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By Larry A. Haas

The U.S. Bureau of Mines is investigating ways of enhancing the high-temperature softening-melting (HTSM) properties of domestic taconite pellets. These properties, which are important for determining the performance of pellets in blast furnaces, include pellet bed contraction, pressure drop, S-value (area under the pressure-temperature curve), and softening and metal-slag drainout temperatures. Experiments showed that HTSM properties were related to the physiochemical properties (fired strengths and reducibilities) of pellets containing different levels of limestone and dolomite flux. Flux additions resulted in slightly lower green and fired pellet strengths, but improved metallurgical properties, such as reducibility. The influence of reduction conditions on HTSM properties was evaluated by varying the pellet metallization starting temperature and the carbon monoxide content of the CO-N2 gas mixture. HTSM property change was more sensitive to flux addition levels when metallization was initiated at 1,100° C with 20 pct CO in the gas stream. The S-value and the metal-slag drainout temperature were found to be the best criteria for characterizing HTSM properties. The optimum flux addition level was about 8 pct (4 pct dolomite, 4 pct limestone) or a basicity of about 1. At higher flux levels, a higher metal-slag drainout temperature was obtained.

Jan 1, 2010

By E. G. King

Existing thermodynamic data for compounds of the rare-earth metals are few in number and often inaccurate because, in the past, it was difficult to obtain samples that were pure enough and reasonable in cost--a situation that is rapidly improving. This paper reports the results of low-temperature heat-capacity and high-temperature heat-content measurements for cerous fluoride (CeF3) and supplies the first such published data for a rare-earth fluoride. The low-temperature heat-capacity data cover the temperature range 51°-298° K. and serve to evaluate the entropy at 298.15° K. The high-temperature heat-content data cover the temperature range 298°-1,799° K., including the temperature and heat of fusion. The results are assembled for ready use in thermodynamic calculations. Cerous fluoride is one of the important intermediate compounds in the production of cerium metal.

Jan 1, 1959

By C. C. Popoff

The growth of the aluminum-smelting industry in the Pacific Northwest, resulting from national defense requirements, emphasized a need for local sources of alumina to supplement the alumina production shipped from the East. Because supplies of foreign bauxite were being interrupted and our domestic bauxite reserves were inadequate, it was necessary to expedite the investigation of other possible sources of alumina during World War II. A program of investigation of high-alumina clay deposits in the Northwest was carried out jointly by the Federal Geological Survey and the Federal Bureau of Mines. As part of this program the Cowlitz clay deposits near Castle Rock, Wash., were explored by the Bureau of Mines in 1942-43. These deposits are near railroads, tide-water, and Bonneville Power Administration lines and within 22 to 100 miles of 4 aluminum-reduction plants.

Jan 1, 1955

By Larry A. Haas

The Bureau of Mines constructed a torsion effusion apparatus to measure the equilibrium vapor pressure of pure metals, alloys, and compounds at temperatures up to 1,500° K. The reliability of the apparatus was established by determining the vapor pressure of silver. The data obtained on solid and liquid silver in the temperature range 1,200° to 1,500° K can be expressed by the following equations:

Jan 1, 1965

By Joseph S. Coffman

The Bureau of Mines investigated the availability of barite (BaSO4) from 35 U.S. and 41 non-U.S. mines and deposits in 17 market economy countries (MEC's). This evaluation assesses the availability of mud-grade barite, and concentrates consumed by the chemicals and fillers industries. The demonstrated resources defined in this analysis totaled 130 million metric tons (Mmt) of barite (contained BaSO4), yielding a potential 115 Mmt of recoverable barite concentrates. At the 1984 MEC production rate, the evaluated resources would last about 30 yr; however, this would include production costs of up to $100/mt concentrate. An average price needed to cover all costs of production over the life of each operation was determined for both mud-grade and chemical- and filler-grade barite products. Including a 0-pct discounted-cash-flow rate of return (DCFROR), regional weighted- average total production cost ranged from $38/mt for barite concentrates in Asia to $71/mt for U.S. operations. Transportation costs have the greatest impact, contributing up to 60 pct of the total cost of production. Rail transportation costs from the mines to U.S. markets are generally significantly higher than ocean shipping rates on imports.

