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By Thomas M. Barczak, Dennis R. Dolinar, Gabriel S. Esterhuizen

Longwall mines typically use some form of standing support for secondary roof support in longwall tailgate entries. Although there have been several new support products developed for this application, there remains no universal design criteria to optimize the application of these support technologies. The requirement for optimization and proper support selection is to understand the degree of control that the support has on the ground behavior. The ground reaction curve and numerical modeling was used to evaluate the impact of standing support on ground behavior. LaModel was used to evaluate the impact of standing support on main roof and floor behavior and pillar yielding. The conclusion drawn from this study was that standing supports do not have sufficient capacity to control main roof or floor loading or prevent the resulting convergence of the tailgate entry. However, it is imperative that this “uncontrollable convergence” be considered in the support design to prevent premature failure of the support. A FLAC model was used to evaluate the near-seam roof and floor behavior in conjunction with the global vertical and horizontal stresses. The model suggests that standing roof supports can have some impact on the ground behavior as the elastic response of the rock is exceeded and rock structure deteriorates from the stress concentrations that develop around the tailgate opening. During this phase, the capacity and stiffness of the standing support can be critical to the stability of the opening, as eventually the rock mass will be transformed into a partially detached structure whose weight must be supported by the standing support. This work is part of a ground control program of research at the National Institute for Occupational Safety and Health (NIOSH) aimed at improving mine safety by reducing roof fall injuries and fatalities.

By David K. Denton

Results of the mineral resource study of the Upper Priest Lake RARE II study area indicate a low potential for the discovery and economic recovery of silver and lead in the Prichard Formation near contacts with the Kaniksu Batholith in the vicinity of the Mountain Chief Mine (fig. 1). Silver and lead minerals locally occur disseminated and in irregular quartz fissure-fillings in the Prichard Formation. Between 18^6 and 1967, 105 lode raining claims were located in the study area. The area was designated for "further planning" in the Final Environmental statement but was later changed to "nonwilderness" by President Carter after work was scheduled for the area.

Jan 1, 1981

By A. D. Garman

This paper presents one of a series of digests of foreign mining legisla- tion and court, decisions which is being prepared in advance of a general report relative to the right of American citizens to explore for minerals and to own and operate mines in various foreign countries. This interpretation of the laws of Latin America has been prepared from the best available information in Washington, but is released subject to correction and amplification, if necessary, by the proper American diplomatic and consular officers, to whom it is being referred through the courtesy of the Department of State. Individual abstracts of the laws of each of the countries herein discussed have been prepared and published separately. This general summary is presented for the use of mining engineers and investors whose interests extend over the borders of a single country. It is also designed to bring out certain general principles of mining law and, so far as feasible, to indicate the trend of mining legislation in South and Central America. In order to gain perspective, the details of legislation are not com- pletely covered in this paper, but an effort has been made to bring out essential differences as well as points of similarity in the laws of the various countries. The course of legislation is first traced chronologically and the points discussed are then arranged in tables in somerhat greater detail. .Si. With a very few exceptions the existing mining legislation of Spanish America is a development, of the Spanish "Law Decree of Bases" (more briefly referr- ed to as the "Decree-Bases") of 1868. This in turn was influenced, particularly in its classification of minerals, by the French law of April 21, 1810.

Jul 1, 1930

Bitumninous and semianthracite coal reserves underlie about 1,400 square miles of Arkansas, less than 2.7 percent of the state's total area. These deposits, located near the western border, contain an estimated 2.2 billion tons, of which about half are recoverable. This represents less than one-tenth of one percent of the national reserves. Most of the commercial coal is mined from thin beds that are at least 14 inches thick. In some locations, however, the coal beds can be as much as eight feet thick. Lignite was mined in southern Arkansas before the Civil War. Current estimates indicate that the reserves may be as high as 9 billion tons, which could be used in the state's coal-fired electric generating plants; however, these deposits are not being mined at present. Because many coal operations in Arkansas are small and the demand for coal is unsteady, the industry employs fewer than 25 miners on a daily basis. Arkansas gained primacy when its regulatory program was conditionally approved November 21,1980, subject to the correction of four minor program deficiencies. The regulatory program was fully approved January 22, 1982. Authority of the state to administer its Abandoned Mine Land Reclamation Program was granted upon approval of the Arkansas Reclamation Plan on May 2, 1983. Arkansas was the first state to assume responsibility for abandoned mine land emergency projects when its Reclamation Plan was approved.

