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By Harvey Parker

The International Tunnelling and Under-ground Space Association (ITA) is a nonprofit organization that represents all aspects of the tunneling and underground space industry worldwide. The United States has had a prominent role in ITA since its 1974 inception. ITA was formed as a result of a worldwide survey conducted in the early 1970s by the Organization for Economic Cooperation and Development (OECD). Bill Lucke was in charge of tunnels for the U.S. Federal Railroad Administration and was a member of the organizing committee that created ITA. He became a vice president of ITA. Jack Lemley served as President of ITA from 1983 to 1986. Dick Robbins was very active in ITA and served for many years both as a member of the Executive Council and as First Vice President. Harvey Parker has served as President of ITA for the last three years and will serve as Past President for the next three years. Moreover, there are many individuals and companies from the United States that have contributed significantly to the activities and the success of ITA. There have been several active Working Group Animateurs from the U.S. and there have been significant contributions from many individuals as well as companies from the U.S. Several engineers from the U.S. are currently serving ITA in a leadership role. The Underground Construction Association of SME (UCA of SME) is the official organization representing the U.S.. SME Executive. [ ] Director Dave Kanagy and UCA President Tom Peyton were instrumental in the U.S.?s role at ITA during the last few years. Peyton has been the official delegate to ITA. Henry Russell and Christian Ingerslev are both Animateurs of ITA working groups. This article will introduce ITA and its activities. A subsequent article will describe the ITA in more detail and will discuss the significant role the U.S. has played in the development and success of ITA.

Jan 1, 2007

By Enrique Hermana, Raymond F. Dalton, Raymond Price, Barry Hoffman

Introduction Chloride leaching of sulfidic ores has been known about for 100 years. It is recognized as a highly efficient process to produce concentrated leach solutions. Despite this, chloride leaching found little practical application until recently because of the highly corrosive nature of concentrated chloride solutions. This situation changed with the advent of modern construction materials such as GRP, polypropylene, butyl rubber, etc. And in the past 20 years, research has burgeoned in the area of chloride hydrometallurgy. The research impetus stemmed from the belief that chloride leaching can provide an alternative to smelters for treating conventional copper concentrates. In addition, chloride leaching was thought to be suitable for on-site refining of copper at small tonnage operations located in remote areas. And chloride leaching was seen as a logical choice for treating unusual or complex concentrates that smelters could not handle. Underpinning these beliefs is the attraction of chloride-based hydrometallurgical processes for sulfidic ores. Sulfur is liberated in the environmentally acceptable elemental form rather than as sulfur dioxide. Consequently, sulfidic copper ores have received much attention. A review of Edmiston in 1984 describes 12 chloride-based processes. All managed to progress past the "laboratory beaker" stage of evaluation. In nine of these processes, copper is recovered electrolytically. Key features of these processes are summarized in Table 1. Table 1 shows that the processes must include a copper solvent-extraction step. Only these processes produce a clean copper electrolyte capable, with no further refining, of directly producing high quality cathode copper. The ICI/Elkem process is the exception here. The rest of these processes use o-hydroxyaryloxime reagents for the solvent extraction of copper and are constrained by the performance of these reagents. This is governed by hydrogen ion concentration (Equation 1). The practical result is that only relatively dilute copper solutions can be treated (Canmet, Phelps Dodge), or careful pH control or adjustment is necessary (Minimet Recherche, B.H.A.S.). This negates one of the attractive features of chloride leaching - its ability to produce very concentrated copper solutions, up to 40-45 gl-1. [ ] In all four processes using o¬hydroxyaryloxime extractants, solvent extraction transfers the copper from the chloride to the sulfate medium. To minimize cross-contamination of the two anions, the loaded organic solvent has to be scrubbed to remove the chloride ion. This represents an additional complication in the solvent extraction circuit. And it

Jan 1, 1988

By R. A. Reiley

Introduction Democratic countries are founded on the principle that all citizens have the right to participate in policy setting and decision-making processes. Citizen participation is especially evident in environmental issues and policies. In the United States, there are currently over 10,000 environmental organizations and new ones are being formed each year. Many of these organizations are formed on a watershed basis and are particularly concerned about the impact mining has on the environment. While the environmental issues vary from area to area, most concerns center around mining impacts related to subsidence, water pollution, and water diversion. Citizens have a number of avenues for participating in lawmaking that affects the mining industry. Some of these avenues include participation in litigation and citizen ballot initiatives. In addition, there are less formal methods of participation that include attending public meetings, commenting on agency rules or lobbying on specific legislation. The intent of this article is outline the various public participations mechanisms, highlight the latest legal developments that have affected mining industry through citizen participation, and briefly discuss emerging issues.

