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By Verne E. Hooker

Stress-relief techniques and instrumentation have been developed through many years of research in the Federal Bureau of Mines and successfully used to determine the in situ state of stress in rock. This paper describes the drilling equipment and accessories for use with the Federal Bureau of Mines three-component deformation borehole gage. Operation and calibration procedures for the deformation gage are discussed in detail. Site selection and overcoring procedures are included to provide a complete working knowledge for surface or underground applications.

Jan 1, 1974

By Louis J. Sousa

In November 1989, the U.S. Bureau of Mines sponsored a 2-day conference to stimulate thinking and discussion about changing materials technologies and implications for the Government's materials information programs. On the first day of the conference, speakers provided overviews of developments occurring in each of the major materials groups. Emerging technological developments, applications, economic and national defense significance, intermaterial competition, and potential market growth in advanced plastics, polymer composites, ceramics, metals, and electronic materials were described. In general, the speakers forecast advanced materials market growth rates in excess of overall gross national product (GNP) though high costs will tend to limit growth outside of aerospace, defense, electronics, medical equipment, and other typically high value-added businesses. On the second day, a wide range of speakers representing several facets of the materials community described how advances in materials technology are creating a need for new types of data, statistics, information, and analysis. Reflecting the speakers' broad range of organizational, professional, and personal perspectives, an array of information needs was identified. Most requirements, however, seemed to fall into one of five major categories: Federal materials research activities, material standards, market and economic information, health and safety, and public policy.

Jan 1, 1990

By John K. Alley

Despite the extensive use of fluorphlogopite, investigators do not agree as to its exact melting temperature. Data on other fluormicas and on related fluorsilicate systems are largely nonexistent. A knowledge of the melting temperature is necessary for the effective synthesis and use of fluorphlogo¬pite or other fluormicas. The increasing use of two- and three-mica systems to yield polycrystalline ceramics has made more urgent the need for melting temperature information concerning these other fluormicas. This report is part of a program by the Bureau of Mines to synthesize large-size or large-crystal fluorphlogopite and develop a usable reconstituted fluormica sheet. The melting temperature of fluorphlogopite, K2Mg6A12Si6020F4, was found to be 1,383° ±2° C. This temperature was found by studying single crystals of fluorphlogopite, heating behavior of glass of fluorphlogopite composition, and the actual crystallization of fluorphlogopite from a melt that had been heated above 1,430° C. The formation of forsterite or norbergite was directly proportional to the loss of volatiles during the experimentation. Many trials revealed that the only reliable seal was a thick platinum sheet with welded seams. If no volatiles were lost, neither norbergite nor forsterite were formed; fluormica was then the only product. Excellently formed crystals of forsterite with an optical sign different from ordinary forsterite were obtained during the single crystal melting experiments. These crystals resulted from a slow loss of volatiles. A congruent melting of fluorphlogopite is indicated by the data of this report; however, incongruency within a small temperature range is not precluded. A more refined method using phase equilibria-quench methods would be necessary to settle the question absolutely.

Jan 1, 1962

By A. Danaei, A. McLean, M. Barati, C. Ravindran

"The aluminum industry generates about 90 million tonnes of red mud each year. Previous research shows it could be utilized as a refining flux with a high capacity to absorb phosphorus and sulphur from hot metal in the steel industry. The present study was undertaken to evaluate the melting properties of such fluxes, as it affects the effectiveness of the flux. The results show that the melting behavior of red mud is strongly affected by lime addition and the characteristic melting/softening temperatures reach minimum VALUES (at 32.7 wt% CaO. From these findings, a correlation was established between melting behavior and optical basicity. This allows one to adjust the composition of the flux based on the process requirements. INTRODUCTIONThe aluminum industry generates about 90 million tonnes of bauxite residues each year. This residue is usually red in color because it contains a substantial amount of iron oxide. The red mud, as it is called, is a solid waste with a high concentration of sodium oxide, high pH (10 to 13), and high alkalinity, and thus is harmful to many forms of life. Traditionally, the material is stored in large tailings ponds within the plant’s vicinity (Power, Grafe, & Klauber, 2009). Development of solutions for safe disposal or preferably using this residue for other industrial processes or applications could help restore polluted locations and eliminate a negative impact on the environment (Haake, 1988; Power et al., 2009; Yan & Xuegong, 2010).The mineralogy and chemical composition of red mud depends on the quality of the bauxite and refining process parameters. In general, it consists of iron oxide (Fe2O3), aluminum oxide (Al2O3), titanium oxide (TiO2), sodium oxide (Na2O), silicon oxide (SiO2), and calcium oxide (CaO) (Power et al., 2009). Like most ores and soils, bauxite can contain trace quantities of metals such as arsenic, beryllium, cadmium, chromium, lead, manganese, mercury, nickel, and naturally-occurring radioactive materials, such as thorium and uranium. Most of these trace elements stay in the residue (Power et al., 2009)."

