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By Ricardo Burdisso, Rahul Kadam, Kyle Schwartz, Marty Johnson

Occupational exposure to hand transmitted vibration (HTV) arises from the hand held powered tools extensively used in the mining and construction industry such as rock drills, chipping hammers, chain saws etc. Regular exposure to HTV is the major cause of a range of permanent injuries to human hands and arms which are commonly referred to as hand-arm vibration syndrome (HAVS). In addition to this, the percussive tools generate overall sound power levels in excess of 110dBA in most cases. Such a high sound power level greatly exceeds the maximum permissible exposure limit (PEL) of organizations such as National Institute for Occupational Safety and Health (NIOSH) and the Occupational Safety and Health Administration (OSHA). Long term occupational exposure to this noise has been diagnosed as the main reason for permanent hearing loss in the operators. It is therefore important to develop an understanding of the mechanisms which lead to these high vibration and sound levels and in order to do this a detailed computational model of a pneumatic chipping hammer has been made. This paper presents a nonlinear computational model of a pneumatic chipping hammer. In order to better understand the dynamics of the chipping hammer, the hammer was subdivided into components that are shown in figure 1 (a) (based on a chipping hammer manufactured by Atlas-Copco). The hammer mainly consisted of a center body, a moving piston and a chisel. Compressed air is used to drive the piston inside of a cylinder and on the downward stroke this piston impacts the chisel to create the hammer effect. The machine has one pneumatic valve and this valve regulates the air supply either to the upper chamber or to the lower chamber. The valve changes according to the relative pressures in the two chambers and the supply pressure. There are also twelve different exhaust ports at two positions along the cylinder labeled upper ports and lower ports. As the piston moves the ports can be closed or open (allowing exhaust). Fundamentally, the computational model was made up of two different sub-models, a fluid model and a structural dynamic model as shown in Figure 3 (a) and (b) respectively. The first sub-model takes into consideration the fluid dynamics of the machine since the hammer is driven by compressed air. Equations for the mass flow rate though bleed orifices (assuming an isentropic process) 1 is used to determine the mass flow into and out of the upper and lower chambers. From this the pressures in the two chambers and consequently the forcing on the piston can be calculated. The second sub-model deals with modeling the structural [ ]

Jan 6, 2006

By Frank L. Wideman

"INTRODUCTION The Cphir Hill Consolidated mine was examined 2/ in January 1944. It was recommended that the mine be explored for the purpose of increasing of lead and zinc ore.The Bureau of Mines began exploratory work at the mine in June 1944 and completed it in June 1945. The work was planned to indicate ore that could be developed and extracted quickly and consisted of core drilling and trenching.ACKNOWLEDGMENTSIn its program of exploration mineral deposits, the Bureau of Mines has as its primary objective the more effective utilization of our mineral resources to the end that they make the greatest possible contribution to national security and economy. Its the policy of the Bureau to publish the facts developed by cash exploratory project as soon as practicable after its conclusion. The Mining Branch, Lowell B. Moon, chief, conducts preliminary examinations, performs the actual exploratory work, and prepares the final report. The Metallurgical Branch, O. C. Ralston, chief, analyzes samples and performs beneficiation tests.The work reported on in this paper was conducted under the supervision of S. R. Zinmerly, removal engineer of the Western Region, and J. A. Marsh, district engineer of the Utah-Wyoming district. Subsequent to May 1945, the project was under the supervision of Paul T. Allman, chief, Salt Lake City Division, Mining Branch. The management and employees of the Ophir Development Co. wore very cooperative. Credit is due to the Bureau employees, all local men, for the excellent amount of work accomplished."

Jun 1, 1947

By Louis C. Brichta

The rapid depletion of known deposits of high-grade ore and the need for development of additional reserves, together with increased interest in open-pit mining of low-grade zinc-lead ores in the Tri-State District, led the Bureau of Mines to examine likely mining sites. Underground operations failed to remove all of the ore in a number of areas, and it appeared possible that some of them might be reworked successfully by low-cost open-pit methods. The South Carthage or Hull tract in Jasper County, Mo., was selected by Bureau engineers as favorable for the development of an open-pit mine.

