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By Jorge A. S. Tenorio, Chuanwei Zhuo, Joner O. Alves, Yiannis A. Levendis

"The disposal of wastes is a serious environmental problem, since available landfill space is dwindling. Their treatment by pyrolysis or combustion has merit, and the corresponding fuel or power production is of technological interest. However, such processes need a rigid control of emissions. This work addresses the gaseous light hydrocarbons (LHCs) generated during sequential pyrolysis and partial oxidation of unserviceable tires, PET bottles, com wastes (DDGS) and sugarcane bagasse in a two-stage laminar-flow horizontal furnace, kept at 1000 °C. Gas chromatography was used to identify and quantify the components of the emitted gaseous light hydrocarbons. The results showed that the biomass residues generated the highest emissions of aliphatic hydrocarbons, whereas PET generated the most aromatic hydrocarbons. When stainless steel meshes were inserted in the exhaust flow, it was found that hydrocarbon emissions were curtailed; as such meshes catalyzed partial conversion of these carbon-bearing gases to carbonaceous nanomaterials.IntroductionLight hydrocarbons (LHCs) are volatile organic compounds, consisting of hydrogen and carbon with low molecular weight; the most common species are methane, ethane, propane, butane, etc. LHCs are valuable since they are a very important energy resource. However, uncontrolled release of light hydrocarbon gases to the atmosphere should be avoided [l, 2]. In this work, a development is presented for the evaluation of LHCs generated during the controlled pyrolysis/combustion of several wastes in a two-stage laminar-flow horizontal furnace. Samples of unserviceable tires, post-consumer PET bottles and waste residues from the bioethanol industry (DDGS and sugarcane bagasse) were burned. A catalyst system, consisting of stainless steel screens, was tested for its effects on the gaseous emissions."

Jan 1, 2011

By Sidney Katell

This report is the fourth in the series, Bibliography of Investment and Operating Costs for Chemical and Petroleum Plants. The initial work, Bureau of Mines In- formation Circular 7516, was published in October 1949 in conjunction with the synthetic liquid fuels program authorized by Public Law 290, 78th Congress. It included references to and abstracts of publications appearing from 1930 to September 1948 on all processes in general use in the petroleum refining and chemical industries. A supplemental bibliography, Bureau of Mines Information Circular 7705, was published in January 1955 to cover the period September 1948 through June 1952; and Supplement 2, Information Circular 7751, published in September 1956, covered the period June 1952 through June 1954. The present supplement covers the period July 1954 through December 1956.21 The information in this paper was obtained from the following sources: 1. Bureau of Mines Information Circulars. 2. Bureau of Mines Reports of Investigations. 3. Chemical Engineering. 4. Chemical Engineering Progress. 5. Chemical Engineering Costs Quarterly (Cost Engineering).

Jan 1, 1958

Site specific geotechnical data, deposit characteristics and method of mining are key factors when assessing an appropriate slope design philosophy. Mining geotechnics should be viewed as an iterative design process linked closely with mine planning, development and operational safety constraints. This case study presents geotechnical investigations for slope design at Macraes Flat Gold Mine using kinematic, probabilistic and economic analyses tempered with knowledge of site specific conditions. The recommended designs not only reduce early waste stripping tonnages but also provide data to optimise final walls.

Jan 1, 1992

By K B. Bowley

This paper covers the application of a systematic maintenance plan by the Plant Engineering Department of Rio Algom Mines Limited, Milliken Division. The plan established the function of work study, developed and installed formal work planning and labour cost control procedures, and extended the existing preventive maintenance routines. In June, 1961, assisted by management consultants, a more scientific approach to maintenance was instituted. The emphasis was placed on the control of labour. The development and application of the primary control system was established with-in six months. Since then, the Department has operated for a year, consolidating the system. The procedure of the installation, the results achieved and the results to be expected will be discussed. JNTRODUCTION THE Milliken Division of Rio Algom Mines Limited operates a 3,000-ton-per-day uranium mine, in the Elliot Lake district of Ontario, which went into production in April of 1958. The lowest operating level is 3,000 feet below surface. Mining is carried out by open stopping, with planned pillar support and footwall haulage on rail.

