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By W. M. Deaton

The formation of gas hydrates in natural-gas pipe lines depends on temperature and pressure conditions in the lines as well as on the presence of condensed water. The operating pressure in a pipe line may be determined easily and usually is available from the records of operation, but the temperature seldom is known. In cooperation with the American Gas Association, the Bureau of Mines, in its investigation of gas hydrates, conducted a pipe-line-temperature survey and studied underground temperatures at depths at which pipe lines ordinarily are buried and the relationship of these temperatures to prevailing atmospheric conditions. A similar but mere limited study of this type was conducted by engineers of the Bureau of Mines a number of yours ago.4/ A summary of the earlier findings was included in a general report by the Bureau on the flew of natural gas through high-pressure transmission lines.5/ In the present study, data on temperature variations were obtained at several places widely separated geographically. This information should assist pipe-line engineers in designing and operating natural-gas pipe lines.

Jan 1, 1941

By John D. Spencer

Clean energy production from coal, oil, and gas, and the development of these and other energy sources continued to be a major objective of the energy research program of the Bureau of Mines.3 In 1971 increased emphasis was placed on the production of fluid fuels and chemicals from coal. Advances were achieved in the development of the Synthane and Hydrane gasification processes for producing pipeline gas from coal (page 31), and progress was made in research on solid wastes utilization (page 2), and on liquid fuels production from coal (page 37); Coal mine safety, solid waste disposal and utilization, coal preparation and transport, and fundamental research on coal and related products also continued to be the subject of extensive research. Improved methods for extracting petroleum and natural gas without surface and subsurface pollution featured research on these vital fuel and energy sources. This research was highlighted by studies of the fracturing systems of reservoir rocks, including subsurface fracture mapping and new fracturing techniques to achieve optimum production of oil and gas (page 52). Of equal importance were projects on oil recovery by water or gas flooding (page 52), by steam injection (page 57), on the identification of oil spills (page 63), and on means to reduce vehicular exhaust emissions (page 66).

Jan 1, 1972

By Herman W. Hill

This report summarizes research into the root causes of failures in mine power systems which impact safety and reliability. Abnormally low fault currents, due to arcing faults, self-excited systems, and fallen trolley wires are examined and quantified. The reliability of components which are critical for safety is studied, as well as reliability of components which are crucial to the mining pro cess. Failure rates are found through in-situ tests, accelerated life tests, studies of mine maintenance, and fault-tree analysis. Reliability data is used to predict fatalities and lost-time accidents through computer-aided fault-tree analysis. Analytical support tasks reported include the deriving of trailing-cable ampacities under cyclic loading, and the measurement of connected ground beds.

Jan 1, 1981

By Reynold Q. Shotts

A study was made of the coal resources of an area in Jackson County, Ala., forming a part of the Flat Rock, Henegar, and Stevenson quadrangles. The area studied is a portion of the Plateau coalfield on Sand Mountain and is near the Tennessee Valley Authority's Widows Creek steamplant. Since no detailed geological study of this area had been published, some reconnaissance work was done. The coalbeds and adjacent strata such as sandstones, conglomeratic sandstones, and conglomerates were studied. Available drill logs, together with the areal geology, provided sufficient information to permit correlation of the coalbeds and an estimation of coal reserves. For all categories of reserves, computed on a regional basis, a total of 72,920,000 tons of coal more than 14 inches thick is estimated for the areas studied in Stevenson, Flat Rock, and Henegar quadrangles. Of this tonnage, 40,001,000 tons is estimated to have less than 60 feet of overburden. The total measured coal reserves for the above three quadrangles are 16,359,000 tons, with 12,411,000 tons under less than 60 feet of cover.

Jan 1, 1966

By C. Thomas Hillman

The practical concern of economic minability of large, high-grade manganese nodule deposits in the northeast Pacific Ocean is addressed in this Bureau of Mines report. Principal objectives are to (1) estimate tonnage and grade of deposits with significant potential and (2) describe and estimate profitability of operations designed to mine and process deposits with greatest apparent potential. Analysis of data from over 800 ship stations identified three areas for detailed study. Average metal contents of these areas range from 1.30 to 1.45 wt pet nickel, 1.00 to 1.24 wt pct copper, 0.21 to 0.26 wt pct cobalt, and 26.8 to 27.8 wt pct manganese. Estimated recoverable nodule resources are 67.0, 66.9, and 148.8 million dry metric tons (t). A system to mine, transport, and process nodules from the three sites is described and costed. Although hypothetical, the system utilizes hydraulic mining and Cuprion (Kennecott) processing, which have been successfully tested at pilot scale. Nickel, copper, and cobalt are the three primary products, but ferromanganese is a considered option. Estimated capital requirements are approximately $1.5 to $1.7 billion for three-metal production. If ferromanganese were recovered, an additional investment of about $130 million would be required. Operating costs range from $71 to $83 per dry metric ton of nodules without manganese, and from $103 to $123 per dry metric ton with ferromanganese. Discounted cash flow analyses predict low returns, ranging from 2.7 to 5.2 pct with ferromanganese and from 4.1 to 6.0 pct without.

