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Electronic noses are being used in the processing industries and in fields such as environmental and occupational hygiene to detect a wide variety of problems from contaminated foods to toxic chemicals in soils. Recently, research has been conducted into the use of these devices for detecting spontaneous combustion in mines with the aim of producing a method for early detection of a developing heating. Gas samples were collected from both SimtarsÆ 16 m3 large-scale spontaneous combustion reactor and the University of QueenslandÆs two-metre column. The samples were analysed using an electronic nose. GCMS and HPLC were used to identify some of the components present. A number of issues both from a practical mine situation and a scientific standpoint have been identified that need to be addressed before these devices can be used to detect a developing heating. Aluminised bags routinely used in the mining industry to collect gas samples for analysis of the permanent gases are not suitable for use with electronic nose devices as they have a æfingerprintÆ from the polymer lining that interferes with the coal heating fingerprint. Tedlar bags used for environmental gas sampling are also unsuitable due to their fingerprint. Gas samples can be collected in glass gas bulbs with aluminium seals and successfully analysed. However the aluminium foil used to seal the bulbs is a restricted item in underground mines. It was also found that the volatile organic fingerprint of the coal heating was extremely weak at temperatures below 130¦C. Before a useful application can be developed, further investigation into the chemical species present in the off-gases from Australian coals is required.

Jan 1, 2005

By Daniel P. Lathrop, Leslie C. Taylor, William L. Fourney

Except when the target is on the surface, e.g. a tank track, the most important loading mechanism from a buried charge on a target above it is the impact of soil propelled at the target by the expanding gas from the explosion. Detonation of a shallow buried explosive generally yields an unstable interface between the rising soil and the air which appears to be the result of Richtmyer-Meshkov instability. Irregular “fingers” of saturated sand extend into the air above a more generalized dome of soil. These fingers move at a much higher velocity than the material between them at smaller stand off distances. As a result, the local load on the target at positions on the target at the same distance from the charge may vary by 50% or more from shot to shot or even within a single shot. This variation requires a large design safety factor to assure the integrity of design of mine-resistant vehicles.

Jan 1, 2009

By None None

Use this month wisely — go online and take advantage of your new member benefit. As an SME member, you can read and download for free all of the full-text papers of the Mining, Metallurgy & Exploration (MME) journal, including the 22 papers in the launch Special Issue on Mineral and Metallurgical Processing in Honor of Professor Emeritus Douglas W. Fuerstenau as well as the archived articles of Minerals & Metallurgical Processing (MMP), all the way back to Vol. 1, No. 1. Just follow the instructions on this page.

By A. Meek

This report compares the compressed air driven rocker shovel to the newly developed Warthog Non-throw development end loader. The two machines were compared on aspects such as safety, loading potential, energy efficiency and costs. The objectives of the comparison were to determine whether or not the replacement of the rocker shovel with the Warthog will be operationally and financially justifiable. The results from this study were obtained from underground observations and time studies on the machines, as well as consultations and data collection at the shaft and suppliers. This paper compares only the Warthog loader to the Trident 215 rocker shovel used at Anglo Platinum?s Brakspruit shaft and does not compare the other models of rocker shovels, which are fundamentally the same but will have different loading potentials and specifications. Cleaning times for the rocker shovel are based on underground observations at Brakspruit shaft. These times can be influenced by factors such as blasting practices, compressed air pressure and operator experience and skill. For this reason the times will most likely vary at different shafts. The Warthog cleaning times are based on manufacturer specifications and results from trial stages and therefore further work is required to confirm cleaning times achieved.

Jan 1, 2009

By C. H. Wright

Introduction The rapidly expanding and increasingly complex Canadian industrial structure, with the mining, metallurgical, and chemical industries as a large integral part, has, in recent years, brought greatly increased importance and value to our industrial minerals. In the modern economy of our mineral industry the importance which is due the non-metallics has been somewhat overshadowed by the great value of our large metal production and, in addition, by the glamour and fascination usually associated with the mining and treatment of gold ores. The term 'Industrial Mineral' is used in this paper in its usual sense and refers to non-metallics other than fuels. Coal and petroleum products, including natural gas, are considered as industrial minerals in those applications in which they are used for strictly chemical process purposes. Certain reduction metallurgical industries are so closely allied to chemical industries that for purposes been of this discussion no attempt has made to differentiate between them. Chemical industry in Canada today is a fairly large factor in our national economy, whereas in 1898, when the Canadian Mining Institute was born, it was very small indeed. Chemical concerns are largely dependent on industrial minerals for raw materials and process supplies and, as the country has developed industrially, so have the demands for non-metallics increased, not only by chemical industry but also by other large consumers, such as the construction and metallurgical industries. At the present time there is a greater than normal incentive prevailing for new discoveries, due to the serious lack of balance that exists in our import and export trade. This fact has resulted in intensive efforts to rectify the situation by locating new deposits and re-assessing those already known in an effort to enlarge and improve our home production of raw materials and also to extend their processing in Canada for our own needs and for export. The rapid advances in science and technology that have taken place since 1900 have also resulted in many cases of beneficiation and utilization of otherwise too low grade materials in order to satisfy current demands. The purpose of this paper is to indicate the history and the trends of the utilization of industrial minerals in established industry and to indicate the important part played by non-metallics in connection with the opening up of new industries. Some consideration has been given to the continual competition between natural and 'synthetic products and to the general tendency towards more rigid specifications.

