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By W. Bruce Montgomery

Manganese oxides occur, with some iron oxides, in small scattered lenses on property controlled by the Columbia Manganese Co. (1943) near Evington, Campbell County, Va. The company mined some manganese ore during 1917 and 1918. A preliminary examination in May 1942 indicated the possibility of finding additional ore. On August 21, 1942, the Bureau of Mines began prospecting to verify the continuity of the ore exposures. Work on this project continued until February 5, 1943. Prospecting and development work included shaft sinking, crosscutting, drifting, trenching, and test-pitting in six separate areas indicating two types of deposits. The most predominant type is a wide brecciated area in which occur lenses or pockets of nodular manganese oxides. The other type is characterized by more of a vein structure, including thin layers of manganese oxides.

Jan 1, 1949

By Lloyd R. Michels, Burke Cartwright, S. F. Ravitz

"INTRODUCTION Frequent attempts have be,made in the electrolysis of molten magnesium chloride to regenerate the electrolyte by allowing the chlorice generated at the anwdo to read with magnesium oxide and carbon within the melt according to the following reactions: (1) MgO + C + CL2 = MgCl2 + CO,(2) 2MgO + C + 2C12 = 2MgC12. + CO2.The principal advantages of such a procedure are that (1) the direct source of magnesium is magnesium oxide rather than the more expensive dehydrated magnesium chloride and (2) it is not necessary to handle or dispose of large quantities of chlorine or hydogen chloride.Grätzll 5/ proposed the use of an MgO carbon feed in a more or,less compact form in the anode compartment, of the cell. In a patent issued to Magall Aktiengecellschaft, 6/ a compact mixture of MgO and carbon is used as the anode itself. Kato 7/ and Backer 8/ add the feed in finely divided form to the surface of the anode compartment. The Bureau of Mines 2/ recently made a pilot-plant investigation of the electrolysis of suspension of MgO and carbon from chloride melts, in which it was found that although,current efficiencies of 60 to 70 percent were obtainable, the formation of sludges containing MgO, carbon, and magnesium seriously interfered with the operation of the cell,"

Apr 1, 1945

By Travis Rhoden

Merriam Webster?s Collegiate Dictio­nary (1996) defines team as ?a number of persons associated together in work or activity? and teamwork as ?work done by several associates with each doing a part, but all subordinating personal prominence to the efficiency of the whole? (page 1209). According to Dr. Geller, author of Building Successful Safety Teams: Together Everyone Achieves More (1998), a team of people working together for industrial safety consists of as few as two people or as many as fifteen who have complementary skills, assignments, or abilities for completing a particular task. Effective teams have members who share a common mission and relevant goals, and they share specific methods to reach their goals and accomplish their mission. They also have an evaluation system in place for holding themselves mutually accountable for goal-directed responsibilities.

Nov 1, 1998

By Doris M. Hyde

The impact of mining activities on the economy in both 1983 and 1984 was minimal. The most recent available data on the gross domestic product (GDP) indicated a level of $1.6 billion in 1983.2 The estimated value for the production of cement, aragonite, and salt was about $17 million in that year, down from the estimated $20 million in 1982. No data are available on the economic impact of the large petroleum refinery at Freeport on Grand Bahama Island, but it represents the major mineral-related activity. Cement production remained at only a fraction of the 800,000 tons per year of plant capacity. The offshore search for hydrocarbons continued in 1984, and some companies were about to enter the third year of seismic and geological surveying around Andros and Grand Bahamas Islands. Getty Oil (Bahamas) Co. Inc.; Breoco Ltd., a subsidiary of REO Development Corp. of Tulsa, Oklahoma; and Natomas Petroleum (Bahamas) Ltd. were the first companies to be awarded exploration licenses. These companies were committed to drilling at least one well before the end of the third exploration year. Other companies actively engaged in exploration included Exxon Corp., Atlantic Richfield Co. (ARCO), Chevron Oil Bahamas Ltd., and Esso Oil Bahamas Ltd. Geophysical Services Inc. (GSI) of Dallas, Texas, and Petroleum Services (Bahamas) Ltd. of Englewood, Colorado, ran another seismic survey line during 1984. This 1,533-mile line was in the Great Bahama Bank and Cay Sal Bank areas off the southeast Florida coast, and tied in with a 4,530-mile program GSI ran in 1981-82. These surveys were nonexclusive and publicly available through GSI.

