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By R. L. Grant

An investigation was undertaken by the Bureau of Mines to determine the relationship between freespace and ignition probability for borehole shots. A series of experiments was concluded which covered six freespace conditions for a pemissible explosive in a 3/4-inch borehole and encompassed some 700 shots. The results were analyzed statistically. From the analysis of variance, it was concluded that the freespace means were different and that this conclusion is not impaired by possible differences in the explosives used. Within the limitation of this experiment, a definite relationship was found between the freespace and the ignition probability. Specifically, the incendivity increases with increased freespace up to a maximum; beyond this maximum there is some indication of decreasing incendivity. Further investigations are in progress to establish whether the effects of freespace on ignition probability reported here are applicable to the large test gallery, INTRODUCTION A borehole loaded with an explosive charge is a common feature of the routine gallery tests for determining the permissibility of coal-mine explosives, of Experimental Coal-Mine shots, and of the small steel cannon shots used in connection with certain research programs on the ignition of firedamp (6, 10).6/ The question of the interrelationship of freespace, weight of charge, and ignition probability of the methane-air atmosphere has been raised

Jan 1, 1959

By G. W. Jones

From evidence made available during the investigation, it was concluded that the first of a series of explosions occurred at 1:15 to 1:20 p.m. September 21, 1951, in an underground vault that housed pressure regulators on the gas-distribution lines that served Brighten. This explosion damaged the pressure regulators and permitted high-pressure gas to enter the distributing mains and individual-service lines. As a part of the gas-distribution system was not provided with means for protection against such excessive pressures, gas gained access to the interiors of many residences in this area and caused a series of disastrous explosions and fires, which took place during a period of approximately 2 hours after the initial explosion in the pressure-regulator vault. Two persons were killed in the first explosion in a residence, and a third person died of a heart attack attributed to the excitement that prevailed during the explosions and fires, Twenty-three persons were listed as injured. Forty-one residences were either destroyed or damaged - 11 by explosion and the remainder by fires, which developed as a result of gas leakage into residences. Fifteen residences were listed as "completely down" or "gutted." Unofficial estimates of property damage ranged from $1,000,000 to $1,500,000. In view of observations made and information obtained during the investigation, recommendations are presented in this report relative to the natural-gas distribution system in Brighton, which may be helpful in the prevention of similar accidents in this and other communities.

Jan 1, 1952

By L. Allan White

Instrumental analysis is an indispensable tool to many phases of research on rare-earth metals and their compounds; therefore, the development of new and improved instrumental techniques is essential. This report describes an emission spectrometric analytical method using direct-current carbon-arc excitation of various rare-earth-oxide mixtures. Lanthanum oxide serves the dual purpose of an internal standard and a constant major constituent. The versatility of the method was demonstrated by three different applications: (a) Analysis of complex rare-earth concentrates; (b) determination of impurities in high-purity rare-earth oxides; and (c) detection of rare-earth elements in other types of matrices, such as those resulting from beneficiation of rare-earth ores. The average error of analysis in the concentration range of 0.2 to 10.0 percent was 14.6 percent for a group of complex synthetic mixtures of rare-earth oxides. An average error of analysis in the concentration range of 0.05 to 0.50 percent was 21 percent for a group of high-purity rare-earth oxides.

Jan 1, 1959

By Miles B. Royert

Crude Minnesota taconite was charged in the Bureau of Mines experimental blast furnace so that smelting characteristics of such highly siliceous raw materials could be studied and smelting costs compared with those of a standard Mesabi ore. The Bureau recognized that the highly siliceous nature of the crude ore and its relatively low metallic content would be serious economic deterrents to commercial use of the raw taconite, but compensating factors would be low capital investment in production facilities, large tonnage available on short notice, high recoveries of iron, and low delivered cost. Crude taconite smelted readily in the experimental blast furnace. Coke consumption per ton of metallic product was very high, compared with the average established requirements for smelting normal grades of metalliferous raw materials. Slag rates were also inordinately high. Metal quality was erratic as to silicon, and sulfur contents were objectionably high.