Jan 1, 1963

G. SHERBURNE ROGERS,* Washington, D. C. (written discussion ?).- Mr. Neal's paper on the petroleum hydrology of the Mid-Continent district is a welcome contribution on a subject concerning which none too much is known; it is, I think, the first published description of the chemical character of the oil-field waters of the great Mid-Continent area. When studying the oil-field waters of the California fields several years ago, the differences in chemical composition between waters occurring at various horizons seemed to be sufficient to enable the operators to use water analyses as a basis for determining the source of the water flooding a well; and it is gratifying to find that, Mr. Neal has arrived at a similar conclusion. As Mr. Neal points out, the Mid-Continent waters are very different in character from those of the California fields, and casual. inspection

Jan 3, 1919

By Seetharama C. Deevi, Mohammad R. Hajaligol, Sarojini Deevi

"Carbides and nitrides of iron are being considered as magnetic materials for high-density recording due to their chemical stability and high-saturation magnetization values (> 100 emu/g). Iron carbides and iron nitrides with magnetic properties suitable for magnetic media were synthesized by employing a novel synthesis procedure based on fluidization of powders in reactive atmospheres. Fluidized-bed reactors of laboratory, bench, and pilot scale were employed for the synthesis of iron carbide, FeSC2, by reducing and carburizing U-Fe203 in the temperature range of 300 to 550 ºC. A temperature of 400· ºC and a reaction time of 2 to 3 h are found to be optimal for the synthesis of iron carbide. When the carburization was carried out in a reducing and carburizing atmosphere such as carbon monoxide, nucleation and growth of FeSC2 occurred directly from Fe304 with no intermediate phases such as FeO or Fe. Longer carburization times resulted in the deposition of carbon on the surfaces of FeSC2 particles due to Boudouard reaction, and higher temperatures favored the formation of a mixture of carbides such as FesC2 and Fe3C. Iron nitrides were synthesized by reducing u-Fe203 in the temperature range of 350 to 550 ºC, followed by nitriding in the temperature range of 350 to 550·ºC. The powders were characterized using X-ray diffraction, scanning electron microscopy, thermogravimetric analyzer, and a vibrating sample magnetometer.IntroductionRecent demand for high-quality recording of optical, electrical, and audio signals generated interest in magnetic tapes with high-recording densities as compared to the conventional magnetic tapes based on U-Fe203. At present, commercially available magnetic tapes contain maghematite, U-Fe203, as a magnetic material with a saturation magnetization of90 emu/g and a coercive force of 400 Oe. Recording of signals at a higher density per unit volume of magnetic material demands magnetic materials with high-saturation magnetization and a reasonable coercive force. Although metallic iron particles possess a saturation magnetization of 130 to 150 emu/g and a high coercive force of 1000 Oe, the gradual oxidation of iron-to-iron oxides (of lower saturation magnetization) prevents the use of iron particles for high-density recording. In contrast, iron carbides such as FesC2, Fe7C3 and iron nitrides such as Fe4N and Fe3N possess excellent magnetic properties coupled with good electrical conductivities and high hardness. The carbides and nitrides of iron have generated significant interest as magnetic materials for the next generation of magnetic tapes due to their unique magnetic properties and relatively greater oxidation resistance as compared to metallic iron particles [1-4]."

Jan 1, 1994

By M. J. Beus

A shaft is truly the "lifelinen of an underground mine. Damage to the shaft lining and guides as a result of ground movement can result in serious loss of production and extensive and continual repair. In some mining districts, annual shaft repair and maintenance costs resulting from high rock stresses and excessive displacement are in the millions of dollars per year. For many years, the Bureau of Mines has conducted research to characterize the rock mass and to develop structural guidelines to improve the design of accessways in deep mines. Much of this work has centered on determining the in situ conditions that affect the structural stability of shafts in the Coeur d'Alene Mining District of northern Idaho. Recent work by Beus and Board (1984) has concentrated on measuring the rock and support behavior during sinking of the Silver Shaft at the Lucky Friday Mine. These results are currently being used as a comparative data base for further basic research as well as to establish structural design criteria. The factors affecting the deign and structural stability of deep mine shafts are numerous. A design approach that use field data as input and directly compares field measurements with numerical models can validate the procedure and provide realistic design criteria. Naturally occurring "fixed? conditions such as magnitude, direction, and ratio of in situ stresses, geologic environment, and physical properties and constitutive relationships of the rock mass ere obviously basic to numerical modeling.

