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By W. D. Mcmillan

Kaolin, or china clay, is the term applied to a group of hydrous aluminum silicates. Because of its purity, light color, and refractory properties, kaolin is used extensively in the manufacture of high-grade ceramic wares and as a filler by the rubber and paper industries. Although there are numerous pottery and enamelware plants in Texas, and large rubber and paper industries; all of the kaolin used in these plants is from other States, There are two known occurrences of kaolin in Texas, namely, the Leakey deposit in Real County and the several deposits of the Medley district in southern Jeff Davis County. An investigation of the Mueller kaolin deposit in the Medley district was undertaken by the Bureau of Mines. Following an examination of this deposit by W. D. McMillan, engineer in charge of the Texas field office of the Bureau of Mines, a proposal was made to investigate the deposit by diamond core drilling.

Jan 1, 1949

By S. M. Runke

"During the past three years the Bureau of Mines has carried on an extensive research program at the Rolla Laboratory for the beneficiation of low-grade Arkansas baixites by ore dressing methods. As a result of this study a 50-ton pilot mill was designed and constructed at Bauxite, Arkansas, by the Bureau to continue the investigation on a semi-commercial scale. The built both to reduce the experimental work to practice and to obtain operating data that cannot be determined by laboratory or small scaleTen samples of bauxitic material were mined and stockpiled at the plant site to ensure an ample supply of material for milling in the pilot plant. These samples were obtained from various bauxite deposits in Saline and Pulaski Counties, Arkansas. The deposits were selected as typical of a wide range of bauxitic material which would necessitate treatment under different conditions and by various concentration methods. All of the samples contained a higher silica content than permissible in Bayer-grade bauxite and several contained so much iron oxide that the available alumina content of the ore was mate¬rially lowered. From data obtained by milling operations on these ten samples, milling characterietics of most of the ores in the district should be predictable. This paper summarizes the results obtained in the laboratory testing of representative samples of each stock pile, and the results of small scale continuous testing of the composite sample of the ten stock piles in the gravity-flotation pilot plant at the Rolla Laboratory."

Aug 1, 1946

By O. T. Barrett, R. F. Aberethy, H. N. Cooper, Thomas Fraer, William L. Crentz

"INTRODUCTION The object of the techniques described in this report is to determine the possibilities of separating the components of a raw coal into such grades as may be necessary to recover some exceptionally clean functions for special purposes.To do this commercial gravity methods would require separation at very low specific gravities, entirely outside the range of conventional practice. Hence, a technique has been developed for breaking down cool ample, into very close fractions within the gravity range of the (-lean coal matter as well as for separating it from the refuse and particles.Such data on the fundamental specific-gravity consist of the clean-coal matter will serve to appraise the difficulty of the problem and to chow be accomplished if and when effective methods of making such separations commercially are developed."

May 1, 1945

By Robert E. Hershey

1. Estimates of reserves were made for three coal beds in Hamilton County the - Lantana, Sewanee, and Richland. Nine coal beds have been mined at one time or another in the county, but not enough information was available to estimate reserves in any beds other than the three given. 2. Known measured and indicated reserves for all beds, based on a minimum thickness of 14 inches and on 1,800 short tons per acre-foot of coal in place, are estimated to be 53 million tons as of January 1, 1954. Of this total 35 million tons is in beds 28 inches and more thick. Areas in each bed were omitted from the estimate because available data relative to the bed characteristics were insufficient for making an estimate conforming with the definitions of measured and indicated coal adopted for this study. Should future drilling or development prove re-serves in these areas, such reserves should be added to the total estimated reserves determined by this investigation.

Jan 1, 1956

By J. M. Provost

1. Estimates have been made for eight coal beds in Marion County, but only the Pittsburgh is important from a production standpoint at this time. The Pittsburgh bed has the largest recoverable reserve, and the Sewickley is second in importance. 2. Known measured and indicated reserves thickness of 14 inches and on 1,800 short tons estimated at 3,141 million tons, as of January lion tons is in beds 28 inches and more thick in all beds, based on a minimum per acre-foot of coal in place, are 1, 1955. Of this total, 2,983 mil-Areas in each bed were omitted from the estimate because available data relative to the bed characteristics were too meager for making an estimate that conforms with the definitions of measured and indicated coal adopted for this study. Should future drilling or development prove reserves in these areas, such reserves should be added to the total estimated reserves.

