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By H. S. Chiang, Y. Luo, S. S. Peng

"IntroductionThe way in which the particle sizes distribute in the airborne coal dust plays an important role in the transportation of the dust in the mine air and human respiratory systems. Though the particles of a size less than 10 microns could be inhaled, the real distractive portion of the dust is that the sizes range from 1 to 5 microns since only they can reach the lungs and be retained there. Those with an equivalent diameter larger than 5 microns will settle on the membranes of the branchial tubes(1) while those with diameter less than 1 micron can either be exhaled out of the lungs or the settled quantity is so insignificant that does very little harm to the lungs. In the transportation process, the finer dust will fly farther away from the sources than the coarser ones. Thus once the fine dust is generated and becomes airborne, it will spread out to a larger area.In this paper, the coal samples collected from two longwall faces were analyzed statistically for size distribu¬tion. A mathematical model is proposed and the effects of different conditions on the dust size distribution were analyzed using the mathematical model.Sampling and Statistical AnalysesSampling Instrument and ProcedureThe instrument used in the sampling were Mine Safety Appliance (MSA) personal sampling units equipped with 10-mm nylon cyclones, pre-weighed MSA PVC filters and constant-flow pumps.Two longwall operating faces were selected for the dust sampling. The two faces were located in two coal mines ex-tracting Pittsburgh seam. The double-ended ranging-drum shearer applying the unidirectional cutting sequence was employed. The two-leg shield supports were used for face support. The width of the two faces was about 215 meters.In each of the two faces, four sampling stations were set up. The stations were located at the cross-cut immediately outby the headentry side, the 15th support (25 m), 65th support (107 m) and 111th support (182 m) from headentry T-junction, and numbered as #1, #2, #3, and #4 station, respectively (Figure 1). At each sampling station, a group of three sampling units was hung at proper position. At cross¬cut (#1) station, the units were hung about one foot under the roofline in the center of the cut (Figure 2a), and at the stations in the face, the units were position near the hydraulic legs and one foot below the support canopy (Figure 2b).One complete set of 12 samples was collected for each day. The sampling were performed for five consecutive days. All the samplings were conducted in the morning shifts. The time duration of the sampling for each day was about five hours. During that time, the shearer might complete 5 to 7 mining cycles."

Mar 1, 1989

By A. F. Baker

Laboratory flotation of synthetic coal-pyrite mixtures and high-pyritic-sulfur coal indicated that ferric chloride (FeCl3), aluminum chloride (AIC13), chromium chloride (CrCl3), and cupric sulfate (CuSO4) are potential pyrite depressants. For each metal salt there appeared to be a range of pH values and optimum concentration for selectively depressing pyrite in coal flotation. Pyrite was depressed in the pH range from 4.5 to 7.0 with ferric chloride, from 5.8 to 7.0 with aluminum chloride, from 6.4 to 7.1 with chromium chloride, and from 6.4 to 7.4 with cupric sulfate. Best separation of pyrite from coal was achieved in flotation solutions containing from 2 X 10-5 to 5 x 10-5 mole/ liter of each salt. In solutions containing excess salt concentrations, coal was also depressed. These Bureau of Mines tests demonstrated on a laboratory scale that, in solutions containing 4 X 10-5 mole/liter ferric chloride and from 1 x 10-4 to 2 x 10-4 mole/liter sodium hydroxide, the pyritic sulfur content of a Lower Freeport bed coal sample could be reduced from about 2.51 percent to less than 0.60 percent with recoveries of over 83 percent. The depression of pyrite appears to be due to the adsorption of positively charged colloidal metal hydroxide at the pyrite-solution interface. This hypothesis is supported by zeta potential determinations which showed that suspended coal and pyrite particles in solutions containing metal salts are positively charged in the pH range where depression occurs.

