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On July 1, the Bonneville Power Administration announced a 25% power cutback because of lower than normal stream flow. In September, the Aluminum Company of America (Alcoa) announced plans to shut down one 23,000-ton-per-year potline at its Vancouver, Wash., primary aluminum smelter. Alcoa also announced that the last of four potlines at its Point Comfort, Tex., primary aluminum smelter would be restarted in October. A new 3-year contract was signed and workers at three Alcan Aluminum Ltd. primary aluminum smelters in Canada returned to work. It was estimated that it would take about 3 months before the smelters were operating at full capacity.

Jan 1, 1979

By Richard E. Thill

Engineering properties of rock are essential in most phases of mining from site reconnaissance through mineral processing. Review of the literature indicates, however, that property data is scarce for most coal measure rocks in the United States. The Bureau of Mines, U.S. Department of the Interior, has undertaken a wide-ranging testing program to provide more complete property data for coal strata in the U.S. coal basins. The property data are expected to have application in geophysical exploration, the development of pre- mining and hazard detection probes and instrumentation, mine design, engineering and rock mass classification, subsidence engineering, and ground control. This paper describes the comprehensive program encompassing in situ geological, geophysical, and geotechnical properties and laboratory determinations of acoustic, electromagnetic, physical, mechanical, and index properties and discusses results for 500 ft of coal measures at a minesite in the Northern Appalachian, Eastern Coal Province.

Jan 1, 1982

By B. Solar Menéndez, M. B. Díaz Aguado, I. Á. Fernández, C. González Nicieza

The analysis of subsidence due to the opening of an underground void (mining, water exploitation or civil works hole) is a problem usually hard to solve. First of all, it requires a predictive model, in order to define both the displacement magnitude and area affected by subsidence. Such model should be validated with measurements of the actual movements sustained on the surface, in order to adjust it properly and enable influence of future behaviour in a reliable way. Two different kinds of problems might arise. On one side, it is necessary to control and measure surface movements in a very exhaustive way during a long period of time, beginning before underground works take place and finishing years after they are over. Furthermore, three factors bring in errors, some times of magnitudes higher than the displacement magnitudes measured. These include: the fact that reliable and long-term information cannot always be achieved; the precision of measuring devices; and the design of the topographical network itself. In addition, the predictive models more widely used only apply to certain excavation geometries, mainly to horizontal holes. In light of this background, the Group of Rock Engineering, of the University of Oviedo Mining Department, has developed a working methodology and a specific software tool, Subsidence 3D, to estimate ground displacements and strains. The program will allow for predictive models to be defined and also allows the treatment of data related with topographical marks and its comparative analysis with calculated results. The software has been programmed using Visual C++. Graphical outputs however are generated using AutoCAD 2000. This paper mainly refers to a practical situation, an underground coalmine, remarking the main difficulties arisen during the study of the available information and proposing how to solve them. A predictive model in subsidence 3D was established and validated. The actual behaviour of the ground was that in the model.

Jan 1, 2003

By Benjamin W. Haynes

The Bureau of Mines conducted research to provide technical information needed to devise waste management plans for the processing of manganese nodules. Studies included summary descriptions of Pacific manganese nodules, process options and flowsheets, methods for characterizing nodules and their tailings, and results of analyses of laboratory and pilot-plant generated tailings. This information is the result of a cooperative research effort of the Bureau of Mines and the National Oceanic and Atmospheric Administration (NOAA), with NOAA providing funding and the Bureau conducting the research. A summary of the extensive literature review is provided for manganese nodule mineralogy, chemistry, processing techniques, and methods of analyses. Characterizations and analyses of laboratory-generated tailings and slags are given, as well as the results of the leaching studies on these waste materials. Leachability was determined by three standard leachate tests- the Environmental Protection Agency (EPA) extraction procedure (EP) toxicity test, the American Society for Testing and Materials shake extraction test, and the U.S. Army Corps of Engineers-EPA seawater elutriant test. While the wastes generated in the laboratory may not be entirely representative of those to be generated in full-scale plants, results of these studies provide a positive indication that commercial recovery of cobalt, copper, manganese, and nickel from manganese nodules would be environmentally acceptable.

Jan 1, 1985

By D. Harrington

For many years the Federal Bureau of Mines-in cooperation with other agencies-has been making investigations and compiling and publishing reports and statistics on accidents in the various branches of the mineral industry.4 Its assistance has been enlisted also in health, safety, and ventilation problems' incident to the driving of many large tunnels in the United States in recent years. As part of this work the Bureau has compiled considerable statistical and other information on accident experience in the tunneling branch of the heavy-construction industry. It has always been difficult to obtain up-to-date information on tunneling methods and tunnel accidents. Published accounts of tun¬nel construction furnish much interesting material of engineering, historical, or fiscal value, but usually little or no attempt is made to discuss and critically analyze the means taken to preserve the health and life of employees.

