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By S Paciornik

Computer-controlled microscopes with digital image acquisition and analysis led to the creation of the new field of digital microscopy. These techniques not only allow a certain degree of automation but have also brought new possibilities to microstructural characterisation. One of these new and promising possibilities is co-site microscopy, which links different kinds of information obtained from different microscopy techniques. The present work presents the development and implementation of a co-site microscopy methodology that combines images obtained by reflected light microscopy (RLM) and scanning electron microscopy (SEM). This methodology can improve the SEM analytical capacity by adding colour information from RLM. It involves the whole sequence, from image acquisition at the microscopes to the analysis of the phases using pattern recognition techniques. An automatic registration procedure for the two kinds of images was developed, allowing the adjustment of magnification, translation, rotation and pixel size, and the correction of local distortions. Thus, the images from RLM and SEM can be combined to build a multidimensional data set of each field, which can then be used in a pattern recognition approach to discriminate different phases. The methodology was tested with a copper ore sample, aiming at the discrimination of minerals that are not distinguishable with either RLM or SEM.

Jan 1, 2008

By Samer Sadek, Brian Hagan

We are thrilled to welcome you to the 2025 Rapid Excavation and Tunneling Conference (RETC), which will be held in Dallas, TX. This year’s conference will showcase the continued trend of strong industry interest, as there will be a record setting 115 papers being presented over the course of three days. The set of papers compiled in this book captures the latest and greatest information on a broad array of topics within our fascinating tunneling industry. We hope that the compilation of selected papers in this book will provide a comprehensive recap of the conference while also providing a source of future reference for contractors, engineers, and anyone in general who is a student of our beloved and unique industry. Since its inception in 1972, RETC has been the preeminent tunneling forum to promote ideas, tell stories, share lessons learned, and promote new technologies. RETC prides itself on its focus towards highlighting real-world experiences and practical ideas, with the intent to help the entire industry learn from one another and grow. The need for us all to stay sharp and remain on the cutting edge of technology has never been stronger – the technology and ideas that have been applied in aerospace are now attempting to mix with tunneling, and the advancement of AI continues to permeate all industries. However, no amount of technology or AI can fully replace the human element, and in our tunneling industry, the human element is key and is what sets us apart. In tunneling, every project is different, because the ground is always different. We can only take what the ground will give us, and we must rely on our past experiences to get through present day challenges. Most importantly, we must rely on each other. This is the heart of what RETC is all about. For those of you attending this conference, we encourage you to attend as many sessions as possible and engage with your colleagues to discuss during the breaks in between sessions. This sharing of ideas is what keeps us connected and helps to expand our industry. Please also try to engage with the scholarship students and the newcomers who will be in attendance, as it is the new ideas and fresh energy from the next generation that will continue to make our industry thrive into the future. The program chairs thank and greatly appreciate the efforts made by our session chairs, co-chairs, authors, the members of the RETC Executive Committee, and most importantly the SME staff towards making this RETC possible.

