Search Documents

By Oliver Bowles

The United States Bureau of Mines has within its ranks a group of engi- neers who are engaged in working out quarry problems, the solution of which will be of general benefit to the industries involved. The problems undertaken are approached in a systematic and thorough manner, all the evidence for and against any proposed change or new development being collected as carefully as an attor- ney would prepare his data on an important case. Unlike the attorney, however, the Bureau engineer does not take sides; his judgment is based entirely and in- partially on the array of facts presented. In order to gain the desired infor- mation he visits many plants, consults with the leaders in the industry, works out experiments in his laboratory, and supplements this information with a stu- dy of all available literature already published on the subject in any part of the world. As an engineer who has for eight years conducted such inquiries in the stone industry, I propose to discuss the Bureau of Mines viewpoint; and it may be of interest to consider with me in a brief and general way the engineer's method of looking at quarry problems, and some of the results attained through past and present labors. While the Bureau has conducted no investigation directly for the crushed- st one industries, two years of investigative work at cement-plant quarries, and work now being conducted at lire-plant quarries, has a very direct bearing on the problems of the crushed-stone industry, since stripping, drilling, blasting, loading, and transportation are similar in many respects in all stone quarries. The results of cement-plant quarry investigations are to be found in Bureau of Mines Bulletin #160. (b) Two short papers on lime-plant quarry problems have been issued in mimeographed form as Serial #01 (c) and Serial 3 (d).

Jan 1, 1923

By E. S. Longfellow, S. H. Katz

Poisonous hydrocyanic acid gas (HCN) is sometimes evolved in dangerous quantities from cyanides used in metallurgical and chemical operations. This gas is much used for fumigating buildings, ships, greenhouses, and such commodities as grain and cotton to destroy rats, mice and insect pests. Wherever cyanide fumes are evolved, thorough ventilation is necessary in order to render the sur- rounding air safe to breathe. Many persons have been killed by entering tanks and fumigated places too soon, and a simple test for this gas would promote safety. In view of the need for an easy method for quantitatively determining HCN in air, the three color reactions used originally for testing HCN in solution tions *** were modified and adapted. The reactions employ (1) picric acid (CH(NO2)3OH) which is yellow but combines with hydrogen cyanide to form a red- purple dye, isopurpuric acid****; (2) phenolphthalin (CH1604), which is a reduc- tian product of the phenolphthalein (CH4) used for acid indicator, this colorless substance is oxidized***** by presence of HCN to pink colored phenolph- thalin; and (3) guaiacum which oxidized from colorless to blue******. Phenolph- thalin and guaiacum require the presence of copper compounds which catalize the color formation by reduction of cupric cyanide. The chemical processes involved *Associate physical organic chemist, Bureau of Mines, Department of the Interior. **Assistant gas chemist, Bureau of Mines, Department of the Interior. 2014 20 *** Kohn-Abrest, E., Notice toxicologique sur les gas: Arnales des Falsifica- tions, vol. 8, 1915, pp. 215-35. (Tested air with picric acid and guaiacum papers). **** Élasiwietz, H., Ueber eine neue Zersetzungsweise der Trinitrophenylsaure: Anal. der Chemie, vol. 110, 1859, pp. 289-303. ***** Weehuizen, F., Phenolphthalin as reagent for HCN: Pharmaceutrisch weekblad, Utrecht, vol. 42, 1905, pp. 271-2. Abstract, Jour. Chem. Soc., vol. 88, part 2, 1905, p. 489. ****** Schonbein, C. F., Ueber den thatigen Zustand der Helfte des in dem Kupfer- oxydenthaltenen Sauerstoffs und ein darauf beruhendes hochst empfindliches Reagens auf die Blausaure und die loslichen Cyanmetalle: Jour. fur. Praktische Chemie, vol. 106, 1869, pp. 263-70.

Jun 1, 1923

By W. P. Yant, R. R. Sayers

The rather sudden increase in the use of methanol as an antifreeze for automobile radiators has caused considerable comment , with some anxiety to persons interested in industrial and public health , regarding the possible health hazard in dispensing and using the product . In view of this , the chemical industry interested in the manufacture and marketing of methanol requested the Bureau of Mines to make an impartial and extensive investigation of the hazard involved . With the assistance of the industry this investigation is now in progress and will extend throughout the present winter . When these observations are finished a complete report will be made . At present , however , the acute interest in the problem and the many inquiries that have been received from manufacturers of methanol , garage owners , the automotive industry , public health officials , and private persons demands a brief statement relative to the reasons for the recent availability of methanol for antifreeze purposes , the plan of the bureau's investigation , and the trend of the results of the investigation obtained to date .

