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By H. Yoshida

Jet grouting was first introduced in Japan in the second half of the 1960s, approaching 50 years ago. By the end of the first 40 years, jet grouting from single to triple fluid systems had become a global technology. In the last ten years, progress in the jetting has been remarkable, and operational efficiency has improved. The quantity of carbon dioxide emitted in unit soil improvement has become one-third that of the initial technology. Meanwhile, technologies in waste recycling and horizontal jet grouting are also emerging. This paper discusses developments in the most recent ten years.

Jan 1, 2010

By P. N. Anyalebechi

Keywords: Aluminum alloy 3004, Solidification rate, Homogenization, Second phase particles The effects of the fineness of as-solidified cast microstructure and temperature on the response of aluminum alloy 3004 to homogenization heat treatment (a.k.a. preheat) have been investigated. The study was conducted at 538oC and 595oC on directionally solidified laboratory-size ingots with a range of solidification rate of 0.10oC/s to 29.4oC/s. Optical and electron microscopy, quantitative image analysis, electrical conductivity, and electron probe microanalysis were used to quantify the effects of the homogenization heat treatment on the microstructure of aluminum alloy 3004. In general, increase in fineness of as-cast microstructure and homogenization temperature enhances the a-transformation reaction, dissolution of Mg2Si, elimination of dendritic microsegregation, and dispersoid formation. The homogenization heat treatment reduces the average size of second phase particles in castings solidified at <1oC/s. However, in castings solidified at above 1oC /s, homogenization causes the coarsening of the second phase particles. Mn in solid solution is independent of homogenization heat treatment temperature.

Jan 1, 2005

By N. Gatelier, T. You, J. C. Kandel

ABSTRACT: Underground hydrocarbons storage is a very specific domain for the designer. He is usually free to adjust the section, shape and layout to cope with the geological and geotechnical conditions. This paper presents a panorama of the geotechnical design of mined underground storage caverns, then lists a number of uncommon features encountered in a storage excavated in Sydney, Australia, the Elgas LPG project that had to face major non-isotropic conditions with numerous local variations, impacting on the achievement of the design profiles. Changes in geotechnical design methodology and practice are examined through this project, now in operation, which will have lasted altogether almost ten years. KEY WORDS: underground storage, geotechnical engineering, stability, methodology, design. ZUSAMMENFASSUNG: Die untertaegige Speicherung von Kohlenwasserstoffen unterliegt in der Planung sehr spezifischen Bedingungen. Der planende Ingenieur hat bei der Dimensionierung und Formgebung der Speicherhohlraeume gewisse Freiheiten, muss jedoch vorgefundene geologische und geotechnische Bedingungen beruecksichtigen. Der vorliegende Beitrag gibt zunaechst einen allgemeinen Ueberblick ueber die geotechnische Planung von bergmaennisch aufgefahrenen Speicherhhohlraeumen. Darueber hinaus werden Besonderheiten betrachtet, mit denen das Elgas LPG-Speicherprojekt in einer bergmaennisch aufgefahrenen Kaverne in Sydney, Australien konfrontiert war. Hierbei ging es um die Beruecksichtigung anisotroper Bedingungen mit zusaetzlichen Heterogenitaeten im Gestein und den daraus erwachsenden Schwierigkeiten, die geplante Hohlraumform zu verwirklichen. Ueber einen Zeitraum von fast 10 Jahren, in denen das jetzt in Betrieb befindliche Projekt unterschiedliche Betriebsphasen durchlaufen hat, wurden verschiedene geotechnische Entwurfsverfahren auf ihre Anwendbarkeit geprueft. SCHLUESSELWOERTER: Untergrundspeicherung, Geotechnik, Stabilitaet, Entwurfsverfahren, Planung. RESUME : Le stockage souterrain d’hydrocarbures est un domaine très spécifique pour le concepteur, car celui-ci dispose d&apos;une large liberté pour adapter les sections, les formes et les implantations aux conditions géologiques et géotechniques de l’environnement choisi. Après un panorama de la conception géotechnique des stockages souterrains d’hydrocarbures par la méthode dite des cavités minées, l’accent sera mis sur un certain nombre de particularités rencontrées lors du projet de stockage de GPL de Elgas à Sydney en Australie, creusé dans de très fortes conditions d’anisotropie du massif rocheux, avec de nombreuses variations locales et toutes les implications que cela peut avoir sur le maintien des formes. L’évolution des approches méthodologiques géotechniques durant la dizaine d&apos;années de développement de ce projet depuis les premières études jusqu&apos;à l&apos;exploitation actuelle est également présentée. MOTS-CLEFS : stockage souterrain, géotechnique, stabilité, méthode, conception.