Jan 1, 1989

By Warren E. Morrison

A simplified energy model for the United States is quantified for a recent historical period. The basic model and calculated quantified structures are used for a number of analytical case studies that estimate midterm and long-range shifts in patterns of energy resources demand and required supply. Historical data series are presented for the years 1947 to 1965 in the form of integrated energy balances by source, form, and consuming sector. In case studies I to XII, conditional projections of historical trends of energy demand and required supply are made for the midterm period 1966 to 1980. The projections are carried out by correlation of major energy components with relevant independent variables such as major economic indicators. Simulations of the medium-range projections to 1980 are carried out by varying the assumptions for the determining variables to produce high-and low-range projections for the midterm period. Case studies XIII to XXII are long term contingency or technological forecasts to the year 2000. These cases assume technological changes or innovations that produce major shifts in the long term pattern of energy consumption and the mix of required resources. The domestic resource base is assessed in its ability to meet projected or forecast demand for energy resources under the midterm and longrun assumptions made in the various case studies. Various energy issues or problems identified from the analyses of the case studies are discussed, and possible alternative approaches to solutions to these issues or problems are suggested.

Jan 1, 1968

By Daniel T. Brian, O&apos

Exploration targets and results in the mining industry are commonly summarized in terms of tonnage and grade. Business appraisals require, as additional information, the expected profit or loss implied by the physical summay. The early incorporation of knowledge gained through financial analysis computations can provide a means for economically resolving many common exploration and development problems. Examples of such applications from the activities of exploration planning, reconnaissance, land acquisition, and development planning are presented. While prospecting for mineral deposits, geologists are frequently asked what they hope to find or have found. The response is usually descriptive, such as "50 million tons of 1% copper," and the economic implications are deferred until a capital investment decision is required. At that time, a financial analysis integrating the four analysis components is completed. These components are: 1) Tonnage and Average grade above cutoff grade 2) Capital and operating costs 3) Product value 4) Appropriate profit or loss accounting Close examination of these components reveals that there is no intrinsic reason for avoiding financial analyses at earlier stages in exploration, as long as the uncertainty of the estimate is realized. Tonnage and average grades are commonly estimated at early stages in exploration. For this component, the appropriate cutoff is the major uncertainty. Capital and operating costs are difficult to estimate before detailed quantitative information is available, but estimates useful for the types of applications pertinent to earlier exploration stages are possible. Product value estimates may or may not be difficult, depending on the pricing structure of the particular commodity. A simplified accounting procedure usually may be adopted without introducing any significant loss of validity. This paper describe some of the financial analysis applications which are pertinent during mineral exploration and deposit development. These applications lend additional insight during exploration planning, land acquisition, physical exploration, and development. The examples are oriented toward a hypothetical management investment policy which is based on a single criterion, a minimum 15% discounted cash flow rate of return. In reality, managements use multiple criteria. This simplification is convenient for purposes of presentation and does not invalidate the examples. Computers are useful, but not a requirement, for the applications described. The use of computers provides the results on a more timely basis at costs lower than equivalent manual computations. UNDERLYING PRINCIPLES AND ANALYSIS METHODS Data estimates are subject to uncertainty. The analyst may choose to assess this uncertainty by using one of two principles. Each principle has some advantages. The principle most commonly employed is "assumed certainty." Each financial analysis is based on one set of selected data, which may represent the average estimates, minimum expected conditions, etc. The critical data is identified by making successive calculations, varying the values used. Such studies, called sensitivity analyses, isolate the economic effect of various uncertainties, and guide the allocation of future efforts toward improving the overall accuracy of the analysis. A second principle, "assumed risk," examines the interactive effect of the current uncertainties by qualitatively assigning probability distributions to each data element. These probability distributions indicate the currently appraised chance that a given numerical value will prove to be true. The corresponding procedure, risk analysis, consists of processing many individual financial analyses, each analysis being based on randomly selected numerical values from the probabilistic distributions. The result is a numerical presentation of the uncertainty, but care must be exercised in the interpretation of results. The advantage of this procedure is the direct measurement of economic uncertainty caused by the interaction of uncertain estimates. Kennecott Copper Corp. has developed computer systems for accomplishing sensitivity and risk analyses.

