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By Florian Häckel, Ulrich Schwarz-Schampera, Benjamin Bühring, Katja Schmidt, Dieter Garbe-Schönberg, KoschinskyM Andrea

"The Vanuatu island arc and its adjacent back-arc basins form part of the southern New Hebrides subduction system in the southwestern Pacific Ocean within a triangle defined by the Solomon Islands, New Caledonia and Fiji (Meffre & Crawford 2001). The back-arc region east of the volcanic front is characterized by three structural depressions namely Vate, Erromango, and Futuna (from N to S), also known as the Coriolis Troughs. Earlier studies of lava compositions reveal the occurrence of highly evolved alkali-rich dacites as well as ankaramite basalts within the individual troughs (McConachy et al. 2005).Here we present the first mineralogical and geochemical analyses of hydrothermal fluids and precipitates (sulfides, sulfates, Fe-oxyhydroxides), sediments, and volcanic rocks, sampled during the "Coriolis Volcanism and Vents" (COVOLVE) cruise SO229 in July 2013 aboard the German R/V Sonne. The samples were retrieved during several ROV Kiel 6000 dives directly from the newly discovered active vent sites at the neovolcanic Nifonea Ridge, and from multiple sites at water depths ranging between 200 to 2800 m within the Vate and Futuna Troughs as well as from the shallow water Epi Caldera NNE of the Coriolis Troughs (Fig. 1)."

Sep 1, 2014

This chapter presents proportionate mortality ratios (PMRs) derived from death certificate data in the National Occupational Mortality Surveillance (NOMS) database for the years 1986 through 1993. At the time this report was prepared, 1993 was the latest year for which data were available. Industry is classified under the 1980 U.S. Bureau of the Census classification system [Bureau of the Census 1982]; cause of death, under the International Classification of Diseases, Ninth Revision (ICD-9) [World Health Organization 1977]. A PMR of 100 indicates a mortality risk for a particular industry group that is similar to that for all industry groups combined. A PMR over 100 suggests a higher risk; a PMR under 100 suggests a lower risk. PMRs are subject to many factors that affect their reliability and validity and may not be comparable across populations with very different causes of death. An elevated PMR for a specified cause of death among an occupational or industry group may indicate a relationship between a work exposure and the cause of death specified. However, there are many limitations of PMRs as a measure of risk; they are most useful for generating hypotheses about exposure-disease relationships, which can then be tested in other studies. Selected PMRs are presented separately for males and females for coal mining, metal mining, nonmetallic mineral mining and quarrying (which includes nonmetal, stone, and sand and gravel), and for oil and gas extraction. All PMRs have been adjusted for age and race. In general, PMRs are presented only if the lower 95% confidence limit exceeded 100. If a PMR in an ICD-9 subcategory was above 100, however, the PMR for the larger category into which the subcategory falls is always presented and may be less than 100. PMRs can be expected to be elevated for conditions that have a high prevalence in particular occupational groups. PMRs showed elevated values for conditions known to affect miners, such as coal workers' pneumoconiosis, pneumoconiosis due to silica, tuberculosis, chronic pulmonary heart disease, and injuries. Additional findings of interest were- • An elevated PMR for myocardial infarction among male coal miners (table 2-1); • Elevated PMRs for neurologic disease in general and anterior horn cell disease, in particular among male metal miners (table 2-3); • An elevated PMR for rheumatic heart disease in male metal miners (table 2-3); • Elevated PMRs for malignant neoplasms of the digestive organs and peritoneum and for malignant neoplasms of the colon and rectum in female nonmetal miners (table 2-6); and • Elevated PMRs for non-A, non-B hepatitis and arteriosclerotic heart disease among male oil and gas workers (table 2-7).

