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By Thomas Gales

Longwall mining has a high potential for producing bulk production from a single face. Production is interrupted for a considerable time when it is necessary to move the equipment to a new block of coal. The frequency of such moves can be reduced by increasing the dimension of the block to be moved. Merely doubling the tonnage in a block to be mined may increase production by more than 21,000 tons per year. The time taken to move the equipment can be reduced by careful preplanning, industrial engineering analysis, and specially designed equipment. Reducing its move time from 30 days to five days can increase production by more than 25,000 tons per year. Increasing the panel dimensions and reducing the move time can give an increase in pretax profits of more than $600,000. A comprehensive bibliography is included.

Jan 1, 1977

By D. Harrington

When the word "gas"' is mentioned in connection with mining almost invariably it is inferred that the explosive gas, methane, is in mind and that the reference is to coal mining. Although methane is likely to occur in any coal mine the metal mines of the world contain by far a greater variety of gases than do the coal mines. Often the gases in metal mines are as dangerous as the gases likely to be found in coal mines, and sometimes are even more deadly. A coal mine is more likely to contain methane than a metal mine. In rare instances it may contain high percentages of nitrogen or carbon dioxide or it may be deficient in oxygen where the air is confined in a blind end or in a sealed region. Much more rarely relatively small percentages of ethane or other hydrocarbons with an odor of ether, gasoline, or kerosene, or minute percentages of hydrogen sulphide are found in a coal mine. During a coal-mine fire or explosion carbon monoxide content is likely to be high (4 per cent or more), and if the coal contains much sulphur the high fumes may contain some sulphur dioxide.

Jan 1, 1931

By James Westfield

This report covers the calendar year 1953 and has been prepared and submitted in accordance with the provisions of Sec. 106(a) and Sec. 212(c) of the Federal Coal Mine Safety Act (66 Stat. 692; 30 U.S.C. Secs. 451-483). During this first full calendar year of operations under the Federal Coal Mine Safety Act, the coal-mining industry of the United States attained the best injury records in its history - improving the former best records (made in 1952) by 91 fatal and 10,020 nonfatal injuries. Whereas, the mandatory provisions of the act were intended and designed to prevent major mine disasters, apparently the effects have reached beyond the scope thereof in reducing mine accidents generally.

Jan 1, 1954

By Ernest A. Curth

Statistics For 1956-66 show that mine transportation accidents accounted for 19 percent of fatalities in bituminous coal mines, second only to roof deficiencies as a cause of death. Productivity per man-shift increased from 10.2 tons in 1956 to 18.4 tons in 1966, but the fatalities per million man- hours of exposure also increased from 0.19 to 0.21 during that same period, indicating that transportation hazards still persist. Consequently, the Bureau of Mines reviewed the transportation fatalities that occurred in bituminous coal mines during 1956-66. The data were processed by computer to find what constitute hazardous conditions and unsafe actions as well as to correlate occupation and age of victims, transportation type, and mine production. Environmental factors and equipment defects which create hazards, as well as unsafe actions of personnel, were determined for each type of mine transportation: Track haulage, mobile nonrail haulage, conveyors, hoists, automotive operations, and front -end loaders, and for transfer stations (loading points, slope and shaft bottoms, surface transfers) and railroad yards. Man-trip accidents, a group with a catastrophe potential, also were analyzed. The basic design and operational features of each transportation type were outlined and procedures considered safe in the light of accident experience were suggested. Findings show that unsafe actions of personnel and hazards created by environmental deficiencies or equipment malfunctions contribute equally in causing transportation accidents. Accordingly efforts should be directed toward improving working conditions, equipment maintenance, and education and training of employees. The trend is toward using safer modes of transportation, notably conveyors. More attention should be given to track haulage operation, railroad yards, and nondestructive field testing of materials.

Jan 1, 1971

By S. L. Windes

"INTRODUCTION For a number of years, the Bureau of Mines conducted tests on various types of structures to ascertain the effect of seismic vibrations emanating from quarry blasting in an effort to determine an index of damage. Associat¬ed with these tests, occasional records were made of the characteristics of the air blast or concussion from the explosions. Although the importance of the air-blast problem was recognized, the equipment was not designed for airblast measurements, nor was the early research program concerned with the problem. After the ground-vibration tests had been completed, attention was turned to study of the air blast and its effect. The program was modified, however, in certain aspects by the imminence of war and the final entry of the United States into the conflict. These modifications were made to supply information pertaining to military and civilian defense problems.Detailed discussion of these problems is beyond the scope of this report, which attempts to present preliminary results of factual and fundamental character. However, it may be noted that airblast data are urgently needed for intelligent design of both Government and non-Government buildings, which must withstand the air blast from bombs and afford maximum protection for the occupants. The safety of vital equipment above and below ground necessitates consideration of damage from air blast. Protection against use of dynamite by saboteurs, moreover, hinges largely on the effect of air blast. Identification of a planned ""accident"" involving dynamite often entails knowledge of the characteristics and power of the airblast.The peacetime problem of damage from air blast resulting from quarry and mining blasting activities is of course exaggerated by the wartime requirements of increased production accelerated operation, and enlarged development."

