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By Robert L. Lagace, Michael A. Grossman, Alfred G. Emslie

This supplement to the final report is a collection of interim and monthly reports and working memoranda prepared during the course of this program to document the progress, methods and results of the work. The supplement is divided into the self-contained sections briefly described below. I. SELECTED MONTHLY TECHNICAL LETTER REPORTS - This section is a collection of selected monthly technical letter reports that briefly summarizes the chronological development of the analyses and results, including the different concepts, theoretical approaches, and methods of data reduction and analysis explored, and the discoveries, insights and findings made along the way. More detailed treatments of the key developments and results are presented in the interim reports and working memoranda reproduced in subsequent sections of this supplementary report, and in the separately published final report. II. BACKGROUND THEORY FOR MEASUREMENT PROGRAM ON MEDIUM AND HIGH FREQUENCY RADIO TRANSMISSION IN COAL SEAMS - Working Memorandum - This working memorandum gives the initial background theory needed to guide the planned measurements and data analyses of this program to describe the propagation of radio waves-in coal seams for the frequency range of 50 to 5000 kHz. III. MODELLING AND DATA ANALYSIS OF IN-MINE ELECTROMAGNETIC WAVE PROPAGATION - Interim Report - This interim report presents detailed treatments of the data analysis and modelling techniques used, and the associated results obtained from conductor-free area propagation data measured by T. Cory in the first set of six coal mines. The mines were located in three highcoal seams; the Pittsburgh seam in northern West Virginia, the Pocahontas No. 3 seam in Virginia, and the Herrin No. 6 seam in Illinois. IV. ANALYSIS OF MF PROPAGATION DATA FROM MARGARET NO. 11, NANTY GLO, EHRENFELD, AND ADRIAN COAL MINES - Interim Report - This interim report presents detailed treatments of several improved data analysis and Modelling methods applied to, and results obtained from, conductor-free area propagation data measured by T. Cory in the second set of four coal mines. These mines were located in three low-coal seams; the Upper Freeport seam in Pennsylvania and West Virginia and the Lower Freeport and Lower Kittaning seams in Pennsylvania. In addition, this report contains a reprint of two papers presented at a Bureau of Mines sponsored EM Guided Waves in Mine Environments Workshop held in Boulder Colorado. One paper describes the three-layer theoretical model and its application to the conductor-free data from the first six mines, while the second paper describes the theory developed for the coupling of loop antennas to a cable in a mine tunnel in a coal seam, and the model's application to data in the vicinity of cables taken at the Margaret No. 11 mine. V. A METHOD FOR NONINTRUSIVE, IN-SITU MEASUREMENT OF COAL AND ROCK CONDUCTIVITIES IN A COAL MINE TUNNEL - Working Memorandum - This working memorandum briefly describes a possible direct method, and its potential advantages and shortcomings, for performing in-situ measurements of coal and rock conductivities. VI. MODELLING AND DATA ANALYSIS OF IN-MINE ELECTROMAGNETIC WAVE PROPAGATION FROM 50 to 5000 kHz - Interim Report - This interim report presents a summary comparison of theoretical and experimental results for conductor- free areas in eleven coal mines located in seven coal seams. It also summarizes the findings and their implications for intrinsically-safe, portable radio communications between roving miners.

Jan 2, 1980

By D. L. Yopps

Platinum-group metal (PGM) flotation .. concentrate from the Stillwater Complex, MT, was subjected to biooxidation using Thiobacillus ferrooxidans in an effort to break down the sulfide minerals and liberate the ? associated PGM's for subsequent chemical leaching. Bacterial treatment oxidized up to 94 pct of the sulfide present, destroyed the PGM-bearing pentlandite [ (Ni,Fe),9Ss) mineralization, and dissolved most of the nickel in the concentrate. Results showed that increased sulfide oxidation during the biological stage led to improved PGH recovery in the subsequent. chemical leaching stage. cyanidation at 80° c proved to be the best chemical leachant tested. It removed 7.6 pct of the palladium, 94 pct of the rhodium, 97 pct of the gold, but only 34 pct of the platinum from the biooxidized concentrate.

