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By E. P. Youngman

The mining laws referred to by those who furnished the reports mentioned in the preceding paragraph are : General Austrian Mining Law of 1854 and the Law of 1868 , which prescribes for Hungary (as well as for Transylvania ) the full text and decisions of the General Austrian Mining Law; Government Decree 18346 , 1859 ; Parliamentary Decree of 1861 ; the Law of 1871 ; the Commercial Code , Law 37 of 1875 ; the Industrial Lar of 1884 ; the Law of 1386 ; the Decree of the High Court of Justice , 5540 , of 1399 ; Laws 6 and 7 of 1911 ; Law of 1921 ; Laws 23 and 24 of 1922 ; Laws 5 and 21 of 1927 ; and Law 40 of 1928. ( Lev 21 of 1927 and Law 40 of 1928 are labor laws . ) A compilation of the mining laws of Hungary , " Magyar Banya Jog , " or the " Hungarian Mining Law, " was made use of in part . This volume is the second edition of a school textbook , which ras prepared by Dr. Bela Balkay and Dr. Imre Szeoke , and which was published by the Apollo Press ( V. , Sas -utca 13 , Budapest ) in 1909 .

Jun 1, 1931

By Thomas C. Ruhe

The Bureau of Mines conducted research to determine the safe operating conditions for using recycled (used) lubricating oil from mining equipment as a partial replacement for diesel fuel to make ANFO-type blasting agents. The use of recycled oil (RO) saves energy, reduces oil imports, and reduces mining costs. Low ambient temperatures may cause these recycled oils to become too viscous for proper absorption by ammonium nitrate (AN) prills and result in poor blast performance, safety hazards, and environmental problems. To help quantify and resolve these issues, viscosity, mixing, and performance tests were conducted at various temperatures. Diesel fuels No. 1 and No. 2 were studied separately and in blends with 25,50, and 75% RO. Good quality ANFO mixes (94-6) were produced with dry absorbent prills and blended fuel (No. 1 diesel plus RO) at temperatures as low as -40°F (-40°C) with 75% No. 1/25% RO, and at -20°F (-29°C) with 50/50. Diesel fuel No. 2 also made good mixes as low as -30" F (-34°C) with 75% No. 2/25% RO, and at 0°F (-18°C) with 50/50.

Jan 1, 2008

By Carlton E. Brown

In 1935 , Brown and Yant / described a microprojector ( microscopic arrangement for projecting images on a screen ) for use in counting and measuring the size of dust particles in Owens - jet dust - counter and simila dry samples of dust collected from the air . In 1938 Brown and others , described a modification of this microprojector that could be used also in counting dust in impinger samples . Microprojectors of this second type have been set up by many mining companies and others and have been made commercially available . Hamly and Pullen5/ described a modification of this microprojector for use in making rapid comparative estimates on konimeter samples and other determinations . This report contains information on still another modification named the "midget microprojector " because of its small size .

Sep 1, 1944

By G. H. Schnakenberg

In response to the underground mining industry's growing concern with the exposure of workers to the diesel particulate matter (DPM) component of diesel exhaust, a method was developed to estimate the average workplace concentration of DPM that could be expected from using the new lower DPMemitting engines now being approved by the US Mine Safety and Health Administration (MSHA) when these new engines are equipped with state-of-the-art exhaust-control, technology for filtering and combusting DPM. The resulting estimate uses the MSHA-reported particulate index for these engines, the prevailing rule-of-thumb ventilation rate of 150 cfm/hp and the available diesel-exhaust filter technology that has been shown to be at least 80% effective in reducing tailpipe DPM. In the estimate calculation, every engine used in an underground mine is assumed to be equipped with this control technology. Under the stated reasonable conditions, an average DPM level of 90 µg/m3 (mass) is predicted as technically feasible.

