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By D. S. Burgess

This report summarizes the incidents that preceded the December 9, 1970, propane-air explosion in Port Hudson, Mo., and then attempts to establish the nature of the explosion from the ensuing events. Special emphasis is given to possible ignition sources, the distribution of flammable vapors, and the analysis of blast damage. Both near-and far-field damage indicated that this explosion may be attributed to the detonation of propane in air with an energy release equivalent to that from about 50 tons of detonating TNT.

Jan 1, 1973

By H. C. H. Darley

The principal causes of unstable boreholes* have been known for many years. For example, in a paper published in 1938, Halbouty and Kaldenbachl listed nearly all the classes of troublesome shales that we know today. Much progress has been made since then, but we still have difficulty in identifying the cause of hole problems and consequently in selecting the right technique for combatting them. This subject was discussed at length by Kelly2 in a recent paper and much valuable information was provided. In the Shell Laboratory it was felt that there was a need for a better understanding of the basic mechanisms underlying the various forms of hole instability, and accordingly, a study was undertaken. This entailed reviewing the physics and chemistry of shales, developing tests for characterizing shales, and constructing a model to study borehole stability. Full simulation of underground conditions was not attempted; for example, we used reconstituted shale specimens, and often simple solutions or suspensions rather than practical drilling muds. Such procedures are necessary in order to establish mechanisms, but caution must be exercised in applying the results to the more complex conditions in the field. Part I — Compaction Swelling and Dispersion of Shales Compaction of Sediments Shales are formed by the compaction of sediments. Water is expressed as sediments are buried by subsequent layers, and the degree of compaction is proportional to the depth of burial, provided the water is able to escape easily to permeable formations. The younger sediments, when recovered at the surface, soften and disperse when mixed with water; the older shales have undergone diagenesis (alteration of the clay minerals, secondary cementation, etc.), and remain hard and unaffected by water. In this paper we shall apply the term "shale", as the drilling engineer does, to everything from clays, which are highly reactive to water, to completely lithified materials such as claystones and slates, which are completely inert. However, because these materials behave quite differently when encountered in the drilling well, it is desirable to develop a simple means of characterizing them. The feature that distinguishes the various shales is their dispersibility in water —soft clays disperse readily, harder shales disperse slowly when agitated, the lithified materials will not disperse at all unless milled. In the dispersibility test used in our study, a weighed amount of dry shale particles in the 12-to-100-mesh-size range was placed in a tube filled with distilled water and allowed to soak for 16 hours. The

Jan 1, 1970

By O. Matwijenko

"1. IntroductionThe Falconbridge Owl Creek open pit gold mine is located 17 km northeast of Timmins and 2.5 km west of the Kidd Creek metallurgical site. Diamond drilling first commenced in 1964 with open pit production commencing in 1982. Other operations within close proximity are the Canamax-Pamour Bell Creek Mine and the Falconbridge Hoyle Pond Mine.Since 1982, 1,216,000 tonnes assaying 4.5 g/t have been processed in six concentrators. This paper summarizes the metallurgy achieved with special emphasis on some of the unique problems encountered in the processing of this refractory ore.2. GeologyThe Owl Creek deposit, located 3 km north of the Porcupine-Destor fault is in easterly trending carbonaceously altered volcanic and sedimentary rocks. The deposit strikes east and dips steeply north.The ore body can be best described as a wedge shaped sandwich of volcanic basalt between the surrounding sedimentary greywacke. The north and south volcanic-sedimentary interfaces are marked by graphitic zones. The south graphitic contact is more continuous with its thickness varying from 5 m to 20 m as compared to 0.5 m to 3 m to the north. Quartz veins occur throughout the deposit with a predominant vein running along the south contact where it is characterized by numerous graphitic inclusions. Some veins carrying gold values intrude into the sediments in the north. With depth the sedimentary and volcanic zones taper while the quartz-graphitic zones appear to become more dominant."

Jan 1, 1988

By C. F. McCarroll

The effectiveness of an industry?s safety activities can be gaged best by the accident records of that industry. In an effort to gage conditions in the petroleum industry, and with the objective of helping to reduce the number of accidents in it, the Bureau of Mines from time to time has tabulated, analyzed, and published pertinent statistical information3/. These reports have dealt with distribution, causes, and costs and related phases of accidents for various and collective divisions of the petroleum industry in several sections of the country. This type of study aids the personnel of the Bureau in planning the course of its activities in accident-prevention work and gives useful data to persons engaged or interested in the promotion of safety in the petroleum industry, which will aid them in their efforts to reduce the number and severity of accidents. A majority of petroleum operators and ?service" contractors have acknowledged their responsibility to provide their employees with safe working conditions and to their stockholders for greater economic value of invested capital by establishing safety divisions within their respective organizations. Such divisions have a primary duty, namely, to see that properly designed and guarded machinery and working equipment are furnished the employees and that they are trained in the safest practical methods of performing their work. Some companies and individual operators, however, have shown little or

