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By Robert W. Waytulonis

Mining regulations pertaining to the use of diesel engines were solicited from foreign countries with mining operations by the Bureau of Mines. Responses were received from 27 countries; the information received and U.S. regulations were reviewed, and those parts pertaining to the use of diesel engines in underground mining were synopsized according to the following subject categories: types of engines permitted, testing and certification procedures, fuel quality specifications, emission control requirements, procedures and frequency of testing exhaust gases, mine air quality and quantity (ventilation) requirements, procedures for testing mine air quality and quantity, and noise standards. All categories except the types of engines permitted and testing and certification procedures are summarized in tables. Contacts are provided for each country to facilitate inquiries concerning regulation revisions or interpretation.

Jan 1, 1987

By H. Boghosian

This paper presents the design and construction of a deep basement in a steeply sloping site in glacial till in Glasgow city centre. Existing foundations, adjacent structures and services, in tandem with asymmetric loading, presented particular challenges in the planning, execution and design of the project. The construction methods and temporary works, analysis by the Finite Element method and monitoring carried out are all described.

Jan 1, 2006

By M. I. Brittan

Cyanide leaching of two West African gold ores was studied in multiple laboratories to provide process-engineering data for plant design purposes. Unusually slow leach extraction kinetics were observed using routine cyanide leach test procedures with pregnant solution monitoring. Carbon-in-leach testing, however, showed normal rapid kinetic behavior, with the same ultimate gold extractions being reached in much shorter elapsed times. Kinetic curves based on washed solids assays also exhibited more typical leaching characteristics. The results bore all the hallmarks of some equilibrium inhibition of the leaching. It was surmised that ore gangue components were responsible for weakly adsorbing gold-cyanide complex reaction product, thereby holding up soluble gold in the solid phase. The term ?preg-borrowing? was coined to describe the reversible phenomenon and distinguish it from irreversible preg-robbing. The two ores investigated may represent an extreme form of a more general effect that in most instances might pass unnoticed. The effect can lead to misinterpretation of kinetic leach curve data and underestimation of calculated ore head grades.

Jan 1, 2008

By Joseph A. Corgan

The river- or dredge-coal industry of Pennsylvania is conducted on many of the rivers and creeks that drain the Pennsylvania anthracite fields. Coal thus recovered found its way into the streams as coal was being prepared for market by the anthracite industry proper, in the northeastern part of the State. The Principal rivers draining; the fields, those where dredging is taking place, are the Susquehanna, Schuylkill, and Lehigh. Several creeks - the Shamokin, Mahanoy, Wiconisco, and Swatara - also are productive sources of river or creek coal. Operations along the streams cover a wide territory, and along the Susquchanna alone; dredges are recovering coal for about 160 miles. Anthracite was a significant factor in the early industrial development of the United States. Industry used it to generate steam, and railroads used it as fuel for locomotives; but it probably was most important industrially in the smelting of iron ore. For more than a hundred years homes have been heated with this fuel. From the beginning of mining in 1807, to 1940, more than 4 billion net tons of anthracite had been prepared and shipped to market. In the preparation process much of the smaller-size coal and refuse found their way into rivers and creeks which carried the material many miles. This study is concerned with the recovery of that anthracite from those rivers and creeks.

Jan 1, 1942

By Sri Sawmliana, P. Pal Roy

Blasting Gallery (BG) method was introduced in India for higher production and low cost of excavation to substitute conventional hand section and stowing methods for thick coal seam. The Singareni Collieries Company Ltd. (SCCL) adopted this method in the year 1989 and since then successfully operating at GDK-10, GDK-8 & VK-7 Incline mines in Andra Pradesh, a southern state of India. It is also successful at Chora 10 Pit Colliery of Eastern Coalfields Ltd. (ECL) in West Bengal whereas at East Katras Colliery of Bharat Coking Coal Ltd. (BCCL) in Jharkhand State, the method has been partially successful due to some geological constraints of the area.

Jan 1, 2003

By Shawn Orser, Jennifer Waddell, Mike Sierakowski, Tom Barrett

Production evaluations were conducted at Daisy Gold Mine (Glamis Gold, formerly Rayrock), between August, 1997 and August, 1998 to quantify the effect of 3M fluorochemical surfactants (fluorosurfactants) on extraction kinetics and gold recovery in gold heap leach mining operations. Ore was treated at a level of 7-10 grams surfactant per ton of ore using 3M Pluorad TM Leach Mining Additive PC-GOLD. Kinetics and gold recovery were determined by solution assay for each of the tests. Both tests indicated improved kinetics, and data from Test 2 was used for determination of a quantitative increase in gold recovery resulting from PC-GOLD addition. A discussion of test results including methods used to determine gold recovery is provided.

