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By D. J. Parker

Du.ring the past two years a number of oases of successful first-aid treatn . .)nt have been reported by or through the employees of the O. s. Bureau of -anes safety cars and stations. Among such cases are the following: At Benbush, w. Va., a boy or 16 years of age who ba.d just started to work in the mines was trained in first-aid by the crew of Bureau of Mines car 8. The local rr.ine superintendent afterwards reported tba.t a few dS¥s later this boy, Melvin Hollingsworht, found droming in a spring a. baby about three years old who bad wandered away fron.. har.e alone. The boy rescued the baby and perf'oxmed artificial re­suscitation upon it, thu.s saving the child's life. The Schaefer method of resuscitation bad bean ta"Ugbt the boy as a routine art of the regular first-aid course.

May 1, 1922

By G. R. Hopkins

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Jan 1, 1927

By Charles Enzian

This report is issued by the Bureau of Mines as one of a series dealing with methods of increasing safety and efficiency in mining operations. It is intended purely as a preliminary statement of the present development of hydraulic mine filling as conducted in the anthracite region of Pennsylvania. A discussion of different methods, their variations and modifications, as well as their probable extension as a result of amplified tests of the various roof-supporting materials, will be presented in a future bulletin. The history of the development of the anthracite-mining industry, from the time when the Indian tribes in the Wyoming and Lacka- wanna Valleys first discovered the existence of "stone coal," on through subsequent events-the purchase of lands containing enor- mous deposits of coal for insignificant sums of money, the develop- ment of the first mine, the formation of the first company, the build- ing of canals and railroads-up to the present time when the industry has become of such tremendous importance to the prosperity of north- eastern Pennsylvania and of the Nation itself, is intersprinkled with romance, tragedy, and pathos. The great economic lessons to be learned from a study of mining operations in the anthracite region suggest to the person interested in the efficient utilization of natural resources the need of applying such methods as will make possible the conservation to posterity of this invaluable deposit of coal that has resulted from the operation of the processes of nature during probably hundreds of millions of years. It is the opinion of many prominent mining men familiar with mining operations in the United States and abroad that under certain conditions the most practical way of preventing loss of unmined coal in pillars and of protecting surface property from damage by sub- sidence is by filling the workings with refuse material. This bulletin aims to present a general discussion of hydraulic mine filling, its origin, development, and practicability in anthracite mining.

Jan 1, 1913

By Sean Gallagher

Study Design. A split-plot experimental design was used to evaluate the influence of posture, trunk angle, and rotational velocity on peak torque output and myoelectric activity during maximal trunk extension maneuvers. Objectives. To determine whether the kneeling posture alters extension torque capabilities in isometric and isokinetic exercises as compared with standing. Also, to ascertain whether recruitment of trunk muscles is modified by such a postural change. Summary of Background Data. Factors such as workplace geometry may force workers to adopt awkward or unusual postures in the performance of manual tasks. An understanding of the limitations placed on strength in unconventional working postures is crucial to the proper design of jobs. Methods. Twenty-one healthy male subjects (mean age = 36 years 7 SD) performed 12 trunk extension exertions in standing and kneeling postures. Isometric tests were performed at 22.5°. 45°, and 67.5° of trunk flexion. isokinetic tests were done at three velocities: 30°/sec, 60°/sec, and 90°/sec. Electromyographic data were collected from eight trunk muscles to assess muscle recruitment under each condition. A prior; orthogonal contrasts were specified for analysis of both torque and electromyographic data. Results. The kneeling posture was associated with a 15% decrease in peak torque output when contrasted with standing; however, no concomitant change in trunk muscle activity was evident. Trunk hyperflexion (isometric tests) and increasing rotational velocity (isokinetic tests) were associated with reduced torque in both postures. Trunk muscle activity was primarily affected by changes in trunk angle and velocity of contraction. Conclusions. A reduced extensor capability exists in the kneeling posture, despite equivalent trunk muscle activity. The similar activation patterns in both postures suggest that the strength deficit does not result from alterations in trunk muscle function. Rather, it may be the consequence of a reduced capability to rotate the pelvis in the kneeling posture, due to a disruption of the biornechanical linkage of the leg structures. [Key words: electromyography, isokinetic, isometric, low back pain, posture. strength1 Spine 1997;22:1864-1872

