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By Paul Worsey, Seokbin Lim

There are two major types of shaped charges, conical and linear (Ref 1, 2). Conical shaped charges are used to perforate targets and are mainly used by the military as anti armor weapons and by the oil industry for oil well perforation. In contrast, linear shaped charges are primarily used to cut metal in the demolition industry with other uses including separating devices in the space industry. There is a large amount of material published on conical shaped charges because of the high level of defense industry research and funding, however in stark contrast there is very little published on linear shaped charges.

Jan 1, 2003

By C. Sawmliana, P. Pal Roy

Near-field blast vibration response of restrained pipelines either buried or exposed was studied during rock excavations at sensitive locations for Stage-II (4x500 MW) commissioning work in a super thermal powerplant of the National Thermal Power Corporation Ltd. (NTPC) of India. The existing running plant of capacity 1000 MW has many important installations including pipelines of varying diameters. These pipelines were very close to the blasting locations (mostly within 12m). Blast optimization and consequent monitoring of vibrations were carried out simultaneously for more than 250 experimental blasts conducted by the authors. This paper emphasized, particularly, on the safety of pipelines and their responses due to repeated blasting impacts. A few guidelines supported by theoretical derivations are provided for futuristic research.

Jan 1, 2001

By A. W. Popp

After forty years of exploration and development, the heavy mineral sand deposits of the Murray Basin are on the eve of substantial exploitation by Iluka Resources Limited, Southern Titanium NL and RZM/Cable/Bemax, whom plan to initiate mining and processing operations in 2005. A trial mining and processing operation was undertaken on the Wemen North strandline deposit in 2001-2003 by Murray Basin Titanium, a joint venture of Sons of Gwalia and RZM/Cable, which brought to light a number of mining and processing problems which have since been the subject of extensive studies and process development work. The mineralogy of these weathered strandline deposits is complex by industry standards due to the variety of the heavy minerals present, coatings on the mineral grains and the extensive weathering and alteration which has taken place during the past 50 million years. This paper provides an overview of the complex mineralogy that, in turn, dictates the processes that can be used to recover the valuable heavy minerals. The Murray Basin encompasses some 300,000 km2 and has been a depositional basin, often land locked, since the start of the Cenezoic Era. The economic heavy minerals include ilmenite, altered ilmenite, leucoxene of highly variable composition, rutile, and zircon. There are also other heavy minerals present such as cassiterite, chromite, and monazite in quantities that pose both problems and opportunities. The clay content and overburden thickness also play a major role in the selection of the deposits to be mined. Project Services Consultants (PSC) has undertaken the preparation of this paper as part of its ongoing participation in the mineral sands industry and in particular the project development activities in the Murray Basin region currently being undertaken by Iluka Resources. PSC has been involved with the mineral sands business for several years with senior staff having in excess of 30 years global industry experience. The company is well placed to provide a range of services to clients like Iluka Resources in the areas of project development, execution and strategic development and industry advice.

Jan 1, 2005

The southern portion of the Swan Coastal Plain, a geomorphological element formed since late Tertiary times, contains commercially exploitable accumulations of ilmenite, zircon, rutile and monazite associated with a series of raised shorelines. The location of the deposits is controlled by a locally outcropping Archaen granite/ granulite complex and a sea current pattern determined by local geography and a prevailing wind direction. A progression from medium to high titanium ilmenite is evident parallelled by progressive leucoxenisation as the age of the deposits increases. Variations in trace element content accompany this process. Circulating groundwater has caused vertical mineralogical variations within individual deposits and by precipitation of iron has formed layers of hardpan.The Geographe Bay deposits are of important economic significance.INTRODUCTIONObservations made during the course of a brief survey of the southern portion of the Swan Coastal Plain provide an outline of the geology and mineralogy of the mineral sand deposits of the area. This preliminary study will require considerable modification in the light of more detailed work in the future.REGIONAL GEOLOGYThe Geographe Bay area is situated in the south-west corner of Western Australia between longitudes 115° O'W. and 116° O'W. and latitudes 33° 15'S. and 33° 45'S.The general geology of the area is shown in Fig. 1 where the control of the physiography exercised by the Cape Leeuwin-Cape Naturaliste basement ridge is readily apparent. Between this ridge and the Precambrian east of the Darling fault lies the southern part of the Perth basin which contains outcropping Jurassic to Recent sediments and lavas (McWhae, et al., 1958).The Leeuwin-Naturaliste ridge is the exposed portion of L Assistant Production Managcr. Laporte Titanium (Aust.) Ltd.