Jan 1, 2000

By Arthur Notmon

WORLD production of the three major nonferrous metals, copper, lead, and zinc, in 1939 will aggregate about 6,050;000 tons, compared with the all-time peak of 6,237,944 tons in 1937, and the previous peak of 5,679,442 tons in 1929. The United States will furnish 30.9 per cent of the total compared with 30.4 per cent in 1937 and 41.3 per cent in 1929. Table 1 gives the details of the three metals.

Jan 1, 1940

By Luis Romero, Edilberto Linares, Steve Windle

El yacimiento de Zafranal —proyecto de pórfidos de cobre y oro ubicado en la región Arequipa, Perú— en sí mismo ha penetrado en lo que parece ser un salto dextral sobre una estructura del SFIC. A nivel de yacimiento, se ha mapeado una serie de fallas pronunciadas WNW en la zona mineralizada principal, consistentes con la transtensión dextral inferida. Esta estructura de fallas se trazó en 3-D a partir de las zonas de gubias identificadas en la fotografía de testigos, método que permitió elaborar un modelo estructural de forma rápida y con consistencia interna. La cinemática de las vetas y los patrones de afloramiento trazados generalmente coinciden con las estructuras interpretadas. El movimiento dextral inferido en el SFIC en el Cretácico Superior es consistente con un vector de convergencia de placas hacia el norte, y puede ser utilizado para identificar targets estructurales para sistemas de edad similar, tanto en el piamonte como en la cordillera.

Dec 31, 2019

By Louis Moyd

In the preparation of illustrations to accompany reports of investigations concerning particle shapes of various natural and manufactured materials proposed for use as fine aggretates in concrete structures, it was found that stereoscopic views of such materials presented the information much more effectively than the usual two-dimensional photographs. With the whole-hearted cooperation of the Photographic Section, a technique was developed in the petrographic laboratory of the Concrete Research Division, U.S. Corps of Engineers, at Clinton, Miss., for simple and rapid preparation of paired stereoscopic photographs and micrographs. The method requires only equipment which is usually part of the general stock of any laboratory, and it is adaptable for all purposes in which three-dimensional views would be found superior to ordinary photographs.

Jan 1, 1949

[ENGLISH active earth pressure adapter additive adhesion admixture, addition adsorbed water aggregate air air entrainment air hose allowable bearing value allowable pile bearing load]

Jan 1, 1994

By Warren H. Weisz

A cement, in the broad sense, is any substance which will cause various materials to adhere to each other. Clay was probably the first material to be used by man as a cement or binding agent. Water occurs in or is mixed with the clay to make it plastic, so that it can be formed in place. The sun and air remove the water from the clay and on drying strength is developed. The clays unless fired are not too resistant to water, therefore, their use is best when restricted to dry areas. Gypsum used as a cementitious material is not the subject of this paper, but its use dates back thousands of years. Gypsum mortars were used by the Egyptians in building such massive masonry structures as the pyramids. The Egyptian mortar consisted of a mixture of sand with burned gypsum (of an impure type of 81.5 per cent calcium sulphate and 9.5 per cent calcium carbonate) for the cementitious material. The burning of this type of cementitious material took place at relatively low temperature. These burning reactions will be covered later when the dehydration of gypsum is discussed. The setting of the partially dehydrated gypsum is considered to be crystallization from a supersaturated solution which deposits crystals of dihydrate (gypsum). In low water-content mixes, the interlocking of the needle-like crystals helps to produce higher strengths. Slaked lime made from limestone burned at higher temperatures (1648 F is generally considered as the calcining temperature, although under certain conditions incipient calcination will take place at 1250 F) is another early-period cementitious material. During slaking with water, a colloidal or amorphous hydrated lime is formed. When it is allowed to dry, it hardens and develops low strengths. On exposure to the carbon dioxide of air in the presence of some moisture, carbon dioxide is adsorbed and part of the calcium hydroxide is converted to calcium carbonate. Structures in which a lime mortar is used continue to grow in strength as this reaction proflesses. Hydrated lime has the disadvantage of not setting under water.

