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By C. H. Herty

[Ferromanganese continues to be in indispensable requirement in steel manufacture. Approximately 470,000 tons of the 80 per cent ferro-alloy was consumed in 1929 and increasing amounts will be required annually by the steel industry unless some satisfactory substitute is found. An average of 14 pounds of metallic manganese is for each ton or steel produced, The principal use of manganese is for deoxidation of the metal in the steel refining processes, although a considerable amount r s also used for the production of special manganese steels. Unfortunately, domestic production of manganese ore is inadequate to meet normal peace-time requirements, not to mention increased abnormal war-time demands.]

Jan 1, 1930

By T. H. Dubaniewicz, J. E. Chilton

Fiber-optic technology is progressing rapidly, including the development of fiber-optic sensors for many applications. These sensors have the advantages of high sensitivity, light weight, small size, high bandwidth, and freedom from electromagnetic influences. The U.S. Bureau of Mines is investigating the use of fiber-optic technology to monitor mine atmospheres. This report describes a methane monitor based on differential absorption of infrared light. The monitor can detect methane concentrations as low as 0.2 vol pct as far away as 2 km via fiber-optic cable. The upper range is 100 vol pct methane. Since the system requires no electrical power within the mine, it is intrinsically safe.

Jan 1, 1992

By W. D. Bryson

This paper is one of a series being prepared by the United States Bureau of Mines on tunnel-driving methods. The practices described are those used at No. 11 mine of the Colony Coal Co., Denver, Colo. No. 11 Mine is situated at Dines, some 14 miles north of Rook Springs, in Sweetwater County, Wyo. It is served by a spur off the Winton branch of the Union Pacific Railroad. The Colony Coal Co.'s mines were opened in 1918, and since that time have been among the largest producers of coal for the railroad and domestic markets in the Rock Springs coal district.

Jan 1, 1932

By McHenry Moiser

"SUMMARY This mine, which was discovered in 1846, was active in the 1850's, in the 1870's, and again in 1883. Since this last date, it has been idle. Two parallel bed-veins in lower Silurian limestone, about 50 feet apart, strike N. 70° E. and dip 70° NW. The north vein had an average width of 12 feet to a depth of 50 feet, where it was barren. The south vein had an average width of 16 feet to a depth of 75 feet; on the 110-foot level, although well-defined it carried little or no values. The zinc content of the ore was as high as 12 percent, and some lead and silver were associated with it. A reduction plant for production of spelter and zinc oxide was constructed at the mine. The only available record of production is for 1873 to 1876, inclusive, when 357 tons of smelter was shipped. The mine is caved and inaccessible, and nothing now remains of the treatment plant.Four holes totaling 1,046 feet wore diamond-drilled to probe for extensions of the ore in depth. Core recovery was about 85 percent. No samples were taken for analysis.INTRODUCTION AND ACKNOWLEDGMENTSIn its program of investigation of mineral deposits, the Bureau of Mines has as its primary objective more effective utilization of our mineral resources to the end that they make the greatest possible contribution to national security and economy. The policy of the Bureau is to publish the facts devel¬oped by each project as soon as practicable after its conclusion. The Mining Branch, Lowell B. Moon, chief, conducts preliminary examinations, does the actual investigative work, and prepares the final report. The Metallurgical Branch, Oliver C. Ralston, chief, analyzes samples and makes beneficiation tests.The deposit was examined in 1944 by C. B. White, mining engineer of the Bureau of Minos. Diamond-drilling was under the immediate supervision of McHenry Mosier. 2/ The diamond-drill cores were logged by Arnold Brokaw, geologist, Federal Geological Survey, and 'wore filed in the core library of the Bureau of Mines, Mount Weather, Va."

Jun 1, 1948

By Maria I. De Rosa

This report analyzes mine fires for all U.S. underground and surface coal mining categories by state and 2-year time periods during 1990-1999. Risk rate values are derived, and ignition source, methods of fire detection and suppression, and other variables are examined. The data were derived from Mine Safety and Health Administration (MSHA) mine fire accident publications and verbal communications with mine personnel. The analysis will provide the National Institute for Occupational Safety and Health, MSHA, and the mining industry with a better understanding of the causes and hazards associated with mine fires and will form a basis for future fire research programs.