Jan 1, 1964

By N. D. L. Burger

A low noise blast hole drilling system was developed to limit the risk of noise-induced hearing impairment in mining operations. Noise- induced hearing loss has been identified as a major occupational health risk in SA mines. The noise generated by pneumatic percussion drills is a major contributor to such noise-induced hearing loss. This motivated the South African Safety in Mines Research Advisory Committee (SIMRAC) to commission the development of a low noise rock drill system. The system had to be designed, manufactured, tested and demonstrated in a simulated underground mining environment. The specification required noise levels below 90 dBA. Other important design considerations were ease of manual transport, setting up and operation. The primary design concept was to encapsulate a standard SecoS215 pneumatic rock drill in a composite material tube. The tube is pushed onto the rock face by a pneumatic cylinder and is sealed at the rock face by an elastic seal. The drill is pulled towards the rock face by a rope and pulley mechanism fitted inside the tube. This mechanism is powered by a second pneumatic cylinder. The actions of moving and setting the drill require two persons. However, the team can carry out the drilling function itself on several drills simultaneously because of the self-thrusting design. The drill is supported by two camlocks. The exhaust (air containing dust, water, rock debris, oil and grease) is removed from the encapsulating tubes via an exhaust tube to the end of the stope. In this way exhaust noise and air pollutants are disposed of away from personnel. Tests were conducted in a test stope. Noise levels of under 90 dBA were achieved, thereby attaining the primary design specification. This was achieved without materially compromising ease of handling. Penetration rate was somewhat improved compared to that of the standard drill, so that productivity could be maintained. Keywords: Drill, rock drill, quiet, noise, mine, underground.

Jan 1, 2004

By M. Dobbins

The advent of the more efficient and effective rare-earth roll (RER) separator in the early 1980s began a new era of dry magnetic separation. The RER units quickly became the separator of choice within the materials processing industry. Though RER separators are now commonplace throughout the world, only modest advancements have been made to the original design. This paper details recent, more significant, rare-earth magnetic separation developments. These developments maintain the best features of existing technology while minimizing shortcomings. The discussion includes discerning features that aid in better metallurgical performance. Also discussed are improved mechanical aspects that allow for both easier operation and maintenance. Performance details from various test programs are included.

Jan 1, 2010

By Roy G. Stott, John A. Johnson, Floyd G. Anderson

"This information circular discusses drilling and blasting in open-cut iron-ore mines and is one of a series of papers describing iron-ore mining practices in the Lake Superior district to aid in preventing accidents in that industry.The Lake Superior district consists of the Marquette and Menominee ranges of Michigan, the Gogebic range of Michigan and Wisconsin, and the Vermilion, Mesabi, and Cuyuna range of Minnesota. Open-cut mines produce 8o percent of the iron ore mined in the district; 98 percent of the total Lake Superior district open-cut ore is produced in Minnesota and 2 percent in Michigan. The entire Wisconsin iron-ore production is from underground nines. The Mesabi range in Minnesota produced 93 percent of the open-cut iron ore and 76 percent of the total iron ore in the district in 1947.During the 8-year period 1940-47, 619,000,000 gross tons of iron ore were shipped from mines of the district, or 85 percent of the United States output. Approximately 78,000,000 gross tons of iron ore were shipped from the mines of Minnesota, Michigan, and Wisconsin in 1947.This paper is based primarily on observations daring the period July 1947 to March 1948. Thirty-two open-cut mines were visited; 28 on the Mesabi range, 3 on the Cuyuna range, and 1 on the Marquette range. In 1947, 36,100,000 tons of iron ore was shipped from these 32 mines, or 59 percent of the open-cut ore and 46 percent of the total iron ore shipped from the district. During 1947 about 90 open-cut iron-ore mines were operating in the district, and the annual production of each ranged from 25,000 to 10,000,000 tons.Many recommendations included in this paper for improving safety and preventing injuries to employees were taken from Bureau of Mines Information Circular 7387.Data were collected under the direction of Frank E. Cash, former supervising engineer, Health and Safety Division, Bureau of Nines, Duluth, Minnesota. E. W. Felegy, mining engineer, Safety Branch, gave valuable assistance in reviewing and editing the manuscript.The authors gratefully acknowledge the information and assistance given and the numerous courtesies extended to them by officials of the following mining companies:All the Lake Superior iron ores occur in bedded formations that range from less than 100 feet to over 2,000 feet in thickness. These formations are designated by one commonly applied name, ""iron formations.""4/The Mesabi range in northern Minnesota, about 70 miles northwest of Duluth, was opened to mining in 1892; it is the largest single source of iron ore in the United States. It is 75 miles long and, because of the gentle dip of the ore formation, it ranges in width from 1-1/2 to 3 miles.5/ The ore formation, which is nearly horizontal, has a maximum thickness of about 450 feet and is covered by a glacial drift that ranges from 10 to over 100 feet in thickness. Most of the ore is near the surface and adaptable to open-cut mining."

