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By G. St. J. Perrott, G. W. Jones

"In cooperation with The Edison Electric Illuminating Co. of Boston, Mass., a survey was conducted in 1929 and 1930 by the United States Bureau of Mines to determine the general hazards of combustible gases and vapors in manholes and other underground openings owned by this company. The territory served approximates 650 square miles and includes 46 cities and towns. The transmission and distribution systems are on overhead construction and underground wires and cables run in underground conduits and manholes. There are 17,000 manholes on the system, and also an area in Boston proper served by the Edison tube system. These conduits and manholes are laid in various types of streets from the most modern type of cement roadbed to the older type of loose macadam. The conditions as found could be considered as typical of any public utility in the electric-light and power field. The survey extended over a period of about a year beginning in June, 1929, and ending in July, 1930, and during this time 1,765 different manholes were tested and a total of 4,068 tests were made.Previous to starting the actual survey, one of the writers, G. W. Jones, spent considerable time in Boston determining the best methods of practical· test procedure. In this work cooperation was given by John Campbell, superintendent, special service department, who for a number of years has been making a study of explosions in underground street areas and preventive measures in Boston and various cities.After this preliminary investigation the tests were continued by employees of the Edisun Company. Copies of all records of tests were forwarded to the United States Bureau of Mines Pittsburgh Experiment Station so that the writers were in close touch with the progress of the survey, and changes could be made in the test procedure whenever deemed necessary."

May 1, 1931

By B. J. Scheiner

The Federal Bureau of Mines investigated an electrolytic oxidation procedure for extracting lead, zinc, copper, and silver from lead-zinc concentrates. Concentrates slurried in brine were pumped through the anode compartment of electrolytic cells equipped with selective ion diaphragms. Hydrochloric and hypochlorous acids generated in the anode compartment converted the metal sulfides in the concentrates to soluble metal chlorides, sulfate ion, and elemental sulfur. Metal extractions of 92 to 100 pct were obtained from lead-zinc concentrates at an energy consumption ranging from 1.5 to 5.0 kW-hr/lb metal extracted. Sodium hydroxide was formed in the cathode compartment at a current efficiency of >99 pet. Silver and copper were extracted from refractory tetrahedrite minerals, but the process entailed a relatively high energy consumption. Sealing the top of the diaphragm cell utilized the chlorine more effectively, thereby reducing energy consumption 10 to 50 pct.

Jan 1, 1975

By O. C. Blade

This report on the properties of motor fuels sold through service stations in the United States was made in accordance with a cooperative agreement between the American Petroleum Institute and the Bureau of Mines of the United States Department of the Interior. By agreement with the American Petroleum Institute, identification of the Items is confidential. It present's analytical data for 4,608 samples, representing the products of 101 companies. The samples were collected during December 1956, January and February 1957. As in previous surveys, the gasolines covered by this survey include those from both large and small suppliers. The data were obtained by laboratories of various refiners, motor manufacturers, and chemical companies and submitted to the Bureau of Mines for compilation. A list of the Notional Motor Gasoline Survey reports published during the post 10 years is given on page 5.

Jan 1, 1957

By L. W. Kelly

The primary purpose of this paper is to show the appreciable savings that were made by roof-bolting the main west entry of the Kings mine, which was to be the permanent, main haulage road, as compared to the cost of supporting the same roof with peg timbering as first planned. Additional items that might prove valuable to other mine operators are contained in this paper and detailed below. 1. A detailed cost of the system of roof support known locally as the peg-timbering method is given. It consists fundamentally of supporting steel cross bars on pegs inserted into holes drilled in the ribs close to the roof. 2. A method of supporting the roof in caved entries is shown, where such support must endure for an extended period in haulageways and air courses.

Jan 1, 1952

By P. L. Swanson

Over a recent 20-month observation period, the U.S. Bureau of Mines obtained seismogram records from a single vertical-component, short-period seismometer installed at the surface of a metal mine in northern Idaho. The seismic events were analyzed for local (Richter) magnitude (M), time of occurrence, location, and relation to rock bursting and production blasting. Approximately 150 seismic events with -0.5 = M = 2.9 were located within the mine, yielding a b value (slope of the logarithm of the number of events with magnitude greater than M versus M) of 0.5. Event locations were constrained using a dense underground array of high-frequency accelerometers. Twenty of the surface-recorded events, with 0.5 = M = 2.9, were associated with rock bursts that produced damage requiring at least 1/2 day of cleanup and/or repair. Other possibly hazardous rock bursts, with magnitudes as small as -1.1, were numerous but were not associated with significant structural damage. Approximately 60 pct of the seismic events with M > -0.5 and 75 pct of damaging rock bursts occurred within 45 min of blasting. Estimates of characteristic rupture dimensions for rock bursts with -1.1 = M = 2.9, based on a conventional dislocation shear-slip model of failure, range from 3 to 300 m.

