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By John Ward Smith

Methods for estimating the amounts of nahcolite, dawsonite, and the sum of these two sodium carbonate minerals from oil-yield assay data are developed and evaluated for Green River Formation oil shales from the saline section of Colorado's Piceance Creek Basin. Derived statistically, these estimation methods depend on the fact that these minerals yield water and gas measured during oil-yield assay. The estimation procedures yield values for nahcolite and nahcolite-plus-dawsonite of sufficient accuracy for stratigraphic plotting and correlation, whereas estimates for dawsonite are more generalized. However, resource estimates and reserve computations for both nahcolite and dawsonite accurate within 10 percent of the real value are readily available by summing the mineral amounts calculated by the procedures presented. These estimation procedures are applicable to oil-yield assay data on core samples from more than 30 coreholes which have penetrated the saline section of the Green River Formation in Colorado.

Jan 1, 1972

By Joan C. Biordi

The Bureau of Mines used molecular beam-mass spectrometry to determine the microstructure of a 10.1% CH4-2l.2% 02-67.6% Ar-1.1% CF3Br inhibited flame and its uninhibited analog, both stabilized at 32 torr on a cooled flat-flame burner. Composition profiles of atomic, radical, and stable species and temperature profiles for both flames were obtained and compared. Kinetic analyses of the profiles yielded values for the rate coefficients of several elementary methane flame reactions and information on the reactions of formation and decay of the observed halocarbon species. CF3Br is judged to decay by thermal decomposition as well as by abstraction reactions, and the fluorocarbon chemistry occurring in the inhibited flame is due primarily to CF2 radical reactions. Rate coefficients and mechanisms for reactions of the inhibitor-related species are given.

Jan 1, 1978

By W. E. Lamont

Flotation studies of phosphate-bearing waste pond materials, low-grade washer products, and raw ores, all from the Tennessee brown phosphate district, showed that these types of materials could be treated without des liming to recover high-grade phosphate concentrates. The investigation showed that fine grinding before flotation was a requisite for increased recovery of the phosphate values and that the optimum pH conditions were in the range of 10.0 to 10.5 when using anionic collectors. Multiple-cleaning of the rougher phosphate concentrate was required to produce high-grade concentrates. Phosphate recoveries ranged from 60 to 82 percent and were inversely related to the grade of concentrate produced.

Jan 1, 1972

By H. C. Miller

[California's sensational rise to supremacy as an oil-producing State in 1923 was accompanied by a loss of 62 lives. These 62 deaths were from oil-producing accidents alone and do not include fatalities at the refineries, on tankers, or on any work not directly connected with the drilling for and the production of oil. The number of facilities for 1923 was 82 per cent greater than in 1922, the next most fatal year, with a record of 34 lives lost. The data submitted in Table 1 show that for the calendar years 1917 to 1923 inclusive, an average of 4.74 million barrels of oil were produced per Vitality in the California oil fields. On this basis, the record for 1923, hough a trifle below the average, shove up slightly better than that for 1922.]

Jan 1, 1924

By Joseph B. Huvos

Said to be one of the world's most under-developed countries, Benin had a gross national product (GNP) estimated at $1 billion in 1980.2 Contribution of the mineral industry such as cement and limestone to the GNP was negligible, but exploration of mineral potential continued Minerals.-The United Nations Development Program (UNDP) conducted an investigation of three deposits from 1977 to 1980: Phosphates (Mekrou), gold (Perma), and chromite (Buem). A phosphate rock deposit containing about 4.5 million tons recover- able by opencast techniques was discovered. It was not known if the gold and chromite deposits were recoverable economically. Iron ore deposits of some 230 million tons near Loumbo-Loumbo are at present not exploitable because of lack of infrastructure in the northern part of the country. Geologic mapping with British and French assistance was also pursued in 1980.

Jan 1, 1982

By Parviz F. Rad

The Bureau of Mines conducted groove cutting experiments in marble, lime-stone, granite, and quartzite with a 7-inch disk cutter under a normal thrust of 7,000 lb. The values of muck weight per unit length, specific energy, cutting coefficient, and groove depth for each of these rocks were determined for groove spacings ranging from 0.1 to 4 inches, and from these results the values of optimum and critical spacing were computed" The results indicate that compressive strength may be used to predict some of the cutting characteristics of the independent grooves. Considering all the cutting characteristics, particularly those for the interacting grooves, Shore hardness, coefficient of rock strength, and torsional velocity correlate with cutting characteristics better than do other physical properties. Some of the field applications of the principles established in this report are identified.