Mar 1, 1950

By Egil Aukrust

"An American Iron and Steel Institute Task Force evaluated developing direct steelmaking technology worldwide to seek a replacement for the coke-oven, blast-furnace, basic-oxygen process technology now in use. To remain internationally competitive it is essential to move away from the traditional series of batch processes towards continuous processing and the associated energy savings which are possible with high technology process control systems. The group identified in-bath smelting of iron ore pellets or fines with coal as the process most sui table for domestic raw materials (including abundant scrap) and called for research to study operation with varying degrees of preheat and prereduction of the ore by the gases generated from the coal and various degrees of combustion of these gases above the melt.A coordinated, 3-year, $27 million, direct steelmaking research program is proposed. Concurrent projects include design, construction, and experimental operation of an in-bath smelting pilot plant; modeling, simulations, and laboratory-scale experiments at universities on slag-phase and metallicphase reactions and interactions; and large-scale heat transfer and reaction rate trials. Also included are modeling studies and pilot plant trials of on-stream decarbonization and desulfurization; application of circulating fluid bed technology to fine ore reduction and hot gas cleanup; and specific heat transfer and fluid flow research projects.IntroductionThe American Iron and Steel Institute (AISI), based on the Task Force studying direct steelmaking, believes strongly that a coordinated program of research on the reduction of domestic raw materials to liquid steel should be undertaken as part of the Steel Initiative program. To specify the steelmaking process for development best suited to the American steel industry and domestic raw materials, it was important to determine the state-of-the-art of direct steelmaking worldwide, both as practiced and under development, and then, by expert analysis of the processes and their potentials, to choose the process most likely to provide a domestic competitive edge."

Jan 1, 1988

By Ed Clah, Catherine Aimone-Martin

The vibration response of a 30 in. diameter high-pressure (845 psi) natural gas pipeline to 11 coal mine blasts was measured. The X-52 steel pipeline was buried 7 ft. below the ground surface. Ground and pipeline motions in terms of velocities were recorded on the pipeline, in the ground adjacent to the pipeline, and near the ground surface directly above the pipeline. These data were used to estimate the maximum stresses and strains in the pipeline occurring during the blasts. Pipeline standoff distances varied from 264 ft. to 3720 ft. Two blast hole layouts and timing schemes were used. One represented highly confined blasts to limit movement of the shot overburden that generated high ground motions at the pipeline. The second represented patterns that provided greater relief and lower the ground velocities at the pipeline.

Jan 1, 2003

By Edmund J. Cardoza

WELCOME TO THE DEEP FOUNDATIONS INSTITUTE 26TH ANNUAL CONFERENCE AND WELCOME ESPECIALLY TO THIS SEMINAR ON NON-DESTRUCTIVE TESTING OF DRILLED SHAFTS, PRESENTED BY MEMBERS OF THE DFI DRILLED SHAFT COMMITTEE. MY NAME IS ED CARDOZA; I AM A VICE PRESIDENT WITH THE MILLGARD CORPORATION, A DRILLED SHAFT CONSTRUCTOR FOCUSING PRIMARLY IN THE EASTERN HALF OF THE UNITED STATES.

