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By James J. Hanslovan

Stresses that damage coal mine trailing cables were investigated to obtain a quantified description of cable-stress locations, magnitudes, and frequency of occurrence. Stresses occurring in operating mining sections were measured and observed. Answers to questions that arose during the underground investigations were pursued under controlled conditions, both in the field and in the laboratory. Cable-handling suggestions that minimize or eliminate the stresses are summarized in the form of recommendations to mine operators.

Jan 1, 1979

By Clarence Hall, CHARLES F. MUNROE

Of the common causes of the larger mine accidents, such as falls of roof and coal, gas and dust explosions, mine fires, and the misuse of explosives, all of which are often closely related, each must be studied and fought in a manner peculiar to itself. The last mentioned, the misuse of black powder and other explosives, is sometimes considered the least important of these causes of mine accidents; but its impor- tance is much greater than the statistics indicate, for the reason that the misuse of explosives is the true cause of many of the fatal mine fires, gas or dust explosions, and falls of roof that are credited to other causes. Both the quantity of explosives used and the number of purposes to which they are applied are increasing. They are now made at about 150 plants, in different parts of the United States, and the product of a single year is estimated at nearly 500,000,000 pounds. Nothing in all this material is a safe or "safety" explosive when in the hands of a careless or ignorant person; and this is true whether considered in connection with the shipment or the use of these explosives. In addition to the large losses of life and property resulting from an improper use of explosives in mining, the recent statistics of the railway bureau for the safe transportation of explo- sives have shown more than 400 persons killed or injured and over $3,000,000 worth of property destroyed by explosives in transit by rail. The fact that three years of cooperative effort under the wise supervision of this bureau has reduced these losses to almost nothing encourages the hope that similar cooperative effort may likewise greatly lessen losses of life and property from the use of explosives in mining. The additions to the large death roll of our mines make a recurring appeal to the public for fair treatment of the coal-mining industry, and to the miner and the manager that they join in every possible effort for greater safety. It may never be possible under conditions such as exist to-day to prevent mine accidents entirely. Little can be accomplished in that direction by either the operators or the miners working alone, but experience in all countries shows that

Jan 1, 1911

By E. V. Cilento, K. A. DiGregorio, R. C. Lantz

"K. A. DIGREGORIO, E. v. CILENTO, AND R. c. LANTZ. Measurement of superoxide release from single pulmonary alueolar macrophages. Am. J . Physiol. 252 (Cell Physiol. 21 ): C677-C683, 1987.-An electrooptical method was developed to quantify superoxide (02) release from single rat pulmonary alveolar macrophages (PAM) during adherence to the bottom of a culture dish. This was done by measuring the reduction of nitro blue tetrazolium (NBT) to a diformazan precipitate at 550 nm from videorecorded images of individual cells. Temporal changes in cell optical density, which are proportional to the mass of diformazan produced, were calculated from videophotometric measurements of the change in light intensity over individual cells. Total diformazan produced increased 78 and 1263 with an increase in NBT from 0.5 to 1.0 and 2.0 mg/ml, respectively. Total diformazan produced and maximum rate of production among individual PAM varied two- to threefold providing strong evidence for heterogeneity in 02 production. Specific inhibition of 02 production by superoxide dismutase, iodoacetate, and chlorpromazine significantly reduced the total diformazan produced and maximum rate of diformazan production. Hydrogen peroxide was not involved in NBT reduction, since catalase alone did not significantly change diformazan production. This novel method to quantify 02 release from single PAM should be valuable in analyzing heterogeneity and single cell kinetics of O; production, in assessing the effects of exposure of cells to particulates on O; release, and in relating release to electrophysiological measurements.rat; nitro blue tetrazolium; macrophage heterogeneity; single cell kinetic PULMONARY ALVEOLAR MACROPHAGES (PAM) protect the lungs by phagocytizing foreign debris and bacteria (24). This process involves ingestion as well as destruction of foreign matter. Phagocytosis is usually accompanied by a respiratory burst that increases cellular oxygen consumption and glucose metabolism in the hexose monophosphate shunt (7), which leads to the release of highly reactive oxygen metabolites at the surface of the · plasma membrane (6, 27). These agents have been implicated in the killing of bacteria by phagocytes (22), but have also been shown to be toxic and have been linked to cancer, emphysema, arthritis, diabetes, and other diseases (17, 22, 30). Toxic effects may be a result of either an abnormally low production of metabolites, resulting in damage to lung tissue by respirable bacteria and dusts, or an abnormally high production, resulting in direct damage to lung tissue by metabolites themselves."