Jan 1, 2012

By H G. Bosmare, G Bedser, C V. B Cunningham

Peak Quany has achieved substantial improvements to its bottom lie by giving close attention to blasting practice, and in pr@icnlar by introducing electronic delay detonators for routine production blasting. The precision and flexibility provided by these units has enabled the quarry to gain control over fmes and curtail oversize without increasing explosive usage. In addition, the extent of nuisance from blasting vibrations has been reduced.

Jan 1, 1998

By L. J. Gardner

Ore pass systems play a critical role in moving broken rock from the workplace to surface, and the integrity of the ore pass excavations is crucial. Over the life of the mine, ore pass integrity deteriorates, which may eventually result in the ore pass no longer being fit for purpose. This paper presents several case studies of successful ore pass rehabilitation exercises.

Jan 1, 2006

By G. Thodos, D. E. Matschke

Cansiderable time and effort frequently are expended to establish, with a degree of confidence, the PVT behavior of pure substances. In particular, a great deal of experimental information contributed by a number of investigators is available in the literature. The data of each investigator, although significant in themselves, cannot be used with a high degree of confidence until they are compared with the continuum of information presented by others. Current interest in thermodynamic and transport properties, for not only the gaseous state but the con-densed state as well, requires that PVT infarmation be presented for both regions. The density dependence on temperature and pressure, when presented as a continuum, is of considerable value in itself, especially since the available equations of state fail to properly account for the PVT behavior in the condensed state. For this reason and to incorporate PVT data recently presented in the literature, this investigation was carried out. In their studies concerned with the thermodynamic properties of methane, Matthews and Hurd in 1946 utilized the data of Kvalnes and Gaddy and Olds, Reamer, Sage and Lacey to establish the PVT behavim of methane in the superheated region and the saturated liquid densities of Keyes, Taylor and Smithl in conjunction with the Clapeyron equation to develop the densities for the saturated envelope. Current activity sponsored by API Project No. 44 under the direction of F. D. Rossini has led to a tabular presentation of compressibility factors for gaseous methane in the superheated region.la These values were obtained by using smoothed residuals, developed from experimental data and the Ben edict-Webb-Rubin equation,' to establish internally consistent compressibility factors for the real gas. This approach offers probably the most precise presentation of PVT information for gaseous methane to date. The PVT behavior of methane also can be represented accurately by equations of state such as the Benedict-Webb-Rubin equation or the Martin-Hoa equation.' These equations, although valuable for analytically representing the PVT behavior, lack precision in the compressed-liquid region. The PVT data available in the literature for methane were utilized to obtain reduced densities that are presented in Figs. 1 and 2 as functions of reduced temperature with parameters of reduced pressure. The critical constants utilized for methane are those reported by Kobe and Lynn." These critical values, T, = 191.1°K, PC = 45.8 atm and p, = 0.162 gm/cc, produce a critical compressibility factor, z, = 0.289. The PVT information, as obtained from the literature, in many instances was not presented in an immediately

By John R. Hoskins

The Bureau of Mines conducted an investigation to more exactly define the influence of some end conditions on the laboratory-determined uniaxial compressive strength of rock samples. Limestone, marble, sandstone, and granite were used to provide a range of specimen modulus of elasticity from 2.7 X 106 psi to 10 x 106 psi. Four variables were studied: Nonparallelism and surface texture of specimen ends were the specimen variables investigated; the end platen size and the adjustable or spherical head friction were the machine variables studied. It was concluded that the loading ends of small laboratory models and samples should be prepared with surface irregularities that do not vary from a plane surface by more than 0.001 inch. It was also concluded that nonparallelism of the specimen ends should not exceed 8 minutes for a rigid head load or 15 minutes for an adjusting head load. The measured compressive strength of specimens prepared with these tolerances will be statistically the same with any diameter or thickness of platen and any degree of head friction if initial alinement of the specimen is assured.