Oct 1, 2025

By Others, C. M. Weld

During the past two years the Bureau of Mines has issued a series of mimeographed reports giving the results of research work and experiments conducted as part of its war minerals investigations. In this bulletin the reports on manganese are presented, which range in scope from the beneficiation of the ore to the utilization of the metal. The bulletin is in eleven chapters, each comprising a separate report, arranged in the order given below. 1. General information regarding manganese, by C. M. Weld. 2. Uses of manganese other than in steel making, by W. C. Phalen. 3. Problems involved in the concentration and utilization of domestic low-grade manganese ores, by Edmund Newton. 4. Preparation of manganese ore, by W. R. Crane. 5. Leaching of manganese ores with sulphur dioxide, by C. E. Van Barneveld. 6. The Jones process for concentrating manganese ores; results of laboratory investigations, by Peter Christianson and W. H. Hunter. 7. Cost of producing ferromanganese ores, by C. M. Weld and W. R. Crane. 8. Production of manganese alloys in the blast furnace, by P. H. Royster. 9. National importance of allocating low-ash coke to the man- ganese-alloy furnaces, by P. H. Royster. 10. Electric smelting of domestic manganese ores, by H. W. Gillett and C. E. Williams. 11. Use of manganese alloys in open-hearth steel practice, by Samuel L. Hoyt. As each chapter was originally prepared as a unit, there is neces- sarily some duplication and overlapping. With certain exceptions, however, each paper is reproduced in practically its original form. In chapter 1, covering certain general phases of the industry, such as uses, specifications, prices, and statistics, the subject matter has been somewhat modified in view of changes in conditions.About 95 per cent of the manganese consumed in the United States goes into the manufacture of steel. The remaining 5 per cent is used in a number of minor industries, the chief of which is the manufacture of dry cells. These minor uses are described in chapter 2. No discussion of the geology of manganese eres is presented, but a short bibliography on the subject is appended. With few excep- tions the manganese deposits of the United States are irregular, pockety, and uncertain. Largely for this reason, mining methods are crude and hardly warrant descriptions. The concentration of manganese ores, however, is an important problem and involves some details not common to other ores. Chapter 3 discusses the concentration and utilization of low-grade ones, notes the relationship of concentration to metallurgical prao- tices, outlines concentrating processes, and treats of commercial problems. In general, as regards concentration methods, manganese ores may be divided into two groups, as follows: (1) Ores permitting mechanical separation of the manganese minerals and the gangue, and (2) ores in which the manganese minerals and the gangues are so intimately associated that separation requires some hydrometal- lurgical or pyrometallurgical process. Heretofore, attention has been confined almost wholly to mechanical separation, chiefly by gravity. In fact, so far as known, all production of concentrates has been by wet gravity methods, although during the war some companies investigated the commercial pessibilities of magnetic separation and reported favorable results, the construction of one magnetic con- centration mill being started. The usual wet gravity methods are described in chapter 4. During the war, the Bureau of Mines undertook investigations of methods applicable to ores of group 2. A hydrometallurgical process involving leaching with sulphur dioxide was studied at the mining experiment station of the bureau at Tucson, Ariz. The results of this work, presented in chapter 5, indicate that the process is metallurgically feasible but the cost makes it unattractive. The results of an investigation of a pyrometallurgical process known as the Jones process are presented in chapter 6. The process, which is still in the experimental stage, was found to be metal- lurgically sound. The manganese product is not a concentrate but an alloy, made directly from a lean unconcentrated ore. The custom- ary method is to manufacture alloys from high-grade ores or from concentrates of leaner ores. A discussion of the costs of ferro-grade manganese ores is pre- sented in chapter 7. This discussion is in general terms only, but should be of use in so far as it relates to competitive conditions.

Jan 1, 1920

By G. O. Allard, A. Gobeil

The Chibougamau area is the eastern segment of the MatagamiChibougamau greenstone belt. The Archean rocks of the area consist of two mafic-to-felsic volcanic cycles ( Roy Group) overlain by a sedimentary-volcanic sequence (Opemisca Group). The Roy Group volcanics are intruded by many coeval and comagmatic differentiated gab bro sills. The Supracrustal rocks of the Roy Group and Opemisca Group have been folded about north-south axes, refolded isoclinally about east-trending axes and metamorphosed to the greenschist facies. The same lithologies have been identified east of the Grenville Front at amphibolite grade. The first volcanic cycle consists of 3000 metres of porphyritic pillowed basalts and comagmatic gabbro sills (0batogamau Formation) overlain by a thin sequence of felsic pyroclastics, porphyritic dacites, and iron formation (Waconichi Formation). The Dore Lake Complex is a sill-like layered complex intruded in the upper part of the Waconichi Formation. The second cycle consists of 3600 metres of pillowed basalts and gabbro sills (Gilman Formation) overlain by a volcanosedimentary assemblage less than 1000 metres thick (Blondeau Formation). The Cummings Complex consists of the Roberge sill (dunite and peridotite) at the base, the Ventures sill (gabbro) and the Bourbeau sill (leucogabbro and quartz ferrodiorite) at the top. It is emplaced within the Blondeau Formation. The Opemisca Group sediments and minor porphyritic K-rich andesites (Stella, Hauy, and Chebistuan Formations) form narrow belts preserved in the synclines of the area. The Proterozoic rocks of the Chibougamau area consist of conglomerates, arkoses, and argillites with dropstones of the Chibougamau Formation. North of Chibougamau, the Mistassini Basin forms an elongate northeast-trending basin filled with sediments of the Mistassini Group. Conglomerates, sandstones, argillites, dolomites, stromatolitic dolomites, and iron formation are the principal sediments within the basin.

