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By Lennart Mukka

The Kiruna Mine in Sweden currently has three ventilation systems. The first two (a new and old system) serve the production areas. The third system is used for the facilities on the former main haulage level 775. That area includes offices and workshops for load haul dumpers (LHD) and drill rigs. The third ventilation system also covers the crushing and haulage on level 1045. At the present time, the total airflow for the mine is 1,600 m3/sec(3.4 million cfm). The current system serves the levels above the 775 level. The new one is for the levels between 775 and 1,085 m (2,540 and 3,560 ft), which are needed for the new ore body. When all of the production is below level 775, the old ventilation system will be closed down.

Jan 1, 2002

By Youngtak Ko, Wonnyon Kim

Korean contract Mn-nodule field in the NE equatorial Pacific is composed of seven sectors showing average water depths of 4,513 - 5,025 m. Of the various factors controlling the property of Mn-nodules, water depth has a potential linkage to chemical composition, shape and abundance of nodules. To clarify such a possibility, we review more than 20 years of research data in one of the northern sectors (hereafter KR1) where there is a marked contrast in water depth. High-resolution seabed mapping clearly separates a northern part from a deeper southern part, cutting across the middle of the KR1. In terms of nodule occurrence, manganese nodules in the deeper north are comparatively larger (2-4 cm) with rough surface (t-type) and discoidal shape (D-type), while those in the south are generally small (<2 cm) with smooth surface (s-type) and irregular shape (Itype). In addition, the nodules in the north have higher metal contents including Cu, Mn and Ni. Such connections of water depths to nodule occurrence and metal contents are commonly observed in the Korea licensed Pacific nodule fields. However, the relation between nodule abundance, size and water depth may be a different story. In KR1, nodule abundance and size are probably controlled by morphological features especially in the north. Seamounts in the north continuously provide rock fragments as new nuclei for the nodules. As a result, the nodules can not grow larger than 2 cm and show the shapes of newly formed nodules (i.e., smooth surface and irregular shapes). Such an interpretation is supported by anomalously high backscattered intensities in the side-scan sonar image map of the north, which possibly reflects a younger generation of magmatic activity.

Sep 1, 2014

By Fernando Muge

A complex pyrite orebody located in the South of Portugal (MO INHO) was exploited in the past by cut and fill methods until a certain level. It was decided to design a new plant for non ferrous metal extraction and the rate of production and exploitation method was modified accordingly. So, a sub level stoping (SLS) method was en visaged for the exploitation of the deepest part of the orebody (under 265 m level). For the planning of this SLS method, it was decided to perform a geostatistical study of the orebody, on the basis of the available information, which consists mainly of channel samples assayed for Cu, S, Zn and Pb.

Jan 1, 1979

By Michael G. Nelson, Sekhar Bhattacharyya

Between 1974 and 1977, a detailed study of coal pillar strength was conducted by the University of Utah at the Beehive mine in southeastern Utah. This study was funded by the U.S. Bureau of Mines, and included laboratory testing of coal samples, extensive field instrumentation and measurements, and finite element analyses based on the laboratory results. Recently, a similar analysis of the laboratory results and mine design geometry was completed using the LAMODEL program developed by NIOSH. The results of this analysis were close to the data collected in the field. This study allows comparison with the earlier finite-element analysis, and illustrates the utility of the LAMODEL software suite.

Jan 1, 2005

By S. Suwansawat, D. J. Maconochie, C. C. Chang

This paper describes the overall delivery of the tunneling for the Mass Rapid Transit Authority of Thailand’s Chaloem Ratchamongkhon Line in Bangkok and the constraints provided by the alignment. Eight earth pressure balance tunnel boring machines were employed under two major civil works contracts to drive approximately33 kilometers of tunnel in soft saturated ground beneath the crowded streets of Bangkok. Responsibility within the contract for building damage provided an inherent control for ground movement arising form tunneling when the right of way was narrower than the influence zone. These limits affect the earth pressure balance requirements and permissible ground loss. The methods adopted to limit ground movements and deal with the various obstacles to tunneling influenced the design and operation of the machines. The challenges provided by the need to tunnel through numerous lines of piled foundations of canal bridges and overpasses crossing the alignment are described.