Jan 1, 1974

By Paul R. Amyotte, Omotayo Kalejaiye, Kenneth L. Cashdollar, Michael J. Pegg

The Siwek 20-L chamber is widely used throughout the world to evaluate the explosibility of dusts. This research evaluated the quality of dust dispersion in the Siwek 20-L chamber using Pittsburgh coal, Gilsonite, and purple K dusts. A Pittsburgh Research Laboratory (PRL) optical dust probe was used to measure optical transmittance through the dust cloud at various locations within the chamber. A total of 540 tests were performed, with triplicate tests at five nominal dust concentrations and six locations. The two standard dispersion nozzles (rebound and perforated annular nozzle) were compared. The transmissions corresponding to the normal ignition delay period were used to: (a) determine variations in spatial uniformity of dispersion obtained with both nozzles; (b) make comparisons between the experimental transmission data and those calculated from theory for the three dusts; and (c) make comparisons with transmission data measured in the PRI, 20-L and Fike 1 -m3 dust explosion chambers. The uniformity of dispersion for the three dusts was similar with both nozzles, despite the differences in nozzle geometry and mode of operation. Transmission data of the three dusts were all significantly lower than those calculated from theory. This was discovered to be, in part, due to significant reduction in particle size that occurred during dispersion. By measuring particle sizes before and after dispersion, values of 60%, 50%, and 20% reduction in particle size (based on the surface weighted mean diameter) were obtained for Pittsburgh coal, Gilsonite, and purple K, respectively. Transmission data from the PRL 20-L, Fike 1 -m3 and the Siwek 20-L chambers indicated comparable results in terms of uniformity of dispersion. However, transmission data from the Siwek 20-L chamber were significantly lower than those of the PRL and Fike chambers. Again, this was attributed, in part, to the significant reduction in particle size that occurred during dispersion in the Siwek chamber. The design of the outlet (dispersion) valve of the Siwek 20-L apparatus charge vessel was largely responsible for the particle break-up. The contribution to particle break-up by the dispersion nozzles and the high level of turbulence in the chamber were found to be minimal. This is a significant finding in that the dust particle size tested for explosibility in the Siwek chamber is considerably smaller than the original dust sample.

By M. J. Ankeny

The expression "firing open, unconfined shots," as used in this circular, means the firing of explosive charges not confined in boreholes. Examples are the so-called mudcap shots, adobe or dobe shots, or bulldozing shots consisting of explosive charges placed on, under, or between rocks for the purpose of breaking them. The practice of firing open, unconfined shots is not uncommon in coal mines, despite the fact that numerous mine explosions and dust ignitions have resulted from this practice. The usual method of preparing such shots is to place the explosive with its detonator on top of a piece of rock or coal and cover it with clay, loam, sand, or road dust; frequently no covering of any kind is used. In some mines, an open charge of explosive is placed on timbers to dislodge them or in crevices in the roof to break down loose rock that cannot be dislodged with a bar or pick. The explosive charges may be made and fired singly, although sometimes several charges are placed on one large piece of rock with a detonator in each charge, and all charges are fired simultaneously. Although it is general practice to use permissible shot-firing devices, which will not ignite gas or dust to fire these charges, electric power from the regular mine circuits is sometimes used. When the shot is fired, any coal dust that may be present is thrown into suspension by the blast and may be ignited by the intense hot flame of the explosive or by an arc or spark at the leg wires or the end of the firing leads if power from the regular mine circuit is used to fire the shot. Even if there is not enough coal dust present to form a dust cloud, open, unconfined shots can readily ignite methane.