Jan 1, 1984

By Edward E. Johnson

The U.S. economy made significant progress in 1984. The current-dollar gross national product (GNP), the market value of the Nation's output of goods and services, increased almost 11 percent over that of 1983 to slightly more than $3.66 trillion (table 1), and the real gross national product increased almost 7 percent.2/ Such rapid growth in real GNP has not occurred since the early 1950's. Real final sales increased only 5 percent during 1984, and real business inventories increased $24.8 billion ($57.9 billion in current dollars). Total employment of 106.7 million was an all-time record, and the unemployment rate declined from 9.5 percent in 1983 to 7.4 percent in 1984. During 1984 the U.S. dollar showed great strength on international markets, contributing to large current-dollar negative net exports of goods and services (-$62.5 billion) and even larger negative net exports of merchandise (-$107.6 billion). The strong dollar and the substantial increase in net imports of goods and services helped reduce U.S. inflationary pressures and provided a major source of loanable funds for financing domestic private investment.

Jan 1, 1985

By Milton H. Fies

To present some idea as to how the Bureau of Mines may most effectively serve mining, it is necessary that we make some resume of its pact accomplishments in order to determine what, if any, changes will be of greatest service to the industry and to the nation. There are a great many times in life when one begins to wonder whether or not Emerson, in his famous epigram about "mousetraps" and "beaten paths" and "final recognition of intrinsic worth", took into account the item of time. The intrinsic value of any movement, of any work, of any accomplishment will ultimately be recognized, of that there is no doubt, but may a man in history has gone to his end in martyrdom because the world was slow in the acknowledgement of the true excellence of his worth, and this is likewise true of institutions.

Jan 1, 1934

By AIME AIME

THE American Engineering Council, which is the working body of The Federated American Engineering Societies, held its first meeting in Washington, Nov. 18 and 19, 1920. The Federated American Engineering Societies was formed in Washington in June and is composed of engineering and technical societies, national, state, local and regional. These Member Societies elect delegates to the American Engineering Council, which is the administrative body of the Federated. The meeting was called to order by Richard L. Humphrey, Chairman of the Joint Conference Com¬mittee, and the program (which is printed below) was carried out without substantial change by E. S. Carman, who was elected temporary chairman. Under the Constitution, the Council appoints an Executive Board, the members of which are chosen according to the proportional membership of the vari¬ous Member Societies in their respective districts. Under this plan, with the present membership, 'the national societies will have 14 members and the local societies 6 members on the Executive Board.

Jan 1, 1920

By G. R. Hopkins

According to the annual refinery-capacity survey of the Bureau of Mines, the number of refineries in the United States showed little change in 1940, increasing from 057 the first of the year to 562 at the close. Although a number of plants were dismantled in Texas and other States, more than compensating gains were made in California, Illinois, and other States. Low gasoline prices, competition for crude-oil supplies, particularly in Illinois, and the termination of a favorable distributing arrangement for independent plants in the Los Angeles area, forced about 50 refineries to close down in 1940. The number of operating plants accordingly declined from 461 on January 1, 1940 to 420 on January 1, 1941 and the number of idle plants increased from 86 to 136 in the same period. These developments were also reflected in the capacity data, the operating capacity declining from 4,196,694 barrels daily on January 1, 1940 to 4,180,588 daily on January I, 1941 and the idle capacity rising from 431,952 barrels to 53g8381 barrels in the same period. However, the completed capacity on January 1, 1941 (4,718,969 barrels daily) was 2 percent above the previous year.