Jun 1, 1943

By CHARLES L. WRIGHT

Coals may be divided into six classes-anthracite, semi anthracite, semibituminous, bituminous, subbituminous, and lignite. The first three cla~ can be distinguished by dHferences of composition, particularly the proportions of fixed carbon and the ratios of the fixed carbon to the volatile matter in the cools. The last three classes can be distinguished by di:fferences in physical character, chiefly in color and in manner of weathering. Lignite is brown, not black, and has generally a woody look, but it weathers in much the same way as subbituminous coals. On exposure to the air lignite slacks or crumbles. The lumps check and fall into small irregular pieces that exhibit a decided tendency to separate into extremely thin plates. Hence lignite deteriorates greatly during storage or long transportation. The most characteristic feature of the composition of lignite is a large percentage of moisture. '!his high moisture content reduces the fuel value of freshly mined lignite, and the partial evaporation of moisture, on expooure, causes th6 fuel to check and fall to pieces. Consequently, attempts to increase the efficiency of lignite as a fuel involve reducing its percentage of moisture and increasing its ability to endure storage and transportation. Both these results are accomplished by briquetting.

Jan 1, 1911

By Daniel Harrington

For several years the United States Bureau of Mines has been making a study of ventilation in metal mines, this study covering practically all the important mining districts of the country. One of the districts where a close and extended study was made was that of Butte, Mont., with its numerous interesting problems and conditions. In February, 1916, Daniel Harrington, mining engineer of the United States Bureau of Mines, was detailed to investigate the circumstances surrounding the death of 21 men in the fire at the Pennsylvania mine at Butte, and during that investigation he made underground visits to several of the large mines through the courtesy of the mine operators, and became much interested in the ventilation conditions. In May, 1916, Mr. Harrington was detailed te work in cooperation with Dr. A. J. Lanza of the United States Public Health Service in an investigation of the prevalence and causes of miners' consumption in the district. This work broadened so much that the investigation was not completed until late in 1918, the investigators making a detailed inspection of all working places in four large mines and a more or less extended examination of conditions in about 20 other mines. Ventilation was recognized immediately as being an important factor in the health of miners, and from the outset of the investigation a large part of the work consisted in obtaining and compiling data relative to the flow of air, humidity, and temperature. The officialsof the North Butte mine were engaged in making a study of ventilation problems before the coming of the investigators, so that opportunity was given to work with those officials for several months. Detailed data on air flow, temperatures, humidities, and an analyses had been obtained before the fire in the North Butte mine June 8, 1917, which resulted in the loss of 163 lives. Much information was obtained during the progress of the fire, and a detailed examination was conducted after the fire, hence an exceptional opportunity existed to study conditions relating to ventilation. This bulletin is a result of studies made from the data collected during the two and one-half years of study and observation a-boveoutlined. Its publication has been delayed through lack of funds for printing. Other publications relative to metal mine ventilation -in other parts of the United States are expected to follow.

Jan 1, 1923

By John G. Parker

The rare-earth elements, sometimes known as the lanthanides, comprise the series of 15 chemically similar elements with atomic numbers 57 through 71. Yttrium, with atomic number 39, is often included in the group, because its properties are similar and it more often than not occurs in association with the lanthanides. Thorium is included in this survey due to its close association with the lanthanides, particularly in the mineral monazite. The lanthanides were first recognized as elements around 1750 and were the subject of much study by chemists during the 19th century. The purely chemical methods then available failed to resolve the strange intimate relationships between these elements, and it was not until about 1920 that the full series was explained.

Jan 1, 1971

1. Domestic Production and Use: In 1980, 13 companies operated 33 primary aluminum reduction plants, with 3 firms accounting for 62% of production. Washington, Oregon, and Montana accounted for 30% of the total production; Texas, Louisiana, and Arkansas 19%; Tennessee, Alabama, and North Carolina 15%; other central and eastern States 36%. Based on published producer prices output of primary metal in 1980 was valued at over $7 billion. Aluminum consumption by 25,000 firms was centered in the East Central United States. Packaging accounted for an estimated 26% of domestic consumption in 1980, building 22%, transportation 21%, electrical 12%, consumer durables 7%, and other uses 12%.