By M. J. Friedel, D. E. Scott, T. J. Williams

Rock masses in deep level mines are subject to high stresses, which can result in unexpected failure of rock into mined-out openings. Historically, various independent methods have been used to discern the causes of rock bursts and to evaluate stress conditions in rock masses susceptible to violent failure. Personnel from two research centers of the former U.S. Bureau of Mines, Spokane and Twin Cities, investigated a rock burst that occurred in May of 1994 in a rock mass between the 4400 and the 4600 levels of the Sunshine Mine, Kellogg, ID. The team evaluated the current state of stress in the pillar and the most likely cause of the rock burst by studying the seismic history of the pillar, examining the geology, analyzing the available in situ stress data, calculating possible fault-plane solutions for the burst, and performing a seismic velocity tomographic survey. The results of the study showed that post-rock-burst seismicity was concentrated about 15 to 30 m west of and about 15 m above the rock-burst location. The pillar is composed of a very hard sericitic-to- vitreous quartzite of a type rarely found in the mine, but that is often found in other district mines having a history of seismic activity. In situ stress analysis of the pillar and the surrounding rock mass showed a probable stress rotation from northwest-southeast to east-west. Of four fault plane solutions, the most probable was either a left-lateral, strike-slip movement with a compressive principal stress oriented nearly north-south, or a right-lateral, strike-slip movement oriented east-west. Finally, tomographic images showed low-velocity areas (interpreted as areas of low stress) associated with the crosscuts and haulageways, and high-velocity areas (interpreted as areas of high stress) associated with the rock-burst location. High velocities were also found in a planar area oriented in an elongate northeast-southwest direction.

By Charles L. Kimbell

Bulk carriers, freighters, and tankers are the three classes of seagoing vessels engaged in transporting mineral commodities. However, vessels in these classes are not wholly devoted to mineral commodity transport, as seen in tables 16 through 22. Bulk carriers move considerable tonnages of agricultural products as well as crude minerals, their concentrates, mineral fertilizers, and the like. Freighters, owing to their great variety, can be devoted wholly to hauling mineral products or wholly to non mineral goods, as well as carrying mixed mineral commodities and non mineral commodities. They include general cargo ships, full container ships, partial container ships, roll-on/roll-off ships, and barge carriers. Tankers, although largely engaged in moving crude oil and refinery products, also transport liquid chemicals, molasses, wine, liquefied natural gas, and other fluids. Table 16 shows the distribution of the world's merchant fleet by vessel type in terms of the number of vessels, their gross tonnage, and their deadweight tonnage. The increase of nearly 1.5 % in the number of vessels between 1990 and 1991 compared with a 2.7% growth in gross tonnage and a nearly 2.3 % increase in deadweight tonnage points to an increase in the average size of vessels. Of the four categories of vessels reported, all showed increases in number and in deadweight tonnage between 1990 and 1991 except for "other," and on the gross tonnage basis, all groups registered increases. Although physical characteristics of vessels such as size, draft, crew requirements, type of propulsion system, ratio of gross tonnage to cargo tonnage, and fuel costs have undeniable influences on shipping industry performance, problems of and changes in the quantity and types of materials moved also significantly affect the shipping sector of the world economy, and thus have a bearing on the minerals sector of that aggregate. Unfortunately, comprehensive global data reflecting changes in these critical variables are not published.

Jan 1, 1993

Water infiltration control techniques are designed to reduce the total volume of water entering an underground mine, and thus, reduce the volume of mine water discharge During the development of underground mines, water may be encountered in various quantities This water must be pumped from the mine during active mining, and in many situations, the weight of water removed will be more than the total weight of mineral extracted After abandonment of the mine, infiltrating water either floods the mine workings or discharges from the mine (27, 127) Infiltrating water may enter underground mines from above, below, or laterally through adjacent rock strata Earth fractures such as faults, joints, and roof fractures resulting from surface subsidence are commonly primary causes of water entrance Into abandoned underground mines Factors affecting the quantity of water entering a mine will be the depth of the mine, location of water bearing strata, and ground water flow patterns Investigations of the quantity of water entering underground coal mines have found the average rate of infiltration to range from approximately 6,262 to 10,280 liters per hectare per day (670 to 1,100 gal/acre/day) (27) Water flowing through underground mines flushes pollutants from the mine and may result in their discharge to the environment A reduction in the amount of flow usually results in a reduction in total pollution load discharging from the mine The techniques discussed in this section can be used to reduce the volume of surface and groundwater available to enter the mine system and transport pollutants The selection of a control technique will depend upon the characteristics of the mine system and the expected cost effectiveness of the technique In order for water infiltration control to be effective in controlling mine drainage pollution, the reduction in mine water flow must not be accompanied by an increase in concentration of pollutants (127) REFERENCES 2, 27, 51, 58, 127, 132

