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By J. Feldman

This report contains a description of the distillation laboratory at Bruceton, Pa., which was established to aid in the separation and identification of the products produced in the synthetic liquid fuel processes under study there. Compounds present in synthetic liquid fuels may include aliphatic from C1 to C60 or greater. Alcohols, ketones, esters, aliphatic carboxylic acids, saturated hydrocarbons, olefins, and diolefins are all found in Fischer-Tropsch products. Coal-hydrogenation products contain, in addition to aliphatic compounds, a large proportion of naphthenic material and aromatic compounds ranging from benzene to coronene; in addition, appreciable quantities of tar bases and tar acids are present. In designing the laboratory, therefore, provision had to be wade for the greatest amount of flexibility and versatility. A great deal of standardization of basic equipment had also to be designed to permit interchange of parts and services.

Jan 1, 1951

By R. H. King

A very simple cold-bend test was devised and tested for evaluating thermoplastic jackets used on mine-power-feeder cables. A test sample is bent into a semi-circle whose radius is equal to the minimum bend radius recommended by IPCEA and then cooled to the, desired test temperature (-35°C). While at temperature, the sample is straightened by pulling the cable ends with a winch arrangement. The results show that of the jackets tested, those which cannot withstand the test literally burst when the sample is straightened.

Jan 1, 1978

By D. R. Tesarik, F. M. Jones, J. B. Seymour, L. A. Martin, T. J. Williams

Determining backfill stress is an important part of evaluating mine safety, whether personnel are working in proximity to backfill or in other areas of the mine where backfill is an integral part of regional support. To assist in determining stress in backfill more accurately, researchers from the Spokane Research Laboratory of the National Institute for Occupational Safety and Health, Placer Dome, Inc. (Turquoise Ridge Mine), Peabody Energy Co. (Foidel Creek Mine), and Hecla Mining Co. (Lucky Friday Mine) used temperature readings recorded by thermistors to correct for the influence of temperature on stress data. These thermistors were positioned in the stems of earth pressure cells installed in backfill. Corrections were then calculated and compared using four different methods: polynomial equations fit to temperature-versus-stress plots before the pressure cells were loaded by overburden, a factor provided by the manufacturer, a theoretically derived factor, and a linear correction factor based on information collected during periods when no mining was taking place. To evaluate the accuracy of these methods, corrected stresses were calculated using each method and results compared to cumulative stresses caused by blasting at one of the mines. Results indicated that only a small percentage of the temperature effect on stress was corrected using the factor from the manufacturer because that factor accounted for only the pressure transducer and not the entire instrument body. Stresses adjusted with a linear correction factor based on information collected during periods when no mining was taking place were the most accurate. Stresses recorded at two other mines were corrected using the theoretical method and the polynomial equations method; the two methods produced similar results. For some time intervals, the results were identical.

Jan 4, 2006

By T. J. Ballard, Austin B. Clayton

"The Union Copper mine is in the Gold Hill district, Rowan and Cabarrus Counties, N. C.The mine was discovered in 1799 and first worked as a gold mine; but copper was encountered at depth, and the property became an important producer of copper. It is estimated that the mine produced 5,000,000 pounds of copper before operations were discontinued in 1907.As part of the strategic minerals program, the Bureau of Mines conducted a development project on the property from July 1943 to November 1943. Eight diamond-drill holes, totaling 2,500 linear feet, were drilled to delineate the ore body. Analyses of 205 core samples were made.Tabulations of sample analyses and drill-hole logs are presented in this report.The project work embodied in this report was under the immediate supervision of Austin B. Clayton, project engineer, and the general supervision of H. B. Ewoldt, district engineer for North Carolina and Tennessee. The preliminary report, written by Austin B. Clayton, was revised and the various figures redrawn for publication by T. J. Ballard under the general supervision of M. H. Kline, chief, Raleigh Branch, Mining Division.Acknowledgment is due the Metallurgical Branch for analytical determinations of the samples.The mine property is 1.5 miles southwest of the village of Gold. Hill, N. C. (fig. 1). Gold Hill is on U. S. Highway 52 between Salisbury and Albemarle and on a branch line of the Southern Railway. The latitude is 350 30' and longitude 80° 21 The tract consists of 553-1/2 acres in Cabarrus and Rowan Counties.A tentative list of the surface-rights ownership is as follows: William Hoy Barringer - 16 acres, A. W. Tucker - 1 acre, Frank Wagoner - 4 acres, and George Barringer - 3-1/2 acres, in Cabarrus County; A. W. Tucker - 2 acres, H. N. Hedrick - 54 acres, and William Atkins - 473 acres, in, Rowan County, N. C.The mineral rights are owned by Alfred Rossiter, Alice R. Hesslein? and the estate of the late Bella Rosenblatt. The attorneys for the owners are Neidle & Taylor, 6 East 45th Street, New York City.The Union Copper mine is in the Cold Hill mining district of North Carolina where gold was first discovered in 1799. The upper parts of the veins in the district were first worked for gold; however, the increase in the sulfide content of the veins with depth rendered the amalgamation process for gold recovery ineffective, and the mines were closed.The period of greatest activity at the Union Copper mine was from 1899 to 1906. At an earlier period the oxidized and leached part of the lode near the surface was mined from a working known as the ""big cut,"" the reported yield of which was $300,000 in gold.3/ The mine has not been operated since 1907.J. T. Pardee3/ lists the probable value of the production of the Union Copper mine as $1,050,000, of which about $675,000 was the value of some 5,000,000 pounds of copper produced."

