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By M. J. Ferrante

The Bureau of Mines investigated the applicability of the freeze-drying technique for preparing dispersion-strengthened tungsten powders suitable for conversion by powder metallurgy into materials which might have improved high-temperature strength. Extruded rods from compacts of tungsten-5 vol pct thoria had at 1,650° C a tensile strength of 30,300 psi and a 10-hour stress-rupture strength of 12,700 psi, These are slightly below those measured for swaged rods of commercial tungsten-3.7 vol pct thoria. Only those tungsten-thoria dispersions containing a stoichiometric deficiency of oxygen yielded a significant strengthening effect. A low-melting eutectic formed in extruded tungsten dispersions containing either zirconia or yttria, which caused a lowering of the tensile strengths. These tensile strengths were only slightly higher than strengths of elemental tungsten made from commercial powder having a particle size of 2.4 microns (Fisher subsieve). Sheet made from this commercial tungsten had a slightly higher tensile strength than tungsten made by freeze drying, but the freeze-dried tungsten sheet had a lower recrystallization temperature, a lower ductile-to-brittle transition temperature, and a higher purity.

Jan 1, 1971

By Vance G. Leak

A technique for recovering copper and steel from metallic scrap has been developed by the Bureau of Mines based on preferential melting in molten salt baths at 1,150° to 1,250° C, The molten salt, preferably barium chloride or calcium chloride, both minimizes oxidation of the metals and promotes heat transfer. Cleanest separations (0.01 percent copper remaining in iron) have been achieved by pretreatment (dipping or spraying) with sodium sulphate or sodium silicate, which alters and coats the surface of the iron to inhibit the alloying or brazing with copper. An economic evaluation of the process was carried out on six combinations of sweating media and inhibiting reagents. On the basis of the postulated model, a cost of about $0.20 per pound of copper recovered has been determined for the sweating treatment operation.

Jan 1, 1973

By E. P. Ferrero

Crude oils from fields throughout the world are analyzed by the Bureau of Mines to determine the characteristics of the oils and their contribution to the petroleum resources of the world. Analyses are reported for 169 foreign crude oil samples from 122 oilfields in Africa, Asia, Australia, the Caribbean, Europe, North America, and South America. Tables show the geographic and geo- logic origin of the samples, names of companies that supplied the samples, annual production for the fields, general characteristics and analytical and computed data, hydrocarbon-type data, cumulative production of the larger fields, and references to sources of geological and field development information. The analyses were made by the Bureau of Mines routine method and comparisons may be made with more than 8,000 other such analyses.

Jan 1, 1972

By D. R. Flinn

A newly developed chemical conditioning technique, which greatly simplifies the preparation of plating baths for the electrodeposition of titanium diboride (TiB2) coatings, is described in this report. The new plating technique was used to prepare samples of titanium diboride (TiB2) coatings on three types of substrate materials. These samples were then evaluated in both low- and high-speed wear-test programs to determine the wear resistance, microhardness, and adhesion of the coatings. In general, it was found that the wear resistance of the coatings is independent of substrate. Scanning electron micrographs have shown that the coating wear surfaces are very smooth, suggesting slow and continuous removal of the coating during the wear test (that is, adhesive wear). Adhesion between the coating and all substrates was excellent. Microhardness results show that the TiB2 coating is harder than alumina, with a hardness value exceeding 5,000 kg/mm2 measured in one test. The results of the wear tests show that TiB2 coatings have relatively poor wear resistance compared with alumina in low-speed unlubricated sliding environments, but exhibit wear properties comparable with alumina in high-speed unlubricated sliding environments.

Jan 1, 1981

By Bruce I. Thomas

[THIS PAPER, tine of a series on placer ml n in iii Alaska, describes mining methods and gives unit costs at operations where hydraulic and mechanical excavation equipment is used with nonfloating washing plants. The mining methods described were developed during the last 30 years to copy with conditions peculiar to arctic and subarctic regions arid are now used by a large segment of the placer mining industry in Alaska. The operations described have been classified if m ii into three main categories: Those having sluices at a bedrock level, those having sluices above bedrock and those having mobile nonfloating washing plants (dryland dredges). Diesel-powered bulldozers and draglines convey or clevate gold-bearing gravel to the sluices, remove tailings, and strip waste gravel and other overburden. Diesel-powered centrifugal pumps supply water foe sluicing and hydraulic stripping. Detailed descriptions and unit cost arc presented for 14 operations to illustrate the numerous arrangements udder the first 2 categories.]