Jan 5, 2000

By Met M. E, Worner H. K

During the past two years, a large number of creep tests has been carried out on electrolytic lead, special assay lead and ordinary refined (Port Pirie) lead. Some of these tests have already been reported.1§ In addition, an attempt has been made to estimate the influence of the individual elements present in small traces in Port Pirie lead. The present paper gives the results obtained when small additions are made to "U" lead of the composition shown in Table 1.(which has been used throughout these investigations during the past few years). The additions were silver, antimony, bismuth and zinc. The results of the addition of tellurium have already been communicated. This investigation was intended to run parallel with a similar one using electrolytic lead as a basis and adding one element at a time.Actually, the experiments using "U" lead have got rather ahead of the others. The important point has emerged, however, that the effect of a .given addition may be appreciably influenced by the presence of traces of other elements.In most of these tests, an initial stress of 500lb. per sq. in. has been used. Whilst it is fully appreciated that this stress is higher than those used in practice, it has to be borne in mind that an improvement in creep resistance was *Manuscript received December 11th, 1936.

Jan 1, 1936

By Adams F. C, Ridley K. L

Economic conditions after WorId War II made the recovery of Australian sources of sulphur one of considerable national importance. From 1947 to 1949 an investigation was made of recirculation techniques to produce acid plant grade gas from the Dwight-Lloyd down-draught sintering plant.During 1949 it appeared feasible to produce a gas of suitable 802 concentration and a decision was made to construct a gas purification train and a 150 tons/day contact acid plant. However, a number of difficulties remained in the production of the gases for sulphuric acid manufacture and as a result of research conducted to overcome these troubles the continuous up-draught sintering process was developed.The principal difficulties were:(a:) The down-draught sintering practice, as developed, produced an unusually high metallic lead precipitation in the windboxes. The disposal of this lead interrupted sintering operations and the delivery of gas to the acid plant.(b) The production capacity of the existing sintering plant was fully extended and the adoption of recirculation of gases, in an endeavour to satisfy acid plant requirements, would probably reduce the plant production capacity.(c) The prevailing high temperature of water available for purification train cooling required a higher than...

Jan 1, 1956

By Paul J. Sylvester, Yeonuk Choi, Mike Nelson, Louis J. Cabri, Mike Tubrett

"The development and characterization of sulphide standards containing as many as seven precious metals has increased the efficiency and comprehensiveness of micro-analyses for deportment studies using laser ablation microprobe inductively coupled plasma mass spectrometry (LAM-ICPMS). Because trace precious metals occurring in solid solution or as sub-micron inclusions in sulphides, arsenides, and sulpharsenides are often heterogeneously distributed, a significantly large number of analyses are required. Using well-prepared samples it is possible for up to 120 analyses per day, far more than by other comparable methods. Examples will be discussed from projects focused on the deportment of Au and the platinum group elements (PGE).INTRODUCTIONBecause gold and the platinum-group elements (PGE) occur as both discrete minerals and in trace quantities in a variety of minerals (mostly sulphide, arsenide, and sulpharsenide minerals), specialized trace analytical methods were developed and applied to determine the deportment of precious metals in ore deposits, requiring sensitivities ranging originally from about hundreds to presently tens of ppb for individual precious metal or less.In mineralogical studies, micro-analytical techniques such as the electron microprobe were first applied to obtain analyses for major elements in about 1959-60, but as the instrumentation improved early attempts for PGE in potential carrier minerals indicated that reasonable levels of detection (LOD) were of the order of 300-400 ppm, depending on analytical conditions, X-ray spectral lines, and mineral matrix (e.g., Cabri and Laflamme, 1976). Eventually, the lowest detection levels by electron probe micro-analyses (EPMA) obtained for some PGE were of the order of 10s of ppm using high accelerating voltage and current for extended measuring time on peak and background (Gervilla, Cabri, Kojonen, Oberthür, Weiser, Johanson, Sie, Campbell, Teesdale and Laflamme, 2004)."

