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By G. W. Jones

As a part of it investigations pertaining to the promotion of safety, the Bureau of Mines is investigating various means, useful for the elimination or mitigation of the explosion hazards of combustible gases encountered in mining and industry. Information has been obtained and a procedure developed whereby the explocibility of many complex, gaseous, combustible atmospheres may be calculated in a simple manner without the necessity of performing laborious laboratory experiments. In a previous publication4/ data were given and a method described whereby the limits of inflammability of gaseous mixtures, including methane, hydrogen, carbon monoxide, nitrogen, carbon dioxide, and oxygen, could be determined by calculation. The information published in that report enables one to calculate the limits of inflammability of such gases as are liberated by mine fires, gases from explosives, automobile exhaust ran, uses present after mine explosions, blast-furnace gas, and other gases containing part of or all of the above-listed constituents.

Jan 1, 1938

By V. B. Dale

This is one of a series of reports covering the mineral resources of the Nation. It describes briefly most of the known tungsten deposits in Yuma, Maricopa, Pinal, and Graham Counties, Ariz. Most of those described were examined by the author. An effort was made to determine the position of the various deposits by section, township, and range and to give accurate road direction to each property from a prominent landmark. All available maps have been used in making these determinations, but in unsurveyed areas it was necessary to make approximate projections of subdivisions. The township and range numbers refer to the Gila and Salt River base and meridian.

Jan 1, 1959

By F. Albayrak

This report is a study of the impact of Federal laws and regulations on the domestic supply of metallic and nonmetallic minerals. The study was confined to pertinent environmental legislation and the recently enacted Federal Mine Safety and Health Act of 1977. Emphasized were the legal requirements placed on individual selected mineral industries, and the economic impact of these requirements. A certain amount of attention was also directed to the particular environmental and health and safety problems generated by selected mineral industries. The study also pinpointed a list of major problem areas having significant impact on the domestic mineral supply.

Jan 1, 1978

By F. Chen, L. J. Gaydos, L. M. Demers, D. C. Kuhn, S. C. Sun

"In this report, we demonstrate that NF-KB, a ubiquitous transcription factor, plays an essential role in silica-induced inflammatory mediator production in the mouse macrophage cell line RAW 264.7. Compared to the effect of lipopolysaccharide (LPS), silica mediated a stronger activation of NF-KB p50/p50 homodimer at early phase of poststimulation. Furthermore, activation of NF-xB by silica and LPS appears to be mediated by different signal transduction pathways. Both silica and LPS increased mRNA expression in these cells for cyclooxygenase II, inducible nitric oxide synthase, tumor necrosis factor-a and interleukin- I a. This expression was attenuated along with the inhibition of NF-KB activation. It is well documented that exposure of alveolar macrophages to silica can initiate excessive production of inflammatory mediators and cytokines from several early response genes (1-3). At the DNA level, a common structural characteristic of these genes is the presence of one to five NF-lCB binding sequences (KB) in the 5'-flanking region (4-6). In resting cells, NF-KB is retained in the cytoplasm in an inactive form by binding to inhibitory protein known as hcBcx, hcB~. p 105 (precursor of p50) and p 100 (precursor of p52) (7-9). Upon cellular stimulation, these inhibitory proteins are proteolytically degraded or processed by certain proteases, which allows the liberated NF-KB to translocate into the nucleus as an activated form to initiate or regulate early response gene transcription by binding to its consensus element (GGGRNNYYCC)(7).In this report, we demonstrate that silica can efficiently induce NF-lCB activation in RAW 264.7 cells, and that silica displays different characteristic from LPS in the activation of NF-KB, both with respect to NF-KB subtype composition and the signal transduction pathway that leads to the activation of NF-KB. In addition, abrogation of NF-KB activation by inhibiting the protease can dramatically reduce the mRNA expression of cyclooxygenase II, inducible nitric oxide synthase, tumor necrosis factor-ex (TNF-o.) and interleukin-lex (IL-lex). These findings strongly suggest that NF-KB plays an essential role in silica-induced inflammatory mediator production in the monocyte/ macrophage cells."