Jan 1, 1983

By Richard A. Dick

This Bureau of Mines report describes the evolution of modern-day blasting agent and slurry products and the state of the art of the usage of these products as it exists today. The steadily increasing consumption of blasting agents and slurries at the expense of cartridged high-explosive usage is related. Although safety is not covered in depth, reference is made to pertinent safety literature available. Product formulations, detonation reactions, and detonation products are discussed. Product terminology is defined and the significant differences between the relatively insensitive modern-day dry blasting agents and slurries and cap-sensitive high explosives are described. Blasting agent and slurry properties are discussed, as well as methods of determining and describing these properties, and specific types of products are also discussed with reference to their ingredients,-properties, and field applications. Increasing consumption of slurries, particularly in small-diameter boreholes, and the development of more cap-sensitive varieties of slurries are forecast although dry blasting agents should continue to dominate the market. The consumption of cartridged high explosives will level off or gradually decrease.

Jan 1, 1972

By K. C. Dean

This report is the first of a series concerned with processes for producing magnesium. These reports will evaluate metallothermic, carbothermic , and electrolytic production methods, and will furnish a cost basis for comparing the processes. Areas deemed most promising for future research will be delineated for each procedure. This report presents briefly the history of the metallothermic process, and describes the operations of the Defense Plant Corp. (DPC) plants that employed the process. A hypothetical plant designed to produce 12,000 tons of magnesium per year, using ferrosilicon as a reductant, is described, and raw materials, energy, and major equipment requirements are estimated. Several process modifications are suggested for future research.

Jan 1, 1965

By Earl T. Hayes

[This work represents a continuation of the efforts of the Metallurgical Division of the Bureau of Mines to ascertain and apply knowledge of mineral physics to process metallurgy.]

Jan 1, 1941

By Maurice J. Peterson

The applications of optical spectrochemical methods of analysis for determining trace impurities in metals are described, and the need for developing analytical procedures capable of accurately determining fractional parts per million of impurity elements in metals is stressed. Factors which determine sensitivity of detection and means to extend sensitivity levels in spectrochemical methods are discussed. Examples from the current literature illustrate the diversity of spectrochemical techniques that have been applied to the analyses of varied sample types, Many of the methods use preconcentration procedures to increase sensitivity limits. A bibliography containing abstracts of recent methods in included. Optical spectrochemical analysis is based upon the measurement of radiant energy emitted by atoms of the elements to be determined when a sample is subjected to a suitable source of excitation. The behavior of the valence electrons during excitation, usually by an arc, spark, or flame, produces radiant energy of specific wavelengths. This is recorded as spectral line images on a photographic film or plate by the spectrograph; for direct-reading instruments, the spectral lines are detected with photomultiplier tubes. The spectral lines result from the excitation of atoms in the sample. Each variety of atom produces its own characteristic set of lines, thus serving to identify the elements in the sample. Increased concentrations of elements in the excited sample results in increased blackening of the spectral line images.

Jan 1, 1961

Three complete connector assemblies and six separate contacts were submitted to a series of tests to establish the connectors permissibility and compliance with U. S. Bureau of Mines research Contract #H 0110423 D.C. portion. Test Procedure TPC-0118 was coordinated, and the test plan approved by the Bureau as fully complying with the intent of the contract for the direct current connectors. The components and connector assemblies have been demonstrated in testing that they meet or exceed all the requirements of the test procedure.

Jan 1, 1974

By Mark L. Chatman

This report presents an economic mineral assessment and Inventory of mines and prospects In the approximately 176,000-acre Patagonia Mountains-Canelo Hills Unit of Coronado National Forest. Deposits or areas most likely to experience future development are characterized in terms of their economics, based on data acquired by the author from a variety of sources, and supplemented by USBM field data collected by other workers in 1990 and 1991. Numerous mine maps, rock-chip sample assays, and detailed descriptions of mine and prospect sites are in this report and appendixes. Heavy but sporadic mining, mainly between the 1850's and 1950's was nearly all confined to the Patagonia Mountains. High-grade sulfide veins, replacements, and skarn deposits accounted for most of the production, which included large quantities of zinc, lead, copper, and silver, and considerable quantities of gold. Small Quantities of molybdenum, manganese, tungsten, and placer gold have been mined. Most of the traditionally mined metalliferous sites will not see future activity due to the low tonnages present and removal of most high-grade rock. Possible future development areas include copper porphyries and breccia pipes; most are too deeply buried for current development. Localities where similar deposits may be concealed are identified.

