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By Selim E. Woodworth

This paper, describing the milling practice on the Mother Lode as typified in the mill of the Argonaut Mining Co. at Jackson, Amador County, Calif., is one of a series prepared by the United States Bureau of Mines. The data herein presented and furnished through the courtesy of E. A. Stent, managing director and vice president of the Argonaut Co., covers operations from 1914 through the year 1929.

Jan 1, 1931

By W. D. Mcmillan

During the fall of 1943 the Bureau of Mines put down four churn-drill holes totaling 435 feet of bore at the McGregor zinc lead mine near Potosi, Washington County, Mo., after the property had been examined by John Soule, an engineer of the Bureau, in the fall of 1942. A small production of lead and barite ore had been maintained at this property for many Years from shallow deposits in residual clays. A few shafts had penetrated the underlying dolomites and exposed a network of narrow fractures containing galena, sphalerite, barite, and marcasite. The drilling by the Bureau tested conditions at depths ranging from 80 to 130 feet. This report sets forth the data resulting from the work.

Jan 1, 1948

By Janet Torma-Krajewski

Job tasks that involve exposure to work-related musculoskeletal disorder (WMSD) risk factors may impact both the risk of injury and production downtime. Common WMSD risks factors associated with mining tasks include forceful exertions, awkward postures, repetitive motion, jolting and jarring, forceful gripping, contact stress, and whole body and segmental vibration. Mining environments that expose workers to temperature/humidity extremes, windy conditions, and slippery and uneven walking surfaces also contribute to injury risk. National Institute for Occupational Safety and Health (NIOSH) researchers worked with powder crew members from the Bridger Coal Company to identify and rank routine work tasks based on perceived exposure to WMSD risk factors. This article presents the process followed to identify tasks that workers believed involved the greatest exposure to risk factors and discusses risk reduction strategies. Specifically, the proposed prill truck design changes addressed cab ingress/egress, loading blast holes, and access to the upper deck of the prill truck.

Jan 1, 2009

This status report contains 39 individual reports on health and safety research projects now being conducted or recently completed by the Bureau of Mines. The Reports on health research cover industrial hygiene, respirable dust, ventilation, noise control, and radiation hazards. The safety research reports cover industrial hazards, ground control, fire and explosion prevention, and methane control. Each report includes background information, a discussion of research progress, and an assessment of each project's current status.

Jan 1, 1979

By William H. King

The Mining Division of the Bureau of Mines has been making development and power-requirement studios for the Interior Department Missouri Basin Field. Committee. The studies by the Bureau of Mines have as their purpose, the summarizing of potential future power requirements in the mineral industry within the Missouri Basin, special emphasis being placed on possible expansion of these requirements through construction of new mining enterprises by private capital. In preparing a proposal for the production of phosphoric acid from phosphate rock near Lander, Wyo., it was found that the basic information on the physical and chemical characteristics of the phosphate beds to determine costs of mining and treatment was lacking.

Jan 1, 1949

By J. B. Clemmer

Fluorspar is one of the most important nonmetallic minerals and is used extensively in the metallurgical, ceramic, cement, and chemical industries. The steel industry consumes most of it, but as the Mineral is the chief source of fluorine, it is becoming increasingly valuable to the chemical industry in the production of fluorine compounds The development of nontoxic organic fluorides for use as refrigerants in mechanical refrigeration and air-conditioning units illustrates the increasing use of fluorspar in the chemical industry. Most domestic flurospar comes from deposits in the Illinois-Kentucky district, which centers around Rosiclare, Ill. About a dozen companies operate in the district, which comprises parts of Pope and Hardin Counties in southern Illinois and Crittenden, Livingston, and Caldwell Counties in western Kentucky. According to the latest available statistics, this district supplied 1/5,960 short tons of fluorspar in 1937, compared with the total domestic production of 181,230 tons. Imports totaled 37,063 tons.

