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By Forrest T. Moyer

To keep the mineral and allied industries informed of trends in the causes of accidents and to point, out the need for corrective measures, the Bureau of Mines collects, analyzes, and periodically publishes health and safety statistics. This report includes data for 1962 on injury experience, with related employment statistics, at coal mines in the United States. These data are presented in tabular form under the following: General Injury Experience Tables 1 to 6: Current data on number of injuries, degree of injury, frequency and severity rates, average severity, and related employment and production data by work location.

Jan 1, 1964

By Forrest T. Moyer

To keep the mineral and allied industries informed of trends in the causes of accidents and to point out the need for corrective measures, the Bureau of Mines collects, analyzes, and periodically publishes health and safety statistics. This report includes data for 1962 on injury experience, with related employment statistics, at coal mines in the United States. These data are presented in tabular form under the following: General Injury Experience Tables 1 to 6: Current data on number of injuries, degree of injury, frequency and severity rates, average severity, and related employment and production data by work location.

Jan 1, 1964

By STUART R. BRINKLEY, Ruth F. Brinkley

This same phonomonon of diffraction may be transposed into the X-ray domain. All that is necessary is to reduco, in the samo proportion, the wavo length of the light and the diameter of the particlo; thus, with radi- ations whose wave length is of the ordog of angstroms, the dimensions of the active particles go from 10 to 100 A that 18, the dimensions of col- loidal particlos. The evidence of this fact is shown by the following experimental schomo (fig. 1a): A narrow beam of X-rays passes through a thin layer of a modium containing micelles; the photographic film is placed a few centimeters behind the sample, and a small absorbing screen stops the direct beam in order to prevent its fogging the film. The intersect of the direct beam is surrounded by a narrow spot whose blackness decreases with the distance from the center. We will call this the spot of central diffusion (fig. 1b). The phenomenon, in spite of its relatively reat intensity, has been observed only by a few authors, who have simply given a qualitative description without attempting any quantitative de- ductions. This is due to the fact that observation of this phenonenon is not possible with the apparatus generally used to obtain X-ray diagrams, because the parasite foggings in the vicinity of the incident beam are sufficiently important to hide those produced by the sample. With the monochromator, however, used by us to obtain Debye-Sherer diagrams, this parasitic diffusion can be totally suppressed. In this way our attention was again directed to the spot of central diffraction, and we were led to make a detailed quaititative study of it.. then several papers have been published on this subject. Hosemann, using methods of calculation outlined by us, has extended them to the special case of fibrous substances, Kratky, on the other hand, starts from an entirely different theoretical point of view; ho examines the case, not of scattered particles, but of closely packed particles. 6ince We will now describe the experimental methods, summarize the calcu- lations needed in the elaboration of diagrams, and finally review the first results obtained in the vast domain of these new physical-chomical studies.

Dec 1, 1946

By Gerald Verbeek, Erick Baziw

Stone columns are used in geotechnical site remediation to increase load-bearing capacity and reduce settlement of foundations. Stone columns also improve slope stability and increase the shear strength of a soil. A very challenging problem is to characterize the in-situ shear wave velocities from data acquired from Downhole Seismic Testing (DST) after the insertion of stone columns. DST is an important geotechnical testing tool for site characterization that provides low strain (<10-5) in-situ interval compression and shear wave velocity estimates, but the postanalysis of seismic data acquired from DST in the presence of stone columns is very challenging due to the resulting complicated in-situ soil conditions. To obtain the right results it is necessary to use an algorithm that incorporates source wave raypath refraction. Starting with the Normal Moveout Seismic Cone Tomographic Testing (NMO-SCTT) algorithm developed some years ago, this paper outlines the modifications and additions made to this NMO-SCTT algorithm to facilitate stone column site characterization. To dramatically reduce the optimal solution space for the estimated interval velocities the paper also described a priori conditions that are applied based on the unique nature of the stone column site conditions.

