Search Documents

By Peter Duniam, Stephen John Brace

2000 HIGH-TECH SEMINAR Blasting Technology, Instrumentation and Explosives Applications Orlando,Florida,USA July24-27,200O. Objectives:- After completing this session 1. Explain safety issues 2. Do simple initiation design 3. Describe how the system works 4. Demonstrate scanning, hookup, testing and firing 5. Describe hot to do a post blast check 6. Explain how to treat misfired detonators

Jan 1, 2000

By A. R. Dover

The Richmond-San Rafael Bridge is a 6.92 kilometer (4.3 mile) long major toll bridge span that crosses the northern San Francisco Bay in a highly seismically active region. Tutor-Saliba / Koch / Tidewater JV was contracted by Caltrans to conduct a comprehensive seismic retrofit. The JV provided geotechnical planning and quality control services as described herein, under normal oversight by Caltrans. Part of the robust foundation retrofit design included the installation of 26 new, large diameter piles, including eleven 3.81 m (12.5 ft) diameter, cast-in-drilled-hole (CIDH) marine piles that were drilled 9.15 m (30 ft) into the bedrock beneath the Bay, where the water depth ranged up to about 21.3 m (70 ft). These reinforced concrete-filled composite piles have a steel shell permanent casing from the bridge substructure pile cap through the water column and 30.5 to 39.6 meters (100 ft to 130 ft) of marine sediments to the top of rock. This paper discusses construction, inspection (ranging from the QA employed in the planning of the CIDH pile installation methods and equipment to the actual construction inspection required for the routine installation of the shafts), problems that were encountered during construction, and the solutions that were developed and implemented. Inspection, particularly with the usual difficulties in the marine environment, coupled with the difficult and complex bedrock conditions was particularly challenging, and ranged from non-destructive testing to "in-water, inshell" diver inspection. Similarly, the complexities of dealing with both the steel casing "riser" and the associated drilled shaft (rock socket) portion of these composite foundation elements created some unusual issues. The paper also presents important lessons learned from the project.

Jan 1, 2008

The Heavy Media Separation plant operated at Lidsdale siding, eight miles from Lithgow, by the N.S.W. Mining Co. is a product of the Western Machinery Company, of D.S.A.This mill, designed to use finely ground magnetite as the heavy medium, was prefabricated in America and shipped to Australia for erection.First operated early in December, 1951 it has worked on a two-shift basis since. Designed for an input rate of 330 tons per hour, this mill is capable of washing 4 in. x /u in. coal down to its inherent ash by removing all heavy material, including high-ash coal.The principle is quite simple. A stream of raw coal is fed into the separatory vessel which contains a liquid medium, the density of which is adjusted to produce the desired split between coal and refuse. In this bath the lightest coal floats, and all material heavier than the specific gravity of the medium sinks, and is removed separately. Such a system is,. ideally suited to Western coal, as there is no definite splitting point between coal and refuse. Inherent ash of the coal fed to the plant ranges from 8 to 25%, the corresponding density range being from 1.28 up to 1.8.Generally speaking, the higher the density the higher the ash content of the coal.The density in the separatory vessel (hereafter called the cone) can be quickly and easily adjusted throughout the above range to any desired value. Customer requirements, coupled with the economics of washing, dictate the proper specific gravity to be maintained. At present this is held at 1.52...

Jan 1, 1954

By Jay Rodgers

There has been a longstanding acceptance that burden plays a major role in the magnitude of ground vibration amplitudes generated from surface blasting. Much of the data that this belief is based upon is empirical in nature and may or may not represent an example of false inference. Recent published reports have rightly questioned the influence of burden and confinement on blast vibration amplitude, suggesting that the fracture condition of the rock mass is a better indicator. The increased investment in electronic detonators as a tool to control ground vibration amplitudes demands an understanding of vibration production detailed enough to make use of the vastly improved timing accuracy that they provide. A more accurate relationship may be found if we strip away the assumptions of the past and search for the underlying mechanism of vibration production in surface blasting. We must answer the question: What happens at or near the borehole when an explosive charge detonates that produces ground vibrations?