By Richard F. Hewlett

An attempt has been made to fit assay data from an underground copper deposit to a three-dimensional polynomial surface as a means of expressing assay points in terms of their mine coordinates by a mathematical equation. The resulting equation was evaluated to predict the grade trend of the deposit. Although the fit obtained by this initial experiment is not considered accurate enough to provide good predictions about the deposit, the methodology is presented in this preliminary report to show the potential usefulness of the technique in mineral deposit evaluation. The technique also should be useful in determining the grade of blocks of ore for production scheduling and blending problems in open pit operations. Further experimentation is needed to increase the reliability of the computer program, to increase the precision of the method, and to make the solution more flexible for use on other mineral deposits.

Jan 1, 1964

By Christopher Mark, Anthony T. Iannacchione

Falls of ground continue to be one of the most serious causes of injury to U.S. miners. Of the 256 fatal injuries that occurred in mining between 1996 and 1998, 59 (23%) were caused by falls of ground (Table 23.1). Falls of ground affect some sectors of the mining industry more severely than others. For instance, nearly 40% of the 98 coal mine fatalities between 1996 and 1998 were caused by falls of ground. Underground miners are at much greater risk than surface miners. Nearly half (45 out of 101) of underground mine fatalities were attributed to roof, rib, and face falls, while only 6% of the 155 surface fatalities were caused by falls of highwalls or slopes. The goal of this chapter is to provide guidance to safety professionals tasked with preventing ground fall injuries. This chapter combines an analysis of the Mine Safety and Health Administration's (MS HA) accident and injury data with a survey of industry "best practices" to safeguard miners from ground falls. Ultimately, this approach can help to form the basis of a sound, proactive ground control program for the mining industry. SOURCES OF DATA All the injury data examined in this study were derived from MSHA's fatal investigation reports and the MSHA accident database. Because falls of ground often result in serious injury, MSHA "Fatalgrams" and fatal investigation reports provide a useful snapshot of ground control issues in the mining industry. These reports are available to the public (on the M FHA Web site at www.msha.gov). Fatalgrams, are one-page summaries that are usually published within a month of an accident. They contain very basic information about the accident with a graphic and a short section on relevant best practices. Fatal investigation reports are the official accident investigation reports filed by MSHA personnel. These reports contain general information about the mine, a, description of the accident, physical factors involved in the accident, a conclusion, and enforcement actions, Enforcement actions typically identify citations and discuss violations to the Federal Mining Law. MSHA also maintains comprehensive statistical data on the mining industry's accident and injury record. The law requires that mines file a report on every reportable accident that occurs, containing information on the accident's location, severity, classification, activity, and nature of injury A short narrative is generally included as well. Accident reports can be searched by many of the above fields.

By T. N. McVay

The Bureau of Mines has developed a field test for detecting the presence of columbium in a variety of minerals containing the clement. The test consists of fusing the mineral or rock powder with potassium pyrosulfate in a porcelain crucible, digesting the melt with hot dilute hydrochloric acid to release the columbium oxide (Cb205), and subsequently reducing the columbium oxide to a lower oxide by adding tin, which gives a blue color to the contents of the crucible. The method will detect 1 percent of contained columbium oxide (Cb205) in a mineral sample provided no tungsten is present. If a mineral containing appreciable titanium is test,-!d in the same manner, the solution in the crucible becomes violet. In the presence of columbium, titanium at first causes a violet coloration of the solution, which after a few minutes is masked by the stronger blue of the reduced columbium oxide. Although tantalum oxide (Ta205) does not interfere with the columbium test, tungsten gives a blue color that is indistinguishable from the color obtained with columbium. A simple method is available to detect the presence of columbium in the absence of tungsten, but when the presence of tungsten is suspected, the sample must be subjected to somewhat more elaborate chemical tests to determine the presence or absence of columbium. Although these latter tests can be made in the field, several steps are involved that arc best performed in the laboratory with simple equipment.