Oct 1, 1948

By J. M. Kuchta

The Bureau of Mines used laminar hot air jets of l/8- to 3/4-inch diam-eter to determine the hot gas ignition temperatures of various combustible vapor-air mixtures. The combustibles were n-hexane, n-octane, n-decane, a hydrocarbon jet fuel (JP-6), and an adipate ester aircraft engine oil (MIL-L- 7808). Minimum ignition temperatures occurred at a fuel to air weight ratio of about 0.5 and were not greatly sensitive to variations of fuel concentra¬tion. Moderate variations of jet velocity also had little influence on these ignition temperatures. However, these temperatures decreased with increase in heat source dimensions (jet diameter). The hot gas ignition temperatures of the combustibles were not necessarily much greater than corresponding autoignition and wire ignition temperatures when the size (,F the heat source and the ignition criterion were the same.

Jan 1, 1966

The initial results from the magnetic sludge factorial experiment are summarized in Table 2. For ease in interpretation, the four separate variables are identified with the high and low level of each variable being represented by + and - signs, respectively. Several important relationships are evident from an inspection of the data in Table 2. For example, magnetic sludges were obtained only during the high temperature tests. Secondly, with the exception of the last three tests, there is an apparent correlation between settled sludge volume (or sludge settling rate) and pH. Data on residual dissolved Fee+ indicate that precipitation of iron is not complete at pH 8 and room temperature (Tests l, 3, 5, and 7). Although this should not have any confounding effect on the interpretation of the results, it is an important observation and an aspect of the overall conceptual process that should be considered carefully during any future developmental work. The data in Table 2 were employed more fully in the calculation of main effects and variable interactions for each of the three responses. For this purpose, a codified design and calculation matrix, shown in Table 3, was used. The derivation of this matrix is described by Davies.(9) The positive or negative signs for variable interactions are obtained simply by algebraic multiplication of the signs for each single variable involved in the interaction. Main effects and interactions are calculated by multiplying the response values (Table 2) by the corresponding effect elements (Table 3), summing the results, and dividing by 8. The resulting value for single variables is also sometimes designated as an average effect, since (for tyro levels of the variable only) it is simply the difference between the average response of all trials carried out at the first level of the variable (factor) and that of all trials at the second level. If the effect of one variable changes at different levels of another variable, the two variables are said to interact. The relative importance of the variable or variables in question is reflected by the absolute magnitude of the calculated main effect or interaction. First-order (two variable) interactions are usually easy to interpret in terms of the physical behavior of the system. Second- and higher-order interactions are often less readily understood, and are often of minor significance in any case. The main effects and interactions derived from the present study in the manner described above are listed in Table 4. It should be noted that

Jan 1, 1971

By John H. Soulé

"INTRODUCTION Spodumene and lepidolite were shipped from the Harding pegmatite deposit, Taos County, N. Mex., in the period from 1930 to 1930. Tantalum minerals were noted as early as 1924 and described in 1931 3/ but no tantalum ore was shipped until 1942. The deposit was mapped and studied by geologists of the Federal Geological Survey and engineers of the Bureau of Mines late in 1942 and early in 1943, and a Bureau of Minus exploratory project was carried out in 1943. 4/ Thu following report presents the results of that project.ACKNOWLEDGMENTSIn its program of exploration of mineral deposits, the Bureau of Minos has as its primary objective the more effective utilization of our mineral resources to the end that they make the greates possible contribution to national security and economy. It i the policy of the Bureau to publish the facts developed by each exploratory project as soon as practicable after its conclusion. The Mining Branch, Lovell B. Moor, chief, conducts preliminary examinations, performs the actual exploratory work, and prepares the final report. The Metallugiical Branch, R. G. Knickerbocker, chief, analyzes samples and performs beneficiation tests. Both these branches are under the supervision of Dr. R. S. Dean, Assistant Director."