Jan 1, 2004

By R. Larry Grayson, Douglas F. Scott

Data on health-related illnesses and disease in the mining industry are scarce, and information on rates and costs is not readily available. Substantial amounts of research are being directed to addressing these issues, including work at the National Institute for Occupational Safety and Health’s (NIOSH) mining health and safety laboratories in Spokane and Pitts-burgh. This paper briefly discusses the current status of some miner health-related issues, including those involving coal dust, silica dust, diesel particulate matter, asbestos, noise, lead, welding fumes, and skin disorders, as well as research and other activities aimed at protecting miners from occupational illnesses and disease.

By T. F. Dumm, O. Trass, V. R. Koka, L. G. Austin

"The size distributions of carefully screened 2 size fractions of ground materials were determined using a Microtrac laser dif-fractometer. The size distributions were fitted to the empirical function P(x) = 1/[1 + (x50/x)1] where P(x) is cumulative mass fraction less than Microtrac size, x. The standard deviation of A for a 50 second test time was approximately 0.5, so that seventeen test times give a mean with an estimated error within t 0.25 (95% confidence level). Values of were 5.44, 4.82, 4.40 for a coal ground under different conditions, indicating statistically different shape distributions; the average value for mica was 2.91 owing to the high aspect ratio of the particles. The ratio of x50 to the geometric mean sieve size was 1.2 for the coal and 0.70 for mica.1 IntroductionKoka and Trass have presented evidence [1,2] that materials ground in the Szego mill [3] give different shapes depending on the milling conditions. The variations in shape were deduced qualitatively by viewing SEM photomicrographs of selected 1/2 screen fractions. This paper quantifies their observed differences in shape by using measurements of the size distributions of screen fractions examined in a laser diffractometer [4] (Microtrac, Model 7991). The basic concept is that particles of 'a given ""screen"" size will give a wider distribution of ""Microtrac"" size when the particles are flaky with high aspect ratios, and a narrower distribution when the particles approach the cubical and spherical geometries.2 TheoryAustin and Shah [5] have shown that coal screened within a 1. 1/2 upper-to-lower sieve size range will give rise to a much wider distribution of Microtrac size. They found that the screen interval of irregular fragments of comminuted coals or quartz gave Microtrac size distributions which could be described by the simple function"

Jan 1, 1988

By S. P. Kinney, A. C. Fieldner, S. H. Katz

"The regrettable death of James S. Cunningham, Foreman Miner, attached to Bureau of Mines Rescue Car No. 2, while wearing a half-hour type oxygen breathing apparatus in a gasoline storage tank at Trinidad, Colorado, raised the question as to the possibility of gasoline vapors permeating the rubberized fabric of the breathing bags of such apparatus.It is known that most gases and especially certain organic vapors permeate rubber, by solution or a similar process. The rubber becomes saturated with the gas and if a concentration of gas is maintained on one side of the rubber sheet it slowly gives off gas from the other side. It of course takes some time for the gas to diffuse through the rubber and the length of time before it reaches the other side is proportional to the thickness of the rubber. The amount of gas that passes through per unit of area in unit time increases with the concentration of gas and also varies with the structure and composition of the rubber.It has been suggested that the gasoline vapor could not have penetrated into the interior of an oxygen breathing bag because the pressure is greater on the inside, but this is not true as the process of permeation by solution in the rub¬ber is affected only by the difference in the partial pressures of gasoline vapor on the inside and outside of the bag. The positive oxygen pressure on the inside can only prevent the entrance of gasoline vapor through measurable holes, and has no effect on permeation by diffusion through the rubber.A sample of gasoline was obtained from the tank in which Cunningham met his death. Examination by Dr. E. W. Dean of the Petroleum Division of the Bureau of Mines gave the following results.This shows the gasoline to be heavy and typical of the gasolines sold throughout Colorado for motor fuel A. Salvus half hour oxygen apparatus was arranged with the breathing bag only in a gas tight box in which the space was kept saturated with the vapor of this gasoline. The main part of the apparatus was outside the box. Oxygen from the apparatus was breathed by a man in the usual manner. Gas samples were taken from the box at intervals to determine the concentration of gasoline vapor, also samples of the oxygen breathed were taken from a side tube in the mouthpiece. The room temperature was 75°F. The concentration of gasoline vapor in the box at the beginning of the test was 4.3%. The man breathing from the apparatus thought he detected gasoline in his oxygen in two minutes after starting the test. Analysis of the inspired oxygen at this time showed 0.03% gasoline vapor. The same man remained on the apparatus for 18 1/2 minutes without suffering any ill effects. His place vas then taken by another man who wore the apparatus until the oxygen was exhausted without noticing more than a trace of gasoline at any time. At the end of the test the inspired oxygen contained 0.07% gasoline vapor. The total time of test was 38 minutes."