Jan 1, 2010

By J. Kern, T. F. Torries

Identifying high value areas of unmined coal when large quantities of coal are available relative to annual markets is difficult because of the uncertainty of when the coal is to be mined. A GIS based methodology developed to value reserve coal in a producing coal region for the purpose of ad valorem taxation also identifies high value areas for mining investment. The methodology is unique in that it accounts for most mining, environmental, and market factors to determine when specific properties are to be mined. The methodology and data base are useful for directing regional exploration and acquisition activities toward most favorable areas.

Jan 1, 1999

THE Synthetic Liquid Fuels Act. (30 U.S.C., 321-325, and amendments) became law April 5, 1944, and a period of intensive research and development in this field was begun by the Bureau of Mines. As part of this program, bulletins were published on pressure hydrogenation.3 the Fischer-Tropsch synthesis,4 anal oil shale.5 The Bureau also has published a short bibliography on coal gasification,6 mostly of a theoretical nature. Because coal gasification is prerequisite to either the Fischer-Tropsch or coal-hydrogenation processes, publishing this sizable collection of technical information in this form will be valuable. The material will be presented in three parts, as follows: I. United States Patents. II. United Kingdom Patents. III. Other Foreign Patents. The domestic patents for this bulletin were collected between 1953 and 1955.

Jan 1, 1960

By Paul N. Freeman

This paper describes the in-situ performance of two IFS powered support installations at Betws and Penallta Collieries in the South Wales Coalfield, United Kingdom. Intensive monitoring of all powered support functions, strata movement, support/strata interaction and coal seam disturbance permitted an extensive evaluation of powered support performance for all periods of the mining cycle. The influence of support design, support rating, face design, proximate strata and scam section upon support and operating performance are discussed. In-situ performance is compared to design specification and to the requirements of Production Instruction 1982/6. Aspects which show significant variation are highlighted. Particular attention is drawn to the precise analysis of support/strata interaction in the form of canopy and base loading profiles. This illustrates the influence of support rating and configuration in determining the interaction of the canopy and base with the proximate strata. Extensometric monitoring of the coalface highlights the potential zones of disturbance within the seam which allied with support position monitoring provides an accurate basis for theoretical considerations of support loading. Conclusions are drawn, the application of which may enhance the performance and operation of IFS supports in thin to medium sections.

Jan 1, 1992

By Joe Zhou

"Mineralogical characterization and metallurgical extraction of silver is challenging due to its complex mineralogy and chemistry. Over 200 Ag-bearing minerals have been identified and a silver-rich ore body would typically contain 5 to 10 different silver minerals. Silver can occur not only as discrete microscopic (visible) silver minerals but also as submicroscopic (invisible) silver in other minerals. During processing, silver may form passivation compounds such as silver hydroxide, silver sulphide, jarosite-like silver sulphate, silver halide or silver cyanide precipitate, all of which may negatively impact on silver extraction. Knowing the deportment of silver in the ore and its metallurgical products is important in flowsheet design and plant optimization. This paper begins with the classification of silver ores and minerals and a review of processing techniques, and focuses on the major mineralogical factors to explain why and how these factors affect silver extraction. Case studies are provided to demonstrate the application of silver process mineralogy in flowsheet design and plant optimization.INTRODUCTIONSilver was known to and utilized by mankind since ancient time. Actually, it was one of the earliest metals discovered and utilized by mankind after gold and copper.Silver is the whitest metallic element. It is rare, strong, corrosion resistant, and unaffected by moisture, vegetable acids, or alkalis. Silver is also resonant, moldable, malleable, and possesses the highest thermal and electric conductivity of any substance. The chemical symbol for silver is Ag, from the Latin argentum, which means white and shining. Although silver does not react with many chemicals, it does react with sulfur, which is always present in air at trace amounts. The reaction causes silver to tarnish, and consequently it must be polished periodically to retain its luster.Silver possesses many special physical characteristics and qualities that make it useful to a variety of industries. The photography industry is the biggest user of silver compounds. Silver forms the most light-sensitive halide salts, which are essential to developing highquality photographic prints. Silver also has the highest electrical conductivity per unit volume of any metal, including copper, so it is used extensively in electronics."