Jan 1, 1971

Data released by the Commerce Department's Bureau of Economic Analysis show continued gradual change in the real GNP's rate of growth in 1984, which has eased from an annual growth rate of 10.1 percent in the first quarter lo 7.1 percent in the second quarter, and then to 2.7 percent in the third quarter. The automobile industry strike in the last half of September had only a small effect, estimated at less than a 0.1 percentage point reduction in the growth rate. Among the components that comprise the GNP, personal consumption and fixed investment grew at lower real rates in the third quarter than in the second quarter, while net exports decreased. Personal consumption expenditures increased $0.4 billion in the third quarter, compared with an increase of $20.1 billion in the second quarter. Nonresidential fixed investment increased $3.9 billion in the third quarter, compared with $9.6 billion in the second quarter. The other component of fixed investment--residential investment--increased from $60.8 billion in the second quarter to $61.2 billion in the third quarter. Real net exports of goods and services decreased $1 1.3 billion in the third quarter, compared with a $3.1 billion decrease in the second quarter. Although exports increased from an annual rate of $144.7 billion to $150.2 billion, imports increased much more, from an annual rate of $1 56.2. billion to $172.8 billion (table 1).

Jan 1, 1984

By James F. Devine

The radial, vertical, and transverse components of particle velocity were recorded by Bureau of Mines investigators along gage arrays extending in one or two directions for 145 to 3,170 feet at five quarries. Of the 39 quarry blasts, 12 were instantaneous blasts, 5 were of the one hole per delay type, using millisecond delayed caps, and 22 were multiple hole per delay type employing millisecond delay detonating fuse connectors. Charge weight per hole ranged from 8 to 1,500 pounds, and the charge weight per delay interval, including the instantaneous blasts, ranged from 25 to 4,620 pounds.

Jan 1, 1966

By Ann G. Kim

Fires that occur in abandoned coal mines, waste banks, and in coal outcrops constitute a serious health, safety, and environmental hazard. Toxic fumes, the deterioration of air quality, and subsidence constitute the greatest hazards from these fires. Although tires on abandoned mined land (AML) occur in every coal-producing state, the severity of the problem varies. Methods to extinguish or control AML fires, including excavation, fire barriers, and sealing, are generally expensive and have a relatively low probability of success This U.S. Bureau of Mines report includes information from a variety of sources, i.e., agencies of the Federal Government, State agencies, research reports, conference proceedings, product information, and technical literature. This information has been collated into a comprehensive discussion of AML fire problems. Data on past fire control projects and on the estimated extent of the current problem have been compiled. Factors affecting the occurrence, propagation, and extinguishment of AML fires are discussed. Conventional fire control methods are described, and their probable effectiveness is evaluated. Information on the hazards of AML fires and safety considerations is included. The status of current technology, recent improvements in fire control methods, and areas of current research are discussed.

Jan 1, 1993

By W. C. McLaughlin

Under a cooperative agreement, the Bureau of Mines, Magma Copper Co., and ASARCO, Inc., tested backfilled ground support systems at t.wo elevations in Magma's San Manuel, AZ, mine. The tests were mainly for guidance in designing the loading crosscuts of the new ASARCO Sacaton underground mine. Two-piece, wide-flange steel sets for 8-by 8-ft (2.44-by 2.44-m) and 11-by II-ft (3.36-by 3.36-m) openings were designed. Set spacing was 3 ft (0.91 m) and 5 ft (1.52 m), respectively. After erection, the sets were lagged with various test materials. The void between the lining and the ground was backfilled with sand and pea gravel. Instruments measuring strain (used to determine changes in stress) were placed beneath the sets and in the backfill. Results indicate the backfilled sets in the smaller drift (2315 grizzly level, panels 6 and 7) of 8-by 8-ft (2.44-by 2.44-m) cross section are a viable permanent support system, lower in cost than the standard formed concrete. Results are inconclusive in 2615 grizzly level, panels 5 and 6, where wide-flange steel sets were used with 5-ft (1.52-m) long concrete gob lagging of T-design.