Jan 1, 2001

By Steve Kral

Conference themes are usually chosen by organizers to reflect the current state of the industry. The Colorado Section MPD came up with what may be the most appropriate theme of a mining conference during the last few years. The local SME MPD section’s theme of its 56th annual conference was “The Wild, Wild World of Mining.” The current boom can be felt in all aspects of the industry, including exploration, mining, processing, sustainability, and economic and political issues. Each of the 25 speakers at the conference, held in Colorado Springs, CO, touched on how the boom has impacted each of those aspects. The meeting attracted about 110 people from around the world.

Jan 1, 2006

By Stanley M. Moos

In reviewing available vacuum filtration equipment in this paper, several types of filters have been included which are probably not familiar to operators in the mining industry. However, it was felt that these units might be of interest in the event that an application should arise for the filtration of a product in the future that does not exist today. In addition, exposure of our industry to equipment used in other industries might have a tendency to be thought provoking and perhaps lead to the development of equipment and/or applications in our industry which do not necessarily exist at this time. Most innovations in filtration equipment have been confined to the improvement or design change of components and accessories, particularly reflecting the availability of materials of construction that have been developed. Recent developments in the application of horizontal belt filters have been innovative. The application of this unit as a substitute for or an adjunct to thickeners in a CO circuit can certainly be innovative and perhaps provide a basis for reduction in capital and operating costs in this area. For example, mill tails are generally pumped at the highest possible density that will adequately flow. Tailings ponds and dams with their attendant design requirements are based upon this estimated water volume. Availability of a much dryer, non-flowing filter cake opens up several new options for disposal. Considerable cost savings could result in the design and planning of disposal areas for containing dryer material. . No attempt has been made in this paper to provide a manual for the operation of all of the many types of equipment that are available. Rather, the paper tries to present an overview.

Jan 1, 1978

By Manuel Gomez

This report presents prediction equations for eleven factors indicative of metallurgical coal quality which have been developed from data obtainable during exploration. Five coke strength parameters and six carbonization product yields have been predicted for coking coals having volatile matter contents in the range 16.3 to 42.1 percent, dry basis. The prediction models developed contain information from the proximate and ultimate analyses, the size consist, and the petrographic composition of coking coals carbonized in BM-AGA retorts at 800°, 900°, and 1,000°C. The equations reported have been evaluated with independent data derived from the 900°C carbonization of 33 binary blends. Present results show that metallurgical coal quality can be predicted ahead of mining. Capability to forecast coal quality is useful in mine planning and should provide basic information for optimization of blending and crushing techniques, leading to the production of uniform coke.

Jan 1, 1968

By Robert M. Matyas, P. E. Sperry, Robert J. Smith, A. A. Mathews

INTRODUCTION The first Dispute Review Board (DRB) was utilized on a tunnel project 20 years ago. Increasingly utilized on a wide range of construction projects, DRB's are becoming the norm on tunnel and underground projects. This paper summarizes the growth in this usage, uses observations and experience to establish that barriers to the utilization of DRB's are more perceived than real and that many arguments against the DRB concept are not valid, and notes some of the salient elements that should be considered in practice to optimize DRB effectiveness. The purpose of the paper is to provide an annotated checklist for current and prospective users. The basic concept, structure, and operation of DRB's are described elsewhere and will not be repeated here (ASCE, 1991). DISPUTE REVIEW BOARD USAGE A compilation of Dispute Review Board usage for tunnel and underground projects to January 1994 indicated use on 63 contracts with a cumulative construction value of $3.8 billion and a total of 60 disputes settled. As of that same date, DRB's were planned for another 63 contracts with an estimated construction value of $4.7 billion. (A listing of these 126 projects is available from the authors.) This success and popularity have spread to other civil projects as well as process and building construction. The increase in DRB usage has been exponential. See Figure 1.

Jan 1, 1995

By T. H. Eyde

Estimated natural zeolite production worldwide during 2004 remained at about 3.6 Mt (4 million st), about the same as in 2003. China continues to be the largest producer of natural zeolites followed by Cuba, Germany, Japan and South Korea. This may be changing, however. Since 1988, zeolite production from Australia, Indonesia, Malaysia, New Zealand, Philippines and Thailand has increased rapidly. Most of the production is consumed in aqua culture. Global demand for seafood has exceeded the ability of the oceans to supply it without over fishing. Zeolite minerals remove ammonia compounds from the ponds in which fish and shrimp are grown. It is estimated that, in Thailand and Indonesia more than 55,000 farms produce260 kt (286,500 st) of shrimp. Therefore, as shrimp production increases, so does zeolite consumption.

