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By Alexander May

This report describes a new method of weighing based upon observing the apparent weight of an object ill two separate pure gases. The method is presented in terms of experimental data which prove its soundness, but does not attempt to show the maximum accuracy possible with this technique. The new method incorporates the underlying principle that the apparent weight of an object is a linear function of the density of the atmosphere in which the object is weighed. The coefficients of this linear function are the true mass and volume of the object. From this functional relationship the true mass and volume of the object may be determined.

Jan 1, 1970

By John Durkin

Electromagnetic narrow-band signals were transmitted through the earth at 27 coal mines located throughout the United States. From those Bureau of Mines tests, apparent earth conductivity values were derived based upon a homogeneous half-space model of the earth. The derived conductivity values were found to be inversely proportional to the transmitted frequency and mine depth. A linear regression model relating the logarithm of the conductivity to the mine depth was formulated, and the results indicate that the mine depth can be an adequate predictor of the apparent earth conductivity above coal mines. Apparent earth conductivity was found to decrease with mine depth.

Jan 1, 1984

By John Durkin

Electromagnetic narrow-band signals were transmitted through the earth at 27 coal mines located throughout the United States. From those Bureau of Mines tests, apparent earth conductivity values were derived based upon a homogeneous half-space model of the earth. The derived conductivity values were found to be inversely proportional to the transmitted frequency and mine depth. A linear regression model relating the logarithm of the conductivity to the mine depth was formulated, and the results indicate that the mine depth can be an adequate predictor of the apparent earth conductivity above coal mines. Apparent earth conductivity was found to decrease with mine depth.

Jan 1, 1984

By Nan C. Jensen, Oliver Bowles

"INTRODUCTION Limestone (which consists essentially of calcium carbonate) and dolomite (calcium magnesium carbonate) occur widely in the United States. Their presence is of vast economic importance, because they are used much more extensively than any other form of rock. In 1945, limestone (which, broadly, includes dolomite) was quarried in every State except Delaware, New Hampshire, North Dakota, and Rhode Island, and also in Hawaii and Puerto Rico. Total production (including that used in cement and lime manufacture) exceeded 151,700,000 tons, or 79 percent of the quantity of all kinds of stone sold or used during that year.Important well-known uses of limestone are as concrete aggregate, road material, railroad ballast, for liming the land, for cement manufacture, as riprap for shore protection, harbor work, and spillways at dams, and as building stone.. None of these uses, however, are considered herein. The purpose of this paper is to discuss the industrial and chemical uses that are less widely known and yet are of tremendous importance in a great variety of processing industries. Important examples are dolomite as a refractory furnace lining and limestone as a fluxing agent in blast furnaces, and as a raw material employed in sugar, paper, glass, and alkali manufacture.PRIOR REPORTIn May 1941, the Bureau issued a report 4/ that described these uses in some detail. As new and important developments have taken place during the ensuing years, a revision and representation of the salient features of these uses seem desirable. Asphalt filler and mineral wool uses included in the earlier report are omitted from this paper because they are identified more closely with the highway and building industries, respectively, than with the industrial applications."

May 1, 1947

By A. V. Hooker, E. J. Coggeshall

"The Bureau of Mines for some time advocated the firing of all blasts in coal mines as single shots, and this method of firing is the general practice in American bituminous-coal mines. All single shots can be fired with permissible single-shot units so designed that they will not ignite mixtures of methane and air.If several shots in a face are fired singly it is necessary to return the face after each shot. In some mines having steeply pitching coal seams, this may be dangerous or even impossible, under these conditions shots are usually fired simultaneously.Several shots cannot be fixed simultaneously with permissible single-shot blasting units, and safe types of multiple shots blasters are not readily available. This means that the firing of multiple shots in gassy mines is usually accompanied by the possibility of gas ignition as the blast occurs.Tests have been made at the Pittsburgh Experiment Station to determine the possibility of developing safe types of multiple-shot units suitable for such use, or of applying other type safely in gassy sections of mines where firing shots singly is impracticable.The tests may be divided into the following four groups:1. Tests to demonstrate hazard in the use of existing types of multiple-shot units of the portable generator type.2. Tests to show the electrical characteristics of multiple-shot generator units relative to the possibility of preventing igniting sparks and of modifying the design and application of such units in furthering safety."

Mar 1, 1935

By M. J. Ferrante

Enthalpy and entropy increments above 298.15° K were determined for cop-per sulfate between 298° and 1,000° K and for copper oxysulfate between 2980 and 1,146° K by the method of copper-block drop calorimetry. Enthalpies, entropies, and heat capacities are tabulated for both compounds. In addition, free-energy functions are tabulated for the sulfate. Equations representing the enthalpies are given for each compound.