Jan 1, 2003

By John J. Vieaux

Allowable loads on Dynamically-Cast-In-Place Piles (the Franki type) can be correlated with N values from the Standard Penetration Test. Using a constant developed by Nordlund, a conservative value for load-carrying capability of a DCIP pile is developed. The DCIP pile and method of installation is briefly described.

Jan 1, 1984

By I. W. van der Merwe

Recently, a new kind of filtration has emerged, namely nano-filtration (NF). It is a membrane-based process which exhibits totally unique separation characteristics for dissolved salts as well as for many non-charged species. By exploiting the particular separation characteristics of this new membrane type, many unique and novel separations have been made possible. The basis for separation by nanofiltration is the negative surface charge of the membrane. This results in rejection of multivalent anions, whilst associated cations are also rejected to maintain electro-neutrality. This peculiar property enables separation of dissolved ions such as sulphate and copper from acid, whilst the acid may be purified for reuse. This paper aims at providing an overview of the principles of nanofiltration, illustrated by particular examples.

Jan 1, 1998

By Luis Martín Tejada

Para la evaluación de la estabilidad de taludes en minería superficial se utilizan diferentes métodos de modelamiento y planeamiento como el de simulación numérica. En ese sentido, el presente texto describe el método de tensión-deformación, cuyo base se encuentra en el método numérico de elementos finitos, y así localizar la probable superficie de ruptura. También se describe los mecanismos de ruptura en taludes altos, el cálculo del FS y algunas características del programa de elementos finitos PLAXIS.

Sep 9, 2007

By H. Lyn Bourne

This is the fourth annual tabulation that gives mineral royalty information. The table presents previous information plus about two dozen new entries. In addition to the royalty information, some entries show the cost of purchased reserves. Last year's tabulation appeared in two issues, to accommodate all of the information. This year the format has been changed slightly so the table can be printed in one issue. This year's table presents the commodities in the same sequence as last year. Sand and gravel information appears first, followed by: crushed stone for aggregate; other stone; industrial sand; other industrial minerals; energy minerals (coal, oil shale, uranium); and finally metals. As always, a caveat relates to factors that influence the reserve values. The data should serve only as a general reference. The table is not intended to present an absolute scale of reserve costs. Several factors influence the value of mineral commodities. These factors include: • location and transportation costs (especially significant for most industrial minerals); • market conditions for both the commodity and the company acquiring the right to mine it; • quality or grade of the deposit as it reflects the amount of processing and beneficiation necessary to produce the finished product; • and legislative restrictions and conditions for mining a given material at a given site. These and other factors will influence reserve costs of reserves. The table shows the range of royalties and the variations in the basis of computing the fees. In a few instances, it gives the cost of acquired reserves based on purchase price and quantitative estimates of the material in place. The table lists the commodity; the location (either by state, US geographic area, or Canadian province); the cost (R for royalty and P for purchased cost); and the year in which the lease or purchase agreement occurred. The last column offers either comments or gives a footnote number for more information. The cost column requires more explanation. The units may refer to cubic yards (/yd), cubic feet (/cuft), tons (/T) (2000 lbs) or acres (/A). 1 cu yd = 0.76m3 1 cu ft =0.28m3 1st = 0.9 t7 1 acre = 0.40 ha or m2 In several cases the royalty is a percentage of the finished products, sale price and is levied against either the amount produced or the amount sold. We thank those who contributed information for the table: J. Dunn, T. Eyde, K. Loda, L. Morgan, F. Nix, H. Sorenson, and L. Williams. Several people have said they would like this to be an annual tabulation. That can happen if new information comes to the writer. What appears in the table is only a very small fraction of the cost information relative to the various commodities and the geographic areas for which there is royalty information. If you find this column of interest and possess information write or call: H. L. Bourne, c/o Neyer, Tiseo & Hindo, Ltd., 38955 Hills Tech Dr., Farmington Hills, MI 48018, (313) 553-6300. Only with new information can this become an annual and current source of reserves costs.