Jan 1, 1949

By Todd M. Ruff

Researchers at the National Institute for Occupational Safety and Health (NIOSH), Spokane Research Laboratory, are investigating technology and methods to monitor the blind areas around large haulage equipment used in surface mines. On average, six fatalities a year can be attributed to equipment colliding with other vehicles or pedestrian workers, or backing over the edge of a dump point. Several off-the-shelf technologies exist for monitoring areas that an equipment operator cannot see from the cab, including radar, video cameras, and radio signal detection systems. NIOSH researchers have tested many of these systems on large dump trucks both at their test facility and at surface mines. This article discusses the technologies available for this application and their effectiveness in detecting objects near an off-highway dump truck. Also, guidance is presented for mine safety personnel who are planning to evaluate collision warning systems or cameras on their haulage equipment. Available Technology Over the past few years, the number and types of systems available for monitoring the blind areas around heavy equipment have increased. Systems marketed for the automotive and recreational vehicle industries have been around for a while. Small video cameras can be found

By Roy H. Poston

The following paper is one of a series on mining methods and practices being published by the United States Bureau of Mines, and deals with the sinking of the Pim shaft (No. 7) of the St. Louis Smelting and Refining Works of the National Lead Co. in the southeast Missouri lead belt. The shaft was sunk in 1922 and 1923 on a tract several miles south of the company's main plant located at St. Francois, Mo., in St. Francois County. The author is indebted to W. H. Comins, local manager of the company, with whose permission this article has been written, for his helpful criticism; and to E. T. Campbell, geologist, and M. Cross, underground shop foreman; and to W. A. Cole, manager of the E. J. Longyear Development Co., who had general supervision of the work and supplied detailed performance and cost data.

Jan 1, 1932

By B. K. Shibler, K. C. Vincent, W. W. Agey

"INTRODUCTION As a part of the investigation of domestic manganese deposits, examining engineers of the Bureau of Mines collected samples of ore from three from three properties in the general vicinity of Tracy, Calif.The Buckeye mine is 23 miles of Tracy, just inside the northeast boundary of Stanislaus County. The mine is owned by K.O. Winship estate of San Francisco and is leased by Verner Allen, also of San Francisco.The ore is principally manganese carbonate occurring in interbedded layers in white chert, with the original,carbonate mineral altered in place. Four samples, representing four types of ore, were submitted, as follows: A, black oxide; B, pink carbonate; C, gray carbonate.The Wilfred Murphy property (also known as the Murmac claims) is approximately 30 airline miles south of Tracy. The property can be reached by road from either Livermore or Patterson and is on the divide separating Santa Clara and Stanislaua Counties Calif. The ore occurs in lenses along a white-chert formation. A 2-ton sample of ore for testing was taken from a dump accumulated from assessment and development work. The Ladd mine, 13 miles from Tracy in San Joaquin County is owned by Pat J. Connolly of Tracy and is leased by Mack C. Lake of San Francisco. The ore is essentially a chert impregnated with manganese oxides and the association is therefore exceedingly intimate and complex. Samples from each of the three adit levels of the mine were submitted for ore-dressing study.As the samples differed widely in physical character and response to ore-dressing methods of treatment, beneficiation of ores from each property was considered as a separate problem. Hence results of the investigations will be prescribed in separate sections of this report."

Nov 1, 1947

By A. Z. Dimitroff, A. C. Moschetti

An improvised rock- dust disseminator, consisting of a 10-gallon galvanized metal milk can that dispenses rock dust in return air currents by the injection of compressed air has reduced the float dust explosion hazards at the Koehler coal mine, Koehler, N. Mex.