Dec 1, 1930

By Brian G. White

The Coeur d'Alene Mining District of northern Idaho is remarkable for its number of large ore bodies and for the amount of its historical production of lead, zinc and silver (Fig. 1). Since veins were first discovered in 1884, more than 127 Mt (140 million st) of ore have been produced from narrow, high-grade veins. Mining continues at the Lucky Friday, Galena and Sunshine mines (Fig. 2). All have been in production for decades. At these mines, more efficient mining and exploration techniques have reduced costs while adding significant new reserves. Even the old Bunker Hill Mine, where ore was first found in 1875, continues operation on a limited basis, partly involving production of world-class pyromorphite specimens. Until recently, the Coeur Mine was also a profitable silver producer. Other large producers have included the Star-Morning, Hecla, Page, Standard-Mammoth, Hercules and Gold Hunter mines (Fig. 2). The first deposits were discovered by prospectors who spilled over from the Murray gold mining district, 24 km (15 miles) to the north. The Bunker Hill Mine was founded the year after the first veins were discovered. Bunker Hill has now operated for more than 100 years. Production includes 2.3 Mt (2.6 million st) of lead, 1.1 Mt (1.2 million st) of zinc and 4.1 kt (132 million oz) of silver. Total district production through 1996 (Springer, 1997) amounted to 7.3 Mt (8.1 million st) of lead, 3 Mt (3.3 million st) of zinc, and 34.5 kt (1.109 billion oz) of silver. This record establishes the district as the largest recorded producer of silver in the world, while also yielding major quantities of lead and zinc. Only Potosi, Bolivia, may have produced more silver, although records are unclear. Despite the district's longevity, historic production and current activity, the published literature on the district lags behind with regard to recent concepts of district geology. The most recent comprehensive US Geological Survey (USGS) bulletins (Hobbs et al., 1965; Fryklund, 1964) are dated. Much research in the last half century has been short-lived or geographically restricted because the district is large and its geology is complex - and even this research tends to remain unpublished. Thus, it has been difficult for in- [ ]

By E. W. Dean

In the early winter of 1919 the Pittsburgh petroleum laboratory of the Bureau of Mines undertook the work of testing fuel oil samples representing purchases of the United State Shipping Board for ships sailing from the port of New York. fuel oil was, at this time, being bought on a contract which involved specifications issued by the United States Navy under dace of October 2, 1920 (See Bulletin 1, Oil Division, U. S. Fuel Administration.)The object of the Bureau of Mines in undertaking this inspection work was twofold. (1) The Bureau was in position to give, and the Shipping Board needed, reliable laboratory service for checking the quality of the fuel oil purchased, the value of which ran into millions of dollars for,year's supply. (2) It was believed, and later demonstrated, that the existing specifications did not insure the obtaining of a reliably satisfactory quality of oil.The objection to the specifications concerned the employment of a clause limiting the gravity of the oil. The inadequacy of gravity specifications for several types of petroleum products has long been recognized, and there was every reason to reason to believe that they were no more desirable for fuel oil than for gasoline, kerosene, or lubricating oil. A first and obvious objection was the fact that it is somewhat difficult to make accurate gravity tests on ""heavy"" residuum fuel oils. (The Bureau found it necessary to employ or such tests a rather tedious procedure involving the use of a picnometer and an accurate balance, as the simpler methods, employing hydrometer or displacement balance, proved unreliable in a large proportion of cases.) A second and more important objection was that gravity tests, even when accurately made, do not provide a reliable index of the actual quality of the oil.