Jan 1, 1986

By John Nagy

This circular has been prepared for the guidance of safety engineers, shot firers, and coal-mine inspectors concerning multiple blasting with short-delay (millisecond-delay) detonators. These special precautions are suggested in addition to those normally followed in blasting, as outlined in the Federal Mine Safety Codes 5 6/ and in Miners' Circular 58.7/ INTRODUCTION The use of short-delay blasting has been proposed for promoting safety and increasing the rate of production in coal mining. Ideally, short-delay blasting, as compared with equivalent single-shot blasting, reduces exposure of the shot firer to dust, fumes, and weakened roof; as compared with equivalent simultaneous blasting, it reduces roof disturbance.

Jan 1, 1959

By K. O. Bennington

The thermodynamic properites of petalite (Li2A12Si8O20) were determined by the Bureau of Mines. The enthalpy of formation was determined by hydro-fluoric acid solution calorimetry. The values from the elements and from the oxides are ?Hf°298.15 = 2,335.8 ± 3.0 kcal/mole and ?H°295 (from oxides) = -50.60 ± 1.20 kcal/mole. Low-temperature heat capacities were determined by adiabatic calorimetry from 10.69 to 302.11 K. The derived standard entropy is S°298.15 = 111.0 ± 1 cal/deg-mole. Enthalpy increments above 298 K were measured by copper block calorimetry from 298 K to 1,193.6 K. The various experimental data were combined with other data from the literature to calculate the Gibbs energies of formation and equilibrium constants of formation over the temperature range of the measurements. Tables of enthalpies of formation and Gibbs energies of formation are given as a function of temperature from the elements and constituent oxides. The Gibbs energy of formation is ?G°f298.15 = 2,203.8 kcal/mole.

Jan 1, 1980

By R. P. Vinson

The Bureau of Mines conducted a series of tests to determine how well the Bendix BDX 60, the Gilian HFS 113U, the MSA Fixt-Flo, and the Spectrex PAS-3000 dust sampling pumps control the flow rate at 2 L/min. These tests were performed because users need to know the performance characteristics of sampling pumps to select the pump that best satisfies their sampling requirements. Long-term (6- to 8-h) flow stability at various backpressures was examined in relation to the flow control tolerance of ±5% of the flow, the level imposed by Federal regulations; four of the five Bendix pumps did not meet the criterion for this test, which was passed by all other pumps tested. Flow control recovery times were measured at transient backpressures; all pumps evaluated met the criterion for this test. The low-flow indicators of the sampling pumps were tested; only two Bendix pumps and one Gilian pump met the criterion of indicating a flow change greater than ±5%. In the pulsation flow measurement test all of the pumps passed, with pulsating flows greater than 20 Hz. The Bureau also evaluated the manuals accompanying the sampling pumps. All were judged adequate except the Spectrex manual, which was judged poor.

Jan 1, 1985

China?s New Steel Complex Postponed. - The planned $5 billion Baoshan Steel Works near Shanghai is being laid aside for 6 months to a year, and may be abandoned altogether. The second phase of construction, in which Wean United, Inc., of Pittsburgh was a major participant, has definitely been cancelled. Over $1 billion had been committed to the 6 million-ton-per-year plant. U.S. Firm Develops South African Fluorspar. - The Armco Bronne Co. of Middletown, Ohio, plans to spend $27 million to develop a fluorspar mine in the Republic of South Africa, With fluorspar reserves at 20 million metric tons, the project is planned to produce 200,000 tons Per year of fluorspar for export starting in 1983. U.S.S.R. Resumes Sales of Titanium Sponge. - Against a background of increased U.S. titanium sponge supplies, the Soviet Union is offering limited quantities of this commodity to the U.S. market at approximately $10.00 per pound, down from $25.00 per pound last year.

Jan 1, 1981

By Roger A. Dworak

This report describes in detail the work done on the development of the Time Domain Reflectometry Microcomputer (TDRM). Modifications to the FMC-Model 302A Cable Fault Locator is described in Appendix D. The TDRM unit uses an 8080 microcomputer to accurately locate major faults in low capacitance cables to within ± 1 foot when properly calibrated. Major faults in high capacitance cables are usually located within ± 5 feet. The upper limits of fault detection are <1 kilohm shunt fault and >7 ohm series fault. In practice fault detection limits are reduced to <300 ohms shunt fault and >30 ohms series fault because of discontinuities caused by cable repair.