Jan 1, 1989

By Joseph B. Cummings

"Occurrences of fluorite on the Packard property were first examined by an engineer3/ of the Bureau of Mines in July 1943 as the result of receipt of an application for an access road. In August of the same year the showings were examined by a geologist4/ of the Federal Geological Survey. The property was again examined by an engineer5/ of the Bureau of Mines in March 1944. This last examination resulted in a proposal that access be gained by construction of a truck trail and that the Bureau of Mines undertake to explore the fluorite showings.The truck trail was constructed by the Public Roads Administration, which began the work on February 17, 1945, and completed it 8 days later.The Bureau of Mines exploratory program was completed on May 16, 1945. It consisted of stripping overburden, trenching, test pitting, tunneling, sampling, and topographic mapping.In addition to being described in some detail, the extent of the work as well as results are shown in accompanying tables and figures.Mrs. Rhoda A. Packard, Mrs. Nora 1. Cline, and C. B. Pettingill, all of Tonto Basin, Ariz., own the property, which comprises four contiguous, unpatented lode mining claims recorded at Globe, Ariz., as the Walnut and the Bluebird 2, 3, and 4. The claims are situated in T. 6 N., R. 11 E., Gila County. David L. Roscoe of Tombstone, Ariz., holds a lease and option to purchase.Access to the property is by Highway 88 from Globe, 34 miles to Roosevelt, thence 24 miles by a graded county road along the west side of Roosevelt Lake to Tonto Basin. Here the Greenback Ranch road, constructed by the Forest Service and maintained by the county, crosses Tonto Creek and continues easterly to the foothills. The truck trail leaves the road 8.5 miles east of Tonto Basin and runs 2.5 miles in a southerly direction to the property. (Fig. 1.)The fluorite deposits lie in and along a small canyon in a rough, rocky area at an altitude of about 3,400 feet, Vegetation is scant and of the usual desert variety. The summer climate is dry and hot and the winter climate moderate. Rainfall at the Forest Service Station in Tonto Basin was 11.4 inches from May 1944 through March 1945."

May 1, 1946

By BUREAU OF MINES

The approval of the U. S. Bureau of Mines when granted to a manufacturer for a gas mask is a certification that the particular device has been submitted to the Bureau of Mines for inspection and test and has been found to meet that bureau's published minimum requirements for safety , durability , and satisfactory performance . Any de- Gas masks are approved by the Bureau of Mines only as a complete unit or assembly of parts , as canister , facepiece and harness . This is in order that responsibility for rigid adherence to the bureau's requirements may be definitely located and not divided . vice marketed under this approval must be a unit composed of parts identical in detail of design , assembly , workmanship , and quality , and produced under the same control and inspection as the original device to which approval has been granted . The particular parts which comprise the approved assembly are designated in a letter to the manufacturer at the time the approval is granted . In recent years they are also specified in the approval plate authorized for use in connection with the sale of the device . Each part permitted in the assembly is legibly marked by name or number for the guidance of users of masks in ordering and identifying approved parts when making repairs , and thereby maintaining their equipment as an approved device . In view of the foregoing , any change in the design of parts or deviation from the permitted assembly of parts would violate the conditions under which approval was granted and the device would not be considered as meeting the approval requirements of the Bureau of Mines . The U. S. Bureau of Mines has been frequently requested to interpret the approval status of a gas mask assembled from parts which have separately met its requirements as components of two or more approved devices but which in the form of a complete unit has not been submitted for tests or been granted approval . Responsibility for the elements and for their proper assembly is in such case divided . Such assembled units have no status as permissible equipment under the Bureau of Mines system of schedules . The reasons underlying this policy are that the approval is granted only to some one who assumes responsibility for the whole and that the details of assembly and coordination of parts are considered to be important to the satisfactory performance and safety of the device .