Feb 1, 1921

By Charles L. Kimbell

Comprehensive world mineral industry investment data do not exist, but limited material published on aggregates of in vestment in some elements of the world mineral industry suggest a continued up-turn in the investment level, at least in market economy countries in 1989. Steel industry investments in Organization for Economic Cooperation and Development (OECD) countries are not yet available for 1989 but, as shown in table 6, increased by 22.1% in 1988, after showing a decrease of 5.2% (revised) in 1987. The pattern of investment ups and downs varied during 1988 within country blocs and economic alliances showing no particular trends. Investment in the steel industry by the United States increased by 58.3% between 1987 and 1988 and was 1 1.9% higher than the previous highest amount invested during the 1984-88 period but was still 41.5% less than the amount invested in 1983. Investment in the steel industries of the European Coal and Steel Community (ECSC) dropped again in 1988 from the revised amount for 1987, which became the first drop after several years of steady growth in what became the expanded ECSC in 1986. This drop in 1988 was the result of lower investments by Denmark, France, the Federal Republic of Germany, Ireland, Italy, Luxembourg, the Nether- lands, and Spain, investments grew or remained level in Belgium, Portugal, and the United Kingdom in 1987 and 1988. A decrease in investment in the Canadian (-26.6%) steel industry was offset by in- creases registered by the members of the European Free Trade Association (EFTA) of 31.7%, by Japan of 19.8% by Turkey of 22.4%, and a slight increase by the nations of Latin America. If data for the world steel industry as a whole, including those of the centrally planned economy countries, were available, the same pattern presumably would be shown as that reported; that is, it would remain fairly stable, with increases in some countries being offset by decreases in others. However, the lack of comprehensive information on the centrally planned economy countries makes it impossible to determine whether the overall trend was up or down despite recorded increases or decreases in production of the materials involved. Preliminary data show that investment levels in industries dealing with the production and/ or processing of mineral commodities for

Jan 1, 1992

By John H. Soulé

"INTRODUCTION The property of the Silver Spot Mines Co. is in the Boston Hill area within and adjacent to the southwest corner of Silver City, N. Mex. The area was visited by Bureau of Mines engineers 3/ in 1941 and 1942 during the investigation of possible sources of manganese. The area was visited again in November 1944 4/ to study the possibilities of geophysical exploration of the manganiferous-iron deposits. This geophysical work was performed in 1945 5/, confirmed the existence of known deposits of manganiferous-iron ores, and indicated the probable extent and situation of others.The Silver Spot property was churn-drilled from 1926 to 1929 during exploration for manganiferous-iron ores. The sludges from a number of the holes indicated low-grade lead-zinc mineralization. Lead and zinc minerals also were found on the dumps of some of the old shafts when the property was visited by D. H. Mullen, an engineer of the Bureau of Mines late in 1946. A diamond-drilling project was proposed. It was started in April 1947 with the intention of investigating the best of the known ore indications as shown by the old churn-drill holes and thus gathering new data upon which to base future work. Only one hole was drilled before the project was terminated because of lack of funds and time."

Mar 1, 1948

By J. D. Noll

The Mine Safety and Health Administration (MSHA) has promulgated rules to limit the exposure of metal/nonmetal underground miners to diesel particulate matter (DPM). These rules have resulted in many types of control tech­nologies being implemented including diesel particulate filters (DPF). The passive type DPF is the most desirable because it requires little maintenance and it regenerates while the vehicle is operating. One problem with passive DPFs is that many vehicles cannot develop the sustained exhaust temperatures needed to initiate DPF regeneration, and thus it is required that the DPF be catalyzed to decrease the temperature needed for regeneration. In some past studies, such catalyzed filters have been shown to cause an increase in the nitrogen dioxide concentrations in the exhaust, resulting in a potential health hazard. In this study, a lightly catalyzed DPF along with a fuel-born catalyst were employed to help reduce the DPM emissions from a 980F loader used for cleanup in a stone mine. After 30 days of use, the filter continued to regenerate successfully at the exhaust temperatures generated by this loader, substantially reduced DPM concentrations emitted in the exhaust, and did not cause a measurable increase in nitrogen dioxide levels that could be attributed to the device.