Jan 1, 2010

By Richard F. Sliwoski

The Virginia State Capitol was designed by Thomas Jefferson and constructed in 1785. The Capitol is of great historic and architectural significance to not only the Commonwealth of Virginia but to the nation. It is the oldest operating Capitol in the U.S. and required a total restoration/renovation as well as an expansion to continue to remain functional. Site conditions dictated that the expansion (a new visitor center) be placed underground on the south side of the Capitol building, requiring a 40-foot deep excavation approximately 5 feet from the Building. Because of its historic significance, every measure had to be taken to ensure the safety and function of the Capitol during construction. The construction techniques that were used to make the deep excavation and protect the historic Capitol included a tied back concrete slurry wall, jet grouting, compensation grouting, and instrumentation monitoring. This paper describes the history of the Capitol building, the techniques that were employed for construction of the deep excavation, results of the latest movement monitoring, and factors contributing to meeting the restrictive movement goals.

Jan 1, 2006

The range of environments which control the level of ground support required vary greatly in terms of rock type, rock structure and the mining method used. At the operating mines visited during this review the level of ground support was such that incidence of rock-fall- related accidents were rare. It was also found that methods existed to support most of the conditions encountered. The main problem areas were weak rock, major geological structures, areas of heavy jointing, high development density and areas affected by high mining-induced stresses and blasting. With stope support the level of success was much lower than that achieved in development; the larger spans and more rapid changes in geometry of open stopes compared with cut and fill stoping (where cables were originally used) led to significant problems. Before a useable design method for cable support of stope walls and pillars can be obtained the precise failure mode of the walls and pillars, and the interaction of the support and the rock mass must be investigated.

Jan 1, 1982

By H. Walqui

The Empire concentrator was built in four stages, with the latest stage accounting for 50% of the overall plant capacity. Over the past 5 years, the average throughput of the three grinding lines has decreased by 50 LTPH (15%) without significant changes in ore characteristics and despite the addition of secondary grinding capacity to supplement the existing pebble mills that are the constraint of the grinding circuit. This paper discusses the different areas under study that are aimed at optimizing grinding circuit utilization which includes improving system logic, pebble crushing operation and pebble mills operation.

Jan 1, 2009

By Christoph Müller

Information exchange for mine process optimization is essential. Today, modern mining equipment uses the IREDES standard to exchange production plans and reports for easy management and storage. To gain further benefits from process optimization, a mine wide access to real-time information is needed as e.g.: The current status of a machine, operational details etc. Presently, real-time data exchange systems are developed by machine producers. Each machine producer uses its own way of gathering, managing, and storing production data. These proprietary mining processes increase the complexity of cross platform data exchange and management for mines which involves machines produced by different vendors. Casting and unifying the data requires much effort. For this purpose, ?IREDES On-line? currently is being introduced. The standard defines an open, web based method for the exchange of volatile real time machine information. Two different principles are used: Web Services for cross platform information exchange within the IT world and the optional OPC UA for use with automation and process control systems. With such a standard information from machines of different vendors may be managed by using one common platform without spending the effort for dedicated interface development. Additionally, information management and storage will become straight forward since all the data are of the same format. The IREDES On-line standard utilizes the latest IT technologies as well as the knowledge and experiences gained from the previous IREDES standard. The paper explains the benefits, the use, as well as the technical design of the standard and gives application examples from the practice.