Jan 1, 1983

By L. F. Heising

The Bureau of Mines evaluated 191 composites from the central Mesabi Range, Minn., chiefly by reductive roasting and magnetic separation. After reductive roasting and magnetic separation at minus 325 mesh, 28 composites produced concentrates that contained an average of 66.0 percent iron with less than 10 percent silica. Recovery of contained iron was over 90 percent. Natural magnetic material in excess of 5 percent was present in 142 composites. Trial flotation tests were used to evaluate three samples unresponsive to reductive roasting and magnetic separation procedures, and satisfactory concentrates having low silica contents (averaging 6.6 percent) were achieved.

Jan 1, 1965

By J. P. Dunford

This U.S. Bureau of Mines report describes the development of a yielding steel post for underground mine support. The report covers concept development, laboratory tests, modifications, and field evaluations. The objective of this work was to develop a stiff support member capable both of supporting high loads and yielding when excessive amounts of mine entry closure were present. The 6-to 7-ft steel post was designed to yield nearly 2 ft while maintaining a 45-ton (force) load. The post is a three-piece unit consisting of top and bottom telescoping legs and a separate foot bracket. It develops its load-carrying characteristics when the lower pipe, with an attached interference ring, is forced into the larger top pipe. Laboratory tests were used to determine critical loads and post performance for various post lengths. Field tests showed that the posts could perform in actual mining conditions. The post has the ability to provide support in highly yielding ground and also, because of its slender profile, enhance ventilation and provide more area for travelways and escapeways. The design is simple enough to allow for fabrication at most mine shop facilities.

Jan 1, 1989

By R. H. Sprute

The Federal Bureau of Mines conducted full-scale field tests in electro-kinetic dewatering and consolidation of slimes in cooperation with the Hecla Mining Co. at two of the firm's underground mines in north Idaho. To test the technique on new deposits, 4,000 ft3 of slimes from a collection sump, pumped into a watertight stope equipped with electrodes, were treated in two steps. Immediately after placement, direct current was applied using a floating electrode to hasten settlement of suspended fine particles. After removal of clarified water, the residue was further dewatered and hardened with electrokinetic treatment. In 25 hours, the material had become firm and dense with a surface capable of supporting workmen. In testing old deposits, 10,000 ft3 of slimes, placed in an unused tail drift 10 to 12 months previously, were treated. This material was sufficiently consolidated by electrokinetics to allow its removal from the mine with standard ore-handling equipment. In both tests, electrokinetic treatment densified slimes in a relatively short time with moderate power consumption.

Jan 1, 1976

By Ben E. Lindsly

The study of "bottom-hole samples follows in natural sequence the study of samples obtained under high pressures at the well heads of flowing wells. The principal object of this phase of gas-solubility research, started actively in January, 1930, was to gain a more accurate knowledge of the physical and chemical characteristics of the oil-gas mixtures that exist in natural reservoirs.. In possession of actual data regarding the condition of the oil; the quantity of gas liberated from solution upon dimunition of pressure; and the relative volumetric proportions of gas to oil at various pressures throughout the flow string in a well, it should be possible to predict, with a fair degree of accuracy, That physical changes these mixtures would undergo throughout the life of a pool. Such information not only is important in designing flow strings in flowing Tells but is important also in solving problems relating to pumping efficiency and the power required for pumping. Although certain fundamental data were obtained in the study of samples taken at the well head, "bottom-hole" samples are more representative of subsurface mixtures of oil and gas because they are obtained at reservoir temperatures, and before the oil has had the opportunity of intermingling with extraneous gas; that is, gas which either was not in solution originally, or which was liberated from solution at higher pressure, and later became mixed with the original undissolved gas.