Jan 1, 2003

By R. Mark, R. Richards

The Washington National Cathedral is one of the largest masonry structures in the USA, and like many of its European Gothic counterparts, it required nearly a century to construct. The design was altered during this period, resulting in greater loadings than were originally anticipated on the soil beneath the foundation. When signs of continuing differential settlement were observed in the early 1990&apos;s, the Cathedral approached the US Bureau of Mines (now the National Institute for Occupational Safety and Health (NIOSH)) for assistance in monitoring the movements of the massive towers and walls. An array of dual-axis tiltmeters was installed about 40m above ground level to measure wall and tower inclination, with the data sent over a dedicated phone line to the NIOSH Pittsburgh Research Laboratory for processing. Mechanical gages and string-potentiometers are also being used to measure motion across cracks and joints, and differential pier settlement is being monitored with optical-level surveying. Data have now been collected for almost 7 years, and they show a long-term settlement trend masked by dramatic diurnal and seasonal thermal movements. The paper discusses the major findings of the study, implications for the future of the Cathedral, and conclusions regarding the use of geotechnical monitoring at major national monuments.

By James R. Kerr

This study reviews the sulfur and suliuric acid industries in Eastern United States with emphasis on patterns of consumption and marketing. Output of sulfur in the East is relatively small, and most of the area&apos;s sulfur requirements are met by gulf coast Frasch sulfur. Over the long ten recovered elemental sulfur from sour natural gas and petroleum may become the East&apos;s major source of sulfur. In 1958 sulfuric acid manufacture consumed over 80 percent of the area&apos;s sulfur requirements. The leading uses for sulfuric acid were the manufacture of superphosphates and chemicals. Over the years, unit requirements for sulfur and acid in many major markets have been reduced through improved technology, but new markets always have been developed to keep the industry vital and growing.

Jan 1, 1965

Editor’s note: As usual, the June issue features an industrial minerals review. And some thanks are in order. Thank you to the industrial minerals annual-review editor, to the technical committees chair and vice chairs and to the authors of the individual commodity profiles. Jim Norman of GeoTrans Inc. is the industrial minerals annual-review editor. William Langer, U.S. Geological Survey, is the chair of the SME industrial minerals technical committees and the vice chair of the technical committee for construction materials. Other technical committee vice chairs include: •Lucy McCartan, U.S. Geological Survey, agricultural minerals. •Steve Herron, Oglebay Norton Performance Minerals, ceramics and refractory materials. •Srinivas Veeramasuneni, U.S. Gypsum, chemical raw materials. •Ismail Yildirim, Imerys, fillers and pigments. •Charles Landis, BPM Minerals, sorbents, filters and process aids. •Ray Harris, Wyoming Geological Survey, specialty minerals. Their help makes possible this June industrial minerals issue. On behalf of the readers, the editors thank them