Dec 1, 1946

By J. J. Drost

This Bureau of Mines investigation studied the effect of thermal treatments upon concentratability of a western Mesabi Range nonmagnetic taconite ore and is a sequel to Bureau of Mines RI 7567. Magnetic tube tests were used to develop the data needed to calculate separation efficiency, the primary measure of concentratability. A horizontal tube furnace was employed to heat treat and reduce the hematitic ore samples. The two variables studied were roasting temperature and cooling method. The manner of cooling, either by slow cooling or quenching in water, produced no significant difference in concentratability. Roasting temperatures employed ranged from 500° to 1,000° C, and a temperature of 650° C effected the best concentratability. The temperature of 650° C correlated with the most effective roasting temperature for grindability.

Jan 1, 1973

By R. O. Pynnonen

This publication is an analysis of reports to the Bureau of Mines of 44 fatal accidents that occurred during the operation of rubber-tired, front-end loaders in the mineral industry. The causes of the accidents, the nature of the work being performed, and recommendations for preventing similar accidents are included.

Jan 1, 1967

By Arnold B. Hubbard

This report describes a method of concentrating the insoluble organic material (kerogen) in a rich Colorado oil shale without any apparent alteration of its original chemical form. The method involved treating finely pulverized shale with dilute acetic acid at room temperature to remove the carbonates, which act as a cementing agent for the shale, and cause the shale particles to partly disintegrate into the organic and inorganic components. The acid-treated shale then was centrifuged in different liquid mediums ranging from 1.4 to 1.15 gravity to effect a mechanical separation. From a Colorado oil shale containing 48.0 percent ash, kerogen concentrates containing 43.3 to 8.7 percent ash were obtained. The carbon:hydrogen ratios of the kerogen in the original shale and the different concentrates were essentially the same. The oil:kerogen ratios calculated from Fischer assays of the above samples were essentially the same, regardless of the organic or inorganic contents. This was also true of the assay water:kerogen ratios of the same samples. These data indicate that no significant change occurred in the kerogen during the concentration process.

Jan 1, 1952

By Richard D. Miller

The helium resources base of the United States was estimated by the Bureau of Mines to be 961 Bcf as of January 1, 1983. These resources are divided into four categories in decreasing degree of assurance of their existence: (1) helium in storage and in proved natural gas re- serves, 271 Bcf, (2) helium in probable natural gas resources, estimated at 202 Bcf, (3) helium in possible natural gas resources, estimated to be 351 Bcf, and (4) helium in speculative natural gas resources, which makes up the remaining 137 Bcf. These helium resources are further divided into depleting, nondepleting, and stored classifications. The depleting resources are those associated with natural gas fields that are, or will be, produced for the natural gas they contain. All of the helium in potential (probable, possible, and speculative) natural gas resources is included in this classification. These depleting resources are estimated to contain 789 Bcf of the total helium resource base. Helium resources contained in nondepleting natural gas resources, those in shut-in, abandoned, or otherwise nonproducing natural gas fields, are estimated to total 134 Bcf. There is 38 Bcf of helium in storage in the Federal Government- owned Cliffside Gas Field near Amarillo, TX.

Jan 1, 1985

By Charles A. Kumke

In June 1942 , ' the Bureau of Mines selected the Zonia copper mine , near Kirkland , Yavapai County , Arizona , as a property meriting investigation in connection with its search for supplies of strategic minerals for use in the war . The following month , representatives of the War Production . Board conferred with Bureau officials and requested that the property be explored with the object of determining the tonnage and grade of ore that could be brought into production quickly and mined cheaply by open-pit methods . The work wa's designed to verify information submitted by the owners in support of an application for a Government loan. It was essential that the investigations be completed promptly , so that operations might be planned and copper produced for war needs . The investigations called for surface trenching , diamond drilling , and check sampling of underground workings . Unable to purchase equipment for trenching without considerable delay , the Bureau saved time by borrowing most of the necessary items from the Golden Queen mine of the Gold Fields Development Co. at Mohave , Calif. This company , whose engineers had sampled some of the old trenches , had a tentative agreement with the owners to operate and manage the Zonia mine in event the loan was granted . Additional equipment was borrowed from two Governmental agencies . The exploratory work , completed in 16 weeks , was carried on 7 days a week .