Dec 1, 1996

By L. D. Wyant

That natural gas-gasoline can be used to advantage as a refrigerant is suggested by the fact that the "make" tanks and other parts of the equipment of gasoline plants frequently become coated with frost. The experiments reported in this paper confirm this assumption and indicate that volatile gasoline can be use used to advantage in many refrigerating plants. The Bureau of Mines is making a study of wax distillates in order to find out why satisfactory lubricating oils and waxes can be made easily from certain crude oils and only with difficulty from others. In the commercial distillation of crude petroleum it is customary to separate the distillates into the following groups: (A) Gasolines and naphthas, (B) Kerosenes, (C) Gas oil, and (D) Wax distillate (consisting mostly of light lubricating oil together with small amounts of paraffin Wax).

Jan 1, 1923

By E. J. (Kirk) Conway

Thirty-five years ago underground coal mining equipment consisted of simple but rugged machines powered by electric motors and hydraulics. The machines were maintained by maintenance personnel armed with a basic knowledge of hydraulics, electricity, and mechanical design. Over the years the the machine has been transformed into powerful complex mining systems. The maintenance burden has also increased. During this period significant advances have been made in maintainability engineering and system design techniques. Many of these innovations and techniques are applicable to the design of underground mining equipment. The objectives of this project were to; (1) determine the extent to which maintainability design concepts and principles have been applied to the design of underground coal mining equipment, (2) try to assess the impact of equipment design for maintenance on productivity and safety, and (3) develop a maintainability design guideline to enhance the design of new or rebuilt equipment. An equipment design review was completed at ten operational coal mines. Interviews were also conducted with mine management, safety, and maintenance personnel to identify machine specific design advantages and problems. Visits were also made to six original equipment manufacturers to discuss the design of their equipment for maintenance. Volume I presents an overview of the protocol used and a summary of the findings. Volume II includes the maintainability design guide for underground mobile mining equipment.

Jan 1, 1989

By H. A. Schrecengost

Information presented herein was gathered by examination of 29 fluidized- bed thermal coal dryers and by conferences with manufacturers and users of such equipment to determine what safety features could be incorporated in design, installation, and operation to minimize fire and explosion hazards. Fire and explosion hazards are inherent in certain types of coal dryers in that high temperatures are employed; the sizes and volatility of material handled are capable of propagating explosions; and drying gases are seldom, if ever, low enough in oxygen content to prevent ignitions of dust clouds, distilled gases, or their combinations. This is especially true for fluidized- bed dryers in which the coal is dried in air suspension and in which atmospheric air is constantly introduced to temper the heated furnace gases. Occurrence of fires on heated bedplates, in dust collectors, and in hot gas inlets was common in nearly all the dryers examined. Forceful explosions which produced external effects had occurred in 11 (39 percent), and internal "puffs" or "bumps" had occurred in at least 24 (79 percent) of the plants examined in the study.

Jan 1, 1965

By Samuel S. M. Chan

The objective of this project was to collect information applicable to the design of ground support systems in deep mines to include in-situ rock deformations, deformation-modulus, stresses, and geology and laboratory physical properties. All data collected was to be integrated and evaluated using a finite-elements computer code. In addition, considerable professional "cross pollenization" was anticipated from the association of University and SMRC personnel. Scope of Investigation Before a ground supporting system can be evaluated, the loading conditions existing in the region of investigation, strength, deformation characteristics, as well as other engineering properties of the rock structure immediately surrounding the openings, together with the pertinent geological information, must be obtained and analyzed. It was for this reason the following items were included in this research project: (1) The selection of a suitable area for the investigation. (2) The mapping of the important geological features of the area of investigation. (3) The measurement of in-situ deformation of rock masses immediately surrounding an underground opening of the area of investigation. (4) The determination of ground stresses. (5) The obtaining of in-situ modulus of deformation of the rock masses. (6) The testing of useful engineering properties of