Jan 1, 1975

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Jan 1, 2011

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Jan 1, 2011

By W. D. Mcmillan

"Magnetic surveys made by the Missouri Bureau of Geology and Mines in 931 and 1932 disclosed a large positive anomaly about a mile south of Bourbon, Mo. 3/ Electrical resistivity measurements made by the Division of Geophysical Exploration of the Bureau of Mines in the winter of 1942-43 indicated that the source of this anomaly was in the pre-Cambrian rhyolite at a depth of more than 1,400 feet. 4/In order to determine the character of the material that caused the magnetic anomaly, which might be either a body of magnetite or a large intrusive of basic rock, the Bureau of Mines drilled four holes to depths of 1,800 to 2,300 feet. Magnetite in rhyolite porphyry was encountered at 1,600 to 2,000 feet, and this is doubtless the main source of the magnetic anomaly, although it is possible that additional iron ore exists at greater depth.Hole 1 was apparently located southeast of the source of the anomaly and encountered only small stringers of magnetite. Hole 2 penetrated four mineralized zones having a total thickness of 125.7 feet and an average weighted content of 43.52 percent iron and 31.62 percent silica. These zones were tested again by a deflection hole, 2A, which gave nearly identical indications. Hole 3, 500 feet north of hole 2, penetrated 58 foot of mineralized rhyolito containing an average 43.4 percent iron.Metallurgical tests showed that the silica in the ore is tightly locked with the magnetite. After grinding to minus 100 mesh, a 66 percent iron con¬centrate with 7 percent silica was obtained by flotation."

Oct 1, 1946

The Mine Safety and Health Administration (MSHA) defines an independent contractor as any person, partnership, corporation, subsidiary of a corporation, firm, association or other organization that contracts to perform services or construction at a mine. Contractors that perform specific types of work are required to report the number of employees who work at coal mines and noncoal mines.

Jan 1, 2008

By A. J. Kraemer

This report on the physical and chemical properties of crude oils of California is one of a series on the producing districts of the United States. It includes a short discussion of results, tabulated data, and individual analyses of California crudes. Analyses of crude oils from the fields of Fresno, Kern, Los Angeles, Orange, and Ventura Counties have been published in Serials 25952 and 26083. The analyses reported in this paper corer samples that were obtained subsequent to the publication of Serials 2535 and 2608. The samples were obtained by members of the San Francisco office of the Bureau of Mines. The collecting of samples was facilitated by the courtesy of representatives of oil companies in California.

Jan 1, 1927

By S. H. Denny

"As the result of the work of an efficient safety organization, the Midwest Refining Co. at its various operations and particularly in the Salt Creek field has been able to show a definite accident reduction. Lost-time accidents during the past year have been reduced to a small number as compared with previous years, and infection cases have been almost eliminated.The accident-prevention work of the Midwest Refining Co. is in charge of the department of industrial relations, with a director as the administrative head; two safety men handle the work directly at Midwest, Wyo. A competent medical staff with a well-equipped hospital at Midwest is also an important factor in the prompt and proper treatment of injured persons when an employee is injured, he is given first-aid and then taken to the hospital with minimum delay.About 1,450 persons are employed in the 4 departments (production, gas, pipe lines, and electrical) and in the 34 districts of the Midwest Refining Co. The work at Midwest spreads over a considerable area, and new drilling operations, pipe work, and similar activities require the services of many small gangs of workers. Complete supervision, of each job, whether shall or large, is possible through the large number of superintendents, foremen, and gang pushers employed; thus, there are 20 superintendents, 78 foremen, and 115 gang pushers. The largest number of men under any one toss is approximately 15, and it is probable that much of the good safety record is due to this intensive supervision. These company officials, including the gang pushers, have been impressed with the idea that it is their duty to see that the men under them do not get hurt; the responsibility of instructing new employees in safety practices is placed directly upon them. Monthly meetings of the field officials, including superintendents, foremen, and gang pushers, and as far as possible the men, of each district are held with the safety engineer. Both officials and men are encouraged to bring up for discussion any practice or proposals looking to the changing of any conditions that will"

