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By R. J. Hundermark, L. R. Nelson

The critical importance of tap-hole design and management to furnace performance and longevity is explored through examining some of the specific matte, metal and slag tapping requirements of non-ferrous copper blister and matte converting and smelting, ferroalloys smelting and ironmaking systems. Process conditions and productivity requirements and their influence on tapping are reviewed for these different pyrometallurgical systems. Some critical aspects of the evolution of tap-hole design to meet the diverging process and tapping duties are examined. Differences and similarities in tapping practices and tap-hole management are reviewed. Finally core aspects of tap-hole equipment and maintenance are identified that are considered important to securing improved tap-hole performance and life, so pivotal to superior furnace smelting performance.

Jan 1, 2014

By B. Tulu, D. Gearhart

A comprehensive monitoring program was conducted to measure the rock mass displacements, support response, and stress changes at a longwall tailgate entry in West Virginia. Monitoring was initiated a few days after development of the gateroad entries and continued during passage of the longwall panels on both sides of the entry. Monitoring included overcore stress measurements of the initial stress within the rock mass, changes in cable bolt loading, standing support pressure, roof deformation, rib deformation, stress changes in the coal pillar, and changes in the full three-dimensional stress tensor within the rock mass at six locations around the monitoring site. During the passage of the first longwall, stress measurements in the rock and coal detected minor changes in loading, while minor changes were detected in roof deformation. As a result of the relatively favorable stress and geological conditions, the support systems did not experience severe loading or rock deformation until the second panel approached within 30–50 ft of the instrumented locations. After reaching the peak loading at about two to three inches of roof sag, the cable bolts started to unload, and the load was transferred to the standing supports. The standing support system was able to maintain an adequate opening inby the shields to provide ventilation to the first crosscut inby the face, as designed. The results were used to calibrate modeled cable bolt response to field data and to validate numerical modeling procedures that have been developed to evaluate entry support systems. It is concluded that the support system was more than adequate to control the roof of the tailgate up to the longwall face location. The monitoring results have provided valuable data for the development and validation of support design strategies for longwall tailgate entries.

Jan 1, 2017

By Vince Saporito

Miners work in dangerous terrain, around the clock, with heavy equipment. Is there room for improvement in safety and standardization in the mining industry? Recent history would suggest there is a need for action. At a 2011 Spring Thaw conference in Denver CO, one speaker commented, ?We are having a number of incidents with workers getting ?pulled? into rollers or ?trapped? at transfer points when trying to manually clean (it) while the conveyor is still in motion.? It?s a troubling thought. These actions are specifically prohibited under U.S. Mine Safety and Health Administration (MSHA) regulation 57.14202. Another official from MSHA earlier this year indicated with today?s technology and policies presently in place, ?we should not be repeating the same incidents and violations year after year as we currently do.? But we are doing exactly that.

Jan 1, 2012

By Diana Drinkwater

As ore grades decline, ore deposits get harder and mineralogical complexity increases, metallurgical skills are more important than ever to ensure that today?s mining operations are operating efficiently and profitably. Yet specialist undergraduate degree programs have all but disappeared and metallurgical skills training for graduate engineers in the workspace if often haphazard. In response to this situation, specialists at the JK Centre in Queensland, Australia, have put together a professional development program designed to fast-track skills development for early career metallurgical professionals. The program, called ?MetSkill ® ?, is offered as a group training package for young metallurgists in the workplace. It is centred on a meaningful technical investigation negotiated between the JK Centre delivery team and the client company. As well as learning about project management and data collection and analysis, the participants study specialist topics such as comminution, flotation and mineralogy under the tutelage of senior research and consulting professionals. The technical investigation provides an opportunity for immediate practice of these new skills and JK Centre specialists are on hand to provide feedback and support throughout the program. The participants are employed across different operations in Australia and the Asia-Pacific, and although they occasionally come together for group training activities they are often separated by considerable distance. Specialist educational professionals from The University of Queensland have provided an innovative web platform to support collaboration and communication between all participants. This paper will describe the MetSkill ® program in detail, as well as providing a report on its initial roll-out to 2 groups of Australian graduate metallurgists in 2012