Jan 1, 2001

By D. I. Smith

Constructing tunnels in congested urban areas requires tunnels to be placed closer together and with less cover than was previously necessary. Contract CQ031 of New York?s East Side Access project will construct four six-meter diameter bored tunnels in a three-up one-down ?T? configuration, with less than three meters of soil between the tunnels. Mixed-face rock and glacial till conditions with a high ground water table will be encountered under active railroad yards. The tunnels will also pass beneath the busiest railroad interlocking in North America with cover as shallow as three meters. This paper discusses the challenges of designing segmentally lined tunnels for these conditions.

Jan 1, 2008

By Walter C. Labys

There has been considerable growth in public enterprise institutions involved in mineral commodity markets. These institutions typically consist of trading organizations (STO1s), regulatory agencies, and mixed agencies. The particular character of these institutions varies according to whether they reside in developing countries, in Eastern Europe (COMECON Countries), in industrialized countries, or in the form of international agencies. The purpose of this paper is to explain recent attempts to assess the growth of public enterprises as well as their impacts on mineral markets and trade. Some earlier analyses of market impact made by the author have been up- dated for four major mineral markets: copper, tin, bauxite and iron ore. Conclusions are drawn regarding the dynamics of market structure changes and their impacts.

Jan 1, 1986

By Barrie Butt, V. S. Znamensky

The opportunity for an exploration geologist to follow a successful exploration project through the feasibility, financing, construction, development, and exploitation phase is rare. In addition, it is not often that the exploration geologist can be present during the mining of a deposit to explain why certain actions were taken or interpretations made, and to find out how these interpretations turned out in actuality. At the Woodsreef chrysotile asbestos mine in New South Wales, Australia, mining has been- in progress for seven years and the writer of this chapter has been intimately associated with the project during the five years of exploration and seven years of exploitation. The Woodsreef mine has had major production problems, the majority of which have stemmed from the unique characteristics of the ore body and fiber. Because of the latter feature, much research has been undertaken by Woods- reef and other scientific organizations in Australia, England, and Canada regarding the Woodsreef fiber. The answers to some of the problems have negated some accepted concepts of asbestos ore milling and led to the development of new techniques. Some of these new techniques include the adoption of microscopic fiber counts as a routine procedure, the modification of accepted evaluation procedures, the development of new machines for dedusting fibers, and the recognition of a fiber with a unique milling behavior pattern and, possibly, properties. The problems experienced can be broadly divided into those associated with the geology and the physical properties of the fiber. It is possible that the same features may manifest themselves in other deposits around the world, and if they can be recognized during the exploration stages, a feasiblity evaluation may be just a little closer to the actual. The Woodsreef chrysotile asbestos deposit (latitude 30°24&apos; S, longitude 150°44&apos; E) is located 80 km north of Tamworth, NSW, Australia. The mine has been in production for six years and has a present scheduled mining rate of 33.11 Mt/y. An eight rock line mill treats an average of 7000 t/day, after beneficiation, and yields fiber grades in the range of group 4 to group 6 with some floats. The estimated re- serves of 30.56 Mt, with an ore to waste ratio of 1:3.0, are contained in two main zones that are designated the North and South zones. Mining started in the South Zone in 1972 and then, be- cause of the higher ore value, moved to the North Zone in 1975. Presently, there are two distinct open cuts referred to as the South and North pits that will eventually be worked together. The Woodsreef mine is owned by Woodsreef Mines Ltd. and is operated by Chrysotile Corp. of Australia Pty. Ltd., and is one of only two producing asbestos mines in Australia. The second mine is at Baryulgil, (latitude 29°13&apos; S, longitude 152°37&apos; E), and is operated by a subsidiary of Woodsreef Mines Ltd. This operation produces about 500 t/y for a captive market. An exploration program is being conducted in the area surrounding this small producer with a significant degree of success. The concepts developed during the exploitation of the Woodsreef deposit are being incorporated in the evaluation of the Baryulgil area, and if the Baryulgil deposit proves to be eco- nomic it is hoped that this approach will eliminate some of the major crises that have beset the production at Woodsreef during the first four years of operation. The purpose of this chapter is to describe the Woodsreef deposit, and more important, to