Jan 1, 1956

By H. L. Gilbert

Improvements in production of high-purity chromium metal by magnesium reduction of anhydrous chlorides and by hydrogen treatment of electrolytic chromium are reported. Hydrogen-treated chromium has been arc-melted, and the arc-melted material has been successfully forged, rolled, and swaged. The material also has been forged at liquid-air temperatures. X-ray and metallographic studies indicate the recrystallization temperature of rolled chromium sheet to be about 750° C. Preliminary investigation of hot-bending characteristics of rolled chromium sheet shows the minimum bending temperature to be about 325° C. The heat resistance of chromium has been investigated.

Jan 1, 1952

By Amanda S. Azman

It is known that exposure to high sound pressure levels can lead to permanent hearing loss; however, many workers, in mining as well as other occupational sectors, frequently receive hazardous noise exposures. The National Institute for Occupational Safety and Health (NIOSH) recommends using a criterion level of 85 dB(A) for implementation of hearing loss prevention programs1. But, despite engineering and administrative controls, workers continue to exceed their recommended daily noise dose. Hearing protection devices are worn as a final defense against noise overexposure, but many workers have difficulty communicating or detecting warning signals while wearing them. New electronic technology has been integrated into conventional hearing protectors to allow for some degree of sound restoration. Research is currently being carried out within NIOSH, Pittsburgh Research Laboratory (PRL) to evaluate the performance of sound restoration hearing protectors. Due to certain features of the devices, such as their non-linear performance and possible manipulation of electronic settings, there are obstacles to testing them using the existing standard hearing protector test methodology (ANSI S12.42-1995 and ISO 4869-3:1997). These and other issues related to testing these devices are outlined within this paper, and possible solutions are discussed. Measures of attenuation properties have been done on a set of the devices and preliminary findings indicate that new test methods, or at least modifications of existing methods, must be developed to accurately determine device performance. Furthermore, it is necessary to know not only the attenuation properties of such devices, but also the degree to which speech intelligibility or recognition of warning signals is preserved, as compared with conventional hearing protectors. As additional data is collected a more accurate and reliable test methodology will be developed, and a more comprehensive picture regarding device performance will be determined and disseminated.

Jan 1, 2008

By H. C. Fuller

This paper discusses 105 production runs at Boulder City, Nev., in which titanium metal was made in 200-pound batches. It describes the equipment and techniques used in preparing raw material, the reduction process, and the removal of the reaction mass from the reaction vessel. Also, some data on man-hour requirements are presented. The main emphasis was on producing ductile-grade titanium and developing a standard procedure for obtaining a consistently pure product. Some departures from techniques used before were found to be desirable. The most important of these was the use of a sealed room with a controlled dry atmosphere in which the reaction vessel was opened and the reaction mass removed. This minimized the moisture taken up by the magnesium chloride in the reaction mass, and it could be purified successfully by vacuum distillation. Using the dry room also made it possible to leave al-inch shell of the reaction material on the walls of the vessel, which lowered the iron contamination and eliminated the labor and time-consuming job of cleaning the vessel after each reduction. Another change was lowering of the temperature during reduction to 750° C. instead of 850° C. This was found to give good results more consistently. The first poke to break the crust during reduction was eliminated, as it was found to be unnecessary and only added more work and was another possible way of introducing air. A rotating feed arm was installed in the reaction vessel to distribute the titanium tetrachloride over a larger area and, thus, prevent local overheating. The process, conducted in a batchwise manner as described and followed by good purification and fusion, produces a metal adequate in quality for nearly all purposes.