Jan 1, 1948

By C J. de Beer

The Kwaggashoek East pit is one of the four production areas of Thabazimbi Iron Ore Mine. The Kwaggashoek East Open pit mines through the abandoned sublevel caving operations of the Kwaggashoek East underground workings. A risk assessment indicated that the primary risk is the occurrence of surface subsidence. Based on local knowledge, a hypothesis, that most of the cavities were filled with broken rock as a result of roof collapse and bulking of failed material was formulated. To test the hypothesis a number of geophysical methods as well as probe drilling was utilized. The results of the resistivity, gravity and ground penetrating radar surveys were inconclusive in determining the position of voids. Either there were no voids present or the resolution of the surveys was not high enough to pick it up. It is accepted that only small voids remained, and that the supported roof hypothesis is valid. As a precautionary measure all the production blast holes within the caving area were over-drilled by forty percent. This would collapse the roof of any small voids or tunnels immediately below the block. This operation proved to be successful as two of the three underground levels have been mined out with no subsidence occurring in the pit floor.

Jan 1, 2006

By A. Farnoud

Thousands of miners, construction workers, and truck drivers are exposed to diesel exhaust particles. Diesel Particulate Matter (DPM) is a probable human carcinogen and stringent occupational and environmental standards have been established or are planned worldwide. Modifications in fuels and diesel engine designs have reduced emissions, but may not be enough to comply with the tightest standards. Post-combustion aftertreatment devices are likely necessary for many engine operators. However, even the most common and well studied aftertreatment devices fail from time to time. The objective of this study was to design, construct, and test an electrostatic aftertreatment device to treat DPM. An electrostatic precipitator (ESP) was designed and constructed to capture DPM from diesel exhaust, and different configurations were tested to optimize its performance. DPM was produced by a 6 kW diesel-powered electric generator and directed to the ESP through a short section of galvanized steel pipe after the muffler. Number and mass removal efficiencies were measured with a condensation particle counter (CPC) and by sampling through a stainless steel cassette and collecting the DPM on Teflon filters. Particle size distributions were measured with and without control using a 6-stage cascade impactor. The experiments were performed with the engine running at idle and also at medium load. The results show that our first generation ESP provides 60 percent mass removal efficiency, and up to 80 percent number removal efficiency. Power consumption was generally low, about 20 to 30 watts, to achieve these levels of performance.

Jan 1, 2009

By R. E. Ray, J. W. Stevenson, J. A. Berry

Conventional concrete block plastered with a cementitious coating is the most common material used in the construction of permanent stoppings to direct airflow in underground mines in the US. All mines experience various degrees of strata convergence depending on depth of overburden, geological conditions, and type of roof support employed. Strata convergence will cause cracks and joint openings in masonry stoppings, resulting insignificant air leakage losses. Where strata convergence is severe, complete structural failure of the stopping can ultimately occur. Reconstruction of damaged or destroyed stoppings adds expensive overhead to mining operations, and even greater expenses are incurred from the additional fan horsepower required to overcome leakage losses. Ideally, a stopping should maintain high resistance to airflow while yielding to strata convergence. By properly incorporating a polyisocyanurate rigid foam material within the masonry block structure, stopping service life can be increased in mines experiencing strata convergence problems such as floor heave, roof loading, and lateral rib movement.