Jan 1, 1977

By R. T. MacMillan

A number of chemical techniques have been applied to manganese ores from three areas of Aroostook County, Maine. Although large tonnages of these ores have been proved, they are low grade, and their exploitation has awaited a suitable beneficiation scheme. As conventional ore-dressing methods had failed to yield satisfactory results, attention was turned to chemical procedures. Leaching with dilute (7-percent) H2S04 extracted over 90 percent of the manganese from ore of the Dudley farm area, consuming 3.8 pounds of acid per pound of manganese extracted. Ores from the Littleton Ridge and Maple Mountain-Hovey Mountain areas were less amenable to this treatment, yielding approximately 80 and 60 percent of their Mn content, respectively. To increase the percentage extraction of manganese in the latter two ores, a number of factors were varied, including (1) acid concentration in the extracting solution, (2) ratio of acid to Mn in the slurry, and (3) preliminary heat treatment of the ore with a reducing agent. Other acids, including HNO3, HC1, and H2SO3, were tried also; however, no significant improvements in the Mn leached from Maple Mountain-Hovey Mountain ore were made. The manganese extraction of Littleton Ridge ore was raised to 90 percent by providing 9 to 11 pounds of HNO3 per pound of Mn in the ore.

Jan 1, 1954

By Seth T. Reese

THE INJURY DATA and experience at coke ovens in the United States for 1952 are presented in this bulletin under the following general sections: (A) General injury experience: Tables 1 to 9: Contain current and comparable data on operating statistics, number and classification of injuries, frequency rates, and accident agencies involved in causing injuries. Data are given for the industry as a whole, for each type of oven, and for the States in which coke is manufactured. (B) Selected injury experience: Tables 10 to 15: Contain comparable injury data in the coking industry covering 5- and 10-year periods on the number of injuries, accident agencies, and severity of injuries. (C) Historic injury experience: Tables 16 to 19: Contain data on the number of injuries, frequency rates, and employment at coke ovens from the earliest records through 1952, Operating statistics from 1929 through 1952 are given in table 19.

Jan 1, 1955

I. Domestic Production and Use: In 1981, 13 companies operated 32 primary aluminum reduction plants, with 3 firms accounting for 58% of production, Washington, Oregon, and Montana accounted for 32% of the total production; Texas, Louisiana, and Arkansas 16%; Tennessee, Alabama, South Carolina, and North Carolina 17%; other central and eastern States 35%. Based on published producer prices output of primary metal in 1981 was valued at over $7.5 billion. Aluminum consumption by 25,300 firms was centered in the East Central United States. Packaging accounted for an estimated 30% of domestic consumption in 1981, building 21%, transportation 18%, electrical la%, consumer durables 8%, and other uses 13%

Jan 1, 1982

By D. Harrington

Research in connection with occupational diseases, including silicosis or, more definitely, pneumoconiosis, has been prosecuted much more actively in North American countries during the past 5 or 10 years than in any other known period. This applies particularly to the United States, owing largely to the fact that in recent years compensation for ill health presumed to be caused by industrial work of certain kinds is being paid to a far greater extent in this country than previously. Most other countries have had occupational-disease laws for many years. Court rulings in the United States, which started 5 or 6 years ago, have given a few heavy verdicts in connection with ill health or death caused, or alleged to have been caused, by some phase of occupational work other than traumatic injury, and these have called attention to the fact that ill health and even incapacitation can be caused by some kinds of employment. With the onset of the world-wide financial depression, which resulted in permanent abandonment of many business or industrial enterprises (among them mines) in the United States, the workers frequently believed that they could expect nothing in the future from their former employers, hence they felt free to demand monetary benefits or damages because of ill health which they suffered, or thought they suffered, because of their previous employment. The result was a flood of lawsuits and. compensation claims for occupational disease, particularly where dust was involved.

Jan 1, 1938

By H. F. Yancey

The Baum-type jig used so widely to clean bituminous coals has not been adopted for anthracite. If proved suitable for anthracite, its use might lower preparation costs in some plants. Cleaning trials on a Pennsylvania anthracite in a laboratory-size Baum-type jig were undertaken by the Bureau of Mines to provide indicative information that would be helpful in determining whether the cost of a full-scale installation would be justified. Clean coal surpassing standard anthracite specifications was obtained in all sizes from Stove through No. 5 Buckwheat. Recovery effi¬ciencies were acceptable down to 3/16-inch size, but there was excessive loss of coal in the finer sizes. Thus the fine refuse produced in a commercial plant might re¬quire retreatment. A comparative cleaning trial in a dense-medium pilot plant provided a recovery efficiency only l percent higher than obtained in jigging.