Jan 1, 2001

By K. T. Lee, M. U. Ozbay, M. D. G. Salamon

Design of yielding chain pillars in deep coal longwall mines is not as well established due mainly to the lack of knowledge in the behavior of coal pillars in the post-peak regime. This study shows that two of the existing strain-softening models have the potential to provide an improved understanding of yielding and, therefore, could form a rational basis for yielding coal pillar design. Analytic and numerical modelings of a row of chain pillars in a two-entry development at a depth of nearly 700 m suggests that yielding pillars are feasible, but the design is very sensitive to the coal’s post-peak behavior.

Jan 1, 2001

This paper is concerned with the blasting of rock in mining. The most common purpose of blasting rock is to cast it or to disrupt its structure sufficiently for effective digging and subsequent removal.

Jan 1, 1991

By A. M. R. Neiva

The WNW-ESE-trending hydrothermal veins cut alternating mica schists and quartzites of mainly Ordovician age and, to the west, a Hercynian muscovite-biotite granite. They have been prospected and developed to a depth of 300 m and reserves of 20 t Au estimated. The paragenetic sequence and chemical compositions of the ore minerals are generally similar to those at Jales to the south. Gold, electrum and aurian silver form inclusions in arsenopyrite, pyrite, galena, sphalerite, pyrrhotite and quartz and also occur in veinlets that cut these minerals. Silver has been found in gold, electrum, aurian silver, tetrahedrite, freibergite and the Ag-Pb-Sb sulphide owyheeite. Early arsenopyrite crystallised at an estimated 480 degrees C and the more common, later arsenopyrite in which Au and Ag are generally included at 430-300 degrees C. Sphalerite crystallised at 307-100 degrees C. Monoclinic pyrrhotite may have been formed by the inversion of hexagonal pyrrhotite at 248 degrees C

Jun 16, 1905

By Paul C. Schmall, John F. Donohoe, Arthur B. Corwin, Derek Maishman

Ground freezing was utilized to provide complete stability of the excavation face and complete groundwater cut-off for the jacking of the three tunnel boxes for the Interstate 90 / Interstate 93 approach to the Fort Point Channel crossing. Through a wide range of geological conditions and large buried obstructions, the freezing provided complete stability of the face so that a 11.5 m (38 ft) high free standing vertical face could be mined without the need for any additional face support. Obstructions were incorporated into the massive frozen ground matrix, and held in place so that they could be excavated with a minimum of disturbance. The freezing provided an absolute groundwater cut-off, and permitted the work to be done without disturbance to the active rail system immediately above. With the use of instrumentation such as borehole thermocouples, the effectiveness of the freezing was guaranteed and the jacking proceeded with complete confidence and assurance of the ground conditions ahead.

Jan 1, 2001

By A. S. Macfarlane

This paper describes how knowledge of the orebody morphology and ore morphology can be used to optimize the planning, mining, and metallurgical output from an open pit copper mining operation, such as to significantly increase the stability of the whole value chain process, and increase the reliability and value of the process outputs. In the case under consideration, the orebody contains both copper and cobalt. This in itself provides a challenge, in that the two metals do not occur in consistent ratios across the orebody as a whole. Furthermore, mineralogical differences within the orebody have a significant impact on plant performance in terms of throughput rates, acid consumption, and recoveries. In order to stabilize and optimize the plant performance, it is necessary to firstly have a complete understanding of the geometallurgical factors that affect performance, and then to have a sound knowledge of how these are distributed within the orebody. These models then inform the mine planning strategy that optimizes cash flow and NPV, and also allow the development of a stockpiling strategy that not only stabilizes the plant, but also allows variations in the plant feed according to ore type and grade in volatile price scenarios. Integral to the realization of these opportunities is the establishment of an appropriate measuring, control, and reconciliation system, customized to the optimization objectives. The paper describes how all of these factors and strategies can be integrated to produce optimal value from the orebody through to final dispatched product. It also shows the significant value that can be released through such an approach.