By W. D. Hausel

The Wyoming craton in the western United States is a favorable terrane for diamond deposits. The craton hosts a variety of ultramafic, ultrabasic, and ultrapotassic rocks. Additionally, a few hundred &apos;kimberlitic&apos; heavy mineral anomalies and some geophysical and remote sensing anomalies indicate the presence of undiscovered, mantle-derived, pipes in the craton. The Wyoming craton is separated into a Wyoming &apos;archon&apos; known as the Wyoming Province, and the Colorado &apos;proton&apos; known as the Colorado Province. The &apos;archon&apos; underlies much of Montana and Wyoming and continues north into Alberta and Saskatchewan; the Colorado &apos;proton&apos; underlies much of Colorado and a small portion of Wyoming. Although most exploration geologists would consider the &apos;archon&apos; the most favorable terrane for commercial diamond deposits, the &apos;proton&apos; has produced more than 120,000 diamonds, while the &apos;archon&apos; has not been very productive.

Jan 1, 1996

By Larry G. Stolarczyk

An underground medium frequency radio communications system has been developed and demonstrated in both coal and metal/non metal mines. The principal advantage of the system are its low cost, ease of installation and the ability to provide radio communications to any vehicle or roving miner in the underground mine. The system provides high quality radio coverage in work areas and along manways with existing "wireplant" conductors. The conductors include AC power cable, telephone cable, metal water and high pressure air pipes, etc. The measured communications range from the base station to mobile transceiver exceeded 12,500 ft without the use of repeaters. A cost/benefit analysis shows that the initial cost of the equipment can be returned 2-6 times in the first year. The mine productivity increases by approx. 13 percent.

By R. E. Johnson

The No. 3 reverberatory furnace at Phelps Dodge. Corporation&apos;s Morenci, Arizona copper smelter first received oxygen from a new oxygen plant during October 1982 and began operation with oxygen-fuel and oxygen sprinkle smelting burners which burn concentrate with oxygen. The furnace was completely converted to roof-mounted oxygen-fuel firing in October 1982. All conventional air-fuel bridge wall burners were extinguished at that time. The novel arch-mounted oxygen sprinkle smelting system began continuous operation April 1983. Since startup, unit fuel requirements decreased and furnace throughput significantly increased. Furnace off gas SO2 strength increased from an average of 1.5% SO2 to an average of 20% using only oxy-fuel burners. Oxygen sprinkle burner operation also has given excellent results, with the furnace off gas strength increasing to 35%-60% S02. There has been a reduction in overall arch temperatures, an increase in matte and slag temperatures, and a lowering of furnace bottom buildup with oxygen smelting. Furnace off gas is blended with converter off gas and treated in a sulfuric acid plant.

Jan 1, 1983

By Werner Ruegg

El presente texto describe algunos aspectos y propiedades de índole mineralógico, genético e individual de los diferentes yacimientos fosfatados. Existe una diversidad de fosfatos combinados como calcio, fluor, hierro, etc pero están aquellos también que son usados para fertilizantes limitados a los fosfatos cálcicos. De éstos, la apatita es su forma cristalina primaria, constituyéndose como la fuente de combinaciones. La fosforita, a su vez, es su contraparte amorfa, que establece un precipitado químico o un residuo orgánico donde existen combinaciones entre los dos.

Mar 1, 1984

By Kenneth H. Johnston

This report describes an in situ combustion project and three waterflood projects in Allen, Anderson, and Wilson Counties, Kansas, that will be visited during the 1964 annual tour of the Kansas-Oklahoma Waterflood Association. Among the unique features of the projects are the movement of heavy crude oil through the reservoir and into the wellbore with energy furnished by burning s portion of the crude oil therein. Another feature is the simultaneous injection of C02 and water, through separate tubing into input wells during early development, to increase injectivity at moderate pressures, Discussion of individual projects includes information on their early history, source and treatment of injection fluids, oil production-decline curves, and the results of water injection on oil production.