Jan 1, 1972

By S. M. Shelton, W. A. Calhoun, M. M. Fine, T. L. Johnston

"FOREWORDFerrograde manganese ore or its equivalent is essential to the manufacture of every ton of steel produced; although it is well known that there are large deposits of low-grade are in the United States, the production of substantial amounts of ferrograde material from domestic sources presents a problem that becomes more and more critical as the stockpiled ore depleted through inability to procure adequate supplies from foreign sources. Consequently, a program of laboratory,and pilot-plant investigation designed to solve the problem of obtaining a domestic supply of manganese has been undertaken by the Metallurgical Division, Bureau of Mines.This paper is one of a new series that include reports of results obtained in the various investigations conducted under the manganese program. The scope of the program and the organization that was set up to direct and supervise the were discussed in the foreword of the first paper of this series, Report of Investigations 3606 Manganese Investigations. 1. Concentration of Manganese Ores,from the Drum Mountain District, Utah, by S. R. J. D. Vincent, and C. R. Schack. Other reports will be published as the work progresses."

Mar 1, 1942

By H. A. Schrecengost

Information presented herein was gathered by examination of 29 fluidized-bed thermal coal dryers and by conferences with manufacturers and users of such equipment to determine what safety features could b incorporated in design, installation, and op ration to minimize fire and explosion hazards. Fire and explosion hazards are inherent in certain types of coal dryers in that high temperatures are employed; the sizes and volatility of material handled are capable of propagating explosions; and drying gases are seldom, if ever, low enough in oxygen content to prevent ignitions of dust clouds, distilled gases, or their combinations. This is especially true for fluidized-bed dryers in which the coal is dried in air suspension and in which atmospheric air is constantly introduced to temper the heated furnace gases. Occurrence of fires on hated bedplates, in dust collectors, and in hot gas inlets was common in nearly all the dryers examined. Forceful explosions which produced external effects had occurred in 11 (39 percent), and internal "puffs" or ?bumps? had occurred in at least 24 (79 percent) of the plants examined in the study.

Jan 1, 1965

By Edward L. McHugh

The appraisal of mineral resources of the Challis National Forest, Idaho, by the U.S. Bureau of Mines, was made so that the mineral resources of the forest could be appropriately considered in land use planning. Information from this study is intended to help the U.S. Forest Service to incorporate mineral resource data into forest plans. The study was done in conjunction with the U.S. Geological Survey, which released a companion report on the geology and mineral potential of the Challis National Forest in 1989. Mineral development activity in and under the Challis National Forest has been of great economic significance to Idaho and the United States. Since the 1960's, mines within the forest have produced mineral commodities worth more than $590 million A current (1989) commodity prices. Identified mineral resources have a gross value of about $2 billion at current prices, including 8 strategic or critical minerals. The U.S. Bureau of Mines study identified and described 723 active and inactive mineral properties within the forest. Mineral properties with identified resources were evaluated to determine their economic significance, and an assessment was made of the feasibility of mineral development. Of the 2,516,191 acres in the Challis National Forest, about 390,000 acres were classified as having mining development interest commercially important mineral production, mainly of molybdenum, gold, and silver from the Challis National Forest is likely for the foreseeable future.

Jan 1, 1991

By Lawrence G. Houk

Lithium is the lightest of all metals, but as it deteriorates rapidly in air it has no structural applications. Alloys of lithium that will float upon water can be made with other light metals, but these ultralight alloys are not useful in aircraft production or elsewhere at present. Alone or alloyed with alkaline earth meals, lithium acts as reining agent on molten metals, and as a minor constituent with other metals it imparts characteristic properties to the allay. Lithium compounds have somewhat wider application in commerce than either the metal or the alloys. They are used in the glass, ceramic, chemical, and air-conditioning industries and less extensively in the optical, pharmaceutical, electrical, and textile industries. The United States is the leading producer anti consumer of lithium ores and compounds and apparently has the largest known ore reserves. The value of lithium ores and primary chemical byproducts produced is relatively small, yet the lithium chemical industry yields products worth hundreds of thousands of dollars each year, owing partly to the high degree of purity demanded by the trade for most finished products and to the low combining weight of lithium. Fortunately, the low-grade ores can now be concentrated economically, and this fact, together with our extensive reserves, assures adequate supplies to meet any reasonable increase in demand. Lithium is listed as essential by both the American and British war agencies, and its military importance may be greatly enhanced.