Jan 1, 1939

By W. J. Kroll

This report on the bibliography of zirconium has been confined to those publications and patents that appear to be useful in the commercial development of the metal, both the malleable and the nonmalleable. The methods of production have been stressed and special attention has been given to the alloys. Compounds of importance, like the oxide and chloride, for the manufacture of the metal or of the alloys have been considered. The use of the oxide in refractories anal in the glass and porcelain industries has been omitted. The present survey is critical; that is to say, an attempt has been made to evaluate the effectiveness of suggestions made in the literature. The exhaustive work of Marden and Richy, Bureau of Mines Bulletin 186, published in 1921, has been taken as a base to start from with the intention of bringing the subject up to date with material published in the last 24 years. During this time there was considerable 'advance in the preparation of the metal and Its alloys, and in the development of new uses. On the other hand, there was little progress in the methods of decomposing the ores, so that the chapter on this latter phase is necessarily short.

Jan 1, 1946

By S. H. Ash

For many years the Federal Bureau of Mines has been investigating fires and explosions in mines, tunnels, buildings, and hazardous processes of various kinds. Means and methods for controlling and extinguishing mine fires and preventing explosions and other accidents in many hazardous processes require the collection and analysis of samples of the atmospheres surrounding the sources of ignition. Complex mixtures of gases often encountered in mines, tunnels, and industrial processes may well presage imminent danger from explosions. This report discusses some practicable methods of utilizing the analyses of samples of complex mixtures of gases in their application to the many problems that arise from their presence.

Jan 1, 1948

By Joseph D. Davis

The term "fusain" was first adopted from the French by the American geologist J. J. Stevenson in 1911, according to Wheeler, (1),3 who applies it to that portion of coal resembling charcoal, which he treats as one of the four ingredients of banded bituminous coal. The term has since been adopted by American writers. The Germans use it with slightly different spelling - namely, fusit. It is the equivalent of "mother-of-coal" and "mineral charcoal" of the earlier British writers. The English word fusain is also applied to "a crayon of fine charcoal" and is derived from the Latin root fusus. OCCURRENCE OF FUSAIN IN COAL AND ITS RECOGNITION Fusain is fairly widely distributed in coals of all ranks in varying amounts. It is almost always present in very thin sheets between the bedding planes of the banded coal constituents and presents a jet-black silky appearance who n the coal is split away. As fusain has little cohesive power the coal splits readily along the planes where it occurs. Such fusain bands often attain appreciable thickness -- frequently 1/4 to 3/4 inch. -Beet (2) has reported a maximum thickness of 2 inches for fusain partings, and Sinnatt (3) has found it in the form of plates and lumps; one lump taken by him from the Peacock mine weighed 3-3/4 pounds. Bore (4) has found it in coal balls. Sinnatt (3) states that fusain occurs in two forms, "the first a hard compact variety occurring rather rarely, which can not be pulverized by pressure of the fingers the second type is the common substance" -- that is, a very friable, easily pulverized material. The writer has also found the two types of fusain in the same coal bed and has observed that the hard variety contained considerable calcium carbonate, which probably entered the material in situ by infiltration. Sinnatt further remarks that the layers of fusain (soft type) usually contain less moisture than the coal (or lose it more readily on exposure), and when exposed they quickly change to flocculent powder so that the fines of the coal as mined are likely to contain a major proportion of this substance.

Jan 1, 1929

By J. J. Forbes

The original organic act establishing the Federal Bureau of Mines in 1910 and the amended act of 1913 indicated that promotion of the health and safety of mine workers was to be ore of the chief functions4/ of the Bureau. Many of the field and laboratory studies pursued by the Bureau are designed to improve conditions under dish minors must work. As the Bureau has no legal authority to enforce safety rules, it must rely upon cooperation of employer, employees, State mining or other departments, and labor organizations for success in promulgating its finding and making recommendations. The staff of the Safety Division, which is essentially a service organization of the Bureau, is composed of 28 safety instructors, 29 engineers, 18 clersk, and 7 others engaged in promotion of an educational program in an effort to improve conditions in the mining industry. The work is directed from 14 safety stations in the United States and 1 in Alaska. The work of the personnel, of the mine safety car that operates in. the anthracite region of Pennsylvania was supervised and directed by the district engineer in charge of the Wilkes-Barre (Pa.) Safety Station.