Jan 8, 1986

By R. D. Williams

In spite of the increasingly polarized and politicized view of climate science and climate change in the United States, many of the principles behind the ?theory? of Anthropogenic Global Warming (AGW) or Global Climate Change (GCC) are in fact firmly established both in fundamental physics and detailed observations and are widely accepted elsewhere. The discovery of the earth?s ?greenhouse effect? dates back nearly 200 years to the work of French mathematician and physicist Joseph Fourier in 1824 and 1827. In 1872, John Tyndall an English physicist and mountaineer, described the capacity of various gasses to absorb radiant heat. He identified water vapor and carbon dioxide as the principal ?greenhouse? gasses. The work of Fourier and Tyndall was the foundation for the theory that increasing carbon dioxide (CO2) in the atmosphere might be responsible for an increase in global temperatures developed by the brilliant Swedish chemist Svante August Arrhenius in 1896. This was backed up by the additional work of Gilbert Callendar in the 1930s, and Gilbert Plass, Hans Suess and Roger Revelle in the 1950s. There is little scientific dispute about the physics by which this occurs: carbon dioxide in the atmosphere absorbs long wave radiation that would otherwise escape into space, thus warming the lower atmosphere and respective temperatures worldwide. The Intergovernmental Panel on Climate Change (IPCC), approximately 2500 climate scientists from around the world, has concluded that increases in carbon dioxide resulting principally from the burning of fossil fuels are responsible for most of the continuing increases in global temperatures (IPCC, 2007). NASA?s Goddard Institute for Space Studies (GISS) states; ?The ten warmest years all occur within the 12-year period 1997-2008? (GISS, 2009). 2009 was the second warmest year on record and 2010 was tied with 2005 for the warmest year on record (GISS, 2010, 2011). The science is in fact settled; the earth has not cooled since 1998 as some have claimed. It continues to warm as evidenced by not only surface temperature records but also ocean temperature records as well as changes in physical and biological systems (IPCC, 2007).

Feb 27, 2013

By Fred W. Brackebusch

"The use of paste technology for surface tailings disposal may offer economic, technical, safety, and environmental advantages for both underground and surface mining operations. Paste is a non-Newtonian fluid having some shear strength during transport and placement. The strength is augmented after placement by consolidation, water loss, and by addition of chemicals. Economical dewatering systems are necessary to the success of surface paste tailings disposal. In an underground mine, the paste backfill plant can produce paste for surface disposal about 50% of the time because only about 1/2 of the tailings are needed for backfill. The distribution of paste to the surface stack involves expensive pumping equipment and thus a nearby location of the stack is desirable. The viscosity of paste can often be manipulated by modifying pH. Placement of the paste in a designed stack configuration depends on topographic and climatic factors as well as paste properties.INTRODUCTIONThe use of paste technology for mine backfill is becoming accepted for underground mines mainly because of ground control and economic reasons. Paste technology is just starting to be applied for tailings disposal with only a few hardrock metal mines worldwide using the technology; however, it has been used extensively for red mud disposal in the aluminum industry. The disposal of dry tailings is very attractive from environmental and safety points of view because of limited water which might potentially escape and pollute river systems. Dry stacking systems, however, are expensive because of filtration and truck transportation costs. Paste can be produced from most tailings streams by special types of thickeners. Furthermore, it can be transported in pipelines, therefore paste technology may be more economic than dry stacking but still have some of the major advantages. Understanding of paste technology has improved through experience with operating underground backfill systems in recent years and because of testwork and research programs by mining companies, consultants and equipment vendors. Thus we may be on the verge of taking a new look at tailings management using paste technology."

Jan 1, 2002

By Jeffrey M. Listak

This report describes a study, conducted jointly by BethEnergy Mines Inc. and the Bureau of Mines, to assess the effects of longwall front abutment loading on various supplemental support materials utilized in a predriven recovery room. The purpose of the predriven recovery room is to reduce longwall equipment transfer time by eliminating the premove preparation associated with conventional recovery methods. In addition, the room provides a large area in which face salvage equipment can maneuver. Results of four recovery-room study areas show the progression and influence of the front abutment on the longwall panel and supports and their subsequent behavior. The best performance (i. e. the support that most facilitated recovery) of support material was achieved through the use of a concrete mixture which had a sand content of 35 percent by volume. The longwall transfer time was reduced by 30 percent which translates to a production advantage of 37,000 raw tons of coal per panel.

