Search Documents

By Allen D. Look, Alan A. Sharp

"INTRODUCTION The bottoming of the United Verde sulfide pipe has shortened the expected life of the United Verde mine to a matter of a few years. First located in 1876, this Arizona mine has had a long period of activity, having reached a peak production in 1929 of over 71,000 trans of copper. Through these many years of successful operation, a safety program has evolved in keeping with the proficiency developed in mining the ore body. It is the purpose of this paper to record the safety practices in effect at this mine so that others may have the benefit of lessons ,learned through experience 'and years of work toward an improved accident record.ACKNOWLEDGEMENTSAcknowledgment 'is 'made to ,the Phelps Dodge Corp. for its cooperation in making available data contained in this paper, and to C. E. Mills, general superintendent; W. W. Little, mine superintendent; John Riordan, employment agent; and G. S. Leisk, safety engineer, for their helpful suggestions and information furnished.GENERAL INFORMATIONThe United Verde copper mine is situated just west of Jerome, Ariz., at an altitude of approximately 5,500 feet. Purchased by the Phelps Dodge Corp. in 1935, the mine employs approximately 500 men - 385 underground and 115 on the surface."

May 1, 1949

By Earl W. Waay

"Since the beginning of the petroleum industry in 1839, up to within two or three years ago, these has been a dearch of engineers who have had the fundamental technical training also sufficient practical experience so that they could compete with practical men. Need for Technical Investigations in Industry: As in the early stages of the mining industry, the petroleum industry has been rather slow in realizing the need for technical assistance and investigators in the development and production of oil lands. The rapid increase in consumption, however, during the past few years has accentuated this need more than anything else could have done. When it is realized that our production cannot longer keep pace with the demand, it is easily understood why it is imperative that be instituted which will tend to conserve and prolong the supply of oil from the fields now known. It is interesting to note from preliminary production figure given cut by the U. S. Geological Survey, for the year 1919, that the United States produced about 430,000,000 barrels, an increase of 22,000,000 or 6 per cent over 1918 production and also there was imported, chiefly from Mexico, a little over 52,000,000 barrels, making a total of 430,000,000 barrels, to satisfy the trade demand in the United States of which almost 6,000,000 barrels was exported. Stocks were not materially increased.Other significant facts regarding our petroleum industry, are that just recently the U. S. Shipping Board in soliciting bids for 24,000,000 barrels of fad oil to meet prospective needs, received bids for only 1,500,000 barrels at prizes ranging from 75 to 90 per cent higher than was paid last year. One large company on the Pacific Coast has stopped its export trade, and has notified consumers,of gas-engine distillate that they will no longer make deliveries of this product. This will materially affect the farmer, in many instances, through his use of the truck and tractor."

Apr 1, 1920

By Arne Landsberg

The Bureau of Mines has undertaken research to elucidate the chemistry involved in the efficient recovery and control of minor elements in base metal smelting operations. These elements should be effectively recovered not only because they have commercial value, but also because of their potential hazard to workers' health and the environment, if they are not controlled during processing. Cadmium, a minor metal in zinc ores, is the subject of this report. The roasting step of the complex zinc-smelting process was chosen for investigation because of the high potential for removing cadmium by volatilization during this primary stage. Commercial roaster feed materials were used to determine the sequence of reactions and the effect of these reactions on the volatilization of cadmium. Electron microprobe examination of both the commercial roaster product and oxidized sulfide solid solutions prepared in the laboratory showed that oxidized iron was of prime importance in preventing cadmium volatilization. The mechanism by which iron prevents cadmium volatilization is proposed, and a preheating technique is recommended for more effectively recovering cadmium prior to roasting.