Jan 1, 1939

By R. L. F. Kay, T. A. Fletcher, A. J. Boyce, C. M. Rice

Paper presented at Mineralisation in the Caledonides, the Mike Gallagher memorial meeting held in Edinburgh, 27-28 June 1996. The synorogenic, mafic Ordovician intrusion comprises orthopyroxene-rich xenoliths and mafic-ultramafic cumulates with low-grade pyrrhotite, chalcopyrite and pentlandite mineralisation. Despite abundant textural, mineralogical and O isotope evidence for significant assimilation of country rocks, S isotopes indicate only a modest uptake and suggest that mineralisation is dominated by magmatic sulphur. The preferred explanantion is that the magma was close to S saturation on emplacement. Uptake of elements such as Si and O led to early crystallisation of orthopyroxene, resorption of olivine and early segregation of a sulphide liquid. Post-magmatic interaction with a high-temperature, surface-derived fluid, whose movement may have been controlled by regional shear zones, reset biotite and whole-rock O isotope values but not those of orthopyroxene. This model identifies the presence of olivine-rich rocks and evidence of extensive assimilation as guides to prospectivity

Jun 19, 1905

By Harris J. W

The treatment plant at The Great Boulder Proprietary Gold Mines Limited was designed and erected by Chas. Ruwolt Proprietary Limited in 1934 to mill 12,000 short tons per month. The flow sheet called for fine grinding, straking, flotation, roasting of the flotation concentrates and cyanidation of the resulting calcine.In 1937 considerable alterations and additions were made to the plant. The grindin,g section was duplicated with addition of two 8 ft. x 6 ft. Abco Ball Mills to increase the throughput to 28,000 tons per month, and the flow sheet was changed from "straight flotation" to "precyanidation and flotation" neeessitating the addition of thickeners, agitators, Oliver filters and Edwards roasters.A further change to the flow sheet was made in 1942 with the introduction of sulphur dioxide conditioning ahead of the flotation section, to permit the treatment of 500,000 tons of oxidised ore. Since that date no major alterations were made to the flow sheet or equipment until 1950, when the modifications set out in this paper were commenced with the object of reducing costs and increasing plant efficiency.These modifications are dealt with under the section headings and are therefore not necessarily in chronological order.CRUSHING SECTIONThere has been no material alteration in this section although at the time of writing a 650 ton capacity ore bin is being erected ahead of the primary Jaques crusher. This bin will reduc'e the crushing time from a three shift to a two shift basis and reduce the labour force required by two men, giving an annual saving of £2,000.FINE GRINDING SECTIONAlterations to the grinding section were commenced in 1950. Prior to this date the grinding flow sheet calle...

Jan 1, 1955

By Thainá Silveira Garcia Mendes

A manutenção de monumentos e obras históricas deve ser executada com o uso de argamassa de cal, devido à sua maior permeabilidade e por preservar as características originais da obra. Entretanto, o uso de revestimento de tinta acrílica comercial sobre esta argamassa interfere na permeabilidade da construção como um todo, por vedar a superfície das paredes e tetos, internos e externos. Como uma alternativa que permite maior permeabilidade, tem-se a tinta à base de solo, constituída de água, cola branca e solo rico em silte e argila. O presente trabalho tem como objetivo quantificar e comparar as permeabilidades de amostras de argamassa de cal revestidas com tinta acrílica e com tinta de solo. Usou-se o método do tubo de Karsten para medir a permeabilidade dos dois revestimentos em comparação com a argamassa de cal sem revestimento. Os resultados dos ensaios indicaram que o revestimento de tinta à base de solo apresenta permeabilidade significativamente maior que a acrílica, sendo então mais indicada para o uso em restauro e manutenção de edificações históricas.

Oct 30, 2017

By E. A. Metz

Ergonomics is the art and science that tries to understand the complex interrelationships among employees, their work environment, equipment, work methods and job demands. Coal and metal/nonmetal miners are exposed to a higher number of ergonomic risk factors than in non-mining occupations. In addition, studies have shown that these miners experience more degenerative disc disease and osteoarthritis than comparable industrial populations. A general discussion of the risk factors that cause overexertion injuries and disorders will be presented. In addition, the basic principles of ergonomics will be discussed with specific cases to show how successful programs have been developed. A successful ergonomics program should simultaneously improve health and enhance productivity.