Jan 1, 1961

By John E. Hamak

The identified helium resources of the United States were estimated by the U.S. Bureau of Mines at 617 Bcf, as of December 31, 1992. This includes 285 Bef of demonstrated reserves, 85 Bcf of demonstrated marginal reserves, and 37 Bcf of demonstrated sub-economic resources. The identified resources also include 166 Bcf of helium in inferred reserves and inferred marginal reserves and 44 Bcf in inferred sub-economic resources. The identified helium resources contained on Federal lands are approximately 172 Bcf, including 32 Bcf in underground storage in the Cliffside Gasfield near Amarillo, TX. Undiscovered helium resources in the United States are estimated at a most likely volume of 104 Bef, with a maximum volume of 249 Bcf and a minimum volume of 41 Bef. Also reported are 51 Bcf of helium in nonconventional and low-helium-content natural gases. Extraction of helium in the United States occurs mostly from natural gases produced from the Hugoton gas area in Kansas, Oklahoma, and Texas, and the Riley Ridge area in southwest Wyoming. Helium extracted from natural gas in the United States in 1992 was 3.3 Bcf. Some shortfalls in helium supply may occur in about 5 to 10 years.

Jan 1, 1995

Construction workers may be exposed to hazardous dust containing crystalline silica during site preparation when drilling systems are used. The National Institute for Occupational Safety and Health (NIOSH) found that drill dust could be decreased by using wet or dry dust reduction engineering controls, enclosed cabs, and implementing a dust control program.

Jan 1, 2009

By J. M. Kuchta

The Bureau of Mines used laminar hot air jets of l/8- to 3/4-inch diam-eter to determine the hot gas ignition temperatures of various combustible vapor-air mixtures. The combustibles were n-hexane, n-octane, n-decane, a hydrocarbon jet fuel (JP-6), and an adipate ester aircraft engine oil (MIL-L- 7808). Minimum ignition temperatures occurred at a fuel to air weight ratio of about 0.5 and were not greatly sensitive to variations of fuel concentra¬tion. Moderate variations of jet velocity also had little influence on these ignition temperatures. However, these temperatures decreased with increase in heat source dimensions (jet diameter). The hot gas ignition temperatures of the combustibles were not necessarily much greater than corresponding autoignition and wire ignition temperatures when the size (,F the heat source and the ignition criterion were the same.

Jan 1, 1966

By P. R. Jones

A computer program was written for the design of a shell and tube type heat exchanger on a price optimum basis. The program was designed to meet the following requirements: (1) Triangular pitch; (2) single or multiple pass; (3) heating or cooling; and (4) no change in phase. Price optimum design was obtained for four standard tube sizes and standard pitch. Pressure drop both inside and outside were computed and the nearest standard shells having at least the required area were listed. With this information, the estimator can select the heat exchanger best suited for the need. The program was made adaptable to various fluids and to various tube sizes and spacing by reading in much of the required data such as physical properties of the fluids, tube data, and standard shell data in tabular form.

Jan 1, 1967

By J. H. East

The occurrence of hydrogen sulfide in the gas in solution in the oil produced from the Tensleep sandstone in the Elk Basin oil field in Wyoming constitutes a serious hazard to persons working in, that field. Aware of the general conditions because of petroleum reservoir studies being conducted in that field by its engineers, the Bureau of Mine's willingly agreed to a request of the Petroleum Administration for War to publicize the hazard and the measures for overcoming it. In October 1943 and November 1944, the Bureau of Mines investigated the method's used in handling the oil and in disposing of the hydro¬gen sulfide that occurs with it. This circular reports the results of these observations. HYDROGEN SULFIDE OCCURRENCE IN THE. ELK BASIN OIL FIELD The Elk Basin oil field is in Park County, Wyo., and Carbon County, Mont. It is about 18 miles north of Powell and 12 miles west of Frannie, Wyo. The original Elk Basin oil and gas field was situated in an eroded depression surrounded by an inner rimrock about 200 feet high with a bordering higher plateau about 500 feet above the basin floor.

Jan 1, 1945

By Laurence F. Kelley

This paper is one of a series being prepared by the United States Bureau of Mines on shaft-sinking methods and costs at individual operations in various mining districts of the United States. The methods and costs described herein are those of The Consolidation Coal Co. at one of its operations in the Tug River district, McDowell County, W. Va. ACKNOWLEDGMENT The author is indebted to Frank R. Lyon, vice-president, Thos. G. Fear, general manager of operations, and Chas. Enzian, chief engineer, of The Consolidation Coal Co., for valuable assistance and collaboration in the preparation of this paper. W. A. Cole, manager of the E. J. Longyear Development Co. furnished valuable data on methods and performance averages.

Jan 1, 1932

By John J. McClelland

The U.S. Bureau of Mines formed a team in 1991 to begin developing a long-range research plan for computer-assisted mining that would benefit the metal-nonmetal mining industry. This report details the team's accomplishments, specifically, the development of a model that identifies metal-nonmetal mining research needs that could be addressed by the application of automation technology. The report also provides a summary of automation needs and applications based on visits with mining company representatives. The status and future direction of this work is also presented.