Jan 1, 1941

Workers at Anaconda Aluminum Company's primary aluminum smelter at Sebree, Ky., were back on the job December 1, after agreeing to a new 3-year contract. The old contract had expired November 15. On December 20, the Aluminum Company of America reportedly shut down a 42,000-ton-per-year potline at its Wenatchee, Wash., primary aluminum smelter and half of a 23,000-ton-per-year potline at its Vancouver, Wash., smelter as a result of a power cutback by the Bonneville Power Administration. A1 so in December, Kaiser Aluminum & Chemical Corp. reduced overall power at its Mead and Tacoma, Mash,, smelters and shut down one of eight 27,500-ton-per-year potlines at Mead. Reported shutdowns for the firms since September have amounted to 76,000 tons for Alcoa and 50,000 tons for Kaiser. Alcan Aluminum Ltd. announced plans to double the generating capacity at its Kemano hydroelectric power plant in British Columbia to 1,916 megawatts. The additional power would be equal to that required of a primary aluminum smelter with an annual capacity of 567,000 tons.

Jan 1, 1980

By A N. Danoucaras, S E. Goater, D Hearne, A M. Bansuan

It is globally recognised that existing and emerging mining activities should be conducted in a æsustainableÆ manner for the entire life of mine. Many companies annually publish corporate sustainability reports to demonstrate their actions in accordance with international expectations. This concept of sustainable mining practices also applies to mine water management, with influences often extending beyond site operations, affecting surrounding catchments and community users. This paper explores differences in conceptual and operational terms of æsustainableÆ mine water management within the Philippines. Outcomes of a review of corporate sustainability reports, governance documentation, research programs, and stakeholder knowledge acquired through action-research workshops are presented. The paper aims to inform and support future capacity building exercises delivered by the International Mining for Development Centre (IM4DC), with outcomes tailored to government officials and policy makers of developing countries. The project is funded by IM4DC, which is working with AusAID to identify needs and develop capacity with regard to mining for development; specifically, issues pertaining to governance and regulation, social and environmental sustainability, and operational effectiveness in developing countries.CITATION:Bansuan, A M, Goater, S E, Danoucaras, A N and Hearne, D, 2012. Integrated sustainable water management in mining for development in the Philippines, in Proceedings International Mine Management 2012, pp 205-226 (The Australasian Institute of Mining and Metallurgy: Melbourne).

Nov 20, 2012

By L. D. Schmidt, W. C. Schroeder, A. C. Fieldner

"INTRODUCTION The highly mechanized character of modern warfare makes steel the most vital raw material. The shortage of steel scrap in the United States is forcing the use of increased quantities of pig iron in steel manufacture, so that the rate of pig-iron output will continue to be the controlling factor in steel production. 5/ At the same time, the construction of new blast furnaces is limited both by time and the amount of strategic material available. Under such circumstances, every effort must be made to attain and then maintain maximum pig-iron output from the equipment now in use.When forcing a blast furnace to the ultimate in production the highest standards for quality and uniformity of the coke must be maintained. In view of these facts, the Bureau of Mines, in cooperation with the Office of the Solid Fuels Coordinator for War, is surveying the coke industry to study the various steps in producing coke of higher quality and greater uniformity. 6/ The engineers conducting the survey are visiting key men in coke-oven and blast-furnace organizations to determine, first, the major and most common problems in coke production and use; and, second, the best and quickest method for solving them. Various operators have made good progress in solving individual problems, and a Nation-wide exchange of information among them will make possible widespread adoption of the best practices. It is the purpose, of the survey and reports such as this preliminary one to facilitate such exchange of information. As an outgrowth of the survey, it was soon revealed that many operators could be helped by cooperation with various Government agencies, particularly to procure suitable coals, minor additions to equipment facilities, and tests on certain properties of coal or coke, or specific advice concerning the operation of various types of equipment. The machinery and organization necessary for securing this cooperation have been set up as a part of this work."

May 1, 1943

By César Bernal M

El presente trabajo busca establecer el mejor plan de explotación de la mina Cobriza a través del nuevo proyecto de expansión. El plan de explotación señala que los ciclos de explotación, el número de tajeos requeridos por el método de corte y relleno, la selección del equipo de mina, así como los servicios auxiliares para suministrar el tonelaje necesario de mineral a la nueva planta de Coris.