Sep 1, 2012

By P. R. Dugan

Sulfur removal from high sulfur coal has several objectives including: a) reduction of the atmospheric load that contributes to the problem of acid precipitation; b) reduction of ash, which contributes to decreased energy transfer in boilers, as well as ash disposal; and c) alleviation of the social and economic dislocations related to uneven geographical distribution of sulfur in coal reserves. Cost in relation to the value of refined coal will govern the development of an emerging coal refining industry. Estimation of the premium paid by power companies for coal with a low sulfur content is a good estimate of the value that will be added as the result of refining. Estimates of premiums paid in 1984 are $28.65/t ($26 per st) for reduction of total sulfur from 370 to 1% S and greater than $28.65/t ($26 per st) for removal below 170 sulfur.

Jan 1, 1988

By Osvaldo A. Bascur

Intelligent systems (IS) technologies have received much attention in a wide range of process engineering applications including process operations. With the revolutionary progress in information and computer technologies applying the latest technologies in metallurgical complexes has become a serious challenge to both management and technical teams. Objects and components are changing the way everyone relates to their computer and networks. Goals of real time performance monitoring includes maximizing the profitability by maximizing production, improving efficiency, attending product quality, costs, maintenance, environmental and safety regulations. Designers must consider the greatly expanded desktop computing, Microsoft object technology, Internet and how to build these systems. This paper discusses some opportunities and challenges using objects, components in designing applications and integrating intelligent systems tools. Two examples using performance equations and IS technologies applied to mineral processing are presented.

Jan 1, 1997

Those involved in the mining and minerals industry really are an optimistic bunch. Faced with an economic downturn that has spread across the globe ? one, some say, that crept up on everyone ? mining professionals remain hopeful that the industry will return. An example of that optimism is the attendance at two of the industry?s key conferences and exhibitions. In February, more than 4,200 people attended the SME Annual Meeting and Exhibit in Denver, CO. And a week later, in Toronto, Ontario, more than 18,000 were on hand for the Prospectors and Developers Association of Canada?s (PDAC) meeting. Both are respectable numbers and run contrary to meeting attendance figures during previous downturns when attendance and the numbers of exhibitors fell off significantly. Like other downturns, this most recent one has resulted in massive layoffs, curtailments of production and outright closures. Exploration has been hard hit and many junior mining and exploration companies will either disappear or be swallowed up by others. Gold is its usual self The PDAC generally attracts the gold mining and exploration sectors. So that might explain some of the optimism at the meeting. Unlike base metals and construction materials, gold, not surprisingly, is doing well. And most of the companies in the Investors Exchange at PDAC were involved with gold. While the balance sheets for most base metals companies look bad, gold companies appear to be not as hard hit. Gold is doing what it usually does during a downturn ? act as a safe haven while the value of other assets collapse worldwide. Governments around the world are preparing to pour trillions of dollars in an attempt to resuscitate their economies. This will likely lead to inflation, some experts at the PDAC convention said, which will be good for gold. And gold mining companies are also benefiting from lower production costs. The result is that some gold watchers believe gold could reach $64/g ($2,000/oz) at some point.

Jan 1, 2009

By A. Galaitsis

This report summarizes part of the work performed under the USBM Contract No H0155113, "Noise Abatement of Continuous Mining Machines." It describes the noise source diagnosis of a Jeffrey 120M conveyor and the evaluation of several treatments all conducted in a test facility aboveground. The conveyor noise at the operator's position was gradually reduced from 101.5 to 93 dBA using damping, vibration isolation, sound barriers and smoother discontinuities. The underground performance of the selected treatments will be addressed in Volume II of the report.