Jan 1, 1992

By H. M. Smith

The production of oil during the early development of new oil fields is usually accompanied by large quantities of natural gas. Since in most fields gas under pressure is the main source of the energy causing the oil to move through the sands into the wells and thence to the surface, coincident production of natural gas will continue as long as present-day producing methods are used. Generally the use of this gas is restricted, since markets are not readily available. Consequently, a large portion of the gas produced is often wasted by being blown into the air. The magnitude of gas waste is well brought out in the following statement by Miller: Only a few outstanding examples need be cited to show the enormous production of gas that accompanies the discovery of new sources. In April, 1927, the Ventura field produced approximately 210,000,000 cubic feet of gas a day; and during the summer of 1927 Alamitos Heights reached a peak gas production of 102,000,000 cubic feet a day; on December 1, 1928, as a result of the summer's deeper drilling in the Long Beach field, surplus gas production amounted to 125,000,000 cubic feet a day. It is estimated that in January, 1929, the Santa Fe Springs field will have a daily gas production of 387,000,000 cubic feet from the recently discovered Buckbee oil zone. Of this amount 274,000,000 cubic feet a day will be the surplus above the amount required for field and plant fuel, taken out by utility corporations, and that used in repressuring the Meyer sand which lies above the Buckbee zone. Another example of the waste of large volumes of gas is in the Turner Valley field of Canada, 6 where 250,000,000 cubic feet of gas is being burned daily in flambeaus, as there is no present outlet except at prohibitive cost.

Jan 1, 1931

By Charles L. Parsons, R. B. Moore, S. C. Lind, O. C. SCHAEFER

Early in 1912, from information received by the Bureau of Mines, it became evident that quantities of valuable radium-bearing ore from Colorado were being exported for manufacture in foreign coun- trics and that at least part of the manufactured product was being returned to this country and sold at a price entirely incommensurate with that received by the miner and the prospector. Consequently, in line with its efforts to increase efficiency in the mining and treat- ment of mineral resources, the Bureau of Mines undertook an inves- tigation of conditions. Results of this preliminary investigation were published, in the summer of 1913, as Bulletin 70, which gave an out- line of the radium deposits of the West, the conditions of mining, the wastes involved, and the status of the production of radium from its ores. At about this time newspapers and medical journals were publish- ing statements regarding the value of radium in cancer therapy. These reports, although many of them were exaggerated, brought out clearly the remarkable virtue of the gamma rays for the treat- ment of cancer and other malignant growths. In view of the fact that the largest known supplies of radium ore in the world are in the States of Colorado and Utah and on the public lands of the United States, it was deemed highly important for the Bureau of Mines to study the production of radium in detail. Such study, it was hoped, would enable the prospector and miner to obtain a fairer price for the ores and would furnish information necessary in case Congress appropriated funds to develop methods for extracting radium from ore on the public lands under Government supervision, to be supplied at cost to the hospitals of the Army, Navy, and Public Health Service.

Jan 1, 1915

By William R. Vogel

The Bureau of Mines Information and Analysis organization collects worldwide data on virtually every commercially important nonfuel mineral commodity. These data form the base for tracking and assessing the health of the minerals sector of the U.S. economy. This data collection activity was instituted by the 47th Congress in an appropriations act of August 7, 1882 (22 Stat. 3291, to place the collection of mineral statistics on an annual basis. The most recent authority for the Bureau of Mines Information and Analysis activity is the National Materials and Minerals Policy, Research and Development Act of 1980 (Public Law 96-479, 96th Congress), which strengthens protection for proprietary data provided to the U.S. Department of the Interior by persons or firms engaged in any phase of mineral or mineral- material production or consumption.

Jan 1, 1989

By P. M. Ambrose

This report describes an accident, which took place in the Chemical Corrosion Laboratory at the College Park, Md., Station of the Federal Bureau of Mines. The accident occurred while Walter L. Acherman, chemist, was performing a routine manipulation during a corrosion experiment involving commercially pure titanium and red-fuming nitric acid. There was a sudden and very violent reaction, and a large quantity of acid was thrown in the face and over the body of Acherman, causing serious injury. L. B. Golden, chief of the Chemical Corrosion Section, was exposed to nitric acid fumes during the ensuing rescue and first-aid operations and died on January 25, 1954. According to the medical report, the direct cause of Mr. Golden's death was pulmonary edema and confluent bronchopneumonia; the contributary cause, was inhalation of fumes from red fuming nitric acid. The following employees of the College Park Station contributed to this report by supplying information on the accident and assisted in the rescue operation: L. B. Golden, chief, Chemical Corrosion Section; T. E. Green, chemist; Robert Warf field, chemist; L. A. DeVivo, laboratory mechanic; D. W. Chalkley, laboratory mechanic; E. H. Neagle, laboratory welder; and R. L. Heath, laboratory general mechanic.

Jan 1, 1955

By Floyd G. Anderson

This report reviews and summarizes information on prevention and suppression of dust in mining, tunneling, and quarrying published in the United States during the years 1958 through 1960. Unpublished pertinent data developed or assembled by the Bureau of Mines during this period also are included. Silicosis statistics reported by the U.S. Public Health Service indicate a sizable silicotic population in the United States and suggest a need for greater dust-control effort. A joint medical-environmental survey was begun by the U.S. Public Health Service and the Bureau of Mines to evaluate the magnitude of the silicosis problem in the metal mining industry in the United States.