Jan 1, 1957

By A. T. Iannacchione, D. G. Puglio

This Bureau of Mines study covers 25 underground mines that were active in the Upper and Lower Freeport and Lower Kittanning coalbeds in 1976. The coal ranges from low to medium volatile in rank; its primary use is for steam generation. Seven mines emit more than 100,000 cfd of methane gas; those mines are the deepest and largest producers. The methane gas content of three core samples of the Lower Kittanning coalbed was estimated by the direct method. A sample from a depth of 320 feet contained 0.5 cu cm of gas per gram, at 620 feet there was 0.8 cu cm of gas per gram, and at 1,060 feet there was 11 cu cm of gas per gram. These results suggest that methane control problems will be encountered in the future as deeper coal is mined.

Jan 1, 1979

By D. G. Puglio

This Bureau of Mines study covers 25 underground mines that were active in the Upper and Lower Freeport and Lower Kittanning coalbeds in 1976. The coal ranges from low to medium volatile in rank; its primary use is for steam generation. Seven mines emit more than 100,000 cfd of methane gas; those mines are the deepest and largest producers. The methane gas content of three core samples of the Lower Kittanning coalbed was estimated by the direct method. A sample from a depth of 320 feet contained 0.5 cu cm of gas per gram, at 620 feet there was 0.8 cu cm of gas per gram, and at 1,060 feet there was 11 cu cm of gas per gram. These results suggest that methane control problems will be encountered in the future as deeper coal is mined.

Jan 1, 1979

By Diane Schwegler-Berry, Vincent Castranova, Chang-geng Moe, Jane Y. C. Ma, Mark D. Moore, Joseph K. H. Ma, Carl J. Malanga, Ji-Hee Kane

"Effects of Bisbenzylisoquinoline Alkaloids on Alveolar Macrophages: Correlation between Binding Affinity. Inhibitory Potency and Antifibrotic Potential. CASTRANOVA, V., KANG, J-H., MA. J. K. H., Mo, C-H., MALANGA, L. J., MOORE M. D., SCHWEGLER-BERRY, D.. AND MA. J. Y. C. (1991). Toxicol. Appl. Pharmacol 108, 242-252. The Chinese have conducted extensive studies concerning the medicinal properties of plant products. In this investigation the ability of three bisbenzylisoquinoline alkaloids to inhibit particle-induced activation of alveolar macrophages was evaluated and this inhibitory potential was correlated with the ability of those drugs to bind to membrane components. Tetrandrine. i.e.. an herbal medicine used as an antifibrotic agent in China, was a potent inhibitor of particle-stimulated oxygen consumption, superoxide release, and hydrogen peroxide secretion by alveolar macrophages. Tetrandrine also exhibited substantial binding affinity for membrane lipids and alveolar macrophages. In contrast, tubocurine, an analogue with little antifibrotic potential, exhibited low binding affinity and had little effect on macrophage activation. Methoxyadiantifoline, an alkaloid of unknown antifibrotic potential, exhibited inhibitory and binding properties similar to those of tetrandrine. The data indicate that a strong relationship exists between the antifibrotic potential of these alkaloids and their ability to bind to alveolar macrophages and inhibit particle-induced activation of these phagocytes. These drugs should serve as useful probes to evaluate the role of alveolar macrophages in pulmonary fibrosis. © 1991 Academic Press, Inc.Chronic silicosis is a fibrotic disease resulting from occupational exposure to silica dust. It is manifested initially by an increase in the quantity of pulmonary surfactant (Dethloff et al., 1986). However, in later stages it is characterized by an increase in collagen formation and the development of concentric hyalinized nodular lesions in the lung (Ziskind et al., 1976). Although mechanisms for the progression of silicosis have not yet been completely defined, activation of alveolar macrophages by respirable silica particles is believed to play an important role in the etiology of this disease. Studies from our laboratory have shown that both in vitro and in vivo silica exposures result in a stimulation of macrophage release of reactive products capable of damaging the lung parenchyma (Castranova et al., 1990; Goodman et al., 1990). In addition, exposure of al¬veolar macrophages to silica results in the release of fibrogenic factors which enhance the proliferation of fibroblasts and the synthesis of collagen by these pneumocytes (Leibovich and Ross, 1976; Bitterman et al., 1982, 1983).The bisbenzylisoquinoline alkaloids, which represent the largest group among the iso-quinoline compounds isolated from the plant kingdom, are known to exhibit a broad rangeof pharmacological activities. Tetrandrine, for example, an alkaloid isolated from the root of Stephania tetrandra, has been tested for its antitumor, antihypertensive, and antisilicotic effects (Kupchan and Atland, 1973; Zeng et al., 1985; Yu et al., 1983). It is currently used in China as a treatment for angina, hypertension, and silica-induced pulmonary fibrosis (Li et al., 1981). Several related bisbenzylisoquinoline alkaloids such as methoxyadiantifoline and tubocurine have also been evaluated for medicinal effects. Methoxyadiantifoline has been shown to exhibit effects on the cardiovascular system similar to those reported for tetrandrine (Jia et al., 1988). However, to date, the antifibrotic activity of methoxyadiantifoline has not been evaluated. In contrast to tetrandrine, tubocurine, a structural analogue of this drug, has been reported to be relatively ineffective against fibrosis (Mo et al., 1982)."