Jan 1, 1979

By C. H. McNaughton

The Tennessee Copper Co. operated two mines in the Ducktown district during 1928. The Burra Burra mine is much the larger operation and is the chief source of the ore smelted and treated in the, company's smelter and acid plant rat Copperhill, 4.5 miles from Ducktown. This mine operates steadily and furnishes a regular output of about 40,000 tons per month. The Eureka mine is operated irregularly and produces a much smaller tonnage of high-sulphur ore the rate of output depending upon the demand for sulphur. During 1928 about 60 per cent of the combined output of these mines was shipped directly to the smelter, and the balance was concentrated before shipment in the flotation plant located near the mines. ACKNOWLEDGMENTS The author acknowledges the assistance of Lamar Weaver, Assistant mine superintendent of the Tennessee Copper Co, and of C. F. Jackson, mining engineer, U. S. Bureau of Mines, in the, preparation of this paper, U. S. Geological Survey Professional-Paper 139, by W. H. Emmons and F. B. Laney, has been drawn upon for information contained 'in the paragraphs on history and geology.

Jan 1, 1929

The captions to Figs. 1 and 2 of the paper by B. J. Parry entitled 'High-strength cold-rolled steels' should read as follows:

Jan 1, 1984

By David C. Byrne

PURPOSE: Evaluate practical technological advances in hearing protective devices for use in different mining environments. RESEARCH SUMMARY: Previous NIOSH research shows that miners develop hearing loss much more quickly than nonoccupationally noise-exposed individuals and that miners experience a greater severity of hearing loss than would be expected for nonoccupational noise-exposed persons of the same age and sex. As described in the National Occupation-al Research Agenda, problems created by occupational hearing loss include(1) reduced quality of life due to social isolation and unrelenting tinnitus,(2) impaired communication with family members, the public, and coworkers, (3) diminished ability to monitor the work environment (i.e., warning signals, equipment sounds, etc.), (4) lost productivity and increased accidents resulting from impaired communication and isolation, and (5) expenses for workers’ compensation and hearing aids. Although eliminating hazardous noise is the long-term solution to the noise problem, miners will likely need to rely on personal hearing protection in certain situations for quite some time. However, it is well known that noise attenuation provided by hearing protectors as they are worn during everyday use is usually quite different (i.e., worse) than when tested under lab conditions. In addition, workers may refuse to wear their hearing protection for any number of reasons. This project was initiated to evaluate practical technological advances in hearing protectors, with an emphasis on optimizing the balance between effectiveness, comfort, over protection, and communication ability. The recently completed auditory research facility is now under-going the accreditation process conducted by the National Institute of Standards and Technology under the National Voluntary Laboratory Accreditation Program. Experiments are planned to investigate the factors that affect a miner’s ability to hear hazard and warning sounds (e.g., roof working, alarm signals, spoken communications, etc.). A service contract has been initiated to record and digitally store samples of typical warning sounds heard in an underground coal mine. This information will be analyzed in the lab to develop recommendations that can be offered to the mining community regarding correct earplug/earmuff usage to maximize there cognition of hazard and warning sounds while adequately protecting the miners’ hearing.

Jan 12, 2001

By John R. Bartels

This report discusses an improved method for rerailing underground railcars devised in a joint effort by the Bureau of Mines and Hoesch MFD. This improved method utilizes a lightweight hydraulic ram with hand-pump activation to move a bridge-mounted roller carriage in conjunction with steel-reinforced air-lift bags. This method provides a lightweight portable system in which only two workers are required to perform the mine car rerailing operation. Because of the very narrow confines in underground mines, use of overhead cranes and other surface rail techniques is not possible. This new system is designed for very low profile work, and provides the necessary lifting force from light- weight compressed-air bottles.