Jan 1, 1941

By N Clarke, G R. Ballantyne, M S. Powell, P Elms, A Anyimadu

AngloGold Ashanti Ltd nominated Sunrise Dam Gold Mine as a case study via their involvement with the long-running Australian Mineral Industry Research Association (AMIRA) International P9P research program (AMIRA, 2015) . A group of researchers from the Global Comminution Collaborative (GCC) conducted a comminution circuit survey and review together with a large group of graduate metallurgists, senior metallurgists and operators. Fundamental and applied research understanding was used to identify productivity and efficiency improvements around the crushing and grinding circuits. The limitations of current scientific knowledge were identified through this process and this will allow future research to be more focussed on what is required by industry.The comminution circuit at Sunrise Dam comprises three stages of crushing followed by two stages of ball milling. The secondary crusher and primary ball mill classification were identified as the primary limitations of the circuit. The secondary crusher was found to be underperforming through overall equipment efficiency (OEE) analysis and an improved chamber design was identified by Chalmers University. This improved design will promote higher power utilisation, choke feeding and a finer crushed product for the milling circuit. The primary ball mill product is classified by a combination of a trommel, 3 sieve bends and a hydrocyclone. The combination of poor classification and coarse, competent feed led to a situation where the primary mill was overfilled with rocks, reducing grinding rate due to cushioning of impact. Size specific energy (SSE) benchmarking methodology was used to identify that a 10% increase in throughput could be achieved with improved primary classification.CITATION:Ballantyne, G R, Clarke, N, Elms, P, Anyimadu, A and Powell, M S, 2015. Application of research principles to identify process improvement at Sunrise Dam Gold Mine, in Proceedings MetPlant 2015, pp 221–229 (The Australasian Institute of Mining and Metallurgy: Melbourne).

Sep 7, 2015

By R Kroukamp

Horizontal belt filters are typically used for separation of relatively free filtering solids where good post treatment is required. He horizontal belt filter is a continuous filter with an endless cloth supported on a grooved carrier belt. The belt and cloth are driven around two rollers across a series of evacuated suction boxes. The feed suspension is introduced at one end of the filter and deliquored to produce a cake at the other end. The benefits of using horizontal belt filters are good cake washing, continuous and visible processing, fully automatic operation, flexibility, high capacity and relative high speeds of operation. If required, horizontal belt filters enable efficient counter-current washings to minimize the usage of wash liquid. The horizontal belt filter has applications in the following: [? Metal concentrates ? Mineral sands ? Tailings ? Coal ? Iron ore ? Alumina ? Chloride processing ? Nickel and Cobalt refining ? Platinum group metals ? Zinc processing ? Many other applications in the Mining and Metallurgy industries ] 2. Operating Principle of a Horizontal Vacuum Belt Filter 2.1 Cake Forming The slurry to be dewatered is evenly distributed onto the filtering surface. Gravity assists the cake formation and the feed can be introduced in multiple stages. 2.2 Cake Washing Once the cake is formed, wash liquor/water can be introduced onto the top of the cake via a wash launder or sprays. Multiple wash stages, co-current, counter-current or direct washing can be added by increasing the length of the filter.

Jan 1, 2007

By Sutham Niyomwas

The Fe-TiC composite powder was synthesized in situ by carbothermal reduction of ilmenite. The standard Gibbs energy minimization method was used to calculate the equilibrium composition of the reacting species. The effects of the reaction temperature (1300 °C - 1500°C) and milling time of precursors on the Fe-TiC conversion and powder morphologies were investigated using XRD and SEM method. The synthesized products showed that composite with iron matrix and titanium carbide as a reinforced phase was formed.

Jan 1, 2006

By D. Randolph Berry

The objective of this program was to develop a system to extinguish coal mine fires by remote sealing of the underground passageways. The system developed had to be versatile enough to function under a wide range of operating conditions, including large variations in passageway geometry, depth of mine, water conditions, both in the mine and at the surface, and rubble in the mine passage. The system developed had to include instrumentation for the remote probing of the passageway prior to sealing, a system for sealing the mine passages, and instrumentation for remote monitoring of the quality of the seal during and after construction. These objectives were successfully achieved during this program. The remote mine sealing capability of the system was satisfactorily demonstrated in a field test conducted at the Eastern Associated Coal Corporation Federal No, 1 Mine in Grant Town, West Virginia.