Dec 1, 1919

By Wilbert J. Huff

For the past 8 years the technical studies conducted by. the Explo- sives Division of this Bureau have been summarized in a series of annual reports.3 This report deals with activities from July 1, 1942, to June 30; 1943. Specific problems have been in immediate charge of section or unit leaders, to whom credit is given.

Feb 1, 1944

By L. B. Berger

In this investigation, the ampoule type of carbon-monoxide (CO) detector which is manufactured under license of U. S. Patent 1,644,014 (October 4, 1927) was tested for sensitivity and reliability. This detector was devised primarily for examining the air of manholes and sewers for possible dangerous contamination with CO before workman enter those places, but dine to the simplicity of the device it may have a more general usage for examination of atmospheres which are known or suspected to be contaminated with CO. Some of the suggested uses are the examination of the air in garages, tunnels, mines, around blast furnaces, gas plants, and in the home.

Jan 1, 1930

By Philip W. Holland

This U.S. Bureau of Mines (USBM) report describes a chromatographic method that is used for rapid field determinations of carbon dioxide in natural gas streams at a USBM helium production facility. The method employs a commercially available portable gas chromatograph that is equipped with a 10-m fused-silica capillary column coated with a porous polymer. The instrument operating parameters permit determinations to be performed over a concentration range of 10 ppm to 10 pct with a frequency of 20 samples/h. The speed at which determinations can be performed is an important factor when evaluating efficiency or troubleshooting processes at the helium facility.

Jan 1, 1994

By Gary L. Mowrey, William D. Monaghan, George F. Persetic, Gregory M. Molinda

Ground penetrating radar (GPR) has been investigated by the U.S. Bureau of Mines Pittsburgh Research Center for its potential to determine rod hazards in underground mines. GPR surveys were conducted at four field sites with accompanying ground truth to determine the value of GPR for roof hazard detection. The resolution of the current systems allows detection of gross roof fractures (>6A mm (>0.25 in) zone) or rider beds in coal measure roof. Data quality is not yet sufficient to detect small bed separations or subtle lithologics changes in the roof. Differences in data quality are discussed, as well as suggestion for collecting improved data.

Jan 1, 1996

By James E. Bell

Quartz crystals occur on a farm in the vicinity of Laurel Fork, Carroll County, Va., in abundance over a large area, This has been known for several years, but no work had been clone, up to the Bureau of Mines examination in 1943, to determine the amount of crystalline quartz of usable quality. Field exploration was undertaken throughout the month of June 1943.

Jan 1, 1950

By S. P. Kinney

[The blast-furnace operator is often confronted with the problem of determining the size of the materials which are used in the furnace burden. The statement is heard that the coke is larger or smaller or that certain ore is finer than that previously used. A screen analysis of the materials used gives a measure of the different sizes of materials in an aggregate. When one is fine and the other is coarse, the difference is obvious; but when the materials are of similar sire, it is more difficult to estimate the degree of finances or coarseness. In considering raw materials it would be desirable to be able to judge the size of the radio ideal materials entering the furnace and the burden as a whole, by one representative value, such as the average size of particle. Previous work by Perrott and Kinney3 developed a method for measuring the average size of particle in a mass of finely ground materials, and an attempt will be made to apply this method to the materials included in the blast-furnace charge and to the entire burden.]

Jan 1, 1930

By C. O. Hawk

As an exploratory effort to produce useful products from coal by a new path, the Bureau has made a few experiments on the fast heating of finely ground coal particles by irradiation with a flash of high intensity light. The flash was produced by an electrical discharge at high voltage through a xenon-filled tube. The flashes lasted from 2 to 3 milliseconds. The reaction took place in small sample tubes, ½ inch-dimeter by 4 inches long, and with small amounts of coal (total amount charged 0.1 gram, probable effective amount not more than 20 milligrams). Average particle size of the coal, estimated on a numerical basis, was 20 microns. Temperatures reached were evidently quite high, because all products obtained in quantity were characteristic of high temperature pyrolysis. Apparently, conversion of the coal was extensive where isolated particles received the full benefit of a flash. It seems particularly significant that acetylene was present in appreciable amounts--comprising almost 3 percent of the total gaseous product in one case. This is good evidence of a short heating period to very high temperature (well above 1,000° C) followed by rapid quenching. Although the results are interesting, they do not suggest any immediate practical application.

