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By K. C. Vincent

In the course of, investigation of domestic manganese-mineral occurrences, examining engineers of the Bureau of Mines collected 2-ton lots of ore from properties in the Cleveland-district, Idaho. As only one of the ores was high enough in grade for direct marketing to-producers of ferromanganese, ore-dressing concentration methods were investigated to determine their amenability to treatment. High-grade ore. (38.7 percent Mn) from the Idaho Manganese Mining Co. was taken from a replacement deposit in limestone consisting of several horizontal beds 1 to 5 feet thick, about 1 mile northeast of Cleveland. The manganese minerals occur as an intimate intergrowth of manganese oxides, containing minor amounts of limonite, ?quartz, and calcite as rather fine inclusions. However, the major contaminants are claylike products of rock decomposition, which can be eliminated by thorough washing of the ore at relatively coarse sizes. The Hot Spot property is 1 mile south of Cleveland. The ore occurs as a replacement deposit of medium-grade- ore in limestone, .The sample taken by the Bureau of Mines assayed 26.0 percent Mn. The manganese minerals consist of nodules, principally pyrolusite with some psilomelane and manganite embedded in wad.' The low-grade wad, containing manganese and siliceous minerals in intimate association, was easily rejected by washing.

Jan 1, 1952

By R. W. Watson

In January 1980, the Bureau of Mines initiated an experimental program to examine the fire and explosion hazards of one-hour self-contained self rescuers (SSRs). This action was prompted by a growing concern on the part of government and industrial safety officials over the potential hazards of these devices when deployed on a large scale in underground coal mines. Prior evaluation of the safety of these devices had been at best sporadic and usually limited to experimental models. The recent availability of preproduction models of a l-hour SSR fabricated by the Mine Safety Appliance Company* and a production model manufactured by Dragerwerk Ag Lubeck of the Federal Republic of Germany allowed for a more comprehensive and meaningful evaluation of their safety in underground coal mines. This report summarizes the results of a 5-month study of the potential hazards of these two items. During the course of the work, periodic progress reports were presented to officials of the Mine Safety and Health Administration and various mining organizations including the American Mining Congress, Bituminous Coal Operators of America. National Independent Coal Operators Association, and the United Mine Workers of America. The free exchange of ideas that occurred during these meetings had a significant impact on the direction of this study and a serious attempt was made to address all of the issues that were raised at these meetings. The authors are extremely grateful to the individuals that participated in defining the specific problems that could arise as a result of deploying the self-contained self rescuers in an underground coal mine environment.

Jan 1, 1980

By G. R. FITT, S. R. B. Cooke, C. W. Davis, V. H. Gottschalk, C. G. Maier, C. E. Wood, R. S. Dean, S. B. THOMAS, John Gross, E. P. Barrett, T. L. Joseph

Lack of funds has prevented publication of much of the metallurgical work of the Bureau of Mines during the past 2 years . The present progress report covers studies in the direct production of iron and steel . The experimental work was carried out in cooperation with the universities of California , Minnesota , and Missouri . Complete reports will be published when funds are available .

May 1, 1934

By Thomas A. Phillips

An economic evaluation of the Bureau of Mines process for the separation of raw urban refuse into its metal, mineral, and energy components is presented. The process recovers ferrous metal, mixed nonferrous metals, aluminum, mixed-color glass cullet, and refuse-derived fuel products from raw refuse. Data for this evaluation were obtained from selected runs at the Bureau's pilot plant in Edmonston, Md. A cost estimate was prepared for a plant capable of processing 1,000 tons per day of raw urban refuse operating two shifts, 6 days per week. The fixed capital cost, based on second quarter 1976 equipment costs, is approximately $14.5 million excluding land and shipping containers. The estimated operating cost is approximately $8 per ton of refuse processed. This does not include credit for the products, transportation of the products, a tipping fee, or a dumping fee for wastes produced. No finance charges or taxes are included in the operating costs.