Jan 1, 1973

By AIME AIME

TRANSFER to the Bureau of Mines of the responsibility for conservation and production of helium, and announcement that a proposal has been made to the President for commercial operation of the Los Angeles has attracted new attention to the helium program of the Government. The matter is one in which mining engineers, and the mining industry in general, have a peculiar interest. Helium is a byproduct of the petroleum and natural gas industry. It is found in certain of the natural gases which have themselves been discovered, in the main, in the search for oil. If it is to be produced on a large scale, the conservation and development of the fields will necessarily be done by the men of the oil and gas industry. There is no known or expected source of supply of quantities of commercial importance save in the natural gas fields. Not all gas wells supply helium and none of them supply it in important percentages. If it were necessary to prospect a field, develop it, lay pipe lines and build production plants for the helium alone, the cost would be prohibitive. On that basis helium would necessarily be restricted to essential war uses, where cost is subordinate to need. As a byproduct of the natural gas in certain, at least, of the fields in the United States there is distinct reason for anticipating that it may be produced in amounts and at a cost that will permit its regular use in commercial airships.

Jan 1, 1925

"In addition to outstanding technical sessions and networking opportunities, the SME Annual Conference and Expo offers attendees a chance to see the latest and greatest technology that the industry has to offer. The 2017 SME Annual Conference and Expo was no exception as 575 companies filled 756 booths from Feb. 19-22 in Denver, CO. The following is a look at some of the vendors that were on hand.AIL MiningThe Edge, featured by AIL Mining at the 2017 SME exhibit, is a four-flange structural liner designed to be an alternative to structural plate’s traditional lapped seams and to help mine operators build more efficiently and safely. It is ideal for creating underground structures, such as mine shafts, ventilation raises and escape ways. The Edge is available on SuperCor structural steel plate — 10 times stiffer and five times stronger than traditional steel liner plate. It facilitates curved structures, both horizontal and vertical, and eliminates the need for ring beams. It is ideal for remote sites. For added safety, structures can be assembled from the inside, and the leak-resistant structures can be dismantled and removed easily. Brackets can be attached to mine shafts or vent raises to support Alimak rails or climbers. Similarly, brackets or hangers can be attached to drifts or tunnels to support mine air, water or electrical utility services.ArcadisMining companies spent nearly $12 billion on water infrastructure worldwide in 2014, reflecting the industry’s heightened concern about environmental issues and social, regulatory and political risks.So, with an increasing focus on water reuse and recycling, mining companies must have effective water management plans that include sustainable solutions. Also, many water quality issues fall under both state and federal regulatory jurisdictions. To solve these problems, Arcadis provides comprehensive ground- and surfacewater technical support in a complex hydrogeologic setting. It can characterize the nature and extent of mine-related constituents in ground water and surface water, as well as the complex interactions between the two waters, and prepare the operational permits needed by mine and tailings facilities. As an example, Arcadis constructed a hydrogeologic and geochemical conceptual site model that improved site understanding for a molybdenum mine in the western United States that spanned several watersheds. It also provided technical support for permitting and compliance issues, allowing the mine to return to active production."

Jan 5, 2017

Although not immune from the problems affecting the U.S. economy generally, the mineral industry in 1991 contributed nearly $300 billion in the value of processed materials of mineral origin. Supporting this contribution, the Bureau of Mines continued the research and analytical programs highlighted in this annual review. Featured in 1991 were such relatively new programs as minewide monitoring applications in ground control and advances in processing of ceramics and composites, along with more traditional research into health, safety, and mining technology, minerals and materials science, and environmental technology. Under Bureau sponsorship, a National Minerals Policy Forum brought together some 200 executives from industry and Government concerned with minerals policy to begin a dialogue on developipng a policy statement on current minerals issues. A major feature of the forum was the keynote address by Secretary of the Interior Manuel Lujan, Jr.