Jan 1, 1942

According to industry representatives, U.S. producers were listing unalloyed 95.5 percent aluminum ingot in October at 53-57.5 cents per pound, but reportedly much is being priced at 53 cents. New York dealers raised their October positions by about 3 cents to 56-56.5 cents, mainly to cover spot supply shortages. London Metal Exchange 3-month forward contracts traded up in October from 52.3 to 57.3 cents per pound and closed at 56.4 cents. ASBESTOS The Jaquays Asbestos Corp. has announced the imminent closure of its mine and mill in Globe, Arizona. This is the last asbestos producer in the State having operated continuously, except during the early thirties, since 1914. Cost of compliance with environmental regulations was given as the reason for closure.

Jan 1, 1978

By J. E. Spurr

"Zinc Industry in BelgiumBy March F. Chase, Consulting Metallurgist, Bureau of MinesBelgium for many years was the principal spelter producing country of the world. Gradually its production was surpassed by that of Germany, and Germany in turn lost first place by the production in the 77ti.tad States. For the ten years previous to 1914, 21.6 per cent of the world's spelter was produced in Belgium. Of this production approximately 40 per cent was exported. A large percentage of the balance was rolled and of the shoots thus produced a considerable quantity was also exported.From an economic standpoint even before the war, the Belgian industry was in a unique, if not praoarious, position. Dependent upon foreign countries for ore and foreign markets for sale of products, smeltor was at a distinct disadvantage when compared with some of those of other localities. These disadvantages were partly offset by cheap coal and labor and by whatever there is of value in experience and what we may term for want of a better expression smelting tradition. However intangible this latter may be, it did have and has today an influence on commercial operations.One must not overlook the effect it will have on the revival of the industry. It may not be the determining factor but the fact that for so many years this industry flourished in Belgium, and played such an important role in the industrial life of the country will decide many operators to attempt to re-establish their operations.In 1913 the Belgian spelter plants produced 204,220 long tons of spelter or approximately 20 per cent of the world's production. During this year 500,000 to of ore were treated. The actual value of all of the products derived from treating sine ore amounted to 225 million frames."

May 1, 1919

By H. C. Brunaugh, James Westfield, R. W. Whittaker

"INTRODUCTION The purpose of this circular is to describe the sealing off of a mine fire and subsequent use of carbon dioxide gas to extinguish it.A fire of electrical origin occurred in the Valier mine of the Valier Coal Co., Valier, Franklin County, I11., on March 29, 1949, at about 1:35 p.m. It was discovered about 3:35 p.m. in 5 south west intake airway inby 1 and 2 west panels. The No. 5 southwest airway had caved, and the fire was in the top coal beneath a large fall of rock. All men, except officials, were ordered from the mine. The mine officials decided to seal the fire, and four temporary seals were erected, which isolated approximately 200 feet of 5 south west entry. The seals were completed on March 30 at 2:45 a.m., but on March 31, at 3;40 a.m,, two of them were blown out by an explosion of gas that was produced by the fire. The two seals were rebuilt, the work being completed on March 31 at 12:00 noon, but they were blown out by another gas explosion at 12:10 a.m. on April 1. It was then decided to extinguish the fire with water if possible.To accomplish this, concrete-block dams were constructed. On April 1, about 4:25 a.m., when the dams were about half completed, water was introduced into the fire area through a 2-inch pipe.On April 4, J. G, Crawford, general manager of the Valier Coal Co., notified James Westfield, chief of the Vincennes (Ind.) Branch, U. S. Bureau of Mines, by telephone of the fire in Valier mine and requested assistance to combat it. Westfield, accompanied by F. J. Smith and H. C. Brumbaugh, Federal coal-mine inspectors, went underground and inspected the seals and dams. Later, during a conference with company officials, it was decided that the concrete-block dams were not strong enough to withstand the hydrostatic pressure that would be produced by flooding the fire area. It was then decided to use carbon dioxide gas to extinguish the fire. Four seals were completed, and 5 tons of carbon dioxide gas was introduced into the fire area, which extinguished the fire."