Jan 1, 1994

By Stanley C. Rhoads

The Bureau of Mines investigated the complete ternary system K2 HfF6¬K2ZrF6-l.25 weight-percent HF at 40° C. In addition, solubility curves have been established at 25°, 30°, 500, 60°, and 70° C. These solubility data implemented a study of hafnium enrichment in feed solutions for liquid-liquid extraction processes.. Selected K2HfF6-K2 ZrF6-1.25 weight-percent HF mixtures were equilibrated in a constant temperature bath. Compositions of the equilibrated solutions and wet residues were established from combined hafnium and zirconium oxide and total fluorine analyses. All solubility curves were essentially parallel on triangular coordinates. At 40° C, the solid phase of the K2HfF6-K2ZrF6-1.25 percent HF system is a series of solid solution hydrates with K2HfF6-H20 and K2ZrF6.3H2O segments existing at the respective extremes. Since this system contains K2HfF6-H20 and K2ZrF6.3H20 segments, it is not ideal for simple separation of high-purity K2HfF6 from K2HfF6-K2ZrF6 mixtures by recrystallization. However, it would be useful for producing hafnium-enriched feed solutions from zircon concentrates for liquid-liquid extraction of hafnium from zirconium.

Jan 1, 1973

By J. R. Thoenen

In the summer of 1937 the authors began a series of time studies of the various processes employed in' the production of crushed stone. These studies, made at quarries situated in the eastern and southeastern parts of the United States, have not been completed, but to make results available to the industry as early as possible, it was decided to publish summaries of the studies made to January 1, 1939, as a series of progress reports. The first of these dealt with power-shovel loading and was issued as Report of Investigations 3461 in September 1939. The second, issued in September 1939 as Report of Investigations 3467, dealt with quarry haulage. The present report discusses analyses of time studies of primary drilling at the same group of quarries. OBJECT Or STUDY Pressure of business problems frequently requires the entire attention of quarry management, and in consequence internal plant economies often are neglected. Also, operating officials absorbed in their local problems are prone to overlook possible economies that would attract attention immediately were they critically examining another plant. The authors felt that technical studies at a number of plants, made by impartial engineers, might disclose opportunities to reduce costs or improve efficiency in internal plant processes.

Jan 1, 1940

Coal has been mined in the central Appalachian coalfields of southern West Virginia, western Virginia, and eastern Kentucky for more than a century. The dwindling reserve base consists in large part of coal that would have been considered unmineable by earlier generations. Nearly every current operation is working on a property where coal has been extracted in the past, from seams either above, below, or both. NIOSH is conducting research aimed at helping mine planners prevent hazardous conditions due to multiple seam interactions. To-date, more than 300 case histories have been collected from underground mines, mainly from central Appalachia. This paper focuses on several of the more challenging situations that have been encountered, including: • Room-and-pillar development 20 ft (6 m) beneath full extraction workings at a depth of 1,000 ft (300m) of cover (Virginia) • Pillar recovery 45 ft above full extraction workings at 900 ft (270 m) of cover (Virginia) • Near-simultaneous room-and-pillar mining with pillar recovery with 40 ft (12 m) of interburden and 1,500-2,000 ft (450-600 m) of cover (Kentucky) • Longwall mining directly beneath main entries in overlying seams (West Virginia) • Some of these operations have been highly successful in overcoming the challenges, others less so. The lessons learned from their experience will help ensure that these and similar difficult reserves can be mined safely.

By George W. Huseman, W. D. Mcmillan

"INTRODUCTION Feldspars represent one of the most abundant groups of minerals and constitute nearly Go percent of the material contained in the igneous rocks. They are grouped in a series of related aluminum silicates with varying amounts of potash, soda, and lime. .Approximately 85 percent of the feldspar produced in the United States is used as a flux in the production of glass, pottery, enamel and sanitary ware, brick, and tile. Notwithstanding the abundance of feldspar in the earth's crust, the only deposits that are worked to any extent are the pegmatites or coarsely crystalline dikes where natural segregation of the constituents facilitates recovery of the feldspar with a minimum of free quartz, mica, tourmaline, garnet, and other iron-bearing minerals that are detrimental in most ceramic industries.Although there are three glassplants and numerous other ceramic industries in Texas, all of the feldspar used in these plants is from other States. In the Llano region of central Texas, however, there are numerous coarse pegmatite dikes consisting primarily of feldspar and quartz in ratios up to 3 to 1. One of the more important of these dikes is the Badu Hill deposit in Llano County, Tex., which was first described by Carl Chelf 4/ in 1942. Following an examination of the deposit by W. D. McMillan, engineer in charge of the Texas field office of the Bureau of Mines, in January 1946, a proposal was made to investigate the deposit by core drilling in cooperation with the Department of Ceramic Engineering, University of Texas. This report presents the results of the cooperative investigation, which was begun April 24, 1946, and completed May 17, 1946."