Apr 1, 1928

By Frederick L. Hoffman

Miners' nystagmus is the result of a peculiar form of eyestrain, which often results in impairment of vision and a consequent diminu- tion of the wage-earning capacity of the workman. Historically it has been pointed out by Shufflebotham that "This disease was first recognized by Gillett, of Sheffield, about 1854, although no case was mentioned in medical literature until 1861, when the symptoms were described by De Conde, a Belgian physician. Cases were reported by Pepp Müller as early as 1860, by Von Graefe in 1873, and by Bell Taylor, of Nottingham, and by Nieden in 1874. In this country (England) we are indebted to a very large extent to the observations and writings of the late Simeon Snell and for his pioneer work on this many-sided disease; in France Dransart occupies a similar position." In the treatise on "The Effects of Arts, Trades, and Professions," by C. Turner Thackrah, published in London in 1832, it is stated that- The complexion of the colliers, even after the removal of the dirt, is generally sallow and unhealthy. Their eyes, from the swelling of the lids, appear small, are affected with chronic inflammation and intolerant of full light. * Sickness and vomiting sometimes affect persons at their commencing the employ; and many, after a few years' trial, are obliged, by the injury which their health has sustained, and especially by the weakness of their eyes, to leave the mine. According to Greer, an authority on industrial diseases and acci- dents, miners' nystagmus occurs in 5 per cent of all miners, but it is quite probable that the reference is to European coal miners rather than to men employed in all branches of the mineral industry. According to the same authority, miners' nystagmus "is associated with a twitching of the eyelids and with considerable diminution of the range of movement of the eyes, and is particularly liable to occur in patients whose vision is subnormal owing to errors of refraction, especially astigmatism. It causes much inconvenience to those suf- fering from it and prevents them from following their usual occupa- tion as, owing to the movements of the eyes, everything at which they look appears to be in a state of perpetual motion, and in conse-

Jan 1, 1916

By P. Delogne, L. Deryck, R. Liegeois

So far as the propagation of electromagnetic waves is concerned, an underground tunnel behaves like a pipe or hollowed waveguide. Waves propagate in this tunnel with a low attenuation only if their frequency is higher than a so-called critical frequency which depends on the shape and mostly on the cross -dimensions of the tunnel and which value is in the neighbourhood of several tenths of MHz. However, when a metallic conductor is stretched along the gallery the electromagnetic characteristics of the latter are considerably modified and the effect of the cut-off frequency disappears; this is due to the fact that the gallery equipped with such a conductor works like a coaxial cable where the conductor serves as the outward conductor and the wall of the gallery as the return conductor. This is the principle of the monofilar waveguide cable which has been perfectly studied by Gabillard. Two mean characteristics of the monofilar mode are as follows: first of all, when the cable is suspended in the middle of the cross section of the gallery, the electromagnetic field occupies all the space between the wire and the walls of the gallery. When the wire is close to the wall, the electromagnetic field tends to become concentrated between the wire and the wall, with the consequence that, with the given monofilar mode power, the aerial of a receiver standing somewhere in the tunnel will capture a weaker and weaker signal. Secondly, owing to the fact that the mode of monofilar propagation uses the ground as return conductor, its power of propagation is considerably diminished; the closer the wire is to the wall the higher the attenuation, for only a very small part of the wall is utilized as return conductor. To cover great distances, everything else being equal, two or more conductors must be placed in the gallery. If the distance between two conductors of a cable is much smaller than the distance between one or other of the conductors and the walls; or again if one of the conductors surrounds the others and forms a screening, two sorts of modes appear: on the one