Apr 1, 1950

By Larry R. Wilson

The development effort described herein was directed toward the design and development of a flexible communication system to provide two-way section communications between any telephone on an MCM-101 telephone FDM exchange and a miner provided with a uhf walkie-talkie transceiver. The system also provides normal communication between miners within a working section through the uhf coupler interface repeater.

Jan 1, 1976

By W. Timothy Adams

The production of natural abrasives varied in quantity and value compared with 1976. Output of tripoli-type materials was approximately the same in both quantity and value. Special silica stone products decreased in quantity and increased in value. Garnet production decreased both in quantity and value. The production of emery increased and the production and value of manufactured abrasive material was approximately the same. Foreign Trade Imports of abrasive materials were 23% more in value than in 1976, and exports plus reexports increased in value 10%. Net imports, the excess of imports over exports and reexports, were $35.3 million. The volume and value of all abrasive materials exported varied.

Jan 1, 1980

By Anil Mahyera

Towards the goal of achieving uniform-high-tensions in roofbolts to provide superior roof support[1-7] for extended periods, Terra Tek installed mechanical-anchor bolts in a mine in eight different ways -- under torque/thrust control with and without hardened washers, belleville washers and tension equalization; in a conventional manner with and without a hardened washer. The various bolt groups were analyzed in terms of their tension uniformity and mean tension levels. Installing the bolts accurately with ? a hardened washer under the bolthead, and ? proper torque/thrust control resulted in the mast uniformly tensioned bolts -- with a coefficient of variation of only 14%, an improvement of 3 times over a conventional installation. Also, these bolts maintained a high tension level -- 80% of the installation tension, compared to 50% achieved conventionally.

Jan 1, 1982

By Griffith. F. E., Glei

"INTRODUCTION For many years protective grounding of electrical equipment has been advocated as a means of safeguarding equipment against damage and of minimizing shock hazards to persons. Several codes are in effect covering in considerable detail the items to be observed in obtaining effective grounding in and about industrial plants. Although the coal-mining industry does not have a comprehensive code of its own covering the grounding of electrical installations, a number of States and individual coal-mining companies have issued codes, standards, or rules that include certain requirements with reference to grounding. As early as 1916, 4/ and again more recently, 5/ the Bureau of Mines recommended grounding, particularly as a means of preventing shock to men working on or around electrical equipment.It is common knowledge among electrical engineers of public utility and mining companies that connecting a wire from the frame of a machine to a rod or pipe driven into the earth does not necessarily assure desired protection of surface equipment. In fact, it has often been found necessary to use several interconnected rods and to treat the surrounding earth with salt or other chemicals before the connection to earth would have sufficiently low resistance to give satisfactory results. Even these expedients have not produced the desired results in some localities. It has also been found that ground connections initially having a low resistance may attain high resistance during some seasons of the year. In spite of such difficulties with surface equipment, it has sometimes been assumed that a mining machine resting on the floor in a coal mine is grounded by virtue of its contact with that floor. It has also been assumed by persons endeavoring to comply with grounding requirements that a peg or rod driven into the mine floor would provide a sufficiently low-resistance contact with the earth to be satisfactory as an electrode for connecting the grounding wire from frames of equipment. That both assumptions may be wholly untrustworthy has been proved by the authors in actual tests with underground machinery."

Dec 1, 1943

By William K. Cunningham

The investigation described in this report was begun as part of the Bureau of Mines progress to develop acid processes for the extraction of alumina from low-grade bauxite and. clays. A domestic shortage of high-grade bauxite sui table for treatment by the Bayer process became acute as a result of' World War II; an intensive search for a practical acid process using lower-grade alumina-bearing raw materials was therefore warranted. The laboratory development was described in a preceding Bureau of Mines publication wherein the basic theory for the design and erection of a pilot plant maybe found. A 2-ton-per-day continuous pilot plant was constructed and successfully operated at College Park, Md., which demonstrated conclusively the chemical and mechanical feasibility of a solvent purification process for aluminum sulfate. The estimated production cost of $38.64 indicates that under present market conditions the process would not be economically feasible.

Jan 1, 1948