Jan 1, 1986

By Ernest A. Curth

The Bureau of Mines and Old Ben Coal Co. concluded a cost-sharing contract in 1975, the objective of which was to demonstrate the Herrin No. 6 coalbed in southern Illinois can be mined safely by longwall methods. Under the agreement, three longwall panels are to be mined at Old Ben No. 24 mine. A premining investigation laid the groundwork for specifying a roof-support system designed to control hazardous ground. Old Ben Coal Co. and Bureau engineers selected lemiscate-type roof shields. A rock mechanics program and geological mapping provide early warning capability and criteria for future equipment design. The effect of mining on the surface was monitored by a surface survey to develop subsidence-prediction criteria for the Illinois coal basin. The first of the three longwall panels started up in September 1976 and was completed in May 1977. The major adverse condition was the occurrence of limestone concretions, called coal balls, in massive pods. The shields provided adequate roof control even in faulty ground. Operation of the second panel started on August 1, 1977, following panel-to-panel transfer of the equipment. The accident rate was low.

Jan 1, 1978

By C. R. Hubbard

The Bureau of Mines investigated the mineral resources of the Upper Missouri River Basin as a part of a comprehensive water and related land resources study by six Bureaus of the Department of the Interior, coordinated by the Department?s Missouri River Basin Field Committee. The mineral resource study covers an area of about 18,000 square miles within the Great Plains physiographic province of central Montana. Exposed formations in the plains are chiefly flat-lying Cretaceous sediments. Plutonic rocks crop out in the central parts of the mountain uplifts, with steeply tilted Paleozoic sediments exposed around the margins. Oil and gas have been produced from several fields in the study area; total value exceeds $45 million. Coal-bearing formations of Upper Jurassic and Cretaceous age cover approximately 45 percent of the study area. Total production of coal since 1880 has been between 40 and 50 million tons, exceeding $75 million in value. Total metal production has been about $52.5 million. Industrial mineral production from 1925 through 1960, is valued at $24 million.

Jan 1, 1964

By Martin B. Hudson, Daniel Brescia, Zhangwei Ning

Due to the complexity and sensitivity of surrounding environments, instrumentation and monitoring (I&M) is critical for many urban deep excavations. The objects to be monitored include shoring bulkheads, retained embankments, adjacent buildings and roads as well as underground utilities. However, there are also plenty of constraints on the implementation of I&M such as: congested site space, difficult access to instruments, coordination among multiple contractors, and installation permits for private or public properties. Because of these constraints, sometimes the implementation of the initially planned I&M is delayed, its scope is reduced, and/or the continuity of monitoring is interrupted. For these reasons, it is important to implement the I&M with robust and redundant capabilities while providing minimal interference to the project construction and schedule. This paper describes state-of-the-art I&M technologies including automatic motorized total station (AMTS) with camera and automatic leveling device, reflectorless AMTS and IoT- based wireless sensors based on a case study of an on-going deep excavation project. INTRODUCTION In urban environments, deep excavations requiring the construction of temporary shoring bulkheads are becoming increasingly common, with the associated need to provide protection of the surrounding built environment during construction. Protection of the surrounding environment requires planning, engineering, construction, monitoring, and excessive shoring movement mitigation. The I&M is a vital component of the deep shoring implementation. In public projects, geotechnical I&M is often placed within the general contractor’s scope, whereas the majority of deep excavations are privately undertaken. For those private developments, sometimes the developer contracts the geotechnical I&M directly with the project geotechnical engineer or by a geotechnical I&M specialist hired by the project geotechnical engineer. In either the public project or private development case, the effective deployment of the I&M system relies heavily on coordination and collaboration with the project contractor.

Jan 1, 2018

By Onuralp Yücel, Süheyla Aydin, Erçin Ersundu

Turkish iron and steel sector, the base of which was established in the 1930?s, plays an important role in the industrialization and development of the country?s economy. In Türkiye this sector is the major consumer of ferroalloys. There had been a great improvement in Turkish Iron and Steel industry, especially after the 1980?sand as a result, 20.9 million tons of yearly crude steel production placed Türkiye 11th in the global steel output and 3rd in Europe. 15 % of steel produced in Türkiye is flat products, while the long products make the rest. The product composition and the general characteristics of steel production process led to an increase in ferroalloy consumption. Domestically consumed ferroalloys are especially ferromanganese, silicomanganese, and ferrosilicon. As of today, ferroalloy production capacity of Türkiye is 173,800 tons/year; 161,500 tons of which is ferrochrome with high and low carbon grades, 7,300 tons of ferrosilicochrome and the rest is ferrosilicon (5,000 tons/year). Türkiye is one of leading ferrochrome producers in the world considering the above mentioned production figures. However, this production is mainly exported since Türkiye?s stainless steel production level is modest requiring low amounts of ferrochrome. The products of iron and steel industry in Türkiye require large quantities of other ferroalloys, which make Türkiye a major importer and exporter of ferroalloys. The aim of this work is to present production, consumption, import and export quantities of: ferrochrome, ferromanganese, ferrosilicon, ferromolybdenum, ferrotungsten, ferrotitanium and ferrovanadium of Türkiye, between 1990 and 2006.