Jan 1, 1992

By Edwards A. B

A suite of specimens from the newly developed Black Star copper ore body at Mount Isa was made available for mineragraphic study by the Mount Isa Mines, Ltd. The specimens were selected as representative of the different phases of mineralisation found in the ore body, rather than with a view to furnishing a complete cross-section of it; and the examination has been carried out with a view to ascertaining (1) the nature, extent and association of the arsenic, antimony and possibly bismuth, minerals in the ore, (2) the mode of occurrence of silver in the ore, and (3) whether galena and sphalerite occur in minute forms well below the sIzes readily observed in hand specimens.Analyses of the January to June, 1944, mill head composites show that the proportions of the elements Ag, As, Sb and Bi in the ore are as follows:Ag 0.000013 = 0.35 oz./tonAs 0.024Sb 0:002Bi 0.0005The copper content of the mill heads ranges from 3.5% to 4.75%, the lead content from 0.03% to 0.08,% and the zinc content from 0.09% to 0.23%.MINERAL COMPOSITIONThe specimens range from massive sulphide ore, consisting of areas of chalcopyrite, pyrrhotite, and rarely sphalerite, from 1 to 3 cm. across, to fragments of extremely finely banded pyritic shale in which no minerals other than pyrite are visible. The gangue associated with the massive sulphides is chiefly dolomite, and sometimes white quartz. The pyritic shale fragments show evidence of shearing and faulting on a micro-scale, the fractures sometimes being filled with sulphides and vein minerals.The ore minerals found in the polished sections are pyrite, arsenopyrite, marcasite, sphalerite, chalcopyrite, valleriite, chalcostibite, galena, dyscrasite, jamesonite, magnetite, gold, graphite and rutile.Pyrite (FeS2)Pyrite occurs chiefly in two forms according to whether deposition took place along the bedding planes or along the intersecting faults and fractures. Deposition of pyrite along the bedding planes of dense, thinly banded shales ha,s produced a metasomatically altered shale in which the pyritic bands are from 0.02 to 0.03 mm. wide, and alternate with bands...

Jan 1, 1945

By George B. Clark

The purpose of this investigation was to determine the feasibility of designing and testing the elements of a small charge blasting system which will eliminate, or reduce to acceptable levels, most of the undesirable features of current underground drill and blast systems, i.e., 1) air blast, 2) ground vibrations, 3) flying fragments, 4) overbreak and fracture of surrounding rock, and 5) the cyclic nature of drill and blast operations. The experimentation was conducted in tunnels in granite and the results indicate that the basic technical concepts of the project were achieved. The next step is to design, construct, and test a prototype machine.

Jan 1, 1976

By L. Stein

A simplified radiochemical method has been developed for quantitatively analyzing; radon gas in underground uranium mines. In this method, a measured volume of air is drawn by a pump through a drying tube and a cartridge containing dioxygenyl hexafluoroantimonate reagent. Radon is captured as n nonvolatile product. After radioactive equilibrium has been established between radon and its short-lived daughters (approximately 4 hours), the gamma-emission of the cartridge is measured with a scintillation counter. The amount of radon is then calculated from the gamma-emission rate. The effect of cartridge geometry, reagent load, and air flow rate upon collection efficiency and counting efficiency is reported.

Jan 1, 1977

By Dana C. Reinke

Water well drillers are exposed to high levels of noise while working. NIOSH researchers have found that water well drillers are exposed to levels above 85dB (A) while performing certain tasks during a typical drilling job. Noise levels consistently over 85dB (A) during an 8–hour work shift are hazardous and can lead to hearing loss in workers. Finding ways to reduce noise exposure is difficult because of many factors. The work environment is constantly changing due to the location of jobs and environmental factors. The types of drill rigs required for drilling are expensive. Equipment can range from new to used (10 to 30+ years old). Drillers and owners can work together to prevent noise–induced hearing loss, and measures can be taken to reduce exposure to hazardous noise.[ ] Preventing hearing loss occurs through three stages. The first stage is removing noise from the source (i.e., drill rig). Various parts of a drill rig create noise besides the drilling rod. NIOSH researchers have examined noise levels of drill rigs. Some of the loudest parts of the drill rig include the compressor, engine, and cooling fan (Fig. 1). While removing the noise source from a worksite is ideal, the process would be expensive and difficult.[ ]

Jan 9, 2005

By J. A. L. Napier

It has been established that significant time-dependent stope convergence may occur over time periods of hours and days in certain hard-rock gold and platinum mines. The source of this time-dependent behaviour appears to be associated with both pre-existing discontinuities and with mining-induced fractures that form near the stope face. These induced fractures may be associated with blasting processes and may also be formed in response to high stress concentrations in the unmined regions immediately ahead of the stope face. In shallower platinum mining operations, time-dependent behaviour is, however, observed to be much less marked unless some form of specific mining-induced fracturing occurs. One particular case of considerable interest is the time-dependent behaviour that is found to be associated with the formation and deployment of crush pillars. The purpose of the paper is to present a simple limit-equilibrium computational model of this behaviour that is sensitive to both the formation sequence and the size of planned crush pillars in a mine layout. This model provides a useful means to optimize the sizing of crush pillars, and at the same time may be used to identify potentially hazardous circumstances in which pillars may not crush in a stable manner.