Jan 1, 2010

By H. G. Skavlem

This paper is prepared the United States Bureau of Mines and is descriptive of methods, practice, and costs at the McIntyre Porcupine Mines, Ltd., Schumacher, Ontario. The property is located in the Pearl Lake section of the Porcupine mining district. It is reached by a branch line of the Temiskaming & Northern Ontario Railway from Porquois Junction. There is also a good motor road into the district. The Hollinger Consolidated Gold Mines and the Coniaurum Mines, Ltd., are adjacent properties. Power for both the mining and the pulp and paper industries in the district is supplied by an extensive development of the water-power resources. Weather conditions are favorable for mining operations.

Jan 1, 1933

By G. W. Birge, D. E. Wolfson, J. H. Lynch

This report by the Federal Bureau of Mines describes the carbonizing properties of coals from the principal beds in Boone County , W. Va . Results are given for samples of coals from No. 5 Block , Stockton - Lewiston , Coalburg , Winifrede , Chilton , Hernshaw , Cedar Grove , Alma , and No. 2 Gas beds . Boone County coals rank as high -volatile A bituminous . Eighteen of the 21 samples tested contained from 3.3 to 7.9 percent ash and 16 of the samples contained from 0.6 to 0.9 percent sulfur . Two samples from the Alma and No. 2 Gas beds , the lowest stratigraphically of the seams tested in Boone County , contained from 1.4 to 2.7 percent sulfur . Most Boone County coals yield

Jul 1, 1960

By Mark Sheppard

This paper is the second of a series recording the results of tests made at various quarries throughout the United States to determine, (1) the relation between the size gradation of feed to, and product from, primary crushers; (2) the particle shape of crushed product; (3) the differences in gradation and particle shape produced by different tries of primary crushers; and ( 4) the differences in gradation and particle shape caused by crushing different kinds of stone. Primary crushing has received comparatively little attention in the technical literature in spite of tine fact that the design of the whole crushing plant should be correlated to the performance of the primary crusher.

Jan 1, 1938

By Michael R. Yenchek

Contacts with energized conductors are a major cause of electrocutions in underground coal mines. Sensitive ground fault interrupters (GFI's) installed on in-mine three-phase ac utilization circuits would probably prevent the majority of these deaths. A sensitive GFI is a protective device that detects and interrupts small deadly ground currents in the milliampere range before those currents can cause ventricular fibrillation in humans. Commercially available three-phase sensitive GFI's have not been specifically designed for application in coal mines. The Bureau of Mines therefore tested three commercial GFI models to determine their worthiness for mine power systems. GFI design and construction, transient immunity, reliability, and time-current characteristics were evaluated in laboratory tests. No commercial device was found suitable for mine use without design modifications. The tests results will serve as a basis for the development of a mineworthy sensitive GFI in ongoing Bureau research.

Jan 1, 1985

By W. L. O'Brien, E. A. Rowe

Electrorefined vanadium with additions of up to 5 percent by weight of yttrium, cerium , lanthanum , praseodymium, neodymium, and samarium was melted to ingots in a nonconsumable electrode arc in a helium atmosphere . The ingots were rolled into strips and evaluated for the effect of the alloying elements on hardness , tensile strength , ductility , recrystallization temperature , and microstructure . Except for samarium , average additions of alloying elements of 1 to 2 weight - percent resulted in the retention of 0.12 to 1.05 weight - percent in the alloys and reduced the ultimate tensile strength from about 48,000 to approximately 30,600 psi . The corresponding yield stress (0.2 percent offset ) was reduced from about 40,700 to approximately 20 , 200 psi . Diamond pyramid hardness (DPH) was reduced from 117 to an average of 62 kg /mm² . Increased malleability at room temperature resulted with yttrium and all rare - earth- metal additions , except samarium , particularly with more than 0.25 weight - percent additions . Decreasing oxygen contents corresponded with the changes noted in the mechanical properties of the alloys . The recrystallization temperature of electrorefined vanadium was reduced from approximately 950 ° to 800 ° C. Yttrium or a rare- earth metal content , except samarium , in excess of 0.1 weight - percent in vanadium produced a second phase suggestive of an eutectic which indicated a possible maximum solubility of less than 0.1 weight - percent for both room and elevated temperatures .