Jan 1, 1952

By Jack R. Woodyard

Bonding angles, promotion energies, and relative atomic sizes can be estimated through the solution of a set of algebraic equations generated from simple atomic models, and quantum mechanical parameters such as bond strength can be estimated from simple, hydrogenic form-wave functions. The precepts of The Engel-Brewer Theory are melded with the "Crystal Approximation Model" to produce atomic-structure models making these predictions, The two-valence-electron case is presented in this report. For the candidate atoms Be, Mg, Ca, Sr, and Ba the calculated promotion energies agreed within a few percent of their experimental values. These atomic parameters determine the possible crystal structure of the candidate atoms when alloyed. This is part of the effort at the U.S. Bureau of Mines to develop methods for alloy design in response to requirements for new high-performance alloys that conserve critical or rare materials.

Jan 1, 2010

Publicize the valuable information resources covering research conducted by the U.S. Bureau of Mines (USBM) and other federal laboratories that may be of interest to USBM customers. Access to this information is important for promoting further research and in transferring the technology to the end user. USBM Information Resources The USBM serves as the Nation's premier agency for mining- and minerals-related research. In sharing the benefits of this research with American industry and the American people, the USBM supports information systems outlining this vast array of technical knowledge. The USBM is dedicated to making its technology readily available and will continue to expand its electronic communications capabilities. The following resources provide instant access to USBM information. U.S. Bureau of Mines Bulletin Board. The Bulletin Board is a free service accessed by computer modem. All that you need are a computer, a modem, and communications software. The telephone number for the Bulletin Board is 202-501-0373; for information on using the system call 202-501-0406. Use X-modem protocol set to 1200, 2400, or 9600 baud, 8 data bits, and 1 stop bit (8,N,1). The information on the system can be viewed or downloaded. This service includes the following: announcements on Bulletin Board and other USBM activities; mineral news, features, and press releases from the Bureau's Office of Public Information; a list of recent publications and articles by USBM authors; mineral commodity data and Mineral Industry Survey reports; USBM Technology News, concise factsheets announcing milestones in USBM research and technology; a current list of computer products available from the USBM and the National Technical Information Service (NTIS); and a listing of cooperative research opportunities with the USBM.

Jan 1, 1995

By A. J. Kraemer

The Bureau of Mines for a number of years has been carrying on an investigation of properties of crude oils from producing fields in the United States and has published a series of reports on different fields, including oil fields of Texas3. Production Data The Spindletop field was discovered in 1901 when the pay sand was found at deaths of about 800 feet. During the following twenty-five years a number of attempts were made to find a deep productive sand. All attempts sere failures until a roll drilled by the Yount Lee Oil Company found oil late in 1925. An intensive drilling campaign began at once, and the production of the Spindletop field increased to a daily average of 93,217 barrels in September, 1926; the present production is estimated at 66,000 barrels doily. Tile following table taken from the Oil and Gas Journal for February 10, 1927, shows the daily average and the total production by ninths for 1926.

Jan 1, 1927

By M. O. Magnuson

As part of an experiment in the restoration of lands strip-mined for coal, revegetation studies were conducted at three backfilled strip-mine sites in north-central Pennsylvania. The sites were subdivided into plots that were given varying amounts of lime and fertilizer. In tests conducted cooperatively with State and Federal agronomy experts, the plots were then planted with a variety of trees, shrubs, and grass-legume mixtures. Initial tree and shrub survival was not appreciably affected by lime and fertilizer applications where the spoil pH was above 4.5. Of 14 species of trees and shrubs tested, Norway spruce, black locust, Japanese larch, pitch pine, and white pine were the hardiest. The ground-cover percentage of grass-legume mixtures in the second growing season was substantially increased by using lime and fertilizer. Mixtures comprised partly of fescue were the most satisfactory.

Jan 1, 1968

By Robert L. Chufo

The paper, "An Electromagnetic Roof and Rib Thickness Sensor" presented at The 12th WVU International Mining Electrotechnology Conference in 1992, presented the results of roof coal thickness measurements in underground mines and rib coal thickness measurements in highwall mines. The microwave sensor described uses a unique spatial modulation scheme created by antenna motion, along with frequency domain signal processing, to solve the problem of media, target, and antenna dispersion. This paper further describes the advantages of the unique frequency domain signal processing technology chosen by the U.S. Bureau of Mines in extending previously reported one-dimensional thickness measurement technology to the generation of a full three-dimensional underground image of the underground environment. The electromagnetic signature of a media, whether it is coal or other geological material, is its permeability and permittivity and the effect on the velocity and amplitude of an electromagnetic wave as it passes through. High-quality imaging cannot occur without the identification of, and correction for, the permittivity and permeability of each layer of a multilayer geological deposit. Clutter, or any signal that can interfere with target discrimination, usually comes from objects in the field of view for which there is no design control. These are nuisance targets with possibly very high contrasts compared to the real target. The only proven tool to reduce clutter is to increase spatial, spectral, and polarization diversity. This paper will describe some techniques being used by the U.S. Bureau of Mines to increase the information content of both single-dimensional and three-dimensional imaging systems through the identification of media distortion mechanisms made possible by the use of spatial/spectral sensor technology. These techniques will permit high quality imaging in an environment where the data is corrupted by dispersion and clutter.