Jan 1, 2012

By G. T. Lineberry

Underground mine development begins with the positive investment decision to mine and ends with the inception of full-scale exploitation. It incorporates all activities, personnel, and equipment required for creation of underground access to a mineral deposit. Because of the depletion of near-surface mineral resources, the reduced mobility of large surface mining equipment, increasingly stringent environmental constraints, and the introduction of promising innovations to rock penetration and rock excavating equipment (e.g., continuous miners, rock borers), under-ground mining is projected to account for an increased share of worldwide mineral production in the foreseeable future. Without proper engineering during the mine development phase, failure of the underground mining project is axiomatic. A frustration attendant to coverage of the complex area of underground mine development lies not only with the need for treatment of the many disparate specialties within the area but even with the lack of systematization of these specialties in what is recognized as a vital precursor to successful mining. Section17 offers insights into (1) the basic principles of the planning and design process, including baseline assessment, reserve determination, premine planning, and subsystem design (Chapter17.1); (2) equipment selection and sizing, with emphasis on exca-

Jan 1, 2008

By Eugene O. Binyon

"Belt and shaker conveyors, used singly or as combined units, have for many years been an integral part of many coal-mine haulage systems. The belt conveyor has also been used extensively as a main haulage unit in open-pit iron-ore mines of the Lake Superior district, particularly on the Mesabi Range. Few underground metal mines, however, either in the ferrous or non-ferrous branches of the mining industry, use the conveyors exclusively or even extensively for underground haulage. At present, only five iron-ore mines in the entire Lake Superior district have belt- or shaker-conveyor installations of any significant size. Of these mines, three are in the Crystal Falls-Iron River district of Michigan on the Menominee Range, one is on the Marquette Range near Ishpeming, Mich., and one is on the Mesabi Range near Keewatin, Minn.Results of the studies of tackless haulage in the Lake Superior district will not permit the establishment of any formula to prove or disprove the advantages of belt or shaker systems at all underground mines. The studies do show that trackless haulage can be used to advantage where the proper conditions exist. Advantages are particularly apparent when development can be planned sufficiently in advance of exploitation to permit installation of belts or shakers as part of the development program and where the systems are extended to include haulage in stopes as well as main entries.During the winter of 1947-48, the Bureau undertook a study of all of the underground ore conveying systems known to be in operation in the Lake Superior district for the purpose of making available to the entire mining industry the technologic data developed in the area. Because conditions that led to the installation of the belt and shaker conveying systems were often a function of the character of the deposit or the method of mining, a brief description of those conditions is included in this report.After a preliminary investigation into the extent to which trackless conveyors were employed in the district, it was found that a detailed study at five bites would result in fair appraisal of that method of haulage in the underground iron-ore mines.Each of the five significant installations is described separately in this report. In one instance, however, company policy does not permit identification of the mine wherein the conveying is done. In that instance the operation is designated as mine ""A"".Unless otherwise specified, all tonnage figures quoted herein are gross.The cooperation of officials of all of the companies operating underground mines in the Lake Superior district permitted successful completion of preliminary studies of mining practices and conveying systems.Special acknowledgment is made to R. D. Satterley, general superintendent, and to operating staffs of the Sherwood and Morris mines of the Inland Steel Co. The assistance given by W. D. Whitman, assistant superintendent, and Douglas Tippett, mine captain at the Morris mine, and P. D. Pearson, superintendent, R. O. Marsten, engineer, and W. Johnson, mine captain, at the Sherwood mine, is acknowledged."

Oct 1, 1949

By Solomon S. Katz

As more and more computer software is written for geological mapping applications, the users of the software are discovering the problems of transferring data between the programs, maintaining correct data and integrating maps produced last week with those produced today. One way to deal with these situations is by using a geographic information system (GIs). Last September the USGS and National Academy of Science held a 5-day GIs symposium on integrating technology and geoscience applications (USGS, 1988). It was followed in October by GEOTECH '88 (Peters and Krajewski 1989) which had a session exclusively for GIs applications in the Geo-Sciences. Editorials in Geobyte (Leonard, 1986, 1988) suggested that geographic information systems will be the next major computer programs to be adopted by the mineral industries. As far- back is 1985, the Computer Oriented Geological Society (COGS) printed An Introduction to GIs in their newsletter (Katz, 1985). About 20 years ago, a revolutionary idea occurred in the world of business data processing. It was the idea that all related data be stored in a standard format, in a single place and that all related computer application programs would use the same data.

Jan 1, 1989