Jun 23, 1964

The Bureau of Mines Minerals Information organization collects worldwide data on virtually every commercially important non fuel 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. 829), to place the collection of mineral statistics on an annual basis. The most recent authority for the Bureau of Mines Minerals Information 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, 1984

By Lloyd Williams

1. The investigation shows that the Pewee, Big Mary, and Windrock are the most important beds in Anderson County. About 73 percent of the known recoverable reserves of coal in the county are in these beds, and from them comes 94 percent of the production. The remaining reserves tabulated in this report are in the Joyner, Jellico, Coal Creek, and Poplar Creek beds, and 6 percent of the county production comes from these beds. No production is being reported at present from the Jellico bed, although it was mined years ago. 2. Known measured and indicated reserves in all beds, bared on a minimum thickness of 1/4 inches and on 1,800 short tons put acre-foot of coal in place, are estimated to be 170 million torts as of January 1, 1953 Of this total, 155 million tons is in beds 2S inches and more thick. Areas in each bed were omitted from the estimate because available data relative to the bed characteristics are too meager to permit making an estimate that conforms with the definitions of measured and indicated coal adopted for this study. Should future drilling or development prove reserves in these areas, such reserves should be added to they total estimated reserves.

Jan 1, 1955

By Liane L. M. Kadnuck

This report summarizes the results of a hydrologic research study conducted by the U.S. Bureau of Mines (USBM) in cooperation with Energy West Mining Co. at the Deer Creek and Cottonwood Mines, near Orangeville, UT. The USBM evaluated hydrologic and overburden failure data to assess the response of local ground water to underground coal mining in single-and multiple-seam conditions. Fourteen springs located over the two mines were investigated in the study along with overburden failure response caused by longwall panel extraction. Spring discharge was compared to climatic variation and time of undermining to quantify response to undermining. Spring discharge had been reduced owing to below-normal precipitation during the period evaluated. The response of springs to mining in the vicinity was influenced in part by the thick overburden present at the study site the presence of hydrophilic clays and mudstones in the overburden stratigraphy, and elevation of the springs above mine level, which buffered the effects of undermining.

Jan 1, 1994

By G. F. Friel

A series of experiments in the U.S. Bureau of Mines Safety Research Coal Mine at the Pittsburgh Research Center evaluated the effects of crosscuts on the travel time of carbon monoxide (CO) along an entry to improve the accuracy of a mine-fire locator program. Three entries, ten single crosscuts, and three double crosscuts were instrumented with CO sensors. One-percent CO in nitrogen was released and monitored as it traveled the entries. In addition to dispersion of CO at the front of the CO wave, CO was entrained from the entry into the crosscuts. It was determined for an entry and single-crosscut configuration that the measured travel time for a concentration change of 5 ppm was 27% greater than the predicted time based upon entry volume only, but 13% less than the predicted time based upon entry and crosscut volumes. For an entry and double-crosscut configuration, the measured travel time for the same concentration change was 25% greater than the predicted time based upon entry volume only, but 10% less than the predicted time based upon entry and crosscut volumes. An effective dispersion coefficient for CO dispersion along one of the entries was estimated to be 1.5 m2/ s.

Jan 1, 2010

By J. F. Barkley

Under the procedure of the American Standards Association, with the American Society for Testing Materials as sponsor, the Sectional Committee on Classification of Coals has arrived at the classification of coals by rank as shown in Table 14/. The standard explains the term "agglomerating" used for classification under physical properties, as follows: Agglomerating Index. - Coals which in the volatile-matter determination produce either an agglomerate button that will support a 500-g weight without pulverizing, or a button showing swelling or cell structure, shall be considered agglomerating from the standpoint of classification.***. Pending the adoption of a method by the American Society for Testing Materials, the coke-button grading test5,/ afforded by the examination of the residue in the platinum crucible incident to the volatile matter determination, shall be used.