Sep 1, 1932

By R. V. Holmes

The properties of the Colorado Copper Co. in Sinbad Valley, Mesa and Montrose Counties, Colo., were rehabilitated and sampled by the Bureau of Mines in October, November, and December 1942. The several deposits were reexamined in March and April 1945 to obtain information disclosed by company work after December 1942. The development program included surface trenching, rehabilitation of several edits, and channel sampling of the exposures. Assay determinations wore made on 204 samples from the surface and underground workings. The results are given in the appendix. Several copper deposits in the Sinbad Valley area are similar in origin. The host rocks are sedimentary and mice in age from Pennsylvanian to Cretaceous. The Colorado No. 3 deposit occurs in the Cutler formation, which consists of many small lenses of conglomerate, sandstone, and shale. Mineralization is closely associated with faulting. On the Pyramid group the enrichment occurs in a zone of fracturing and jointing end also spreads into the adjoining sandstone. The ore deposition on the Copper Rivet claim is associated with a fault zone and is confined to en area above the contact of the Dolores-Wingate formations. Mineral deposits on the Sinbad claims occur at intersections of faults with blue-gray Pennsylvania limestone. Copper enrichment occurs along faults and as replacement of the surrounding limestone. Metallurgical tests indicate that ores from the Colorado No. 3 and Pyramid claims can be treated successfully by leaching with sulfuric acid. This method cannot be applied to ores from the Copper Rivet or Sinbad deposits because of high calcite content. Flotation tests at Boulder City, Nev., showed a recovery of less than 60 percent with a 14.24 percent copper concentrate.

Jan 1, 1952

By Henry M. Harris, John E. Kelley, Thomas D. Roberts

A penetrometer apparatus for measuring viscosity of glass at temperatures up to 1,450 ° C was developed for use in establishing the viscosity coefficients required for high- temperature forming of ceramic materials . The major advantage of the method is that it can be used with samples of almost any shape or size without the necessity of forming or measuring shapes to close dimensional tolerances . Also , it has proved accurate in the range of 106 to 109 poises , a gap between the normal limits of other methods . The device , which operates on a single penetrometer principle , was used to determine the absolute viscosity coefficient of substances in centimeter - gram- second units of poises instead of relative penetration - rate units as with other penetrometers . Penetration of the viscous sample was sensed with a linear , variable differential transformer . The output of this transformer was recorded versus time , and the penetration rate was used in calculating the viscosity coefficient . The general equation relating penetration rate and viscosity coefficient was found to be 11 = F ( ln L/a 0.72 ) 2 π UL · where is the viscosity coefficient in poises , F is the penetrator load in dynes , L is the penetration depth in centimeters, a is the penetrator radius in centimeters and U is the penetration rate in centimeters per second . The penetrometer was tested using a standard viscosity sample of sodalime - silica glass obtained from the National Bureau of Standards ( NBS ) . Values obtained at several temperatures all agreed within 10 percent with comparable data calculated from the Fulcher equation derived by NBS for this glass . Equivalent accuracy was obtained with other glasses used to evaluate the apparatus .