Jan 1, 1964

By Ricardo A. Valls

The Sechol Nickel-Cobalt Laterite Project is located in East-Central Guatemala, 140 km northeast from Guatemala City. In-situ resources in the immediate Sechol area, including those on other mining concessions contain 133 million tonnes of mineralization, grading 1.5 1% nickel. Considering the ever-increasing market for these metals, and the potential quick return on the initial investment, Jaguar Nickel Inc. is confident that by late 2006, it will be producing the first nickeltcobalt hydroxides from Guatemala. The path from now until the production stage passes through a pre-feasibility study, scheduled for completion by mid 2004, and bankable feasibility by mid 2005. Jaguar&apos;s objective, however, is not only to have a producing nickel-cobalt mine by late 2006, but also to continue with the exploration work in order to make Guatemala one of the world&apos;s leading nickel-cobalt producers. The Sechol group of deposits is conformed of several lateritic pockets, delimited by tectonic faults, and hosted by ultramafic rocks of the Sierra de Santa CW. ophiolitic belt that intruded the Maya Continental Block during the Early Tertiary age. The intrusive is mainly represented by a layered sequence of dunites, peridotites, and pyroxenites, usually strongly serpentinized. Existing data indicate that these rocks underwent fractional crystallization, and probably some degree of magma mixing and contamination previous to their main tectonic event. The most complete profiles are usually present over weathered dunites and serpentinites, while on top of the less altered pyroxenites, there is usually the formation of only a limonitic zone. The relative complexity of the ophiolitic belt explains the variety of mineral resources in the area, which include Ni-Co-Fe laterite, chromite, bauxite, magnesia, and also has the potential for gold, PGMs, and precious and semi-precious stones such as jade, nephrite, and chrysoprase. Metal recovery from the Sechol deposit will be based on an atmospheric chloride process, followed by solution purification, production of an intermediate nickellcobalt hydroxide suitable for sale, and finally acid and magnesia recovery by standard spray roasting technology. The chloride process will allow exploitation of the whole lateritic profile to produce 20,000 Mt of nickel hydroxide and 800 Mt of cobalt hydroxide per year. The exploration work completed to date has concentrated mostly on the Sechol group of deposits, representing less than 5% of the current land position of Jaguar in Guatemala. Within Sechol, the company has identified a large pocket of more than 5 Mt of laterites grading 2.1% nickel and 0.08 % cobalt as a startup pit "El Inicio". Including the work previously completed Keywords: Laterite deposits, Ophiolitic Belts, Central Guatemala, Nickel, Cobalt

Jan 1, 2004

"Acid resistant brick lined autoclaves and related vessels are utilized in pressure oxidation for the recovery of gold, copper, and other metals. The combination of the corrosion resistant membrane, acid resistant brick, mortar and steel shell is a composite system that requires a sophisticated stress analysis. In order to obtain meaningful results both the model and physical properties of the materials must be carefully selected. Evaluation of the calculated results requires an understanding of both the failure mechanisms of ceramics and experience with the performance of existing lining systems.INTRODUCTIONAcid brick lining systems are used in pressure oxidation autoclaves and related vessels to provide thermal and mechanical protection for corrosion resistant membranes that are applied directly to the interior of the vessel shell. The acid brick and mortar must be resistant to the process conditions and must provide a mechanically reliable structure.The construction of lined vessels incorporates a wide range of materials that can include the carbon steel vessel, austenitic weld overlay, lead lining, organic membrane, ceramic brick, mortars and other alloy components. The physical properties of the materials can vary by orders of magnitude and when combined in the construction of the lined vessel create a complex composite structure. The materials may be bonded together or act independently of each other. Stresses are induced into the lined vessel include pressure, thermal expansion, chemical expansion and mechanical loads.The complexity of these systems makes it is very difficult to account for all of the variables in the structural analysis of lined vessels. Historically calculations were simplified and designers primarily relied on experience with previous applications.The greatly improved tools for Finite Element Analysis (FEA) available today allow for detailed calculation of the stresses imposed on the vessel shell and lining. Koning & Lauzon (2004) presented a paper on design fundamentals including a discussion on the application of FEA methods at Pressure Hydrometallurgy 2004 in Banff. When a designer carefully constructs a model and selects the correct materials properties for the calculations, meaningful and useful results can be achieved."