Nov 8, 1982

By Katherine A. Klein

Refuge chambers may potentially save the lives of miners during a mine emergency. For this reason, it is crucial that miners know how to operate them. Unfortunately, because refuge chambers provide so many services, they can be very complicated and difficult to operate. Therefore, NIOSH has created this document with suggestions for developing manuals and educational materials. A multidisciplinary team comprised of NIOSH engineers, sociologists, psychologists, health communication professionals, and geologists developed the recommendations contained in this document. These recommendations are based on an evaluation of manufacturers? instruction manuals from both the U.S. and globally, interviews with over 20 mining and safety experts, and an extensive literature review. This research, focused on the best practices for refuge chambers, led to the formulation of this document. It is intended to offer suggestions to manufacturers and mine operators on how to create effective and easy-to-understand training manuals for miners as well as tips to create the most comfortable and usable refuge chambers. It should be noted that these recommendations are not meant to substitute for manufacturer-supplied materials but rather to be used in conjunction with manufacturer?s materials. Manufacturers should always be consulted for up-to-date information about their chamber. Although different states and different mines refer to underground refuges by different names, this guide will simply refer to underground refuges nearest to the face as refuge chambers, whether inflatable from a skid or constructed from steel. Other popular terms for refuge chambers are rescue chambers, rescue shelters, and refuge shelters. Refuges that are nearer to the shaft, whether a prefabricated refuge chamber or one built into a crosscut, will be referred to as outby refuges because of their location in the mine. Outby refuges can be permanent, semipermanent, or portable and are usually located at every other SCSR cache. Outby refuges are sometimes called hardened rooms, outby shelters, and in-place shelters. When discussing outby refuges and refuge chambers collectively, this guide will refer to them as underground refuges. Other terms for underground refuges include refuge alternatives, locations of safety, and safe havens. This document is designed to be read either cover to cover or by specific section. It is recommended that on first read, this guide be read cover to cover. In subsequent readings, manufacturers and mine operators may find it easier to use the table of contents page to locate specific information on parts of the refuge chamber.

Jan 1, 2009

As shown in Table 9, consumption has risen steadily for the period November through April, reaching its highest level since June of 1974. Imports remained at a relatively high level in spite of decreased imports from Zaire and Belgium-Luxembourg. Award prices for cobalt sold by the General Services Administration on June 17, 1976 ranged from $5.058 to $5.41211 per pound of contained cobalt. The high bid was about $1 per pound above the current market price set by the major sales agent in the U.S. for cobalt on April 15, 1976. COPPER: Eight domestic producers on July 1 hiked refined copper prices by 4¢ to 74¢ per pound for cathode and to 74.625¢ for electrolytic wirebar. New York Commodity Exchange (COMEX) June pricing of prompt contracted copper averaged 70.6¢, with daily quotes registering between 67¢ and 72.5¢ per pound. In June, London Metal Exchange (LME) cash wirebar prices averaged 70.3¢, trading between a low of 65.5¢ and a high of 73.6¢. End of the month copper stocks totaled 108,758 short tons for the COMEX and 539,350 metric tons for the LME.

Jan 1, 1976

By William J. Douglas

This document describes the development of a conventional mining equipment data base, and an approach for conducting industrial engineering studies of arbitrary mining systems employing network techniques. Data was acquired through underground time studies. Each member of a four-man field team was assigned to a specific machine during each shift for which observations were conducted. Using digital wrist watches and networks describing the man-machine interactions, all events occurring luring the course of each shift were recorded on cassette tapes. The tapes were transcribed, coded, keypunched, and validated using computerized editing techniques. The resulting data files were processed to provide statistics relating to activity durations and event frequencies. The results were used to evaluate operator, machine, and system performance for each section which was observed. Equipment, reliability, and maintainability analyses were conducted using the industrial engineering data files in conjunction with historical information collected at the mine site.

