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By Girolamo Belardi, Silvia Serranti, Giuseppe Bonifazi, Roberta Palmieri

Ore textural and structural characterizations play a fundamental role in any preliminary study (i.e. comminution, classification, separation) addressed to the design and set up of beneficiation flow sheets. The possibility to utilise automatic tools able to perform a classification, and a quantitative description, of the mineralogical and petrographical characteristics of raw ore samples thus represents an important step to define, to control and to verify the entire set of parameters, ore-texture-related, that can affect the final beneficiation results. The procedure usually adopted is based on the analysis of polished sections and more in details the recognition of the different mineralogical species and associations and the measurements of some quantitative parameters estimating both the geometrical characteristics of each species and the possible spatial relationships between them. This approach, originally carried out by experts, utilising optical and/or electronic microscopy, was ‚replaced? during the years by more and more sophisticated devices integrating analytical facilities and acquired data processing. Such integrated analytical devices formed the breakthrough platforms into what is now known as modern Process Mineralogy. In this paper the possibilities offered by chemical imaging based devices and techniques, to perform ore minerals recognition/classification, and to perform their topological assessment, are presented. Tests have been carried out and are discussed in order to analyze the problems related to the development of suitable and low cost strategies addressed: i) to realize a full mapping of ore minerals/gangue inside selected samples, ii) to define the optimal data-flow handling to optimize the speed of processing versus the quality of the results and iii) to start to define logics and procedures finalized to implement innovative smart detection engines, chemical imaging based, for mineral processing addressed to perform both a preliminary characterization of the ore, at laboratory scale, and a further possible control of the different processed minerals flow streams.

Jan 1, 2014

By K. E. Robinson

Appendix A is an abridged extract of the report prepared by the Geotechnical and Structural Engineering Society of Idaho, and presents the results of their one-year study to evaluate the feasibility of disposing mill tailings by landfill construction. Appendix B describes the field and laboratory testing program completed by RDM to assess the effectiveness of a soil (slimes) liner as a means of seepage control to reduce the introduction of contaminants into the local ground water regime. Appendix C presents a summary of a thesis by Lawrence Martin on the analysis of the acid production potential of mill tailings, and the results of geotechnical testing of mill tailings completed by ROM. Appendix D describes potential landfill sites identified within the study area, the development of these sites to meet the present needs of the mining industry and the future requirements of the community is described. Appendix E summarizes the main legislation impacting on tailings disposal. Appendix F discusses the environmental and socio-economic factors that should be considered.

Jan 1, 1981

This Bureau of Mines report and its companion report (Information Circular 9142) have been prepared to assist in the preparation of prefeasibility type estimates for capital and operating costs of beneficiation of various types of mineral occurrences using current technology. The handbook provides a convenient costing procedure based on the summation of the costs for the unit processes required in any particular mining or mineral processing operation. The costing handbook consists of a series of costing sections, each corresponding to a specific mineral processing unit process. Contained within each section is the methodology to estimate either the capital or operating cost for that unit process. The unit process sections may be used to generate, in January 1984 dollars, costs through the use of either costing curves or formulae representing the prevailing technology. The mineral processing handbook includes individual cost estimation sections for unit operations associated with comminution, beneficiation, solid-liquid separation, hydrometallurgy, and special applications as well as infrastructure and plant general and administrative costs. When using this system for estimating cost data for a mineral processing facility or for checking or verifying processing costs from an existing facility, a minimum amount of background information is necessary.

Jan 1, 1987

By James S. Graham

Research at the University of Colorado on southern pine and Douglas-fir piling has determined that the existing building code design stress values of 1200 psi and 1250 psi, as determined by ASTM D-2899, are substantiated; but testing procedures should be revised. All full size piling tests should be standardized at 1/d ratios of 2:1, or confined tests performed. Also, it has been determined that theoretical design values for timber piling should not be based on the lumber criteria of D-245 and D-2555, but instead should follow the pattern set by engineers in the utility industry for timber poles, in accordance with ANSI 05.1.

Jan 1, 1986

By Ann G. Kim

Fires that occur in abandoned coal mines, waste banks, and in coal outcrops constitute a serious health, safety, and environmental hazard. Toxic fumes, the deterioration of air quality, and subsidence constitute the greatest hazards from these fires. Although tires on abandoned mined land (AML) occur in every coal-producing state, the severity of the problem varies. Methods to extinguish or control AML fires, including excavation, fire barriers, and sealing, are generally expensive and have a relatively low probability of success This U.S. Bureau of Mines report includes information from a variety of sources, i.e., agencies of the Federal Government, State agencies, research reports, conference proceedings, product information, and technical literature. This information has been collated into a comprehensive discussion of AML fire problems. Data on past fire control projects and on the estimated extent of the current problem have been compiled. Factors affecting the occurrence, propagation, and extinguishment of AML fires are discussed. Conventional fire control methods are described, and their probable effectiveness is evaluated. Information on the hazards of AML fires and safety considerations is included. The status of current technology, recent improvements in fire control methods, and areas of current research are discussed.