Jan 1, 1994

By H. C. Hamontre

[The Bureau of Mines well-bore caliper was designed to provide an instrument that could be operated through 2-inch tubing, which 'a used particularly in many input wells on water-flooding projects of eastern, Kansas and northeastern Oklahoma. It should find wide application elsewhere under many other conditions where it has not been possible previously to make caliper logs with the larger probes used on other instruments. The caliper has three additional advantages over other instruments of this type: (1) It measures 4 radii (up to 18 inches) 90° apart with an accuracy of ± 1/4 inch; (2) the measuring arms can be opened and closed at will by remote control; and (3) it is run and operated on a single-conductor, armored electric cable (Amergraph, type 1-H-0). The caliper probe is 1-3/4 inches in diameter and approximately 6 feet in length. The electrical control and measuring circuits are encased in a stainless-steel tubular case. Measuring arms, made of 5/16-inch aluminum tubing, are attached near the lower end of the instrument. Distances the arms are extended are indicated t the surface by a meter calibrated to read directly in inches. Depths at which the radii measurements are taken are indicated by a wireline depth indicator on the cable-reeling. The instrument is not affected by pressure or temperature, it can be run open hole or under pressure through a lubricator. This paper describes and illustrates the instrument and outlines the operating procedures. A bibliography at the end of the report gives references to articles and patents on the development and use of other well-bore calipers.]

Jan 1, 1954

By F. J. Bailey

"In the fall of 1919, the U.S. Bureau of Mines began an inquiry as to the possibility of utilizing airplanes in conjunction with its rescue work, for quickly transporting engineers and oxygen rescue-apparatus to mine disasters.It was realised that this proposed use of airplanes has serious limitations, and if it were feasible, that the Bureau would have to rely on the cooperation of the established aviation fields of the U. S. Air Service for furnishing airplane service. Therefore Van. H. Manning, Director of the Bureau of Mines, under date of October 28, 1919, wrote the Director of Air Service outlining the rescue and first aid organization of the Bureau, the location of headquarters of district engineers, the distribution of safety cars and stations, and other essential details, and asking whether the Air Service could cooperate with the Bureau in the event of serious mine disasters. Major-General Charles T. Menoher, Director of Air Service, responded that the Air Service would be glad to cooperate insofar as possible, and designated those Air Service stations nearest the district engineers' headquarters, which might be best able to assist.The Bureau of Mines has ten mine rescue cars and eight mine safety stations distributed throughout the mining regions of the United States. The cars are each equipped with sets of oxygen mine-rescue breathing-apparatus and first-aid supplies. The car personnel consists of a mining engineer, surgeon, foreman, first-aid miner, clerk and cook. A foreman miner is in charge of each station and at five of the eight stations are mine safety trucks. The work of the cars and stations is two-fold; (1) Assisting in rescue and recovery work at mine disasters, and (2) training miners in mine rescue and first-aid methods, and in investigations looking to prevention of mine accidents. The country is divided into nine safety districts, with nine district engineers in charge."

Apr 1, 1920

By William L. Crentz

Floyd County, KY., contains sizable deposits of high volatile bituminous coal. Some of the coals have been blended with higher-rank coals and used in the manufacture of high-quality metallurgical coke. The Upper Elkhorn No. 3, Upper Elkhorn No. 2, and Upper Elkhorn No. 1 beds produce the bulk of the present output in the county and contain the main known reserves of coal. Little information is available concerning the quality and extent of the deposits underlying the Upper Elkhorn No. 1 bed, although small operations in the past have worked a bed that is reported to be; the Lower Elkhorn. Undoubtedly, these lower beds occur in Floyd County, but depth Will preclude their development into a major source of fuel as long as large deposits of more-accessible coal are available. More is known of the occurrence of the beds above the Upper Elkhorn No. 3 owing to sporadic mining ventures in the upper measures. Many of the coal samples from beds above the Upper Elkhown No. 3. were collected in mines that had been abandoned. Almost all of the present production of Floyd County coal is taken from the Upper Elkhorn beds, and it is unlikely that their dominant position as coal producers will be challenged in the near future. Table 1 shows the coal production of the county by beds, during 1950.