Jan 1, 2009

By R. M. Winslow

"The phosphorus content of an iron ore is a determining factor as regards the value of the ore and also its metallurgical treatment. If some method of treatment, such as concentration, leaching, etc., could be used and the phosphorus con- tent of the ore reduced, it would be an important advancement in the iron mining industry towards the utilization of high phosphorus ores. Large bodies of material toe high in phosphorus to be marketable under present conditions would be made available, and a great deal of ore from the Cuyuna Range and other places, which is relatively high in phosphorus but otherwise suitable for making spiegel, could be reduced in phosphorus content sufficiently to permit its use in furnaces producing speigel.The form in which phosphorus occurs in iron ore is a much disputed question and it probably varies with the type and location of the ore. The statement has been made that ore piles on long exposure to the atmosphere often decrease in their phosphorus content. (Emmons, S.F. - Ore deposits, 1913, p. 652; Leith, C.K., Mesabi iron bearing district, U.S.G.S. Monograph 43, 1903, p. 275) There is described below experiments on the leaching of iron ores high in phosphorus, to determine whether it was economically possible to reduce the phosphorus content appreciably by leaching. As the research had a practical as well as a theoretical application, only low concentration of acids and alkalies were used.A number of variables were tried, among these being: (1) The solvent used, (2) strength of the solvent, (3) volume of solution used, (4) time ore was agitated (5) type of ore, and (6) screen size of the ore. The amount of ore taken was kept constant."

Jul 1, 1921

By J. F. Barkley

During the present war emergency, under the urge of the Federal Government to store coal, the following; questions are arising n the minds of coal users: (a) Will the coal lose any of its heating value in storage? (b) Will it slack and give a smaller-size coal? (c) Will its burning characteristics change in any way? (d) Will it catch fire from spontaneous combustion? (e) What precautions should be taken when storing coal? In regard to the loss of heating value of coal in storage, tests made by the Bureau of Mines show that the loss commonly has been overestimated. Various types of storage tests were made on New River, Pocahontas, Pittsburgh Gas, and Sheridan Wyoming coals. The following is quoted from Bureau of Mines Bulletin 136, Deterioration in the Heating; Value of Coal During Storage, by H. C. Porter and F. K. Ovitz:

Jan 1, 1942

By Industrial Research Office

"The U.S. Bureau of Mines established on August 15, 1983, the Generic Mineral Technology Center for Respirable Dust within the Mining and Mineral Resources Research Institutes (MRIs) at The Pennsylvania State University and West Virginia University in association with participating MRIs at Massachusetts Institute of Technology and the University of Minnesota. The Center's research program has been developed with recognition of the stated objective of the Federal Mine Safety and Health laws which is to ""... permit each miner the opportunity to work underground during the period of his entire adult working life without incurring any disability from pneumoconiosis or any other occupation-related disease . . . ."" The Center's program is designed to permit an accelerated attack on the fundamental research problems for the control of respirable dust in mines.The primary goal of the Center is to reduce the incidence and severity of respirable dust disease through advancing the fundamental understanding of all aspects of respirable dust associated with mining and milling and the interaction of dust and lungs. The Generic Technology Center's research program explores these concerns with the objective of refining existing strategies and developing new respirable dust control techniques that are consistent with the fundamental dust-lung interaction processes that lead to mine worker disability. The work concentrates on: (1) control of dust generation; (2) dilution, dispersion and collection in mine airways; (3) characterization of dust particles; (4) interaction of dust and lungs; and (5) relationship of mine environment, geology, and seam characteristics to dust generation and mobility. The fundamental aspects of this work are applicable to the control of respirable dust problems in both hard rock mines and coal mines and to other dusts such as diesel-generated. The Center activities involve the training of engineers and scientists, graduate students and undergraduate students through their respective institutions, and the technology transfer to the industry. The Center also serves as the reference center for publications' in the respirable dust area.The Center is composed of faculty from the four universities/institutes listed above. The personnel, facilities and equipment that are available to the Center from these entities are diverse, complementary and comprehensive. More than fifty scientists, engineers; and medical personnel in the Center are engaged in respirable dust research. Additionally, the expertise and facilities of the NIOSH--Division of Respirable Disease Studies are available as a result of the existing relationship between NIOSH and West Virginia University.The breakdown of the dust research program into the five areas mentioned above recognizes the importance of an integrated fundamental research approach to the respirable dust problem compatible and complementary with the existing and ongoing U.S. Bureau of Mines activities. The specific projects in the research areas are a result of a careful evaluation of the past and ongoing research activities, the identification of areas where data and information are scarce, and awareness of the recommendation of the National Academy of Sciences Study on the Measurement and Control of Respirable Dust. Penn State is the administrative unit for the Center. Funding to date is nearly $6.5 million."