Jan 1, 1937

By C. W. Davis

There are four parts to this circular and, respectively, they list firms in the Eastern (pp. 5-8), Southern (pp. 9-10), Central (pp. 11-15) and Western (pp. 16-22) United States and Provinces of Canada. Before listing the laboratories and the work performed there, it is proper to make clear what is done and what is not done by Federal bureaus, States, and Territories, as well as by Canada and Mexico. FEDERAL Bureau of Mines. - The Bureau of Mines does not make assays, analyses, or tests for individuals or firms unless they be incidental to investiga¬tions that are of possible benefit to the entire mineral industry. All significant results obtained in this way are made public through published reports. Any mineral sample sent to this Bureau for simple identification will be subjected to a cursory examination.

Jan 1, 1938

By W. P. Diamond, J. R. Levine

The explosion hazard of methane-air mixtures has become an increasingly serious mine planning problem, and an advance assessment of methane gas potential can therefore be essential for a safe and economic mine development pro- gram. As part of its coal mine health and safety program, the Bureau of Mines has developed a simple, inexpensive test to measure the methane content of coal samples obtained from exploration cores. The gas content of coal per unit weight as determined by the direct method test can be used as a basis for a preliminary estimate of mine ventilation requirements, and to determine if degasification of the coalbed in advance of mining should be considered. Since the Bureau began measuring the gas content of coal samples in 1972, experience has led to equipment and procedural changes, the most significant of which has been the development of a ball mill for crushing the coal sample to release the residual gas at the end of the desorption test period. This revised procedure replaces the crushing box and graphical methods described in earlier Bureau publications. The results of 583 direct method tests are summarized in tabular form. These results include data on the gas content of 125 coalbeds in 15 States.

Jan 1, 1980

By John S. Berber

To improve the economics of low-temperature carbonization of coal, the Bureau of Mines is conducting research on the upgrading of the product tar to marketable chemicals. This report describes experiments on the catalytic hydrodealkylation, followed by catalytic vapor-phase oxidation of the dealkylate to phthalic and maleic anhydrides, of mixed residues from the urea adduction of lignite-neutral oil fraction and on the catalytic thermal dealkylation of high-boiling tar acids. The hydrodealkylation experiments were conducted at pressures from 1,000 to 1,750 psig and at temperatures from 600° to 1,000° F. The oxidation was, in all cases, at atmospheric pressure and 9500 F. Maximum yield of maleic anhydride, based on the liquid feed to the hydrodealky1ation unit, was 12.2 percent at 750° F and 1,500 psig; that of phthalic anhydirde was 6.9 percent at 650° F and 1,500 psig. Maximum yield of combined anhydrides was 18.8 percent at 650° F and 1,500 psig. The non-dealkylated feed material, upon oxidation, yielded 8.9 percent and 3.8 percent maleic anhydride and phthalic anhydride, respectively.

Jan 1, 1967

By Benjamin W. Haynes

Cement kiln dust (CKD) produced in the contiguous United States and Hawaii was characterized as part of the Bureau of Mines' program in minerals environmental technology. The mineralogical and chemical composition was determined for 113 CKD samples from 102 plants that normally send CKD waste to landfill. Characterization included the determination of 28 elements, 7 anion species, carbon dioxide, noncarbonate carbon, and chemically bound water. Mercury was determined in 15 samples. Interelement correlation coefficients were determined for 23 elements, 5 anions, CO2, noncarbonate carbon, and chemically bound water. To assess the hazardous waste potential of CKD, the U.S. Environmental Protection Agency Extraction Procedure (EP) toxicity test was performed on all 113 CKD samples. All but one sample were in compliance with the test; the noncomplying sample slightly exceeded the EP toxicity test criterion for lead.