Jan 1, 1952

By William Seymour, L. D. Schmidt, J. W. Myers, W. T. Reid

"This investigation was conducted by the Bureau of Mines as part of a program of the Solid Fuels Administration to encourage the utilization of anthracite fines, the objective being to determine the practicability of using anthracite fines in the manufacture of packagedThe experimental loss of packaged fuel covered by this report were made at a commercial plant using the Glenn Smith process and ordinarily making packaged fuel from Pocahontas screenings. These lots included several made from straight antimacite mines and others made from various blends of anthracite fines with four different bituminous coals. In all cases an asphalt binder was used. Determinations of the physical properties and the cobustion characteristics o the various samples of packaged fuel were made by the. Bureau of Mines at the Central Experiment Station.The physical tests indicated that a packaged fuel of sufficient strength for ordinary handling can be made from straight anthracite coal or from a wide variety of blends of anthracite fixes with bitunimous coal, using asphaltic binder. However the combustion tests indicated that packaged fuel made from anthracite alone tended to crumble excessively during burning and that as much as 30 to 50 percent of a caking coal may be required In the mixture to produce a block having satisfactory combustion characteristics.The authors wish to acknowledge the. splendid cooperation of Messrs. H. W. Kelly, J. L. Mooney and C. H. Stoss of Columbus, Ohio, who were chiefly responsible for obtaining the materials and making all the arrangements necessary for the production of the packaged fuel for testing.Thanks are due to the officials of Carnegie Institute of Technology for the use of their Olsen. Testing Machine and to H. M. Cooper and W. A. Selvig of the Bureau of Mines for analyses and tests."

May 1, 1946

By Parry. V. F., W. S. Landers

"INTRODUCTION Approximately 1,250,000 tons of 2-1/2-inch and 1-1/2-inch slack, representing over half of the output from 40 to 50 mines, is produced in the Denver region each year. Part of this slack is made by crushing lump, and some of it is rescreened to make pea and modified pea sizes measuring 1-1/2 inches by 2-1/2 inches and 3/4-inch by 1-1/2 inches, round-hole. Modified pea is popular as domestic stoker fuel. Approximately 900,000 tons of slack 0 by 2-1/2 inches, 0 by 1-1/ 2 inches, and 0 by 3/4-inch in size are consumed by industrial plants, the principal consumers being a large power plant and the beet-sugar industry. The power plant uses annually 250,000 to 275,000 tons of pulverized fuel and can pulverize slack of any size, while the sugar factories consume about the same quantity of coal in stokers. The sugar factories store about 110,000 tons of 2-1/2-inch slack under water from January to October, and burn the remainder of their consumption directly during the campaign season from October to December. For this purpose, sugar-factory power plants can use any size of slack, which is recrushed to pass a 3/4- or 1/2-inch screen before burning on chain-grate stokers. About one-third of the 2-1/ 2- inch slack produced in the field is used in smaller industrial plants that employ stokers.Certain factors affect the utilization of 2-1/2-inch slack in the Denver region. The increasing production of hydroelectric power has reduced the consumption of coal at power plants slightly. If more hydropower is generated, the trend of consumption of slack might be downward, unless industrial activity offsets this greater output. Rapid increase in number of domestic stokers during recent years has necessitated preparation of greater quantities of stoker coal, with the result that more lump is crushed, and preparation facilities are changed. At present about 19 percent of the coal produced is crushed to meet the constant demand for industrial fuel as well as the increasing but variable demand for the small domestic stoker sizes. The quantity crushed has increased 12 percent during the last 6 years. These factors are shifting constantly. The trend toward the use of clean and smaller sizes for domestic stokers gives a slack having a larger proportion of fines. In future, even greater quantities of small stoker coal probably will be prepared, and the resulting greater quantities of small slack will have to be used for industrial purposes."

Aug 1, 1942

By Peter Krause

This report provides an overview of the worldwide photographic industry and of the applications of photography. It also covers important technological and market trends, with special emphasis on those factors which may affect the consumption of silver in the future. The text is divided into the following eight sections: 1. Principal manufacturers of silver-based photographic products 2. Major product sectors 3. Structure of the international market for silver-based photographic products 4. Silver-bearing raw materials for the manufacture of photographic products 5. Processing of photographic products: recovery of silver and recycling 6. Methods for estimating the use of silver in photographic products 7. Basic function of silver in photography and alternate image capture and recording systems 8. Brief history of photography Silver- based photographic materials are made for many applications that require different photochemical and physical response characteristics and a wide variety of formats and sizes. All of these products are laminates consisting of a surface-treated support and bonded gelatin layers. Two basic types predominate - films and papers. Films have transparent or translucent plastic supports (mostly cellulose tri-acetate and polyester), while papers have mostly a paper core coated with polyethylene resin layers on both sides (RC type). The front layer contains white titanium dioxide to provide high reflectivity and the back layer a matting agent. However, a few so-called fiber base papers are still supplied. These have a high quality paper base coated with a baryta layer ; i.e. a gelatin layer containing white barium sulfate. The manufacture of photographic film and paper supports requires special procedures and equipment, because of the severe requirements for chemical purity, optical integrity and uniformity (see Table 1 on page 10 for a list of the principal makers of film and paper supports).