Jan 1, 2007

By M. A. Reyes, L. Yan

Heat and humidity buildup withn refuge alternatives (RAs) may expose occupants to physiological hazards such as heat stress. The Mine Safety and Health Administration (MSHA) regulations require RAs in underground coal mines to provide a lifesustaining environment for miners trapped underground when escape is impossible. RAs are required to sustain life for 96 h while maintaining an apparent temperature (AT) below 95 °F (35 °C). The National Institute for Occupational Safety and Health (NIOSH) tested a 10-person tent-type RA, a 23-person tent-type RA, and a 6-person metal-type RA in its underground coal mine facilities to investigate the thermal environment over a 96-h period. The test results showed that mine air and mine strata temperatures surrounding an RA occupied by simulated miners (SMs) increased over the 96-h test period. The test results suggest that RA manufacturers should consider this increase in temperatures when calculating and evaluating RA components during surface and laboratory tests. The findings can equip stakeholders with additional considerations for calculating the interior heat and humidity temperature profiles for occupied RAs not tested in situ.

By Georgene Renner

At the beginning of the 1990s, Communism fell and signaled the end of the Cold War. The world rejoiced but also watched and waited to see how those countries would restructure themselves. The 1990 SME Annual Meeting was held at the Salt Palace Center in Salt Lake City, UT. The keynote session featured Alistair Frame, chairman of RTZ; Paul Queneau, professor of metallurgy at the University of Utah; and TS Ary, director of the U.S. Bureau of Mines. The SME Board of Directors voted to hire a Manager of Public Information and Education to be the GEM Program coordinator. This person was to collect and disseminate information that could be used by individual members and Local Sections to interface with government personnel and the general public.

Jan 1, 2007

By Alonso Marchena, William Martínez

El estudio que se ve reflejado en el presente artículo tuvo como objetivo mantener actualizado el mapa metalogenético del Perú y desarrollar conceptos sobre el origen de los yacimientos minerales, basados en datos geocronométricos, geoquímicos, isotópicos, estratigráficos y estructurales, en la Cordillera Occidental entre Ica y Tacna. La zona de investigación comprende las franjas metalogenéticas IV, V, VIII, IX y X. Se destaca el valor de herramientas tales como la litogeoquímica en la discriminación de pórfidos de Cu (Mo-Au) y se muestra la efectividad de nuevos parámetros de elementos traza en la discriminación y reconocimiento de magmatismo fértil vinculado a pórfidos en el sur del Perú.

Oct 30, 2020

By H. Lawrence

In 1977, the Bureau of Mines awarded a grant to the State of South Carolina to explore the possibility of using Landsat multispectral scanner (MSS) data as an aid in monitoring surface mining activities in selected counties of the State. Work had been done in Aiken County prior to the grant by Bureau of Mines and State personnel at the EROS Data Center using both the GE Image 100 and ESL IDIMS systems. The initial work on the 1-100 consisted of locating and measuring the areas of various kaolin mines. The results were excellent on location, identification, and accurate area measurements of several mines as compared with aerial photos of each mine. The effort also included locating and measuring the size of all mines (including sand and gravel) within two U.S. Geological Survey (USGS) 7 ½ min quadrangle maps. Line printer overlays using the IDIMS equipment and software resulted in the location of all known mines within an estimated error less than ±91.4m (5300 feet). Mine acreage was calculated by counting each symbol (which represented one pixel) and multiplying by 1.1 (the number of acres per pixel). Figure 1 shows a portion of one quadrangle overlay. Table I gives a comparison of acreage measured for sever- al mines from the 1-100 and IDIMS systems vs. aerial photo measurements.

Jan 1, 1979

Alluvial gold grades are typically highly erratic. It is very often difficult to establish with confidence the in situ grades of reserve blocks due to the small number of pit or drill hole samples available, and their erratic values. Trends in grade are often obscure. Geostatical methods are inappropriate due to the extreme nugget effect found in alluvial gold field data. Classical statistics appear more suited to such data but require assumptions to be made regarding the nature of the population sampled. Recent developments in computer intensive non-parametric statistical methods provide a new approach to dealing with some of the above problems. These methods avoid making assumptions about the type of population distribution, usually through some kind of re-sampling scheme. The bootstrap procedure involves taking the estimate of interest and synthesising its population of by re-sampling the original data a large number of times (1000+), at random and with replacement. The synthetic population is then used to draw conclusions about the likely behaviour of the true population.