Jan 1, 1982

By D. L. Nussear, W. E. Wallace, N. N. Clark, M. Gautam, G. Hong-Guang

"Results from a study directed towards identifying and measuring the mutagenicity of diesel exhaust particulate matter involved in mining exposures, especially those which may synergistically affect genotoxic hazard, are presented in this paper. Particulate matter emissions from a diesel engine, representative of the ones found in underground mines, were sampled and assayed to determine the genotoxic potential as a function of engine operating conditions. Diesel exhaust was diluted in a multi-tube mini-dilution tunnel and the particulate matter was collected on 70 mm fluorocarbon coated glass fiber filters as well as on 8"" x 10"" hi-volume filters. A six mode steady state duty cycle was used to relate engine operating conditions to the mutagenicity potential.Protocols developed for using a primary component of pulmonary surfactant as a medium for collecting and applying respirable particulate material to cells for mutagenicity testing offer a true representation of in-vivo delivery of such respired aerosols to pulmonary cells and the genetic material within . The surfactant dispersion technique is discussed in this paper. Methods have been developed to sample and assay the diesel soot and diesel soot/mineral dust complexes which would not compromise the surface and physical properties of the particulate material."

Nov 1, 1995

By C. W. Owings

The Bureau of Mines has conducted a survey to determine potential exposure of mine workers to dust produced in connection with intermittent rock drilling in coal mines. Eighteen mines in 3 states were visited, and 30 different operations were observed, as follows: 10 drilling in draw slate, 8 drilling top rock for brushing or grading, 2 drilling in the coal face, 4 drilling in the bottom, 2 drilling top rock for overcasts, 2 drilling in faults or boulders, 1 drilling for roof bolting, and 1 drilling for trolley hangers. Dust respirators were worn by drilling crews during 16 of the 30 operations. Three hundred thirty-two samples of air-borne dust were collected during the survey. ACKNOWLEDGMENTS The information in this report is based on samples collected and observations made in bituminous-coal mines. Operating officials at these mines have contributed to this study, and their cooperation is gratefully acknowledged. All samples were counted by Thomas B. Kirby, chemist, and Dominick A. Ambrosia, scientific aid, and were analyzed by Gretta S. Baur, physicist, and Patricia M. Gussey, scientific aid, of the Health Branch of the Bureau of Mines.

Jan 1, 1953

By R. H. Nafziger

The Bureau of Mines evaluated 18 domestic titaniferous materials with widely varying compositions, mineralogy, and physical properties in electric-arc furnaces, Techniques were devised to recover both the titanium and iron values contained in these materials so that the reliance of the United States on foreign sources of higher grade ilmenites and rutile might be decreased. Most of the tested titaniferous materials responded well to lower grade or byproduct reductants, such as bituminous coals, charcoal, and coke breeze. Sufficient slag fluidity was realized by maintaining from 8 to 12 wt-pct iron in the slags; no contaminating fluidizers were required. Fluid slags containing up to 79, 70, and 54 wt-pct Ti02 were realized from east coast ilmenites, a rock ilmenite, and a titaniferous magnetite ore, respectively. A carbon-lined furnace shell is recommended for minimum slag contamination. Good results also were obtained during extended submerged-arc furnace tests.

Jan 1, 1980

By Michael J. Friedel

As part of an investigation aimed at mitigating the hazards caused by abandoned mine openings, the Bureau of Mines conducted a series of electromagnetic surveys in the Galena, KS, area of the Tri-State mining district. The application of monostatic ground-penetrating radar (OPR) and inductive electromagnetic methods for detecting and delineating hazardous mine openings and attendant features was demonstrated to be feasible for shallow mine workings (i.e., less than 35 ft) occurring below flat-lying areas. Accurate determinations of depth to a mine roof appeared to be limited to roughly 20 ft using the GPR method. Features such as mine voids, fractures, and zones of subsidence were located beneath the Mainstreet (State Highway 26) site using the GPR system. Both the GPR and inductive electromagnetic techniques satisfactorily located mine openings and pillars at the Hell's Half Acre site. Geophysical interpretations were supported by exploratory drilling and mine maps.

Jan 1, 1990