Jan 1, 2012

By M. G. Corson

THE iron-silicon alloy series has always been one of the most puzzling among the binary alloys. Examining the well known mechanical properties of the iron-rich alloys only we meet the following situation: The ultimate strength and yield point of alloys worked and annealed under the usual conditions represent nearly a straight line function of the silicon content up to 4.5 per cent. silicon (Fig. 1). Starting at the ultimate strength of 35,000 lb. and at a yield-point of 16,000 lb. for pure electrolytic iron, one reaches a -maximum strength of 93,000 lb. and a maximum yield point of 74,000 lb. at 4.5 per cent. silicon. This corresponds to an increase in ultimate strength by 13,000 lb. per each per cent. of silicon added and nearly the same rate applies to the yield point. The data mentioned are taken from the investigation by T. D. Yensen,1 and while they do not exactly corroborate the results obtained by earlier investigators, they seem to be the most correct. Plastic properties of the alloys are controlled by a much more complicated relationship. Up to 2.5 per cent. Si, the elongation stays close to 50 per cent. (in 2 in.) and the area reduction amounts to 85 per cent., a situation that forms the usual feature of all alloys representing strictly solid solutions. The plasticity of the latter is always nearly equal to that of their base metal. Beyond 2.5 per cent. silicon, the situation becomes much more complicated Yensen observed an enormous drop in elongation and area reduction at about 2.65 per. cent. silicon, where the first hardly reaches 10 per cent. and the second is still lower; he found, however, a considerable recovery in plasticity at about 2.8 per cent. Si and up to. 4.5 per cent. Si it is represented by 20 per cent. for the elongation and 30 per cent. for area reduction.

Jan 1, 1928

Jan 1, 1963

By G. Belardi

This paper presents the preliminary results of a research programme conducted to assess the feasibility of a flotation technique in the remediation of soils severely affected by heavy metal contamination. The use of flotation in soil remediation is a recent practice. The main difficulties are given by the variety and peculiarity of the heavy metal containing species, and also by the grain size. Most of the studies reported in the literature concern the use of conventional collectors, such as xanthates, after a preliminary chemical modification of the metal bearing species through sulphidization. On the basis of the minera-petrographic characterization and of speciation, some classes of reagents have been selected, capable of acting both on metal-bearing species and all metallic cations to be separated. The design of the synthetic molecules has been based on the coordinative properties of the metallic centres and functionalized in order to act as collectors for a wide range of metals independently on their surrounding atoms. In laboratory experiments a sample of stream sediment has been utilized, whose contamination is caused by the runoff from Sardinia mine waste dumps and overflow from the settling ponds. The material showed contamination mainly from Zn, Pb and Cu and to a lesser extent from Cr, Ni, Cd, and Sb associated in mixed particles of Fe and Mn. Flotation tests on a laboratory scale have been performed on grain sizes less than 355 µm in laboratory cell Minerais & Metaux. The effects of the structure of collectors (functional group, chain configuration) as well as of the principal flotation parameters (such as pH, concentration of reagent) on the grade and recovery of heavy metals in the concentrate and in the tailings (remediated soil) have been investigated. The results of the laboratory tests substantially confirm the theoretical premises, and the most effecive reagents found belong to the classes ATP, MBT, MBO, fat acids and phosphates.

Jan 1, 2014

By Mark S. Stagg, David E. Siskind, Stephen V. Crun, Willard E. Pierce

The USBM is studying the impacts of low-frequency blast vibrations on residences to assess both response and cracking potential. Complementing coal mining sites monitored in the midwest and east, vibrations were analyzed at a major construction site in southern Florida where potentially serious low-frequency blast vibrations were believed to exist.