Jan 1, 1993

By John E. Rourke, O&apos

This report documents the process of site selection, instrument installation, data acquisition, and preliminary data analysis followed to characterize the physical response of overlying strata to longwall mining. A system of surface, subsurface and mine level instrumentation was installed at the Allen Mine in Weston, Colorado where the overburden varied in thickness from 600 to 900 feet. Survey monuments, automatic-recording strain-meters, multi-point rod extensometers, inclinometer-extensometers, stressmeters and tape extensometer convergence stations were installed to monitor displacements and stress changes. A preliminary analysis of the data acquired up until project termination has shown the system to be operative and strata response to be similar to that reported for other subsidence monitoring case histories. Recommendations for continued monitoring of the instrumentation systems are presented.

Jan 1, 1982

By George F. Bassett

"More will be expected from the mine or metallurgical plant electrical system in the late 70's and 80's in terms of energy conservation, reliability and fire prevention. Increased electrical loads 1•equired by larger arc furnaces, higher-horsepower motors for mine hoists and pollution control fans, and greater use of electrical heating will have to be supplied. Computers and sophisticated instruments will be used more extensively and have less tolerance for electrical fluctuations. More extensive control and monitoring systems will be required to increase production and minimize operating and maintenance costs. Changing energy costs will prompt design engineers to investigate in-plant generation, particularly where sites are remote from existing utilities lines or steam from turbines may be used in the process. Some utilities are requiring industries to increase their power factor to above 90% ; others are requiring stricter control of voltage flicker from arc furnaces and harmonics from rectifiers. There is a trend to AC with solid-state cont1•ols instead of DC for large cranes."

Jan 1, 1976

By Fred Leonard

This report is principally concerned with the engineering and economic feasibility of area surface coal mining systems other than draglines. This analysis evaluates shovel/ trucks, shovel/crusher/conveyors, and shovel/rail excavation and haulage systems for an assortment of geologic environments and production rates in the Powder River Basin (PRB) Shovel/trucks, front-end loaders/ trucks, and shovel/crusher/conveyors were studied in a multi-seam, dipping geologic area of the Four Corners Region. The Texas lignite engineering and economic research involved bucket-wheel excavators (BWE), BWE/backhoes, and scraper/backhoe combinations for overburden and coal excavation. The PRE truck/shovel study utilized the most recent computer simulation available in both the design and cost analyses. Detailed engineering analysis, followed by in-depth operating costs (operating and depreciation) result in a complete evaluation of each mining system. Cost comparisons of the different mining systems under similar geologic and production constraints are presented in the report to illustrate the estimated capital investment and production costs per ton of coal and bank cubic yard of overburden.

Jan 1, 1980

By Orlando Martino

This regional report covers the mineral industries of Canada and 40 countries and areas in Latin America and the Caribbean Basin. Also included is a brief description of the mineral potential of Antarctica. The Latin American region encompasses an area twice that of the United States. Latin America and Canada have a rich and diversified endowment of mineral fuels, metals, and industrial minerals. Tables 2 and 3 provide a summary view of the importance of Latin America and Canada's output of its major mineral commodities in world mineral supply in 1989 and 1990.

Jan 1, 1993

By L. W. Scott

This report presents an overview of explosionproof (X-P) enclosure research being conducted by the Bureau of Mines, This report emphasizes the increasing importance of research related to the safety con- siderations of X-P enclosures used in underground coal mines. Selected topics are included that summarize results of research in the areas of electrical clearances, reliability of enclosures with windows, safety factors in X-P enclosures, potting materials, performance tests for X-P enclosures, protection against high-voltage explosions, and innovative X-P devices.