Aug 31, 1989

By S. A. Matthes

This Bureau of Mines report describes a system for the dissolution of metal and mineral samples using a microwave heat source. Samples and an acid mixture are placed in sealed polycarbonate vessels. The vessel contents are heated using microwaves, digested for 2 min, and quickly cooled. After the solution is brought to a final volume, the vessel contents are heated an additional 2 min in the microwave oven. Using this method, a slag, a feldspar, and a Ni-Cu alloy were dissolved and analyzed by atomic absorption spectroscopy. Values obtained for Na, K, Cu, Ni, Si, Mg, Mn, Ca, Al, and Fe agreed with certified values and had an average relative standard deviation of 1 pct. This system results in a significant savings in time and expense over traditional methods of sample dissolution, and is ideal for preparing solutions for analysis by atomic absorption, plasma optical emission, or X-ray spectroscopy.

Jan 1, 1983

By McHenry Mosier

The Anson Bette manganese mine, with two prominent manganese-bearing outcrops in schist, has attracted considerable attention for its variety of manganese minerals and its possibilities as a potential source of manganese. Little mining was done prior to 1925, when the present owner acquired the property, and operations since that date have been intermittent. Mine workings are open cuts with a maximum depth of 35 feet. The two outcropping ore deposits are irregular, pipelike bodies about 500 feet apart. As nothing was known of the grade or extent of mineralization in depth, four holes totaling 1,072.5 feet of bore Were diamond-drilled by the Bureau of Mines in the summer of 1943, with the results shown in figures 3 to 6. In.1945 a geophysical survey was run to map the magnetic anomalies in the manganese-bearing belt as a means of determining the locations of manganese deposits. Positive correlation of magnetite and manganese ore was not obtained.

Jan 1, 1949

By Samuel B. Flagg

The Bureau of Mines is endeavoring to ascertain how mineral fuels in which the Government has a direct interest, by ownership or use, can be utilized with highest efficiency. For this reason the bureau has been, and is, carrying on investigations to ascertain the condi- tions of furnace construction and management that are necessary to insure the smokeless combustion of the different coals that are found in public lands or are purchased for Government ships and power plants. Another reason for the bureau undertaking these investigations is the need of better furnace management and a more careful selec- tion of fuel at many Government plants. There are Federal build- ings in hundreds of cities. The coals available at many of these cities differ greatly in quality, and the furnaces in some of the Fed- eral buildings were not designed for efficient utilization of the cheap- est available coal. Hence, some of the boiler plants smoke badly unless fed with low-volatile coal and have caused repeated com- plaints not only from neighboring property owners who have suffered damage, but from persons endeavoring to create a civic pride in clear air. In the course of its fuel investigations the bureau has noted the conditions governing fuel consumption in different cities and has studied the attempts made by these cities to abate smoke through the passage of ordinances imposing penalties on smoky stacks. Some results of that study are presented in this report. The most im- portant conclusion reached is that smoke abatement by ordinance can not hope to succeed unless supported by public sentiment and that a smoke ordinance should look to future prevention rather than to immediate prohibition. In other words, strict control of furnace construction offers much greater hope for smoke abatement than desultory imposition of severe penalties on the escape of "dense" or "black" smoke.

Jan 1, 1912

By W. M. Weigel

"Sand is one of the commonest materials for industrial use, not only as a building material, but in many industrial processes. The general name applies to all grades, from the comparatively impure, unsorted product used in concrete, to especially sized products of extreme chemical purity. Various definitions have been proposed, all more or less open to objection, as they fail to cover special applications. One is: ""Sand - The fine granular material naturally or artificially produced by the disintegration or crushing of rock or slag"". This does not fit the definition of sand as understood by geologists, who consider sand only as a naturally formed product. Another is: ""Sand - The fine granular material naturally produced by the disintegration of rock"". This does not take the chemical com-position into account, and for practically all uses, except in concrete and plaster products, a material composed predominantly of silica or rather quarts is implied.Sand for special purposes usually requires different methods of preparation from those where the ordinary mixture of sizes as naturally occurring are suitable. One of the classes requiring the most uniformly sized grains is sand blast sand.Sand Blast SandThe use of the sand blast has increased rapidly during the past few years. It was formerly used almost entirely in the foundry to clean and remove inequalities from rough castings. This is still the most important application, but in addition, it is now employed for the removal of paint from old surfaces, carving and engraving on stone and marble, glass cutting, cleaning or renovating the rails of stone and brick buildings that have become discolored, preparing the surface of metals for the electrolytic bath, putting the final finish to metal surfaces, and has even been proposed as a means of channeling or cutting out blocks of stone in the quarry."