Jan 1, 1964

By R. J. Kuczynski

The U.S. Bureau of Mines Reno Research Center investigated, developed, and patented a high-temperature cyanide leaching process for recovering platinum-group metals (PGM) from automobile catalysts. A batch pilot plant was constructed at the center and operated to demonstrate this technology to industry. Approximately 1,600 kg of used pellet, monolith, and metal support catalysts containing 1,700 g (54 tr oz) of PGM was processed. Forty-five-kilogram batches of used catalysts were leached with sodium cyanide solution at 160°C for 1 h in a countercurrent processing sequence. This selectively dissolved the PGM. Average extractions from the used pellet catalyst were 96 pet Pt, 95 pct Pd, and 73 pct Rh. Average extractions from the used monolith catalyst were 84 pct Pt, 81 pct Pd, and 66 pet Rh. Heating the pregnant leach solutions to 275°C for 4 h destroyed the PGM-cyanide complexes, causing over 99.7 pct of the PGM to precipitate from solution. The PGM precipitate was predominantly a metallic powder concentrate, typically analyzing greater than 50 pct PGM. Heating destroyed the cyanide to less than 0.2 mg/L free and total cyanide. Both the pellet and monolith residues were evaluated for disposal using the toxicity characteristic leaching procedure developed by the U.S. Environmental Protection Agency.

Jan 1, 2010

By H. H. Schrenk

The safe use of a refrigerant or any substance depends on knowledge of its pertinent properties and conditions of use; therefore some of the properties of refrigerants that are related to life, fire, and explosion hazards are discussed herein. These data serve as a basis for suggested control measures in the use· of refrigerants. The properties of refrigerants may be broadly classified into three main groups: (1) Those important for refrigeration, (2) those significant from the standpoint of confining the refrigerant, and (3) those that become important if the refrigerant escapes from the :machine or container. The first group of properties, such as latent heat of vaporization, specific heat of vapor, specific heat of liquid, etc., is not considered to be directly related to safety and is not discussed here. The second group, those properties important in confining the refrigerants, has particular significance because· it relates to "built-in" safety. This group is emphasized because it is believed the soundest procedure in designing equipment is to give due consideration .to both the health and safety hazards likely to be associated with the equipment. Furthermore, the toxicity, fire, and explosion hazards are controlled as long as the refrigerant is confined. Some properties of this group are (1) stability, (2) corrosiveness, (3) boiling point, (4) pressure developed in the system, (5) warning odor or irritation, and (6) ease of detection. The third group includes such properties as toxicity (of compound and decomposition products), irritating action, and explosibility.

Feb 1, 1942

By L. C. Marchant

Results of detailed analyses of four cores from the Threemile Canyon area in the P. R. Spring tar sand deposit in Utah are reported by the Bureau of Mines. The cores were obtained by the Utah Geological and Mineralogical Sur-vey as part of a l7-corehole evaluation program in the P. R. Spring, Hill Creek, and Rim Rock tar sand deposits. Average properties of the oil zone in the Threemile Canyon area as deter-mined from these cores are as follows: Oil saturation, 67.4 pet of pore volume; porosity, 29.2 pct; permeability before oil extraction, 133 millidarcies; and permeability after oil extraction, 2,855 millidarcies. Average net thickness of the oil zone is 23.8 ft and average depth to the top of the oil zone is 189 ft.

Jan 1, 1974

By R. D. Leitch

Beside many other damaging effects of acid mine drainage, corrosion of pipe lines and pumps frequently adds much to mine operating costs. Not only is it often necessary to install special and relatively costly acid-resistant materials, but even these may require frequent replacements. It is not unusual for ordinary steel pipe to last only a few days in some highly acid waters, while other common materials, though more resistant, frequently last only a few weeks. In the spring of 1935, local PWA authorities offered to assign a number of persons to various problems under the direction of regular employees of the Bureau of Mines. It was believed that at least some simple tests on as many different kinds of acid-resistant pipes as could readily be obtained might produce interesting and valuable information for the mining industry. This paper describes the tests and some results that have since been noted.

Jan 1, 1938

By R. Havens

During investigations of the occurrence of manganese in the western United States in the early 1940?s, examining engineers of the Bureau of Mines collected samples from seven claims and mines in southern Arizona. For convenience in reporting the results, the work on the properties is grouped in three districts. As the ores were too low grade to be acceptable to producers of ferromanganese, beneficiation studies were made to determine the amenability of the ores to concentration. The San Fernando group is about 10.5 miles south of Patagonia in the Harshaw mining district. G. T. Humphries and D. Alonso held an option on the property, which was owned by H. Bender. Two samples were taken; 1 was a picked sample and the other a representative sample of ore as exposed in the mine.