Jan 1, 1964

By S. M. Molloy

The postwar demand for insulating material such as mineral wool, in-creased in proportion to the rapid construction of new buildings, placing an enormous burden on the existing mineral-wool industry both in known sources of raw materials and in available plant facilities. In view of the increased demand on the industry, the Bureau of Mines in its Mississippi Valley Experiment Station" Rolla, Mo., undertook an investigation to aid the industry by establishing resources of raw materials through actual laboratory wool-blowing tests and by developing certain methods for evaluating the physical proper-ties of a mineral wool. As material was received from the public, laboratory-evaluation technique had to be developed, the results of which would reflect in the mineral-wool-industry standards. The methods of testing used by the mineral-wool industry, not only would have required a pilot-plant installation capable of producing a large tonnage of mineral wool, but each wool-blowing campaign would have been very expensive and necessitated considerable personnel and equipment. The present laboratory wool-blowing equipment can produce as high as eight wool-blowing campaigns a day. The nature, simplicity, and size of the physical testing equipment permit testing as small a sample of wool as 25 grams and give information as reasonably accurate as in a 40-pound bag of wool. The purpose of this report is to describe the laboratory method of production and the evaluation of the physical properties of small quantities of mineral wool. Considerable work has already been done, and the interest of the public and industry is measured in the number of samples being submitted for testing.

Jan 1, 1948

By Glenn L. Cook

Correlations between mass spectra and molecular structures of 186 organic sulfur compounds are discussed. The olefinic ions, the alkyl ions, the CnE2n+1 ions, the m/e 61 ions, and the m/e 35 ions in the spectra of thiols are related to molecular structure. In the spectra of sulfides, the olefinic ions, the m/e 61 ions, the m/e 35 ions, the CnH2n+1S+ ions, and the CnH2n+1SH+ ions are correlated with molecular structure. For disu1fides, the correlations relate HSSF+& and RSSH+ ions to molecular structure. Base peaks of alkylthiophenes are correlated to their molecular structures. Some unimolecular reactions of sulfur compounds in the mass spectrometer are considered. A cyclic intermediate is suggested for the reaction which produces m/e 47, CH3S+, and m/e 48, CH4S+, ions in the spectra of sulfides. An expanded ring is suggested as a possible intermediate in the reactions of thiophenes. Heats of formation of sulfur-containing ions and their appearance potentials are presented in tabular form. Ionization potentials for sulfur-containing radicals and molecules are also given. Discussion of the spectra, tabulated in the appendixes, provides an insight into the relationship of the molecular structure of a compound to the mass-to-charge ratios and the intensities of the ions in its mass spectrum. Correlations of the mass spectra with molecular structures are empirically developed by observing regularities in the spectra of the reference compounds. Correlations extend the usefulness of mass spectra because they can be employed to determine the molecular structure of an unknown compound.

Jan 1, 1965

Develop a mobile manipulator that one person can use to lift and maneuver 50- to 600-pound loads. It can be used in maintenance shops and mines to reduce lifting accidents (Figure 1 and 2). Background Lifting heavy items is one of the leading causes of injury in the workplace. Mine Safety and Health Administration statistics showed that, in 2004, back injuries accounted for over 20% of all injuries (1,699 cases) and resulted in 110,000 lost days of work. Forty-one percent of those injuries resulted from materials-handling or maintenance activities.1 In addition to back injuries, lifting injuries include hernias, ruptures, sprains, and strains resulting from losing control of the item being lifted. Factors associated with accidents are weight of the item being lifted, awkward postures, inadequate handholds, and the working environment itself. High accident rates were noted when lifting items that ranged from 50 to 600 pounds, particularly in tight working quarters where maneuverability was critical. Research indicated that a mobile lifting arm would eliminate many lifting accidents in environments where other lifting devices (fork lifts, overhead cranes, mobile A-frames) would not be practical. NIOSH has built a first-generation mobile manipulator unit designed to be used on hard, level floors such as in a shop. The complexity of motion, number of moving parts, compact design, and design constraints of the manipulator required advanced computer-aided design work (Figure 3). As a result of the design work, thirty-eight claims are included in the patent applications. NIOSH will be conducting field trails and working with manufacturers to put the manipulator into industrial use.