To develop a quick, safe, and effective method that allows workers at mineral processing operations to clean their dust-soiled clothing periodically throughout the workday. Background Reducing workers' respirable dust exposure to silica and other harmful dusts and contaminants is an ongoing goal in the U.S. mining industry. One area of known worker exposure is from contaminated work clothes. A U.S. Bureau of Mines report documented a number of cases where a tenfold increase in a worker's dust exposure was measured from contaminated work clothes. In these cases, the dust emitted from clothing caused the worker's dust exposure to exceed the permissible exposure limit in less than 2 hours. The most effective way to eliminate this dust source is to have workers clean or change their work clothes. There are two federal regulations that impact the clothes-cleaning process. The first states that at no time shall compressed air be directed toward a person, but that when compressed air is used, then all necessary precautions shall be taken to protect persons from injury. The second regulation states that compressed air should only be used for cleaning purposes when it is less than 30 psi and used along with personal protective equipment. For the mining industry, by default, the only approved method to perform clothes cleaning is to have workers vacuum their clothes using a HEPA filter system. This is very difficult and time-consuming and, in most instances, not very effective. Most workers would prefer to use a single compressed air hose to blow dust from their work clothes. However, not only is this method prohibited by law, it usually creates a significant dust cloud in the work environment and contaminates coworkers.

May 1, 2005

By Ann G. Kim

Samples of gas were obtained directly from the coalbed during drilling of horizontal and vertical boreholes in six different formations. The samples were analyzed by gas chromatography for C1 to C5 hydrocarbons and for O2, N2, H2, He, and Co2. Methane in the gas varied from 63 to 99 percent; carbon dioxide from 0.1 to 15 percent. The CH4/CO2 ratio varied and showed no apparent correlation with age, rank, or bed. The majority of samples contained ethane, propane, and butane; hydrogen and helium were found in some samples. Oxygen and nitrogen were usually present, possibly as a result of air contamination. A more extensive sampling program would be necessary to establish relationship between the amount and composition of the gas in the coalbed and other factors.

Jan 1, 1973

To expediate the transfer of technology from Bureau laboratories into new products and processes that enhance the economic competitiveness of the U.S. mining and minerals industry in world markets. Background The U.S. Bureau of Mines and various members of the industry are concerned about the current technology challenge to the minerals industry in the United States. They arc working together to delineate ways of enhancing the mineral industry's technology base. More emphasis is being placed on collaboration between the government, academia, and industry to formulate the innovative revolutions needed to maintain our technology edge. Through these partnerships, real issues and problems can be identified, the industry's needs as customers can be defined, and research and development activities can be tailored to meet these needs. Now is an especially exciting time in research because some special opportunities exist to encourage private industry to capitalize on Federal laboratory research and development. These opportunities arc called CRADA's. What Is A CRADA? The Congress recently enacted a mechanism that enhances collaboration between industry and government through the Technology Transfer Act of 1986. A key lea lure of this Act is a provision through which Cooperative Research and Development Agreements or CRADA's can be developed to encourage industry and government to work together and stretch their research budgets. By entering into a CRADA, a private, non-Federal company can cost-effectively perform research by sharing the costs of this research with the Federal Government. The agree¬ment involves no transfer of funds from the Government. The Government agrees to provide personnel, services, facilities, equipment or other resources (but nut funds) and the non-Federal party agrees to provide funds, personnel, services, facilities, equipment, or other resources needed to conduct a specific research or development effort.