Jan 1, 1968

By Louis M. Schlesinger, Joel F. Hutwelker

A pilot plant was constructed to attrition scrub and deslime North Carolina phosphate ore. A 15.2 cm (6 in.) diameter pilot-scale Linatex Hydrosizer was used for desliming. Four tests were run at a throughput of 2.9 t/hr/m2 (0.30 ton/hr/f t2) and a teeter bed density of 1.12-1.13 g/cm3. The teeter water flow rate was varied to create an upflow velocity ranging from 0.25-0.47 cm/s. (This latter value is equal to the terminal settling velocity of a 200 mesh (74 micron) particle having a density of 2.7 g/cm3.) The recovery of +200 mesh oversize to the sizer underflow was 95%-96%, regardless of the teeter flow rate. The recovery of -200 mesh undersize to the sizer overflow increased from about 90% at 0.25 cm/sec to 100% at 0.47 cm/sec. A metallurgical balance that was conducted for one of the tests showed that less than 2% of the phosphatic value was lost to the overflow. A fifth test was run using an upflow velocity of 0.47 cm/sec; however, the teeter bed density was maintained at 1.05 cm/sec. This change had the effect of reducing the cut point (d50), while maintaining complete slime removal.

Jan 1, 1993

By Trevor Hamm, Nick Holl

"Cameco Corporation is operator of the world's richest uranium project, the Key Lake mine/mill complex, located within the Athabasca region of Northern Saskatchewan. Mineable resources from the Key Lake ore bodies with an average U,08 content of 2.5% will be exhausted by the year 2000 and open pit mining at Key Lake will be phased out at that time. The mill will continue to operate at increased capacity, using high grade ore from the McArthur River project, a new underground mine at a distance of about 80 km from the Key Lake site. The McArthur River ore with an average U308 content of about 15 % will be blended with separately stockpiled low grade materials from Key Lake with a U,08 content of about 0.1 %. The average (blended) mill feed grade will be about 4%, similar to peak concentrations found in Key Lake ore.The Key Lake ore tailings are presently being placed in the mined out Deilmann pit under sub-aerial conditions, using spigots and a highly efficient pit/tailings drainage system. The tailings resulting from the processing of the blended McArthur River ore will be deposited on top of the Key Lake ore tailings under sub-aqueous conditions. This staged approach shows distinct technical and environmental advantages over an alternative, fully sub-aerial in-pit deposition scheme.The first part of this paper presents an overview of site specific geotechnical and hydrogeological features found at Key Lake and details some of the extensive test and modelling work that was required for environmental impact predictions during the development phase of the facility. The second part of this paper deals with tailings modifications, innovative placement technologies and drainage methods that have been (and will be) employed at the Deilmann Tailings Management Facility {TMF) to produce a highly consolidated tailings body under non-buoyancy conditions. The application of this technology at Key Lake is expected to produce a tailings ""plug"" in the Deilmann TMF which will have a permeability similar to or lower than the original in-situ Deilmann ore, resulting in a minimization of contaminant mass loadings to the environment both during operation and after decommissioning."

Jan 1, 1998

By Ruilin Yang

"Blast vibrations are essentially a strain/stress wave propagating in rock or structures inthe vicinity of a blast. However, blast vibration has always been quantified in terms ofpeak particle velocity (PPV) or acceleration (PPA), and a meaningful relationshipbetween blast vibration and strain/stress has not been established. The determination ofthe dynamic strain from blast vibration may improve quantification of blast damage andselection of a blast vibration limit for critical structures or high walls. Dynamic strainrelates to rock mechanics or material strength more directly than peak particle velocity(PPV). This paper documents a method to calculate the three-dimensional dynamic straintensor from recorded blast vibration signals. The method is based on determination of thedisplacement gradient at a point of interest for each time instance during the vibrationduration. The method to calculate dynamic strain is applicable to generic seismicwaveforms including near and far field blast vibration from a production blast withmultiple blast holes. In order to minimize measurement errors the specifications of thespacing between monitors and the sampling frequency of the vibration recording aredescribed."