Jan 1, 1962

By Robert D. Perry

This report describes methods of reclaiming abandoned or inactive tailings ponds and dams. The investigated sites were selected tailings deposits adjacent to metal mines in the southwestern United States and the Pacific Northwest. The basic data developed for each site consisted of the following: a review of existing literature; a site visit that included sampling of the tailings and surrounding materials; laboratory and engineering studies; and development of reclamation plans. Laboratory tests determined the gold and silver content of each tailings deposit and the chemistry of the tailings and surrounding materials. Reclamation plans that include approximate costs were developed for five tailings deposit sites. These ranged in size from 52,000 to 103,000,000 tons. Our conclusions on the remining potential of each site are based on the tailings assay and other technical data. This study concludes that remining as a reclamation tool is feasible at certain sites. Included in this report is a remining program as part of the overall reclamation plan for two sites. Our preliminary results indicate that remining as a reclamation tool is feasible for only one of them.

Jan 1, 1981

An examination of the Census of Fatal Occupational Injuries (CFOI) data for the period 1992-1995 shows that 659 fatalities occurred in the mining industry as defined by the SIC. Oil and gas accounted for slightly more than one-half of all fatalities (figure 1-1). The coal industry had the highest fatality rate for the 4-year period, with 35.6 deaths per 100,000 full-time workers, followed by metal (23.1 per 100,000), oil and gas (23.1 per 100,000), and nonmetal (20.1 per 100,000). The fatality rate for all U. S. industries during this same period was 5.1 per 100,000 full-time workers. Figure 1-2 compares the fatal injury rates by year for the four major industry sectors of mining to the fatality rate for all industries combined. Figure 1-3 compares age-specific fatality rates in the mining industry to those seen for U. S. industry as a whole. Fatality rates for all industries combined were lowest for young workers and steadily increased in relation to workers' ages. In the mining industry, fatality rates by age group show a U-shaped curve. Young workers under 20 years of age had the highest injury rate (54.6 per 100,000), followed by workers aged 20-24 (50.8 per 100,000) and workers over age 65 (37.7 per 100,000). Table 1-1 shows the distribution of injuries by type of injury event. The mining industry, in comparison with all industries, had a considerably larger proportion of fatalities classified as caught in or crushed by collapsing materials (9.1% and 1.9%, respectively) and fires and explosions (10.0% and 3.1%, respectively). Transportation events comprised the largest proportion of fatal injuries in both the mining industry and all industries. Within the mining industry only, transportation accounted for the largest proportion of fatalities in all mining sectors except coal. A more detailed examination of the transportation events within the mining industry showed that highway incidents (50.5%) were the most common, followed by nonhighway incidents (22.2%), pedestrian incidents (10.6%), and those incurred during rail, water, and air transport (15.7%). Incidents involving caught in or crushed by collapsing materials comprised a higher percentage of injuries in the coal and metal sectors, while fall-from-height incidents were more frequent in the oil and gas sector. The classification system used in CFOI for type of injury event is not compatible with any variables contained in the MSHA data; therefore, direct comparisons are not attempted. [ ]

Jan 5, 2000

By Ren G. Dong, Richard McCormick, Dan E. Welcome

Vibration exposure at workplaces is generally multi-axial. The health effects of vibration exposure also likely depend on the vibration direction. Therefore, there is a wide interest in the simulation of multi-axial vibration in laboratory experiments. Advances in technology have led to the development of a new 3-D test system for studying hand-transmitted vibration exposure and health effects. The purposes of this paper are to introduce the system and to present the results of its preliminary evaluations. Test System As shown in Figure 1, the system is basically composed of three vibration generators, a multi-axis vibration control system, instrumented handle, handle fixture, and shaker-fixture linkages (stingers). [ ] Figure 2 shows the array of three vibration generators (MB Dynamics, Energizer BLACK-500 lbs) and their associated support bases and foundation developed by MB Dynamics (Cleveland, USA), which create the 3-axis simultaneous motion. These electrodynamic exciters are powered by power amplifiers which provide current proportional to the analog drive signal from a controller. The controller (JAGUAR Multi-Input/Multi-Output closed-loop vibration controller) was provided by Spectral Dynamics, San Jose, California, USA). NIOSH-designed instrumented handle was equipped on the system.

Jan 6, 2006

By James H. Russell

The Bureau of Mines used a statistical approach to evaluate the effects of temperature, current density, and composition of the electrolyte on the purity of boron prepared by electrolysis of a fused mixture of boric oxide in potassium fluoborate. The quadratic equation which best fits the data was calculated for a temperature of 650° to 850° C, a cathode current density of 40 to 1,150 amp/ft2,and a boric oxide content of 0.3 to 7.1 molal. The best products, better than 95 percent boron, were obtained when the current density was less than 2 amp/ft2 and the boric oxide content was less than 2 molal.