Jan 1, 1970

By Lance R. Barron

Over the past decade, the U.S. Bureau of Mines (USBM) has studied longwall gate road stability at four mines in the Book Cliffs and Wasatch Plateau Coalfields of Utah. These operations are characterized by multiple-seam mining, abruptly varying cover depths to 914 m (3;000 ft), and massive rigid, sandstone units in the main roof or floor. Such conditions encourage severe bumping, roof instability, and occasional floor heave problems.' Various gate road configurations have been employed to alleviate' these problems. Although the mines have comparable basic conditions, the lithologies and qualities of the immediate roof, floor; and seam ate different in each mine and often vary in a single mine. Gate road systems that mitigate hazards in one mine may prove inappropriate in another or for different areas of the same mine. This report relates the geology of the coalfields; describes the location, geologic setting, specific mining conditions, operating history, and the USBM field study and results or conclusions for each mine; summarizes the relative performance of the gate road systems; and emphasizes the need for site-specific geotechnical data to evaluate gate road conditions and performance.

Jan 1, 1994

By Arthur E. Bruszak, Marcel Vanpée

In many practical combustion systems ignition may occur through contact with hot burned gases . Such a process plays a vital role in flame stabilization on bluff bodies . It is also of importance in the ignition of firedamp by the hot spent gases of explosives used in mines . Also , in the communication of flames through narrow channels , a problem of practical importance in flameproofing electrical equipment , the propagation of the flame is essentially a reignition process in which hot burned gases are the agent of ignition . In the actual ignition problem a great variety of conditions may be visualized . Ignition may occur where pockets of hot gases are surrounded by cold explosive mixtures or where pockets of cold mixture may be surrounded by hot gases . Alternately , a flowing stream of combustible mixture may be initially in contact with another stream of hot combustion products , or a jet of hot gases may flow into a cold quiescent mixture ; the jet may be laminar or turbulent , continuous or discontinuous . The hot gas may also consist of the oxidant ( air for instance ) and the cold combustible pure fuel . This study by the Bureau of Mines is concerned only with ignition produced by a continuous jet of gas ( hot ) flowing into a practically quiescent cold mix- The investigation of ignition by bursts of hot gases or by turbulent jets is outside the scope of this report , and work performed on this phase of the problem has been published elsewhere

Jan 1, 1963

By S. Averill, B. Schreiner, V. Sopuck

The La Ronge. Kisseynew, Glennie Lake and Flin Flon domains. the main focu for gold exploration in the southeast part of the Saskatchewan Shield, were subject to continental glacial ice advances from the northeast during the Quaternary. Based on forty-four auger hole along with surficial mapping, the general Quaternary stratigraphy in this area is observed to be composed of a lower till unit , an overlying stratified unit of glaciofluvial sand and gravel and/or a glaciolacustrine silt-clay unit. an upper till. and an upper tratified unit. The lower till is commonly found throughout the geological domains except where it has been eroded in glaciofluvial or fluvial channels. Glacial Lake Agassiz fo rmerly covered most of these prospective domains. The lacustrine deposits associated with the lake impede surficial geochemical surveys including soil. lake sediment. and biogeochemical surveys. The approximate extent of clay cover can be predicted from beach elevations. For instance. in the Waddy Lake area. clay i not known to occur above about 1,400 feet (425 m) elevation. Exploration techniques are hampered by clay in at least one third of the volcanic belt. Thi s influence is indicated by the fact that nearly all gold prospect found to date are located above 1,400 feet (425 m) while the area of clay cover is vi rtually unexplored. The upper till i related to a minor ice readvance. This till is the medium often sampled during soil surveys in the area . lts value as a geochemical ampling medium is dependent on the extent of erosional contact with bedrock highs on the lower till. Those areas which are relatively free of lacustrine and fluvial deposits are those where surface geochemical methods work best. In the Waddy Lake volcanic belt approximately 25-50% of the area may be suitable for surficial surveys. The area of the Star Lake prospect occurs above the 1,500 foot (460 m) elevation and was not covered by Lake Agas iz. The effectivene of till sampling as a surface sampling medium was tested in those areas above the clay level. Till orientat ion surveys were carried out at the Star Lake property and the Tower Lake prospect (Waddy Lake area) within the La Ronge Domain . Gold grain counts and analy es of heavy mineral concent rate from 7 kg surface ti ll samples were used to delineate dispersion trains down-ice from mineralization. In addition, the clay fraction and a 30 g (-80 mesh) subsample from the same till sample, were analyzed for gold . In the Star Lake area, ice direction is subparallel to the strike of several narrow northeast trending auriferous structures. arrow dispersion trains down-ice from known