Jan 1, 1954

By N. S. Dalal, B. Jafari, F. Y. H. Green, V. Vallyathan

"Using electron spin resonance (ESR) spectroscopy we have carried out a systematic study of the measurement of concentrations of organic free radicals in freeze-dried lung tissue. Sixty-six tissue samples were obtained from the National Coal Workers' Autopsy Study (NCWAS). The samples were characterized in terms of the concentration per gram of the free radicals, and examined in relationship to the histopathological parameters such as age, numbers of years in the mining atmosphere, the degree of disease, and smoking history. Preliminary results indicate a positive correlation between the free radicals in the lung tissue and the severity of pneumoconiosis.IntroductionThis paper summarizes our electron spin resonance (ESR) measurements of the concentration of organic free radicals in the freeze-dried lung tissue of autopsied coal miners. This work was undertaken because it is well known that most coals contain carbon-centered organic free radi¬cals,(1,2) and recent studies from our laboratories indicated that reactive free radicals might play a role in the biochemi¬cal mechanism of coal workers' pneumoconiosis (CWP) (3) Thus we obtained 144 lung-tissue samples from the Nation¬al Institute for Occupational Safety and Health (NIOSH) in Morgantown. The samples came from the data bank of the National Coal Workers' Autopsy Study (NCWAS). This selection was unique because fairly detailed histopathologi¬cal information was available for each sample.Other recent studies in this field are those of Ohta et al (4) who conducted ESR measurements on black dust deposited in autopsied human lungs, but no coal miner was included therein. Earlier Retcofsky (2) had examined one lung-tissue sample via ESR spectroscopy and had concluded that the free radicals in the lung tissue reflected simply the fusain (narrow component) ESR signals. The present study was thus undertaken to complement the earlier work (2-4) and the results indicate a positive correlation with the disease severity fairly strongly."

Mar 1, 1989

By O. C. Blade

A comparison of certain properties of the commercial aviation gasolines produced in the United States during October 1949, 1950, and 1951 is presented in table 1, the 1951 data being average values from tables 3 through 6 of the present report. Trends in the average values of certain characteristics of these fuels may be seen in figures 1 through 4 which also indicate the minimum and maximum values. As may be observed, with the exception of changes in kinematic viscosities, the properties of commercial aviation gasolines have not varied greatly during recent years. A list of aviation-gasoline survey reports published by the Bureau of Mines is given on page 6. A summary of the average values of the properties on jet fuels is shown in table 2.

Jan 1, 1952

By R. H. Schutz

TO ASSIST users in the selection of reliable and satisfactory respiratory protective devices, the Bureau of Mines bas established five schedules of minimum performance requirements for the approval of respirators. The current revisions of these schedules3 include 13D for self-contained breathing apparatus, 141F for gas masks, 19B and the amendments to 19B for supplied- air respirators, 21B for dust, fume, and mist respirators, and 23B for chemical cartridge respirators. Copies of these schedules may be obtained from the Bureau of Mines, Publications Distribution Section, 4800 Forbes Avenue, Pittsburgh, Pa., 15213. Approval tests on respirators are performed only at the request of the manufacturer4 of the respirator and at his expense. If the device meets the approval requirements, a certificate of approval is granted on the complete respirator. This certificate states that as long as the respirator is manufactured as originally approved, or in accordance with any changes covered by an extension of the original approval, the manufacturer may advertise and sell his respirator as being approved by the Bureau of Mines. Many industries and regulatory agencies require that respirators approved by the Bureau of Mines he used where respiratory protection is needed. The Bureau of Mines, however, has no regulatory power over the use of the respirators that it approves. It acts as an impartial testing agency to insure the availability of suitable and safe respirators.

Jan 1, 1966

By J. D. Tolman

In view of present interest in a revival of gold mining enterprises, papers dealing with the development of small gold properties are apropos. The present paper deals with the operation of a small gold property in the exploration and development stage, mining and milling 25 tons of ore daily, and indicates what may he expected in the way of mining costs under northern climatic conditions, by practicing rigid economy, at a property where disproportionate overhead costs are unavoidable bacause of the small rate of production. The output of this prospect is treated in a small amalgamation plant which has been described in a previous circular.. HISTORY Prospecting in the district was begun in 1909, and by 1911 the adjoining mines, Hollinger and McIntyre, were in operation. Actual work was begun on the Rochester claim in July, 1922, and carried on through 1924. The property was closed until 1928 when the present company took it over, together with the other holdings of the Canadel Mining Co. A small mill was started as a pilot plant on March 24, 1929, and is still in operation.

Jan 1, 1931

By Mark Sheppard

This p aver is the second of a series recording the results of tests made at various quarries throughout the United States to determine, (1) the relation between the size gradation of feed to, and product from, primary crushers; (2) the particle shape of crushed product; (3) the differences in gradation and particle shape produced by different types of primary crushers; and (4) the differences in gradation and particle shape caused by crushing different kinds of stone. Primary crushing has received comparatively little attention in the technical literature in spite of the fact that the design of the whole crushing plant should be correlated to the performance of the primary crusher.

Jan 1, 1938