Jan 1, 1985

By Manuel Arnáiz, Pedro R. Sola, Rogelio Baudot, Manuel Herrera, Carlos S. Oteo

The aim of this paper is to describe and analyze the ground treatment performed between January and May 2002 in order to increase safety during excavation and reduce instability problems along 180 m of tunnel, during the construction works associated with line 10 extension to the Madrid Metro. The tunnel was excavated using the traditional Madrid Method and in the section considered in this paper layers of sand were detected around the tunnel crown area with a significant presence of water, the in?ow of which needed to be controlled with a minimum impact on the surrounding environment.

Jan 1, 2003

By L. A. Ruth

Vision 21 is a government/industry/academia cost-shared partnership to develop the technology basis for integrated energy plants that will, early in the 21stcentury, result in the deployment of ultra-clean plants that produce electricity and “opportunity” products. Vision 21 plants will use fossil fuel feed-stocks in combination with other domestic resources, e.g., biomass, municipal waste, and petroleum coke. Opportunity products could include transportation fuels, steam, high-value chemicals, synthesis gas, and hydrogen. Performance targets for Vision 21 plants, example plant configurations, and the key technologies that will be needed are described.

Jan 1, 2000

By Robert F. Randolph, Christa L. Themann, Efrem R. Reeves, Thais C. Morata, Babette L. Verbsky, David C. Byrne

Objective: Workers with hearing loss face special problems, especially when working in noise. How­ever, conventional hearing conservation practices do not distinguish between workers with normal hearing versus impaired hearing. This study col­lected information from workers with self-reported noise exposure and hearing loss, supervisors of such workers, and hearing conservation program managers through focus groups and in-depth inter­views to evaluate their perspectives on the impact of hearing loss on safety and job performance, the use of hearing protection, and information needed to appropriately manage hearing-impaired workers who work in noisy environments. Results: Concerns about working in noise with a hearing loss could be grouped into the following 10 categories: impact on job performance, impact on job safety, impaired ability to hear warning signals, impaired ability to monitor equipment, interfer­ence with communication, stress and/or fatigue, impaired communication caused by hearing protec­tor use, reduced ability to monitor the environment as the result of hearing protector use, concerns about future quality of life, and concerns about future employability. Mostly, there was an agree­ment between the perceptions of workers, supervi­sors, and hearing conservation program managers regarding difficulties associated with hearing loss and consequent needs. These findings suggest that noise-exposed workers with hearing loss face many of the same problems reported in the literature by noise-exposed workers with normal hearing, with additional concerns primarily about job safety as the result of a reduced ability to hear environmental sounds, warning signals, and so forth. Conclusions: The study outlines potential chal­lenges regarding job safety and hearing conserva­tion practices for noise-exposed, hearing-impaired workers. Awareness of these issues is a necessary first step toward providing appropriate protective measures for noise-exposed, hearing-impaired workers. Of the 19 million adults in the United States with some degree of hearing trouble, nearly half are currently employed in the workforce (NCHS, 1994). More than 30 million US workers are exposed to hazardous noise levels, and noise-induced hearing loss is the most common occupational disease in the United States (NIOSH, 1996). Many workers incur their hearing losses during the first 5 to 10 yrs of employment (Rosler, 1994; Ward et al., 2000) and subsequently work the rest of their careers in an environment where noise and hearing loss interact to impair their ability to hear communication and other important signals. Workers with hearing loss who are exposed to hazardous noise levels present a dilemma to hearing loss preventionists. On the one hand, it is of great importance to ensure that their residual hearing is protected from the damaging effects of the noise to which they are exposed. On the other hand, how­ever, traditional hearing protectors serve to further “deafen” such workers, making communication more difficult and impairing the detection of environmen­tal sounds and warning signals. These workers have special needs that must be addressed. However, conventional hearing conservation practices do not distinguish between workers with normal versus impaired hearing; and, to date, no governmental or professional organization has developed specific guidelines or policies concerning the accommodation of noise-exposed, hearing-impaired workers. Some research regarding noise-exposed, hearing-impaired workers has been completed. These studies have primarily focused on three areas: (a) speech intelligibility in noise versus quiet, with and without various types of hearing protection devices (Abel et al., 1982; Abel et al., 1993; Abel & Spencer, 1997; Rink, 1979; Suter, 1989); (b) signal detection and localization under similar conditions (Abel et al., 1993; Abel et al., 1985; Abel & Hay, 1996); and (c) the use of hearing aids as hearing protectors (Berger, 1986; Dolan & Maurer, 1996; Hétu et al., 1992; Hétu et al., 1993). Research in these three areas has provided an initial framework for development of a management para­digm for these workers. However, each of these studies addressed a very specific research question, examining