Jan 1, 1989

By Daniel Su

Approximately 90% of the primary roof bolts used in CONSOL?s Pittsburgh seam coal mines is 2-piece, 8-foot long, 7/8? (or ¾?), high-strength, resin assisted, mechanical shell tensioned bolt. The remaining 10% is the 2-piece, 8-foot long, 7/8? combination bolt, which employs 4 feet of fast resin to anchor the deformed rebar at the top of the hole. In either system, a 1-3/8? hole is required to accommodate the mechanical shell and the coupler. The cheaper torque-tension rebar system, which is typically fully-grouted with 2-speed resin and which typically provides low bolt tension, is not used in CONSOL?s Pittsburgh seam mines. Rather, it is used in CONSOL?s Central Appalachia mines, where the roof rocks have CMRR rating of 50 or higher. Fully-grouted headed rebars, on the other hand, are used in CONSOL?s room-and-pillar mines. The selection of tensioned versus non-tensioned, fully-grouted bolts for coal mine primary roof support has been debated for the past thirty years. Many researches have been conducted to understand the theoretical bases behind the two systems. This paper describes CONSOL?s experience of using a new fully-grouted, mechanical shell tensioned bolt in the Pittsburgh seam with the development of low insertion force resin.

Jan 1, 2007

By Van Sint JanM., M. Prudencio

ABSTRACT We report the results of a model-testing program to evaluate the strength characteristics of non-persistent joints. We describe the conditions under which new tensile cracks generate and propagate to connect existing joints so that the rock mass becomes fractured into several blocks, leading to a low strength. The strength of some models was equal to that along a single joint through the full sample length. In models with two joint sets, failure took place along a composite plane, partly sliding along a discontinuous joint and shearing through the intervening intact block of rock, or else by rotation and sliding of the blocks. This last failure mode could also lead to very low model strength. ZUSAMMENFASSUNG Dieser Bericht beschreibt die Ergebnisse von Versuchen mit Modellfelsmassen um den Einfluâ von unterbrochenen Rissen in ihrer Widerstandsfähigkeit zu untersuchen. Es werden die Umstände beschrieben unter denen neue Zugrisse entstehen, sich verbreiten, sich mit bestehenden Rissen verbinden und die Felsmasse in mehrere Felsblöcke zerlegen und zu einer kleinen Widerstandsfestigkeit führen. Der Widerstand einiger Versuchskörper entsprach der Festigkeit eines Risses der die ganze Länge des Versuchskörpers überquert.Versuchkörper mit zwei Rißfamilien versagten unter einer zusammegesetzten Ebene, zum Teil mit Verschiebungen nach unterbrochenen Rißebenen die sich durch Schnittversagen intakter Felsblöcke verbinden, und zum Teil durch Drehungen und Verschiebungen einzelner Felsblöcke. Die letzte Versagunsart kann zu einer stark verminderten Widerstansfähigkeit führen. RÉSUMÉ Nous présentons les résultats de quelques essais fait sur des modèles évaluant les caractéristiques de résistance des fractures discontinues. Nous décrivons les conditions sous lesquelles des nouvelles fissures de traction peuvent s’engendrer et se propager pour faire la connection avec des fractures existantes, de façon que le rocher se fracture en plusieurs blocs, menant à une résistance réduite. La résistance de quelques modèles fut égale a celle d’une fracture traversant toute la longueur du modèle. Pour les modèles ayant deux ensembles de fractures, la rupture a eu lieu sur une surface mixte, causée d’une part, par le glissement sur une fracture discontinue et d’autre part, par la rupture à travers le pont de matériel intact; ou bien par rotation et glissement des blocs. Cette dernière façon de rupture peut aussi aboutir à une très faible résistance des modèles.