Jan 1, 1959

By H. H. Schrenk, Carlton E. Brown

"The purpose of this paper are (1) to present a broad picture of the recognized methods of measuring the various forms of atmospheric pollution; (2) to evaluate the significance of such measurements; and (3) to suggest suitable methods for obtaining comparative information on the concentration of contaminants in city air.The atmosphere (the gaseous envelope surrounding the earth) consists of a mixture of gases. These gases and their usual proportions are:4/The volume of water vapor in the atmosphere ranges from almost zero (in very cold weather) to about 5 percent arid averages about 1.2 percent.Strictly speaking, any other substance in the atmosphere or an excess of any of the substances mentioned (with the possible exception of water) is a contaminant. Needless to say, there are many contaminants in the atmosphere.In accordance with their physical state, contaminants may be classified as gaseous or particulate, and the latter may be classified as solid or liquid matter. Particulate matter, especially when dispersed in some medium such as air or some other gas, sometimes is referred to as dispersoid, and the complete system of gas and dispersoid is referred to as aerosol.All substances on the earth are potential sources of atmospheric contaminants. Combustible materials (particularly fuel for heating and power), sea water, earth or soil, metals, and animals (including man) are some of the important sources of contaminants.Ordinarily gases are produced by chemical processes, whereas dispersoids are produced by both chemical and physical processes. There are two general dispersoid-producing processes: (1) Condensation, in which molecules join to form larger units or particles, and (2) disintegration, in which large units are reduced to the particulate range (which for the purpose of this article may be considered to be from 100 microns, or 1/254 inch, down to molecular size) by such processes as crushing, grinding, abrading, and atomizing.“Condensoid"" is a convenient term for dispersoids formed by condensation, and ""disintegrasoid"" for those formed by disintegration. Solid condensoids are sometimes called ""fume,"" solid disintegrasoids ""dust,"" liquid condensoids ""fog,"" and liquid disintegrasoids ""mist.""5/"

May 1, 1942

By James R. Kerr

This study reviews the sulfur and suliuric acid industries in Eastern United States with emphasis on patterns of consumption and marketing. Output of sulfur in the East is relatively small, and most of the area's sulfur requirements are met by gulf coast Frasch sulfur. Over the long ten recovered elemental sulfur from sour natural gas and petroleum may become the East's major source of sulfur. In 1958 sulfuric acid manufacture consumed over 80 percent of the area's sulfur requirements. The leading uses for sulfuric acid were the manufacture of superphosphates and chemicals. Over the years, unit requirements for sulfur and acid in many major markets have been reduced through improved technology, but new markets always have been developed to keep the industry vital and growing.

Jan 1, 1965

By James R. Kerr

This study reviews the sulfur and suliuric acid industries in Eastern United States with emphasis on patterns of consumption and marketing. Output of sulfur in the East is relatively small, and most of the area's sulfur requirements are met by gulf coast Frasch sulfur. Over the long ten recovered elemental sulfur from sour natural gas and petroleum may become the East's major source of sulfur. In 1958 sulfuric acid manufacture consumed over 80 percent of the area's sulfur requirements. The leading uses for sulfuric acid were the manufacture of superphosphates and chemicals. Over the years, unit requirements for sulfur and acid in many major markets have been reduced through improved technology, but new markets always have been developed to keep the industry vital and growing.

Jan 1, 1965

[This Bureau of Mines report presents results of a survey of underground mining equipment and of two demonstration programs showing the feasibility If quieting; a load-haul-dump (LHD) machine and a personnel vehicle. Typical noise levels are presented for the major machine types used in underground mines, along with estimates of the noise overexposure of miners who operate or work near these machines. General principles of noise control are explained, and the application of these principles is illustrated in the description of modifications made to the LHD machine and the personnel vehicle. The noise control package installed On the persona of vehicle lowered its noise level by 14 dBA after 4 months of operation, and inspection of the LHD machine after 2 1/2 years of operation with the modifications showed its noise level 7 dBA lower than that of the unmodified machine. Noise dosimeter measurements indicated that both machines were in compliance with Federal noise regulations for a typical shift.]