Oct 1, 2009

By Michael Young, Josh Rubenstein, Michael Cooper, Tom Shouldice, Dan Curry

"Xstrata Nickel Australasia’s Cosmos plant in Western Australia is currently implementing a debottlenecking project to increase nickel output while maintaining metallurgical performance and a low unit cost for production. Mineralogical analyses indicated that the processing bottlenecks could be removed by simply reconfiguring portions of the circuit as well as adding capacity with technical advancements – notably an IsaMill™, Jameson Cell, Wemco® SmartCell™ and Larox Filter.The Wemco® SmartCell™, which is particularly suited for coarse mineral flotation, and Jameson Cell, which is particularly well suited for fast floating and fine minerals, combine as rougher scalpers to complete the main stream portion of the flotation circuit. Addition of the two new cells meet the required flotation capacity to handle the forecast increase in nickel feed grade and tonnage.The addition of an IsaMill™ for regrinding allows the SAG mill to produce a coarser primary product, thus enabling increased throughput. The advantages offered by the IsaMill™ include operation in open circuit (internal classification), an inert grinding environment (ceramic media) for better downstream flotation (“clean” new surfaces), compact footprint (easy to retrofit into existing plant) and energy efficiency. With the new rougher capacity addition, the remaining original plant cells were reconfigured to suit the new regrind mill and cleaning requirements. The existing 24 m2 Larox pressure filter was replaced with a larger 32 m2 unit to dewater the increased concentrate output.The paper describes the upgrade at the Cosmos concentrator with particular emphasis on the mineralogical data and metallurgical benefits associated with the changes.INTRODUCTIONThe Cosmos concentrator is located 680 km northeast of Perth in Western Australia. The deposit’s development and operations were started in 1999 by Jubilee Mines NL, Cosmos’ previous owner, with the first production of nickel concentrate in April 2000. The Cosmos concentrator treats a komatiite hosted high grade nickel sulphide ore, with sulphides being predominantly pentlandite and pyrrhotite with lesser amounts of pyrite and chalcopyrite."

Jan 1, 2010

By S. Ilyas

Technical innovation in electrical and electronic equipment with new functions and design, stimulate consumer?s purchasing desire towards the latest equipments and this leads the rapid increase in the production of increased amount of waste materials Treason et al (2006) have reviewed the data on electronic waste generation in different parts of the world. Studies by Bertram et al (2002) have also affirmed that waste electrical and electronic components are the fastest growing waste category; this emphasizes the need for efficient recycling strategies. Recycling of electronic waste is an important subject not only from the point of waste treatment but also from the recovery aspect of valuable materials. However, recycling of electronic scrap is still quite limited due to the heterogeneity of the materials present in the products (Veit et al. 2005). A bioleaching based process offers a number of advantages compared to the conventional pyro or hydrometallurgical methods (Lee et al. 2007; Lee and Pandey, 2012). The advantages include simple, inexpensive (in some cases) and eco-friendly approach besides, generation of less active leach residue then other metallurgical processes. Though, biohydrometallurgical process has been successfully applied for the leaching of metals from ores (Olson et al. 2003; Rawling 2000), data pertaining to its application for the extraction of electronic scrap is still scanty. Recently, a few studies have been undertaken for extraction of metals from electronic scrap/printed circuit boards (Brandl et al. 2001; Faramarzi et al. 2004; Choi et al. 2004, Ilyas et al. 2007; Ilyas et al. 2010). These studies were conducted with mesophilic chemolithotrophic (Acidithiobacillus ferooxidans and Acidithiobacillus thiooxidans) or cyanogenic bacteria (Chromobacterium violaceum) or moderate thermophilic bacteria (Sulfobacillus thermosulfidooxidans). However, compared to bacterial leaching, fungal leaching has the following advantages: (i) ability to grow under higher pH, and thus is more suitable in bioleaching of alkaline solid waste (ii) a generally faster leaching process with shorter lag phase (iii) Chelation of excreted metabolites (e.g. organic acids) with metal ion, thus reduce its toxicity to the biomass (Burgstaller et al. 1993; Aung and Ting 2005). The specific objective of this work was to; ? Collection, isolation and enrichment of fungal strain ? Evaluate the abilities of Penicillium chrysogenum to leach metals from electronic scrap at various leaching modes (one-step bioleaching, two-step bioleaching, spent medium leaching, fresh medium leaching, leaching with deionised water and chemical leaching). ? Comparative study of all leaching modes