Jan 1, 1986

By J. M. Kuchta

Ignition and flammability test methods were developed by the Bureau of Mines for use in the classification of flammable solids by the Department of Transportation. A rotating disk ignition apparatus and a flame-spread-rate apparatus are proposed for determining the ignitability and flammability, respectively, of most flammable solids. Extremely flammable solids, such as pyrophoric materials, are evaluated by determining their ease of spontaneous ignition in an environmental chamber at high-humidity conditions. Data are presented for various representative solids to show the reliability of the test methods for classifying the materials. A classification system is also proposed for use in government transportation regulations.

Jan 1, 1972

Provide guidance on the selection of millisecond initiator delays between blastholes in surface mine blasting to provide a desired degree of rock fragmentation consistent with safety and vibration considerations. The Problem Blasting remains the primary means of fragmenting, rock for all kinds of mining, quarrying, construction, and excavation activities, and it is the only practical and economic method of breaking up and moving large amounts of material such as coal overburden and stone aggregate. Because of the large amount of blasting done, typically using 4 billion pounds of explosive to break about 8 billion tons of rock annually in the United States, a small improvement in blasting performance will have a significant productivity impact. Standard blasting practices involve the selection of time delays in a blast for at [cast three purposes: (1) to control energy flow to minimize adverse vibrations, (2) to provide sufficient time relief for good rock displacement, appropriate muck pile shape for digging, and the prevention of collar violence, misfires, and flyrock, and (3) to provide an appropriate amount of interhole stress wave and gas pressure action for a desired fragmentation size distribution. Timing guidelines that exist are based on subjective observations rather than measurements, even for the relatively new casting methods. Until this Bureau study, no definitive analysis had been done to quantify the fragmentation and productivity of full-scale blast rounds as functions of precision delay timing.

Jan 1, 1989

By E. Morrice

The Bureau of Mines investigated methods for beneficiating platinumgroup metal ores from the Stillwater Complex , Montana , as part of its program to increase the supply of critical and strategic minerals and metals from domestic resources . This report presents results of a 5- day continuous campaign employing a pilot flotation mill to recover sulfide concentrate containing platinum- palladium values from anorthositic ore . A mercaptobenzothiazole - sulfuric acid reagent suite was used . The pilot flotation mill was operated at an average feed rate of 106 lb/ hr of ore . A rougher concentrate containing 8.5 pct of the feed was prepared ; it assayed 1.1 oz /ton Pt and 3.5 oz / ton Pd . Recovery of platinum and palladium were 91 and 87 pct , respectively .

Jan 1, 1965

By D. W. Frommer, M. M. Fine

"INTRODUCTION Laboratory mineral-dressing investigations covered by this report show that ores from Montgomery County, Ark., and Morgan County, Mo., are potential sources of barite and zinc. Fine grinding and froth flotation yielded drilling-grade barite from the former and chemical-grade barite and zinc concentrates from the latter.Samples from these deposits were subjected to a laboratory investigation to develop an economic and feasible treatment. The Arkansas ore, submitted by the Husky Refining Co., consisted of an intimate mixture of the economic mineral and quartz. Fine grinding and fatty acid flotation were utilized to effect a good recovery of a drilling-grade product. The other was a zinc-barite ore submitted by the Rocky Ford Mining Co., Stover, Mo. There was no problem in the recovery of zinc (most of which occurred as sphalerite), but the recovery of barite by flotation was complicated by the presence of gangue carbonates. Ultimately, an excellent recovery of barite was achieved with a relatively new type of flotation promoter, petroleum sulfonate.In recent years, barite has become one of the major industrial minerals as an essential ingredient in heavy drilling fluids, pigments, and chemicals. New sources of this important commodity are always interesting; thus, it is the purpose of this report to present information that may permit commercial exploitation of two deposits not in production."