Jan 1, 1991

By R. Patterson

Tracer gases have been utilized successfully in a variety of industries, each with specific releasing and sampling methods. The various attributes of tracer gases are dependent on the industry the tracers are utilized in. Tracers must be chemically and thermally stable, safe, odorless, detectable at low concentrations, have a low background concentration, and should not be naturally occurring in the environment if they are utilized in underground mining applications (Thimons et al., 1974). In addition, the tracer gas should be inexpensive, non-corrosive, non-toxic, easily transportable, readily attainable, and non-radioactive (Kennedy et al., 1987). Sulfur hexafluoride (SF6) met many of these above requirements and therefore was introduced as an ideal tracer gas to use in mining industry in the early 1970?s (Thimons et al., 1974). Due to the nature of underground mining including complicated geometry, irregular flows, turbulent flows, obstructed airways, and leakages it is difficult to use conventional anemometer and smoke tube techniques to accurately measure the effectiveness of ventilation controls (Thimons et al., 1974; Klinowski and Kennedy, 1991). There have been several applications of SF6 as a tracer gas in underground metal/non-metal and coal mines. Thimons et al. conducted early testing of SF6 in an underground limestone mine and determined that it is an effective technique for evaluating auxiliary fans, estimating volumetric flow rates in large areas, and measuring low flow velocities. A rapid face ventilation measurement method (FVM) utilizing SF6 was developed by the Bureau of Mines to make face measurements in underground coal mines (Timko and Thimons, 1982). When measuring the effectiveness of jet fans in dead headings SF6 was proven more effective than smoke tubes (Timko and Thimons, 1982). Experiments related to determining methane liberation in the gob were also conducted by injecting SF6 into a borehole (Timko and Thimons, 1982). Also, in an emergency situation where the gob had to be sealed due to a fire, SF6 was released to determine the effectiveness of the seals (Timko and Thimons, 1982).

Jan 1, 2011

By E. D. Gardner

IN 1947 the metal-mining industry . passed through a year of readjustment; catching up on development work has caused production to suffer. Skilled labor has been short in most mining districts, notwithstanding the highest wage rate paid in the history of the industry. The trend has continued toward increased mechanization and refinements in practices and methods to increase the tons produced per man-shift. Improvements in procedures, however, have not kept pace with rising labor rates; and, in general, labor costs per ton mined have steadily increased since the war years. Prices of base metals have been the highest in a generation, but most producing companies can afford to pay the high wages. Capital expenditures have been approved for improvements to increase the output per man, both to reduce unit labor costs and to increase output. Surveys indicate a continuing

Jan 1, 1948

In November 1986 the Australian Minerals and Energy Council (AMEC) endorsed an "Australian Code for Reporting Identified Coal Resources and Reserves" for use by the Federal and all State Governments. Before this endorsement there were six different coal codes in use in Australia. The code is broad in nature to accommodate the wide range of coal deposits in terms of rank, quality and geological environment, that are present in Australia. In the code, Resources refer to all of the coal in situ which may have potential for use and the various categories indicate the level of confidence of the assessment. Reserves are those Resources which are planned to be mined and for which such planning has been undertaken. Only minimum guidelines are set by the code and the onus is on the estimator to state clearly the criteria used in any Assessment.

Jan 1, 1987

By A Palynchuk

The development of welded pipe has paralleled the general industrial development and, in particular, that of the petroleum industry. The petroleum industry's need for high-grade, economical pipeline material to make many 'of its projects feasible has been a significant factor in the development of light-wall, high-grade welded pipe. The modern welding processes, such as high-frequency, electric resistance, flash, submerged arc, etc., have some basically different characteristics. The modern high-frequency weld mill is a complex of specialized equipment that is integrated into a production unit. Each component in the unit performs a specific function in the production process. Quality control must be built into the process on an operating basis and, to maintain the quality required for pipeline standards, must be more than a policing operation. The further development of the welded pipe industry will be determined by changing and increasing demands. The technical and economic views and requirements that will influence the development have to be resolved.