Jan 1, 1981

By Charles Vaught, Henry J. Kellner, Michael J. Brnich, Henry P. Cole, William J. Wiehagen

In 1985, U.S. Bureau of Mines and University of Kentucky researchers began a series of studies relating to self-contained self-rescuer (SCSR) donning proficiency. During the next 5 years investigators examined a number of factors that have a bearing upon miners' ability to put on and use the apparatus in an emergency: the procedure being taught; availability and utilization of training models; opportunities to practice; hygiene; and on-the-job training. This report presents an overview of that research. It is concluded that companies should adopt a hands-on training protocol that allows them to integrate SCSR donning practice into other workplace routines such as fire drills.

Jan 1, 1993

By J. H. Tylczak

The Bureau of Mines studied the effect of alloy additions on abrasive wear of low-alloy steels. A dry-sand, rubber-wheel abrasion test appa-ratus using ASTM G65-Sl procedure B was used for the abrasive wear tests. Eighty-six material heat-treatment combinations were abrasion tested. Results of these tests were analyzed statistically using regression analysis to see if additions of Cr, Mn, Mo, Ni, Si, AI, Cu, and S were significant in affecting the abrasive wear rate of low-alloy steels. Regression analysis was also used to confirm hardness and C affect on the abrasive wear rate of these steels. It was found that for all the steels taken as a group, increased amounts of Mn significantly reduced the wear rate, while increased amounts of Mo and S1 increased the wear rate. Analysis also confirmed previous research done by others, that increasing hardness and amounts of C reduced the wear rate. For the hardened steels taken as a class, only increasing amounts of C and Mn reduced the wear rate, while increases in Si increased the wear rate. In the class of unhardened steels, increases in C, Mn, and S re-duced the wear rate, whereas increases in Mo increased the wear rate. The steels with the best resistance to wear were two hardened experimen-tal steels similar to AISI 1055 and AISI 107S.

Jan 1, 1986

By M. M. Tilman

The Bureau of Mines evaluated corrosion resistance of Split Set friction rock stabilizer mine roof bolts to aid in better prediction of useful service life. Electrochemical corrosion testing was conducted utilizing an automated corrosion measurement system. Natural and/or synthetic mine waters from four uranium and two copper mines were the test media for the two types of high-strength, low-alloy (HSLA) steels from which Split Set stabilizers are manufactured, and for galvanized steel. Tests were conducted with waters of minimum and maximum dissolved oxygen content at in-mine water temperatures. Retrieved Split Set stabilizers were also evaluated for property changes. Galvanized steel was found to be far superior to the unprotected steel in general corrosion resistance; limited tests indicate little ten.dency to pitting, contrary to behavior for the uncoated steel. Copper-bearing HSLA steel was slightly more corrosion resistant than non-copper-bearing HSLA steel. Statistical analyses resulted in development of equations relating dissolved oxygen, chloride, sulfate, and magnesium contents of mine waters to corrosion rates of the two HSLA steels (nongalvanized). An equation was developed that relates corrosion rates of galvanized steel to mine water temperature and dissolved oxygen content. Variable conditions in mine environments make corrosion damage difficult to predict and emphasize the need for corrosion prevention and control.

Jan 1, 1984

By Charles F. Jackson

Waste filling has been employed for many years for supporting the walls of stopes and preventing failure and subsidence of the surrounding and overlying rock formations, and its effectiveness for this purpose has long been recognized. It is used for permanent support in ground where timbering (including square-setting) is inadequate for more than temporarily supporting the walls of the excavations. It should be rioted, however, that effective as a good, solid fill may be in resisting heavy side pressure and direct weight, its usefulness for supporting large areas of back and preventing breaking and movement of the overlying rocks is limited. Even the strongest and most uniform rocks will break if the unsupported span becomes too great; and since filling cannot be packed tightly against a horizontal back there is always a possibility of the back breaking and consequent subsidence if the maximum self-supporting span is exceeded. Planes of separation, such as bedding and fault planes, slips, and joints, are common in all rock masses; these may occur above the stoping area where their presence cannot be ascertained by observation. If too much reliance is placed upon filling for the support of a large horizontal area of back (as contrasted to support of vertical or steeply inclined walls) large masses of rock may break along a. plane of weakness, compress the fill, and leave an open space into which caving of the overlying rocks may continue until the space is filled. In this paper the term "waste filling" includes any filling material other than ore - waste mine rock, rock from surface quarries or opencuts, sand and gravel, mill sands, or slags from smelting operations.