Jan 1, 2005

By Y. Wang, K. S. E. Forssberg, A. Johansson, X. Lu

This paper presents the desulphurisation of a fine graphite powder below 80 µm by high gradient magnetic separation. The removal of pyrite (FeS2) and pyrrhotite (Fe1-xS) from the fine graphite powder was carried out with a modified version of the Sala dry HGMS with vibration assistance. In addition, a comparative study with dry and wet HGMS systems has also been performed. In order to establish the performance of the desulphurisation, a test series of varying parameters such as magnetic induction, matrix type/configuration and vibration were performed. As an equipment/process for removing sulphurous impurities from the fine graphite powder, the dry HGMS is deemed useful and comparative with the wet HGMS.

Jan 1, 2002

By Verya Nasri, Agustin Rey

Once completed, the Montreal Réseau Express Métropolitain (REM) will be the fourth largest automated transportation system in the world. The REM represents construction costs of approximately 7.0 billion Canadian dollars. The project consists of 67 km of twin tracks over four branches connected to downtown Montreal. The project includes 26 stations with 3 underground stations in downtown Montreal. One of the underground stations was built using the NATM method with thin permanent shotcrete initial and final liners separated by a sprayed on waterproofing membrane. The 2 other underground stations were built with the cut and cover approach including one using permanent secant pile wall with permanent walers and struts as the support of excavation and the final perimeter wall of the station. The project also includes the rehabilitation and enlargement of the Mont Royal Tunnel. This 100-year-old double track tunnel is about 5 km long. The REM also consists of 3.6 km new TBM tunnel connecting downtown to the Montreal International Airport through saturated soft ground and karstic rock. By the time of RETC, the construction of REM underground structures will be completed. This paper presents the design and construction aspects of the underground structures of this mega project.

Jun 13, 2023

By G. C. Hall, B. E. Hobbs

Giant gold deposits are considered products of crustal-scale systems. Reduced fluids stored in mid to lower crustal reservoirs were discharged into mid to upper crustal sites of deposition. Elements of the architecture include crustal-scale structures, reduced packages of rock and regional seals. Gas-rich aqueous fluids were common but non-aqueous fluids may have been significant in the deeper parts of the systems. Fluid fluxes in over pressured domains were maintained by porosity waves. Abnormal heat input from the mantle may not be required once the systems were perturbed. Fluid-mixing and hypogene enrichment were probably the most significant precipitation processes.

Jan 1, 1999

By Ian Farmer, Nigel Glossop, Philip Garritty

Performance of tunnel boring machines - usually expressed in terms of penetration per revolution - is determined by relations between machine thrust and torque, head diameter and rock strength. It can be shown that for a given machine power and head diameter there is only one rock strength at which the machine performs optimally. In weaker rocks the available torque limits performance and in stronger rocks, the available thrust. Performance data shows that, historically, machines have been designed to cut weaker rocks. Optimization of thrust is required to improve performance in stronger rocks.

Jan 1, 1987

By Tim O’Neil

ISO 9000 is a system of quality standards that originated in Europe in the 1980s and has since been widely adopted by manufacturing companies throughout the world. The ISO 9000 standards have received less attention in the minerals industry. But, in part as a result of customer pressure, a trend is beginning to emerge for minerals producers to seek ISO certification. This is especially true among producers of industrial minerals. In early October 1994, SME's Industrial Minerals Division held a conference "ISO 9000 - uniting industrial mineral producers and consumers into quality partnerships," in Nashville, TN to bring people from the industry together to talk about their experiences with ISO 9000. William J. Miles, of Bentonite Corp. Inc., and A. Frank Alsobrook, of Alsobrook and Co., were cochairmen of the meeting. In his introductory remarks, Miles noted, "ISO 9000 is more than a quality program. It is a quality philosophy. Appropriately imple-mented, it is a contract between the supplier and the customer. It leads to continuous quality improvement and reduced manufacturing costs."

Jan 1, 1995

By C. K. Kocsis

A study was undertaken to evaluate the thermal environment and determine the contributing heat sources within the existing 153 Orebody of Coleman/McCreedy East Mine which would then enable the prediction of the climatic conditions in the mine?s future 170 Orebody. The study entailed continuously monitoring, for a 2-week period, the dry-bulb temperature, humidity and barometric pressure along the existing intake airways from surface down to the 4810 Level and throughout an active mining area on that level. Furthermore, the mining activities and associated equipment that could be responsible for any changes in the temperature and humidity conditions within this mining area were also monitored. These data were then used to develop and validate a climatic simulation of the mine?s mechanized cut and fill mining method. This climatic model was then transposed to the future 5700 Level in the deeper 170 Orebody, to determine the environmental conditions within its production workings and along the main haulage route ascending from that area. Based upon the simulations performed it was shown that the level of ventilation planned for the new orebody should be able to maintain adequate environmental conditions. However, this study did emphasize the importance of the appropriate distribution of airflow in workplaces that used auxiliary ventilation in order to sustain a suitable thermal environment.