Jan 1, 1977

By A. N. Fried

One of the important problems confronting oil producers in appraising the possibilities of secondary recovery in many California fields is the effect of viscosity on oil recovery by water flooding. In January 1954 there were 554 fields and/or pools, in the State, that produced 1 million barrels daily, and 138 of these pools produced approximately 267 thousand barrels daily of heavy crude oil having gravities below 200 API. Many of these fields are nearing the end of their primary economic life and still have high residual-oil saturations, a favorable factor in water flooding. The crux of the problem is whether or not enough oil can be recovered from these fields by water flooding to make the operation economically successful. Some experiments on the relationship between viscosity and oil recovery have been made by other investigators, but in most instances the viscosity of the oils used in the experiments was lower than the viscosity of the oils found in many of the heavy-oil fields in California. A study was undertaken, therefore, to determine the relationship between oil viscosity and recovery over a wider range of viscosities and to compare the experimental results with those predicted by theoretical calculations.

Jan 1, 1955

By J. A. Kost

A dust-control manual was prepared for use by mine operations personnel. The manual documents state-of-the-art control techniques, dust sampling, and use of personal protective devices. Content addresses advantages/disadvantages of control techniques, design and operating specifications, and implementation and maintenance guidelines. An indexed list of selected references is also included. In addition to the completed manual, this report documents work performed in the course of its preparation.

Jan 1, 1981

Case studies from four western states are used to illustrate the impact of the environmental compliance process on the mining industry. The case studies were not chosen as a statistically significant sample of all mining operations in the western United States but were chosen as representative of operations on both public and private lands and in locations that exhibited varying degrees of involvement by governmental units, non-governmental organizations and the general public. Basically, each case study was chosen because some aspect of their environmental compliance process helped to illustrate an interesting point in the regulatory process. The criteria used to select the case studies were: mines located in different jurisdictional areas, mines located in varying geological areas~ mines located in areas having different historical relationships with mining: and operations that are in production as well as those seeking an operating permit. The variety of such projects should provide the necessary foundation to evaluate the impacts of the environmental compliance process in each location.

Jan 1, 1994

By P. H. Floyd

This report presents the results of laboratory and continuous mill-beneficiation tests conducted at the Bureau of Mines Northwest Electra Development laboratory, Albany, Oreg., on nonsulfide lead ore from the Sherman mine, Leland district, near Burke, Idaho. The predominant lead-bearing mineral in the ore sample treated was pyromorphite, a minor ore mineral of lead. Known reserves of pyromorphite lead ore in the United States are limited, although an appreciable tonnage of this type of ore is found in the Sherman mine. Very little pyromorphite is being mined in this mine or in the United States. This beneficiation problem presented a unique opportunity to study the mineral-dressing properties of a less widely known lead mineral, and consequently adds valuable knowledge to the ways of beneficiating ores containing nonsulfide lead values. This mineral-dressing problem was successful with conventional concentration methods of flotation and Gravity separation.

Jan 1, 1952

By W. W. Adams

The metal and nonmetallic mineral mines (excluding coal mines) of the United States had a more favorable safety record in 1935 than in any year except 1931 and 1932 since annual statistics of accidents first became available in 1911. The accident rate was even lower than that for 1911, when the recorded rate probably did not reflect all of the accidents that actually occurred because many companies had not yet begun to keep complete records of accidents, especially those causing only minor injuries, and when, therefore, the number of accidents revealed by the companies' reports to the Bureau of Mines was probably not as complete as that reported for later years. Compared. with 1911, the accident rate covering fatal and nonfatal injuries in. 1935 decreased 13 percent. Compared with 1925, when the rate was the highest ever reported, the rate for 1935 decreased 47 percent and compared with 1934, 7 percent. The progress in safety which the mines of the country made in 1935 was not confined to any section or mining region; it was shared by a majority of the mining States and applied to underground mining operations, to open-pit mining, and to work at surface shops and yards. The rate for underground mining declined 8 percent from 1934; the rate for open-pit mining declined 14 percent, and that for surface shops and yards 12 percent.

Jan 1, 1938

By James J. Scott

Workshops were held in eight states during the period from December 12. 1975. through June 25, 1976, under U. S. Bureau of Mines Contract to the University of Missouri-Rolla. The workshops were designed to help define the Bureau's research and development priorities. At each workshop a summary of the current Bureau mine reclamation research was presented which was followed by identification of problems associated with mine land reclamation in the state where the meeting was being held. Discussions included the seriousness of problems locally and how the Bureau could best undertake research to assist the state in solving the problems identified. Participants included representatives of state agencies, educational institutions, and companies involved in surface mining. Attendance at these workshops totaled 201 persons who displayed a wide variety of opinions and ideas as to what should be done In government research and development efforts. A breakdown of these attendees is as follows: 91 state and Federal employees; 69 mine operators, equipment manufacturers and consultants; 33 educators and researchers; and 8 others representing such varied interests as environmental and conservation groups, news media and students .

