to the ground surface, in a rapid and reliable manner. This Paper describes a conceptual MX-Deep Basing Facility, the technical issues associated with its design and construction, and potential means for achieving rapid egress from this facility. Manuscript not received in time for publication.

Jan 1, 1983

By Yoneji Kanoh, Masahiko Ohtsuka

In Japanese tunneling history, it has commonly been accepted that the long-round driving is difficult due to the complicated geological condition. Therefore, the maximum past record has been less than 3 m per round. A new record of advance was established in the 99 m2 headrace tunnel of Imaichi Water Power Station Project with an advance of 239.5 m in a month by drilling 3.9 m deep blast holes. The geology of the headrace tunnel composed of pyroxine andesite (ie. 960-1770 kg/cm2, VP3.1-4.3 km/s) which had several clay seams and open cracks and was moderately weathered. Automatic shotcrete machine was used for shotcreting. Rock support was specified according to the N.A.T.M. with each different rock type. The contractor achieved a remarkable tunneling advance not earlier experienced in Japan.

Jan 1, 1983

By Gary S. Brierley, John W. Critchfield

This paper is a case history of a subsurface exploration program conducted for a system of sewer tunnels in upstate New York. The focus of the discussion is a non-technical outline of how the exploration process was organized to efficiently produce a large body of geological and geotechnical data. A brief description of the project and geological setting is provided, the scope of the exploration program is summarized, the logistics of collecting, processing and reporting subsurface data is outlined, and recommendations for management of explorations applicable to any rock tunnel are provided.

Jan 1, 1983

By Ching L. Wu, Bolek Chytrowski, Peter Frobenius, Dale Roberts

During the past few years, the first stage of the Waste Isolation Pilot Plant, (WIPP) which consists of an exploratory shaft, a ventilation shaft, shaft stations, access drifts and test rooms, has been under construction. Construction of the first stage is scheduled to be completed in the summer of 1983. The U.S. Department of Energy (DOE) is constructing the WIPP facility to demonstrate the feasibility of disposing of defense-related nuclear waste in the bedded salt deposits of the Delaware Basin near Carlsbad, N.M. The project promises to be a proving ground for underground nuclear waste storage facility design and construction. The completed underground plant will extend over an area of 647,500 m2 (160 acres), and 1,360,500 metric tons (1,500,000 tons) of salt will be excavated. The first stage of the project, the Site and Preliminary Design Validation (SPDV) Program, provides for full-scale construction of the major components of the underground facility. Shaft construction and underground development are described. Rock bolt installation is performed as required for roof control. Geotechnical instrumentation is installed to monitor the behavior of underground openings. Direct observation of the constructed shafts, shaft stations, and underground openings is expected to confirm the adequacy of the underground design and allow full-scale construction of the first U.S. underground nuclear waste storage facility to proceed.

Jan 1, 1983

By Dennis R. Twining

Recently a mining analyst for a major bank called me to say that during his travels he had encountered an electric utility interested in a new uranium supply. Since we produce uranium as a by-product of phosphate operations rather than as a primary product, he assumed we simply sold our output in the spot market and that a new prospective purchaser would be of interest to us. This assumption was incorrect; the uranium had already been sold on a long term basis at terms more favorable than the currently depressed spot market. From the outset our approach to the marketing of uranium was based on the principle that by-product marketing is not unlike primary product marketing. This was particularly appropriate in the case of uranium, as we were planning a considerable technical and capital commitment to a new business. This illustrates: that the fundamental principle in by-product marketing is to follow a primary product strategy; that the terms "by-product" or "co-product" are creations of accountants; that they have no place in marketing decisions! Traditionally, the term "by-product" has implied that only a secondary marketing effort is required. Recent history has contradicted that view by demonstrating that by-product values can have marked impact on a mine's revenues and costs. In fact, by-product values can spell the difference between success and failure.

Jan 1, 1983

By Mark E. Gershon

Conventional methods of drillhole site selection are reviewed briefly. Two approaches using geostatistics are then discussed, both of which have been shown to yield improved results. Finally, a branch and bound algorithm is described which will select the best locations for drilling from a user specified number of possible drill sites. Two options are discussed. First, the user can specify a maximum drilling investment or a maximum number of drillholes and the program will select the locations yielding the minimum estimation variance. This amounts to getting the most for a given investment. Alternatively, a maximum tolerable estimation variance can be specified and the program will select the number and location of the drillholes to obtain the desired information at a minimum cost. Another benefit of the approach is the quantification of the tradeoffs between investment and information obtained.

Jan 1, 1983

By T. A. Rundle, K. Kim, W. M. McCabe, E. C. Gregory

Overcoring tests were conducted at the Near-Surface Test Facility(NSTF) to assess the suitability of five techniques (U.S. Bureau of Mines borehole deformation gauge (BDG), Commonwealth Scientific and Industrial Research Organization (CSIRO) hollow inclusion stress cell, Luleå triaxial gauge (LuH gauge), and Council for Scientific and Industrial Research (CSIR) doorstopper) for in situ stress determination in a closely jointed basalt. This effort is in support of the Basalt Waste Isolation Project, which is studying the feasibility of locating a nuclear waste repository in the basalts of the Hanford Site in southeastern Washington. This paper presents the results from the overcoring study that formed the basis for selection of two techniques to be used during the further exploration of the basalt formations at depth.