Jan 1, 1963

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

A kinetic model was developed to describe the production of superoxide (02) by single pulmonary alveolar macrophages (PAM). Model predictions were compared to experimental results obtained from single rat PAM. The O2 - was quantified by measuring the reduction of nitroblue tetrazolium (NBT) to a diformazan precipitate (NBTH2) from video-recorded images of individual cells. The kinetic model considered three reactions: (1) the production of extracellular 0 - from the reduction of oxygen by NADPH oxidase using intracellular NADPH as the substrate, (2) the subsequent dismutation of o2- to from O2 , and (3) the reaction of o2- and NBT. NBT specificity for o2- was analyzed by comparing results in the presence and absence of superoxide dismutase (SOD) which catalyzes the dismutation of o2- to H2o2. Measured PAM heterogeneity was accounted for by varying the concentration of intracellular NADPH, its rate of depletion, and the concentration of intracellular NADPH oxidase in the kinetic model. Model predictions compared favorably with experimental results except when SOD was present. This discrepancy may be due to diffusional limitations since NBT is a relatively small molecule (818 MW) compared to SOD (34000 MW). In addition, the cell surface is both ruffled and negatively charged, which may introduce steric hindrances and/or electrostatic effects since SOD is also negatively charged.

Jan 1, 1988

By G. S. Price

This paper, which describes the milling practice at the Page concentrator of the Federal Mining and Smelting Co., is one of a series being prepared by the Bureau of Mines. The Page mine and mill are located on Silver Creek, 3 miles west of Kellogg, Idaho, and 1 mile south of United States Highway No. 10. Supplies and concentrates are hauled by truck over an automobile road which connects Highway No. 10 with the property. The concentrator has capacity to treat 300 tons of ore per day and utilizes all-flotation methods of treatment. Power is supplied from the main line of the Washington Water Power Co. which runs from Spokane, Wash., to Kellogg, Idaho. Water is obtained from the mine and also from a well which is situated 1 mile distant from the concentrator and about 600 feet in elevation below the concentrator.

Jan 1, 1932

By H. J. Fissan, G. Ananth, K. Rubow, V. Marple

"INTRODUCTION Over the past several years a new type of cascade impactor that utilizes small nozzle diameters (micro-orifice nozzles) has been under development (Kuhlmey et al., 1981; Marple et al., 1981). The small nozzle dimensions allow for particles to be collected as small as 0.024 µm aerodynamic diameter on the last stage of the impactor. To obtain a reasonable flow rate of 30 I min - i through the impactor, a large number of nozzles (up to 2000) are required per stage.Furthermore, by locating the nozzles of multi-nozzle stages in a prescribed manner (described in detail by Marple et al., 1981) and rotating the impaction plates relative to the nozzle plates, uniform deposits can be achieved on the impaction plates. As described by Marple et al. (1981), the advantages of a uniform deposit impactor over the conventional impactor that collects particles only beneath stationary nozzles are: (1) maximum use of the impaction substrate surface, reducing both particle bounce (if substrates are greased) and tare weights of the substrates (if particle mass is measured gravimetrically); (2) deposited particles can be analyzed for elemental composition by X-ray fluorescence (Dzubay and Rieke!, 1978); and (3) the pressure in the impactor can be kept relatively high compared to low pressure impactors that depend on a large slip correction to achieve small particle collection (some types of particles may evaporate at low pressures). The work described in this paper investigates two additional advantages of a uniform deposit impactor. These are: (1) the possibility of collecting two separate deposits at one time on one stage for two types of analysis techniques, and (2) the possibility of utilizing piezoelectric quartz crystal impaction plates more effectively by eliminating the deposit location sensitivity nature of the crystals (Schulze-Frohlich, 1981 ).MICRO-ORIFICE UNIFORM DEPOSIT IMPACTOR (MOUDI)A photograph of an eight-stage MOUDI is shown in Fig. 1. Each stage body of the impactor supports the impaction plate for the stage above and the nozzle plate for the stage below as shown in Fig. 2. By rotating alternate stage bodies, while holding the other stage bodies stationary, the impaction plates (or nozzle plates) will be rotated relative to the nozzle plates (or impaction plates).Rotation of the alternate stage bodies is achieved by gears on these bodies that mesh with gears on an electrically driven drive shaft of a rotating mechanism (Fig. 1 ). The alternate stage bodies are restrained from rotation by pins that rest on the drive shaft."