Jan 1, 1986

By R. S. Shoemaker

It is said that there is nothing new under the sun and this is certainly true about refractory gold Ores. Ores which have been refractory to treatment have been the bane of the Metallurgist&apos;s life ever since gold has been recognized as a metal valued for its indestructability, malleability and beauty. Webster&apos;s Dictionary defines "Refractory" as; "Resisting control or authority, stubborn, resistant to treatment or cure, unresponsive to stimuli, difficult to corrode or draw out," And gives as a synonym the word "unruly." I don&apos;t think any metallurgist would disagree with these definitions as they quite accurately describe refractory gold ores as we know them and I wouldn&apos;t be a bit surprised if many of you in this room today had applied far stonger language to your own refractory ores in the course of your metallurgical test programs. Pliny the elder put it very well when he wrote in 79 A.D., Gold is the first of man&apos;s follies, Silver the second." Perhaps Pliny was speaking of "unassayable gold" or "incipient gold." These are truly refrac tory ores which probably existed before Pliny&apos;s time and although many people have claimed to have solved their metallurgy the untold wealth that lies within them has never been bankable. On the other hand, Virgil is his Aenead, could very well have been speaking of refractory ores when he wrote; "Quid non mortalia pectora cogis, auri sacra fames!" which translates as, Accursed thirst for gold! What doest thou not compel mortals to do. Certainly, gold was extremely rare at that time because it had to be recovered by much labor from the then refractory ores and their refractoriness caused the early metallurgists (or alchemists if you will) to seek an easier way to produce it; thus the long and fruitless search for the "philosopher &apos;s stone" which would aid in turn-

Jan 1, 1990

By F. Allen Meek

The Upshur Complex of Island Creek Coal Corp. consists of approximatly 35.000 acres of both surface and deep mine researves located in Upshur County West Virginia. The principle seams on the researve are the Middle and Lower Kittanning. Other mining in the area during the late 1960&apos;s and early 1970&apos;s produced surface mines that exhibited severely acidic drainage characteristics both during the mining phase, and after reclamation was completed. The Buckhannon River, the principal drainage for the area, is a high quality, lightly buffered stream, that is periodically stocked with trout. Because past mining had caused post mining acidic discharges and the Buckhannon River was a valuable recreational resource, mining permits for the area were put on hold by regulatory authorities, until solutions to the acid mine drainage questions could be addressed. In 1978, the director of the West Virginia Department of Natural Resources appointed a Task Force consisting of Industry, Regulatory. and Academlc participants. This Task Force was charged with gathering information and evaluating field procedures used during mining to prevent acidic mine drainage. In 1979, the group published a document titled "Suggested Guidelines for Mining in Potentially Acid Producing Overburdens" which summarized material handling and mining procedures that could be employed to help prevent the occurrence of post mining acid mine drainage. In 1982, a Technical Advisory Committee was appointed consisting of well known researchers in the field of acid mine drainage prediction and prevention. The group was charged with the task of conducting research in the field of acid mine drainage prevention. Mining conducted at the Upshur Complex between 1979 and 1986 employed various acid mine drainage preventative techniques recommended in the suggested guidelines manual and techniques concurrently being researched by the Technical Advisory Committee. Costs for the various techniques were documented and the resulting post-mining water monitored. The results of these evaluations are used by Island Creek in the planning of future mining operations in potentially acid prodcuing environments

Jan 1, 1991

By M. E. Poad

The Research and development review arrived too late to appear in the May issue. The competitiveness of the US mining industry in a world market depends on many factors. The introduction of new and innovative methods, though, can have a significant, long-term impact. As industry cuts back its own long- term research and development efforts, the federal government continues to provide the major support for mining and minerals research. The US Bureau of Mines works with the mining industry and the academic community to develop innovative concepts for the mining and processing of non-fuel minerals. The Bureau’s research focuses on exploration and mining technology, minerals and materials science, processing technology, health and safety and environmental technology. Mine design A conical caving system, being designed by the Bureau, would allow the development of low-grade ore bodies, early startup at lower initial capital costs and increased safety and versatility in development and production. This method is a form of mass caving that allows the ore to be drawn from a central loading point at the bottom of the cone- shaped caving zone (Fig. 1). A simulation laboratory model and computer analysis show initial promise for predicted performance. For tabular, flat-lying ore deposits, the Bureau is investigating a version of the Finnish slot-and-fill system. For this total extraction method, a pattern of rectangular panels is laid out. One panel is extracted in a series of parallel slots and is replaced by alternating-row pillars of backfill. After one panel is mined, equipment and operations are transferred to another panel. By transforming this rectangular layout to a curvilinear geometry, one continuous spiral can be mined without re positioning equipment. Instead of parallel slots and pillars aligned in a rectangle, the slots and pillars are arranged in a spiral.