Jan 1, 1976

By James F. Neill, O&apos

Brown iron ore resources in Barbour, Butler, Crenshaw, and Pike Counties were investigated in a drilling program and geological study by the Federal Bureau of Mines in cooperation with the Alabama Geological Survey and the University of Alabama. The aggregate footage drilled was 18,010 linear feet. When developed, reserves of 12,664,000 long tons of crude ore were indicated, containing from 26.9 to 29.0 percent iron and 0.2 to 1.6 percent manganese under a maximum overburden of 40 feet. Total inferred crude ore for the four counties was calculated to be 827,700,000 long tons. Beneficiation of samples by simulated log washing and use of a 118-inch screen yielded from 46.8 to 51.7 percent iron and 0.2 to 2.6 percent manganese. Screen-test studies indicated no appreciable interlocking between the iron and manganese minerals and the waste particles of materials retained on a 200-mesh screen. Clay was prominent in micron-size slimes. Silica was deleterious in the minus 20-mesh size. While an indicated 2,198,000 dry long tons of usable iron ore can be recovered, sink-and-float tests show that it may be possible for 4,654,000 dry long tons to be recovered by other than log washing. However, applicable commercial processes have not been demonstrated.

Jan 1, 1965

By B. F. Naylor, C. H. Shomate, F. S. Boericke

"Ilmenite is the most important titanium-bearing constituent of titaniferous iron ores. Such ores, of which the United States has abundant reserves, are of interest because they constitute an important potential source of both iron and titanium that may be tapped in times of stress, and which eventually may be utilized in the normal course of events.As the iron and titanium constituents of titaniferous iron ores are not completely separable from each other by ore-dressing methods, any process for metal recovery will, of necessity, involve reduction of the iron in ilmenite. Consequently, knowledge of the thermodynamic properties of ilmenite should supplement information already available concerning those ores. With this in view, the Pacific Experiment Station of the Bureau of Mines undertook to evaluate thermodynamic properties; the data obtained are the subject of this report.Three types of experimental work were involved. First, low-temperature specific heats of ilmenite were measured in the temperature range 500 to 29S° K. These data serve to evaluate the entropy, a quantity necessary for a reliable evaluation and correlation of other thermodynamic properties. Second, high-temperature heat-content measurements were made in the temperature range 298° to 1,743° K. The data serve to bridge the gap between room temperature and elevated reduction-process temperatures. Finally, hydrogen-reduction equilibria were measured in the temperature range 1,220° to1,375° K. These data-give a direct measure of the free energy of reduction of ilmonite at these temperatures and, in conjunction with results of the other two types of measurements, serve to obtain the heat of formation of ilmenite, a quantity not readily determinable by direct calorimetric means.The data are correlated to form a composite, self-consistent portrayal of the thermodynamic properties of ilmenite, which may be used in evaluating the efficacy of any reducing agent of known thermodynamic properties. Selective-reduction of iron in ilmenite by hydrogen, carbon monoxide, and carbon are considered in this report."

May 1, 1946

By W. W. Adams, T. D. Lawrence

"The National Safety Competition of 1938, the fourteenth of its kind conducted by the Bureau of Mines in which bronze trophies known as Sentinels of Safety are awarded to winning companies, has just been completed and the results are presented here.With 345 mines and quarries competing, more than in any previous year except 1931, the contest revealed low accident rates at many of the enrolled plants and, which is even more remarkable, it revealed 113 mines and quarries at which no lost-time accidents occurred during the contest year.The Sentinels of Safety trophies, provided by The Explosives Engineer magazine, were awarded to four underground mines, one open-pit mine, and one quarry. Each employee of the winning plant was awarded a Certificate of Honor by the Bureau of Mines in recognition of the employee's part in helping his company to win the trophy. In addition to the award of trophies, a Certificate of Honorable Mention was awarded to each of the mines and quarries in second, third, fourth, and fifth places in their respective contest groups and also to each mine and quarry that worked 30,000 or more man-hours without a lost-time accident. Ninety-two such certificates were awarded for 1938. Twenty-three other mines and quarries also operated without an accident but worked less than 30,000 man-hours, the minimum required by the contest rules for award of Certificates of Honorable Mention.Previous to 1938, five trophies were awarded annually in the National Safety Competition. For the 1938 contest a sixth trophy was provided by The Explosives Engineer so that open-pit mines and quarries, two classes of operations that previously had been included in one group in the competition, might have separate awards."