Jan 1, 1964

By Geraldo Lúcio de Faria

O sucesso do transporte ferroviário depende, entre outras coisas, da integridade física dos componentes metálicos empregados na via permanente. Um dos mais importantes é o trilho, pois falhas catastróficas deste componente podem gerar graves acidentes. No intuito de desenvolver aços com bom desempenho para esta aplicação, estudos têm sido desenvolvidos para se entender os efeitos de composição química e histórico de processamento termomecânico sobre a microestrutura e propriedades mecânicas dos aços. Neste contexto, este trabalho caracterizou microestruturalmente dois aços de aplicação ferroviária, sendo um Standard e um Premium. Amostras representativas destes aços foram submetidas a ensaios dilatométricos e a cinética de transformação de fases austenita-perlita foi investigada. Por meio dos resultados obtidos, foi possível concluir que o aço Premium estudado possui microestrutura mais refinada e que este efeito é devido, principalmente, à menor concentração de Mn em sua composição química. O menor teor de Mn facilita a nucleação de cementita eutetóide, possibilitando a formação de perlita em tempos mais curtos e temperaturas mais baixas do que no aço Standard. Isto possibilita que o aço Premium, em seu processo de fabricação, possa ser resfriado a taxas mais elevadas do que o Standard sem formação de martensita, justificando sua estrutura mais refinada.

Aug 17, 2017

Jan 1, 1968

By Alexandre de Aparecida Morais

No processo de lingotamento contínuo a secagem e o pré-aquecimento do refratário do distribuidor são de fundamental importância. Estes são realizados visando: reduzir a perda de calor do aço líquido, reduzir as bolhas nas primeiras placas, evitar respingos de aço (reações) ocasionados pela umidade e prevenir a degradação refratário por choque térmico. Para aços planos, os sistemas para promover a secagem e pré-aquecimento podem ser do tipo a "quente" (mais usual) ou a "frio". É denominado "partida a quente" quando se realiza a secagem e o pré-aquecimento; e de “partida a frio”, quando apenas a secagem é realizada. Têm-se como características distintas entre os processos: - A Quente: maior consumo de gás; forte degradação do refratário; temperatura de trabalho do distribuidor mais elevada, deteriorando as condições do ambiente; - A Frio: menor consumo de gás; redução da degradação do refratário; no entanto, exige um controle rigoroso da curva de secagem, o que implica maior investimento inicial no equipamento de secagem. Em 2002, após uma análise de viabilidades a ArcelorMittal Tubarão implementou o sistema de frio. Este artigo mostra a evolução deste sistema após a sua implementação, analisando a correlação com defeitos, a implementação de melhorias e os ganhos obtidos.

Jul 30, 2018

By Yael Miron

Two recent unplanned detonations occurred during blasting operations in sulfide-bearing ores in a Nevada gold mine. Other premature detonations have also reportedly occurred at other Nevada, California, and Arizona operations within the past few years, with increasing frequency. Unplanned or premature detonations can be extremely hazardous to life and can cause extensive property damage. A miner was injured in one of these occurrences. This report, by the U.S. Bureau of Mines, is intended to acquaint personnel involved in such mining activities with the basic causes for these accidents. These causes include the exothermic oxidation of pyrite (FeS2) and formation of ferrous sulfate (FeS04), the exothermic and energetic reaction of the ferrous sulfate with ammonium nitrate-fuel oil (ANFO)-based explosives, and the associated elevated temperatures that can set off detonators and explosives in the boreholes. Recommendations for safe operation by the Mine Safety and Health Administration, the Bureau, and the mine involved with the recent incidents include monitoring temperatures in the blast holes, analyzing for sulfate and ferrous ions, and limiting the time between loading and firing in accordance with conditions in the blast holes. Other procedures for safe operations should fit specific conditions in, the mines.

Jan 1, 1992

By Leopoldo Gutierrez

Eight oil sand ores with the bitumen content ranging between 3.6 and 15 wt.% and the fines content (-44 micrometers size fraction) between 9 and 69 vol.% were subjected to the standard alkali extraction test used to measure the degree of oxidation of metallurgical coals. The results showed that there is a strong correlation between the absorbance of extracted solutions at a wavelength of 520 nm and the ratio of the fines content to the bitumen content. The latter factor is directly relevant to assessing the extractability of bitumen from oil sand ores. Bitumen extraction tests showed that the bitumen recovery decreased from 90 % to 30 % when the absorbance at 520 nm increased from 0.23 to 0.64. A comparison of the UV/visible spectra of solutions obtained from the alkali extraction tests with solutions of Aldrich Humic Acids suggest that low bitumen/high fines oil sand ores release substantial amounts of organic matter very similar, if not identical, to humic acids. In contrast, high-bitumen and low-fines ores do not release as much of the organic matter, and UV spectra of these leached substances are quite different from those of humic acids. Overall, the results show that chemical composition of bitumen in the tested ores varies greatly with ore type and oxidation, and that the alkali extraction test is a promising technique to quickly assess the extractability of bitumen from a given ore type.