Jan 1, 1992

By S. Harteis, D. Dolinar

Many mining operations rely on bulkheads to provide a barrier between impounded water or slurry and active mine workings. However, bulkhead failures could cause and have caused catastrophic flooding that puts the underground workforce at risk. The National Institute for Occupational Safety and Health1 (NIOSH) in collaboration with the Mine Safety and Health Administration (MSHA) is conducting research to evaluate the adequacy of existing design practices for water and slurry bulkheads. A key component of this research effort is documentation of the performance history and design parameters for bulkheads installed in underground coal mines during the last 20+ years. This research is part of a larger effort to develop general design guidelines and procedures for constructing and maintaining bulkheads that will help to ensure their long-term structural integrity, while significantly reducing the inundation risk for miners. This paper presents the results of NIOSH’s research to identify state-of-the-art bulkhead designs, including design criteria, leakage monitoring systems, and emergency warning systems. Underground observations and evaluations of existing bulkheads suggest that the most important design factors influencing their performance are the interface of the bulkhead with the surrounding strata and the potential magnitude of the hydraulic pressure to which they may be subjected. When a bulkhead has failed, leakage has generally been through the surrounding strata or along the bulkhead/strata interface, with the failure potential along the interface increasing with hydraulic head. It was also determined that development of a monitoring program to ensure the long term structural integrity of bulkheads is an important safety consideration. Current monitoring procedures range from weekly visual inspections to constant monitoring via pressure transducers and fluid level indicators. Where possible, these devices are used in conjunction with a computer based mine monitoring system to alert mine personnel when an emergency condition exists at the bulkhead installation.

Jan 1, 2006

By Lyman File

This paper discusses the overall challenges to construct a two-lane highway tunnel located in southwestern Colorado on U.S. Highway 160 for the Colorado Department of Transportation by the Kiewit Western Company. The purpose of this project is to provide the excavation and temporary support for a highway tunnel 280 m (916 feet) long. The tunnel cross section is 14.3 m (47 feet) wide by 8.5 m (28 feet) high, 105 m2 (1,130 SF).Construction methods include conventional drill and blast excavation with rockbolt and shotcrete ground support. This unique tunnel is being constructed under alpine tunnelling conditions and in the immediate vicinity of active highway traffic.

Jan 1, 2003

By John Duff Erickson

Computer use has become an integral part of mine planning at Kennecott Copper Corporation?s Utah Copper Division, Bingham Canyon mine. Engineers are using the computer for development drilling calculations, mineralization grade interpolations, ore value summaries, long-range mining plans and short- range mining plans. The versatility of the computer has made it possible to explore many mining plan variations and to develop plans covering varying time intervals and production rates. This paper will summarize computer use in long-range mine planning, tell how short-range mining plans are prepared by conventional methods and discuss the development and application of short-range mine planning by computer.

Jan 1, 1966

By A. Redman

Aquatic organisms are sensitive to free cyanide (HCN) though the presence of certain metals that can form stable complexes and thereby reducing both the amount of bioavailable cyanide. Recent work has suggested that consideration of HCN rather than total cyanide can provide the basis for water quality criteria. Cyanide is often present in complex effluents that affect speciation and bioavailability. We have developed a model to predict the speciation of cyanide in complex effluents and have shown that this model can predict the toxicity of metal-cyanide complexes in terms of HCN. This study evaluated available cyanide toxicity exposures with this model to assess the role of water chemistry (e.g., metal-cyanide interactions) on the observed. Toxicity endpoints based on total cyanide ranged over several orders of magnitude for a variety of metal-cyanide mixtures. However, predicted HCN concentrations among these same tests described the observed toxicity data to within a factor of 2. Aquatic toxicity can be well described using HCN though in certain metal-cyanide mixtures toxicity was jointly described by HCN and elevated levels of bioavailable metals. This work was performed in support of an industry-sponsored reassessment (Gensemer et al 2006) of the U.S. EPA water quality criteria for cyanide (EPA 1985) using free cyanide as the basis for the re-calculation. The work presented in this manuscript presents technical support for using free cyanide as the preferred basis for this recalculation.