Jan 1, 1983

By Eckart Schneider

PROJECT The Walgautunnel is the heart of a new hydro scheme in Western Austria, which is supposed to go into operation in 1984. With it's length of 21,4 km, a bored diameter of 6,25 m and an internal operating pressure of 13,5 bar it will be the largest water conducting tunnel in Austria. Even compared with some of the country's world-famous highway tunnels like 'Tauern' or 'Arlberg' it has to be regarded as a major tunneling project. Owner is the Vorarlberger Illwerke AG, a power corpo¬ration founded in 1924. In the course of the past 6o years this company developed the 'Werksgruppe Obere Ill - Lünersee', consisting of 6 major power plants and 4 large reservoirs. The installed capacity is 1.114 MW in the generating and 529 MW in the pumping mode. The total power output amounts to 1.916 GWh. The water for power generation comes from the glaciers of the Silvrettagroup, as this corner of the Austrian Alps between Vorarlberg , Tyrol and Switzerland is called. The Walgauwerk utilises all the water accumulated by the existing schemes as well as the so far unused run-off water, passing by in the river Ill. The intake to the Walgau-Tunnel is situated right beside the lower reservoir of the recently completed pump-storage plant 'Rodund II' at an elevation of 64o m above sea level. Though the head is a mere 162 m, 1 billion m3 of water will generate 356 GWh per annum. The power-output of the two Francis turbines is 86 MW.

Jan 1, 1983

By Lawrence A. Engel

The idea of using apron feeders for in directly feeding crushers is not a new one, it has been used for many years. To the best of our knowledge, the first apron feeder was used for bulk material handling in 1893. Since that time many design innovations have been introduced, with perhaps the most effective one being, the application of crawler tractor components in the feeder construction. This design was first introduced to the mining industry in 1954 by, national iron company. These feeders were used in the handling of run-of-mine iron ore on the Minnesota iron range, at the rate of 1,000 ltph. The material was fed over a grizzly to a jaw type of crusher. The crusher output was also handled by an apron feeder. Today, the apron feeder is being used in hard rock surface mine operations feeding crushers at rates of 5,500 ltph and over.

Jan 1, 1983

By J. W. Scott

The problems involved in installing, maintaining, and operating large vibrating screens have been summarized and discussed, based on a survey of current use of such screens in selected North American mineral processing applications. Practical, effective solutions for the more serious common problems are described, along with some recommendations on design practice for specifying, selecting, and installing large screens.

Jan 1, 1983

By W. L. Staker

The Bureau of Mines investigated selective extraction of Au and Ag from a low-grade Au ore containing Hg. Gold and silver were extracted from the ore in cyanide slurries, and Hg extraction was suppressed with sodium or calcium sulfide. Maximum Au extraction and minimum Hg extraction were obtained using solutions containing 0.34 lb NaCN/ton of solution. Increasing the cyanide concentration increased Hg extraction without increasing Au extraction. Mercury extraction from the ore was suppressed with 0-5 to 2.9 Pb CaS/lb Kg in the ore. Gold-to-mercury ratios of 100:1 to 400:1 were obtained in the leach solution, and on the activated carbon in a CIP circuit.

Jan 1, 1983

By Thomas A. Thorson

Bentonite is a common name applied to a variety of clays that develope swelling properties when associated with water. Useful bentonite deposits occur in many Western and Southern states. Their origins may consist of the alteration of volcanic sediments or the decomposition of shallow lake deposits. The specific type of bentonite that will be discussed in this review will be only the Western or high swelling sodium type bentonite that is mined primarily in Wyoming. Wyoming bentonite first entered the market in the late 1880's when it was used as an oil absorbing cosmetic. In the 1920's it was discovered that superior binding properties were present which created new opportunities in pharmaceutical, animal feed, and steel foundries. The swelling properties that were exhibited by the high swelling Wyoming bentonites soon led to its use in oil exploration when the rotary drilling process developed a need for multipurpose fluids. Bentonites in general and Wyoming bentonite in particular have fascinated chemists and process development specialists since the 1920's. There exists a long list of industrial uses that has led to hundreds of patents and extensive literature reviews. The binding and swelling properties are developed as a result of large surface areas and high cation exchange properties. Water, being a di polar molecule, attaches to the ionic vacancies and forms a network of tightly held water particles which in turn produces an impermeable seal or a binding characteristic in unconsolidated powder. Newer uses for Wyoming bentonite that once again utilized the binding and swelling properties include the pelletizing of iron ore and a vast array of civil engineering applications including slurry trenching, lagoon sealing, and garbage landfill sealing.