Sep 1, 2012

By Joseph H. White

In its investigations looking to the improvement of health condi- tions and the increase of efficiency in the mining industry, the Bureau of Mines, in cooperation with the Bureau of Public Health, is studying sanitary conditions in and about mines with the intent of pointing out how those conditions that are a menace to the health of the miner may be most efficiently removed or remedied. An out- line of sanitary betterment work at mining villages in the Birming- ham district of Alabama has already been published by the bureau," and in this bulletin are presented suggestions on the planning of mining towns and the construction of miners' houses. The bulletin does not pretend to be a treatise on the so-called "housing problem," and mentions sociologic issues only incidentally. It is assumed that the influence of proper shelter on health is understood and that not a lack of appreciation so much as a lack of knowledge of the best remedies is responsible for many of the undesirable conditions that exist at mining towns. The purpose of this bulletin is to supply facts on the building of well-lighted, well- ventilated, warm, attractive, and economical houses for miners, these houses being assumed to be units of an industrial village or town the building and management of which are under the control of a corporation, so that special conditions hold which do not apply to houses built and owned by individual miners. From this it is not to be inferred that the company-controlled town is the best system or the only one in vogue. The discussion of this side of the subject in all its phases is too involved to be included in this paper. One element in favor of the company-controlled town is its possible immediate responsiveness. Hence this assumption. Also the assumption is made that a-new isolated town is being built, and hence the selection of the site, the arrangement of the streets, and the situation of the houses are discussed before the house itself is treated, for one of the most important factors in obtaining an economical sanitary house is a well-selected town site. Many of the suggestions, however, may be applied in improving conditions in existing towns, in building new houses in old towns, or in repairing old houses. Emphasis must be laid on the fact that as a rule a mining village has a shorter life than a manufacturing town. Economy is emphasized frequently because the discussion is predi- cated upon the assumption that the miner himself is to pay for all that he gets. House rent will doubtless be expected to bring in a reasonable return on all money invested in streets, sidewalks, water supply, sewer system, and houses; in other words, the town is to be run on a business and not on a paternal or charitable basis. "Fair and reasonable" precludes, of course, the idea of excessive returns. Some companies do not consider it good policy to realize as high a rate of interest as an independent realty company would be war- ranted in realizing. Under some circumstances part of the town improvements might be charged as "expense of the industry," that is, to the consumer. The isolation of a mining town introduces a unique responsibility. As the miners are practically obliged to rent the company houses, the officials of the company ought to scrutinize all expenditures in- volved so that house rent may be reduced to a minimum. In a way the town builders are placed in the position of trustees. They deter- mine, within certain limits, what proportion of a man's wages shall be spent on house rent. This consideration should restrain fanciful and unnecessarily expensive building; the other extreme should like- wise be avoided. True economy should be distinguished from cheap- ness. Ugly, insanitary, uncomfortable shacks should not be built even if, because of their cheapness, there is a demand for them from tenants. The obligation of the industry to society as a whole as well us to the tenant ought to forbid this. A cheerful, strong, healthy, virile race will not rise out of the filth and squalor of cheap hovels. An insanitary environment often does its damage slowly and silently; vitiated air does not, like mine gas, announce its deadly work by an explosion. As Talbot⚫ says: Health depends in part on freedom from infection. The probability of obtain- ing that freedom will be greatly increased by maintaining the body at a high state of vigor, or "vitality," as it is popularly called. This implies the promo- tion of all agencies which have to do with the physical well-being as well as with the control of sources of infection. Many men realize that in building houses for their workmen they are invested with a peculiar responsibility that must be wielded wisely, and in large developments they call into consultation the land- scape architect, the sanitary engineer, and the building architect, as well as the mining engineer.