Jan 1, 1952

By C. Özgen Karacan

Longwall mining is an underground mining method during which a mechanical shearer progressively mines a large block of coal, called a panel, in an extensive area. During this operation the roof of the coal seam is supported only temporarily with hydraulic supports that protect the workers and the equipment on the coal face. As the coal is extracted, the supports automatically advance and the roof strata cave behind the supports. Caving results in fracturing and relaxation of the overlying strata, which is called "gob." Due its highly fractured nature, gob contains many flow paths for gas migration. Thus, if the overlying strata contain gassy sandstones or sandstone channels, gas shales or thinner coal seams which are not suitable for mining, then the mining-induced changes can cause unexpected or uncontrolled gas migration into the underground workplace. Vertical gob gas ventholes (GGV) are drilled into each longwall panel to capture the methane within the overlying fractured strata before it enters the work environment. Thus, it is important, first to understand the properties of the gas reservoir created by mining disturbances and, second, to optimize the well parameters and placement accordingly. In this paper, the production rate-pressure behaviors of six GGVs drilled over three adjacent panels were analyzed by using conventional multi-rate drawdown analysis techniques. The analyses were performed for infinite acting and pseudo-steady state flow models, which may be applicable during panel mining (DM) and after mining (AM) production periods of GGVs. These phases were analyzed separately since the reservoir properties, due to dynamic subsidence, boundary conditions and gas capacity of the gob reservoir may change between these two stages. The results suggest that conventional well test analysis techniques can be applicable to highly complex gob reservoirs and GGVs to determine parameters such as skin, permeability, radius of investigation, flow efficiency and damage ratio. The insights obtained from well test analyses can be used for a better understanding of the gob and for designing more effective gob gas venthole systems.

Jan 1, 2009

By Joseph Gersic

The U.S. Bureau of Mines assessed mineral resources of the BLM Malheur-Jordan Resource Areas (MJRAs) in southeastern Oregon in 1993 and 1994. The study relied heavily on acquiring and analyzing existing data. In order to efficiently handle and analyze a large quantity of data, a minerals information management program, informally called MINFO, was developed as a frontend for three databases created to store basic information gathered during the minerals resource assessment. The MINFO program will also provide the BLM with a method of tracking and updating minerals information in the future because program modules in MINFO allow the addition of new data and the correction of errors, creation of print files, transfer of data to other database formats, exportation of data to other software packages, and creation of AutoCAD script files to be used in conjunction with AutoCAD to produce maps. The report specifically identifies significant past and present mineral exploration and development activities and possible areas of future mineral exploration and development. These areas are informally designated as areas of development interest or ADIs. The report contains a scenario of what mineral development might reasonably occur in the foreseeable future if the BLM does not substantially change its present resource management plan, and it shows the possible socioeconomic impacts of that development. The uncertainty of the political and economic situation makes it extremely challenging for the USBM to accurately predict a reasonably foreseeable development scenario. The reasonably foreseeable development (RFD) scenario developed by the USBM for the BLM indicates short-term RFD of minerals should have a negligible socioeconomic impact, and longer-term RFD of minerals should have a slight socioeconomic impact on the MJRAs. The mining industry is facing a rapidly changing business and regulatory environment in Oregon. Several signal changes have occurred recently, including State regulations that require significant bonding prior to the startup of "chemical process" mining, an initiative by a special interest group to stop all chemical process gold mining within the State, and an opinion by the Oregon Attorney General (AG) banning all forms of placer mining without exemption. In the AG opinion, not even gold panning is allowed, and the prohibition applies to mining claims on Federal lands. The State legislature may amend the statute to allow small scale placer mining to occur, as was allowed under an AG opinion issued in 1982. These and other changes occurring at the local, State, and National levels are making it more challenging for the mining industry to operate in the United States. Several epithermal gold properties in the MJRAs attracted the mining industry's interest. Only the Grassy Mountain Project of Newmont Grassy Mountain Corporation may be developed in the next few years. It is probable that at least two other properties will be developed if Grassy Mountain is successful. Mining companies are waiting to see the effect recently promulgated State mining regulations and more stringent proposed regulations, particularly bonding regulations, may have on Grassy Mountain. Resources of bentonite, diatomite, and zeolite are abundant. The almost Ubiquitous stone, sand and gravel, and semiprecious gemstone resources also were examined. Little environmental or socioeconomic impact is expected from reasonably foreseeable development of these mineral resources.