Jan 1, 2002

By Jovanir Francisqueto

O objetivo deste projeto foi elevar a produtividade do pátio de placas do Laminador de Tiras a Quente da ArcelorMittal Tubarão através da alteração do processo de sequenciamento do Laminador de Tiras a Quente com a criação do processo de realocação de placas após a formação da chance de laminação. O trabalho iniciouse com a definição de regras metalúrgicas de realocação de materiais e definição dos critérios operacionais e de atendimento a pedidos para posteriormente ser desenvolvido o software de otimização para a execução da realocação automática de placas na chance de laminação com foco na redução de movimentações no pátio do Laminador de Tiras a Quente. Com a implantação do processo/sistema espera-se conseguir uma redução de aproximadamente 60% nas movimentações de placas para formação da chance de laminação, conforme demonstrado nas simulações com dados reais e consequentemente reduzindo número de paradas de forno em função de problemas de produtividade do pátio de placas visando o aumento da produção do Laminador de Tiras a Quente em torno de 15 Kt/ano.

Aug 16, 2017

By M. M. Tilman

In a Bureau of Mines investigation to develop lead alloys with improved tensile strength and creep resistance, lead-base alloys containing cadmium and antimony in nominal 1-to-1 atomic ratios were melted in air, cast, and rolled into sheet to 90 percent reduction at temperatures varying from room temperature to 175° C. Tensile testing at room temperature and stress-rupture testing at 900±3° F were conducted on the as-rolled alloys. The best tensile properties were observed in an alloy of Pb-4.2 wt pct Cd-4.5 wt pct Sb which exhibited an average tensile strength of 7,270 psi with 36 percent elongation in 2 inches. An alloy of Pb-5.5 wt pct Cd-6.0 wt pct Sb had 100-hour stress-rupture values of approximately 2,100 psi and 1,000-hour values of approximately 1,700 psi.

Jan 1, 1969

By Robert Hopler

That some time in the year 1872 there was organized an association composed of practically all of the manufacturers of gunpowder and other high explosives in the United States, the members of which said association were as follows: E. I. du Pont de Nemours & Co., The Hazard Powder Company, Laflin & Rand Powder Company, Oriental Powder Mills, American Powder Company, The Miami Powder Company, and Austin Powder Company of Cleveland, all of which or their successors are defendants herein; that the object and purpose of said association was the elimination of all competition between the members thereof in the shipment and sale of gunpowder and other high explosives among the various States and Territories of the United States; that the only manufacturers of gunpowder and other high explosives which did not join such association at the time of its organization were the California Powder Works, The Sycamore Manufacturing Company, and The Lake Superior Powder Company, but your petitioner alleges that each of said three last named companies

Jan 1, 2008

By James M. Spear

The U.S. Bureau of Mines and the U.S. Geological Survey conducted a mineral survey of the Elk Creek RARE II area during the summer of 1981. The study area encompasses 18,900 acres [29.5 sq mi (7,680 ha)] along Elk Creek, 18 mi (30 km) southeast of Covello, California. No mineral resources were identified by the U.S. Bureau of Mines during this survey. Assay results of samples taken in this area indicate only trace amounts of manganese and chromium. No radioactive or fluorescent minerals were detected. No oil and gas, coal, or geothermal leases have been recorded for the study area.

Jan 1, 1982

By Keith S. Olson

During 1982 and 1983, the Bureau of Mines concentrated its fugitive dust control research on haulage road dust suppression by newer chemi-cals relatively unknown in the mineral industry, innovative dust control designs for haulage trucks, chemical tailing basin stabilization, and combined chemical and vegetation tailing basin stabilization. Relatively unknown dust suppression chemicals and innovative aerodynamic modifications to haulage truck fender designs were tested on a Minnesota sand and gravel operation haulage road. Magnesium chloride salt at 95-pct control efficiency and a petroleum derivative at 70-pct control efficiency were effective in suppressing dust generated by haulage vehicles; however, none of the fender modifications were successful. Commonly used dust suppressant chemicals were tested on a Minnesota taconite tailing basin to reduce the dust lift-off during the spring and fall dry seasons. The most successful chemical was lignin sulfonate with a seasonal cost of less than $200 per acre to achieve 90-pct dust control. When chemical treatments for immediate dust control were com-bined with revegetation for permanent control, the most promising chemical treatment based on vegetation response was lime-neutralized lignin sulfonate.

Jan 1, 1987

By N. S. Shan

This report presents the results of a study to determine compaction criteria for coal waste embankments. The purpose of this study is to evaluate the costs and resulting effects on the engineering proper-ties of coal waste materials, utilizing different compaction methods, equipment passes, and lift thickness. Based on the results of the study, a cost efficient compaction method that will attain the desired results will be recommended to the coal mining industry. The report describes a comprehensive literature search into the compaction of coal waste materials, field compaction programs, laboratory investigations, analysis of test data as well as conclusions and recommendations for establishing the compaction criteria. The findings obtained in this investigation are intended to supply much needed information and to justify the guidelines that have been recommended.