Dec 1, 2006

By D. J. Parker, D. Harrington, L. H. Harrison

The necessity for protection against the hazards of lightning manifests itself from time to time in the mining industry by reason of loss of life, damage to electrical equipment, fires in surface structures at mines, and accidents in the handling and use of explosives. This paper is intended to assemble, correlate, and present some of the salient. points embodied in the available literature on the subject and at the same time give some factual data concerning instances of such loss of, life and damage to property, with special application to the mining industry The annual loss of life and destruction of property by lightning is considerable; the former may be prevented to a limited extent, though use of common sense as to exposure is required and not always followed; the latter can be prevented to a considerable degree. The manufacturers of electrical equipment,, through improved types of lightning arresters,, have done much toward the protection of electrical equipment, with consequent safeguarding of life and of property. Education based on unfortunate experiences has gone far to discourage the handling of explosives and blasting accessories during thunder storms, especially in open pits and quarries, and to a much smaller extent in underground workings. The lowly lightning rod plays an important role in the protection of certain types of buildings (especially isolated buildings), stacks, monuments, and other structures. LIGHTNING PHENOMENA In 1751, Franklin proved that lightning was simply a visible display of electricity - an extended spark; and until a generation ago little had been added to his exposition, to define the various phases of the phenomenon. Matters pertaining to lightning are discussed in the following references:

By Doris M. Hyde

The impact of mining activities on the economy in both 1983 and 1984 was minimal. The most recent available data on the gross domestic product (GDP) indicated a level of $1.6 billion in 1983.2 The estimated value for the production of cement, aragonite, and salt was about $17 million in that year, down from the estimated $20 million in 1982. No data are available on the economic impact of the large petroleum refinery at Freeport on Grand Bahama Island, but it represents the major mineral-related activity. Cement production remained at only a fraction of the 800,000 tons per year of plant capacity. The offshore search for hydrocarbons continued in 1984, and some companies were about to enter the third year of seismic and geological surveying around Andros and Grand Bahamas Islands. Getty Oil (Bahamas) Co. Inc.; Breoco Ltd., a subsidiary of REO Development Corp. of Tulsa, Oklahoma; and Natomas Petroleum (Bahamas) Ltd. were the first companies to be awarded exploration licenses. These companies were committed to drilling at least one well before the end of the third exploration year. Other companies actively engaged in exploration included Exxon Corp., Atlantic Richfield Co. (ARCO), Chevron Oil Bahamas Ltd., and Esso Oil Bahamas Ltd. Geophysical Services Inc. (GSI) of Dallas, Texas, and Petroleum Services (Bahamas) Ltd. of Englewood, Colorado, ran another seismic survey line during 1984. This 1,533-mile line was in the Great Bahama Bank and Cay Sal Bank areas off the southeast Florida coast, and tied in with a 4,530-mile program GSI ran in 1981-82. These surveys were nonexclusive and publicly available through GSI.

Jan 1, 1986

By Joseph W. Town

The Bureau of Mines conducted studies related to SO2 air pollution to determine attritioning rates, SO2 sorption rates, and sulfur loads that could be obtained on commercial alkalized alumina sorbent pellets. Fluidized-bed attritioning rates ranged from 0.025 pct/hr for alkalized alumina with a crushing strength of 4 kg to 0.075 pct/hr for 0.5 kg crushing strength mate¬rial. Airlift attritioning rates ranged from 0.50 pct/hr for 3 kg crushing strength alkalized alumina to about 3 pct/hr for 0.5 kg material. Attritioning rates for the commercial alkalized alumina were comparable to those obtained for sorbent pellets prepared in the Bureau of Mines laboratory. Sorption rates were related to S02 concentration in flue gas, temperature, and presence of nitrogen oxides in the gas stream. Sorption rates at 300° C were 0.35 X 10-6 gS/gp/sec (grams sulfur per gram pellet per second) in 0.045 pct so, gas, 5.1 x 10-5 gS/gp/sec in 0.34 pct SO2 gas, and 65 X 10-5 gS/gp/sec in 10 pct SO2 gas. For the 0.34 pct S02 gas, sulfur loads of 0.10 gS/gp (the projected load for regeneration) were obtained in 47 min at 130° C and in 116 min at 300° C. The presence of either NO or NO2 in the 0.34 pet S02 gas increased the SO2 sorption rates 2 to 3 times at 300° C, but had no effect at 130° C.