Jan 1, 1973

By George H. Ashley

Character The bituminous coals of Pennsylvania range from low volatile to high volatile, but are all low moisture coals The coals are of three types caking of coking, noncaking or splint, and cannel The percentage of volatile matter in all kinds changes from low at the east to high at the west This change is thought to be due to the pies sure and folding to which the coals along with the other rocks have been subjected In the Broad Top field, and in Somerset, Cambric, Clearfield, Centre, and other counties to the northeast, most coals contain from 3 to 5 times as much fixed carbon as volatile matter, the fixed carbon ranging from 67 to 75 per cent, and the volatile mattes from 16 to 24 per cent These coals are classed as lovol coals In the line of counties just west of those listed the coals are of the medium volatile class (midvols) This includes the famous Connellsville coking coal Still farther west, covering most of Washing ton and Westmoreland counties, and the counties to the north of them are high volatile coals of gas coals (hivols) This is discussed in Part I on the geology of the coals of Pennsylvania, where is given in isocaib map Cannel coals ale found in many par is of the bituminous coal field of Pennsylvania, but in particular in Beaver Butler, Armstrong, Indiana, and Clear field counties The cannels of Beaver and Butler. counties are typical high volatile cannels, many of which have been used in times past for oil distillation The cannels of Armstrong and Indiana counties are medium volatile cannels, and while main taming the physical character of cannels, have no more volatile neat ten than the coals around them The cannels of Clearfield County tie low volatile Splint coals of noncakmg coals are not abundant in Pennsylvania. The Sharon coal, formerly mined in Mercer County, was a noncaking or splint or block coal, and was formerly used in the raw state in non smelting Uses STEAM COAL Practically all of the coals of Pennsylvania are steam coals, though many coals in the Commonwealth, because of high ash, are not good steam coals The coal of the Pittsburgh district has long been famous

Jan 1, 1928

By Jeanne A. Zimmer, Charles D. Taylor, Edward D. Thimons

On a continuous miner coal face methane concentrations are affected by the quantity of fresh intake air reaching the face. When mining the box cut on a 12.2-m (40-ft) two-pass extended cut face, the continuous miner is always at the point of deepest penetration, and operation of the machine-mounted dust scrubber and water spray system improve the flow of fresh air to the end of the box cut. However, when the continuous miner leaves the box cut to begin cutting the 40-ft slab, little is known about how much ventilation air reaches the end of the box cut. The Pittsburgh Research Laboratory (PRL) of the National Institute for Occupational Safety and Health conducted a full-scale study to answer this question. Tests were run to determine how much ventilation air reaches the end of the box cut with the continuous miner at three locations in the 40-fttwo-pass extended cut mining sequence; at the end of the 40-ft box cut, at the start of the 40-ft slab cut, and 6.1 m (20 ft) into the slab cut. During these tests, methane gas was uniformly released at the end of the 40-ft box cut. Methane concentrations measured0.3 m (1 ft) from the roof and face of the box cut were used to estimate face airflow quantities. Fresh air flow rates of 1.89and 4.72 m/sec (4,000 and 10.000 cfm), scrubber flow rates of 0, 4,000 and 10,000 cfm, water spray pressures of 0 and3827 kPa (0 and 120 psi), and a blowing curtain setback position of 15.2m (50 ft) were used during these tests. To improve ventilation to the end of the 40-ft box cut when the continuous miner was starting the 40-ft slab cut and 20 ft into the slab cut, the blowing curtain was advanced from its 50-ft setback to locations 40-ft and then 8.5 m (28 ft) from the face. KEYWORDS: Face ventilation, Extended cut, Methane, Box cut, Continuous miner, Scrubber

By Ronald D. Hill, Elmore C. Grim

Coal-haul and mine access roads are defined as any road constructed, improved or used by the operator (except public roads) that ends at the pit or bench. These roads constitute approximately 10% of the total area directly disturbed by the surface mining operation(l). In some cases, the land disturbed by haul roads exceeds the area included in the mining operation. Studies (2 and 3) of the U. S. Forest Service in eastern Kentucky show that typical contour mining roads exhibit poor alignment, excessive grades, insufficient strength and durability, and poor drainage. Mine roads in other Appalachian- States, particularly where contour mining is practiced, appear much the same as those in Kentucky. Access roads(4) were also found to be a large source of sediment. It is possible that of the sediment that finds its way into the streams as much (or even more) originates from the haul roads as from the mining operation. Most roads are built as cheaply as possible, and good road-building design and practice are ignored. Maintenance schedules are generally inadequate, and upon completion of mining, haul roads are usually abandoned, with little or no attempt made to bed them down(5 ) . Such roads deteriorate very rapidly (Figure 68). Area mining, which is practiced in flat to gently rolling terrain, presents fewer haul road related environmental problems. These roads through necessity are generally well engineered because of the heavy equipment using them, such as 240 ton (217 metric ton) haul trucks. They must have wide beds, good alignment, and adequate drainage to permit coal haulers to run at top speed during all seasons of the year. Excessive dust can be a public nuisance and a driving hazard, and it is hard on equipment. Calcium chloride and sodium chloride have proven to be effective materials for controlling dust. Two applications during the summer when the ground surface is moist at the rate of 1/2 pound per square yard (.26 kilograms per square meter) (3 1 have been suggested. Th4 most common procedure is to keep the roads wet by using water trucks. Sediment that reaches the streams can be traced to one or more of the following five basic phases of haul-road life:

Jan 1, 1974

By G. E. McElroy

"while investigating the presence of heavy strata gases* in certain mines of the East Tintic mining district of Utah, a small, local body of light, very hot gas of high-nitrogen composition was noted in one of the mines. Observations and analyses indicate that this light gas was resulting from very rapid oxidation of finely disseminated pyrite, in lead-silver sulphide ore. The gas was actually mine air which had lost a large proportion of its oxygen content by reaction with the pyrite. This body of gas was hanging in a local high spot about 5 by 5 by 5 feet in size, caused by caving, at the end of a crosscut. Fifty feet from this spot, an air current of 6000 cubic feet per minute was entering the 5 by 7 foot cross-cat from a raise from below.On account of the vapor contained in the gas, the bottom level of the gas could be plainly seen and was practically a horizontal plane, but of slightly wavy appearance, coinciding with the point where an acetylene light was extinguished. This body of gas was visited on three occasions and samples obtained by means of evacaated bulbs and by water displacement. The temperature of the gas was ap¬proximately 175 degrees P. on all three occasions, so that sampling required thick gloves and quick action. Air three feet below the vapor line had a temperature of only 120 degrees F., and a relative humidity of 27 per cent. The stratification of the air and gas mixtures was so sharply defined that the sampler could hold his head a few inches below the vapor level for an appreciable period of time without any noticeable effect other than that due to the high temperature. At one foot below vapor level, it was 135 degrees F., and the relative humidity was 30 per cent. When a candle and an acetylene light were raised into the gas from below, the candle flame was extinguished at a point two inches lower than the acetylene flume, indicating a drop in oxygen content from about 16 per cent to 12 per cent (oxygen content of normal dry air 20.05 per cent) in the distance of two inches."

Sep 1, 1921

By Andrew B. Cecala, Edward D. Thimons

"The Bureau of Mines has recorded a number of different background dust sources that significantly contaminated the air breathed by bag machine operators. These background sources, observed at five different plants over the past 2 years, can expose bag machine operators to more significant dust concentrations than the filling process itself. To keep bag operator exposure within acceptable dust levels established by the Mine Safety and Health Administration, U.S. Department of Labor, the significance of these background sources must be realized, and the sources must be identified and controlled. The purpose of this work is to identify common background dust sources and show the significant effects that they have on the bag operator's overall dust exposure. INTRODUCTIONThe purpose of this report is to identify some common background dust sources in and around the bag-filling area. Although these background dust sources are of ten unrecognized, they can be more significant sources of contamination than the dust generated from the bagging process.The bagging of mineral products into 50- and 100-lb paper bags is common throughout the entire mineral processing industry. Bagging is performed by a bag operator who sits in front of a two- or four-station fill machine. The bagger's function is to attach empty bags to the fill nozzles as filled bags are ejected from the machine. If the product being bagged is extremely fine (smaller than 200 mesh), the bag operator's dust exposure is usually one of the highest in the plant.The bag operator is exposed to two primary dust sources. The first is product blowback during the bag-filling cycle. This occurs as excess pressure is released from around the fill nozzle during filling. As the excess air forces its way out of the bag, product is forced out with it. This blowback of product leaving the bag creates a considerable amount of dust. The second major source is the ""rooster tail"" of product thrown from the bag valve and fill nozzle as the bag is ejected from the fill machine. Since the bag is pressurized as it leaves the machine, product spews out of the valve for a few seconds."

Jan 1, 1986