Jan 1, 1940

By H. A. Schrecengost

Information presented herein was gathered by examination of 29 fluidized- bed thermal coal dryers and by conferences with manufacturers and users of such equipment to determine what safety features could be incorporated in design, installation, and operation to minimize fire and explosion hazards. Fire and explosion hazards are inherent in certain types of coal dryers in that high temperatures are employed; the sizes and volatility of material handled are capable of propagating explosions; and drying gases are seldom, if ever, low enough in oxygen content to prevent ignitions of dust clouds, distilled gases, or their combinations. This is especially true for fluidized- bed dryers in which the coal is dried in air suspension and in which atmospheric air is constantly introduced to temper the heated furnace gases. Occurrence of fires on heated bedplates, in dust collectors, and in hot gas inlets was common in nearly all the dryers examined. Forceful explosions which produced external effects had occurred in 11 (39 percent), and internal "puffs" or "bumps" had occurred in at least 24 (79 percent) of the plants examined in the study.

Jan 1, 1965

By H. A. Schrecengost

Information presented herein was gathered by examination of 29 fluidized-bed thermal coal dryers and by conferences with manufacturers and users of such equipment to determine what safety features could b incorporated in design, installation, and op ration to minimize fire and explosion hazards. Fire and explosion hazards are inherent in certain types of coal dryers in that high temperatures are employed; the sizes and volatility of material handled are capable of propagating explosions; and drying gases are seldom, if ever, low enough in oxygen content to prevent ignitions of dust clouds, distilled gases, or their combinations. This is especially true for fluidized-bed dryers in which the coal is dried in air suspension and in which atmospheric air is constantly introduced to temper the heated furnace gases. Occurrence of fires on hated bedplates, in dust collectors, and in hot gas inlets was common in nearly all the dryers examined. Forceful explosions which produced external effects had occurred in 11 (39 percent), and internal "puffs" or ?bumps? had occurred in at least 24 (79 percent) of the plants examined in the study.

Jan 1, 1965

By David White

This paper is the result of a comparative study of ultimate coal analyses made and published by the United States Geological Survey. This study, at first casually undertaken to devise an acceptable classification of coals based on chemical analyses, was continued in connection with a microscopic examination of a number of the coals. The initial comparisons, made from a relatively small number of analyses, not only confirmed a previous conviction that the elimination of oxygen incident to the development of a coal is economically far more important than has been generally suspected, but also showed that oxygen is very nearly as harmful as ash in coal. The immediate purposes of the present study were: (a) To determine more definitely, from a comparative examination of a large number of ultimate analyses, the relative importance of oxygen as an impurity in various coals; (b) to illustrate the transition between various grades of coal of similar origin-transition mainly due to progressive devolatilization, brought about more or less directly by dynamic influences; (c) to ascertain the relative proportions of oxygen, hydrogen, and carbon in coking coals, especially with reference to a theory tentatively framed to explain the coking quality; and (d) to forecast the probabilities of successfully treating a large number of coals so as to render them amenable, in a softened condition, to satisfactory study under the microscope.

Jan 1, 1911

In 1990, the Bureau of Mines (BOM) conducted a mineral investigation of the mines and prospects in the East Mojave National Scenic Area (EMNSA), San Bernardino County, California During field work, BOM identified 701 mines and prospects in EMNSA for which the geology, mineral resources, and mining history were compiled and summarized. Analytical results for 1,188 rock samples collected are tabulated. Total value of identified resources in EMNSA is $5.0 billion. Twenty-four mines and prospects were deemed profitable under current economic conditions. Development could generate considerable economic benefits to San Bernardino County. Potential economic benefits from mining the deposits were evaluated under the following access restrictions for EMNSA: 1) full access, 2) HR 3460, and 3) S 11/HR 780. Under the full access scenario, cumulative mine revenues are $3.0 billion, cumulative personal earnings at mines and supporting industries are $0.94 billion, and annual jobs at mines and supporting industries are 2,379. Under HR 3460, mine revenues, personal earnings, and annual jobs are $2.9 billion, $0.88 billion, and 2,165, respectively. Under S 11/HR 780, mine revenues, personal earnings, and annual jobs are $1.0 billion, $0.32 billion, and 936, respectively.