Jan 1, 1985

By N. C. Saxena, S. K. Puri, A. K. Pal

The condition-based monitoring system is an important innovation for reducing the downtime of costly, heavy earth- moving machinery (HEMM). Vibration severity measurements were made on the HEMM located at the Gevra Project, the largest coal opencast project in India. Whenever the vibration severity levels exceeded the permissible limits, necessary actions were taken to replace the defective parts of the ma- chine. The systematic vibration monitoring of 120-t (132-st) dumpers, followed by corrective measures led to a substantial increase in component life (8.18% for an 445E Dressor and 28.44% for an MK-30 Unit Rig). The associated costs (including spareparts) were reduced by 21.55% and 25.74%, respectively. Because of the reduced downtime, savings for these two dumpers over the period from March 26 to June 25,1998, were of the order of Rs.26.47 (US$0.649) million.

Jan 1, 2000

By Anna Paula Littig Berger

A remoção do fosfóro através do processo de desfosforação do ferro-gusa tem sido cada vez mais relevante, devido a influência que exerce de forma prejudicial as propriedades do aço e devido a extensão do cenário de escassez de minérios com menor teores de fosfóro. Este trabalho tem como objetivo a avaliação termodinâmica de misturas à base de dolomita e finos de minério utilizadas no processo de desfosforação realizado em panela para o refino do ferro-gusa. Verificou-se uma tendência de maiores valores de eficiência para o processo de desfosforação quando aumenta-se a razão de massa de desfosforante e massa de gusa.

Aug 17, 2017

By John Wellington Finch

WHAT is an engineering opportunity? To the mining .engineer the natural assumption is that the first requisite 'is a mineral deposit, but, of course, it is not so simple as that. There are at various points on the earth really very great mineral deposits which, on account of geographic location, backwardness of the country, or hostility of its natives, are now, and for a long time to come will be, quite valueless. The mining engineer, and for that matter the civil engineer, is more dependent upon the decisions of capital than upon any other factor in his profession. Ordinarily it is to be assumed that money will go to any place where it is clear that an adequate return upon its investment can be secured, but for many years it has not been safe to depend upon this. ' As already stated, there are many places where local conditions are such that mining is not safe to engage in and there are still other places in which conditions have been so aggravated by the Great War and by the social unrest which has upset the Asiatic region that capital is naturally most reluctant to venture, even when engineering data makes the undertaking appear attractive. It will be evident, I. believe, that there are many factors vital to the success of a mining enterprise in some of the remote countries which we do not have to consider in the United States and which do not, in fact, exist here.

Jan 1, 1924

By K Akiro

Volcanogenic massive basemetal sulphide and gold mineralisation of predominantly low sulphidation style has been located within Lower Tertiary basaltic and felsic volcanic and sedimentary sequences at Ufuo, in the Left April River area, northwest Papua New Guinea. The four discrete massive sulphide bodies, which have been so far identified, occur within a 3 +5 km area situated within a north west trending structural corridor. The sulphide bodies are all localised on the margins of the corridor where the bounding major through going faults are transected by regional faults. Mineralisation is characterised by massive pyrite-bornite-sphalerite-barite-quartz-anhydrite deposition with later galena-tennantite-chalcopyrite. Minor phases include enargite, goldfieldite and bismuth sulfosalts. Jasperoidal silica lenses and bioturbated sediments are closely associated with the massive sulphides. Basemetal sulphide mineralisation is also closely associated with phyllic-style quartz-sericite- altered host rocks underlying the massive sulphide lenses. This mineralised phyllic alteration is localised to fractures, veins and breccias that cross-cut propylitic style alteration characterised by quartz, epidote, chlorite, adularia and zeolite. The mineralised system possesses several hydrothermal features consistent with a copper-rich submarine exhalative volcanic hosted massive sulphide (VHMS) system, ie discrete massive sulphide bodies with abundant barite, associated jasperoidal silica and bioturbated sediments. However, exploratory drilling of the alteration zone underlying each of the massive sulphide bodies has not identified a well-defined zoned alteration pipe that is characteristic of such systems. The alteration is also similar to that of a porphyry-related low sulphidation system in which phyllic alteration has overprinted a regional propylitic style assemblage. The presence of sporadic enargite (and ?tennantite/tetrahedrite) suggest there were intermittent pulses of acid fluids in the system probably derived from exsolved magmatic SO2 which flowed directly to the surface along reactivated faults. The occurrence of tellurium and bismuth minerals is also consistent with a magmatic contribution to the metalliferous hydrothermal fluids. It is proposed that the VHMS orebodies are the products of submarine exhalative deposition generated by a crystallising magma emplaced within crust of on-going tectonism. Ufuo mineralisation is similar to many VHMS deposits elsewhere in that it is unclear whether the metals are derived from the magma directly, or via seawater leaching of the wallrock. Additional studies such as oxygen isotope analysis may assist in resolving this issue. If the metals are shown to be of direct magmatic origin then there may be good prospects for discovering economic-grade porphyry-related mineralisation at depth below the massive sulphide deposits.