Jan 1, 1985

By Joan Weinberg

Real output expanded at a 3.0% rate worldwide in 1987, a slightly lower pace than the 3.2% rate in 1986. The decline was accounted for largely by slower growth in the U.S.S.R. and the East European countries, as well as in the developing countries (table 1). According to the International Monetary Fund, output of industrial countries output grew 3.1% and rose most strongly in Japan, the United Kingdom, and Canada (table 2). U.S. economic growth remained at 2.9%, the same as in 1986. Consumer and government spending declined in industrial countries, while gross fixed investment: rent increased. This increase in fixed investment expenditures could be attributed partly to lagged results of some 1986 developments: the fall in oil prices, declining interest rates, and exchange rate changes. The U.S. budget deficit, as well as the large external deficits and surpluses among major industrial countries, hindered further growth .2 A report from the Organization for Economic Cooperation and Development (OECD) indicates that the impact of the October stock market crash was short-lived because it hit economies that were growing strongly, anyway.3 The growth of output in the developing countries slowed in 1987; however, output declined in the fuel-exporting developing countries. These countries have been adversely affected by weakness in oil prices and the depreciation of the U.S. dollar. The weighted average of inflation rates in industrial countries--as measured by the [ ] GNP deflator, was 2.9% in 1987, down from 3.4% in 1986. Prices rose 3.0% in the United States, up from 2.6% the previous year. Inflation for 1988 is expected to remain slightly higher in the United States than in Japan and the Federal Republic of Germany because of recent exchange rates changes and the elimination of slack productive capacity and labor in the U.S. economy. Prices in developing countries as a whole rose more than 10 percentage points in 1987. Higher import prices, caused by

Jan 1, 1988

By Oliver Bowles

PRICES of quartz sold in the United States in 1938 ranged from $1.15 to $36,000 a ton. This startling variation was due simply to the differences between glass sand and rock - crystal, materials that are virtually the same in composition. It illustrates the complexities in qualities, uses, and values of industrial minerals. It is generally stated that mineral deposits are exhaustible resources which can never be replaced when depleted. This statement is no longer true with respect to certain industrial minerals now recovered in increasing quantities from that most inexhaustible of all sources of supply, the ocean. Salt has long been obtained from sea water, particularly on the Pacific Coast, and reference was made a year ago to the large bromine recovery plant at Wilmington, N. C. Now the Westvaco Chlorine Products Corp. is operating a large plant at Newark, Calif., having a capacity sufficient to recover daily from the ocean raw materials that will produce 60 tons of various magnesium products. Lime is used to precipitate the magnesia from salt-water bittern. The products are chiefly magnesium carbonate for chemical uses, periclase and other refractories, and oxychloride cement for flooring.

Jan 1, 1939

By Lloyd A. Morley

This seven-chapter document is the first volume of a two-volume report that presents a comprehensive outline of coal-mine electrical power systems from theory to practice. Together, the two volumes contain the vital aspects that go into planning and designing a mine power system. After a short introductory chapter, Chapter 2 discusses the history of electrical use in mining and introduces "typical" mine- power-system arrangements. Chapter 3, 4, and 5 supply basic information on electrical theory, circuit analysis, and motors. Next, the Grounding and Distribution Chapters detail unique aspects of mine power systems. Elements of surface and underground use are included in all these chapters. An index concludes Volume I and is cross-referenced to both report volumes.

Jan 1, 1982

Jan 1, 2005

The Bureau of Mines is responsible for a broad spectrum of programs for meeting the diverse and changing mineral resource needs of the Nation. These programs are managed by the Director and two Deputy Directors, who formulate general policy and program direction from the Washington, D.C., headquarters. A senior advisory staff, consisting of the Chief Staff Officer, Chief Scientist, and Chief Mining Engineer, provides advice and consultation to the Director on a wide range of scientific and technical matters and acts on behalf of the Director to maintain liaisons with other government agencies, mineral industries, and professional societies. Bureau program activities are classified into two major functions: (1) Developing new and improved technology that will make the production and processing of minerals more efficient, safer and more healthful for mineral workers and the public, and more compatible with a quality environment.

Jan 1, 1980

By M McCurd, M Lynch, B H. Yin, S Mendoza, C W. Bumby, Y Iwasaki, B Rumsey

Iron and steel production is responsible for approximately 6.3 per cent of global anthropogenic CO2 emissions. Direct reduction of iron with hydrogen is a potential route for decarbonising the iron and steel industry. Extensive small-scale laboratory experiments have been performed to test the feasibility of hydrogen-direct reduction of iron ores sourced from diverse geographical locations. However, test results from the batch reduction of small-sample do not necessarily translate to continuous commercial-scale processes. Establishing a small-scale continuous test reactor for H2- DRI process is challenging, requiring substantial resources and investment. The limited availability of small-scale reactors that enable testing under relevant conditions has become a major obstacle for H2-DRI development, leaving a big gap between laboratory success and proof of commercial feasibility. Here, we report on the recent commissioning of a continuous counter-flow vertical shaft reactor, which has a processing capacity of 6 kg/hr iron ore pellets at up to 100 NL/min H2 flow. We believe this to currently be the largest H2-DRI facility in the Southern Hemisphere. In this talk, we will discuss the design and construction journey for this reactor, starting from the initial system design to the initial demonstration of H2 reduction of titanomagnetite ironsand pellets. This reactor now enables a range of research capacities, including the validation of laboratory results on a larger scale with practical operational variables, feasibility assessment of hydrogen direct reduction of different iron ores on a commercial scale; identification of scalability, sticking, and other potential issues before building a full-scale plant; and a viable solution for producing small-quantity DRIs for downstream melting investigations. Overall, this new research facility offers significant benefits for assisting the transformation of iron and steel production to a more sustainable and green industry.