Jan 1, 1990

By C. A. Geffen-Fowler

This report, sponsored by the Bureau of Mines, presents the results of an examination of the safety of the Blind Shaft Borer (BSB) shaft sinking system and an alternative modified BSB design concept in comparison to conventional shaft sinking technology. Detailed study of the two systems was also performed to identify and recommend design changes for optimum safety conditions. A comparison of the BSB systems with conventional shaft sinking was made on the basis of relative risk levels. Risk incorporates both the frequency and the potential consequence of accidents. A safety evaluation of the component operations of the two BSB systems was performed using a Failure Modes and Effects Analysis (FMEA) methodology. The results of this analysis show generally that both BSB systems are safer than conventional shaft sinking. The potential risk of conventional shaft sinking operations could be reduced by over 30%, on the average, with the use of the original BSB system, and by an average of about 10% with the modified BSB. Design change recommendations to further improve the safety of these systems include better fire suppression systems, improved man haulage systems and more compact hydraulics. An operational safety manual was also developed for the modified BSB system.

Jan 1, 1981

By Wilford S. Wright, Harold E. Heide, Robert L. Thorne, Neal M. Muir, Aner W. Erickson, Bruce I. Thomas

A program of investigation of strategic and critical minerals began in 1940 to examine and develop tungsten occurrences in the western United States and Alaska. During the years in which the nation was at war, this work was given special impetus to stimulate domestic production. This report is a compilation of results of the tungsten investigations in Alaska supplemented by certain data made available by the Territorial Department of Mines and is designed to include in its scope descriptions of all known tungsten occurrences in the Territory. Two areas in Alaska warranted special investigation - one at Gilmore Dome, 16 miles northeast of Fairbanks, and the other in the Hyder District, at the head of Portland Canal. Three tungsten properties - the Stepovich, Colbert, and Yellow Pup - are at Gilmore Dome. The Stepovich property, referred to sometimes as the Cleary Hill tungsten deposit, was worked by the Cleary Hill Mines Co. from April 1942 until May 1944 and was first examined by Robert S. Sanford and Norman Ebbley, Jr., engineers of the Bureau of Mines, in September 1942. The Cleary Hill Mines Co. by that time had explored an 800-foot strike length of the ore zone with 10 bulldozer trenches and was sinking an inclined shaft on ore in the central portion of the explored zone. In January 1943, the senior author, in company with Ebbley and Harry C. Doheny, supervising engineer of R.F.C., examined the property. Preliminary work by the Bureau of Mines began in May 1945, but actual exploration did not commence until late in June and continued until the end of October 1943. The deposit was examined by John B. Mortie, Jr., and William C. Overstreet, of the Federal Geological Survey, in 1942, and this study was continued in 1943 by Frank Byors, who also assisted the Bureau’s engineers on geologic problems. A magnetometer survey of this area was undertaken in 1942 by Henry Joosting and Eskil Anderson, engineers of the Territorial Department of Mines, and was completed with Bureau of Mines assistance in 1943. During 1943 the Bureau completed exploratory projects on the Cleary Hill mine and adjacent Colbert prospect. The field work on the Colbert property was begun early in July 1945 and continued intermittently until the end of October 1943, when it was recessed because of subzero weather. During September 1944, the Bureau of Mines established (by means of a few surface trenches) continuity between the Colbert mineralized zone, high on the dome, and the Yellow Pup vein, the lowest known tungsten mineralization in the area. It is generally recognized that any extensive program to develop the area as a whole logically would be carried out from the lower horizon.

