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By Frank K. McIntosh

The Wood mine area was investigated by the Bureau of Mines in -1941 by a magnetic survey and a gravitational survey. Surface trenches were excavated, and diamond-drill holes were bored at the strongest anomalies developed in common by the two surveys. In the last century', several widely separated bodies of chromite with some magnetite had been exploited in a 'serpentine belt near its contact with schist. At one time this district held a virtual monopoly on the production of chromite. Known ore bodies now are exhausted. Owing to the relatively high specific gravity of chromate compared to normal rocks, a gravitational survey was run to determine which magnetic anomalies were worthy of diamond drilling. Linear feet of trenching totaled 1,710 feet. Ten holes were diamond drilled, which totaled 2,272 feet. The log of the drilling is shown in the text in a tabulation of drill-hole data.

Jan 1, 1948

By C. A. Komar

Renewed interest in the underground gasification of coal evolves from comprehensive studies of earth fracture systems that indicate that the movement of fluids can be controlled in the coalbed. In particular, directional property studies of natural microfissure occurrence, permeability, ultrasonic velocity, tensile strength, and orientation of intervals of inherent rock weakness, together with geologic structure setting and fracture trace analysis, can predict the gaseous flow paths in the coalbed. Having this information, the dominant direction in which gases generated and/or liberated by heat would move can be determined so that appropriate well patterns can be developed. Together with advances made in drilling technology that permit long horizontal holes to be drilled through the coal seams, tests can be conducted to determine whether directional control will permit devolatilization of the coalbed and gasification of the remaining hot coke in a systematic manner to produce a low-Btu gas suited for the generation of electricity.

Jan 1, 1973

By J. W. Holcomb

Many mines are opened into the coal beds by shafts; and, at some of these operations, the same cages or skips that are used for hoisting coal also are used for transporting men into and out of the mines. At some mines, separate man-and-material shafts are maintained, and the cages in these are utilized for transporting men and supplies only. In most instances, these cages are operated either singly or in pairs by a hoisting engine installed in a building near the shaft. Single ropes from the tops of the cages pass over bull wheels on the head frame to either electrically or steam-driven hoisting engines that require engineers to operate them. There are records of several instances where hoisting engineers have become incapacitated suddenly while hoisting men, and the passengers on the cages were killed or injured. Where the same cages are used for hoisting cars of coal and for lowering and hoisting men, especially where self-dumping cages or skips are used, safety pre¬cautions must be taken, such as providing steel bonnets for the cage deck, enclosed sides, adequate handholds, gates for closing the end openings, safety catches, and locking devices to prevent accidental dumping. Some of the newer hoisting installations are of the elevator type; where an operator rides in the cage in the same manner as an elevator operator in a building. These cages have single or multiple decks and are primarily for transporting men; but, in some instances, supplies also are transported. They are a great improvement over the installations where the same cages are used for hoisting cars of coal and transporting men.

Jan 1, 1952

By H. W. Davis, W. W. Adams, O. E. Kiessling

"Current economic problems frequently have focused attention upon the lack of adequate quantitative information indicating the relationship between human effort and output in various branches of the mineral industry. With the exception of complete records covering coal mining, only scattered information on the units of human energy required to produce a unit of raw material is available for most of the important industrial minerals. Fortunately a virtually complete statistical record is available covering this phase of the iron-ore mining industry.For many years iron-ore mining companies, whose interest in safety work is well-known, have reported annual data on employment to be used in the compilation of accident statistics. These data on hours of labor and other detailed employment information have been correlated with the statistics on production also reported annually by producers. The outstanding trends shown by this composite record for the 10-year period 1923-32 are included in the following discussion, supplemented by a summary table that presents the principal statistical background of the study. 5The substantial reduction in the number of men needed to produce the annual iron-ore requirements of the United States, as shown strikingly in the graphs, illustrates that in iron-ore production improvements in technology have been consistently winning a battle over the difficulties of nature. In 1923, for example, 41,294 men working 107,551,244 hours were required to produce 69,351,442 gross tons of merchantable ore, equivalent to an average output of 0.645 ton per man-hour. In 1929, however, only 30,763 men working 77,111,686 hours 'zero required to produce 73,027,720 tons of merchantable ore, equivalent to an average output of 0.947 ton per man-hour. Thus, from 1923 to 1929 the average number of men working decreased 25.5 percent and the total man-hours worked 28.3 percent, while the average output per man-hour increased 46.8 percent and total merchantable ore production 5.3 percent."