Jan 1, 1969

By J. E. Pahlman

As part of its goal to minimize the requirements for mineral commodities through conservation and substitution, the Bureau of Mines is conducting research to determine the resistance of alumina refractories to corrosion by alkali-containing slags that could result from burning of the abundant Western lignites in metallurgical operations. Static corrosion tests were performed at 1,000° to 1,350° C and dynamic tests were performed at 1,400° to 1,600° C to investigate the stability of refractory specimens in slag environments. In general, the degree of refractory attack increased with decreasing alumina content in the refractory and with increasing alkali content of the lignite ash. The parabolic kinetics observed in static tests suggested that a reaction product layer is formed through which ionic diffusion must occur to sustain the reaction with the refractory material. The linear kinetics observed in dynamic tests in high-viscosity slags indicated a shearing of the reaction product layer by viscous slags. The observed lesser attack of refractories by low-viscosity slags can be explained on this basis. Two 99-percent-alumina refractories and two 90-percent-alumina refractories formed an expanded protective layer with the more viscous slags but not with the less viscous slags. Corrosion of 90-percent-alumina refractories increased exponentially with temperature. In refractories with the same nominal alumina content, those that contain a combination of a-Al203 and mullite (3A1203?2Si02) have better corrosion resistance than those containing a combination of a-Al203, cristobalite (Si02 mineral), and mullite. In alkali environments (1,300 to 1,400° C), 90-to 99-percent-alumina refractories are recommended for use as furnace linings.

Jan 1, 1980

By Kung-Lee Wang

The 1963 performance of the United States economy was impressive. The year was one of continued growth unmarred by a recession. By the end of 1963 the economy's expansion had already lasted almost as long as the 1954-57 upswing, and the net gain in output since the trough in activity in early 1961 compared favorably with most earlier postwar cyclical advances. There was no indication of any slow- down at yearend. Both gross national product (GNP) and national income in 1963 were 5 percent higher than in the previous year. GNP totaled $584 billion, a gain of $28 billion over 1962. Real output of goods and services rose 3.4 percent over the year. Price increases continued to be moderate. Production, employment, personal income, and corporate profits all registered new but unemployment continued high at 5.5 percent and the prospects for improvement remained poor. The economy again failed to use its full potential. Current value of mineral production kept pace with the economy. The constant dollar value of mineral production gained more than real GNP because of the relatively stable price of minerals. Mining production achieved a new high in 1963. Steel production totaled 110 million tons, 12 million tons above 1962, making 1963 the first 100- million-ton year since 1957 and lifting the steel-associated minerals group upward. The gain in ferrous metals mining was insufficient to compensate for the decline of nonferrous metals mining resulting in an insignificant decline in the metal mining total as a whole. The upsurge of construction material minerals output, with an assist from chemical and fertilizer minerals, accounted for peak production of

Jan 1, 1964

By Sumner M. Anderson

THE ENORMOUS contrast between the mineral economy of Cuba in 1963 and in 1958 was the result of the overall Political changed to which the total economy of the country was intimately lined. Creation of the Cuban Mining Institute (Instituto Cubano de la Minería) to direct all mining activities in the country was an early act of the new Government after the revolution on January 1, 1959. During the next 2 years, the Government confiscated foreign holdings,2 including Unite States investments exceeding $1 billion in value. Foreign mining and metallurgical technicians-predominately from Communist areas-were brought in to reorganize the mineral industries. On January 3, 1961, diplomatic relations between Cuba and the United States were severe and then on May 2, Cuba announced its full-fledged membership in the so-called Communist Bloc. Fifty-four international treaties assured Cuba of Communist economic support, technical and financial assistance, machinery, raw materials, and manufactures. The Soviet Union agreed to buy some Cuban mineral products, and Czechoslovakia stated that it would buy all mineral production offered for the next 20 years, but in both cases at prices said to be much lower than the world market. The mineral productivity segment of the mineral economy during and since the period of political metamorphosis, has withstood the political disruption better than has the economy as a whole, but with no direct measure of the magnitude of its cost. The overall economic record is marked with steady deterioration; the annual average per capita income has dropped from $374 in 1957 to $185 in 1963, when Cuba's deficit with the Soviet Union alone reached an admitted $1 billion.