Jan 1, 1933

By H. J. Heinen

To maximize productivity through improved minerals processing technology, the U.S. Department of the Interior, Bureau of Mines, is investigating particle agglomeration techniques as a means of increasing the percolation rates of leach solutions in heap leaching of clayey gold-silver ores. Simulated heap leach experiments were conducted on 50-pound charges of ore that were contained in 5.5-inch-diameter columns, 5 feet in height. Results indicated that the percolation rate of cyanide leach solution could be enhanced markedly by mixing the ore with controlled amounts of lime, flocculants, and water, and then aging the mixture prior to the column leach step. Experimental results obtained on 20-mesh silver tailings and gold ore crushed to 3/8 inch and to 1 inch showed that it was possible to increase percolation rates as much as 100-fold without sacrificing silver-gold extraction. Larger scale tests conducted in 24-inch-diameter, 16-foot-high columns closely paralleled bench-scale results. By improving percolation leaching, these techniques have the potential of helping to solve environmental problems associated with tailings disposal as well as making an important economic impact on gold-silver recovery operations. Investigations are continuing to develop binders superior to lime for particle agglomeration pretreatment.

Jan 1, 1979

By Árpád B. Palotás, Adel F. Sarofim, John B. Vander Sande, Lenore Rainey Christian, J. Feldermann

"Interest in the fine structure of soots and carbon blacks is motivated by a variety of possible applications. The structure provides information on the origins of the particles and on their adsorptive and reactive properties. This paper describes a method for quantification of the structure of soots and carbon blacks based on direct electron microscopic observation followed by image analysis of these materials. High-resolution transmission electron microscopy (HRTEM) provides a very detailed observation of particle structure. The differences in soot structure, because of its complexity, may not be easily quantifiable with the human eye; therefore, high-level computer software has been used to manipulate HRTEM images. This technique involves the application of fast Fourier transforms (FFT) to single particles and the measurement of characteristic parameters such as interplanar spacings and crystallite sizes from these particles. The methodology and application of this characterization technique are presented here. Results are shown for dif¬ferent samples obtained from soot and carbon black particles selected to illustrate the capabilities of the methodology. Quantitative information can be obtained on structural characteristics, e.g., interplanar spacing, circularity, orientation, elongation, and length distribution of lattice fringes, as well as on the fractional coverage of the extracted pattern. c 1996 Wiley-Liss, Inc.This paper presents a combination of techniques for recognizing and classifying different carbonaceous materials, using their structural morphology. A new method to assess and quantify the parameters which define such structures is proposed and discussed. The technique is based on the use of HRTEM (high-resolution transmission electron microscopy) and computational image analysis.It is well-known that carbonaceous materials like graphite, soots, coals, cokes, chars, etc. possess characteristic structural appearances which can vary from mostly random or amorphous to a perfectly ordered graphitic crystalline structure (Buseck and Bo-Jun, 1985; Buseck et al., 1987). The carbon structure has been variously described as turbostratic (Oberlin, 1989) or as crumpled sheets (Rouzaud et al., 1991) to indicate that parallel layering, reminiscent of graphite, is observed over dimensions of nanometers, but that these planes or crystallites show disorder over larger scales. The degree of order of such structures is strongly dependent on the thermal treatment of the material as well as on the composition of the source of the carbonaceous material. The value of the electron microscope in studying the morphology of such materials has been well-established, and abundant information is available (Ishiguro et al., 1991; Lahaye and Prado, 1978; Buseck, 1992).The use of HRTEM has brought further insight into this matter. Qualitative assessment of the structural order of such materials has been attempted over a long period of time in order to differentiate between various sources or treatments. There is, to date, no successful method available for quantifying the structural characteristics of various carbonaceous materials. This paper presents a technique which is able to recognize dif-ferent materials and to quantify the structural parameters of those materials using HRTEM and computational image analysis, including pattern recognition techniques.In the case of perfectly ordered graphitic crystals, electron diffraction is widely used for obtaining details on structure. Analysis of diffraction patterns can reveal parameters such as interplanar spacing, d002, crystallite size along the c-axis, Lc, crystal size in the plane of the layers, L., mean number of crystallites, Nc, etc.Complicated electron microscopy methods such as defocusing, tilted illumination, axial illumination, etc., often have to be used in order to characterize complex materials such as randomly oriented crystals in soots and carbons. Obtaining the right fo"