Jan 1, 1983

By Young C. Kim

In the past, underground coal mine planning has traditionally focused on the mine design n aspects concerning safety and efficiency in the quest to produce low cost coal. Very little attention has been given to coal quality control aspects of mine planning at most of the underground coal mines within the U.S. With the enactment of the clean air act of 1970, the generally high sulfur content of coal has become a major concern for the coal-fired power plants in the east. Similarly, the ash and the BTU contents of coal are of equal importance from boiler efficiency standpoint. Thus, the time has come when the coal mine planning must incorporate the coal quality control aspects as well as the traditional safety and efficiency aspects.

Jan 1, 1983

By Gary P. Thomason

We have all heard a great deal about how various projects were financed or certain companies were successful in obtaining a bank loan. There are many more projects and companies who fail to get the money they need. At least a portion of these failures, and a large percentage of the frustrations connected with even the successful financings, are a result of not understanding the process of obtaining money. Recent years have seen a proliferation of sources available to finance minerals operations, but let me assure you that these represent only a minor portion of the minerals financing market. The fundamental source of borrowed money to almost all minerals related companies remains the banks. Therefore, understanding the "Loan Approval Process" can easily mean the difference between getting the money or not. In the following pages I hope to provide some insight into what I define as the loan approval process. Having pre-offered my definition, I intend to delineate the various stages of the process and the planning and information I believe should be contained in each. My ultimate goal is to help you think like a banker and, in so doing, stay on top of the process so that you can successfully obtain the funding necessary for your projects.

Jan 1, 1983

By George A. Savanick

Borehole (slurry) mining, in which a tool incorporating a water-jet cutter and a downhole slurry pump mines phosphate through a borehole, was field tested in northeastern Florida as part of a Bureau of Mines program to increase the domestic availability of critical minerals. Approximately 1700 tons (1.54x106 kg) of phosphate ore were mined at 40 tph (10.1 kg/s) from a depth of 250 ft (76 m). The borehole was filled with water during mining for roof support and to assist slurry pumping. Underwater cutting was enhanced with an air-shrouded water jet. Mined cavities were backfilled to prevent subsidence after abandonment. Roof subsidence during mining was avoided only when the cavity was filled with water. Environmental monitoring before, during, and after mining included hydrological studies and measurements of water quality. Significant water quality changes occurred only in the zone being mined and were confined to the immediate area of the borehole.

Jan 1, 1983

By Bryson D. Trexler

Slope stability in open pit mines is governed by rock structure, rock quality, ground water conditions, blasting, pit geometry and excavation method. Of these factors, the control of ground water pressures often represents the primary tool to improve slope stability. Production equipment has recently been used to stabilize two slide areas by dewatering using blasthole drills for vertical holes and secondary drills for horizontal holes. This paper describes both of these dewatering programs and contrasts an earlier slope stabilization program that employed a subcontracted horizontal drill.

Jan 1, 1983

By Levent Ozdemir, Robert J. Evans, Russell J. Miller, William Sharp

This paper describes the specifications and capabilities of a 6 ft (1.83 m) diameter laboratory rotary cutting machine which was designed and fabricated under a Bureau of Mines (USBM) contract awarded to the Colorado School of Mines (CSM). The machine will be used for carrying out research and development programs aimed toward improving the design and operation of mechanical tunnel, raise and shaft boring equipment.

Jan 1, 1983

By Richard A. Brown, Robert D. Norris

By-product metals can be a significant source of revenue for a mining operation if their recovery can be accomplished without negatively impacting primary metal recovery. The main problem encountered in separating primary and secondary metals is to selectively control the solubility of the individually important metals with¬out affecting their ultimate recoverability As a class of hydrometallurgical chemicals, peroxygens have a versatility which permits the selective recovery of individual metal species. Peroxygens function as more than simple oxidants. They are effective solubility control agents and have proven utility in complexation, precipitation, dissolution, extraction, oxidation and reductive processes Peroxygens have been used commercially to recover by-products vanadium, uranium, molybdenum, and cobalt and have proven experimentally to recover rhenium, gold, silver, manganese and zinc

Jan 1, 1983

By David E. Thompson, Andrew F. McKown, Herbert H. Einstein, Amr S. Azzouz

INTRODUCTION Design of supports for underground chambers in rock has undergone considerable development. This becomes evident when comparing support dimensions of subway station caverns built in the U.S. over the past fifteen years. The Porter Square Station cavern, which is a part of the Massachusetts Bay Transportation Authority (MBTA) Red Line extension, is the latest in this series. It is approximately 168 m (550 ft) long, 21 m (70 ft) wide, and 14 m (45 ft) high, and has a permanent support of light steel ribs imbedded in a 0.4 m nominal (15 in) shotcrete lining. An extensive construction control instrumentation program made it possible to evaluate the performance of the cavern and its support. This evaluation, which is presented in this paper, was the objective of a research project sponsored by the Urban Mass Transportation Administration (UMTA) and jointly conducted by Haley and Aldrich, and MIT. The actually used design procedure was compared with other approaches, notably procedures based on Finite Element analyses and empirical rock mass classification methods. Support dimensions predicted with all these approaches were compared to the actual support and its performance.

Jan 1, 1983