Jan 1, 2004

By Randy Clarkson

"Free gold particles occur in many base metal and precious metal mines throughout the world. Occasionally mine operators are unaware of the presence of free gold particles in their ores because they have not seen free gold hand specimens or at the working face of the mine.Due to the high density and malleability of gold, large circulating loads of free gold particles can build up over time in grinding circuits. This gold is often deposited in unintended traps throughout the mineral processing system.These unidentified free gold deposits represent a serious security risk as well as inaccessible inventory of gold. Deposits of free gold particles often remain undetected by mine management until they are accidentally discovered while repairing mill equipment. The trapping and subsequent release of gold particles can frustrate attempts to calculate accurate metallurgical balances.Nuclear tracers have been used to determine the free gold recovery efficiency of gravity recovery equipment, drills, and sampling equipment (Clarkson, 1994, 1997, 1998, 1999 and Walsh, 1986, 1992). In 1995, the author used radiotracers to locate and eliminate gold traps at La Mine Doyon (Clarkson, 1997). In 1998 and 2001, the author also salted mineral processing circuits at Royal Oak's Pamour Mine in Timmins (Clarkson, 1999) and at Gold Corp’s Red Lake Mine in Ontario with radioactive gold particles.The gamma and X-ray radiation from gold's nuclear isotope (Au198) were detected through steel, in pipes, and in moving equipment with scintillometers. The radiotracers proved to be a safe, rapid and accurate method of identifying gold traps, improving security, determining the recovery efficiency of Knelson gold concentrators and estimating retention times of gold particles in various processes."

Jan 1, 2003

By V. B. Dale

This is one of a series of reports covering the mineral resources of the Nation. It describes briefly most of the known tungsten deposits in Yuma, Maricopa, Pinal, and Graham Counties, Ariz. Most of those described were examined by the author. An effort was made to determine the position of the various deposits by section, township, and range and to give accurate road direction to each property from a prominent landmark. All available maps have been used in making these determinations, but in unsurveyed areas it was necessary to make approximate projections of subdivisions. The township and range numbers refer to the Gila and Salt River base and meridian.

Jan 1, 1959

By James R. Kerr

This study reviews the sulfur and suliuric acid industries in Eastern United States with emphasis on patterns of consumption and marketing. Output of sulfur in the East is relatively small, and most of the area&apos;s sulfur requirements are met by gulf coast Frasch sulfur. Over the long ten recovered elemental sulfur from sour natural gas and petroleum may become the East&apos;s major source of sulfur. In 1958 sulfuric acid manufacture consumed over 80 percent of the area&apos;s sulfur requirements. The leading uses for sulfuric acid were the manufacture of superphosphates and chemicals. Over the years, unit requirements for sulfur and acid in many major markets have been reduced through improved technology, but new markets always have been developed to keep the industry vital and growing.

Jan 1, 1965

By Mark W. Booth

THE Dominion Steel and Coal Corporation, as a coal mining concern and as a steel industry, has much pumping to do, and the conditions are as varied as it is possible to make them. We are faced with handling large quantities of water at low heads, and small quantities of water at high heads. We have fresh water, we have salt water, and we have highly acidulous water (see Table II). Our pumping problems are concerned chiefly with mechanical reliability, continuous, reliable operation, first cost, and operating cost. The Corporation is actually expending more than 15 per cent of its power consumption at the mines in pumping water, and at the steel plant about 17 per cent; that is to say, 16 per cent of the Corporation&apos;s entire power consumption goes into pumping water ( see Table I). We are pumping out of the mines 2 ½ tons of water for every tan of coal that is produced. At the Steel Plant, we are pumping 188 tans of water for every ton of steel we produce. (See Tables III and IV). The mine is pumping at high heads, up to as high as 1,400 feet in one lift ; in the Steel Plant it is, fortunately, at lower heads, 250 feet or 110 lb. being the general maximum. It behooves us, therefore, to look into the question of efficiency. In whatever direction we can gain something, it will be worth while. The centrifugal pump is not an adaptable machine. That is, a pump designed for some particular location and purpose will not always work efficiently if installed in some other place and used for some other purpose. It must generally be designed for the particular job it has to do. Reciprocating pumps are not so sensitive. We have Cameron plunger pumps that can be set up almost anywhere in a mine and they will work, but for big jobs they are apt to be clumsy and the driving power becomes a factor- which is, in fact, the controlling factor in deciding the type of pump we use. One disadvantage of the a.c. induction motor, however, is that its speed cannot easily be controlled. At its rated speed and output, it is a highly efficient machine, but, with any change in these, its efficiency goes all to pieces.