Jan 1, 2003

THE following brief paper is submitted with a view to encouraging the exploitation of hitherto neglected 10w~ grade ore-bodies which are suitable for extraction by open-cut methods.The Corinthian North mine, situated 10 miles from Southern Cross, in the Yilgarn district of Western Australia, furnishes an example of low working costs, although operations are carried out on quite a limited scale.The body of quartz which is now being worked strikes N.W. and S.E., has a very slight underlie to the west, and lies between bodies of quartz-hrematite s,chist on the east and amphibolite on the west.So far as the property has been explored, it would appear that the underlying sulphide rises to within about 70 ft. of the surface in the northern end of the workings, and pitches away to the south at a grade...

Jan 1, 1915

By Neil T. Davie, Thomas K. Blanchat, Thomas C. Togami, Joe R. Weatherby, Dale S. Preece, Robert A. Benham, James J. Calderone

"Geotechnical structures ,such as underground bunkers, tunnels, and building foundations aresubjected to stress fields produced by..the gravity load on the structure and/or any overlyingstrata. These stress fields may be.. reproduced on a scaled model of the structure byproportionally increasing the gravity field through the use of a centrifuge. This technology canthen be used to assess the vulnerability of various geotechnical structures to explosive loading.Applications of this technology include assessing the effectiveness of earth penetrating weapons,evaluating the vulnerability of various structures, counter-terrorism, and model validation. Thisdocument describes the development of expertise in scale model explosive testing ongeotechnical structures using Sandia’s large scale centrifuge facility. This study focused onburied structures such as hardened storage bunkers or tunnels. Data from this study was used toevaluate the predictive capabilities oft existing hydrocodes and structural dynamics codesdeveloped at Sandia National Laboratories (such as Pronto/SPH, Pronto/CTH, and ALEGRA)."

Jan 1, 1998

By John E. Wiegand

"We will attempt to explain the basic workings of a modern seismograph and how the recorded data can be interpreted, not only for determining compliance to the regulations, but also in determining whether or not a seismograph record is accurate and valid. We will discuss some parameters that should be included in all seismographic recordings. We will give examples and use overhead slidesto show examples of both accurate and valid recordings, and tampered and inaccurate seismograph recordings. Much of the information presented will be basic in nature, and will reflect the opinions and personal experiences of the author. We ho'pe the listener will gain valuable information concerning the use and interpretation of seismographic data, as well as find interest and sometimes humor in the examples shown."

