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By R. G. Gürtunca

The future of the United States (US) mining industry will be affected greatly by recent coal mining disasters. These have resulted in new legislation which will have an impact on mining economic costs as well safety and health of miners. This paper discusses the changes that new legislation and regulations are making to the industry and current research that is producing technologies to make mining safer and will likely impact the future of mining.

Jan 1, 2009

By John R. Reeves

The development of an new industry, which must prepare its marketable products at or near the source of the raw material, and ship them to a market which may cover half a nation, is more or less influenced by a number of natural and cultural conditions such as (1) location of plants with respect to a large market, (2) climatic conditions, (3) transportation facilities, (4) labor supply, and (5) water supply. An effort is made in this pager to give in detail a number of the more important of these conditions as they affect, either favorably or unfavorably, the development of the oil-shale resources of southeastern Indiana. The utilization of the New Albany formation for the production of oil will be similar to a large scale low-grade ore proposition in which the raw material can be obtained in very large quantities at a relatively low cost. It appears, therefore, in considering the value of this shale or its economic position in relation to other oil shales, tie cost of mining and preparation for the retort are of prime importance.

Jan 1, 1923

By M. W. Pullen

It is recognized that the determination of electrical resistivity of the earth within a given area may furnish information concerning the location of certain mineralized strata of economic importance. Present knowledge of the electrical resistivity of the various rock formations is almost nil, and the geophysicist who is detailed to make a survey of an area without any data as to the relative resistivity of the underlying rocks is greatly handicapped. Such surveys are usually made within areas known to contain mineral deposits to aid in locating desirable points for drilling. Usually these areas have been prospected by diamond drilling, and drill cores of the various rocks and ores are usually obtainable. Were it possible to make resistivity tests in a laboratory of the drill cores or from pieces of the rocks and ore within an area before attempting a field survey, this would indicate not only the advisability for such a survey but would aid considerably in the interpretation of the results of such a survey. To be of most value a definite method should be used for all such tests, and as yet such a method has not been established.

Jan 1, 1929

This chapter analyses the parameters influencing initial design of communication systems, for new mines and upgrading existing systems. Paragraph 5.2 outlines those variables that must be taken into account during the design stages of a new wired phone system. Recommended features, general requirements, and how they can be implemented are treated in this section. Paragraph 5.3 describes ways of improving or extending the range of trolley carrier phone systems and pager phone systems already installed in the mine. 5.2 New Phone System Design The task of designing an adequate communication, control, and monitoring system for an underground mine must be addressed on a system basis. In addition to insuring that effective voice communication is established, any new system should take into account present and future requirements of remote control and monitoring functions. Chapter 4 illustrated the drastic savings in response time that can be realized when remote control and monitoring are integrated into the overall communication system. The importance of including control and monitoring in the overall design plan for any system cannot be overemphasized. Because each mine is unique, and thus usually has its own special operating characteristics and communication requirements, there is no such thing as "the one best system" to meet the requirements of all mines. The optimum communication, control, and monitoring system for a mine must be one that has been tailored to meet the special requirements of that particular mine. Factors that must be considered during system design include- a. Type of mine and mining methods (low- or high-seam coal, deep hardrock mine, stope caving, longwall, room and pillar, etc.). b. Maximum number of working sections. c. Expected mine growth rate and eventual maximum size. d. Haulage methods (tracked trolley, diesel, belt, etc.). e. Underground power distribution system (dc, ac, or both). f. Features desired (two-way radio paging, private line capability for emergency use, etc.). g. Redundant or backup systems for use during outages of the normal system. Although no two mines are alike, the following items have been established as the main characteristics desired for any underground communication system: 1. Multiple Communication Paths to Outside--the objective here is to give all telephones a second method of communicating with the surface. 2. Audible Emergency Signaling--the communication system provides the main means of alerting miners during emergencies. The system should include means to broadcast distinct audible signals for emergency signaling. Initiation of these signals should probably be controlled from. a central outside point, such as a surface control room. 3. Emergency Override--provisions should be included to permit any conversation to be overridden with emergency communication. 4. Selective Area Page--as mines grow larger it is apparent that the entire telephone system paging mode need not be activated each time a call is initiated. When the general area of a