Jan 1, 1994

This report is the 23d in a series summarizing research and technologic work by the Federal Bureau of Mines on coal and related investigations; it is the fifth report to be issued on a calendar-year basis.2/ Publications by Bureau personnel in 1958 are cited;3/ in addition work in progress during the year is briefly described. To conserve our reserves of coal the Bureau of Mines conducts a program concerned with the development of fundamental information on coal characteristics and behavior, and the improvement of technology related to its production and utilization. The ability to anticipate and meet future demands for coal depends on a number of factors: (1) Knowledge of reserves from a stand- point of both quantity and quality; (2) the development of improved mining methods, health and safety measures, and preparation techniques that will insure its most efficient exploitation; and (3) knowledge of the controlling factors in efficient use of coal in combustion, carbonization, gasification, direct and indirect hydrogenation, and other new processes. The Bureau is concerned with each of these areas.4/,5/

Jan 1, 1960

Nineteen eighty-seven was a year of significant change in the Bureau of Mines-change to help it better adapt and respond to the wide range of new challenges facing the U.S. mineral industry. The Bureau has been regarded as the world's premier mineral information and research agency. Its authoritative, comprehensive data and its pioneering research have contributed significantly to the minerals position of the United States. Yet no organization in today's complex, dynamic world, with its rapidly advancing technologies, can afford to rest on its laurels. Mission and program must be constantly fresh and relevant to the day's issues and problems. Moreover, rather than reacting to events, the organization must strive to anticipate and prepare for them. It must have a sense-a vision, if you will-for the future.

Jan 1, 1987

By F. S. Crawford

The wide variation in the medical facilities, type of accident reports and provision for the welfare of employees, in addition to the compensation provided by the various State laws,- was -studi-eci, by the.. wri-ter in the Lake .. Superior_ r.egion . .. - -Several cDmpanies f~rnished. the information which follows. Names have been omitted , ~ut the information should be of .intere·st to companies desirous of improving t_his branch of thej..r accident-prevention work. : . . --Because a summary of the metho.ds used would merel:y: result in _ a.n a.ttempt to set _up an ideal, it was concluded that in preparing this paper a statem.ent .of_ tbe individual methods of -each company wou-l d .b-e .Qf .. the most inte-res.t, . and the.y h~ve . been .. li.steq with .no regard to the size of the company . . ··· -In the - appendix are -a -number of report. forms used by .various _operators for reporting accidents to t he company and .to the State. These are self- explanatory. and many a re mentioned in -the body of circu-1-ar-.

Mar 1, 1932

By Walter W. Kaufman

The braking performance of underground, rubber-tired, coal mining vehicles is evaluated. Surveys of mining equipment and braking manufacturers and underground stopping tests are discussed as they relate to this evaluation. Stopping performance recommendations are proposed.

Jan 1, 1977

By Michael L. Clar

The U.S. Bureau of Mines contracted a study to determine the feasibility of water diversion and overburden dewatering for underground coal mines in the Appalachian Region. All relevant published literature pertaining to the occurrence and control of surface and groundwater in underground coal mines was reviewed and organized into a bibliography. The impacts of mine water with respect to health and safety, production, environment, and costs were assessed. Sources of water inflow into underground mines were described. A summary description and evaluation of techniques that can be used to reduce the amount of water entering underground coal mines was prepared. A review of engineering practices currently used by operating coal mines in the Appalachian region to prevent the movement of ground and surface water into active coal workings was conducted. Major emphasis was placed on the identification of the geologic and hydrologic con¬dition of the site, onsite inspection of the methods used and an evaluation of their technical and cost effectiveness.