Jan 1, 1944

By J. Wills

The use of drilling rigs to increasingly mechanize stope drilling has been acknowledged as important for the S.A. mining industry in it ís efforts to tackle the challenges of low productivity, AIDS and an ageing driller workforce. The spin-offs of increased safety, cost-effectiveness and better mining performance provide advantages to all?from the driller to the shareholder. However, implementation or product rollout has varied from outright success to dismal failure. A study of various cases by Novatek and Anglogold TDS showed clear reasons for these differences. Whereas the successes were characterized by clear objectives, accountability, user buy-in, a commitment to make the technology work and no-nonsense reporting, these were typically absent in failed implementations. The attitude at unsuccessful mines was to ?trial? the equipment?even subconsciously, a ?trial? is a test where failure becomes an acceptable outcome. During the study it became clear that mining management are not adequately trained to manage the often-tricky rollout process. They are often also not empowered or clearly mandated to deal with the organizational, human and technical issues that must dovetail to create a success. The output of the study was to develop a basic rollout process that could be used to formally manage the implementation of new drilling technology. Creating an alignment between the mine, workforce and supplier promotes a win-win situation that will not otherwise spontaneously arise.

Jan 1, 2002

By A. Duerksen

"Surface coal mining in West Virginia has supplied energy to the eastern coast of the United States for over a century. Over the years, the coal mining industry has been forced to adapt as societal demands regarding health, safety, and environmental impacts have changed. More recent pressure has called for another iteration of change: long-term post-mining sustainability. The research discussed in this paper investigates one potential solution - or component of a solution - to improve the sustainability of surface coal mining in West Virginia: post-mining wind power. The paper begins with an introduction to the Appalachian region of the U.S. and the role that mining has played in its history, followed by a discussion of the need for sustainable mining and how post-mining wind power may help fulfill it. Data processing methodology of field data from monitoring locations is then explained. The results are then used to estimate the electrical output of a wind turbine. This data is then utilized in a case study discussion of one of the monitored sites. The paper concludes with an analysis of the broader implications of the research and a discussion of future work."

Jan 1, 2011

By F. M. C. C. Vieira

The work described forms part of a Safety in Mines Research Advisory Committee (SIMRAC) funded project, currently an ongoing programme of research aimed at providing ?improved criteria, guidelines and the use of numerical models to design mine layouts at depth, so as to reduce seismicity and enhance worker safety?. The entire project deals with a number of distinct, albeit interrelated, research areas such as: subsidence and caving in hardrock, general numerical criteria for layout design, regional benefits of backfill, concrete pillars, strike stabilizing pillars and bracket pillars. This paper will focus on the last two items only. New considerations for the design of both stabilizing pillars and bracket pillar layouts are briefly discussed.

Jan 1, 1998

By George M. Fowler, J. P. LYDEN

T HE relationship of geological structure to orebodies and to the great masses of chert in the Tri-State mining district is of such significance that it prompts a brief recital of the existing information regarding the various periods of structural deformation. We began to note a relationship between structure and orebodies early in our studies of the field, and further work revealed a like relationship of structure to the great masses of chert so commonly associated with the ore-

Jan 1, 1934

By P Cotton, N Cox

The Brisbane City Council has implemented a program of continual improvement at its Mount Coottha Quarry in the heart of Brisbane, Australia. The program has been underway for the past 6 years, and has resulted in very significant improvements in terms of both the cost effectiveness of its operation, and in terms of its environmental impact on nearby residents. The work has included a focus, amongst other things, on blasting efficiency and has challenged conventional thinking in terms of the size of blasts fired, the frequency of firing, the diameter of blastholes, and the use of bulk emulsion or slurry explosives.

Jan 1, 1996

By Richard E. Gray

The Office of Surface Mining Reclamation and Enforcement (OSM) is preparing an Abandoned Mined Lands Reclamation Control Technology Hand- book. (l) GAI Consultants, Inc. , recently prepared Chapter 2 on Mine Subsidence Control which contains a summary of subsidence abatement measures plus two new decision matrices for evaluating the subsidence abatement options that might be considered for a particular problem. These decision matrices are presented for information. Review of the subsidence abatement methods resulted in identification of items where research may impact the current state of technology in mine subsidence control. These research needs are presented to stimulate discussion of their importance in subsidence abatement and to encourage funding agencies, researchers, and practitioners to work on them.