May 1, 1952

By John R. Duda

The Bureau of Mines is developing estimates of capital investment, operating cost, and selling price for underground mines producing bituminous coal by various mining methods. This study estimates the required capital investment, operating costs, and selling prices for two hypothetical mines designed to produce 1.5 and 3 million tons per year (MM tpy)3 by using a longwall system in conjunction with a continuous-mining system. The coal properties being mined are assumed capable of sustaining a 20-year product Lon period. Wages and union welfare payments used in this study are those in effect as of December 6, 1975, as set forth under the National Bituminous Coal Wage Agreement of 1974. Costs of materials and equipment are based on January 1976 Indexes. Initial capital investment is $33.8 million for the 1.5-MM-tpy mine and $61 million for the 3-MM-tpy mine. Capital requirements, including deferred investments, were estimated to be $52.5 and $94.2 million, respectively. These figures translate into total capital investments of $34.87 and $31.31 per ton of annual production. Assuming a desired 15-percent discounted cash flow rate of return, with Federal income taxes at 50 percent, the required selling prices would be $12.06 and $10.94 per ton for the 1.5- and 3-MM-tpy mines.

Jan 1, 1976

By John E. Urosek, Dennis A. Beiter, William J. Francart

In This Chapter [Designing bleeder systems Examining and maintaining bleeder systems Evaluating bleeder system effectiveness] INTRODUCTION Bleeder systems are that part of the mine ventilation network used to ventilate pillared areas in underground coal mines. Pillared areas are those in which pillars have been wholly or partially removed, including the areas where coal has been extracted by longwall mining. Bleeder systems protect miners from the hazards associated with methane and other gases, dusts and fumes, and oxygen deficiency that may occur in these mined-out areas. Effective bleeder systems control the air passing through the area and continuously dilute and move any methane-air mixtures and other gases, dusts, and fumes from the worked-out area away from active workings and into a return air course or to the surface of the mine. A bleeder system includes the pillared area (including the internal airflow paths), bleeder entries, bleeder connections, and all associated ventilation control devices that control the air passing through the pillared area. Bleeder entries are special air courses designed and maintained as part of the mine ventilation system. [This chapter focuses on the design, examination, maintenance, and evaluation of bleeder systems in underground coal mines.] The history of coal mine explosions in the United States is a reminder of the importance of adequate ventilation. Some of those disasters were the result of inadequately ventilated pillared areas. The importance of developing bleeder systems to ventilate these pillared areas and evaluating the bleeder system’s effectiveness is reflected in present-day federal regulations. For more information on bleeder systems, see Tisdale [1996] and Urosek and Francart [2002].

Jan 6, 2006

By Susanne Hering, Brent Kirby, Charles D. Litton, Tracy Allen, Kirk R. Smith, Rufus Edwards

In developing countries, high levels of particle pollution from the use of coal and biomass fuels for household cooking and heating are a major cause of ill health and premature mortality. The cost and complexity of existing monitoring equipment, combined with the need to sample many locations, make routine quantification of household particle pollution levels difficult. Recent advances in technology, however, have enabled the development of a small, portable, data-logging particle monitor modified from commercial smoke alarm technology that can meet the needs of surveys in the developing world at reasonable cost. Laboratory comparisons of a prototype particle monitor developed at the University of California at Berkeley (UCB) with gravimetric filters, a tapered element oscillating microbalance, and a TSI DustTrak to quantify the UCB particle monitor response as a function of both concentration and particle size and to examine sensor response in relation to changes in temperature, relative humidity, and elevation are presented here. UCB particle monitors showed good linearity in response to different concentrations of laboratory-generated oleic acid aerosols with a coarse (mass median diameter, 2.1 µm) and fine (mass median diameter, 0.27-0.42 µm) size distributions (average r2 = 0.997 ± 0.005). The photoelectric and ionization chamber showed a wide range of responses based on particle size and, thus, require calibration with the aerosol of interest. The ionization chamber was five times more sensitive to fine rather than coarse particles, whereas the photoelectric chamber was five times more sensitive to coarse than fine. The ratio of the response between the two sensors has the potential for mass calibration of individual data points based on estimated parameters of the size distribution. The results demonstrate the significant potential of this monitor, which will facilitate the evaluation of interventions (improved fuels, stoves, and ventilation) on indoor air pollution levels and research on the impacts of indoor particle levels on health in developing countries.