Mar 1, 1947

By Len Blackman

The Absaroka-Beartooth Study Area is a tract of approximately 1.4 million acres of National forest land in southern Montana, part of the Greater Yellowstone Area. This study evaluated the mineral potential of four mineral terranes containing undiscovered resources in the area. 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 many mines, including some very large. As two thirds of the study area is within the Absaroka-Beartooth Wilderness, the future development scenarios reflect the area's mineral potential, not what we expect to see in the foreseeable future. Based on the analysis performed on these four terranes, the most likely future scenario for the study area would include the potential for two medium sized, (predominately) gold, mines, each employing a few hundred workers. There is a small chance, less than 5%, that a large Porphyry Copper or Superior Iron deposit would be discovered and be economically feasible to develop.

Jan 1, 1994

By N. Kyriazi, W. Duerr, J. Shubilla, J. G. Kovac, J. Kravitz

A joint effort by the Bureau of Mines and the Mine Safety and Health Administration (MSHA), U.S. Department of Labor, was undertaken to determine how well self-contained self-rescuers, deployed in accordance with Federal Regulations (30 CFK 75.1714), held up in the underground environment. This report presents findings regarding laboratory-tested breathing apparatus from the first year of a 5-yr program as well as other related findings. The SCSR's were tested on human subjects and on a breathing and metabolic simulator. These results indicate that the apparatus, if well-treated, perform as expected except for manufacturing defects or quality control problems, which are identified. However, when the apparatus are carried in and out of the mine every day and stored at the working section, they may suffer abuse that can be extreme. Physical signs of abuse, unless extremely obvious, frequently are not detected by the miners or the mine operators; this poses a danger to a potential user in case of emergency. Recommendations include improved training in inspection procedures.

Jan 1, 1986

By D. H. Baker

THIS REPORT presents the technique and equipment used in determining the hardness of titanium sponge. Detailed descriptions are given of the methods used in preparing test samples for chemical analysis and hardness testing, the method of melting and surfacing test ingots, and the technique of reading Brinell-hardness impressions. The arc-melting furnace described, for which engineering drawings are included, will produce from 70 to 90 double-melted buttons each 8 hours of operation. Experimental data are also presented depicting the effect on hardness of the methods of surfacing specimens, temperature of test specimens, and the effect of time at test load. These data show that surfacing of the specimen involves no critical machining operations but that the test surface must be paralleled by a relatively flat surface for contact with the anvil of the Brinell tester. The heating of a specimen to 150° C. during surfacing does not materially affect the results if the ingot is cooled to room temperature before the hardness impressions are made. The optimum time at load appears to be approximately 30 seconds, but load times of as much as 1/ ½ minutes will not cause major errors.

Jan 1, 1959

By J. B. Littlefield

The Greenburg-Smith impinger was developed at the Bureau of Mines in cooperation with the United States Public Health Service in 1922 in the course of an investigation of dust-sampling instruments available at that time. Although it is not used extensively outside of the United States, it is now soused in this country to collect samples for the determination of any dustiness, and most of the information correlating degree of dustiness with physiological effect has been obtained by the impinger method. The chief disadvantages in the use of the regular impinger, especially in mines and other places accessible with difficulty, are its bulk weight, and power requirements. It requires a source either of electricity or of compressed air, which necessitates connections and extension of existing supply lines to each sampling point; the only alternative is the use of a relatively large pump hand-operated with considerable effort.

Jan 1, 1937

By R. S. DeCesare

Operation of the Bureau of Mines raw refuse continuous separation pilot plant is described, including modifications made to plant equipment for improved performance. Products recovered from refuse, many of which have been evaluated by other laboratories and private firms, are discussed. Sampling procedures used in the pilot plant and detailed data obtained from processing refuse from 13 municipalities are presented in appendixes. Fuel evaluations made on combustible fractions of refuse from the various municipalities are also presented. Information and data obtained at the pilot plant have been used to assist many municipalities in solving their urban refuse problems.