Jan 1, 1982

By L. Douglas Smoot

This research program was a theoretical and experimental study to improve understanding of the mechanisms of flame extinguishment in methane-coal dust-air-suppressant mixtures. This final report is a summary of work conducted during this grant, sponsored by the Bureau of Mines. Work under this new grant closely followed a recently completed contract for the Bureau of Mines that was conducted at this laboratory, and results of the earlier contract are also summarized in this report, as required in the grant work statement. The experimental effort was concentrated on supplementing the limited data available to describe laminar flames in methane-coal-air-suppressant mixtures. The theoretical effort was devoted to developing a comprehensive model that could be used to explain and extrapolate the experimental data. Selected for study were the following flames: Methane-air; methane-air plus KHCO , KNO3, K C204, KBr, Al203 or Monnex; methane-coal dust-air; coal dust-air with size, volatiles content, and concentration as variables, and coal dust-air plus KHCO3, KN03, KBr, NaCl or CaC03.

Jan 1, 1978

By T. J. Batchler

Deformable materials are sometimes added to ventilation stopping constructions to prevent damage caused by convergence in coal mines. However, adding deformable materials can significantly reduce the capacity of a stopping to resist transverse loading. As part of its mining health and safety program, the National Institute for Occupational Safety and Health (NIOSH) has conducted research on the effect of various materials with different deformation properties on the transverse loading capability of a stopping wall. Based on a three-point hinge method of failure, a half-wall method of testing in the NIOSH Mine Roof Simulator was used to simulate full-scale wall behavior. This simulated the fracture initiation and eventual failure of the stoppings from transverse loading. The impact of the modulus of elasticity of various deformable materials was examined in this study. A polystyrene foam block with a low modulus of elasticity, which is commonly used as a deformable material, was shown to degrade the transverse load capacity of the stopping by as much 95%. Other materials with higher modulus of elasticity preserved more of the transverse load capacity of the stopping, but were not able to absorb as much convergence. This paper presents the results of a parametric study that quantifies the impact of various deformable materials in block stopping construction under transverse load conditions. Disclaimer: The findings and conclusions in this report have not been formally disseminated by the National Institute for Occupational Safety and Health and should not be construed to represent any agency determination or policy.

Jan 1, 2009

This Bureau of Mines publication contains five papers pertaining to the effective grounding of mine power systems, as follows: Ground-check monitor types and safety characteristics; ground wire monitors for surface coal mines; ground bed design and measurement; electrical ground rod corrosion; and a continuous ground bed resistance monitor.

Jan 1, 1979

Workers in underground stone mines have a high fatality rate caused by falls of ground from the mine roof or rib. NIOSH recommendations to reduce ground fall injuries and deaths address baskets, mechanical scalers, mechanical bolters, drill steel changing, personal protective equipment, and training. Description of Exposure An informal National Institute for Occupational Safety and Health (NIOSH) review in 1998 identified approximately 17 new underground limestone operations in vari¬ous stages of planning; as many as 35 new underground stone mines are expected by 2005. Many of these new underground stone mines will employ new or inexperienced workers with minimal knowledge of the hazardous conditions that exist underground. Workers in underground stone mines have a fatality rate nearly 20 times that of workers in the manufacturing sector. Three quarters of the fatalities in underground stone mines are caused by falls of ground from the mine roof or rib (Figure 1) [Statistical Abstract of the United States 1985-1999; MSHA 1983-1999]. During 1983-1999, nonfatal ground falls resulted in 140 injuries, or 15% of all underground, lost time stone mine injuries. These nonfatal ground fall injuries resulted in more than 13,800 lost workdays (one third of all lost workdays). Ground falls generate more disabling injuries and time away from work than any other type of incident. [ ]

Jan 11, 2003