Jan 1, 1980

By Clarence Karr

AN EXTENSIVE characterization was conducted on the neutral oil components in a low-temperature bituminous coal tar. A total of tai individual compounds identified with respect to individual isomers, and at least 55 other compounds were indicated to be present. The amounts were determined in all instances. A comparison of isomeric distribution in the tar with thermo-dynamic equilibrium distribution, and kinetic distributions indicated that the composition of the tar largely reflected the structure of the coal from which it was formed. Detailed descriptions are presented for the separatory and qualitative and quantitative procedures for the characterization of the neutral oil component. These include micro fractional vacuum distillation, displacement liquid chromatography, gas-liquid chromatography, countercurrent distribution, and infrared and ultraviolet spectrophotometry. Descriptions are given for the synthesis of authentic specimens of alkylindenes, The ultraviolet and infrared spectra of 134 polycyclic compounds, ranging from alkylindenes to alkylphenanthrenes, either found in the distillable neutral oil, or thought likely to be present, are also given.

Jan 1, 1967

By William R. Barton

Anthracite has been mined from the Narragansett Basin of Rode Island and Massachusetts sporadically, and with limited success, for more than 170 years. Beginning in 1974, interest in the coal of the Basin was renewed because of increasing prices and supply uncertainties involving petroleum products. During 1974-77 the Bureau of Mines analyzed 28 samples of Basin coals and conducted washing tests on 20 of them. Results, reported herein, indicate that the coals are low-sulfur, moderate- to high-ash anthracites and semianthracites, suitable for physical preparation to a product generally containing less than 10 percent ash. Additional exploration, sampling and testing will be required to permit appraisal of the potential value of the Narragansett Basin coal resources.

Jan 1, 1977

By BUREAU OF MINES

In 1948 the United States became a net importer of oil. Coupled with an unprecedented domestic production of 5,900,000 barrels daily, imports approximating 500,000 barrels made available a total supply of 6,400,000 barrels a day. Thus, by a herculean effort, the oil industry was able to meet an extraordinary demand at home and, in addition, to ship abroad almost 460,000 barrels daily of petroleum and products. The country’s oil position now differs greatly from that prevailing at the beginning of World War II. Then, actual oil production averaged about 4 million barrels a day, and productive capacity probably was greater than 5 million barrels a day. As the demand of the military and industrial machine grew with the rising tempo of the drive toward victory, the United States not only met its own needs but produced about two-thirds of the total oil requirements of the Allied Nations, excluding Russia. As a people, we can be deeply grateful that the Nation’s petroleum resources were adequate and sufficiently developed to support such a tremendous effort. Even in those critical hours when immediate needs were the paramount issues, a prudent Congress paused to contemplate the importance of an assured long-term supply of liquid fuels. From these deliberations came the Synthetic Liquid Fuels Act of 1944, which authorized research and development work on new sources of oil – coal, oil shale, and agricultural and forestry products. Since World War II, a civilian demand for 6 million barrels of petroleum products has become the order of the day. By drilling as many as 39,000 new wells a year, the production rate has increased enough to meet domestic requirements by a bare margin. Some imports were necessary, however, to fill both domestic and foreign demands, and these doubtless will increase. Is this policy of exploration within the United States and the development of oil in foreign countries adequate insurance for the fulfillment of our future national needs? This question has two aspects – one purely civilian and economic in character and the other significant from the standpoint of our national defense. There are now approximately 4,000 producing oil fields in this country. At first thought, it would appear that production could decline in a considerable number of these fields without materially affecting the overall daily output. However, 48 percent of the oil comes from only 111 major fields which contain 60 percent of the total proved domestic reserves. It is apparent, then, that the flow from large fields – having proved reserves of 100 million barrels or more each – must be sustained if daily production is to be kept at the present levels. Essentially, this means that new major fields must be discovered about as rapidly, or perhaps more rapidly, than the older ones lose productive capacity. From 1940 through 1947, only eight major fields with estimated reserves of more than 100 million barrels each were discovered and proved – an average of one such field a year. The total estimated reserve of these eight fields was less than 1 year’s supply at the present rate of use. As drilling continues, some existing fields ultimately will prove reserves larger than those now known. Without a pronounced increase in the number of major discoveries, however, the prospects for increasing our present productive level are not encouraging. Any gap that appears between domestic productive capacity and demand could be filled with supplies from proved oil resources abroad. Assuming cheap pipeline and tanker transportation to the United States, freedom from exorbitant taxes and charges...