Jan 1, 1981

[lllc purpabr at thla report Vd, Lu JeLermlnr the health ar1J sdfet?; Nene11Le a octatc?J ultll Lne oar L.t support Ydlll ..up.I,ated lu dltetllative cupPurt svsLem, larrellLty hcle.g uaeJ af the Len,::rat 1, UI.Jlng 11-al tl. .1 a d 1 c L V h S LIdl'. L dal. I -ten- lu L he tt I .. L'., etuJ I e. 11'? L_1,1'1,11 .Jtd.. it, ..urn,at'l core ,LuJICCill JhLdll, an.: ...,La -IL .utia_tel .an LI?r oar of -l: l,.!rl .a..a. Ma terI.I auJ ...11,mc[Ii -ldla,tutcle 11. LI.ac .uwIttIca Welt a, a.. V.alte,, L.. .:Ltail, ..,,L., uI. LuClu,alug) Lelll anci ur devel?puJ I.,r Cul r1 , all. ...~.,rLrI Vt,ILt 1.'ere ~e,1C L? .Lher Gentiaii m111cc t, UL.-rye a Variety o. a rL vyl I pp.1Ca:t..n:. 'a.la IrL ..,_wLeiti, Iapl,.III ,tall ~,..:. IL all, maLertdl c1,arait-erlstIcs, JIRICn,IUIIe. and laden ul1.1 ILc rrgatrelaeuls. ,1 r.? p.'rt .a pro-1Jd, labor rep altrlarnts Jdta and illtlitI ieS tie l,ealtll d?J ,atetV ISSUC ,u-1aled Wit su furl Wall a an, CJl,wttuctSOn, I'aLentiaI appll.at1ou:. Ior support Walt, ,a,. , a, sdV.u,L111 .., u.1 retreating lungval1, single -t r-, roar al,- pi r. [,-+ln, anJ SuhIU..,Ina, Sill] b1OpplllgL ale 1:111neated aid al? e.aIWRac AS Sddemcni LV pre,C'IIL..: .,f LI. Clabllhty r+t rlul,I.,y111I? ulg4,rt .I Le.l,lwlug,. Lr i,,,rCASC Lllc rtCVLLrS rat, u., retrc.+tlnp .unui.,11? ur L., elply, A d v Ctnp IuI-,wall in uer;-!y iy1ng seam, . 11111.a1L .a1,.'iI1.-I,.. nr S.IU1tIVlil a1 milItlI; Lust, La LIldnt;2S L.~ gey support Vait Id tdmcLera la dlaa presents,.]

Jan 1, 1980

By John E. Conley

The need for lightweight aggregate for use in concrete products ,and structures has caused the Bureau of Mines to undertake an investigation to determine the availability of suitable raw materials and to study methods, procedures, and equipment to supply that need. Evidence is at hand to prove that the shortage of lightweight aggregate is nationwide. A survey recently covered in a report (13)5/ by the Construction Branch of the National Housing Agency has pointed out the locations in which lightweight aggregates are produced. A study of this information discloses that the producing centers are widespread, and that certain areas, notably the region east of the Mississippi River, and especially the sections along the Atlantic coast line and the Southeastern States, have only a few such plants. Certainly, many localities are badly in need of installations equipped to provide an ample supply of high-grade lightweight aggregate. The work undertaken by the Bureau of Mines includes investigation of the use of clays, shales, slate wastes, coal-mine wastes, diatomite-clay combinations, and various other 'mineral mixtures as possible raw materials. Likewise, special consideration has been given to the development' of equipment and techniques to produce the lightweight products.

Jan 1, 1949

By P. M. Ambrose, A. C. FtELDNER

This , the twelfth annual report of research and technologic work conducted by the Bureau of Mines on coal and coal products , summarizes the research and tests conducted frah July 1, 1946, to July 1, 1947. The organic act of Congress establishing the Bureau of Mines authorized tech- nologic investigations of all phases of mining, preparation, treatment, and utilization. These investigations cover eight main fields of activ-. projects varies from time to time. The on ity. The emphase-half of the coal reservos of the world. United States These reserves are not always of the quality desired or in the place where they could best be used. It is necessary to continue research in order that increased output, greater recovery, and better quality can be main- tained under safe mining conditions. Coal comprises 98 percent of the known fuel reserves of the United States and ad eventually must take over much of the requirements now supplied by petroleum and natural gas.. The purpose of this report is to bring to the reader a resume of the work of the fiscal year. The material presented herein is based largely upon publications. In a few instances the results of research that would not otherwise be available in the immediate future are presented. For details concerning the research, it is suggested that the readers consult the publications given in the footnote references." Collected references to all Bureau of Mines publications on coal are published in a series of bibliographies. Technical Paper 576 covers 1910 to 1935; Technical Paper 639 covers 1935 to 1940; and Technical Paper 698, issued in 1947; covers' 1940 to 1945.