Aug 1, 1939

By S. B. Christy

This report on the electrodeposition of gold and silver from cyanide solutions represents work that has occupied my time at intervals during the past 20 years. The investigation has been carried on simultaneously with my duties as professor of mining and metallurgy of the University of California. During shis long investigation I have been assisted in the details of the work by, a number of my former students, acting in turn as assistants. Particular mention in this connection is due W. H. Hilton, who graduated in 1900; C. T. Dozier, 1902; N. C. Stines, 1905; H. N. Herrick, 1907, and L. C. Uren, 1911. It is impossible to publish full details of the many thousands of experiments performed. Effort has been made to present only the essential data. Wherever possible, the results of the experiments have been expressed in diagrammatic form by curves showing the relation between the simultaneous variables of the experiments. It is necessary to show, as nearly as may be, the state of the art. This is difficult because of the meager literature on electrodeposition in the cyanide process; hence resort must be had to the specifications and claims of patents, most of which seem never to have been applied on a working scale. Such information consequently can not be taken at its face value. Expressing the essential ideas evolved in such specifications is no easy task. Clearly, in quoting from patent records it is not ·feasible to enumerate all of the specifications or the claims allowed the inventors. A statement of the chief contributions to the art in the patent cited must suffice. Legal details, of course, must be obtained from the original patent. In the study of patent literature, when one compares the ardent hopes of the inventors with the results realized from their efforts, it becomes clear that in the development of an art no one man contributes everything. Each subsequent inventor stands on the shoulders of the one who has gone before. It is only through the summation of the contributions of many inventors that the art as a whole prospers. On October 19, 1887, a British patent was granted to McArthur and Forrest for the use of dilute cyanide solutions for treating gold and silver ores. The rapid extension of this process, in various forms, all over the world, has almost revolutionized the treatment of ores containing precious metals. It is a remarkable fact, however, that long before this patent was granted there was issued, on February 5, 1867, to J. H. Rae, U. S. patent 61866, for an electrocyanide process. Thus a method of electrodeposition from cyanide solutions used for treating ores was invented 20 years before the McArthur and Forrest patent .was granted, although the process did not come into general use. On May 24, 1889, U. S. patent 403202 was granted to McArthur and Forrest for the use of zinc shavings for removing gold and silver from cyanide solutions. The use of finely divided zinc is still the standard method for recovering 'gold and silver from cyanide solutions. Since this patent was granted, many attempts have been made to replace the precipitation upon the zinc by methods of electrodeposition. It is the purpose of this report to give an outline of some of these methods, as well as to show the relative advantages and disadvantages of the zinc and the electrical methods of recovering gold and silver from cyanide solutions.

Jan 1, 1919

By B. J. Moore

This publication contains analyses and related source data for 234 natural gas samples from wells and pipelines in 21 States and 1 foreign country. All of the samples were obtained and analyzed during calendar year 1975 as a part of Bureau of Mines investigations of the occurrences of helium in natural gases of countries with free market economies. This survey has been conducted in the United States by the Bureau of Mines since 1917. In late 1965, the survey was expanded to include foreign gasfields. The analyses published herein were made by mass spectrometer and n special helium analysis apparatus, which are described in Bureau of Mines Bulletins 4862 and 576.3 The results of the investigation of the occurrences of helium are published annually to make the information available as soon as possible to the gas industry and the public in general. Seventeen previous publications have presented the results of 10,831 gas analyses prior to 1975. The first 3, Bulletins 486,4 576,5 and 617,6 contain analyses and related source data on 5,218 gas samples collected from 1917 through 1960. The other 14