Jan 1, 1949

By P. A. Kennedy

An environmental assessment or impact statement for onshore waste disposal under the Notional Environmental Policy Act is expected to occur with the development of commercial deep seabed mining. An environmental assessment was conducted in order that testing and refinement of nodule waste disposal techniques can he completed prior to 1988, when commercial seabed mining can begin under U.S. legislation. Within this study three classes of process and four classes of waste disposal technique were identified, and five sites were selected as representative of first-generation nodule operations. Each realistic site/process/disposal technique combination was compared against potential effects to determine important characteristics of the rejects and the sites. Regulatory requirements were also considered at each site to identify important issues and their effect on the permitting process. Principal conclusions in the report are the following: (1) uncertainties exist in the regulatory regimes for hydrometallurgical process tailings, primarily regarding classification as hazardous waste; (2) slogs from nodule processing are expected to be inert and relatively easy to dispose of at all sites; and (3) additional physical and chemical information on properties of rejects from all processes is necessary to predict environmental effects.

Jan 1, 1982

By Edward A. McClatchie

A methane monitor that complies with 30CFR75.313 has been designed and fabricated using a novel pressure modulated infrared absorption technique. The methane monitor met or exceeded in performance all of its target specifications. The monitor was operated continuously during production mining for the entire duration (45 days) of the in-mine test; no failures occurred during the test. The monitor was regularly checked with calibration gas and no shifts in calibration were found during the in-mine test. Operating principles, performance data and electrical schematics are included in the report.

Jan 1, 1976

By Donald W. Mitchell

Research shows that water neutralizes the explosion hazard of coal dust when present in sufficient quantity and when intimately mixed with the dust. The quantity of water required to neutralize coal dust and coal-rock dust mixtures is about equal to the limiting moisture adsorptive capacity of the dust; the adsorptive capacity increases with increase in the fineness and volatile content of the coal. Pools of water or high atmospheric humidity do not reduce the explosion hazard. Although wetted dust is less dispersible than dry dust, poor dispersibility cannot be relied on as the sole safeguard against explosion. Dust mixtures that contain water in excess of their limiting adsorptive capacity are dispersed and ignited by severe initiation sources. Pure coal dust adsorbs water with difficulty and retains water poorly; adsorption and retention is increased by the addition of rock dust the coal; the rock dust agglutinates wetted coal and assures that incombustible is present should drying occur. Therefore, it is advantageous to rock-dust wet areas in bituminous coal and lignite mines. When coal-rock dust mixtures are wetted and subsequently dried, the explosion hazard is about the same as for dust which was not wetted.

Jan 1, 1962

By William E. Young

There are many large rhodonite-bearing veins containing manganese in the Eureka-Animas Forks area of the San Juan Mountains in Colorado. The Sunnyside vein is the largest known vein in the area. As observed on the surface, the vein is mineralized over 8,000 feet and attains a maximum width of 200 feet. The average width of the vein and its branches and ramifications is 58 feet in the area that was mapped in detail. The weighted-average analysis of surface and underground samples from the northeastern extension of the Sunnyside vein is 8 percent manganese. Most other known veins in the area have a similar manganese content. The Hidden Treasure vein lies southeast of the Sunnyside-No Name-Mastadon vein. The weighted average of the analyses of surface and underground samples from this vein is 13 percent manganese. Exposures of the Scotia-Silver Chord vein are visible over a strike length of 4,000 feet on Treasure Mountain. Diamond-drill holes show that the vein contains 10 percent or more manganese to a depth of 400 feet. The vein has an average width of 28 feet. The Independence vein is exposed on the surface for a distance of 600 feet and has an average width of 6 feet. Three cut samples taken across the vein had an average content of 20.7 percent manganese. Sampling of the outcrops of eight veins in the Placer Gulch area also indicates manganese. Numerous other veins cropping out in the surrounding area are similar to the outcrop of the Sunnyside vein system mineralogically and are worth investigating.