Jan 1, 1935

By David Schlain, C. B. Kenahan, F. X. McCawley

The electrodeposition of protective coatings of tungsten from a sodium and lithium borate - tungstate - tungstic oxide fused salt electrolyte was investigated . Soluble tungsten anodes were employed . Deposits were made on molybdenum , Carpenter 20 stainless steel , Inconel , and nickel . An atmosphere of argon was maintained around the electrolytic cell , and the electrolyte was stirred by rotating the cathode . Thick deposits of tungsten (up to 26 mils ) were made at a temperature of 900 ° C and cathode current densities of 0.3 to 0.4 ampere per square inch with high current efficiencies . The effects of variations in temperature , current density , electrolyte agitation , and tungstic oxide content of the electrolyte and of the presence of impurities such as moisture , air , iron , and nickel were investigated .

Jan 1, 1964

By K. K. Kelley

"INTRODUCTION The Bureau of Mines nitrogen peroxide process (2) 3/ for extracting manganese from low-grade ores is essentially a two-stage process involving the reversible reactionMnO2 + 2NO2 + 6H2O = Mn (NO3)2 . 6H2O (1).At lower temperatures this reaction proceeds to the rigth and affords a means of dissolving manganece and separating it from unreacted ore. At higher temperatures the reaction proceeds to the left and manganese dioxide is recovered and nitrogen peroxide regenerated for recycling. Evidently, therefore, the energy required for decomposition of manganous nitrate is a matter of practical importance. Similar information for certain other nitrates also is desirable beceuse the nitration step of the process produces appreciable amounts of nitrates of other metals, such as iron, aluminum, magnesium, calcium, and barium, some of which are not broken down in the evaporation and decomposition steps. Thus, a portion of the nitrogen peroxide is not directly available for recycling. Whether or not it is feasible to recover nitrogen peroxide locked in the more-stable nitrates depends partly on the energy required and the conditions necessary for their decomposition.To supply information bearing directly on these subjects, several researches were undertaken at the Pacific Experiment Station: (a) Heats of formation (24, 25, 26) of nitrates of manganese, magnesium, calcium, barium, and aluminum were measured at 298.2° K:; (b) low-temperature specific heats (23), in the range 51° to 298.2° K,, and entropies of nitrates of magnesium, calcium, barium, and aluminumm were determined; and (c) heat contents (21) above 298.2° K. of the nitrates of manganese, magnesium, calcium., and barium were measured. The results of these studies, when correlated by thermodymamic methods, permit evaluation, at any temperature of interest, of the energies required to decomposethe nitrates and furnish information concerning the equilibrium pressure temperature relationships."

Sep 1, 1944

By RUDULF KUDLICH

Pennsylvania anthracite coal is almost universally recognized to be the solid fuel best suited for domestic use when cleanliness , convenience and cost are considered . At various times and in various localities , however, conditions so affect the supply that it becomes insufficient or is too high in price and recourse must be had to other fuels as substitutes . In practically every district in the United States where anthracite has been the common domestic fuel , some other fuel is available as a substitute . In even the most severe climates such fuels are used either as emergency substitutes for anthracite , or as the ordinary domestic fuel . There may be some drawback to the use of such fuel , such as the need of more frequent attention to the furnace , smoke , soot and dust , in the case of solid fuels lower in price than anthracite , but these inconveniences must be accepted as necessary accompaniments to a decreased fuel bill . The cleanliness and ease of handling anthracite in the house must be considered in the light of a luxury and a higher cost of heating with this fuel must be expected . That a growing number of people are willing to pay for such added convenience is evident from the increasing mumber of heating installations using oil , gas and electricity , all of which are more convenient and usually more expensive even than anthracite .