Jan 1, 1992

By S. J. Schatzel, J. Cervik, A. A. Campoli

The cross-measure borehole technique is being studied by the Bureau of Mines as an alternative to the use of surface gob boreholes as a means of controlling methane in gobs during longwall mining. Small-diameter holes are drilled from underground locations into strata overlying the mined coalbed. When the roof strata are fractured by the mining opera- tion, a partial vacuum applied to the boreholes draws the methane out of the fractured strata and prevents it from entering the mine ventilation system. Tests in the Upper Kittanning Coalbed showed that 50 pct of the methane produced by the longwall mining operation was captured by the cross-measure boreholes. Borehole inclination and penetration into the gob are two important borehole parameters that affect the performance of the cross-measure borehole system.

Jan 1, 1983

This part of the final report treats some problems related to coal mine carrier frequency communication systems using the trolley wire/track transmission line. This work was undertaken for a brief period of time during the summer of 1972 to help understand, quantify, and improve some of the trolley wire carrier system behavior observed and/or predicted. Calculations and estimates of transmission line characteristic impedance, inductance and capacitance per unit length, mine motor loading effects, parallel line effects, and connection impedances are presented in Chapter I. Chapter II treats the design of r-f isolators for reducing the undesired and troublesome r-f loading that mine motors present to the trolley transmission line. Chapter III treats a diversity method for combatting standing wave nulls. I. CALCULATIONS RELATED TO TROLLEY WIRE COMMUNICATIONS A. ESTIMATION OF INDUCTANCE AND CAPACITANCE PER UNIT LENGTH OF TROLLEY LINES To estimate the L and C per unit length of trolley lines, we use the eccentric line model of Section G of this Chapter, "Characteristic Imped¬ance Estimates for Mine Trolley Lines." The capacitance per unit length for an eccentric line is given by (1)

Jan 1, 1974

By Elaine T. Cullen, Albert H. Fein

Federal law mandates that all miners receive safety and health training when first entering the mining industry and at least 8 hours annually thereafter. Although the mining industry has historically relied on an experiential master-apprentice model for training new employees, the formal safety training provided to miners is generally done in a classroom, with mixed results. In a series of stakeholder meetings held by NIOSH across the West in 1997-2000, trainers identified significant gaps in materials that were available to teach new and experienced miners. They asked whether NIOSH could develop effective materials to fill these perceived gaps, as well as make training more effective for those who were required to attend, but who often refused to be attentive. Adult learning theories, social learning theories, mentoring, and storytelling were all employed in the development of a series of safety training videos that have become very popular in the mining industry. This Report of Investigations describes the theoretical frameworks that were used, the process that was developed to produce the videos, and the results of the evaluations as to whether or not they were effective in training new and experienced miners.

Jan 8, 2005

By Lester G. Morrel

THE RICH and varied occurrences of metallic ores in Australia, extensive nickel deposits on New Caledonia and phosphate rock on several widely scattered small islands were important aspects of the economy of the South Pacific area. Relatively small quantities of gold and nonmetallic minerals produced in New Zealand, Fiji, and the Territory of Papua-New Guinea remained important to the domestic economies of these islands, but had little importance to overall world mineral supplies. The value of mineral commodities produced in this area in 1964 was estimated at $658 million,3 compared with $585 million in 1963. The year's greatest commodity gains were in bauxite and aluminum, beryl concentrate, manganese ore, nickel smelter products, tin, and coal. Annual increases were recorded in virtually all countries and possessions in the area except Papua-New Guinea, where the drop in output of alluvial gold accounted for a decline of about $160,000. Mineral industry activities in Australia overshadowed those in all other parts of the South Pacific in 1964. Outstanding developments were the sales contract negotiations and physical preparation for exploiting the rich iron ore discoveries in Western Australia, the initiation of domestic crude oil production, the commissioning of two new steal mills and an alumina refinery and a start on the new alumina-aluminum project based on Cape fork bauxite deposits. The principal mineral development in 1864 in New Zealand was the progress on plans of the Newzealand Steel Co. to use indigenous iron sans as the resource base for a local steel industry. In New Caledonia, additions and expansion of the nickel mining and smelting facilities continued throughout the year. Plans for extensive geophysical studies were announced by the Government Geological Departments of British Solomon Islands and Fiji.

Jan 1, 1966