Jun 1, 1948

By R. D. Leitch, J. G. Calverley

"INTRODUCTION Although many investigators have provided information on the strength and other properties of concrete the published literature cites few data on the effect of mixing cement with acid mine waters or on acid resistance of concrete in contact with mine waters. Most of the reported work on the effect of impure waters has dealt with the resistance of cement specimens to ""sulfate waters,"" that is, waters or soils with a relatively high sodium sulfate content. The ""Merriman test"" is used commonly to determine the corrosion resistance of cements for 28 days, but it does not seem certain that a cement having a high sulfate resistance in the Merriman or similar tests necessarily will show correspondingly great resistance to the sulfates of iron and, particularly, to sulfuric acid, which usually are present in acid mine waters. Extensive use of cement mortar for laying up masonry stoppings in coal and other mines and for constructing concrete mine haulageways and shaft linings, coal-storage and other retaining walls, highway bridges, culverts, and many other types of construction where it is difficult to obtain fresh water for mixing or where the structures are later exposed to contact with acid waters makes it important to know the effect of these conditions on cement and whether there is a cement better suited for such work than ordinary portland cement.CONDUCT OF THE INVESTIGATIONFor a short time early in 1935 the opportunity to obtain at least some additional information on the effect of acid mine water on cements was presented by the Relief Works Division, which provided money for irregular and indefinite employment for several months. Purchase of apparatus or material was not permitted under this arrangement, and indefinite duration of the work, intermittent employment, and finally complete cessation of the work prevented planning for extensive investigation of this particular problem."

Jan 1, 1940

By Paul M. Tyler

One of the best present-day yardsticks of the material welfare of a nation is its consumption of minerals, The United States, with only 7 percent of the world population, consumes 45 percent of the world wealth, pays the highest real wages, has the shortest working hours, and numbers the largest percentages of home owners among its population, and at the same time its per-capita consumption of minerals is far greater than that of any other nation. In 1937, British India, with roughly twice the population of the United States, used less than 2 percent as much lead, 4 percent as muck zinc, and 13 percent as much copper; even in Europe, which has three times our population and where war preparations have greatly expanded the normal needs of peaceful industries, the aggregate consumption of metals and industrial minerals other than lignite is less than the total for the United States alone. The march of civilization passed from the Stone Age to the Bronze Age before the dawn of history. It may be questioned whether man or monkey first threw stones at an enemy, but only man could have fashioned rough stones into weapons. Eoliths rudely shaped by apelike men are believed by archaeologists to have antedated by hundreds of thousands of years the existence of our own human ancestors. The primitive people that followed the retreating Ice Cap northward in early quaternary period - at least a million years ago - were fairly adept in the shaping of flints and even used a little copper. The Bronze Age, so-called, superseded the Stone Age when, around 8,000 B. C., the news spread that chunk s of natural copper could be pounded into better weapons or cutting implements than ever could be made by chipping stones. The Bronze Age gave place to the Iron Age about 1,000 B, C., and though students of modern history may speak of the Coal Age, the Petroleum Age, and the Automobile Age, and so on, these ages have all been crowded into a brief century and a half. The truth is that we still are in the Iron Age, unless perhaps we choose to call it the Age of Many Metals.

Jan 1, 1940

By L. B. Berger

Tests and observations of a Diesel-powered locomotive used for under-ground haulage, in a-clay mine were made by representatives-of the Bureau of Mines .primarily to determine the composition of the exhaust gases produced by the engine under actual haulage conditions-and to determine the effects of the operation on the quality of the mine atmosphere. In addition to ascertaining these conditional t proved interesting to analyze the test, data in regard to certain other performance, characteristics of the engine. This report presents results of tests of the mine locomotive, prefaced by a brief resume of the performance characteristics of Diesel engines to facilitate discussion.

Jan 1, 1948

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