Jan 1, 1972

By Richard L. Rains

The Bureau of Mines conducted a mineral investigation of the 29,000-acre Dixie Summit area near Elk City, Idaho, during the summer of 1989. At the Petsite mine a marginally economic, identified resource of 4.9 million tons with an average grade of 0.023 ounces gold per ton was delineated. Possible resources of gold, along with silver, copper, lead, and zinc, occur in at least eight other lode deposits. Placer gold may be recoverable by recreational-sized suction dredges in some stream drainages, Five lode mines in the study area have produced over 5,516 ounces of gold (placer gold production was not recorded), 4,757 troy ounces of sliver, 36,746 pounds of lead, and 3,800 pounds of copper. Current mining claims in or adjacent to the study area total 460 lode and 70 placer claims. There are two patented lode claims within the Dixie Summit study area.

Jan 1, 1991

By W. G. Messner

Pipelines for transporting crude oil and refined products in the United States totaled 189,982 miles on January 1, 1959. This mileage was less than a 1-percent increase from the 1956 total of 188,540 miles. During the three-year period (January 1956 - January 199), 14,886 miles of new pipe and 10,649 miles of secondhand pipe was laid. Pipe taken up in the same period was 24,093 miles. The facts regarding pipeline mileage were obtained by the Bureau of Mines from pipeline companies and information provided by the Interstate Commerce Commission. Crude-oil gathering lines, as of January 1959, were 40 percent of the United States pipeline mileage and totaled 75,182 miles, an increase of 1,656 miles during the three-year period. Crude-oil trunklines totaled 70,317 miles or 37 percent of the United States pipeline mileage, a decline of 8,277 miles from the 1956 total. Some of this loss is attributed to the converting of crude lines to refined products. Refined product lines in January 1959, totaled 44,483 or 23 percent of the United States mileage, an increase of 8,063 miles during the three-year period.

Jan 1, 1959

By W. M. Deaton

The Keyes Helium Plant of the Federal Bureau of Mines was constructed under an expedited schedule, to supply the urgent and growing demand for helium in atomic energy, missiles, aerology, space exploration, shielded-arc welding, and low-temperature research. Construction began in December 1958 and ended in August 1959. The plant, near Keyes, Okla., processes 2 percent helium-bearing natural gas from the Keyes gasfield. In 1960 the plant produced and shipped 263 million cubic feet of helium (equivalent to an annual rate of 290 million cubic feet). Production cost was $9.11 a thousand cubic feet of helium. A low-temperature process involving two steps is used; the first separates a crude-helium product from the natural gas at about -250° F. and 225 pounds per square inch gage (p.s.i.g.); and the second purifies the crude helium to a high-purity product (Grade-A helium, 99.995 percent helium) at about -320° F. and 2,750 p.s.i.g.

Jan 1, 1961

By C. E. Henning

The total number of petroleum refineries in the United States on January 1, 1958, was 318 and their total crude-oil throughput capacity was 9,407,707 barrels per day, according to the Bureau of Mines annual survey. During 1957, 3 new refineries began operating while 4 refineries were retired. Although there was 1 less refinery, the total crude-oil throughput capacity at the beginning of 1958 was 284,033 barrels per day, or 3 percent, more than the January 1, 1957, level. During 1957 all refinery districts showed increases in capacity. The largest increase, 27 percent, occurred in the West Coast district followed by the Indiana-Illinois-Kentucky district with 14-percent increase and the Texas Gulf Coast district with 13-percent increase. The national increase in capacity had the effect of raising the capacity of the average refinery from 28,601 to 29,584 barrels per day. New crude-oil capacity under construction on January 1, 1958, totaled 185,265 barrels, and an additional 297,885 barrels capacity was reported building as replacement for existing facilities. Included in total new construction were 2 new refineries, 1 in Washington and another in Texas, with planned processing capacities of 45,000 barrels and 8,550 barrels per day, respectively.

Jan 1, 1958

By Jack C. White

The purpose of this Bureau of Mines research was to determine the technical feasibility of direct sulfuric acid digestion of Florida land-pebble phosphate matrix. Preliminary tests in a continuous digestion circuit showed that 92 to 96 percent of the P2O5 contained in the matrix was extracted, while the P.05 concentration in the product acid ranged from 21 to 30 percent. The waste filter cake contained about 1 percent P205 and up to 18 percent water. These sandy compact filter cakes, comprised mostly of quartz and gypsum, appeared to be suitable for backfilling and reclamation of mined lands.