Jan 1, 1914

By Wei Sun, Chengwei Li, Zhiyong Gao, Yuehua Hu

"Grinding for mineral liberation is a prerequisite for a successful flotation separation. Different grinding media produce mineral particles with different morphologies and surface properties. In this study, the surface physicochemical properties of fluorite particles produced by ball and rod mills were systematically investigated through single mineral flotation experiment, wettability measurement, X-ray diffraction (XRD) test and scanning electron microscopy (SEM) observations. The XRD observations reveal that the surface exposure degree for both mill particles follows the order {111} > {110} > {100}. The difference lies in that the rod mill ones have a higher exposure of more reactive {110} and {100} surfaces, leading to a stronger interaction with the collector. The difference also leads to their higher elongation and lower roundness values of rod mill particles which are beneficial for the particle-bubble attachment by shorting the induction time. The wettability and flotation results show that the rod mill ones have a lower critical surface tension and a greater hydrophobicity when treated with the collector solution and accordingly perform a higher flotation recovery. This work, for the first time, revealed the importance of the exposure of crystal surfaces in determine the shape factors and reactivity of the mineral particles and will help provide guidance for optimizing flotation separation and particle surface modification. INTRODUCTIONFluorite (CaF2) is the most important source mineral for producing F-based chemicals and materials which are widely used in industrial, environmental, and medical fields [1, 2]. In ore deposit, there are two kinds of occurrence forms of fluorite mineral. Firstly, the fluorite mainly coexisted with the gangue minerals like calcite (CaCO3) and quartz (SiO2). Because of their similar density and fine-grained dissemination in ore deposit, ball mill grinding before flotation separation has been widely applied to produce relatively fine particles [3]. Secondly, the fluorite is often associated with other valuable minerals with higher relative density such as scheelite (CaWO4) and cassiterite (SnO2). Due to their obvious density differences and coarsely grained distribution in ore deposit, rod mill grinding before gravity separation has been usually used to produce more uniform particles and avoid over-grinding [4-6]. After the gravity separation, a flotation separation is also employed to beneficiate the fluorite [7]."

Jan 1, 2018

By Kyle Kittle, Kyle Knaeble, Albert Ruiz, Gregory Raines, Ryan Gewargis

The Chimney Hollow Reservoir Project (CHRP) is located southwest of Loveland, Colorado. CHRP is a component of the Windy Gap Firming Project, operated by the Municipal Subdistrict of the Northern Colorado Water Conservancy District. The inlet/outlet tunnel (IOT) for CHRP contains a reinforced concrete lined alve Chamber with PC membrane waterproong that was ecavated via seuential ecavation method to a diameter of feet. The IOT was ecavated using both drill and blast and road header with ground support consisting of steel sets, rock bolts, wire mesh and shotcrete. The IOT will withstand 300 feet of water head and rock ll surcharge load from the dam embankment constructed over the tunnel.

Jun 23, 2024

By A. Peake

Background The CSIR Division of Mining Technology assumed responsibility for the operations of the Hoist Rope and Mechanical Test Laboratories at Cottesloe in April 1999. The laboratories were previously the responsibility of the CSIR’s Division of Manufacturing and Materials Technology, before which they fell under the National Mechanical Engineering Research Institute (also of CSIR). As the focus of this conference is on safety in mines research institutes, it was thought appropriate that this paper should review some of the activities at Cottesloe and its role in supporting mine safety strategies.

Jan 1, 2003

Objective: Improve the dust control effectiveness of enclosed operator cabs on surface mining equipment.