Jan 1, 2012

By N. Seidle

Numerous studies conducted in the 1960's and 1970's concluded or implied (1) that a high accident rate in terms of severity and frequency exists among new (first year) operators of mine machinery equipment, and (2) that lack of experience and training is a major cause of this high accident rate. Further studies refined this premise to show that the major causes of accidents among first year operators are: (1) lack of manipulative skills; (2) failure to follow/adhere to routine procedures; and (3) failure to recognize and respond properly to hazards. This report describes the design, development, and manufacture of a shuttle car operator training system, including a program of instruction which: ? Is economically feasible. ? Addresses accident data and specific causes of accidents. ? Includes an aerospace quality simulator of sufficient fidelity to teach and develop manipulative skills, recognition of and response to hazards, and routine and emergency procedures. ? Is designed to significantly reduce the severity and frequency of accidents especially during the operator's first year. ? Is designed to significantly improve the performance of the trainee as compared to the standard learning curve. Development of the simulator produced several valuable by-products including a major state-of-the-art technological advance in visual systems for simulators, and a first-time application of (certain) advanced filming techniques to underground filming.

Jan 1, 1984

By P. A. Neill, O&apos

The caisson foundation for Vent Building No. 6, at the southern landfall of Boston's Third Harbor Tunnel, was installed inside an unbraced concrete cofferdam 250 feet in diameter and about 70 feet deep. As a spectacular engineering feat, the cofferdam itself certainly ranks first. However, the foundation work within was no routine caisson job and made its own contribution to the state of the art. Comprised of 5 ft. diameter caissons socketed 10 to 16 feet in sound rock, it posed serious challenges in logistics, space limitations and time, requiring development of unique, purpose-made equipment. The unexpected discovery of significant depths of shattered rock overlying acceptable sound rock, along with other surprises of lesser import, compounded the problems. How these challenges were planned for, met and overcome is the subject of this paper.

Jan 1, 1994

By Jon Kellar, Samuel Kessinger, Prasoon Diwakar

Tantalum (Ta) and niobium (Nb) are extracted from many different ore types. The major economic orebody mined for tantalum and niobium consists of tantalite ((FeMn)Ta2O5) and columbite ((FeMnNb2O5)) in a solid-solution mineral commonly referred to as “coltan.” The largest supplying region, The Democratic Republic of the Congo (DRC), is unfortunately also the most ethically compromised source for this critical mineral. Officially, the U.S. government has deemed coltan ore from the DRC a “conflict mineral” [1]. The lack of pragmatic and effective local mining regulation in Central Africa, when coupled with high levels of violence and corruption, has spawned a widespread, illegal, unethical and, most importantly, unsafe economy. This illicit economy is centered around first, illegally mining these valuable conflict minerals and second, smuggling these minerals into the global supply chain. Handheld spectroscopy devices could provide further transparency to these opaque supply chains, giving miners, traders and refiners the ability to authenticate the provenance of the minerals they encounter, and allowing companies to prove compliance with the regulatory agencies attempting to curtail illicit mining.

Mar 1, 2025

The works recorded in this Test Report have been performed by Rade Roncar - Electrotechnical Institute of Zagreb, SFR Yugoslavia in collaboration with Bureau of Mines. The main objective of these investigations was to investigate the possibility of fabrication of thin-walled square enclosures of satisfactory safety factor in accordance with requirements of effective technical regulations. The results and the investigations can be divided in three main fields: - investigations of thin-walled enclosures with the view of determination of pressures causing technological deformations before performing tests in accordance with effective applicable regulations, - finding the safety factor by means of tests of metal-foam pressure vents, - comparison of enclosures with and without pretreatment by technological deformation.