Mar 1, 1989

By W. C. Phalen

"Tho the term “magnesite” is generally applied to the iron-bearing carbonate of magnesium, such as is found in Austria and Hungary, by some Austrian magnesite is referred to as bruennerite. The mineral bruennerite has become of commercial importance only in Austria. The important deposits are found in Styria, lower Austria and northern Hungary. It is of interest to know that the world's largest deposit of spathic iron ores or iron carbonate (FeCO3), occurs at Eisenerz, Styria, while the world's largest deposit of spathic bruennerite is found at Veitsch in the same province.The Styrian and lower Austrian deposits are located much nearer the Adriatic sea than are the deposits of northern Hungary; and it is from the former that most of the exported magnesite has come. They are located south-west of Vienna, and extend west from Semmering thru the Murz Valley to Tyrol. The chief deposits reckoning from east to west are those of Semmering, Veitsch, Breitenau, Trieben, Radenthein, and Dienten.The largest and most important deposit is that at Veitsch located near Mitterdorf, on the South Austrian railroad in the Murz Valley, Styria. Here the magnesite, which occurs in the form of a lens is quarried on the slope of a hill in a series of terraces about 50 feet apart. The entire work extends thru a vertical distance of 500 feet. The huge magnesite lens is nearly 4 of a mile long and over 1,000 feet in width, and probably extends to a considerable depth.The formation containing the magnesite extends eastward beyond Vienna into Northern Hungary where magnesite is quarried beyond Jolsva and Nyustya in the Gomor district. In spite of the remote location of these deposits as compared with those in Styria, magnesite was shipped from them before the war a distance of 360 miles to the port of Fiume for overseas shipments to other parts of Europe and to America.The average analysis showing the composition of the Austria-Hungary mineral is as follows:The magnesite occurs as lenticular masses in a belt of Carboniferous rocks consisting mainly of metamorphosed Shales, sandstones, conglomerates,,and limestone, It is grayish in color when fresh, and contains sufficient ferrous carbonate to blacken it when calcined. It turns brown owing to the oxide ion of the ferrous carbonate when exposed to the air. The quantity of carbonate of iron is ariable and different analyses show that it ranges up to 13 or 14%For the most part, only the sintered article has been imported into The United States. This material has achieved an enviable reputation for its uniformity both as to chemical and physical characteristics. The homogeneity of the sintered Austrian magnesite is doubtless due in part to the averaging effect of the different operations, such as crushing, dressing, sintering, And mixing, n effect which is not obtainable in mere hand samples.There is comparatively little variability in the sintered magnesite as marketed, and five analyses of this sintered magnesite as quoted by Cornu* are gas follows:"

Aug 1, 1919

By E. J. Gleim

[of- ac tore affecting the e -success of recent conveyor miningsystems forLt. extraction. 1 GL C ,_tfreedom shoot &apos;_)`u 2--ethe.1 is coal while e en othershot firers re:7 t _e&apos; _U-tin , w J, e coal .Z- 311.ing States conveyors because ;-.;lax .ca requires thatblasting be limited to when c .. men os. _o tend neces¬sary officials 1 s . re out c-z ,r 7t ...y e:e l z<: woes no t a -¬#to 1 C" such restriction on blasting conveyor miningbeen extendedWhere ere t ere. re no _ c: t&apos;_ _c tit-----! . kind cutlasting;,1CL?; C&apos;. _ z)carried anI-7LC. AT continuouslyHowever, unless et._&apos;0:, precations are taken under r&apos;t e , accidents, n is or such, as111 electricity r 1C- from.J--_,._.1t ,° =&apos;1?without usingholes, as well as numerous-o _&apos;1&apos;-1 -= e troublehe record of mineexplosions (some of themSo so _C&apos;_ °:&apos;,v 0f rock- dusting]

Jan 1, 1941