Oct 1, 2007

By Paulo Sérgio Moreira, Geraldo Lúcio de Faria, Rhelman Rossano Urzêdo Queiróz, Amanda Aparecida Fátima Arruda, Ana Cecília de Carvalho

O aço inoxidável ferrítico 410D (UNS S41003) é um aço relativamente novo e ainda em desenvolvimento no mercado Brasileiro. Ele tem sido posicionado como um candidato a substituir aços baixo carbono comuns e aços patináveis em algumas aplicações onde existam exigências no que diz respeito à resistência do material à oxidação e à corrosão. Entretanto, ainda existem algumas lacunas de conhecimento a respeito do seu comportamento mecânico que permitam avaliar a viabilidade de sua aplicação em condições agressivas de trabalho, como por exemplo em temperaturas relativamente elevadas. Partes estruturais de caldeiras, tubulações para condução de vapores e gases quentes, entre outros, são exemplos em potencial para aplicação do aço 410D. Nesse contexto, o presente trabalho avaliou o comportamento do referido aço quando submetido a ensaios de tração a quente nas temperaturas de 300°C e 600°, comparando-se os resultados obtidos com o seu desempenho à temperatura ambiente. Concluiu-se que o aço inoxidável 410D é susceptível ao fenômeno de envelhecimento dinâmico na temperatura de 300°C, tendo sua capacidade de deformação plástica significativamente diminuída. A 600°C observou-se uma diminuição de 45% no seu limite de escoamento e um aumento de 7% no alongamento total em relação à temperatura ambiente.

Oct 8, 2019

By Félix Lewandowsky

El presente trabajo señala el proceso de cierre desarrollado durante el año 2000 en la mina Julcani. Las etapas de cierre comprenden el procedimiento de diseño, ejecución y control-seguimiento y como tal, contienen un sistema de seguridad (SHEB) en las operaciones de la mina. El principal objetivo del proceso de cierre es la estabilización a largo plazo del entorno físico, químico y socioeconómico en las áreas afectadas por la actividad minera para asi proteger la salud, el ecosistema y reducir los efectos negativos en el ecosistema. Finalmente, es más factible ejecutar el plan de cierre durante la operación de la mina que cuando no es económicamente viable.

Sep 13, 2001

By Eric Jacobs

"Building and operating tunnels has been a highstakes endeavor in terms of costs, complexity, safety and impact on contractors, owners and the public for a long time. There are many variables that need to be closely monitored and managed to construct a tunnel on-time, on-budget and safely. Once built, there are also many elements that need to be monitored and managed to operate a tunnel safely and efficiently.Fundamentally, the risks to the safe and efficient construction and operation of a tunnel are a function of the degree of harm and the likelihood of the harm occurring. From a cyber security perspective, risk assessments used to inform decision makers and support risk responses are typically based on identification of relevant threats; internal and external vulnerabilities; the impact that may occur given the potential for threats to exploit vulnerabilities and the likelihood that harm will occur. This article focuses on creating awareness of vulnerabilities associated with technology used in tunnel construction and operation and some of the challenges associated with remediation of these vulnerabilities. As we all know, technology has been evolving at an accelerating pace and infiltrating every aspect of our lives in new and often exciting ways. In the world of tunneling, sensors and systems that provide position and time have become accurate, rugged and cost-effective enough to come out of the research labs and into the equipment and systems used every day. There are many opportunities to employ connected computing devices and sensors to costeffectively capture, integrate and analyze key data with minimal latency to manage risk better, improve safety and avoid surprises."

Jun 1, 2019

By Mark D. Hannington

Drilling of the active Trans-Atlantic Geotraverse (TAG) deposit during ODP Leg 158 indicated that the size of the mound-stockwork complex is approximately 3.9 million tonnes, including 2.7 million tonnes of massive and semi-massive sulfide (ca. 2% Cu) at the seafloor and 1.2 million tonnes of mineralized breccias (ca. 1% Cu) in a subseafloor stockwork. Quartz-pyrite veining in the stockwork zone extends from about 40 meters below seafloor (mbsf) to a depth of 95 mbsf. Siliceous wallrock breccias in the lower part of the stockwork grade abruptly into chloritized basalt breccias at the margins of the mineralized zone, and massive sulfides at the flanks of the deposit onlap relatively unaltered, partially hematized basalts. The pipe-like dimensions of the stockwork zone do not exceed the diameter of the sulfide mound. Comparisons with samples collected during earlier dive series confirm that the vent complexes at the surface of the mound are not representative of the bulk composition of the deposit. Dramatic vertical zonation of metals within the mound suggests that a long history of hydrothermal reworking has effectively stripped the constituents that are soluble at lower temperatures from the massive sulfides and concentrated them at the top of the deposit through a process of zone refining.

Jan 1, 1998