Jan 1, 1984

By Walter K. Utt

The vibration levels of the heavy machines used in surface mining are much greater than for vehicles used on highways. In order to assure the proper functioning of electronic equipment placed on the surface mining vehicles, the U.S. Bureau of Mines has conducted a program of field measurements to define their vibration environment. The information in this report is for a class of vehicle that has a blade for scraping and wheels with rubber tires. The statistical information derived from these measurements can be used as a basis for laboratory testing to qualify equipment for a surface mining vehicle of this class. The envelope that would encompass 99 pct of the vibrations encountered in normal operations is presented for each location on the vehicle. The five locations for which data were recorded are the floor of the cab, the engine, the frame, the drive train (gear, differential, and torque converter), and the axle. Tabulated data are provided for those who wish to use a different probability level. The appropriate test profile for the laboratory testing can be determined from the information presented in this report.

Jan 1, 1993

By T. H. Dubaniewicz

Fiber-optic technology is progressing rapidly, including the development of fiber-optic sensors for many applications. These sensors have the advantages of high sensitivity, light weight, small size, high bandwidth, and freedom from electromagnetic influences. The U.S. Bureau of Mines is investigating the use of fiber-optic technology to monitor mine atmospheres. This report describes a methane monitor based on differential absorption of infrared light. The monitor can detect methane concentrations as low as 0.2 vol pct as far away as 2 km via fiber-optic cable. The upper range is 100 vol pct methane. Since the system requires no electrical power within the mine, it is intrinsically safe.

Jan 1, 2010

By R. E. Lindstrom

A study of ion-exchange resin crosslinkage and eluant flow rate, resin-bed shape, and addition of separating ions to feed stock was undertaken to determine their effect on the separation efficiency of ion-exchange on bastna-site-rare-earth elements. Results show that 12-percent divinylbenzene (DVB) crosslinkage resin is detrimental to separation efficiency at flow rates over 2 to 5 ml./min./sq. cm.; whereas, separation with 4-percent DVB crosslinkage resin is relatively unaffected by flow rates between 2 and 10 m1./min./sq.cm.

Jan 1, 1959

By M. M. Fine

This report describes a Bureau of Mines technical feasibility study of simultaneous reduction and induration of pelletized iron ore to make a product with superior qualities as blast-furnace feed. Highly reduced, physically competent pellets can be made from magnetite and specularite concentrates that contain small additions of bentonite as binder. In batch tests, pellets were dried, surrounded with solid fuel in crucibles, and heated to the reducing temperature. Total iron content of the best products was higher than 80 percent and crushing strength of 1/2-inch metallized pellets ranged up to 600 pounds or more. Comparative tests of several commercial oxide pellets showed a wide range in crushing strengths, but most values were less than 350 pounds. Continuous tests in a rotary kiln resulted in the same degree of reduction, but the pellets had lower crushing strengths because of the limitations in the maximum operating temperature of the small kiln.

Jan 1, 1962

By D. Harrington, F. E. Cash

For a number of years the efforts of the coal -mining industry , as well as of the Bureau of Mines , have been directed largely towards the limitation and prevention of explosions in coal mines . The origin of most explosions is ignition of methane or marsh gas , but the extent and violence of these explosions depend chiefly on the combustible dust present . The Bureau of Mines has conducted a large number of tests on the use of incombustible materials in limiting or preventing widespread explosions . The result of these tests , published in Bulletins 167 and 268 and Technical Paper 386 , proves that incombustible dust can be so applied and maintained in coal mines that the ignition of the mixture of incombustible and combustible dusts , or the propagation of flame by the dust mixture , is impossible ; on the other hand , experience and experiment indicate that watering methods are not reliable as a preventive of general or widespread coal-mine explosions . This report describes the use of " mudite , " a mixture of water and finely divided incombustible soil or dirt applied in some coal mines as a means of attempting to limit or prevent widespread explosions .