Aug 1, 1923

By P. A. Lawless

The objective of the research performed A for the Bureau of Mines on this contract was to develop a portable instrument for the detection of carbon monoxide (CO) in a mine environment. The desired characteristics were sensitivity and specificity for CO with a stable calibration. The sensor of the instrument was to be of metal oxide composition, requiring low power for compatibility with the types of batteries presently used in personal equipment in mines. The solid state design was also desired for ruggedness and small size. A key design feature of the instrument was to be provided by adherence to the intrinsic safety design requirements for electrical equipments operated in potentially exposive mine atmosphere. The Research Triangle Institute has prior experience in developing a solid state oxygen sensor using a thin film of zinc-oxide (Ref. 1) and experience in fabricating thin film devices. Solid state sensors utilized by other workers (Refs. 2, 3, 4, 5, 6) have included metal and semiconductor films and crystals of materials like carbon and aluminum oxide for the measurement of water vapor in the air and have relied upon measuring resistance and capacitance changes in the sensor in response to adsorbed vapors or gases. Since the effect of carbon monoxide in changing the resistance of various materials such as molybdenum, platinum, and zinc oxide had been reported (Refs. 7, 8, 9, 10), the requirements appeared to be realisable, although it was recognized even at the inception of the work that specificity to carbon monoxide might require the incorporation of more than one sensor.

Jan 1, 1976

By R. W. Dougherty

From time to time interest has been evidenced in transporting coal with water in pipe lines. About the year 1895, United States patents broadly covering a method of pumping coal with water through pipelines were granted to W. C. Andrews. His process was used to some extent in pumping anthracite culm and waste back into the worked-out portions of the mines. About 1905, W. T. Donnely was granted patents relating to pumping anthracite silt away from the breakers. From about 1913 until 1924, a British engineer, Gilbert G. Bell, used a short pipeline to convey coal with water from barges on the Thames River to the Hammersmith Electricity Generating Station, London. Minus 5-inch coal was transferred 660 yards through an 8-inch pipe. Some trouble was experienced with fine coal, which tended to plug the line. Bell made several proposals to transport coal by pipeline overland from the Midlands to London, a distance of about 100 miles, but these were never adopted. This survey is concerned mainly with the problems presented by actual pipeline transportation of coal with water. It is assumed that the coal will have been processed to remove most of the abrasive impurities by conventional methods prior to introduction into the line, and that it has been crushed to the required top size. Dewatering at the discharge end of the line is considered part of the conventional cleaning process. There still remain many pump-performance and behavior of water-coal mixture problems that can be solved only by actual performance tests. It is recognized that the distribution of coal to other than very large users is not changed. Large storage areas would be required to supply seasonal markets. Large users, such as power plants and heavy industries, could be supplied by branch lines directly to the point of use, It is also recognized that pipe lines might not be able to carry a full range of sized coal to meet market demands in many areas.

Jan 1, 1951

By A. Gene Collins, Cynthia A. Pearson, Cathy J. Waters

The chemistry of selenium and tellurium is discussed , along with a method of preparing a synthetic oilfield brine , an oilfield brine sampling method , and methods for determining selenium and tellurium in complex oilfield brines . Selenium either can be reduced to the elemental form with sulfur dioxide and determined semiquantitatively by color comparison of the red amorphous form or can be converted to selenite and determined quantitatively by reacting it with 3,3 ' - diaminobenzidine and obtaining its spectral absorbance at 420 mu . Tellurium can be reduced to the elemental form with hypophosphorous acid , and the spectral absorbance of its red hydrosol can be measured at 400 mu . Less than 0.05 mg / 1 of selenium and 0.1 mg / 1 of tellurium can be determined by the described methods .