Feb 1, 1935

By Herbert H. Fields

The Bureau of Mines has been promoting health and safety in mining since its establishment in 1910. One area of research covers methane control in coalbeds; this report describes a multipurpose borehole used for both degasification and the production of commercial-quality gas. The multipurpose borehole was drilled into a barrier pillar, and seven horizontal degasification holes and one pressure point hole were drilled radially out from its perimeter. On January 28, 1974, after 505 days of degasification, a compressor was installed to the exhaust stack of the multipurpose borehole (1), and pipeline--quality gas was introduced into a commercial pipe-line. As of February 4, 1975, over 171 million cubic feet of gas had been purchased by the gas company. The in situ pressure at a depth of 200 feet into the coalbed and the average gas flow and water flow from the degasification holes as they were completed and closed off were 203 psig, 1,200,000 cfd, and 6.8 gpm, respectively. Twenty-four hours after the seven holes were connected through individual pipes to the atmosphere, the total gas and water flows and the in situ pressure dropped, respectively, to 971,000 cfd, 1.3 gpm, and 18 psig. Five hundred days later, the corresponding values were 620,000 cfd, 0.15 gpm, and 10.5 psig. Daily flows have been as high as 800,000 cfd, and as low as 360,000 cfd, during the last 500 days. On February 4, 1975, after 882 days of degasification, 576 million cubic feet of gas had been removed from the Pittsburgh coalbed; apparently a much larger area of virgin coal is being degasified than is defined by the holes. This study indicates that horizontal boreholes drilled into a coalbed from the bottom of any shaft will effectively remove gas from the Pittsburgh coalbed,

Jan 1, 1975

By R. T. Johansen

A gradual decrease in injection rates commonly occurs as a water-flooding project becomes older. This decrease can be attributed to changes in reservoir conditions, such as swelling of clay minerals, fillup, or gradual plugging of the sand face. However, a rapid decrease in the rate of injection indicates abnormal behavior and is cause for alarm. Extreme plugging conditions can completely stop injections into a formation. Such behavior in wells was the main concern of the tests described in this report. An accepted method of alleviating this condition is by backflowing input wells - closing the supply lines to the wells and allowing the reservoir pressure to force water back into the wellbore and to the surface. If backflowing is not successful, a string of smaller diameter pipe sometimes is run inside the casing, and the sand face is flushed with a waterspray. More drastic treatment is to inject acid into the wellbore to dissolve extraneous matter, or even part of the reservoir material, in an attempt to restore the permeability of the sand immediately around the wellbore. Any of these procedures can he coordinated with bailing and swabbing of the well for cleanout purposes.