Jan 1, 1960

Application of microprocessors, programmable logic devices, and other computer-oriented hardware and software on-board large surface mining equipment to optimize availability and productivity, stretch machine life, and protect against catastrophic breakdown has been a goal of heavy-equipment manufacturers for several years. Progress in this direction has not been as rapid as many manufacturers anticipated in the mid-1980s, and, on the other side of the coin, mining industry and machine operator acceptance of such products has not always been enthusiastic. However, the trend toward such development seems undeniable. Large surface mining equipment in the future will doubtless carry more, and not fewer, applications of computers and computer-related products. The intensity of development interest and degree of progress in commercializing such on-board computer and computer-related products on surface mining equipment varies considerably among the manufacturers. Summarized here are the on-board computer-oriented products of three heavy-equipment suppliers-P&H Harnishfeger, Marathon LeTourneau, and Haulpak not a comprehensive survey, but, perhaps indicative of the direction such development is taking.

Jan 1, 1990

By Louis W. Cope

Many Americans have seen Greenland while flying over it on their way to or from Europe. Few have visited this largest island in the world. Portions of the 20 percent of the territory that are not ice-covered are highly mineralized. Greenland could become very productive if the present interest in exploration increases. The people and Greenland’s history The population of Greenland is 57,000. Twenty percent are Europeans, mainly of Danish decent, while 80percent are native Greenlandic or mixed Greenlandic-European. The native population is the same as the Inuit of the Canadian Arctic. They speak the same language.

Jan 1, 2004

By Shahé Shnorhokian

Remnant pillars evolve towards the latter stages of mining in an orebody and act as repositories of mining-induced stress. It is therefore crucial to plan ahead as to their dimensions and location with respect to the local geology. A case study of a Canadian base metal mine was examined for the planned mining sequence scenario to identify the stress regimes acting on a future remnant pillar occurring between levels 4800 and 5100, near a brittle dyke. A mine-wide model was constructed in FLAC3D and input parameters included results from field measurements of the direction and magnitude of the principal stresses, and the geomechanical properties of the different formations. Prior to the study, the model was calibrated based on a 6-year record of mining-induced seismicity and rockburst events, focusing on large event clusters. The mining sequence followed at the mine was then used in the model to study the planned future extraction program around the remnant pillar. It is shown that the distance of the remnant pillar from the dyke and another orebody plays an influential role on the stress levels developed in the pillar.

Jun 1, 2012

By R. S. Handy

This paper describing the milling practices at tae concentrators of the Bunker Hill and Sullivan Mining and Concentrating Co. is one of a series being prepared by the United States Bureau of Mines on milling methods and costs in the United States. The possibility of useful comparisons has prompted the description of all five of the mills operated by the Bunker Hill and Sullivan Company in northern Idaho. The general features of these mills are tabulated below: [ ]

Jan 1, 1930

By Walter Nuñez

La finalización de la estimación de reservas de un modelo de mina cuestiona la asertividad del modelo de Mina para la planeación minera. En ese sentido, el presente texto señala la Reconciliación como la comparación real histórica de tonelaje, leyes y contenido fino estimado, entre el modelo de mina y planta concentradora. La reconciliación permite conocer y ajustar mediante el uso de factores, la planeación mensual y anual de los siguientes años de la operación minera, y así cumplir con los compromisos mensuales asumidos de envío de contenido fino desde mina. Así también se muestra el proceso que sigue la explotación minera a tajo abierto en Toquepala, las variables que influyen en la variación de la reconciliación y algunas pautas a considerar para minimizar estos errores de reconciliación entre mina y concentradora.

Sep 19, 2006

By E. D. Gardner

This bulletin, which discusses open-cut mining at the metal mines of the United States, is the last of a series of such papers by the Bureau of Mines describing the principal methods of mining.4 Open-cut mining is applicable to flat-lying mineral deposits relatively near the surface. Vein deposits seldom are amenable to this method, although outcrops of veins sometimes are worked as open pits. Most of the iron ore of the country is mined from open pits; according to the Minerals Yearbook, 67.4 percent was mined from open pits and 32.6 percent from underground mines in 1937. Open-cut mining is relatively new in the copper industry but yields more copper than any other method; in 1937 about 52 percent of the copper ore mined in the United States was taken from open pits. Lead-zinc ore has been produced from open pits in the Joplin (Mo.) district, but most of the deposits in this area, although flat-lying, are too deep to be mined economically by the open-cut method. In 1937 one company at Oronogo, Mo., was stripping overburden and mining mixed oxidized and sulfide ores by this method.