By Charlie Wyche

In 1980, gold, silver, and pit and quarry construction materials were the principal minerals produced in the Dominion of Fiji. The combined value of these minerals totaled some $7.2 million,2 over 85% of all mineral production, Production of cement, sand and gravel, and quarry products continued to increase, but gold and silver production from Fiji's only operating mine declined slightly from the previous year's level. Mineral exploration has been carried out by U.S., Australian, British, Canadian, West German, and South African companies since the early 1960's, and a high level of activity was maintained throughout 1980. At the end of 1980, some 40 mineral prospecting licenses covering over 4,300 square kilometers were in force, and 19 applications were under consideration by the Mineral Resources Department. Total expenditures by mining companies on land base projects exceeded $6 million in 1980.

Jan 1, 1982

By Loren R. Anderson

Traditionally, an evaluation of the safety of slopes has been based on computing a safety factor against failure. In computing the safety factor, the geometry of the slope, the soil parameters and the pore pressures are treated as deterministic quantities even though they are known to be random variables. A pseudo-three-dimensional probabilistic slope stability model has been developed that treats shear strength as a random variable. The model uses the probability of a slope failure as an assessment of slope reliability. The model can accommodate zoned embankments of soil in which the strength is described by the Mohr-Coulomb strength envelope. Autocorrelation functions are used to describe the spatial correlation of the strength parameters, c and tan ø. Model error can also be included in the analysis. The model has been applied to an existing tailings dam and to several hypothetical examples. These examples are presented to illustrate the influence of the choice of the soil strength variability parameters on the probability of failure. The results show that the critical failure surface based on the minimum safety factor is not necessarily the failure surface that will yield the maximum probability of failure. The analysis of the tailings dam shows that variance reduction can be large and that the model error is the dominant source of uncertainty for the embankment analyzed.

Jan 1, 1982

As longwall shields are lowered in preparation for advance, dust from the canopy falls directly into the air stream with the potential of becoming entrained. Historical dust sampling data from the early 1980s shows that shield advance contributed an average of 12 percent to the airborne respirable dust levels found on longwalls in the United States. Data from the 1990s indicates that shield dust liberation had increased to an average of 23 percent. Increased longwall production levels over this time resulted in the need to move a larger number of shields during each shift, while an increase in air velocities on the face was also occurring. These factors combine to suggest that greater quantities of shield dust are being entrained into the face air. A series of controlled laboratory tests were conducted in a test stand simulating shield dust entrainment to evaluate changes in airborne respirable dust levels at different air velocities. Significant differences in respirable dust entrainment were observed. The test facility, test methodology, and dust sampling results will be reviewed and discussed

The title of this book, The Phoenix of Natural Disasters: Community Resilience is aptly chosen. ?The Phoenix is a mythical bird that never dies; the phoenix flies far ahead to the front, always scanning the landscape and distant space. It represents our capacity for vision, for collecting sensory information about our environment and the events unfolding within it.? (source: The Feng Shui Handbook, feng shui Master Lam Kam Chuen.) There are Chinese, Japanese, Russian, Egyptian, and Native American counterparts of the phoenix. All of these birds are identified with the sun and depicted as rising from the ashes ? living again. This is the essence of a community after a natural disaster ? they live again. The Phoenix of Natural Disasters: Community Resilience is edited by Kathryn Gow and Douglas Paton who have done an excellent job of creating a relatively seamless transition between chapters with different authors. The content is organized well with the first chapter providing an excellent overview of what is to come and each chapter including an abstract clarifying the focus of the chapter.

Jan 1, 2009

By Henry Kreisinger, F. K. Ovrız

Some of the investigations conducted by the Bureau of Mines have for their object the collecting and disseminating of information regard- ing methods by which the fuels of the country may be most effi- ciently used. As the analysis of flue gases tends to develop better methods of firing, which in turn reduces waste of fuel, the Bureau of Mines in this bulletin presents for the benefit of those in charge of boiler plants and all other persons interested detailed information on methods of sampling and analyzing flue gases, and on the utilization of the analyses in promoting boiler-room economy. This bulletin is intended to be a companion to Technical Paper 80," and is written in plain and nontechnical language, as far as pos- sible, so that it may be readily understood by persons who have not had the advantage of a technical education. Whenever possible, illustrations of apparatus and methods of handling have been used rather than elaborate descriptions. The material presented in this report is arranged in two parts. The first part contains the description of the apparatus and the methods used in sampling and analyzing flue gases. The second part gives experimental results obtained with the different methods of sampling and collecting flue gas that are recommended in the first part of the report. Only simple apparatus and methods are considered, as they are accurate enough to show the large heat losses due to the use of too much air, and are also accurate enough to indicate any incomplete combustion losses of economic importance. Without doubt the loss due to large excess of air is the greatest one in the boiler room, and can usually be greatly reduced by making proper use of gas analysis. Before engineers in the isolated industrial plants can be induced to analyze for small traces of combustible gases, they must be first taught how to analyze for carbon dioxide (CO), and they must learn to appre- ciate the great possibilities of reducing loss from large excess of air. Furthermore, in the face of the great difficulty of obtaining a fair