Jan 1, 1967

Approximately half of all the fuel energy used in the United states is now pro-vided by oil and natural gas. A persistent and rapid growth in energy demand during the last 3 decades has been absorbed largely by the liquid and gaseous rather than solid fuels. In 1948 the energy provided by coal was substantially the same as in 1920. Meanwhile, the use of oil and natural gas each had increased fivefold. On a per capita basis, the change is more significant. Coal consumption has dropped from about 6 tons per person to 4-1/2 tons, while oil has increased from 4-1/3 barrels to 14-1/3, and natural gas from 7,500 cubic feet to about 35,000. These facts would have only academic interest if the United States had unlimited supplies of all fuels. However, while the Nation's reserves of coal are adequate to meet our needs for centuries, those of oil and natural gas appear limited. It is obvious, therefore, that the security of our liquid-fuel position would be greatly enhanced if the supply could be based in an increasing degree on solid fuels, such as coal and oil shale, which make up more than 95 percent of our fuel reserves, instead of natural oil and gas. In addition, this would create new employment and help to stabilize the market for coal, which may be facing comparatively bleak prospects in the near future unless its position with respect to other fuels is improved.

Jan 1, 1950

By BUREAU OF MINES

This report is submitted in accordance with the provisions of the Synthetic Liquid Fuels Act of April 5, 1944 (30 U.S C. 321-325, as amended), which require that: "The Secretary of the Interior shall render to Congress on or before the first day of January of each year a report on all operations under this Act." Owing to the broad scope of the content and the diversity of interests represented, the Annual Report for 1953 has been divided into two separate publications. Each has been published by the Bureau of Mines as a Report of Investigations, and the respective titles follow: R. I. 5043, Part I - 011 From Coal. R. I. 5044, Part II 011 From 011 Shale. - Identical in each report, the introduction summarizes research progress made in 1953 under the entire Synthetic Liquid Fuels program. A free copy of each of these publications may be obtained by a written request to the Bureau of Mines, Publications Distribution Section, 4800 Forbes Street, Pittsburgh 13, Pa. The R. I. number and title of the publication desired should be indicated.

Apr 1, 1954

By Steven J. Page, John A. Organiscak

Laboratory crushing experiments were conducted on a range of low- to high-volatile bituminous coals to investigate the various factors influencing airborne respirable dust (ARD) generation. This research was conducted to identify the principles of ARD liberation from the coal product. Five U.S. bituminous coals were uniformly prepared and processed through a double roll crusher located in a low-velocity wind tunnel. Experimental factors studied included inherent coal seam constituents, coal grind ability, specific energy of crushing, product size characteristics, dust cloud electrostatic field, and specific ARD generated. The results of this investigation indicate that a combination of several factors are associated with ARD generation. One factor is the effect of coal rank, described by the inherent moist fuel ratio, on the product size characteristics, defined by Schuhmann size function parameters. Another key factor is the effect of air dry loss(ADL) moisture in the coal seam on the breakage-induced electrostatic field of airborne dust. The effect of these factors is that different percentages of <10-m coal particles are dispersed as ARD. A discussion of electrostatic field principles, coal ADL, and its effect on ARD generation is presented.

Jan 10, 1998

By W. D. Riley

The Bureau of Mines is conducting research on methods for the rapid identification and sorting of mixed scrap metals and alloys so that domestic scrap resources can be fully utilized. One method, spark testing, is the examination of the pattern of sparks that results when a metal or alloy is ground on an abrasive wheel. This technique requires experienced sorters. Bureau researchers have shown that spectrophotometric methods can be used in lieu of the highly skilled sorter. The spectra of a mild steel, an HSLA steel, several stainless steels, and four nickel-base alloys have been measured. Differences in the spectra that are sufficient for identification are apparent.

Jan 1, 1985

By Warren D. Longwill

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Jan 1, 1981

In 2001, 14,623 mining operations reported employment statistics to the Mine Safety and Health Administration (MSHA). This was an increase of 210 mining operations compared to 2000. Almost half (49%) were sand and gravel mines, followed by stone (29%), coal (15%), nonmetal mines (5%), and metal mines (2%).

May 1, 2003

By Roger M. Sherman

[Investigation of mine land characteristics, evaluation of irrigation systems, and evaluations by the mining industry, determined that irrigation is a feasible method for aiding revegetation of coal mined lands in western arid and semi-arid regions. The various regions studied displayed a commonality of characteristics which enables, independent of the site or region, the recommendation of solid set irrigation. Irrigation should be supplemental by complimenting natural precipitation and be should implemented on a temporary basis.]

Jan 1, 1980