Jan 1, 1976

By Lincoln A. Stewart, P. S. Haury

"INTRODUCTION AND RESUME Arizona asbestos mines are the only sources on the American continents of iron-free chrysotile spinning fiber that meets the Navy specifications for asbestos fiber for use in covering electrical cables. Rhodesia normally supplies the bulk of this grade of asbestos at about half the Price of Ari zona spinning fiber. The acute submarine menace in 1942 focused attention on the danger that imports might be cut off and that a sudden demand for greatly expanded production might fall on the Arizona mines to supply the tonnage of this essential material needed for war production.A joint preliminary investigation of Arizona asbestos deposits was made in August 1941 by J. R. Thoenen, senior mining engineer of the Bureau of Mines and A. E. Granger, a geologist of the United States Geological Survey. A more extended investigation of the numerous asbestos mines and prospects, which are scattered over 25 townships of difficult terrain in Gila County, was begun by the senior author in August 1942.The Geological Survey assigned two geologists (Newton Chute and A. F. Shride) a few weeks later to study the geology as an aid in selecting the mines for the Bureau's exploration projects. Six mines were selected for exploratory work because it was desired to prove reserves of ore where production could be started quickly if urgent demand should arise. Acceleration of production is normally slow because of adverse operating conditions. First, the mines are at distances of 35 to 100 miles from Globe, the shipping and supply point, and the roads are few and poor. The mine openings start in steep canyon walls, so that mining supplies usually have to be packed in and the product packed out over 0.5 to 5 miles of burro trail. Second, most of the ore deposits are small, and the ratio of rock broken to spinning fiber recovered is very high, usually exceeding 200."

Aug 1, 1947

By A. W. Fahrenwald

Many factors enter into the efficient operation of the reciprocating type of gravity concentrator. Earlier investigators who studied these factor invariably used natural (crushed ore) products for their experiments, but in the present study synthetic products were used. The variables considered were (1) specific gravity of the sand grains, (2) size of sand drains, and (3) shape of sand grains comprising the table feeds. It is recognized, also, that the percentage relationship of the different kinds of grains is a factor affecting results. This factor is variable in one group of experiments but is thereafter kept constant.

Jan 1, 1929

By G. E. McElroy

Tae purpose of this paper is to present types of charts adapted to aid in the graphic solution of fan-performance problems of selection and operation, and to urge the adoption of similar charts by the National Association of Fan Manufacturers as standard forms for presenting fan-performance data. As matters now stand, it is difficult for the average engineer to solve such problems because a laree number of variables are involved, and performance data are not presented in a manner that permits their direct application to many problems encountered in practice. The performance of any centrifugal machine is determined not only by the machine itself but also by the fluid-flow system on which it operates. Actual performance of centrifugal fans is therefore e matter of the type, size, and speed of fan, on the one hand, and of the relation of pressure to quantity of flow, as determined by the physical condition of the airway system, on the other.

Jan 1, 1936

By G. E. McElroy

[The purpose of this paper is to present type: of charts adapted to aid in the graphic solution of fan-performance problems of selection and operation, and to urge the adoption of similar charts by the National Association of Fan Manufactures as standard forms for presenting fan-performance data. As matters now stand, it is difficult for the average engineer to solve such problems because a large number of variables are involved, and performance data are not presented in a manner that permits their direct application to many problems encountered in practice. The performance of any centrifugal machine is determined not only by the machine itself but also by the fluid-flow system on which it operates. Actual performance of centrifugal fans is therefore a matter of the type, size, and speed of fan, on the one hand, anti of the relation of pressure to quantity of flow, as determined by the physical condition of the airway s: stem, on the other.]

Jan 1, 1936

By H. R. Wells

The Blackbird district, Lemhi County, Idaho, has long been recognized as a potential source of cobalt and copper. However, the comparatively low grade and small size of the known ore bodies, the small demand for cobalt, and. the lack of adequate roads throughout the region precluded extensive exploration of the early discoveries in the area. Recent advances in alloy metallurgy, accentuated by wartime activities, greatly increased the demand for sources of domestic cobalt. Beginning In 1941, engineers of the Bureau of Mines conducted an examination and exploration program in the Blackbird district. This work was supplemented by an exploration program by engineers of the Howe Sound Mining Co., 730 Fifth Ave., New York 19, N.Y.

Jan 1, 1948