Jan 1, 1976

By J. C. Reid

Pre-cambrian scheelite deposits in Northeastern Brazil are widespread in a high grade metamorphic terrain. Previously these deposits had been interpreted as contact-metasomatic. In this paper, a volcanigenic model is invoked based on the volcanic setting (proximal to distal) and the absence of associated felsic intrusives and spatially associated metasomatic skarns. The tungsten was introduced into sediments by volcanic- exhalative processes and subsequently remobilized and further concentrated by heat and metamorphis fluids associated with high-grade metamorphism and migmitization. An alternative syngenetic - diagenetic model is discussed which requires the transport of tungsten by heteropoly acids and deposition of the tungsten as a function of Eh and Ph conditions and different clastic depositional environments. While such stratabound tungsten deposits are considered rare in North America, the hypotheses developed in this paper may open new areas for exploration.

Jan 1, 1983

By Timothy A. Clancy

To help reduce the Nation's dependence on imported chromite, the Bureau of Mines is conducting research on the use of dolomites as an alternate material. Dolomite is a plentiful domestic resource and offers certain advantages as a refractory raw material. A review of the literature has indicated that there are many sources of high-purity dolomite in this country and that European nations use a greater proportion of dolomite refractories, primarily in steelmaking, than the United States, The Bureau of Mines characterized 14 domestic dolomites as to chemistry, density, mineralogy, microstructure, and thermal behavior, to develop baseline data on their suitability as refractory raw materials.

Jan 1, 1983

By Milford L. Skow

MICA is a group name for a number of complex hydrous aluminum silicate minerals that have a sheet or platy structure and extremely variable and complex compositions containing various metallic ions, particularly those from the alkali group. Muscovite and phlogopite, the two varieties of significant commercial value, are the principal consideration of this report; muscovite has major importance industrially. The mica crystal, because of its laminated structure, can be split easily and accurately into thin films that are transparent, flexible, elastic, tough, and waterproof and have outstanding dielectric and insulating characteristics. This combination of properties is not duplicated in any other known substance. The world production of mica can be divided into two main classifications: (1) Sheet mica and (2) scrap mica (including flake mica). In general, separate divisions of the industry produce these two classes of mica, which differ widely in their uses and in the forms in which they are marketed. A glossary of mica terminology is given in appendix A.

Jan 1, 1962

By C Roche, G M. Mudd

The Morobe Province of central Papua New Guinea (PNG) has been mined for gold for nearly a century, although it is only in the past decade that large-scale modern mining commenced. The Hidden Valley gold-silver project began construction in mid-2006 and production by August 2009, and is located in the mountains above Wau in the headwaters of the Watut River. The mine is owned and operated by the Morobe Mining Joint Venture (MMJV), which also owns the Wafi-Golpu project, comprising the Wafi gold deposit and Golpu copper-gold deposit, situated in the Watut River Valley. Together they represent a potential mine of the scale of Ok Tedi or Bougainville or bigger. The MMJV is owned in equal shares by Newcrest Mining from Australia and Harmony Gold from South Africa. Although Hidden Valley was the first large-scale mine in PNG to engineer and build a tailings storage facility, poor environmental management during construction and early operations led to significant erosion of waste rock and sedimentation impacts throughout the ~200 km length of the Watut River. Since then, substantial efforts have been made to improve environmental management, especially waste rock placement and storage and water quality management. While the impacts from the Hidden Valley project appear to be reducing, the saga has heightened concerns by many along the Watut River and across PNG about ongoing impacts from mining.This paper presents the results of an ongoing project in the Morobe Province conducted by the Mineral Policy Institute examining the historical, current and future impacts of mining, including community views, social and environmental impacts and the monitoring and regulation of mining. Overall, there is a clear need to more fully integrate social and environmental issues into life-of-mine planning and go above and beyond regulatory requirements. In this way, some of the lessons learnt – by the community, MMJV and government – can be incorporated before, during and long after mining.CITATION:Mudd, G M and Roche, C, ?2014. Mining in Morobe, Papua New Guinea – impacts, assurance and self-determination, in Proceedings Life-of-Mine 2014 , pp 313–336 (The Australasian Institute of Mining and Metallurgy: Melbourne).

Jul 16, 2014

By George F. Kunz

Jan 1, 1902