Jan 1, 2011

By Edward B. Westphal

One of the purest gypsum deposits in the United States is located in northwest Oklahoma about 90 miles northwest of Oklahoma City. Gypsum beds of the Blaine Formation (Permian) are each 10 to 15 feet thick and 97 to 99 percent pure; they are being quarried by four companies in the area. Most of the stone mined by U.S. Gypsum Company is calcined for the manufacturing of wallboard and special plasters, but some of the crude gypsum is marketed for cement manufacture and for use as soil conditioner. Reclamation of the mined lands at Southard, Oklahoma, has been carried out since 1968, and the company is now involved in a cooperative program of land revegetation to aid in erosion control, provide for wildlife, and for beautification.

Jan 1, 1978

By Deepak Malhotra

Following a severe recession in the early 1980&apos;s, mining companies have taken significant steps to improve metallurgy and reduce operating costs. They do not view chemical reagents and the long-term relationship with reagent producers the same way they did two decades ago. This paper discusses the general perspective of changes that have taken place over the years, especially with respect to cost of production, selling price and environmental constraints. A cooperative program between the consumers and producers of chemical reagents is recommended to understand each other&apos;s problems and identify the present and future needs of the mining industry. This approach will be beneficial to the long-term survival of both parties.

Jan 1, 1994

By Ray Brainard

Charleston Water System?s Daniel Island Extension Tunnel, initially thought to be the simplest of the four replacement tunnels to design and build, became the most challenging after the discovery of an unexpected 30-ft thick lens of sand in the normally consistent Cooper Marl while sinking a shaft on Daniel Island. This paper will explore the challenges involved with determining the extent of the unforeseen lens of sand, the accelerated boring program, and the redesign of the vertical alignment?keeping the alignment between the sand layer and the bottom of the Cooper River. It will describe how the challenges were overcome, and how the Owner, Engineer, and Contractor were able to team together to achieve the desired results.

By J. D. Miller

Flotation chemists have long sought to unravel the mechanisms of carboxylate collector adsorption by semi-soluble salt minerals. In particular, the adsorption density of adsorbed carboxylates, adsorption kinetics, speciation (chemisorbed, physisorbed), orientation, and conformation are of interest. Given the importance of these phenomena in establishing the hydrophobic state at a mineral surface, in-situ surface spectroscopy studies certainly are justified. Such measurements traditionally have been difficult to perform. However, beginning in the late 1980s, a Fourier transform infrared (FTIR) spectroscopic technique was developed that has allowed for the acquisition of a wealth of detailed information concerning carboxyiate adsorption in semi-soluble salt flotation systems. The technique, internal rejection spectroscopy using single-crystal internal reflection elements, is reviewed, as it applies to semi-soluble salt flotation systems.

Jan 1, 1999

By Victor J. Scaravilli

This report is based on experience developed on the construction of one contract for the Buffalo, New York subway. The Buffalo subway is under construction for the Niagara Frontier Transportation Authority and is called the LRRT-Light Rail Rapid Transit or more commonly the Metro. The Initial Route of the Buffalo subway construction started early in 1979 and is scheduled for completion in May, 1984. The initial system includes 5.2 miles of underground construction, 1.3 miles at grade for a total of 6.5 miles of subway system. A total of fourteen stations, eight underground and six at grade are included on the system. The Initial Route has a planned expansion to 17.3 miles in the future. On January 15, 1979, a Joint Venture of S & M Constructors, Inc., Solon, Ohio, James McHugh Construction Co., Chicago, Illinois, and Kenny Construction Company, Wheeling, Illinois, was awarded contract 100031, the Line Tunnels from Amherst Street to South Campus in northcentral Buffalo between Delaware Park and the State University, (see Fig. 1, Location Plan) This $35,000,000.00 contract was designed by Hatch Associates Consultants, Inc., Buffalo, N.Y. The Notice to Proceed was issued January 15, 1979 and the scheduled completion date is August 18, 1981. The project consists of two parallel rock tunnels with a minimum excavated diam of 18 ft 0 in. and a final concrete lining of 16 ft 0 in. diam. The tunnels total 14,630 linear ft. In addition to the tunnels, contract C-31 includes four shafts, an underground pump station, three cross passage connections, and other minor work items. (see Fig. 2, C-31 Project Plan and Profile) The tunnels were constructed primarily within the Bertie Formation, an approximately 50 foot thick moderately fractured to massive, dolo-

Jan 1, 1981