Jan 1, 1981

By K. C. Dean

Discarded automobiles represent the greatest single resource of reusable metals, plastics, and rubber in the United States. This report presents results of Bureau of Mines research, conducted from 1965 to 1983, on separating and recovering useful materials from the scrapped hulks, using old and new metallurgical techniques combined with standard scrapyard methods. The Bureau determined the materials composition of three composite cars designated as circa 1960, mid-1970's, and early 1980's, and used these cars to study smokeless incineration and hand-sorting techniques. In studies on treating rejects from automobile shredders, the Bureau designed a process that included air classification, water elutriation, magnetic separation, handpicking, and heavy-medium separation, and also investigated cryogenics and liquation. Complete recovery of cop-per and other metals was economically made by hand and tool dismantling, leaching, or selective melting of starters and generators. Techniques are also discussed for plastic recovery and waste tire treatment.

Jan 1, 1985

By Charles Enzian, Donald F. MacDonald

It is a far cry from the small and uncertain mining efforts of 50 years ago to the splendidly equipped and solidly financed organiza- tions that now handle thousands of tons of ore per day. The old mining was largely speculative; the new is practically on a manu- facturing basis. In the old days of mining the aim was, chiefly, to find comparatively rich ore; modern practice looks more toward efficiency in mining and milling, so that vast tonnages of low-grade material may be worked at a profit. The old operators had faith and hoped for good returns; the new ascertain with a fair degree of precision what the available tonnage is, what the cost of mining and treating the ore will be, the time necessary to exhaust the deposit, the capital required, and the net profits to be made. The old mining was financed on a highly speculative basis, and the value of mining stock was largely controlled by the imaginations of the promoters and of the individual holders. In the new régime the financing of mines is often as conservative as the financing of manufactures or railroads, and the value of stock, quoted on the leading exchanges, is controlled by the carefully estimated profits in sight. Of course, with every legitimate industrial enterprise go certain business risks, and mining is not exempted from these. Then, too, valueless mining as well as valueless industrial stocks are sometimes offered for sale by the intentionally dishonest, or the ignorant. However, the prospective purchaser of a mine nowadays, if he is willing to pay for the services of reputable mining engineers, can obtain information on which to base an opinion as to the quality of his investment. The relatively recent development of cheap and efficient methods of mining and of ore dressing has given value to low-grade ore bodies that a few years ago were almost valueless. The iron mines of northern Minnesota have been fruitful in developing efficiency in mining methods, notably the open-cut methods in which steam shovels strip off the overburden and then load the ore directly into railroad trains for transport to the furnace. In 1907 open-cut mining was applied to the low-grade copper ores of Bingham, Utah, with splendid results, and since then it has won a most important place in the min- ing of large masses of low-grade ores in several other mining regions, especially at Santa Rita, N. Mex.

Jan 1, 1916

By G. B. Shea

In 192b, there wore 47 fatal accidents in the California petroleum industry, 14.6 per cent more than occurred in 1927 when 41 men lost their lives in the drilling, producing, manufacturing, and marketing divisions of the industry. This increase in the number of fatal accidents for 1928 has caused the first upward trend in the fatality curve of the California petroleum industry since 1923. In no other year during the 6-year period have the fatalities in any one year been greater than those for the preceding year. This fact should be given serious consideration and study by the petroleum industry, and an endeavor should be made to cause the number of fatalities again to decrease and conform to the previous gradual declining trend of the fatality curve. The following chart shows the trend of fatal accidents during the past six years:

Jan 1, 1929

By W. C. Holliman

Commercial production of synthetic rubber in the United States became a reality in 1931 when E. I. duPont de Nemours, Inc., announced the manufacture of Duprene, a synthetic rubber made by polymerizing r chloroprene. Duprene was later improved and reintroduced as neoprene. Since 1931 other synthetic rubbers and rubberlike materials have been announced and are now produced commercially or are in the pilot-plant stage in the United States. These include Thiokol, Buna S, Perbunan, Koroseal, Vistanex, Flamenol, Ameripol or Hycar, Chemigum, Butyl rubber, and Flexon. None of these is synthetic rubber in the strict chemical meaning of the word synthetic, as none is identical in chemical structure with natural rubber. However, all possess some of the physical properties of natural rubber, and in addition usually have some outstanding property not found in natural rubber that makes them superior for certain uses. Because of these superior qualitites, a considerable demand had arisen for synthetic rubbers before the present emer¬gency, although the price was several times that of natural rubber.

Jan 1, 1943

By A. J. Kraemer

This report on research and experimentation by the Federal Bureau of Mines on technologic and scientific problems of the petroleum and natural gas industries presents a resume of work from July 1, 1953, to June 30, 1956. The preceding report, for the fiscal year ended June 30, 1953,3/ indicated continuation of the Bureau's program of petroleum and natural gas research of world-wide significance, which began in 1910. The petroleum and natural gas research of the Bureau of Mines is divided into five main categories: (1) Production of petroleum and natural gas, (2) transportation and storage, (3) petroleum chemistry and refining, (4) thermodynamics, and (5) economics.