Jan 1, 1929

By James R. Coldwell

Mining and processing cost analyses were conducted by the U.S. Bureau of Mines on massive sulfide copper-zinc and low sulfide vein gold deposit types that may be found in the Ketchikan Mining District. Reserves and recoverable metal values (RMV) needed to make these deposits economically viable were modeled. Methods for estimating ore grades and required RMV are presented. Economic modeling for massive sulfide deposits indicated the RMV necessary for a 15% Discounted Cash-Flow Rate-Of-Return (DCFROR) for an underground cut-and-fill mine ranged from $137/mt for a 6,100 mtpd on-site milling operation to $526/mt for a 450 mtpd off-site milling operation. On-site milling was always less costly than off-site milling. Economic modeling for low sulfide vein gold deposits indicated the RMV necessary for a 15% DCFROR for an open-pit mine, off-site mining operation ranged from $S4/mt at 2,900 mtpd to $71/mt at 360 mtpd, and from $49/mt at 2,900 mtpd to $100/mt at 360 mtpd for an on-site milling operation. Off-site milling was less costly than on-site milling until production exceeded approximately 1,700 mtpd. Then, economies of scale reduced operating costs enough to offset the higher capital costs required for on-site milling.

Jan 1, 1995

By BUREAU OF MINES

In 1948 the United States became a net importer of oil. Coupled with an unpre- cedented domestic production of 5,900,000 barrels daily, imports approximating 500,000 barrels made available a total supply of 6,400,000 barrels a day. Thus, by herculean effort, the oil industry was able to meet an extraordinary demand at home and, in addition, to ship abroad almost 400,00 barrels daily of petroleum and products. The country's oil position now differs greatly from that prevailing at the be- ginning of World War II. Then, actual oil production averaged about 4 million bar- rels a day, and productive capacity probably was greater than 5 million barrels a day. As the demand of the military and industrial machine grew with the rising tempo of the drive toward victory, the United States not only met its own needs but pro- duced about two-thirds of the total oil requirements of the Allied Nations, excluding Russia. As a people, we can be deeply grateful that the Nation's petroleum resources were adequate and sufficiently developed to support such a tremendous effort. Even in those critical hours when immediate needs were the paramount issues, a prudent Congress paused to contemplate the importance of an assured long-term supply of liquid fuels. From these deliberations came the Synthetic Liquid Fuels Act of 1944, which authorized research and development work on new sources of oil coal, oil shale, and agricultural and forestry products. ce World War II, a civilian demand for 6 million barrels of petroleum prod- ucts has become the order of the day every day. By drilling as many as 39,000 new wells a year, the production rate has been increased enough to meet domestic require- ments by a bare margin. Some imports were necessary, however, to fill both domestic and foreign demands, and these doubtless will increase. Is this policy of exploration within the United States and the development of oil in foreign countries adequate insurance for the fulfillment of our future national needs? This question has two aspects one purely civilian and economic in character and the other significant from the standpoint of our national defense. There are now approximately 4,000 producing oil fields in this country. At first thought, it would appear that production could decline in a considerable number of these fields without materially affecting the over-all daily output. However, 48 percent of the oil comes from only 111 major fields which contain 50 percent of the total proved domestic reserves. It is apparent, then, that the flow from large fields - having proved reserves of 100 million barrels or more each must be sustained if daily production is to be kept at the present levels. Essentially, this means that new major fields must be discovered about as rapidly or perhaps more rapidly than the older ones lose productive capacity. From 1940 through 1947, only eight major fields with estimated reserves of more than 100 million barrels each, were discovered and proved - an average of one such field a year. The total estimated reserve of these eight fields was less than 1 year's supply at the present rate of use. As drilling continues, some existing fields ultimately will prove reserves larger than those now known. Without a pronounced increase in the num- ber of major discoveries, however, the prospects for increasing our present productive level are not encouraging. Any gap that appears between domestic productive capacity and demand could be filled with supplies from proved oil resources abroad. Assuming cheap pipe-line and tanker transportation to the United States, freedom from exorbitant taxes and charges

Jan 1, 1949

By Potter G. M.

Ore-dressing tests were conducted on a sample of ore submitted by the Richmond Hill Mining Co. of Lead, S. Dak. as a part of the Bureau of Mines program for investigating potential domestic sources of manganese. Half of the sample was taken from the 300-foot level and half from surface cuts. The problems involved were liberation and rejection of silica and iron and removal of lead, Silver, and gold from the manganese concentrates. Although a portion of the silica and iron oxides was too intimately associated with manganese minerals for rejection by ore-dressing methods, thus limiting recovery of high-grade concentrates, the Richmond Hill ore was found amenable to simple gravity methods of concentration for producing intermediate-grade products. By jigging and tabling, 73.8 percent of the total manganese was recovered in a product that, when sintered, assayed plus 40 percent Mn. Lead, silver, and gold were successfully removed from gravity concentrates by a chloridizing roasting treatment.