Jan 1, 1998

By W. T. Millar

"INTRODUCTION The purpose of the Star Lake project was to investigate, by geophysical surveying and diamond drilling, the magnetite deposits in the northwestern Adirondacks, the ultimate objective being to increase iron production in eastern United States,ACKNOWLEDGMENTSIn its program of investigating mineral deposits, the Bureau of Mines has as its primary objective the more effective utilization of our mineral resources to the end that they make the greatest possible contribution to the national security and economy. It is the policy of the Bureau to publish the facts developed by each project as soon as practicable after its conclu-sion. The Mining Branch, Lowell B. ""Moon, chief; conducts preliminary examinations, performs the actual investigative work, aid prepares the final report. The Metallurgical Branch, Oliver C. Ralston, chief, analyzes samples and performs beneficiation tests.The chemical and spectrographic analyses included in this report were performed at the Eastern Experiment Station of the Bureau of Lines at College Park, Md., under the general supervision of J. B. Zadra, chief, College Park Division, Metallurgical Branch, and under the immediate direction of Dr. Alton. Gobriel in charge of the laboratory service unit.The mineral exploration was under the general supervision successively of John D. Bardill, district engineer, and McHenry Mosier, chief, College Park Division, Mining Branch. The work was done under the immediate supervision successively of J. P. Ryan, N. A. Eilertsen, and W. T. Millar, project engineers."

Sep 1, 1947

By Charles Will Wright

This paper has been written to aid the owner of a small gold mine or prospect in preparing a report on his property for the purpose of interesting capital. If an owner can afford to do so, he should employ a mining engineer of recognized standing and experience to examine and report on his property, but many owners of small -mines and particularly of prospects cannot make the expenditure required for this. Further, many of them do not know how to prepare a description which will cover those features of a deposit on which a potential investor promises his opinion as to its worth. If such an owner is convinced that he possesses an orebody of sufficient grade and size to warrant the required expenditure for a thorough investigation and wishes to present his property to prospective investors, then the following suggestions concerning the proper way to sample his deposit, estimate the tonnage of developed and probable ore, and prepare a report may be of assistance.

Jan 1, 1933

By G. L. Oldright, Virgil Miller

"This paper is the eighth; of a series on smelting in the lead blast furnace, and the third' of a group on the modifications brought about by the introduction of rich charges.ACKN0WLEDGMENTSThe data that appear in these articles were obtained through the courtesy of the operators of the Bunker Hill smelter at Kellogg, Idaho. The authors take this opportunity to express their appreciation to Stanley A. Easton, the vice-president and general manager, Frank M. Smith, smelter director, and to A. F. Beasley, the smelter superintendent, and his staff.INTR0DUCTI0NIt has been noted that the gases issuing from the top6 of the charges in the International Smelting Co.'s furnaces at Tooele, Utah, were very similar in composition to the gases from the top of the iron blast furnace, as they contained about 26 per cent of CO and 12 per cent of C02, the rest of the constituents being mainly nitrogen with a very little hydrogen and oxygen. It has been seen that where the column of coke was sufficiently high, the production of C0 gas to carry out the reduction of lead ores was accomplished in about the same manner as in a gas producer. In some cases, there was a little oxygen in the ""top gas"" -- usually not over a few tenths of a per cent, but at times amounting to several per cent. The presence of this gas was attributed to irregularities in operation that permitted air to come up through the tuybres to the surface without meeting any coke that was incandescent. Only a hundredth of a per cent or so of sulphurous oxides was present in the gases issuing from the top of the furnace."