Jul 1, 1947

By S. H. Lorain

Mechanized dirt-moving equipment has greatly increased the scope of prospect trenching by lowering the costs and increasing the speed of such work. Where the soil covering was more than 3 or 4 feet deep, operators were quickly discouraged and abandoned surface exploration in favor of shaft sinking, drifting, or diamond drilling; wildcat trenching was seldom undertaken, even where the soil covering was thin. Although power shovels, trench diggers, and draglines are useful under special conditions, caterpillar-mounted angledozers will usually do the same type of work and have a far wider range of adaptability. They are therefore incomparably the most generally useful equipment for the purpose. Since 199 the Bureau of Mines has been engaged in a widespread search for minerals useful to the war program; this work required a great deal of pioneer exploration in areas where known outcrops were marginal or subcommercial by pre-war standards. Engineers in charge of field operations were quick to perceive the applicability of mechanized trenching on a fairly large scale, particularly in the Northwestern States, where completely exposed vein-outcrops are rare. Probably no other organization to date has done a comparable amount of angledozer prospect trenching under such a wide range of conditions. The following comments and accompanying cost tables are based on work performed chiefly in Idaho, under a variety of physical and climatic conditions. The most important applications of the angledozer for such work may be described under three heads:

Jan 1, 1944

By K. E. Tame

Pollution from radioactive nuclides, principally Ra226, in liquid waste from uranium mills can be minimized by reusing the waste solution within the mill. Such reuse of waste solution in the Vitro Chemical Co.-type process was investigated in the laboratory. Vitro employs an acid leaching process for dissolution of the uranium, countercurrent decantation for liquid-solid separation and washing, and amine solvent extraction for recovery of the uranium from solution. The simulated reuse of barren raffinate in the mill circuit was carried through two separate laboratory campaigns of 29 and 31 cycles. Conventional chloride stripping of the amine was employed in the first campaign, whereas nitrate stripping was used in the second campaign. Dissolution of uranium from the are in the acid leaching circuit averaged 96 percent. Washing efficiencies of 98 to 99 percent were attained by using 4 volume tons of combined raffinate and makeup water per ton of ore. Uranium recovery from the pregnant solution using a 5-percent solution of amine LA-1 in kerosine ranged from 99.3 to 99.9 percent.

Jan 1, 1962

By K. K. Kelley

Thermodynamics data for silicates have applications in the fields of extractive metallurgy, ceramics, and geochemistry. To facilitate these applications, up-to-date tables of heats and free energies of formation are needed. It is the purpose of this report to supply such tables for anhydrous silicates. During the last 15 years the heats of formation of a substantial number of anhydrous silicates have been reliably determined at or near room temperature. This resulted from the development (first by the Bureau of Mines and later by the Geophysical Laboratory of the Carnegie Institution of Washington, by the Institute of Geology of the University of Helsinki, Finland, and by the Department of Geology of the University of Chicago) of accurate solution calorimeters, employing hydrofluoric acid as the reaction medium. Specific references to work of these laboratories will be made in the next section of this report. Also, entropy data at 298.150 K. and high-temperature heat-content values are available for many of these silicates, mainly owing to work of the Bureau of Mines. Most of these entropy and heat-content data have been compiled in Bureau of Mines Bulletins (13, 15).3

Jan 1, 1962

By Frank B. Fulkerson

Aluminum production in the Pacific Northwest has a new potential for expansion and increased stability of operation. This new potential results from greater availability of power; lower freight rates on alumina and aluminum; good market prospects for the metal, including western aluminum market expansion following a decline in defense requirements in the 1950's; and possibility of developing bauxite deposits in the Pacific Basin as well as other mineral resources. INTRODUCTION This is a report of a special study by the Bureau of Mines of the primary aluminum industry of the Pacific Northwest. It outlines developments relative to the United States as a whole.

Jan 1, 1962

By George A. Costello

A theoretical analysis is presented for the static and dynamic response of wire rope in deep-shaft mining operations. Expressions for the stresses in the individual wires of complex wire ropes are derived, and specific results for simple strands, 7x7 ropes, 6x 19 Seale ropes both with and without internal-wire-rope cores, and 6x25 filler-wire ropes both with and without internal-wire-rope cores, are presented for the case of ropes subjected to a combination of axial loading and bending over a sheave. Consideration is also given to the dynamic overloading associated with certain mining operations, such as dumping ore into a suspended skip and accelerating a fully loaded skip upward. Experiments to determine the axial stiffness of wire rope are described. Factors affecting the service life of wire rope, such as residual stresses, contact stresses, and fatigue behavior, are discussed. Specific research areas in need of further investigation are identified.

Jan 1, 1983