Jan 1, 2014

By Bhaskar B. Thapa, Christopher Laughton, Michael P. Bruen

At Fermilab, located in Batavia, Illinois, a 4,000-foot underground complex of tunnels and caverns is being excavated on a decline of six percent, at depths of up to350 ft, below grade. The site geology consists of dolomitic and shale formations overlain by glacial till. Since the start of construction in March 2000, work to date has concentrated on the excavation and support of the Target Hall cavern, which is characterized by a low rock cover and a final lining of shotcrete. Ground vibrations, noise levels, and rock movement were monitored during excavation by drill and blast methods to prevent damage to experimental facilities, impacts on surrounding communities, and to allow evaluation of cavern performance. The cavern design was based on a UDEC numerical analysis that was validated during construction by comparison to encountered conditions and measured cavern movements.

Jan 1, 2001

By A. E. Raddatz

The Bureau of Mines is investigating methods for recovering tungsten from domestic resources. A calcine-quench-leach (CQL) technique was developed for the extraction of tungsten from the Golconda, Nev., hot springs ores. The deposit contains disseminated tungsten that cannot be beneficiated by conventional techniques and must be treated by hydro-metallurgical methods. The CQL procedure consists of calcining the ore at 900° C for 3 hours, quenching in a solution containing 1.5 parts of Na2C03 and 1.5 parts of NaOH per part of WO3 in the ore and at a solution-to-ore ratio of 3 to 1, leaching at 200° C and at 250 psig for 3 hours, and filtering and washing the residue. A series of closed-circuit batch tests showed that 92 pct of the tungsten was extracted from a sample containing 2.32 wt-pct W03. The pregnant solution contained 11 g/l W03.

Jan 1, 1982

By BUREAU OF MINES

This report is submitted in accordance with provisions of the Synthetic Liquid Fuels Act of April 5, 1944 (30 U. S. C. 321-325, as amended), which require that: "The Secretary of the Interior shall render to Congress on or before the first day of January of each year a report on all operations under this Act." Owing to the broad scope of the content and the diversity of interests represented, the Annual Report for 1954 has been divided into two separate publications. Each is being published by the Bureau of Mines as a Report of Investigations, and the respective titles follow: R. I. 5118, Part I - R. I. 5119, Part II - 011 From Coal. 011 From 011 Shale. The introduction, identical in both reports, summarizes research progress in 1954 under the entire Synthetic Liquid Fuels program. A free copy of either publication may be obtained by writing to the Bureau of Mines, Publications Distribution Sec- tion, 4800 Forbes Street, Pittsburgh 13, Pa. The R. I. number and title of the publication desired should be indicated.

Mar 1, 1955

By T. Ogasawara, J. P. Barbosa, A. J. Monhemius, F. T. Da Silvia

A thermodynamic analysis of the sulphation of rare-earth phosphates and the water-leaching of rare-earth sulphates was used to guide experimental work on the sulphation and leaching of concentrates from Pitinga. It was concluded that the sulphuric acid digestion of xenotime is technically feasible and could be used industrially to produce yttrium and other rare-earth oxides. Yttrium extractions of more than 90% were obtained by digestion at 503 K for 4 h at an acid:concentrate ratio of 2:1 with particle size -0.053 mm. The apparent activation energy at temperatures less than 473 K, as determined from the Arrhenius plot, was 11.0 kJ/mol, indicating that the reaction is controlled by the diffusion of the reactants or products through the sulphate layer

Jun 19, 1905

By M. Sturzenegger

This paper documents a field survey using long-range terrestrial digital photogrammetry at the Palabora open-pit mine, South Africa, for multi-scale characterization of rock mass discontinuities. Stereomodels covering the entire mine were generated based on photographs taken from a distance of 1600m across the pit, using a series of f=20-400mm lenses. Details on the methodology used and its accuracy are discussed. Preliminary results on discontinuity orientation, persistence and intensity are presented, highlighting the effect of observation scale. The potential uses of long-range terrestrial digital photogrammetry in open-pit mine and large natural rock slope environments is emphasized. The use of an f=400mm lens from distances larger than 1.5km may represent an important step forward in the geotechnical characterization of inaccessible remote rock faces.

May 1, 2009