Jan 1, 1964

By G. R. Hopkins, E. W. COCHRANE

The number of completed petroleum refineries in the United States continued to decline in 1937 , but the total capacity to process crude oil continued to increase . These facts were ascertained in the Bureau's annual canvass of refinery capacity as of January 1 , 1938 . Several important changes were made in the census questionnaire for January 1 , 1938 . First , the basis of reckoning cracking capacity was changed from cracking stock charged to cracked gasoline produced . Although this is a definite improvement , in that it is no longer necessary to consider the yield , it is unfortunate that the data for January 1 , 1938 cannot be compared with cracking - capacity statistics since 1925. Other changes or additions included separating capacity at operating plants into that actually operating and that closed down ; collecting data on capacity added or retired during the previous year ; breaking down idle capacity according to physical status ; and separating new capacity into that built for replacement and that built to augment existing capacity . Prior to January 1 , 1938 , the total capacity of an operating plant was listed as " operating " even though some stills might have been closed down ; furthermore , the only capacity reported as being under construction was that of new plants that were being built on January 1. To make the statistics clear , the totals for the United States as of January 1 , 1938 , are given on both the old and the new bases . On January 1 , 1938 , there were 551 completed plants compared with 572 the previous year . Ten new plants were under construction on that date compared with 11 the year before . The greatest number of completed plants recorded was 632 on January 1 , 1936 ; since then , competitive conditions , particularly in the East Texas field , have been instrumental in reducing the number of small independent plants . The total crude- oil capacity of the completed refineries on January 1 , 1938 , was 4,351,151 barrels , of which 3,970 , 196 barrels ( 91 percent ) represented the capacity in actual operation and 380,955 barrels ( 9 percent ) was shut down . The " shut -down " capacity ( 199,875 barrels on the old basis ) was the lowest since pre- depression days , chiefly because numerous idle East Texas plants were removed from the list . The new method of compiling the statistics sheds considerable light on excess crudeoil capacity , which has been the subject of considerable speculation in recent years . The highest daily average crude runs to stills reached in this country was about 3,460,000 barrels in September 1937. At that time , the total crude - oil capacity was about 3,925,000 barrels . This indicates that at peak operation the excess capacity was somewhat less than

Aug 1, 1938

By M. A. Elliott

Diesel-powered haulage equipment has recently been tested and approved for permissibility by the Bureau of Mines for use in mining in the United States. Achievement of this advance in safety involved extensive studies, both in the testing station (2, 3, 20, 21, 22, 23, 24, 25, 26, 27)3/ and in the field 1, 4, 13, 30), of the operating characteristics of diesel engines in relation to the toe of such engines underground. The results of these studies formed the basis for establishing the requirements that should be met by diesel-powered haulage equipment approved for permissibility. Considerable interest has been manifested in the development of diesel-powered haulage equipment fur mines. The purpose of this paper is to retrace briefly the course of this development and to answer such questions as: What is the history of the use of diesel engines underground? Why has the Bureau of Mines been interested in the development of diesel-powered haulage equipment for use in mines?

Jan 1, 1953

By W. H. Coghill, F. D. DeVaney

"Introduction Numerous investigators have studied grinding. Each has contributed his bit to a literature that is difficult to correlate. Too many of the results have been transformed into curves with no many ""inflection points"" and ""counterflexures"" that they obscure the issue.Some of the investigators have neglected the very essence of the problem, namely, the power and the amount of material to which a known amount of work was applied. The purpose of this paper is to show the ease with which results can be interpreted when these quantities are duly recognized. Some grinding tests will be given for illustration.Grinding studies are of two kinds: (1) Study of the character of the ore and (2) study of the performance of the machines. Several ores may be crushed by a given machine, or several machines may be used on a given ore. The illustrations given in this report cover both objectives.Grindability Characteristics When the ores are being studied the information sought is grindability characteristics (grain-size distribution) and the grindability (work required to produce new surface) of a group of ores.When the study is of the machines, several machines are used for a given ore or given types of ores, and the grinding performances of the machines are compared by a grain-size study.Table 1 gives the grindability characteristics and grindability of six substances, one of which is coal. The substances are arranged from left to right in progressing order of tons per horsepower-hour. Curves and graphs are not needed for elucidation. The secret of the ease of interpretation is the order mentioned and the similarity of the sizing analyses. Power records must be complete in grinding studies.The grinding device was a ball, plunger, and mortar called the drop weight.' It may be used to advantage when the amount of material to be tested is too small for the orthodox machines.The upper part of table 1 shows the grindability characteristics by the cumulative-sizing analyses. Note how closely the percentage weights agree for a given sieve size. The lower part shows the grindability in terms defined elsewhere. The present paper should be read in conjunction with that paper."