Jan 1, 1987

By James A. Schneider

Selection of resistance factors within Load and Resistance Factor Design (LRFD) requires accurate assessment of uncertainty and bias in load and resistance. To date, many studies have focused predominantly on the assessment of uncertainty, while the potential for bias appears to be the dominant factor in design for consistent levels of reliability under a variety of situations. Bias comes from factors which have been ignored in design method development but significantly influence resistance when extrapolating from conditions typical of databases to those at a given site. Uncertainty and bias can be quantified as the coefficient of variation and mean (or median) of a data set, respectively, for statistical assessment of load and resistance factors. This paper first presents an overview of statistical assessment of resistance factors, and then discusses factors that influence uncertainty and bias when extrapolating to situations outside of conventional databases of driven pile axial capacity.

Jan 1, 2009

The purpose of this report is to describe the work accomplished by Mine Safety Appliances Company under Contract No. H0110845. This contract required the design, installation and testing of a permissible mine surveillance and communication system for the USBM Bruceton experimental mine facility. While much of the design and operational detail of this system can be drawn from the instruction manuals delivered with the equipment, some of it will be repeated here in Volume I for the sake of clarity, but the principal objective will be to report on overall system and subsystem performance and to suggest design alternatives for future consideration. Details of the overall system design will be found in Volume II of this report.

Jan 1, 1973

By Boorder De, B. S. Panov, A. B. Westerhof, V. A. Korcemagin

Paper presented at the conference on Economic geology in Europe and beyond II, models for <mineral deposits> in sedimentary <basins>, held in Keyworth, UK, 13-14 April 1994. The Hg and Sb deposits of the Mediterranean and Circum-Pacific Belts are often found at elevated structural levels, suggesting that their preferential occurrence in young orogenic belts is not a fundamental metallogenic feature but merely reflects their chances of surviving post-orogenic peneplanation. In western Europe their emplacement appears often to be related to late orogenic extensional events accompanied by a notable increase in heat flow. Although Nikitovka and Almaden have quite different settings, both appear to be related to deep-reaching shears. Together with brittle fault zones at higher levels, these provided pathways for fluid phases that originated at least partially within the mantle. The Nikitovka deposits are located in the Donets segment of the 2 000 km Pripyat-Dniepr-Donets palaeorift in the East European Platform. Initiated in the mid-Devonian with a possible Precambrian precursor, its listric boundary faults displace the Moho from a depth of about 50 km north and south of the rift to 35 km along the axes of the Pripyat and Dniepr segments. The steep central anticline of the Donets segment, within which the main Hg-Sb district is located, is interpreted to be associated with a reactivated fault reaching into the upper mantle. The Almaden syncline, formed during the Variscan Orogeny, may be an older pull-apart basin or half-graben associated with the collapse of the Cadomian Orogenic Belt. It is situated on a major ENE-WSW-striking shear zone which may represent a Late Cadomian transfer zone reaching into the mantle

Apr 1, 1995

By S. K. Mathur

This report identifies all the possible activities, variables and factors that contribute to the surface subsidence process over room and pillar workings. These factors are responsible for mine instability and collapse that ultimately transforms into surface subsidence. Such a failure mechanism is initiated by the failure of the mine floor bed and or the failure of the pillars or the failure of the roof after second mining, which eventually brings down the roof. The individual responses of the pillar, floor and roof rocks to the mining induced stresses and the complex interaction between these components can&apos;t be attributable to any single factor. Also, no attempt has been made to quantify the significance of each of these factors and relate to the ground subsidence due to the lack of field data. The discussion here is centered primarily on the first mining though second mining is mentioned very briefly,

Jan 1, 1982

By K. K. Kershner

The purpose of this investigation was to develop methods, on a laboratory scale, for recovering tin from Bolivian metallurgical slimes. Petrographic and chemical analyses were made of slime ore fractions from several well-known tin operations. High percentages of the total tin were volatilized as chlorides at temperatures below 600° C. Under optimum conditions reaction rates were relatively rapid, and the chloridizing reaction approached completion. Owing to the low temperatures involved and the high yields of tin, the process was considered to have possibilities for treating Bolivian slimes on a commercial basis. ACKNOWLEDGMENTS Appreciation is hereby extended to the Patino Mines and Enterprises, Inc., of Bolivia, for supplying slimed tin ores that were used in the experimental work. This company has since been nationalized.

Jan 1, 1959