Jan 1, 1986

Recent work on decoppering lead is reviewed CUS is formed rapidly even from dilute solutions of copper in lead. The mechanism of decoppering is discussed and an explanation for the retention of metals such as silver in lead is advanced. As decoppering tin appears to be an analogous process, the, Cu-Sn-S system is studied at 300°C.. CuS, which is not an equilibrium product, is found m decoppermg drosses. In the removal of nickel from lead, Ni3Pb2S2 is formed; preliminary measurements show the equilibrium nickel content to be greater than that obtained by stirring in sulphur. Decoppering bIsmuth IS thermodynamically favoured, but is complicated by the occurrence of CuBiS2 The Cu-Pb-S system IS the only one of the four studied where the equilibrium can be calculated simply, as the presence of ternary sulphIde or other phases invalidates calculations based on binary data.

Jan 1, 1971

By W. M. Dressel

This Bureau of Mines report describes a shaft closure demonstration project in which 11 inverted pyramid-shaped plugs were used to plug abandoned open mine shafts in Galena, KS, The inverted pyramid-shaped forms, fabricated from steelplate, were designed so that the inverted base would be larger, by 4 ft on a side, than the approximate size of the shaft opening at the surface residuum-solid rock interface. After the surface openings of the shafts were trimmed with a backhoe, the steel forms, complete with reinforcing, were lowered into the openings and filled with concrete; the remaining portions of the openings above the plugs were backfilled to slightly above the surrounding surface level with waste rock and soil. Location and elevation monuments were installed for long-tern evaluation of the success of the project.

Jan 1, 1985

By Arno C. Fieldner

In view of the widespread interest in the production of synthetic liquid fuels from solid and gaseous fuels to supplement declining reserves of petroleum, and the many requests that are now being received for information on the subject, this bibliography of Bureau of Mines contributions has been compiled. In addition to the publications issued by the Government in printed or mimeographed form, references are included to articles written by the Bureau staff for the technical press and to cooperative reports of work done jointly with States, colleges, and industries. References are given under each section in chronological order. Bureau of Mines bulletins, technical papers, and Minerals Yearbooks are printed and are obtainable at the prices indicated from the Superintendent of Documents, Government Printing Office, Washington 25, D. C. If no price is given, the publication is out of print. The price of entire volumes of the Minerals Yearbook or of reprints of certain chanters may be obtained upon request. Any orders or remittances in payment for these publications should be cent directly to the Superintendent of Documents and not

Jan 1, 1945

By G Senanayake, K Hazarika

The demand for iron-ore is ever increasing with the industry directly employing 60 500 people in a range of highly skilled roles in Australia. In the year 2019, the global iron-ore production was 2.85 billion tonnes. It is estimated that each tonne of beneficiated iron ore produces 400 kg of tailings. The IOTs are fine, dense and stable crystalline material mainly composed of iron oxides, alumina and silica. The current and most applied method of iron-ore tailings (IOTs) disposal is using subaqueous disposal of tailings in dams. The footprint generated by a tailings dam is massive and requires constant monitoring due to the possibility of a failure making the operation and maintenance of tailings dam extremely expensive. This review briefly discusses the known causes of tailings dam failures, their impact to the environment and day-to-day human life and potential applications of IOTs. The increase in water content enhances the pressure on dam walls. This in turn increases the liquefaction potential of the tailings and reduces the overall strength of the dam making it more vulnerable to failure. Potential applications of IOTs are in paints, aggregates in construction materials and bricks. The reuse of IOTs reduce waste and generates further revenue facilitating a path towards a sustainable future for the industry.