Apr 1, 1931

By M. C. Malamphy

A general description of the activities and results of bauxite investigation by the Bureau of Mines at its bauxite project in Saline and Pulaski Counties, Ark., has been given in Report of Investigations 4251. The factual data obtained during the project are reported in a series of Reports of Investigations, of which this is the seventh. The data are accompanied by maps showing the location of holes drilled and the deposits developed. Each area upon which work was done is reported by half townships. Each bauxite deposit investigated was assigned a name and a number for ready reference and identification, and its location and name are shown on the appropriate half-township map. The description of each half township is followed by a description of each deposit developed in that half township. The 14 half-township maps and 77 detail maps of the bauxite deposits in , this series of reports give the locations and numbers of all the holes drilled on the project, except the deep holes drilled to test the geophysical anomalies. The locations of those holes are shown on figure 13 in volume 1. The descriptions of the deposits developed are followed by complete detailed logs of the drill holes. Many of the widely spaced exploratory holes did not discover bauxite of .1 minable thickness and grade. The pertinent information obtained from the widely spaced exploratory drill holes has been summarized and tabulated, and a table for each half township is given with the discussion covering that area.

Jan 1, 1948

By Oliver Bowles

In its geologic sense the term marble is applied to rocks consisting of crystallized grains of calcite or dolomite or a mixture of the two. Although limestone has the same chemical composition as marble it differs in that the component particles of calcium or magnesium car- bonates are granular and noncrystalline. In marble the crystals may be intimately intergrown, whereas limestone is an aggregation of unrelated particles cemented together into a solid mass. In its commercial sense the term marble has a much wider applica- tion. As susceptibility to polish is one of its chief commercial assets, all calcareous rocks capable of polish are classed as marbles. Lime- stones that show little crystalline structure may, if they take a good polish, be classed as marbles. Furthermore, serpentine rocks, even if they contain little calcium or magnesium carbonate, are classed as marbles, as they are commercial substitutes of true marbles.

Jan 1, 1916

By L. J. E. Hofer

This Bureau of Mines study, part of a broad program of research in air pollution related to minerals, was conducted to determine the nature and extent of the poisoning of catalysts when used to remove certain air pollutants from exhaust gases. The poisoning examined in this investigation occurs when leaded gasoline is used as a fuel for automotive engines. This research was conducted in cooperation with the Public Health Service. The smog in the Los Angeles area is attributed to the effect of radiant energy on the mixture of hydrocarbons and nitrogen oxides found in the atmosphere there. A large portion of the hydrocarbons is believed to originate in the exhaust gases of automobiles. To prevent the escape of these hydrocarbons into the atmosphere catalytic mufflers have been proposed. In principle, these are simple and nonmechanical, consisting of a vessel charged with a catalyst capable of destroying the exhaust hydrocarbons by catalyzing their oxidation. However, these catalysts are severely affected by the particulate matter, mainly in the form of lead sulfate (PbS04), lead oxysulfate (PbS04.Pb0), and Lead chlorobromide (Pb(Cl,Br)2), contained in the exhaust gas. Deposition of lead on the catalyst as PbS04, PbS04, PbS0, and Pb(Cl,Br)2 restricts catalytic activity. As a result,after 20,000 miles of operation the temperature necessary to achieve 50-percent conversion of isopentane in a mixture of 0.2 percent isopentane, 2 percent carbon monoxide and 4 percent oxygen, and the balance nitrogen at 10,000 hourly space velocity has risen from 400° C. to 500° C. even with a catalyst taken from the exit portion of the catalyst bed. The rest of the catalyst was more severely affected. Therefore, it would appear that operation for 20,000 miles is near the limit for a catalyst.