Jan 1, 1957

By Ann Hubbs, Vincent Castranova, Jane Y. C. Ma, De-Hwa Chao, Joseph K. H. Ma

AN OVERVIEW OF THE ACTION OF TETRANDRINE ON SILICOSISBecause of the persistent presence of silica dust in the lungs silicosis is a progressive and irreversible disease. At present, there is no proven effective therapy for silicosis. Limited choices of therapeutic intervention with corticosteroids and other immunosuppressive regimens 1,2 have been accepted for some forms of pulmonary fibrosis. These treatments are only minimally effective, and the results provide little understanding of the disease state due to the lack of correlation between drug activity and the mechanism of fibrosis. Thus, continuing effort must be made in the search for effective antifibrotic agents, which may be used to provide a sequential analysis of the fibrotic process and to open the door for further research and clinical development. Tetrandrine is one of hundreds of drugs screened for antifibrotic activity by Chinese scientists. It has been used in China as a treatment for silicosis in open clinical trials3 and in laboratory animals. The action of tetrandrine on pulmonary fibrosis has been attributed to its ability to inhibit particle stimulation of alveolar macrophages, a key cell type central to the fibrotic process, to release oxygen radicals and inflammatory cytokines. Alveolar macrophages (AM) residing on the alveolar wall, are the predominant phagocytic cells of the lungs responsible for pulmonary defense against inhaled microorganisms and other particles and thus play an important role in maintaining the homeostasis of the lungs. 7 Ample evidence suggests that cells of the monocyte-macrophage series play an important role in the immunopathogenesis of pulmonary fibrosis. When upregulated by silica, alveolar macrophages generate reactive oxygen metabolites8·9 which can damage lung parenchyma and release fibrogenic growth factors and cytokines, 10,11 such as interleukin 1 (IL-1), which can induce fibroblast proliferation and collagen synthesis. The cytokine-mediated fibroblast proliferation and collagen synthesis are key steps in the development and progression of pulmonary fibrosis .11 Previous studies by our group have shown that tetrandrine exhibits strong binding affinity to AM and inhibits particle-stimulated respiratory burst activity (oxygen consumption, superoxide anion release, and hydrogen peroxide secretion) in these cells. 13 In addition, studies by Kang et al. 14 have reported that tetrandrine inhibits silica-induced release of fibrogenic factors such as IL-1 which are capable of inducing fibroblast proliferation and collagen synthesis. Reist et al. 15 further suggested that the antifibrotic action of tetrandrine may be mediated in part by the direct effect of this drug on the ability of fibroblasts to respond to proliferative agents. These results indicate that the mechanism of silicosis involves activation of AM and fibroblasts by silica, resulting in abnormal collagen production due to miscommunications between the cell types. Tetrandrine may interrupt this process by direct interaction with the lung cells.

Jan 1, 1998

By Denise A. Herzog

The U.S. Bureau of Mines conducted a study of cyanide leach technology used in Alaska's mineral industry from 1987 through 1990. Literature and cost data were obtained for mines in the contiguous United States, Canada, and Alaska that use cyanide to recover gold and silver. The data was compiled in an effort to evaluate the economics and conditions associated with cyanide use in Alaska. This report discusses heap leaching methodology and evaluates a "typical" heap leach operation in Nevada and compares the results of the Nevada operation to an analogous hypothetical mine in Interior Alaska. Five daily tonnage rates were analyzed for both the Nevada and the Alaska operations to evaluate the spectrum of economic possibilities. The discounted cash flow rate of return (DCFROR) for each production rate was then evaluated in terms of recoverable metal value (RMV). The Nevada RMV for each production rate was then compared with its Alaskan counterpart, and the results averaged. The Alaskan production costs are an average of 1.71 times greater than costs associated with mining in Nevada at a 0% DCFROR. At 15% DCFROR, costs in Alaska are 2.01 times greater than those in Nevada. Costs are higher in Alaska because of the shorter leaching season, increased labor and transportation costs, and heavier precipitation and vegetation.

Jan 1, 1991

By L. C. IlsLey

A list of permissible mine equipment, tested and approved prior to Jan 1, 1937, was published in Bureau of Mines Information Circular 6942 • .ll The present list inc ludes additional equipment approved during the calendar yea r 1937. The ma terial has been listed und er the same. headings as th ose used. in Information Circular 6942. The number that appears at the beginning of each it em represents the number o f this type of ma.chine appr.oved including the machine in questi on; for instance, the miing ma.chine numbered 70 was the seventiet h co al cutting ma chine design for which approval has been isnued. All of the equipment listed represents new designs except that covered by the first item, that is, 57 under the • heading nLoading Machines and Conveyors. 11 This item covers the approval of the 500-volt design of a machine the 250-v olt design of which was approved on January 17, 1935. The system under wich these devices were tested permits the manu-. facturer., after his equipment has passed certain tests prescribed by the 'Ui"eau of Mines, to mark his equipment with a seal showing that it has been approved by the Bureau. These tests are designed to insure t hat equipments hav,e the minimum requirements for safety in use. The only object of the :Bureau in making such tests and publishing lists of permissible equipment is to help decrease the hazards of mining.