Mar 1, 1992

By Donald P. Tuchman, Robert P. Vinson, Steven J. Page

Researchers at the National Institute for Occupational Safety and Health (NIOSH) have long used stationary tapered element oscillating microbalances (TEOMs®) in laboratory settings. They have served to assess the mass concentration of laboratory-generated particulates in experimental , dust chambers and they provide a reference method for comparison with other particulate- measuring instruments. Current NIOSH research is focused on further adapting TEOM technology as a wearable personal dust monitor (PDM) for coal mining occupations. This investigation&apos;s goal is to help identify, quantify, and provide means for resolving certain TEOM- related error. The present research investigated bias caused by thermal effects on filter assemblies. New filters used in the PDM for 8 h tests show an average positive bias of 25.5 pg, while similar tests of equivalent filters used in two 1400A model TEOMs show an average positive bias of 34.3 µg. The derived bias values allow correction of previously collected biased data. Also, pre- heating the filters for 24 h at 46° C shows significant bias reduction, with PDM pre-heated filters subsequently averaging -3.3 µg and 1400A TEOM filters averaging 5.9 µg. On a single-point comparison to gravimetric sampling, a 25.5 µg bias is only significant at low mass loadings. At 2.5 mg, this bias represents a negligible 1 % of the mass measurement. If ordinary linear regression is used, the bias is still insignificant. However, if the more valid weighted linear regression is used, it gives more weight to the smaller dependent variable values, which are more impacted by the bias. Consequently, what is 1% bias on a single high-mass value can translate into a larger bias percentage at high-mass values when performing a weighted regression on data that include a large number of low-mass values.

By R. T. C. Rasmussen

"INTRODUCTION The primary purpose of the Bureau of Mines electrolytic manganese pilot plant at Boulder City, Nev., is to improve the Bureau-invented electrowinning process and to determine the applicability of the process to the extensive domestic low-grade manganese ores with a view to making the United States dependent upon foreign sources of manganese. 3/4/ Incidental to accomplishing this purpose, the pilot plant has produced a substantive quantity of electrorytic manganese since the start of operations late in 1941; present cabacity about 1 ton a day of manganese metal. A second important purpose of the pilot plant is the supplying of electrolytic manganese for full-scale tests in cooperation with industrial users of manganese.The Rustless Iron& Steel Corp., Baltimore, Md., was the first steel company to cooperate with the Bureau of Mines in large-scale testing of electrolytic manganese. Arrangements were made with C. E. Tuttle, then president of the corporation, whereby the Bureau would supply electrolytic manganese to make a sufficient number of full-scale stainless-steel heats to demonstrate thoroughly its merits as a replacement for low-carbon ferro-manganese in the corporation's stainless-steel practice. The corporation's purpose in the investigation was to determine the possible advantages of electrolytic manganese resulting from its almost complete lack of phosphorus and caroon that might offset its then considerably higher cost per unit of manganese than low-carbon ferromanganese. The data presented herein are based upon reports of A. L. Field, technical director, and L. Weitzenkern, research engineer of Rustless Iron & Steel Corp.; they are supplemented by observation of the author who visited the plant during the tests."

Oct 1, 1945