Jan 1, 1963

By N. S. Dalal, V. Castranova, X. Shi, W. Wrr, V. Vallyathan

"SUMMARY Data presented here indicate that freshly fractured silica exhibits surface characteristics and biologic reactivity distinct from aged silica, and on this basis we propose that these surface features may lead to enhanced manifestations of lung Injury. Grinding of silica produces ~10"" Si and SI-O (silicon-based) radicals per gram of dust on the particulate surface which are characterized by an electron spin resonance (ESR) spectrum centered around g = 2.0015. These silicon-based radicals react with aqueous media to produce OH radicals, which are demonstrable using a DMPO spin trap. The concentration of silicon-based radicals in silica decreases with aging in air and exhibits a half-life of ~30 h, whereas its ability to generate OH radicals in aqueous solution decreases with a half-life of ~20 h. However, on storage in aqueous media, the concentration of silicon-based radicals end the dust's ability to generate OH radicals decrease significantly within a few minutes. Freshly ground silica is also more biologically reactive than aged silica, because freshly crushed silica activates a greater respiratory burst In alveolar macrophages than aged silica, i.e., storage of ground dust in air decreases silica-Induced superoxide anion secretion, hydrogen peroxide release, and NBT reduction by 25%, 68%, and 43%, respectively. Furthermore, compared to aged silica, freshly ground silica exhibits a greater cytotoxic effect on cellular membrane Integrity, i.e., a 1.5-fold increase in LDH release from macrophages, a 36-fold increase in hemolytic activity, and a three-fold increase in the ability to induce lipid peroxidation. Because acute silicosis is frequently associated with occupations in which freshly fractured crystalline silica of respirable size is generated, the present study suggests that fracture-generated silicon-based radicals may play a significant role in the pathogenesis of this disease. AM REV RESPIR DIS 1955; 133:1213-1218IntroductionOccupational exposure to crystalline silica can be associated with either chronic or acute pulmonary disease. Chronic silicosis becomes manifest 20 to 40 years after first exposure and is characterized by development of concentric hyalinized nodular lesions in the lung with the de-velopment of dyspnea over a period of several decades. Acute silicosis, on the other hand, is manifested by a rapid on-set after exposure and is characterized by the accumulation of an amorphous granular lipoprotein exudate in the airspaces and rapid development of respiratory disability within a few years (1-3).Information is growing concerning the etiology of chronic silicosis. Studies sug-gest that several mechanisms may be in-volved in the development of fibrosis. Lung injury may result from silica-induced release of lysosomal enzymes from alveolar macrophages (4, 5). In ad-dition, silica-induced activation of su-peroxide anion and hydrogen peroxide release from alveolar macrophages may result in oxidant-induced damage to lung parenchyma (6). Silica exposure can also result in the release of mediators from alveolar macrophages which enhance the proliferation of fibroblasts and the syn-thesis of collagen by these pneumocytes (7, 8)."

Jan 1, 1988

By Laurence G. Britton

Accurate flammability and ignitability data for chemicals form the cornerstone of procedures used to assess the hazards associated with commercial chemical production and use. Since 1967 the ASTM E27 Committee on the Hazard Potential of Chemicals has issued numerous, widely used consensus standards dealing with diverse testing and predictive procedures used to obtain relevant chemical hazard properties. The decision to issue a standard rests solely with the membership, which consists of representatives from industry, testing laboratories, consulting firms, government, academia, and instrument suppliers. Consequently, the procedures are automatically relevant, timely, and widely applicable. The purpose of this paper is to highlight some of the widely used standards, complemented with hypothetical but relevant examples describing the testing strategy, interpretation, and application of the results. A further goal of this paper is to encourage participation in the consensus standards development process. The paper is published in two parts. The first part (in the preceding issue of Process Safety Progress) dealt with the E27 standards pertaining to thermodynamics, thermal stability, and chemical compatibility. The second part, published here, focuses on the flammability, ignitability, and explosibility of fuel and air mixtures. © 2005 American Institute of Chemical Engineers Process Saf Prog 24: 12?28, 2005

Jan 1, 2005