Jan 1, 1964

Ecuador a gross domestic product (GDP) grew 8% despite a slowdown in production and sales of petroleum, the dominant economic sector. Crude petroleum exports, which amounted to about 35% of total exports in 1977, were valued et $484 million,2 a decrease of 14% from 1976 values. Petroleum export sales were depressed because foreign buyers were somewhat uncertain that State-owned Corporación Estatal Petrólera Ecuatoriana (CEPE) held legal title to the oil until final settlement with Ecuadorian Gulf Oil Corp. In addition to the legal complication, Ecuador maintained a relatively high export price for oil until late in the year. There was also a shrinkage of traditional U.S, markets owing to the Alaskan pipeline becoming operational and an increased availability of Mexican supplies. The export market was also affected by increased domestic production in Peru and Chile, which lessened their import needs, and the pressure of greater competition from the Middle East in supplying crude oil to Caribbean refineries. About 20.4 million barrels or 40% of Ecuador's total crude exports went to the United States. Only 27 wells were drilled in Ecuador during L977; of these, 16 produced oil, 3 were dry holes, and 8 were suspended. About 31 wells were planned for 1978. Three new oilfields were discovered during 1977; two by CEPE in northeastern Ecuador and one by the Argentine State oil company Yacimientos Petraliferos Fiscales (YPF), operating in Ecuador under a service contract. CEPE's two discoveries tested at 5,000 and 1.450 barrels per day, respectively. The YPF discovery tested at about 1,000 barrels per day. Ecuador altered its position regarding

Jan 1, 1981

By Arnold P. Pipilen

In a study of the principal factors affecting the transport of coal-water mixtures through a centrifugal pump and a pipeline, the interrelation between solids concentration, velocity, and pressure drop was established for a bituminous lump coal (minus 2 inch) in concentrations up to 48 weight-percent. An optimum concentration was found to exist for maximum capacity of a given pipe-line, and for minimum energy requirements per ton of coal. Coal size degradation by particle fracture took place in the pump; abrasion and attrition to form fines took place in both pump and line. A novel system of studying flow of solid-liquid mixtures in pipelines by the determination of relative sound intensities was developed.

Jan 1, 1966

By David Schlain

A small alumina reduction cell with a graphite crucible and boron nitride liner was developed by the Bureau of Mines as the initial phase of a study of the reactions which occur in the reduction of alumina by the Hall-Heroult process. Operating conditions in the cell such as temperature, time, current density, electrolyte composition, and electrode materials may be varied easily. Aluminum was produced in the cell at a current efficiency of about 75 percent and a cell voltage of 2.7 volts. Although the data are not wholly conclusive, the operation of the cell did not appear to be greatly affected by large changes in temperature, electrode spacing, current density, and alumina concentration in the electrolyte.

Jan 1, 1963

By Jalna R. Zatko

The Bureau of Mines has developed and constructed an apparatus that is capable of measuring concentrations of high-molecular-weight polymers in solution at 10 ppm and less. A means for determining low concentrations of polymeric solutions was devised that was independent of slight fluctuations in solvent quality in order to measure polymers in effluent prior to recycling of the recovered solution. The concentrations of polymers ore related to a measured pressure drop observed during turbulent flow of the solution. Low concentrations of polymers of ethylene oxide and acrylamide (frequently used as flocculants for clay waste systems) in aqueous and salt solutions have been successfully measured on the apparatus constructed by the Bureau.

Jan 1, 1981