Apr 1, 1938

By John W. Frey

This paper is one of a series of digests of foreign mining legislation and court decisions prepared in advance of a general report relative to the rights of American citizens to explore for minerals and to own and operate mines in various foreign countries. This interpretation of the laws of cw Zealand, as prepared by Dr. Frey the best available information in Washington, has been slightly amplified in accordance with suggestions transmitted through the courtesy of the Department of State by W. L. Lowrie, Consul General at Wellington.

Oct 1, 1929

By J. L. Shultz

The investigation of organic compounds in respiratory coal dust by high-resolution mass spectrometry has shown that the organic components differ (1) with particle size, (2) with rank of coal, (3) in coals of same rank from different coal seams, and (4) in respirable mine dust and respirable coal dust (prepared) from the same mine. The eight respirable mine dusts studied are from coal seams in the Appalachian region where the incidence of coal workers' pnumoconiosis is relatively high. The molecular weights of the major organic components vary greatly among these respirable mine dusts; three show strong concentrations of polynuclear aromatic hydrocarbons.

Jan 1, 1972

By P. Kovalchik

The Bureau of Labor Statistics (BLS) classifies hearing loss as a separate illness category. Hearing loss accounted for 11% of all illnesses in 2005 (U.S. Department of Labor Bureau of Labor Statistics, 2006a). According to occupational data for coal mining provided by the Mine Safety and Health Administration (MSHA) from 2000 to 2005, operators that exceeded 100% noise dosage were from only seven types of machines: auger miners, bulldozers, continuous mining machines, front end loaders, roof bolters, shuttle cars (electric) and trucks (Title 30 CFR Part 62, 2000-2005). Roof bolting machine operators rank second among all underground machine operators that exceed 100% noise dose. There are approximately 600 underground coal mines with 3,930 roof bolting machine operators (U.S. Department of Labor, Mine Safety and Health Administration, 2005; U.S. Department of Labor Bureau of Labor Statistics,

Jan 1, 2008

By R. V. Ramani

"In a 1985 seminar, we were told that over-optimism abounds in Artificial Intelligence (AI), that AI is neither a science nor a technology yet, and that we will be both exhilarated and disappointed with AI. In fact, even today, there is no single accepted definition of AI; however, certain features have been identified by AI researchers as essential to consider an entity (e.g. machine or program) to be intelligent. According .to Shank (1987), these features include communication (to be able to communicate with), internal knowledge (knowledge about itself), world knowledge (awareness and knowledge about the world outside), intentionality (knowing what one wants and a plan to seek it, ie. goal seeking behavior), and creativity (being adaptable to changing conditions). None of these figures would individually define intelligence; however, each would be a part of intelligence in its own way.The prospects for the development of entities with AI have never been as good as they are now. The combination of advancements in computer hardware and .software along with new insights into the ways in· which we store knowledge and use it for problem solving has enhanced the potential for the creation ~f intelligent entities. After some unbounded optimism of a major breakthrough in the fifties and frustrating disappointments in the two following decades, it appears now that AI has emerged from research labs to industrial practice. This is confirmed by the growing number of repeat applications of AI in business and industry to the extent that AI can now be considered a technology.AI applications are categorized into several distinct areas such as Natural Language Processing, Speech Recognition and Synthesis, Expert Systems, Robotics, Machine Vision, etc. Of these practical realizations, Expert Systems (ES) has the greatest potential for meeting the decision-making needs of the manager in the ever-growing complex scoio-technical systems. Prof. Feigenbaum, an expert and leader on expert systems, has defined Expert System as"" ... an intelligent computer program that uses knowledge and inference procedures to solve problems that are difficult enough to require significant human expertise for their solution. Knowledge necessary to perform at such a level, plus the inference procedures used, can be thought of as a model of the expertise of the best practitioners of the field."""