Jun 1, 1924

By L. B. Pankratz

Thermodynamic data on the sulfides were reviewed, evaluated, and compiled at the Bureau of Mines Albany Research Center. Values for Cp°, S°, H°298 -(G° - H°298)/T, ?Hf°, ?Gf°, and log Kf are given in tabular form. Cp°, H° - H°298, ?Hf°, and ?Gf° are also expressed algebraically.

Jan 1, 1987

By D. T. Couillard

Video technology is becoming an important tool for many designers of industrial training programs. This report describes how trainers at the Minntac Mine, Mt. Iron, MN, have developed videocassettes of safe job procedures (SJP's) for training miners assigned to perform unfamiliar work tasks. All steps necessary for videocassette production, from idea to finished product, as well as the required equipment and prices, are listed and/or briefly explained. Minntac officials believe that the SJP videocassettes have contributed significantly to a reduction in mine accidents.

Jan 1, 1985

By W. E. Wallace, V. Castranova, P. Hathaway, F. H. Y. Green, E. D. Recad, V. Vallyathan, M. J. Keane

Inhaled particle contact with pulmonary surfactant in the hypophase lining pulmonary alveoli was modeled in vitro by exposing two respirable sized dusts, kaolin and silica quartz, to lecithin, a major component of pulmonary surfactant, emulsified in physiologic saline. Lecithin adsorbs to the dusts upon incubation at 37º C and suppresses their cytotoxicity as measured by pulmonary macrophage and erythrocyte assays, suggesting that pulmonary surfactant provides a defense system against prompt cell membrane lysis by inhaled dusts. Subsequent pulmonary macrophage phagocytosis and lysosomal enzyme digestion of the coated dusts was modeled in vitro by incubation with phospholipase A2 for one hour. With increasing lipase activity, silica hemolytic potential was restored to native silica levels. Kaolin was retoxified to levels far in excess of native kaolin hemolytic potential. Elution, thin layer chromatography and phosphate assay of treated dusts indicate most lecithin on silica is digested to lysolecithin and desorbed, silica retoxification being due to surface and adherent lysolecithin effects. Most lecithin on kaolin is not digested in this same time; that which is results in adherent lysolecithin which is responsible for the kaolin retoxification. Digestion with phospholipases A2 and C together produces only weakly retoxified kaolin. Results suggest that surface adsorption properties which control the adherence of prophylactic surfactant distinguish the pathogenic potentials of quartz, kaolin and mixed dust.

Jun 1, 1988

"The U.S. Bureau of Mines established on August 15, 1983, The Generic Mineral Technology Center for Respirable Dust (Dust Center) within the Mining and Mineral Resource Research Institutes (MRIs) at The Pennsylvania State University and West Virginia University, and in association with participating MRIs at Massachusetts Institute of Technology and the University of Minnesota. In 1986, Michigan Technological University (MTU) was awarded a grant through the Dust Center. The center's research program has been developed with recognition of the stated objective of the Federal Mine Safety and Health law, which is ""... (to) permit each miner the opportunity to work underground during the period of his entire adult working life without incurring any disability from pneumoconiosis of any other occupation-related diseases..."" The Dust Center's program is designed to foster an accelerated attack through fundamental research on problems confronting the control of respirable dust in mines. The interactions of the universities and the research program components in the characterization of coal seams, respirable dust particles and the workers lungs are depicted in the logo of the Dust Center.The primary goal of the Dust Center is to reduce the incidence and severity of respirable dust disease through advancing fundamental understanding of all aspects of respirable dust associated with mining and milling, and the interaction of dust and lungs. The Dust Center's research program explores these concerns with the objective of refining existing strategies and developing new respirable dust control techniques that are consistent with the fundamental dust-lung interaction processes that lead to mine worker disability. The work concentrates on: (1) control of dust generation; (2) dilution, dispersion and collection of dust in mine airways; (3) characterization of dust particles; (4) interaction of dust and lungs; and (5) the relationship of the mine environment, geology, and seam characteristics to dust generation and mobility. The fundamental aspects of this work are applicable to the control of respirable dust problems in both hard rock mines and coal mines, and to other dusts such as those generated by diesel equipment. Achieving the Dust Center's goals also involves the training of engineers and scientists, graduate students, and undergraduate students through their respective institutions, and technology transfer to industry. The distribution of personnel in the various universities are presented in Table 1. A directory of Dust Center principal investigators is presented in Appendix 1. A summary of degrees granted and mineral sector employment is presented in Table 2. The subjects of theses developed under the various research projects are presented separately in Volume 7. The center research is fully compatible and complementary with the existing and ongoing U.S. Bureau of Mines activities (see Volume 2). Additionally, the expertise and facilities of the NIOSH--Division of Respirable Disease studies are available as a result of the existing relationship between NIOSH and West Virginia University. Figure 1, Respirable Dust Center Projects and Activities, presents the various projects in the five major areas of investigation and the scope of characterized dust samples, the suite of tests, the sampling and dust generation methods, and the size, chemical and mineralogical analysis performed in the center. Table 3 presents a summary distribution of the 95 publications and presentations that have emanated from the center. In addition there are more than thirty presentations made at each annual Dust Center review meeting. The titles, authors and location of presentation for publications supported by the Dust Center are presented in separate publication volumes for 1984 (Volume 3), 1985 (Volume 4), 1986 (Volume 5) and 1987 (Volume 6)."