Jan 1, 1962

Develop a training program to help mine workers effectively fight small fires in underground Goal mines. Training would enable miners to make rapid judgments on whether to attempt extinguishment, and how best to use the firefighting equipment on hand. Approach Fire reports were analyzed to define and delineate physical and behavioral variables which affect firefighting activities, and to determine effective procedures for extinguishing small fires. A course was then designed to train miners in such procedures. Finally, the course was reviewed by industry experts and administered to a group of miners to determine needed revisions and to validate the course. How It Works Analysis of fire data showed that six items should be emphasized in teaching proper fire response: 1. Alertness to fire potential. 2. Immediate power cutoff. 3. Internal, external communication. 4. Teamwork in fighting fires. 5. Role of ventilation and position of men inby the fresh air side. 6. Effective use of fire suppressant materials.

Jan 1, 1983

To provide a means for rapidly evaluating proposed mine layouts in order to avoid potential hazards while minimizing loss of coal. The Approach: Development of a computer program that will compute many possible mine layouts by changing the mine plan until the arrangement giving minimal hazards with optimum extraction is found. How It Works: The Hazard Evasion Program for Mine Planning, developed by the Bureau's Denver (Colo.) Mining Research Center, tests hundreds of possible solutions to a mining layout, and by sorting out the 10 best (based on the criteria of maximum safety for workers with minimum abandoned coal), limits the number of choices that need to be considered and appraised for applicability to a given mine scheme. The program is applicable for room and pillar or longwall mining, for oil and gas well hazards, and for other hazards that can be described mathematically such as channel sands, potential bad roof areas, faulting, voids, or water pockets.

Jan 1, 1974

By W. E. Anable

The Bureau of Mines studied the purification of commercially available yttrium by melting it in a 100-kw electron-beam furnace. Button-scale melts were made to determine the ultimate purification that could be attained by melting yttrium at 1,733° to 1,770° C at low pressure (0.05 to 0.1 micron) for 1 to 120 minutes. In addition, numerous melts were made to study the effect of doping yttrium with carbon, 17 selected metallic additions, and 3 compounds. Except for nickel and zirconium, the metallic impurities in yttrium were lowered significantly on extended treatment; silicon was lowered only slightly. The nonmetallic impurities} oxygen, nitrogen, and carbon, were not lowered except on short exposures. In isolated instances, the oxygen content was lowered from 5,860 ppm to about 5,000 ppm. In most instances the carbon con-tent was lowered from 545 to about 220 ppm in 20 minutes and then increased again. It was concluded that yttrium cannot be purified by direct heating or by the doping technique employed.

Jan 1, 1965

By Wilbur I. Duvall

Surface vibrations of ground, rock, and structures resulting from blasting or other sources are often measured with portable seismographs. These instruments are usually supported by a three-point mount or tripod which is simply placed on a horizontal surface on which vibration levels are to be measured. The rigid-body motion of a tripod-supported seismograph is considered from the point of view that there should be no slippage of the feet with respect to the surface and none of the feet should leave the surface as a result of imparted motion. From these studies the following design criteria are deduced which assure that the seismograph will respond accurately to vibration levels as large as 1/2 g.:3/ First, the coefficient of friction between the feet and the surface on which the instrument rests should be as large as possible, preferably approaching unity; second, the center of gravity of the instrument should be vertically above the centroid of the three-point mount; and third, the vertical distance between the center of gravity of the instrument and the centroid of the three points of contact with the surface should be less than the perpendicular distance between the centroid point and anyone of the three sides of the triangle formed by the three points of contact. Portable seismographs that do not satisfy these conditions should be clamped to the surface if vibration levels above 0.1 g. are to be recorded.