Jan 1, 1989

By W. P. Yant

Publication of lists of the devices for giving respiratory protection which have been approved by the U. S. Bureau of Mines is made periodically for the purpose of aiding consumers in procuring equipment .374/ The last published list , approved to March 15 , 1935 , appeared as Information Circular 6845 with the same title as this article . The schedules of requirements and tests which the devices must meet in order to obtain approval are published 2/6/1/8/ by the Bureau of tests the devices must Mines and are available to the public . It is pertinent to mention that the preparation of a schedule of requirements for fresh-air supply devices of the types commonly known as positive -pressure respirators , airline respirators , sand- blast helmets , and hoods , has been practically completed and will soon be ready for release to the public .

Oct 1, 1936

By McHenry Mosier

The application of diamond drills for blast holes is limited to the special Job of extracting floor and stope pillars, and therefore their operation is intermittent. The zinc ore drilled occurs in metamorphosed dolomitic limestone. The mining method is sublevel open-stoping on 200- foot lifts. Ample fresh air is provided by mechanical ventilation. Diamond drilling blast holes began in August 1944. Drills were mount- ed on a 3-inch quarry bar. The contract price for labor for operating equipment owned by the company was $0.23 per foot. The diamond bits were cast-set at the factory in a sintered tungsten matrix. Bit replacement costs were $0.15 to $0.20 per foot drilled. The feet drilled per bit ranged from 87 to 258. The feet drilled per diamond-drill shift ranged from 121 to 129. Holes were loaded with 60-percent special gelatin dyna- mite and fired electrically. In percussion drilling, the estimated feet drilled por machine shift with hand-held sinkers was 65. The tons broken per machine shift averaged 40 throughout the mine. Detachable bits have been adopted recently. The principal advantage of diamond-drilling blast holes at the Balmat mino is the extraction in a safe manner of ore not minable by short-hole drilling. The principal disadvantago is the greater cost per foot of holo in comparison with percussion drilling.

Jun 1, 1947

By George S. Scott

The Bureau of Mines conducted ignition, flammability, and decomposition experiments on gas mixtures containing ethylene to determine its flammability characteristics at elevated pressures and ambient temperatures. Pure ethylene was found to propagate a decomposition reaction at 1,000 psig and ambient temperatures when ignited with 1 gram or more of guncotton in a 2-inch-id bomb. The decomposition products were primarily carbon, methane, and hydrogen.

Jan 1, 1965

By W. C. McBee

Over the past several years the Bureau of Mines has developed a sulfur concrete (SC) technology in which chemically modified sulfur is mixed with suitable mineral aggregates to produce construction materials that are resistant to corrosion by acids and salts. Modified SC materials have been tested in actual operating conditions in 50 corrosive process environments at 40 commercial plants. SC components ranging from small test coupons to 4-ton acid sump tanks were fabricated and installed at plant locations where chemical corrosion was destroying conventional concrete materials. Through cooperative agreements with several companies, floors, retaining walls, and foundations were cast in place us-ing SC materials, then monitored for resistance to corrosion and retention of strength properties.