Jan 1, 1992

By H. R. Butler, J. F. Church, A. T. MacGibbon

Introduction Inco is the major North American nickel producer. Initially based in Sudbury, Ontario, its past exploration activity was directed toward finding new nickel deposits. New nickel sulfide discoveries outside Sudbury have included Thompson, Manitoba; Shebandowan, Ontario; and Widgiemooltha in Western Australia as well as a host of nickel laterite deposits. The company is currently diversifying into other commodities, including gold. Inco's exploration department participated in uranium discoveries in Saskatchewan and chromite discoveries at Tiebaghi in New Caledonia. In addition, it found new gold deposits at Lupin, Northwest Territories; Crixas, Brazil; Hoyle Township, Ontario; and Casa Berardi in Quebec. Crixas and Casa Berardi are currently being evaluated by underground exploration. Figure 1 shows some Canadian Shield gold locations where Inco is or was an active participant. Base metal developments Base metal exploration in shield areas has been greatly eased by applying scientific studies. Archean nickel sulfide deposits have been found using komatiitic-flow models (Fardon, 1971). Volcanogenic massive sulfide model has been applied to copper-zinc deposits (Sangster and Scott, 1976). Such deposits were subsequently seen developing on the sea floor through black smokers (Spiess, MacDonald, and Atwater, 1980). Sedimentary processes were recognized early as important in ore formation, particularly in the southern hemisphere (King, 1976). And many ore deposits are now regarded as a simple part of the geological column (Stanton, 1960 and 1972). Petrographic work on alteration patterns in and around ore bodies was used to develop standard porphyry copper models (Lowell and Guilbert, 1970). Epithermal models for precious metals followed. Stratigraphic zonation patterns have been formulated for base metal deposits, including keel facies, ore facies, and cap or distal facies. Gold developments The work on base metal deposits naturally spilled over into precious metal exploration when the gold price was allowed to float on world money markets. Early work on elements associated with gold deposits, especially arsenic, tellurium, selenium, and mercury, pioneered more detailed geochemical work (Bagby and Berger, 1985; and Groves, Ho, and Houstoun, 1984). Geochemical patterns have been recognized around microfine gold deposits. And the study of gold precipitation patterns in modern geothermal systems has helped understand gold deposition. In the late 1960s and early 1970s, it was noticed that numerous Archean banded iron formations contained anomalous gold values. From this and other observations, the syngenetic exhalite gold model has developed. Gold deposits also occur along shears in some plutons such as the Belmoral mine in Quebec. This indicates the importance of epigenetic processes in ore formation. Shield ore settings Initial studies recognized that the major gold camps in the Canadian Shield were mostly in greenstone belts and found along "breaks," especially zones of faulting and sedimentation. Gill (1948) wrote, "Only recently, as a result of detailed mapping, has the importance of major schist zones such as the Larder Lake, Cadillac, Porcupine Creek, and Destor Breaks been recognized. These zones of persistent adjustment mark broad belts favorable for ore occurrence." The importance of shearing in ore location and regional greenstone stratigraphic position close to late sedimentary packages was clearly understood. And structural models have been further developed for some Canadian ore deposits (Hubert, Trudel, and Gelinas, 1984). In the Beardmore-Geraldton camp of northwest Ontario, the importance was soon recognized of fold noses in banded iron formation, as localizers for gold ore. This importance had also been recognized in Western Australia,

Jan 2, 1987

While SME is hosting its Annual Meeting at the Phoenix Convention Center, Feb. 28 to March 3, one of the finest collections of mining history will be on display just 15 blocks away at the Arizona Mining and Mineral Museum. Inside the museum, visitors will be treated to a treasure trove of minerals, gems, me¬teorites, rocks, fossils, mining artifacts, historical exhibits and interactive displays on modern mining. The museum is located at 1502 West Washington. For SME Annual Meeting attendees, this is a free, eight-minute Dash bus ride 15 blocks west of the Phoenix Convention Center.

Jan 1, 2010

By L. K. Weaver

The Bureau of Mines has started an engineering study of oil recovery by miscible-phase displacement. As a preliminary part of the investigation a literature and patent study was made to prevent duplication of work already done, to become acquainted with those actively engaged in research of this type, and to learn where the recovery method has been attempted. This bibliography gives results of this study. The bibliography includes 254 references to U.S. and foreign patents and published literature relating to miscible-phase displacement processes of oil recovery. It is divided into the following sections: (1) U.S. patents, (2) foreign patents, (3) literature references, (4) author index, and (5) publication and source reference. The patents and literature references are listed alphabetically by author by intervals of years. References to February 1963 are included.

Jan 1, 1963

By R. R. Allen

[The utilization of Western coals and lignite is a continuing study of the Bureau of Mines, and storage of these fuels is of paramount importance. Since the seasonal demand for coal in the Western States triples between the summer and winter months, successful storage of these low-rank fuels would tend to level out this variation and should reduce fuel costs. The time is rapidly approaching when the West Coast States, particularly California, will annually import several million tons of coal from the Rocky Mountain States for additional power production. This will necessitate storage of large quantities of coal, and it is thefore important to develop experience in such storage. Dry surface storage, by virtue of its flexibility and low cost, is particularly adapted to the stockpiling of large quantities of coal. This report will, therefore be primarily concerned with such storage. Inasmuch as the problems of dry, open-pit storage are quite similar to those of surface stockpiling, experiences in pit storage will be discussed briefly. Although spontaneous combustion is a hazard in storing coal, experience has proved that heats can be avoided by proper stockpiling procedures. The purpose of this report is to show that the most reactive coals can be stored satisfactorily on the surface by avoiding segregation and by thorough compaction.]

Jan 1, 1954