Jan 1, 1915

By L. A. Neumeier

The Bureau of Mines evaluated the properties of a Zn-0.75 pct Cu-0.12 pct Ti alloy extruded at temperatures between 400° and 720° F. The extrusions were made with a reduction ratio of 28-to-l and at relatively slow speed. Rod was also extruded at 560° and 640° F with a reduction of 255-to-l. With increased extrusion, temperature, extrusion pressures decreased substantially and creep resistance of the rod improved significantly. Coefficients of thermal expansion were low in the long rod dimension. Microstructures, hardness, and tensile properties were also evaluated, and a limited evaluation was made of bend ductility at 32° F for the rod extruded with the 255-to-1 reduction.

Jan 1, 1969

By Jack C. White

This U.S. Bureau of Mines report assesses the resource potential of trace metals present in commercial Ti mineral concentrates. Metals of greatest interest: are those defined as "strategic and critical" by the U.S. Congress in 1981. Metals of interest in Ti mineral concentrates are Cb, Cr, Ta, Th, U, V, and Zr. Commercially available Ti mineral concentrates were studied. Characterization and analysis of major and minor constituents were performed by X-ray diffraction, neutron activation, inductively coupled plasma emission, atomic absorption, and classical wet chemical techniques. Of the metals investigated, the Cb, Ta, and V content of some concentrates may be a significant potential resource, depending on their amenability to recovery.

Jan 1, 2010

By Richard H. Spencer, Warren G. Bender

Since the passage of the Coal Mine Health and Safety Act of 1969, the Bureau of Mines has made many advances in mine communications. These efforts have resulted in the following developments and demonstrations: • Surface-to-surface electromagnetic transmission of baseband voice signals through overburdens as deep as 600 feet. This transmission was achieved with equipment from the Interim Mine Rescue and Survival System Program, and demonstrated that baseband voice communications could be obtained through these overburdens in the absence of mine-generated noise; that is, when the mine power system was shut off. However, during mine operational conditions, the mine-generated noise proved to be so large that effective baseband voice communications to the desired depths could not be effected. • The development of beacon transmitters for locating trapped miners. This work was again the outgrowth of the Interim Mine Rescue and Survival System. Extensions of this work have led to reliable detection and location of trapped miners to depths of 1000 feet. The system, which makes use of a loop antenna deployed where the trapped miner is located, uses low-duty-cycle, tone-burst transmission. Portable tuned receivers and loop antennas are used on the surface to determine the location of the trapped miner. An extension of this work has led to a call-alert paging system concept, wherein a transmitter, similar to that used in the trapped miner system, is used to audibly and/or visually alert key mine personnel carrying pocket receivers that they are wanted at the nearest mine telephone. In addition, a roof-bolt paging system has been developed, wherein commercial paging and mine carrier phone equipment are used in conjunction with a long-wire "roof bolt" antenna to page individuals and relay to them short voice messages.

Jan 7, 1975

By G. H. Cobb, J. L. Johnson, H. H. Heady

An infrared absorbance technique is described for analyzing anodic gases produced during the electrowinning of uranium , thorium , and rare - earth metals in molten fluorides . Typical components determined qualitatively in a gas sample are CO , CO₂ , CF4 , C₂ Fe , C3F8 , COS , CS₂ , and SiF4 . About 20 minutes are required to record and interpret the spectrogram , and report quantitative results for CO, CO₂ , CF4 , and SiF . The procedure is used for control during electrolysis .

Jan 1, 1964