Jun 1, 1934

By R. A. Friedel

THE UTILIZATION by the Bureau of Mines of infrared and ultraviolet-visible spectrometry in connection with coal research has led to some basic improvements in methods, including a calibration method, a quantitative assessment of infrared spectral energy sources, and the development and perfection of infrared filters and cells. The adoption of a micropipet method to flush organic samples into absorption cells permits the investigation of vapors from organic liquids and the identification of volatile organic compounds. The spectral method has been used to investigate the infrared spectra of metal chelates, the charge-transfer complexing properties of aniline and nitrobenzene, an infrared method for determining the presence of methane in coal-mine air that has been adopted for use in enforcing the regulations of the National Coal Mine Safety Act, and atmospheric pollution including smog and odor-causing oxidation and decomposition of organic materials. Correlation of spectra and structure of organic compounds, particularly aromatics, was studied.

Jan 1, 1966

By Richard F. Hewlett

This report describes how a limited number of preliminary exploration drill-hole assays from a mineral deposit can be used to design grid spacing that is both economic and efficient for subsequent evaluation drilling of that deposit. Relationships between desired precision of the estimate of grade of ore and drilling cost are used to determine the economic drill-hole spacing. The statistical concept of precision in estimating grade of ore is used to determine the efficient drill-hole spacing. Assay data from approximately 50 known copper deposits were studied, and the relationships of the statistical parameters of these deposits were computed. Drilling requirements for various precisions of the estimates of grade of ore were computed for some of these known deposits to serve as guides for drilling future copper deposits. The effect of various geologic factors on the trend in grade of ore and, therefore, on the drilling requirements is shown for certain deposits.

Jan 1, 1965

By M. R. Yenchek

The U.S. Bureau of Mines designed and constructed sensitive and coordination-free ground-fault relays (GFR's) for use on mine power systems. First, a list of GFR attributes for mine ac utilization applications was compiled. These practical guidelines specified design, construction, transient immunity, reliability, and operating criteria. The time-current characteristics of the ac and dc units, subsequently fabricated, were designed to be below the human electrocution threshold. The significant and highly variable capacitance of high-voltage distribution cables was found to preclude the sensing of ground currents in the milliampere range. However, the coordination-free system developed for high-voltage distribution should enhance safety by significantly decreasing response time to ground faults. Implementation of the sensitive GFR technology in the mining industry has the potential to eliminate the majority of injuries and nearly all the deaths resulting from contact with energized components.

Jan 1, 1990

By Lee Blackman

The Malheur-Jordan Resource Areas (MJRA?s) is a tract of approximately 6.5 million acres of federal and non-federal land in the southeast corner of Oregon. This study evaluated the Resource Areas' economically recoverable mineral potential based on geological estimates provided in the USGS report (Smith, 1994). The mineral terranes are believed by geologists to contain undiscovered resources. The geological data is probabilistic; with estimates of the possible number of deposits and their grades and tonnages. Possible future development scenarios range from no development to numerous mines. Based on the analysis performed on these terranes, the most likely (in a statistical sense) future scenario for the resource areas would include the potential for two medium sized, predominately gold, mines. These would supply direct and indirect employment of up to about a thousand workers.

Jan 1, 1995