Jan 1, 1948

By Paul M. Tyler

The enormous deposits of greensand in New Jersey and elsewhere in the United States, many of them close to important octant industrial centers, constitute a perpetual challenge for research chemists to convert them into a commercial asset of national importance. Following the introduction of more concentrated fertilizers, comprising synthetic mixtures of more soluble salts, the quantity of greensand used directly upon the soil has diminished, but deposits of such material still have at least potential value locally for use not only as fertilizer but also as a water softener. An annotated bibliography of the already extensive Literature on greensand, virtually complete to about the end of 1929, has been issued by the Bureau of Mines3/, and the commercial aspects as well as the technology of greensand utilization are discussed in available publications, The purpose of the present circular, therefore, is merely to provide a brief outline of certain general essential considerations for use in appraising the potential value of a greensand deposit in any given locality.

Jan 1, 1934

By J. J. Drost

The feasibility of basic oxygen furnace (BOF) offgas heat recuperation by preheating scrap was investigated on a pilot plant scale by the Bureau of Mines. In this study, offgases generated during the oxygen blowing of a molten pig iron and scrap charge were passed through a static bed of shredded auto scrap. Scrap quantities varying from 100 to 180 pounds and representing from 22 to 40 percent of the 450-pound BOF metallic charge were preheated in this manner. Average scrap bed temperatures of 1,650° F for 100 pounds of scrap and 1,150° F for 180 pounds of scrap have been achieved during the blows. As compared to cold scrap used in the normal BOF practice, it was found that by preheating scrap, usage could be increased by 43 percent. The thermal energy recovered by this preheating method can account for up to 44 percent of the energy necessary to melt the scrap.

Jan 1, 1974

By J. H. Wiggins

"The tests described below were conducted by the Bureau of Mines at a lease in Oklahoma on installations designed to decrease evaporation losses of crude oil Pram storage tanks. Use of the lease was granted by the Oklahoma Producing and Refining Corporation of America. Tankage was obtained through the courtesy of the Parkensburg Pig and Reel Co. The purpose of the installations and tests was to demonstrate the value of making crude-oil storage tanks gas-tight, rather than to determine the amount of evaporation in any one type of tank. None of the tanks used were absolutely gas-tight, but one of them was very nearly so. They comprised a tank of the ordinary open type with an 18-inch manhole, a tank with a ""4-inch vent"", a tank with a ""smaller vent"", and a tank which had only ""pin holes"" through which air and vapor could pass freely. On the last two tanks any excess pressure was taken care of by an automatic differential pressure regulator.The results obtained in these tests indicate that tight tankage will soon pay for itself. They will not, however, serve as a basis on which a producer can compute the actual number of days necessary for tight tankage to pay out, because the oil used was exceptionally volatile. It is probable that the average evaporation loss in the Mid-Continent field is at least one-half as great as that shown by these tests, and if this is true, the saving that would be effected by providing tight tankage on the lease will undoubtedly justify the expense. The installation of evaporation-proof tanks on the lease has been delayed by the failure of production managers to realize, first, that their evaporation losses are enormous, and, second, that they can practically eliminate these losses by a simple and inexpensive installation."