Feb 27, 2013

By Christian Ottergren

"Modern crushers offer double the capacity and performance of classic models. In some cases crushers are replacing SAG circuits, the advantages being smaller investment and lower operating costs. Is Tertiary crushing replacing SAG milling as the most optimal grinding method? Does tertiary crushing achieve the same outcomes as SAG milling? This paper considers these questions and provides an assessment of the strengths of tertiary crushing in comparison to other methods. Two case studies: a Scandinavian Platinum Project, and CODELCO, are also presented.INTRODUCTIONResearch on basic parameters in crushing started at Chalmers University in 1993. The initial project has developed and now involves several related areas. Modelling in accordance with new theories has resulted in modified designs which have been implemented and shown improved performance at operating mines in Chile. Sandvik Rock Processing is a partner and a major supporter of this program. This paper will cover some of the achievements and give references to the research reports.The mining industry has for many years mainly used crushers of the traditional 7’crusher concept, with thread adjustment of the setting and with a spring or hydraulic overload system. This machine type has been the workhorse for crushing throughout the world. The explanation for the dominance of this machine is that it has a reliable mechanical design. It can be estimated that about 2000 crushers of this design are still at work.Technical development in all fields utilizes new technologies like high-strength materials, advanced control systems and more extensive use of hydraulics. This is the reason why today’s motorcars, for example, are more efficient, more reliable and more environmentally friendly than their predecessors in the 1950s. Crushers are no exception. This paper will cover experience from the latest-generation cone crushers developed by Sandvik Rock Processing.The parts in this paper related to the CODELCO ElTeniente copper mine in Chile are coauthored with responsible personnel from the operation at the mine."

Jan 1, 2004

By Rodrigo Toro, Ivan Yutronic N

"The Copper Concentrator Plant of Compañía Minera Doña Inés de Collahuasi (CMDIC) is composed of three grinding lines, the third one being the largest. Due to the capacity feature of the third line, specially its SAG mill, it is a priority that the advanced process control team of the Company deploys a supervisory control strategy that allows this unit to operate in an optimal way, in order to achieve the maximum productivity at minimum cost. It is in this kind of tasks where advanced control applications play a key role in obtaining the best economic profit of the process.The advanced process control team, formed by people from Informatics, Automation and Operations of CMDIC have assumed the challenge of generating the transition from a manual SAG Mill 1011 operation (40 x 22 feet, the largest copper SAG mill of the world), to a fully automatic SAG Mill using a multivariable control strategy instead of a rule based on expert control system (widely used in industrial mining process control applications).Therefore, CMDIC decided to work together with Honeywell APC Team implementing an advanced automatic control strategy for the SAG Mill 1011, using for this purpose a technology called Model Based Predictive Control (MPC), based on a variety of control methods that uses dynamical models of the process, obtained from input/output data, in order to print the process knowledge into a group of mathematical relationships that links the constraints (controlled variables) with available commands (manipulated variables) and measured disturbances.The main objective of the advanced control strategy is to ensure process government, tending to throughput stability and optimization, by the execution of coordinated control actions, proactively avoiding measured disturbances effects and the SAG mill overloading.The most important benefits of using a multivariable control strategy are: the automated operation of SAG mill 1011 (that was manually operated before the implementation of this application), a safer, more coordinated and more stable process operation, achieving through this an increase of throughput and a decrease of specific energy consumption, controlling the amount of oversize material production, power consumption, mill loading, noise and torque. In addition to the operational results, this challenge has consolidated a control team, with the participation of engineers and operators, diminishing the typical implementation time and achieving a greater use of the application in a short time."