Jan 1, 2009

By K. R. Long

Until it was defunded in 1995, the U.S. Bureau of Mines maintained a Cost Estimating System (CES) for prefeasibility-type economic evaluations of mineral deposits and estimating costs at producing and non-producing mines. This system had a significant role in mineral resource assessments to estimate costs of developing and operating known mineral deposits and predicted undiscovered deposits. For legal reasons, the U.S. Geological Survey cannot update and maintain CES. Instead, statistical tools are under development to estimate mining costs from basic properties of mineral deposits such as tonnage, grade, mineralogy, depth, strip ratio, distance from infrastructure, rock strength, and work index. The first step was to re-estimate ?Taylor?s Rule? which relates operating rate to available ore tonnage. The second step was to estimate statistical models of capital and operating costs for open pit porphyry copper mines with flotation concentrators. For a sample of 27 proposed porphyry copper projects, capital costs can be estimated from three variables: mineral processing rate, strip ratio, and distance from nearest railroad before mine construction began. Of all the variables tested, operating costs were found to be significantly correlated only with strip ratio.

Jan 1, 2011

By D. Malhotra

The economic viability of a mining operation depends on continuous process improvements. Diagnostic testing and plant auditing are essential useful tools to improve performance and reduce operating costs. Case studies are discussed to illustrate benefits of these techniques to improve plant efficiency.

Jan 1, 2001

By R. B. Krog

The use of belt air as an intake source at longwall operations has changed greatly over the past decades. The practical considerations for the use of belt air are controlled by a variety of factors, including airflow quantity and velocity, coal methane content, methane desorption rates, coal mining rate, belt length, stopping leakage and the number of gateroad entries. At longwall operations, the advantages and disadvantages of belt air are different than for gateroad development and longwall panel extraction. During gateroad development, the use of belt air to ventilate the working section will reduce the leakage from the intake to the belt compared to the belt air being ventilated outby the working sections because of lower pressure differentials. A greater quantity of airflow will reach the last open crosscut with the belt on intake than outby, given the same amount of pressure and airflow available at the mouth of the section. This paper will investigate the current ventilation practices regarding the use of belt air during gateroad development and longwall panel extraction. Operating considerations regarding air quantities and pressures to deliver the required airflow will be investigated using ventilation network modeling.

Jan 1, 2010

By T. I. Nelson

Natural aggregates, primarily stone, sand and gravel, are recovered from widespread, naturally occurring mineral deposits and processed for use primarily in the construction industry. They are mined, crushed, sorted by size, and sold either loose or in concrete products to build roads, houses, buildings, and other structures. Smaller quantities are used in agriculture, cement manufacture, and industries employing chemical and metallurgical processes. The growth of cities, their buildings and the highways that connect them have created demand for enormous quantities of aggregates. The aggregates industry is the largest mining industry in the United States in terms of production by weight, volume and by number of active operations.

Jan 1, 2005

Resolution Copper Mining LLC (RCML) is currently in a Pre-feasibility study evaluating a large and deep copper and molybdenum deposit in the historic mining district east of Superior, Arizona. Work scheduled for the next several years includes dewatering the existing shut-down mine (the Magma Mine) and sinking an exploratory shaft to 2,130 meters (7,000 feet) below the surface. To dewater the Magma Mine and sink the exploratory shaft, RCML must extract and manage about 2 billion gallons of accumulated mine water inventory, as well as about 300 million gallons per year of new inflow. In order to conserve a valuable water resource in a desert environment, RCML worked with the New Magma Irrigation and Drainage District (NMIDD) to provide treated mine water to blend with and supplement the NMIDD?s water supply to approximately 2,000 hectares (5,000 acres) of farmland located east of Phoenix. A 44 km (27-mile) pipeline was needed to convey the treated water. It was essential that a treatment system be used which could reliably meet irrigation water quality goals, produce a non-scaling effluent to maintain pipeline flow capacity, and generate a dense sludge minimizing disposal cost and volume. This paper describes the resulting mine water treatment and recovery system (MWTS) and how the system has performed against objectives.

Jan 1, 2011

By H. Mitri

A new monitoring device called SAFEBOLT (Stress And Force Evaluator in BOLTs) has been recently developed at McGill University. The device is essentially an alternative to the load cell, it permits the monitoring of bolt axial load in the field. The SAFEBOLT system consists of a portable readout unit, a connecting cable and the SAFEBOLT device, which is installed in the bolt head. The new device can be installed on any industry standard rockbolt or rebar. The device is completely encapsulated in the bolt head, which makes it resistant to corrosion, rugged, and free of any electric wires. Pilot tests at two underground Quebec mines were carried out and helped improve the initial design of the device head.

Jan 1, 2002