Jan 1, 1966

By Shouchen Dun, Zong-Ming Li

Manipulation of hand-held objects in 3D space is a complex task. Understanding how individual digits interact with a hand-held object provides helpful information for hand tool designers, researchers, clinicians, and occupational therapists. At the object-digit interface, the contact mechanics can be represented by three force and three torque components. Six-component force/torque transducers can register all the three forces and three torques at the digit-object interface, and therefore are advantageous in the study of manipulation mechanics. The large number of force and torque signals from multiple force/torque transducers are difficult to interpret and therefore making experimental research of manipulation a challenging task. The purpose of this study was to develop a 3D visualization tool for the investigation of the contact mechanics at the object-digit interfaces during manipulation tasks. Methods A 3D stick-figure hand model was created based on digitized 23 anatomical landmarks of the hand. Five miniature 6-component force/torque transducers (4 × Nano17 for the fingers, 1 × Mini40 for the thumb, ATI Industrial Automation, NC) were used to record force and torque data at the tips of individual digits. Thirty channels of force/torque signals from the transducers were collected by a 16-bit analogue-digital converter (PCI-6031, National Instrument, Austin, TX) installed in a computer. The transducers were mounted on a custom-made rectangular aluminum handle for object manipulation. Coordinate frames were established at each transducer, on the handle, and at the base of the MicroScribe digitizer. To visualize the force vectors at the digit-tips, the coordinates of the hand landmarks in the MicroScribe coordinate frame and the force vectors in local transducer coordinate frames were transformed to a common coordinate frame defined on the handle. One healthy right-handed, male subject participated in the experimental study. During the tests, the participant sat in a chair by a testing table. The forearm was strapped to an arm holder in neutral rotation position. The instrumented handle was fixed on the testing table by a C-clamp through an adapting plate. With the hand of the subject gripped on the instrumental handle, the landmarks of the instrumented handle and the transducers, as well as the anatomical landmarks of the hand were digitized using the MicroScribe digitizer for the purpose of coordinate frame establishment and transformation as described above. The subject performed three different maximum isometric voluntary contraction tasks: (1) grasping, (2) rotating in pronation, and (3) lifting. Results The 3D hand model and representative force vector clusters in a single trial of grasping, rotating, and lifting tasks are shown in Figure 1. Each cluster was formed by displaying all the 3D force vectors during the period of “stabilized” maximum effort in a trial. The magnitude and

Jan 6, 2006

By Anu Martikainen

Utilization of belt air in underground coal mines has been discussed extensively during the last decade. The Final Report of the Technical Study Panel on the Utilization of Belt Air and the Composition and Fire Retardant Properties of Belt Materials in Underground Coal Mining formed by the Miner Act of 2006 recommends research on leakage, use of booster fans, and escapeway safety. This paper discusses the role of ventilation modeling in evaluating primary escapeway pressurization in a three-entry development system to improve emergency escape in a coal mine using belt air. The intake entry of the NIOSH Bruceton Experimental Mine was pressurized using a 1.1 m (42 in) diameter, 37 kW (50 hp) fan. The work details air movement in the simulated three-entry system and the resulting leakage patterns. Three mine ventilation software packages were compared to analyze their performance in predicting the airflows and leakage conditions with different fan settings. NIOSH researchers found that the measurement results correlated well with the results of modeling.

Jan 1, 2010

By G. W. Jones

During the course of an investigation by the Bureau of Mines into the causes, behavior, end control of anthracite-line fires, it was observed that the carbon monoxide disappeared from a scaled fire area much more rapidly than could be explained oil the basis of leakage of gases. Two suggestions were offered for this high rate of disappearance; (1) That the carbon monoxide was oxidized at temperatures below 150° C, by either the anthracite or its ash (tests on many anthracites have shown that at temperatures above 150° C carbon monoxide is liberated in the oxidation products when air is passed through it); (2) that the carbon monoxide was oxidized by micro-organisms present in the sealed area.

Jan 1, 1939

By A. C. Richardson

The mine of the Porter Coal Co. is located at the town of Porter in the northwestern part of Jefferson, County, Ala., about 20 miles west of Birmingham. The operations in this mine are confined to the middle and bottom benches of the Mary Lee bed. The coal from the Porter mine is handpicked and washed before being placed on the market. The handpicked lump coal and the washed egg and nut, coal are sold chiefly as domestic and steam-raising fuel. The coal finer than 1 inch is washed in 2-compartment jigs and utilized in the manufacture of metallurgical coke. The coal company has found that, when coal ranging in size from 1 to 0 inch is washed in jigs, a considerable amount of high-ash material finer than 3/16 inch remains in the washed coal. This paper gives the results of an investigation which was conducted for the purpose of determining the washing characteristics of the through 316-inch raw coal and the extent to which the ash might be reduced by means of coal-washing tables. This investigation has been made in connection with an. extensive study of the coal-washing problems now being conducted by the United States Bureau of Mines and the University of Alabama, with the cooperation of the coal-mining companies of the State.

Jan 1, 1933