Jan 1, 1941

By C. A. Young

In-situ Fourier transform infrared/internal reflection spectroscopy (FT ?IR/IRS) has been extended to study oleate adsorption at a calcite surface. The birefringent and transmission limitations of calcite were overcome by using an appropriately designed optical setup and a near-infrared (NIR) spectrometer. An adsorption isotherm was determined at pH 9.2 and room temperature. Comparison with the fluorite/oleate adsorption isotherm determined by the same technique indicates that oleate abstraction by calcite can be as much as one order of magnitude larger than that by fluorite. Nevertheless, the hydrophobicity of the fluorite/oleate surface is greater for equivalent adsorption densities as indicated by contact angle measurements and flotation results. The monolayer region has been confirmed to be chemisorbed oleate at both calcite and fluorite surfaces. Furthermore, multichannel laser Raman spectroscopy (MLRS) showed that chemisorbed oleate at the fluorite surface undergoes a double-bond reaction with oxygen to form an epoxide/polyether complex. Such a reaction, however, could not be detected at the calcite surface. These phenomena are discussed in terms of the intrinsic surface properties of the mineral systems as well as the adsorption density and the cross-linking/polymerization reaction of the adsorbed oleate film.

Jan 1, 1993

By Dennis J. Callaghan

This report is the result of information obtained from a review of related literature, personal inquiry and on-site examination of active surface coal mining operations. Four improved surface coal mine systems are described in detail and evaluated for feasibility, implementation requirements, environmental benefit and costs. Engineering feasibility emphasizes equipment availability, compliance to design requirements, practicality and industry rating. Implementation potential emphasizes immediacy, ease, acceptability and constraints. Special attention was given to environmental responsiveness, both with regard to the solutions to mined-land reclamation problems and to the concurrency of reclamation. Each system description includes a hypothetical model mine with a depreciation schedule, capital summary, estimated annual production costs, sales price computation, production and operating cost summary, and a sensitivity analysis of mine price to stripping ratio. A program plan and time schedule for demonstrating a selected mining system covers site selection criteria, mine data collection, criteria for controlling and budgeting costs and reporting findings. Ten additional mining methods and techniques are briefly described and evaluated. Common reclamation problems are listed and described. Sixteen state reclamation laws and regulations are abstracted. Sixty-nine references are listed in the bibliography.

Jan 1, 1976

By S. C. Borah

Graphite, a mineral form of pure carbon, is one of the most versatile minerals in industry, because of its varying physical properties and characteristics. The mineral occurs naturally in the form of tubular crystals or microcrystalline earthy lumps, or it is disseminated in rocks, which have undergone intense metamorphism. India has a large deposition of graphite minerals out of which about 43% are found in Arunachal Pradesh. However, compared to the rest of the country, the North-East Region and particularly Arunachal Pradesh has not attracted attention till date for detail investigation for characterization, beneficiation, prospecting and/or exploitation of the mineral resources including graphite. Bulk graphite sample were collected from upper Subanshiri district of Arunachal Pradesh. Chemical analysis of the representative samples were carried out and found that 7.29%, 19.60% and 6.07% of fixed carbon (FC) is present in graphite sample collected from La-Lamdak, Bopi and Taliha, Arunachal Pradesh, respectively. Chemical analysis of the ash of the graphite sample shows presence of impurities such as silica, Al2O3, Fe2O3, Ca, Mg etc in the graphite sample which are also supported by XRD and SEM-EDX investigation. The graphite samples of Arunachal Pradesh are low grade and do not fulfill the market requirement for the industrial applications. Therefore, low-grade graphite is subjected to beneficiation for the upgradation of the graphite for industrial applications. We have adopted the dispersion?cum-settling technique for the beneficiation of the graphite sample collected from Arunachal Pradesh. The FC of 40.21% with 41.17% raw graphite recovery which is equivalent to 71.02% carbon recovery have been obtained by gravity separation technique using only distilled water without any chemical reagent in case of graphite sample collected from Bopi, Arunachal Pradesh. The graphite sample is upgraded up to 47.75% FC with 41.91% raw graphite recovery, which is equivalent to 85.85% carbon recovery with the pH adjustment at 9 with NaOH. Keywords: graphite, beneficiation, gravity separation, arunachal Pradesh

Sep 1, 2012