Jan 1, 1961

By J. W. Paul, A. C. Fieldner

"In cooperation with the New York and New Jersey State Bridge and Tunnel Commissions, the Bureau of Mines has just completed the construction of an experimental tunnel in the Bureau's experimental mine at Bruceton, Pa., near Pittsburgh, Pa. The purpose of this tunnel is to make a final study of the ventilation problems arising in the adequate ventilation of vehicular tunnels for automobiles and trucks, especially the 9000-foot tubes that are being designed. to handle the traffic between New York City and New Jersey under the Hudson River.Chief engineer, Clifford M. Holland, of the Tunnel Commissions has shown that there are three principal problems involved in planning the ventilation of this tunnel, namely - (1) The amount and composition of exhaust gases from motor vehicles; (2) The dilution necessary to render these exhaust gases harmless; (3) Determination of coefficients of airflow and horse-power required in ducts, bends and openings.Composition of automobile exhaust gases.The answer to the first problem was obtained by making road tests on 101 automobiles and trucks at the Pittsburgh experiment station. These machines were taken from service without any previous adjustment so that the composition and amount of the exhaust gas may be taken as representative of actual operating conditions prevailing in the tunnel. A report covering the results of these tests was submitted to the chief engineer of the Tunnel Commissions, on November 1, 1920, and 411 be published in the report of the commissions. Several papers a have also been published in the technical journals summarizing the important results as regards tunnel ventilation and also with reference to gasoline losses in present-day motor car operation due to the general use of unnecessarily rich mixtures"

Oct 1, 1921

In this U.S. Bureau of Mines report, proposed narrow-vein and longwall mining concepts using drill-split technology (described in part 1 of this series) and in situ liner concepts (described in part 2 of the series) are combined and applied conceptually to environmental problems. Proposed applications deal with (1) acid mine drainage (AMD), (2) solid waste disposal, (3) site remediation, and (4) pollution prevention through innovative industrial design. For control of AMD from abandoned hillside mine workings, it is proposed that source veins be re-mined, processed for residual values, then backfilled using an impermeable compound backfill mix. For solid waste disposal, "vertical landfills" are proposed, consisting of trash-backfilled underground rock quarries. Vertical landfill activities take place in in situ lined containments that geohydrologically isolate the mining-backfilling activities. Site remediation through the creation of in situ underliners, for the capture of toxic leachates, and pollution prevention through the underground storage of toxic, flammable, and explosive materials in in situ containments, are proposed.

Jan 1, 1995

By Rimas Pakalnis, Tom Brady, Lewis Martin

A major focus of ground control research presently being conducted by the Spokane Research Laboratory of the National Institute for Occupational Safety and Health (NIOSH) is to incorporate weak rock masses (such as are associated with operations in the Carlin Trend in Nevada) into existing design relationships. The original database that led to most of the empirical design relationships presently employed in hard-rock mining was derived from fair-to-good-quality rock. In this study, the relationship between weak rock quality and opening design (non-entry/entry methods) is being investigated. The common factor in all mines is a weak back or wall. This work attempts to provide tools that will enable a mine operator to make economic decisions that will also ensure a safe working environment. Tom Brady (for correspondence - E-mail- thb6@cdc.gov)and Lewis Martin are at the Spokane Research Laboratory, National Institute for Occupational Safety and Health, 315 East Montgomery Avenue, Spokane, WA 99207-2291, USA (E-mail• ljm8@cdcgov); Rimas Pakalnis is at the Mining Department, University of British Columbia, Vancouver, British Columbia, Canada (E-mail: rcp@mining.ubcca).

By A. F. Colombo

Infrared spectroscopy employing attenuated total reflectance (ATR) techniques on thin films of dried gelatinized starch solution was used during Bureau of Mines research to determine the structural and impurity differences in starch products and to correlate these characteristics with the flotation response of a nonmagnetic taconite. All of the starch products evaluated gave spectrograms which were characteristic of the anhydroglucose monomer and its polymerization product. Distinct infrared absorption peaks caused by the protein molecule were observed and were used to classify the starches. Correlation of laboratory flotation of calcium-activated gangue from a Mesabi Range nonmagnetic taconite and infrared spectra produced from gelatinized starches showed that protein impurities and linear chain structure limited the effectiveness of starches as iron mineral depressants. Starch products having spectrograms similar to pure amylopectin were generally good depressants for iron oxides, were effective at about one-half the addition that was required for starches that gave infrared responses similar to pure amylose, and yielded acceptable iron concentrates containing 61.5 percent iron and 6.5 percent silica.