Sep 18, 2023

By Steve Kral

"Each January, tunneling and underground professionals gather in New York City for the George A. Fox Conference. The one-day event offers attendees the opportunity to listen to their peers outline what’s new in the underground construction industry, get updates on major projects in North America and have a chance to catch up of old friends.The conference is put on by the Underground Construction Association of SME. This latest conference attracted about 370 specialists in the industry. The theme for this year’s event was “Water Tunnels, Past, Present and Future.”The technical session included talks focused on major tunneling projects, including the massive California Water Fix program and the Massachusetts Water Resources Authority (MWRA) Metropolitan tunnel redundance program in Boston. The conference also included an update on the Gateway Project from Phil Rice from WSP and Mahammed Nasim of Amtrak as well as a Tunnel Industry update.The following is a sample of a few of the presentations. Technical presentationsDEP’s Tunneling Program Evolution. James Mueller is the agency chief engineer of New York City’s Department of Environmental Protection (DEP). Its mission is to plan sustainable infrastructure investments for the future of clean water and the environment in the city and its watersheds, he said. The agency’s goals are to synthesize information across bureaus within DEP to allow data-driven decision-making. It is also to optimize internal agency processes and systems related to the implmenation of engineering programs within a structured assessment process. The agency also prioritizes projects and funding within a structured integrated planning process. And it standardizes project performance and delivery to meet the needs of the agency in alignment with industry standards and market capabilities."

Mar 1, 2019

By E. M. Norris

Phosphate deposits are distributed widely over the earth's surface. Of the known areas of deposit, eight fields are of particular interest because of their vast reserves of high grade phosphatic material and the volume of their production that goes to the world's great consuming areas. These fields, in the order of their present economic importance, are situated respectively in Florida, French Morocco, Kola Peninsula of U.S.S.R., Tunisia and Algeria, Tennessee, Montana-Idaho-Wyoming-Utah, Ocean and Naru Islands in the Gilbert group, and in Egypt. The Rocky Mountain deposits have a comparatively low ranking in the phosphate trade of today, but this field contains one of the largest known reserves of phosphatic material, associated with which are recoverable trace minerals, which are of increasing importance in our national economy. The first discoveries of phosphate rock in the western states were recorded in Cache1 and Rich2 counties in Utah, respectively in 1889 and 1897. Mining operations were begun on these deposits near Montpelier, Idaho, in 1906. During the latter year geological studies of the phosphate beds were started by Weeks and Ferrier of the U. S. Geological Survey. These studies have been continued to the present day by a distinguished roster of the Survey's technicians. As a result of this systematic exploratory program, the Survey has published a series of bulletins, papers, and maps, which provide the mining public with a comprehensive study of the exposed

Jan 1, 1949

By Bengt H. Fellenius

.1.1 Prior to commencement of pile installation operation, submit to [Engineer] for [approval] [review], details of equipment for installation of piles. SPEC NOTE: The information requested in 3.1 .1.2 is necessary as input to a detailed wave equation analysis of the pile driving. .1.2 For impact hammers, give manufacturer's name, type, maximum rated energy and rated energy per blow at normal working rate during easy and at termination driving, mass of striking parts of hammer, mass of driving cap, and type and elastic properties of hammer cushion. .1.3 For non-impact methods of installation, such as drilling, jacking, jetting, use of vibratory hammers, or other means, give full details of characteristics necessary to evaluate performance. .2 Impact Hammer SPEC NOTE: Do not exclude a hammer type unless for very specific reason. .2.1 [Drop hammers will not be permitted.] [Diesel hammers will not be permitted.] For final driving of [TYPE] piles, provide a hammer capable of delivering to the pile a non-erratic impact stress not smaller than [VALUE] Pascal and transferring a non-erratic energy not smaller than [VALUE] Joules per blow to the pile head at normal working rate.

Jan 1, 1991

By Arthur E. Morris

Fifty years ago when Professor Yazawa began his career, the field of process simulation and modeling was in its infancy. Since then, tremendous progress has been made in our ability to model metal production flowsheets from mine to refined metal. This progress has come about by parallel developments in basic understanding of process chemistry and in computational techniques. This paper will review the progress made in process understanding and modeling in lead, zinc, and copper metallurgy from its inception to the present, and the role of Professor Yazawa's work in furthering this progress. Specific examples wi1\ be given for the sintering of lead concentrates, slag fuming, zinc concentrate roasting, flash smelting of copper, and pyro-extraction of zinc. Factors limiting further progress will be described.

Jan 1, 2003