Jan 1, 1959

By Eldon C. Pattee

THE BUREAU OF MINES began an investigation of tungsten resources of Montana in September 1953. This report presents information obtained from July 1955 to September 1957 on tungsten deposits in and near the Mount Torrey batholith. The batholith comprises part of the Pioneer Mountains of Beaverhead County in the southwest corner of Montana. Included in the report are assays and preliminary-examination data on 22 properties. Tungsten minerals are known to occur in 19 of the properties. The major producer is the Brown's Lake mine which has produced more than 625,000 tons of ore. Nearly all of the deposits are in the Lost Creek, Utopia, and Bald Mountain mining districts along the east and south margins of the Pioneer Mountains. The districts are less than 27 miles from Dillon, Mont.

Jan 1, 1960

By W. W. Adams

[The s1xteeilth an.nual National Safety C mpeti t1on, concluc ted "by the Bureau of t4ine g, Un+ ~ed st tag' DepartIilent 0:1' the Interior, has jast been closed, and the results reveal t:'W.t. t_!e co~)eting comps.nies had fewer a.ccidents in proportion to the number. of !\1a..."1-h(J1J.l'~ :orkcd than in a:ny other yeex in the record of the contest. These annUk~l contestn are thus achieving the r purpose of promoting safety in tho minin induC'tr:r. ]

Jan 1, 1941

By W. M. Traver

During World War II, the Bureau of Mines investigated a large number of ore deposits in the United States and Alaska in a search for domestic sources of strategic minerals. Deposits chosen for exploration included those expected to contain metals of importance in the successful prosecution of the war. This report describes exploration of a district of known antimony occurrence on Coyote or Antimony Creek near Antimony, Garfield County, Utah. A preliminary report by Paul T. Allsman, Chief of the Bureau's Salt Lake City branch made in August 1941, recommended further investigation, and proposed methods for performing the work. The project, begun in November 1941 and completed in January 1942, included trenching and sampling in four of the most promising parts of the area The Federal Geological Survey cooperated in the work by detailed mapping and assisted in the interpretation of geologic data.

Jan 1, 1949

This Kaiser Engineers report on the feasibility of surface mining on the North Slope of Alaska has considered the quantity and quality of the North Slope deposits with attention paid to the economic, technical, and environmental constraints of the mining systems suggested for the three candidate minesites at Kukpowruk River, Elusive Creek, and Kuk River. Site selection, based on coal rank and quality as well as seam thickness and geometry, also considered demonstrated and hypothetical reserves relative to three mining systems (dragline, shovel, dragline and shovel), mining equipment requirements, infrastructure, and transportation relative to the Arctic environment and costed for potential markets. Throughout the report the delicate permafrost environment has received particular consideration. Recommendations based on the technical, economic, and environmental feasibility of mining the coal deposits of Northern Alaska by surface mining techniques have resulted in two conclusions: 1. The coal deposits can be mined with currently available technology; 2. It is uneconomic to mine these coals given current coal resource estimates, costs, and market conditions. A literature survey is included in appendix.

Jan 1, 1977

By Robert H. Peters

This U.S. Bureau of Mines report identifies the types of serious accidents that occur most frequently at small underground coal mines and describes the strategies that could help prevent these accidents. A wide variety of methods for improving safety are suggested, including improvements in the design of equipment, work procedures, work schedules, safety programs, and emergency response plans, as well as techniques for diagnosing the potential hazards associated with new technologies and work procedures. Some of the papers in this volume focus on preventing specific types of mining accidents-ones associated with materials handling (primarily back injuries), equipment maintenance, improper machine guarding, and ground failure during retreat mining. Although the recommendations in this volume are heavily influenced by research performed at underground coal mines in the Appalachian coalfields, most of the papers contain advice that is equally pertinent to almost any type of mine.

Jan 1, 1994

By Herbert Haas

The Bureau of Mines is endeavoring to reduce waste and increase efficiency in the production, refining, and utilization of petroleum . During the last few years the demand for petroleum and its products has increased so much more rapidly than the production that greater efficiency in utilization is now a matter of most serious importance . The Diesel engine, a comparatively new type of internal-combus- ' tion engine, is an important device for insuring more efficient utilization of petroleum and coal-tar products, for it consumes heavy liquid fuels such as can not be utilized in other types. Like the gas or the gasoline engine, it is revolutionary within its province. For some uses this engine is replacing gas and gasoline engines , but its most important duty will be to replace the wasteful consumption of fuel oil in steam engines. Not only will a wider use of the Diesel engine relieve the demand, but it will result in more power being obtained from the same consumption of fuel oils . In spite of these advantages, comparatively few Diesel engines are in use in the United States . In this report the author discusses recent developments in the design and construction of the Diesel engine, the fuels suitable for burning in it, and the uses to which it is particularly adapted .

Jan 1, 1918