Jan 1, 2010

By AIME AIME

GENERAL COMMITTEES. SAN FRANCISCO:-ExECUTIVE, Hon. William C. Ralston, Chairman; RECEPTION, Prow. Samuel B. Christy, Chairman; SESSIONS, Frederic W. Bradley, Chairman; PRESS, H. Foster Bain, Chairman; FINANCE, Mark L. Requa, Chairman; EXCURSIONS AND ENTERTAINMENTS, Edward H. Benjamin, Chairman. Assisted by Harry P. Stow, C. W.Merrill, F. W. Griffin, Gelasio Caetani, Albert Burch, Newton Cleaveland, Corey C. Brayton and R. E. Cranston. Los ANGELES :-EXECUTIVE, Theo. B. Comstock, Chairman; R. W. Hadden, Secretary; H. R. Simpson, Treasurer. Institute Headquarters at Hotel St. Francis. The first and opening session, held Tuesday afternoon, Oct. 10,. in the Reception-Hall of the St. Francis, was called to order by State Senator William C. Ralston, Chairman of the Executive Committee, who in a few well-chosen words welcomed the visiting members and guests of the Institute to San Francisco. He said it was twelve years since the last meeting on the Pacific Coast and that it was here that the greatest feats. of mining had been accomplished in the history of the country. He told of the work that had been done on the continent and of the new methods introduced by the mining engineers for the betterment of the nation. He then introduced Capt. Robert W. Hunt, twice past President of the Institute, and present Acting President for the San Francisco meeting and the subsequent visit to Japan, who responded cordially to Mr. Ralston's welcoming address. By unanimous vote, the Secretary was instructed to send a telegram to President Charles Kirchhoff expressing regret for his absence, and hoping for a rapid improvement in the health of his mother. The following papers were presented in brief oral abstract by the authors: . * Electrolytic Refining at the U. S. Mint, San Francisco, Cal., by Edward B. Durham, San Francisco, Cal. The Parral Tank System of Agitating Slime-Pulp, by Bernard MacDonald, Guanajuato, Mexico. * The Newport Iron-Mine, Ironwood, Mich., by B. W. Vallat, Ironwood, Mich. (illustrated by lantern-slides). * Distributed in pamphlet worm.

Nov 1, 1911

By R. F. Kehrman

Voice Frequency (VF) electromagnetic trapped miner location devices were tested for reliability and effectiveness in 93 coal mines. Tests included uplink pulsed CW, downlink pulsed OW and downlink voice evaluations. Frequencies were 630, 1050, 1950 and 3030 Hertz. Overburden depths varied from 70 feet to 1550 feet. Successful communications were established at 91 of the 93 mines. Data indicate the transmitters and receivers will operate in practically all coal mine environments. Reliability and accuracy as location devices appear to depend on noise, depth and presence of metallic objects which distort the magnetic field. In addition, theoretical models appear to define best case situations in terms of noise and conductivity. Minor hardware problems were encountered, mostly involving battery contacts, switches and antenna cables on the receivers. No hardware problems occurred with the transmitters.

Jan 1, 1978

By James E. Hill

Tremendous improvements in mining technology have been witnessed during the past 100 years. For example, before 1860 all blastholes were drilled manually and blasting was done with low-energy black-powder. During the 1860's both the pneumatic rock drill and high-energy dynamite were introduced, ushering in an era of mining mechanization that has steadily progressed since that time. Today, with the rapid implementation of the latest advances in communication science, mining technology is moving into a new era that goes beyond mechanization as such. Transistors, transducers, scanners, telemetry, and the like, all terms largely derived from the new communication sciences, add up to what is popularly know as automation-the communication of machine with machine. Automation is now playing an important role in selected parts of the mining process, such as hoisting, hydraulic roof supports, and underground surface locomotive haulage and belt conveyor systems. But this year marked the first attempt to auto-mate the total mining process with the commencement of production at the British National Coal Boards Bevercotes mine. If this full-scale experiment proves successful, it could lead towards other fully automated mines in both Britain and other parts of the world. This decade, there-fore, could be considered the one that provided the foundation for the mines of the future.

Jan 1, 1966