Apr 1, 1921

By David C. Byrne

PURPOSE: Evaluate practical technological advances in hearing protective devices for use in different mining environments. RESEARCH SUMMARY: Previous NIOSH research shows that miners develop hearing loss much more quickly than nonoccupationally noise-exposed individuals. Also, miners experience a greater severity of hearing loss than would be expected for nonoccupational noise-exposed persons of the same age and sex. As described in the National Occupational Research Agenda, problems created by occupational hearing loss include (1) the reduced quality of life due to social isolation and unrelenting tinnitus, (2) impaired communication with family members, the public, and coworkers,(3) a diminished ability to monitor the work environment (e.g., warning signals, equipment sounds, etc.), (4) lost productivity and increased accidents resulting from impaired communication and isolation, and (5) expenses for workers’ compensation and hearing aids. Although the elimination of hazardous noise is the ideal long-term solution to the noise problem, miners will likely need to rely on personal hearing protection in certain situations for quite some time. However, it is well known that noise attenuation provided by hearing protectors as they are worn during everyday use in the workplace is usually worse than when tested under laboratory conditions. Additionally, workers may refuse to wear their hearing protection for any number of reasons. Therefore, this project was initiated to evaluate practical technological advances in hearing protectors, with an emphasis toward optimizing the balance between effectiveness, comfort, overprotection, and communication ability. Currently, the necessary in-house laboratory facilities and research techniques are being finalized. Individual experiments are planned that involve analysis of new hearing protector technology under both laboratory and field conditions. The laboratory components are to consist of con-trolled studies using human subjects and/or an anthropometrically correct artificial test fixture to evaluate the adequacy/effectiveness of various hearing protective devices. Field studies are planned to determine the actual usefulness and practicality of the hearing protectors as used in diferent mining environments. Recommendations can then be offered to the mining community regarding correct earplug/earmuff usage that maximizes recognition of hazard/warning sounds while adequately protecting the miners’ hearing.

Jan 12, 2000

By M. H. Kline

The Chestatee mine is one of several well known pyrite deposits in Georgia that are reputed to carry appreciable quantities of copper with the ore. The deposit is? in Lumpkin County on the Chestatee River, 6 miles northeast of Dahlonega (fig. 1). Old records and reports indicated the probable existence of an extensive unmined ore body, but the mine is inaccessible at present. The Bureau of Mines, after studying old maps and records, decided to cor8-drill along the strike of the lense beyond the limits of the indicated old workings in an attempt to extend the possible reserves. The advantageous location of the property indicates that it could become an economic source of pyrite to be used for the manufacture of sulfuric acid. Iron sinter resulting from the roasting of the ores could be sold at a premium in the Birmingham, Ala., area, and the copper content could be extracted to help replace the nation's depleted resources of this metal.

Jan 1, 1949

By Michael S. Miller

The Carson-Iceberg RARE II study area, consisting o; 209,990 acres (134,983 ha), is on the crest of the Sierra Nevada in California, about 35 mi (56 km) south of Lake Tahoe. The area is divided into four parts: C4-986; C5-986; and B5-986, north and south portions. No mineral production has been recorded for the area. However, gold, silver, and tungsten resources and potential for additional resources have been estimated for the area and just north of area C4-986.

Jan 1, 1981

By H. C. Ko

Calorimetric determinations of low-temperature heat capacities and the standard enthalpy of formation were made by the Bureau of Mines for aluminum sulfide, A12S3. The standard entropy (S°), enthalpy of formation (?Hf°), and calculated Gibbs energy of formation (?Gf°) at 298.15 K are 27.93±0.05 call deg-mole, -155.6±0.9 kcal/mole, and -153.0±1.0 kcal/mole, respectively.

Jan 1, 1976

By Steven J. Page, William A. Heitbrink, Andrew B. Cecala, Edward D. Thimons, John A. Organiscak

Miners at noncoal surface mining operations are often exposed to high levels of respirable dust. In an effort to lower the respirable dust exposure of these surface miners, the National Institute for Occupational Safety and Health (NIOSH) has been conducting research to address this problem in a practical and economically viable manner. One successful effort deals with lowering the dust exposure of equipment operators in enclosed cabs. Many types of surface mining equipment utilize enclosed cabs to protect equipment operators from dust exposure. Normally when the equipment is new, the cabs are fairly airtight. These tightly sealed cabs, combined with good filtration systems, generally provide the operator with good dust protection. However, most mining equipment is older, and as aging occurs, many components of the enclosure deteriorate. The structural integrity of the cab diminishes and the effectiveness of the air filtration system fails. NIOSH has been successfully researching costs-effective methods to improve both filtration effectiveness and cab integrity of these older cabs in order to provide a healthier work environment for equipment operators. Dust sampling records indicate that drill operators and helpers have the highest dust exposure of all workers at surface mining operations. Since much of the overburden contains a high percentage of silica, the health hazard associated with this dust can be even more serious. NIOSH research is addressing techniques to lower respirable dust levels at surface drilling operations. INTRODUCTION NIOSH's mission is to assure a safe and healthy work environment for the working men and women of this nation. The primary emphasis of NIOSH's Pittsburgh Research Laboratory (PRL) is mining health and safety research. This report focuses on two areas of research