Jan 1, 1988

By E. D. Regad, W. E. Wallace, V. Vallythan, V. Castranova, P. Hathaway, F. H. Y. Green, M. J. Keane

"Abstract—Inhaled particle contact with pulmonary surfactant in the hypophase lining pulmonary alveoli was modelled in vitro by exposing two respirable sized dusts, kaolin and silica quartz, to lecithin, a major component of pulmonary surfactant, emulsified in physiological saline. Lecithin adsorbs to the dusts upon incubation at 3TC and suppresses their cytotoxicity as measured by pulmonary macrophage and erythrocyte assays, suggesting that pulmonary surfactant provides a defence system against prompt cell membrane lysis by inhaled dusts. Subsequent pulmonary macrophage phagocytosis and lysosomal enzyme digestion of the coated dusts was modelled in vitro by incubation with phospholipase A2 for one hour. With increasing lipase activity, silica haemolytic potential was restored to native silica levels. Kaolin was retoxified to levels far in excess of native kaolin haemolytic potential. Elution, thin layer chromatography and phosphate assay of treated dusts indicate that most lecithin on silica is digested to lysolecithin and desorbed, silica retoxification being due to surface and adherent lysolecithin effects. Most lecithin on kaolin is not digested in the same time; that which is. results in adherent lysolecithin which is responsible for the kaolin retoxification. Digestion with phospholipases A2 and C together produces only weakly retoxified kaolin. Results suggest that surface adsorption properties which control the adherence of prophylactic surfactant distinguish the pathogenic potentials of quartz, kaolin and mixed dust.INTRODUCTIONERYTHROCYTE HAEMOLYSIS and pulmonary macrophage enzyme release assays show quantitatively comparable high cytotoxicities for both silica quartz and kaolin respirable sized dusts (BROWN, et al., 1980; DANIEL and LE BOUFFANT, 1980.) This contrasts with the strong potential for respirable quartz dust to induce pulmonary fibrosis and the much more limited potential of kaolin dust to do the same (MORGAN and SEATON, 1975).In an attempt to understand this anomalous situation, assays were performed on quartz and kaolin dusts incubated with dipalmitoyl lecithin emulsified in physiological saline, to simulate the initial contact of a respired dust with the pulmonary alveolar hypophase. The ability of kaolin dust to adsorb dipalmitoyl lecithin from physiological saline has been quantified (WALLACE, et al., 1975). Such lecithin treatment suppresses the cytotoxicity of both silica and kaolin to background levels (WALLACE, et a1.,1984).Surfactant coated detoxified dusts should then be phagocytised by pulmonary macrophages, incorporated into a macrophage secondary lysosome and exposed to hydrolytic lysosomal enzymes. Among these is phospholipase A2, which hydrolyses diacyl lecithin to lysolecithin. This was modelled by incubating lecithin treated dusts with phospholipase A2 in vitro to determine if the enzyme can digest the dust-adsorbed lecithin, and if the retoxification differs between the two dusts in a manner which might distinguish their pathogenicity."

Jan 1, 1988