Jan 1, 1980

By L. C. IlsLey

A n'Ulllber or operators have installed f'lBJ!le-proot or so-called exploaion­ proot electrical outfits, under the impression that such equipments met· all of the reqiirements of the Bureau of Mines as regards safety, There a.re todq in gaseous mines a large nwnber of euipments that have not been approved by the Bureau ot Mines, and unless mod1f'iecl could not receive sucl1 approval.. These e qu.ipments represent in pa.rt the product of manufacturers whil ha.ve never submitted. equipments for insri?ction or tests. and iri pat types developed. previous to the safety work or the bureau. Sometiu.es saleimen advocate the use of unapproved. types in gaseous mines in place of Bureau of Mines approved outfits, the purchase price beini slightly less than approved types,

Sep 1, 1922

By Scott Turner

Since my whole life has been spent in the mining business , I naturally tend to address my remarks particularly to the newly- graduated mining and metallurgical engineers among you . To a certain extent , all forms of engineering principles are involved in the training of the mining engineer , and most sorts of engineering are certainly utilized by him , so that every one of this graduating class is concerned with the field I propose to discuss . The fact that , beginning with to - day , you will always be styled engineers , indicates that you have passed successfully through preparatory school , and have survived the hard grind of the technical college . One object of your training here has been to instruct you in accurate , close , and clear thinking . Your minds have been taught to act directly , calmly . and always to the point . By now , you should know how to get facts , look far , and think through . You are supposed to be willing to recognize and adopt sound engineering principles and practices , in so far as they are known to you , and to furnish character , ability , and devotion to your calling . Some of you may have had a general college course before coming here to specialize in engineering . Where that has been possible , I hope it is the case , since a liberal educational course tends to make the alumnus more flexible and adaptable than the purely scientific graduate. The broader education enables one to change , with less serious loss , from one job to another; ready adaptability is a great asset ; the engineer should be capable of much more than a single special task . The necessary preliminary training for a professional occupation is intellectual in character , involving knowledge , and to some extent learning , as distinguished from mere skill . The well -balanced engineer is expected to embody a happy combination of theory and fact , of pure science and material reality ; experience shows that he is apt to give a good account of himself , once he gets the chance . For the long pull , the importance of unquestioned integrity can not be overemphasized . Leaders of big business sometimes have need for a man as agile and unscrupulous as a cat on a back fence ; on occasion , they may have to employ brilliant , smart , spectacular , and crafty people , but when the special purposes for which such men are hired have been accomplished , they are no longer wanted . Given natural health , intelligence , ability , and adequate training , probably the characteristics most admired in the young employee are steadiness , dependability , and loyalty . The last is the best . If you can not be simple , direct , and faithful in your dealings with your administrative superiors , no one will want you for long . I believe these points are of primary importance to the young engineer . Your groundwork must be right before you can get far . These personal characteristics are what eventually determine your relations with men and affairs . They are vital in the human engineering which may be a large part of your work .

Aug 1, 1932

By L. H. Kalenowski

The metal lithium, its alloys, and its salts are becoming Increasingly important as industrial materials. Lithium metal, because of its great affinity for elements, such as nitrogen, hydrogen, oxygen, sulfur, phosphorus, carbon, and silicon, has become important for a wide variety of uses, ranging from purifying helium gas by removing the nitrogen to scavenging molten metals of undesirable impurities. The excellent fluxing properties of lithium salts have found increasing use in such applications as fluxes for welding aluminum and in lower melting ceramic glazes and coatings. Lithium chloride is one of the most hygroscopic salts known and is widely used as a dehumidifying agent. .About 17 lithium minerals are known. Four of these have commercial importance: Amblygonite, lepidolite, zinnwaldite, and spodumene. Spodumene is the most important source of lithium and lithium salts at present, but sizable deposits of amblygonite occur in the pegmatite area of the Black Hills of South Dakota. The size and nature of these deposits preclude the, possibility of, any assurance of an adequate supply of amblygonite for an operation processing only this mineral. Frequently spodumene and amblygonite occur associated in pegmatite minerals. Preliminary investigations indicate that a simultaneous recovery of spodumene and amblygonite can be made by froth flotation. A single process for treating spodumene and amblygonite or mixtures of thorn, would make possible more use of amblygonite as a source of lithium and obviate the separation of spodumene and amblygonite when they occur together.

Jan 1, 1952