Jan 1, 1948

By R. Van A. Mills

Rapid deterioration and destruction of metal equipment in oil and gas fields cause waste of resources and financial losses that must be lessened or eliminated if operations in many important fields are to continue profitable. The magnitude of this destruction is proved by the huge consumption of iron and steel pipe, tubing, casing, pump valves, and sucker rods to replace worn-out equipment, and by the amount of such equipment that is left in wells or junked. (See PI. I, A and B, and PI. II, A and B, and Fig. 14, p. 61.) This destruction of equipment constitu~es in itself a serious waste, but contingent production troubles, such as underground leakage of oil through defective tubing and pumps, and the consequent loss of oil and gas because of damage to pay sands by infiltrating water and silt, frequent and costly repairs with necessary suspension of production, and the ultimate injury to or loss of valuable wells, often cancel all operating profits. Many of these troubles result from rapid destruction of metal equipment by corrosive waters. The strata penetrated by the wells usually contain saline waters. Certain types of these waters, with their associated gases, are intensely corrosive; they attack well casing or tubing so vigorously as to riddle it with holes, rendering it useless in a few years or even a few months or weeks after it is installed. Pump plungers, working barrels, balls and seats of valves, and screen pipe, as well as lead lines and other surface equipment, are ruined with equal rapidity. The development and application of practical methods to retard or prevent this corrosion are among the most urgent problems of the oil and gas industry. Although much progress has been made in preventing the corrosion of metals, the need for reducing the damage from corrosion in oil and gas fields is still imperative. This is especially true of underground corrosion in the wells, because underground conditions favor corrosion and are difficult to study; hence they have not been thoroughly understood. In efforts to stop ~amage to oil and gas field equipment by corrosion, numerous methods have been proposed or tried with varying success. Some of these methods are cheap and effective. However, it is surprising that in many important fields the damage by corrosion is accepted as necessary or unavoidable, although cheap and effective methods that have been developed and successfully tried elsewhere might greatly reduce the trouble or eliminate it. This bulletin describes common causes and effects of oil and gas field corrosion and outlines methods of abating the damage. In order to accomplish this purpose best, the writer has avoided taking sides in controversies between the advocates of different metals for oil-field use; instead he describes the methods of combating corrosion in the various fields and suggests experiments that may yield valuable results. Throughout the paper he has freely used information from published reports of other investigators.

Jan 1, 1925

By A. E. Kehew

Earth resistivity surveys using the Wenner electrode configuration were made in unmined areas and reclaimed spoils at three surface lignite mines in western North Dakota. The study sites were the Center, Indian Head, and Falkirk Mines. Automatic interpretation of the curves was accomplished with the method of Zohdy and Bisdorf (1975). Overburden materials become more homogeneous with respect to resistivity during the mining and reclamation process. The spoils curves show localized hetero-geneities probably related to discontinuous moisture content variations in the spoils. Consistent resistivity differences in spoils occur between mines with over-burdens of different mineralogic compositions. Groundwater chemical composition in terms of total-dissolved-solids (TDS) is inversely correlated (r=-0.61) with apparent resistivity at the 80-foot spacing from a survey centered at a piezometer screened near the base of the spoils. Better inverse correlation is probably pre-vented by high variability in TDS within the spoils groundwater. A useful predictive relationship may be the plot of mean apparent resistivity at the 80-foot spacing for ar. entire mine against mean TDS for all wells in spoils at that mine. Data from more mines are needed to test the hypothesis.

Jan 1, 1982