Jan 1, 1992

By Tim F. Dyson

Feasibility of employing automated processing and detection techniques in the mine disaster communications problem is demonstrated. Efficient processing methods are developed. These methods have been demonstrated both in a laboratory and in a field environment. Evalua¬tion of existing computer capacity is given along with recommendations for expansion.

Jan 1, 1981

By M. L. Skow

Large tonnages of the manganese ores found in Aroostook County, Maine, are refractory to conventional mineral-dressing techniques and to the common chemical- extraction procedures. The Maple Mountain-Hovey Mountain ores are typical of this type. Because the most promising method of recovering the manganese from these ores has been a chloridizing roast in which the ground ore is in contact with gaseous hydrogen chloride, preliminary batch tests were made with a fluidized bed. On the basis of these tests, it was concluded that fluidization, with careful control of operating conditions, could be employed for this cloridization and warrants further study. Selective volatilization of the iron at 600° C. was unsuccessful. An operating temperature of approximately 950° C. was necessary for a practicable rate of volatilization of manganese chloride. Hydrogen chloride contents of 10 to 100 percent of the fluidized gas gave essentially equivalent manganese recoveries with an 80- minute retention time, For shorter periods reaction was more complete with the higher hydrogen chloride concentrations. At the 80-minute retention period the lower hydrogen chloride concentrations volatilized somewhat less iron and also improved the physical operation of the process. Fluidization gave results superior to comparable tests on chloridization in a fixed bed.

Jan 1, 1956

By V. A. Marple, K. L. Rubow, Y. Tao

"A personal diesel exhaust aerosol sampler has been designed and evaluated in both laboratory and field settings. The sampler uses size selective sampling for the determination of the respirable mass concentrations of mineral dust and diesel exhaust particulate matter found in underground coal mines. This design is based on the premise that diesel exhaust particulate matter is predominantly less than 0.8 um while mineral dust is greater than 0.8 gm. Operating at a flow rate of 2 L/min, the sampler consists of a 10 mm Dorr-Oliver respirable dust cyclone followed by an 0.8 gm cutpoint impactor and an afterfilter. Field evaluations consisted of sampling at 6 different locations in these underground coal mines. Measured aerosol concentration less than and greater than 0.8 um have been compared with a well characterized cascade impactor.Techniques must be developed for measuring the mass concentration of diesel exhaust particulate matter found in underground coal mines due to the health concerns associated with worker exposure to diesel exhaust particulate matter. Diesel exhaust particles are in the respirable size range and have been regarded as a potential occupational carcinogen by NIOSH (1988). Furthermore, a 1988 MSHA advisory committee directed MSHA to develop a sampling protocol for assessing worker exposure to diesel exhaust particles.The University of Minnesota and the Bureau of Mines, over the past 4 years have measured the size distribution of diesel exhaust particles and mineral dust, both in the laboratory and underground mines (Cantrell, 1987; Cantrell et al., 1987; Cantrell and Rubow. 1988; Marple et al, 1986; Rubow et al., 1988: and Watts et al., 1989). To date, measurements have been made in nine coal mines. Seven mines utilized diesel-powered equipment at the mine face while two used electric-powered equipment. The results of these field tests indicate that mineral dust and diesel exhaust particles can be differentiated on the basis of particle size. The measured particle size distributions have been found to be bimodal with a saddle point at 0.8 um. This has led to the hypothesis that one method for measuring worker exposure to diesel exhaust particles would be to collect size fractionated particle samples separated at 0.8 um with the diesel particles being less than 0.8 um and the mineral dust particles greater than 0.8 um.Aerosol size distribution measurements, using a micro-orifice uniform deposit impactor (MOUDI), have been conducted in the mine intake air portal, intake entry to the working section, haulageway, and section return entry. The MOUDI is a ten stage cascade impactor with particle cutpoints ranging from 0.1 to 15 um aerodynamic diameter (Marple and Rubow. 1984b; Marple et al., 1989). The sampling flow rate is 30 L/min."

Mar 1, 1992