Jan 1, 1975

By Phil Patton, Bill M. Stewart, Curtis Clark

Handling materials in underground mines continues to be a major safety problem. To help reduce materials-handling injuries, the National Institute for Occupational Safety and Health (NIOSH) at the Spokane Research Laboratory is developing, modifying, and testing equipment to replace the necessity of doing lifting tasks manually. To reduce single-event lift injuries, equipment having mechanical automatic weight sensing and balancing control was investigated. The Coleman manipulator was selected for testing. Modifications to the Coleman manipulator to make it more suitable for underground mine use included mobilization, self-containment, all-purpose gripper attachment, and support jacks. To reduce or eliminate the need to clean off manually the materials that commonly plug grizzly openings (timbers, wire mesh, roof bolts, and other debris), a track-guided pincher arm device was developed. The TGPA attaches to an impact hammer head, and the pincher arms are controlled by the operator of the hammer. Oversized rock can be broken with the pincher arms in the up position; the arms can then be lowered to grab and remove debris. Sweeping action to remove cohesive fines bridging grizzly openings is also greatly improved. This device is especially useful in recessed grizzlies. An industrial gun was tested to evaluate its effectiveness in breaking oversized rock. Boulders up to 76 cm in diameter were successfully broken to minus-33 cm. Although methods to control fly rock need to be developed, an industrial gun may be a safe and inexpensive alternative to breaking oversized rock in certain underground mining situations.

By Marvin E. Lane

This paper , which describes the mining methods and practices at the Hayden Creek lead mine of St. Joseph Lead Co. in southeast Missouri , is one of a series being prepared by the Bureau of Mines on mining methods , practices , and costs in various mining districts of the United States . The Hayden Creek mine is in the W 1/2 sec . 7 , T. 36 N. , R. 4 E. , St. Francois County , Mo. , about 1 mile southwest of the town of Frankclay ( fig . 1) . The mine is on the west edge of the mining district known as the Lead Belt . However , neither the ore body nor the underground workings are connected with those of any other mine in the district . In contrast with most operations in the district , underground haulage is entirely trackless , and nearly complete delineation of the large , well -defined ore body by drilling permitted comprehensive planning of development and mining in advance of shaft sinking . The ore differs in character and occurrence from that of the main ore deposits in the Lead Belt in that the lead mineral , galena , occurs in the dolomitic matrix enclosing granite boulders instead of in dolomite limestone .

Apr 1, 1957

By Kenneth L. Cashdollar

The Pittsburgh Research Laboratory (PRL) of the National Institute for Occupational Safety and Health (NIOSH) and the Mine Safety and Health Administration (MSHA) conducted joint research on dust explosions by studying post-explosion dust samples. The samples were collected after full-scale explosions at the PRL Lake Lynn Experimental Mine and after laboratory explosions in the PRL 20-L chamber and the Fike 1-m3 chamber. The dusts studied included both high and low volatile bituminous coals. Low temperature ashing for 24 hr at 515°C was used to measure the incombustible content of the dust before and after the explosions. The data showed that the post-explosion incombustible content was always as high as or higher than the initial incombustible content. The MSHA alcohol coking test-was used to determine the amount of coked dust in the post-explosion samples. The results showed that almost all coal dust that was suspended within the explosion flame produced significant amounts of coke. Measurements of floor dust concentrations after LLEM explosions were compared to the initial dust loadings to determine the transport distance of dust during an explosion. All of these data will be useful in future forensic investigations of accidental dust explosions in coal mines or elsewhere. Disclaimer: The findings and conclusions in this report are those of the authors and do not necessarily represent the views of the National Institute for Occupational Safety and Health or the Mine Safety and Health Administration.

Jan 1, 2006

By K. K. Kelley, W. W. Weller

Heat capacity measurements of lead molybdate and lead tungstate were conducted over the temperature range from 51 ° to 298 ° K. The entropies were found to be S298.15 = 39.7 ± 0.5 cal / deg mole for lead molybdate and S298.15 = 40.2 ± 0.5 cal / deg mole for lead tungstate . The entropy values were combined with other pertinent data to obtain the entropies of formation of the two compounds from their constituent elements and oxides .