Jan 1, 1981

By Rodrigo Prestes Limberger

A investigação do comportamento de um mandril com diferentes diâmetros ao longo de seu comprimento no forjamento incremental em matriz aberta de eixos vazados para aerogeradores é estudada. Tem-se por finalidade a fabricação de um mandril que se adeque à peça forjada e atinja o formato proposto. Através do uso de simulações numéricas computacionais com o software Simufact.forming 12, e simulações com o material modelo plasticina, possíveis geometrias de mandris foram estudadas, variando a angulação na região de troca de diâmetros ao longo do comprimento. Foram estudados ângulos de 0º, 30º e 60º, analisando o comportamento da fluência do material na região.

Aug 16, 2017

By G. Simard, M. J. Gagnon, A. Charette, G. Péloquin

"In the Bayer process, flocculants are introduced in the feed well to enhance the aggregation of red mud particles. To gain a better understanding of the flocculation process taking place in the feed well, shearinduced flocculation was achieved using concentric rotating cylinders (Couette system). Our previous work has shown the effect of the shear rate on the aggregate’s settling rate and on residual turbidity of the Bayer liquor. In this study, the data demonstrated that the aggregates at selected shear levels appear as a population with a widespread size distribution. By using an imagery apparatus, it was possible to measure the size, the shape, and the sedimentation velocity of the larger red mud aggregates. Marked differences were noticed in the characteristics of the aggregate populations obtained under various shear conditions. IntroductionIn the Bayer process, red mud particles are separated from the liquor in primary clarifiers and washing circuits under the action of synthetic polymers. The agitation in the feed pipe and in the feed well affects the flocculation since the aggregates are formed by the interaction between the red mud particles and the polymers. A minimum shear rate is needed to initiate the aggregation process of fine particles (Warren, 1975).Different systems have been used to study the effects of shear on the flocculation process (Tampo and Watanabe, 1979; Klimpel and Hogg, 1986; Scott et al., 1996; Biggs and Lant, 2000). The Couette flow system has been used in some studies on shear-flocculation (Oles, 1992; Farrow and Swift, 1996a, 1996b). The importance of the physical properties of the aggregates in determining the efficiency of the solid-liquid separation process within a given gravity thickener has been demonstrated (Farrow and Warren, 1989a)"

Jan 1, 2002

Results of laboratory studies on the flotation of marmatite (zinc sulphide) with new reagents, which were developed to avoid the use of copper sulphate, are presented.Episulphides were chosen as the basis for the reagents because of their reported special chemical affinity for zinc and cadmium. Attempts were made to solubilize and introduce functional groups to episulphides with organic and inorganic acids, ammonia, phenol, aniline, diethylamine, and pyridine. As a class of reagents, the episulphide-amine combination was generally found effective in zinc sulphide flotation to a greater or lesser degree. Best results were obtained with ethylene sulphide-aniline combination. Although anilino-ethyl mercaptan is the reported reaction product of aniline and ethylene sulphide, it was concluded that the effective zinc sulphide flotation with ethylene sulphide-aniline combination is not entirely due to the formation of the mercaptan.The economics of the possible usage of ethylene sulphide-aniline reagent are discussed.

Jan 1, 1974

By Loren R. Anderson

A probabilistic slope stability computer model was developed at Utah State University and independently evaluated by CH2M Hill Consulting Engineers as a design and analysis tool. Volume I of this report describes the model and Volumes III and IV are users manuals for the computer programs. This volume (Volume II) constitutes the report by the CH2M Hill. It includes a description of a field investigation and stability analysis of an existing tailings dam. Based on the results of the analysis, the tailings dam was evaluated for redesign using probabilistic considerations. Conclusions are made regarding the usefulness of the model as a design tool.

Jan 1, 1982

By Olliver J. G

Over 400,000 tonnes of kaolin, sillimanite, mica, kyanite, feldspar and rutile have been mined from the unique Williamstown orebodies since their discovery in the early 1900's. Numerous companies; both large and small were associated with the early development of these deposits but since the formation of Australian Industrial Minerals in 1947, this company has been the only significant producer. A combination of mining and management problems almost forced closure of the mine in the late 1970's but this was averted by a changed attitude towards mine planning. Mine development is now based on detailed geological and technical investigations, exploration for additional ore reserves is being conducted and laboratory and pilot scale studies are being undertaken to utilise both low grade ores and waste materials. The professional approach to mine and market development will ensure that Williamstown mineral products will continue to be available for many years.

Jan 1, 1989

By W. Greuer

The objective of this paper is to demonstrate how site-specific slope stability analysis can be performed entirely from the desktop with satellite images, Geographic Information Systems (GIS), and slope stability software packages. This type of analysis would effectively eliminate or restrict the need for expensive field testing of geotechnical properties of a hillside, pit wall, berm, or embankment, and would be particularly useful for slope failure mitigation at remote or otherwise inaccessible locations.

Jul 17, 2000