Nov 8, 2021

By John J. Peregoy, James E. Downes

INTRODUCTION The U.S. Department of Energy's Waste Isolation Pilot Plant (WIPP) is being constructed to provide permanent storage of radioactive TRU waste materials emanating from military weapons production. These wastes are contaminated with radioactive elements heavier than uranium, thus the name trans-(or beyond) uranic (Uranium wastes). The WIPP site, which is located 26 miles east of Carlsbad, New Mexico, was chosen thru a selection process after the National Academy of Sciences recommended salt deposits as a promising host strata for the storage of radioactive wastes. Throughout the United States numerous DOE facilities have produced and stored defense-generated TRU wastes. Once WIPP becomes operational in the fall of 1989, all sites may ship directly to this repository. A companion project has developed special shipping containers (TRUPACT) for safe transport of materials to WIPP. The WIPP facility is currently composed of surface buildings, three shafts, and underground storage and experimental rooms and tunnels. Frontier-Kemper Constructors, Inc. (FKCI) has nearly completed the construction of the fourth shaft, an intake shaft, to provide additional ventilation to the underground workings. PLANNED SHAFT EXCAVATION METHOD Full-face raise boring ( upreaming ) was the allowable method selected by Frontier-Kemper Constructors for the excavation of the shaft. After arrival of an oil-field type rotary drill rig in December 1987, a 9 inch diameter pilot hole was drilled from the surface to the mine level, a depth of approximately 2145 feet.

Jan 1, 1989

By A. T. Tye

This paper describing the concentrator practice of the Cananea Consolidated Copper Co. at Cananea, Sonora, Mexico, is one of a series of articles on milling methods and costs being prepared by the U. S. Bureau of Mines. The Cananea concentrator treats 2,400 tons of copper ore per day by preferential flotation, whereby the copper sulphides are floated and the iron pyrite depressed. During the first half of the year 1929 the heads to the concentrator averaged 3.29 per cent of copper, the recovery was 95.74 per cent of the total copper, and the concentrates produced contained 21.44 per cent of copper.

Jan 1, 1930

By Cedric E. Gregory

"A study of model rectangular mine shafts has been made in the wind tunnel, with the aim of reducing air-flow resistance elements to a practicable minimum. An analysis of Table 7 shows an indicated average decrease in resistance of 28 per cent by adopting the over-all modifications involved in the configurations actually tested. Much greater reductions (up to 68 per cent) are indicated by extrapolating beyond the test results directly achieved. Intermediate partial reductions in aerodynamic resistance are shown for individual modifications, such as: (1) about 3 per cent for locating the lagging in the No. 4 (inside flush) position as against the No. 1 position - 8 per cent as against the No. 2 position - and 23 per cent as compared with position No. 3; (2) about 12 per cent for using lagging instead of steel meshwork along the divider separating the skipway from the service compartment; (3) about 14 per cent for using steel gridwork ladder stagings at 3-set intervals instead of similarly spaced wooden stagings; (4) about 12 per cent for using steel gridwork ladder stagings at 3-set instead of at 1-set intervals; (5) about 13 per cent for fitting a streamlined fairing (see Fig. 5) to the upstream face of the skipway divider. Contrary to expectations, an advantage of only 3 per cent is indicated for lagging in the inside flush (No. 4) position over the outside position (No. 1). This slight gain does not appear to warrant the cost of moving the lagging. However, if the lagging is already in the No. 2 or No. 3 position, there is an 8 and 23 per cent advantage respectively."

Jan 1, 1973

By John C. Machisak

INJURY DATA and experience at coal mines in the United States for 1956 and 1956 are presented in this publication with a minimum of interpretation and comment because of the numerous tables required to afford detailed comparisons between the 2 years. Corresponding table., for 1955 and 1956 follow in consecutive order under the following general sections: (A) General injury experience: Tables I to II: contain current data on number of fatal and nonfatal injuries, frequency and severity rates, and average severity. (B) Selected injury data: Tables 12 to 77: Contain current data on causes of injuries, distribution of injuries by part of body injured, clays of disability, extent of hand and machine loading, experience by employment and production groups, and various other operating factors and physical conditions related to the occurrence of injuries at the Nation's coal mines. (C) Injury experience, by States: Tables 78 to 87: Contain data on injuries, injury rates, employment, cause of injuries, aid severity rates by States. (D) Major disasters: Table 88: Contains data on major disasters, 1947 -56. A major disaster is defined as a single accident in which, or as the result of which, five or more persons are killed instantly or died at any time thereafter. (E) Historical coal-mine-fatality experience: Tables 89 to 93: Contain data on fatalities and their causes at bituminous-coal and anthracite mines from the earliest records through 1956.

Jan 1, 1960