Jan 1, 1996

El uso del motor diesel en distintos asientos mineros permite el funcionamiento de los generadores eléctricos, compresoras portátiles y viejas máquinas diesel. Por tal motivo, el presente trabajo, describe su importancia como fuente de energía minera y los criterios de selección del grupo diesel eléctrico. La aplicación de la energía eléctrica en las minas se da través del uso de máquinas, cuya fuente energética permite diversos tipos de generación como la hidraúlica, térmica y atómica, formando parte de los uno de los criterios selectivos entre otras fuentes de generación. A este criterio se suma que el objetivo del generador es transformar la energía eléctrica en mecánica, para ser transmitida y distribuida posteriormente. Respecto del costo de mantenimiento, el uso del motor diesel supone una inversión baja ya que excluye la posibilidad de canales, túneles y líneas de transmisión, aunque el costo de la máquinas aumenta cuando es para operación en altura. Pese a esta limitación, la predilección por el uso del motor diesel responde a una rapidez en el montaje, la facilidad para el arranque y detenimiento, y a la dimensión del espacio.

Jul 20, 1959

By Charles G. Howard

Accidents involving underground rail transport were analyzed to quantify the magnitude and the operational requirements for individual mine car braking systems. The results showed that the brake preventable accidents represent only 2% of the total underground fatal accidents and less than 1% of the total underground nonfatal accidents. In addition, the brake preventable accidents are expected to decline over the next decade. The costs of accidents involving deaths and Injuries were determined using various well accepted methods. The costs of a brake retrofit program for all operating underground coal cars were developed separately for small and large coal mines. Costs of retrofit brakes, new car brakes, maintenance, inspection and repair facilities were included in the esimates. The analysis showed that a retrofit program would not significantly increase safety, and that the program cost would greatly exceed the corresponding expected benefits.

Jan 1, 1979

By Gary L. Simmons

Noranda&apos;s Grey Eagle Mine and Mill, located in the Siskiyou Mountains of Northern California, began shakedown operations in the late fall and early winter of 1982. This paper describes some of the unique features in mining, milling and water treatment operation at Grey Eagle. In addition, major start-up problems in the mill and water treatment plant are discussed along with measures taken to correct these problems.

Jan 1, 1984

By A. J. Barry

A method was developed for testing the anchorages obtained with 3/4-inch, expansion-type, headed bolt and shell assemblies. The apparatus is a modification of that used in testing -inch-diameter, slotted-type bolts. Four makes of expansion-type shells were used in 64 tests made in sandstone and shale roof. The results show that for 3 makes of shells the anchorage effectiveness is independent of the installed land, and for the fourth make of shell a better anchorage is obtained when instilled at a load of 8,000 pounds. The results also show that deformation of the expansion plug influences the majority of the anchorages obtained with two makes of shells. This deformation causes a larger increase in displacement for a given added increment of load. The data from 48 of the 64 tests were combined to establish a relationship between average displacement and increase in bolt load (above the installed load). This relationship can be used to evaluate the anchorage effectiveness of any 3/4-inch-diameter, expansion-type, headed bolt and shell assembly tested in the field.

Jan 1, 1956

By G Lane, S La Brooy

A century ago, new mines were often accompanied by smelters. In Australia, smelters were built at the Daydream mine near Broken Hill, at Kuridala and Mount Elliott near Mount Isa, Broken Hill, Mount Lyell, Mount Morgan, Mount Isa, and more recently at Tennant Creek, Kalgoorlie and Olympic Dam. Now the big miners eschew site-based processing in favour of shipping concentrate to smelters in Europe and Asia. As Chip Goodyear was in the process of vacating his leadership role at BHP Billiton, he was quoted as saying that BHP should concentrate on mining ore and leave æto others the skill set of processing that materialÆ. Yet there are times when on-site processing clearly makes sense. Few companies ship gold ore or concentrate to China for gold extraction. New smelters are being built in Zambia. Solvent-extraction and electrowinning plants frequently produce copper from oxide ores and concentrates while pressure leaching is increasingly being considered for copper sulfide ores. Some argue that on-site processing is best because the waste products can be returned to the ground from whence they came, avoiding potentially large disposal costs in more-populated areas. Copper treatment and refining charges will not remain at $45 per tonne and 4.5 cents per pound forever. This paper examines when it makes sense to use on-site pyro- or hydrometallurgical processes in todayÆs environment and comments on how current trends might alter the balance in future.

Jan 1, 2008