Jan 1, 1999

By B. A. Ashley

In 2007, Rosebud Mining Company (RMC) opted to extend the reserve base of Tracy Lynne Mine by developing through a sandstone channel. The extension provided access to approximately 6 million additional recoverable tons (approximately 8 years of mining) which originally had been deemed inaccessible. An evaluation of the mine?s existing ventilation system, which was designed to meet the needs of the original limited reserve, concluded that two ventilation shafts would likely be required to adequately ventilate the projected workings in the expanded reserve. To assist in the evaluation, a ventilation model of the mine was developed using Ohio Automation?s ?ICAMPS MineVent? software based on field data from Tracy Lynne Mine, prior ventilation survey experience at similar RMC mines, and relevant published sources. Model results suggested that the most economical shafts would be an 8-ft diameter return and a 4-ft diameter intake. Unfortunately, issues related to property leasing and shaft site permitting caused construction delays. Therefore, the model was also used and proved to be effective in prioritizing interim ventilation upgrades which could be implemented in order to maintain coal production. Model results indicated that the best interim upgrades included rehabilitating restricted entries and damaged stoppings and replacing the main fan with a higher pressure fan. From late 2010 to mid-2012, all interim upgrades and shafts were implemented. Current models and mine experience indicate that ventilation will not be the limiting factor for mining the additional reserve.

Feb 23, 2014

By Terry R. Neumann

In 1987 and 1988, the U.S. Bureau of Mines conducted a mineral resource investigation of the 31,400-acre Muddy Creek Wilderness Study Area (UT-060-007). The investigation was requested by the Bureau of Land Management and authorized by the Federal Land Policy and Management Act of 1976 (Public Law 94-579). The study area is located in Emery County, Utah, about 50 air-miles southwest of Green River, Utah. The wilderness study area is in the San Rafael Swell region of the Colorado Plateau Physiographic Province. Rocks in the area consist of gently dipping sedimentary strata of Permian, Triassic, and Jurassic age.

Jan 1, 1988

By Milford L. Skow

This report summarizes the principal activities and results of 15 years of research by the Bureau of Mines, U.S. Department of the Interior, on methane control in coal mines. This research has investigated fundamental factors regarding the occurrence and movement of methane in coal beds, removal of methane prior to mining, and control of methane during mining. The report includes a bibliography listing the more than 150 publications resulting from the Bureau's methane control program as well as numerous other references, a section on methane recovery and use, a look at the upcoming Bureau of Mines research program, and a brief review of methane drainage practices in other coal-producing countries.

Jan 1, 1980

By S. M. Dar

The U.S. Bureau of Mines constructed a full-scale model of a 15-ft-wide coal mine entry to use in combination with finite-element analyses to investigate roof support systems and various types of roof bolts. The objective was to enhance understanding of the fundamental mechanics of the interaction between rock and supports and the relative integrity of bolted mine roof as a function of roof bolt type, length, spacing, and tension, and the basic characteristics of the roof strata. The laboratory test results, when correlated with computer simulations using fmite-element analysis and underground verification tests, should provide a basis for desigillng safer, more cost-effective roof control systems and help to establish guidelines for employing fully grouted resin and mechanically anchored bolting systems. The background for this research, the research approach, the methods and equipment employed, and the results are described in this report.

Jan 1, 1989