Jan 1, 1983

By D. B. Starkey

Investigation into the expressions of the field produced by a loop over a conducting half space or in an infinite conducting half space are well documented. Reasonably complex descriptions of the effects of stratification also are reported. However, a model which must contain all of these complexities because of transmission to depths of 15,000 feet and also include the pertibation of the field by a verticle cylindrical steel casing loses its facility in the field or for quick, accurate approximation to field magnitudes and phase. This paper describes the results of two field tests to determine the attenuation and phase versus depth and frequency of an electromagnetic wave (induction field). A simple two-layer model is postulated to predict the magnitude and phase of the induced field which does not require sophisticated computing tools. Correlation of the model with experimental results show agreement of most amplitude measurements to within 3 db and most phase measurements to within five degrees. The tests were conducted in a 7400 foot deep well in Nevada and an 11,000 foot deep well in Wyoming which had conductivities ranging from .0025 mhos/m to .25 mhos/m. The surface transmitting dipole had an area of ~ 10 6 feet squared and constant frequency signals of 1.5 Hz to 20 Hz were transmitted through the earth utilizing less than 65 watts of power. Model Description The magnetic field intensity components generated by a magnetic dipole immersed in an infinite homogeneous medium can be expressed in spherical coordinates as: [ ] where N, I, and (p a ) are the transmitting antenna turns, current, and effective area, respectively, and r is the range from the loops circumference to the measurement point. The case of interest for these experiments, however, is the special case of coaxial dipoles, i.e., ? = 180° . For this case H?= 0 and H reduces to: [ ]

Jan 1, 1973

By K. E. Tame

The Bureau of Mines is studying possible modifications in conventional uranium ore-processing steps to confine and permit controlled disposal of radioactive wastes. Surveys of Ra226 contamination of liquid wastes from uranium mills indicated that the Vanadium Corporation of America plant at Durango, Colo., had one of the more urgent problems. A possible procedure for minimizing the waste disposal problem was to reuse the waste solution in the mill--in effect, erasing the need for disposal of liquid waste. In examining this possibility, interlocked bench-scale leaching and solvent extraction tests simulating the Durango flowsheet were made. The simulated reuse of barren raffinate for leaching and washing was carried through three separate campaigns of 9, 12, and 35 cycles each.

Jan 1, 1961

It was decided to demonstrate the use of latex as a soil sealant by irrigating three small plots at Lanse coded 03A on the west of Brown's run, 3C on the east of the stream, and SB, an area on the spoil bank. Earlier plans to sprinkle latex on twenty acres of the side were abandoned because of easement difficulties. On the basis of results from laboratory soil columns and small plot experiments at Lanse, Naugatex J-3471 was the latex of choice. The irrigation system consisted of plastic pipe (two inch size) for the main line from the water meter to the irrigation area because of lower price and ease of handling. Because the municipal water supply was limited to 20 gpm, low-volume 14V-LA-TNT Rainbow sprinklers were specified with low angle 20° 3/32 inch nozzles to reduce wind effects. At the expected nozzle pressure of 50 psig, each sprinkler covers a 56 foot diameter area at a delivery rate of 1.64 gpm. Each of the three test areas was covered with twelve sprinklers, six used with water alone as a control area and six used with latex and subsequent water spraying. One-quarterturn inlet valves were positioned on the main lines leading to each area. Flow to the treated and untreated areas was set at 10 gpm by Dole flow control valves in the' main entry lateral to each of the six sprinklers. To avoid the use of dilution tanks, a Moyno pump operated by a 1/2 HP, 1140 rpm 5:1 reducing drive was used to deliver 1/2 gpm 48% latex for mixing with 10 gpm water. A 3500 watt gasoline generator provided power for pump and light. Latex was applied at night to take advantage of the lower evaporation and higher humidity. Neutron gauge access tubes were placed in orthogonal arrangement in the areas that were irrigated, with four tubes in the section that were sprinkled with latex and four tubes in the untreated irrigation section in each of the three locations. Each tube, five and one-half feet long and sealed at one end with a plug welded in place, was inserted five feet into the ground in a cored hole. In each irrigation area, the left section of six sprinklers spread the dilute latex while the right section sprinkled the same amount of water to serve as a control plot. As shown in Figure 7 each sprinkler has a 56-foot sprinkling diameter at 50 psig design water pressure. The sprinklers are 30 feet apart on the laterals and 35 feet apart between the laterals. The access tubes (coded AT on Figure 7) were placed in comparable spots on the two sections of each area, so that four soil moisture measurements on the two sections could be compared. Bouyoucos resistance blocks (BB) were also placed in areas 03A and 3C at one, two and three foot depths, but not on the spoil bank area.

Jan 1, 1972