Jan 1, 1964

By J. A. Eisele, D. J. Bauer, D. E. Shanks

As part of its effort to produce cell - grade alumina from clay , the Bureau of Mines investigated the hydrogen chloride gas - sparging crystallization of aluminum chloride hexahydrate ( ACH ) from aluminum chloride liquor , to provide information for optimizing the crystallization operation . Four parameters important in controlling the crystallization of the aluminum chloride hexahydrate and the concentration of impurities , particularly phosphorus and magnesium , in ACH crystals are ( 1 ) aluminum chloride concentration in the feed solution to crystallization , ( 2 ) hydrogen chloride gas flow rate , ( 3 ) temperature , and ( 4 ) concentration of phosphorus and magnesium also in the feed solution . Parameters 1 , 2 , and 3 affect crystal formation . The combined effects are very important because the phosphorus and magnesium concentrate in the crystals during the early stages of crystal growth . Aluminum chloride hexahydrate of cell -grade purity was crystallized from saturated aluminum chloride solutions containing less than 0.003 wt - pct P205 and 0.010 wt - pct Mg0 . Crystallization temperatures less than 60° C decreased crystal purity .

Jan 1, 1965

By William H. Lesser

Never before have mine managers in the anthracite region of Pennsylvania been so seriously concerned about the rising cost of pumping mine water. Many of them know that future pumping charges may affect their operating profits adversely to an extent that will make it necessary to abandon some mines. Increased pumping charges in the anthracite industry are currently comparable in importance with higher mining costs; in fact, profitable operation of some mines depends not only upon the cost of mining coal but also upon whether they can be kept free from water at reasonable cost. Pumping charges are relatively low during the early development of a mine, but they increase rapidly as development progresses. Numerous crop falls, strippings, and. abandoned adjacent properties contribute unfavorably to the volume of water produced during mining. The foregoing conditions and the existence of large underground pools below existing mining levels present water problems of such magnitude and cost that some mine owners cannot continue to operate profitably.

Jan 1, 1950

A knowledge of the mechanics of wave propagation through the earth is essential if reliable communication systems are to be designed for coal mine environments. To obtain a reliable basis from which accurate propagation predictions could be drawn, a series of theoretical studies have been prepared for the US Bureau of Mines by Mr. Ramsay Decker of Spectra Associates, Inc. through a subcontract with Collins Radio Group. These reports formulate the analytical techniques from which we may derive frequencies and antenna configurations that yield the optimum signal-to-noise ratios over the greatest distances in mine environments. The reports of sections 2 and 4 deal with analytical techniques for determining the signal-to- noise ratio within a mine environment for loop-to-loop and line source-to-loop antenna con- figurations. The analytical results of these reports were then implemented into computer programs to obtain predictions concerning through-the-earth signal propagation. These preliminary predictions are based on noise data compiled by Bensema, Maxwell and Stone, and WVU prior to the extensive research conducted by the National Bureau of Standards (NBS). These initial measurements indicated a 20- to 30-dB lower noise level than that measured recently by NBS. The recent NBS data is that used by Collins in the final predictions. The following outline indicates the order and subject matter treated in the subsequent sections: Section 2 - Signal-to-Noise Analysis for Loop-to-Loop Mine Communications Section 3 - The Horizontal Electric Dipole Section 4 - Signal-to-Noise Analysis for Down-Link Line Source Mine Communications Section 5 - LF Communication Section 6 - The Application of Recent NBS Noise Data to Mine Communications Section 7 - Analysis of Mine Communication Propagation Programs

Nov 15, 1974

By Ralph H. Espach

The value of careful fractionation in the manufacture of petroleum products is recognized more and more by petroleum refiners. Recent studies have shown that the quality of the products depends largely on the type of fractionating equipment and on the care used in operating the equipment. For example Rue3 has shown that careful fractionation of pressure distillate will greatly reduce the amount of chemical treatment necessary to produce finished gasoline. The advantages of the combination of pipe still and bubble tower in obtaining good fractionation are well recognized in the petroleum industry. However, the equipment designed in the past has in general been much too large for convenient laboratory use. The present paper describes a continuous-distillation apparatus for the laboratory study of fractionation. This apparatus has given very satisfactory results in the study of different crude oils and petroleum products. A discussion of the theory and action of bubble towers has not been given, as this subject has been discussed previously by Cooke and Rue4. It is believed that the distillation curves of the products obtained from this apparatus show clearly its capabilities.

Jan 1, 1928

By A. E. Isaacson

Bureau of Mines researchers developed and tested equipment to measure corrosion rates on a commercial scale mill. Bench-scale experiments were designed for duplicating ore grinding conditions closely enough so that realistic rate determinations could be made in laboratory tests. Rates measured in a laboratory system compared favorably with those measured in the field. Cast steel was found to have corrosion rates in a copper mill and laboratory test cell of 22 and 21 mpy, respectively. Corrosion was found to account for less than 5 pct of the total grinding media wear in the operations studied.

Jan 1, 1988