Jan 1, 1969

By David M. Hyman

Outbursts are sudden and violent releases of gas and coal that result from a complex function of geology, stress regime, and gas pressure and content. The Bureau of Mines has reviewed methods for prediction and mitigation of such outbursts in use worldwide, as an aid in selecting the proper techniques for use in specific mine environments. Outburst-prone coal may be distinguished from normal coal by its sorption-desorption velocity. Three types of methods used to characterize the kinetics of sorption-desorption are described; all are based on the ability of outburst-prone coal to release, through desorption, methane or carbon dioxide much more rapidly than normal coals. Other prediction methods, based on borehole samples, are also described. Various mitigation methods described and evaluated include (1) working the least stressed, less disturbed, lowest gas content seam in multiple-seam areas; (2) mine opening geometry; (3) inducer shot firing; (4) water infusion; (5) localized stress relief, using boreholes or by cutting a reliever slot in the longwall face; and (6) other gas drainage methods.

Jan 1, 1987

By Maria I. De Rosa

Table 19 and figure 7 show the number of fires and fire injuries for surface coal mines by state during 1990-1999. Table 19 also shows by state the risk rates, employees' working hours, lost workdays, and coal production. For surface coal mines, 215 fires occurred in 21 states during 1990-1999. Ninety-four of those fires caused 93 injuries and I fatality (the yearly average was 21.5 fires and 9.3 fire injuries). Fourteen fires and seven injuries involved contractors. The Ewhr value was 729 x 10° hr (In = 0.026), the CP value was 6,355 x 10° st (Fn = 0.034), and the LWD value was 8,141. Kentucky had the most fires and fire injuries (45 fires and 23 injuries), followed by Pennsylvania (33 fires and 14 injuries), West Virginia (25 fires and 14 injuries), and Indiana (20 fires and 8 injuries). Among these states, Pennsylvania had the highest fire risk rate value (Frr=0.145), while Kentucky had the highest injury risk rate value (In 0.041).

Jan 1, 2004

By Robert P. Vinson

This report describes three coal mine ventilation studies by the Bureau of Mines in which sulfur hexafluoride (SF6) was used as a tracer gas. One of these studies was conducted to determine air movement and leakage in a sealed area. Another was run to determine the ventilation efficiency of a bleeder system. Finally, a study was made of air leakage across permanent stoppings of parallel intake airways. These studies proved sulfur hexafluoride to be a useful addition to the equipment commonly used in coal mine ventilation analysis.

Jan 1, 1976

By R. Raines, S. P. Signer

Researchers from the Spokane Research Laboratory of the National Institute for Occupational Safety and Health installed 39instrumented, fully grouted bolts at six test sites in a trona mine retreat panel to study mine roof stability for the improvement of workplace safety. Variables at each test site included bolt spacing, bolt length, roof span, and location in the panel layout. At most test sites, two rows of instrumented bolts were installed, one in or near the intersection created during development and the other in or near the intersection created during second-pass mining. The most significant factor affecting bolt load was roof span. The highest loads were on the bolts installed in the intersections of the 6-m-wide entry. Mining-induced stress resulting from panel layout was the next most significant factor affecting bolt loading. Minor variations in bolt loading could be attributed to changes in bolt spacing and bolt length. Gas pressure release in the immediate roof contributed to some bolts showing compressional loading during gas bleed-off.

To provide a simple means for rapidly checking methane concentrations at working faces in coal mines while remaining under permanently supported roof. The Approach: A light telescopic probe, through which a gas sample can be pumped Into a methanometer, has been developed. See Figure 1 [ ] How It Works: The telescopic probe consists of sections of small stainless steel tubing encased in sections of lightweight fiberglass tubing. When fully extended the probe is almost 19 ft. long; fully closed it is approximately 5-1/2 feet long. It can be used In either of these positions as well as at intermediate extensions. An approved methanometer is clamped to the probe by a support bracket.

Jan 1, 1975