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Background Carbon monoxide (CO) is an odorless, colorless gas that can cause illness and death by asphyxiation. Although the toxicity of CO is understood, CO exposure can occur from unrecognized sources. On April 2, 2000, a couple and their newborn infant were poisoned by CO migrating through the ground from blasting at a nearby coal strip mine into their home near Kittanning, Armstrong County, PA. They were treated at the hospital and diagnosed with CO poisoning. The infant had a carboxyhemoglobin level of 31%, the father 28%, and the mother 17%. Carboxyhemoglobin is the compound formed in the blood when CO is breathed. Persons not exposed to CO have carboxyhemoglobin levels of 0.3%-0.7%, and cigarette smokers have levels of up to 9%. Following release from the hospital, the family installed a CO detector in the basement of their home with the help of the local fire department. This Technology News briefly describes this incident to help increase awareness of the problem. It is discussed in more detail by Eltschlager et al. [2001]. Figure 1 shows the coal strip mine believed to have generated the CO. The initial suspect for the source of the CO was the furnace in the house. Only later did it become apparent that blasting at the nearby strip mine might be the culprit. A State investigation concluded that CO had migrated approximately 500ft from the blast, through the ground, and into the home. Figure 2 shows the locations and order of blasts at the mine. Initially, the mine did not plan to blast. Overburden generally consisted of weathered shale that could be dug without blasting. However, the mine decided to blast when hard sandstone that could not be dug out was encountered within 3 ft of the coal top. The blasting was intended to break up the sandstone. Blasting was done using bulk ammonium nitrate-fuel oil (ANFO) in 6.25-in holes 25-30 ft deep on a 16-ft by 16-ft pattern, with charge weights ranging from 17 to 170 lb. The closest blast to the home was 430 ft on April 17, 2000. The distance from the home to the blast area on the day when CO was first reported (March 31, 2000) was 500 ft. Twenty blasts were detonated at the mine between March 7, 2000, and April 20,2000. The blaster was careful to prevent fly rock since another home was only 150 ft away and a garage was 50 ft away. The quantity of explosive used in the blasts was sufficient to break the sandstone, but was less than would normally be used to blast overburden. The holes were typically one-third explosive and two-thirds stemming, with powder factors averaging 0.43 lb/yd3. Additionally, the muck was not immediately excavated after each blast. The heavy confinement on the explosive acted to prevent the typical release of blasting fumes into the atmosphere. Instances of CO migrating from blasts into homes have occurred before, but generally the distances involved were under 150 ft. It is believed that the blast design contributed to the confinement of CO in the ground, and discontinuities in the ground strata facilitated migration toward the residence. Upon inspection of the blast pitwall, a regular system of joints was observed. These joints are oriented roughly from the blast pit toward the house (figures 3-4).Blast-generated CO appears to have been driven into the joint system, displacing the air. When the joint system was saturated, the next succeeding blast pushed the CO into an uncased well next to the house (a high level of CO has been measured in the well shortly after a blast). From there, the CO entered the French drain system and then the basement of the house. The joints are vertical cracks through rock layers that occur on a regular spacing (figure 3). They are most common near valley slopes and are caused when valley walls converge as the stream cuts down through the rock layers. Often called hill seams, they roughly parallel the valley walls, but can curve and split, creating a pathway for gas movement (figure 5). These fractures are often encountered when underground mining proceeds close to outcrop. The system of fractures at the Kittanning blast pit was well developed and provided a path for transmission of CO both through the sandstone and up and through the overlying shales. Blasting engineers should be able to distinguish naturally occurring fractures from blast fractures and note the frequency, development, and orientation of the hill seams and their proximity to occupied houses. The limits of transmission of

May 1, 2001

By J. J. Jakosky, D. H. Zellers

"IntroductionThe Bureau of Mines has been conducting experiments in underground communication during a period of several years, and a brief summary of what has been done is as follows:During 1919-1920, investigations were conducted with the geophone. This instrument was used extensively during the World War for detecting enemy digging and mining operations, by means of the vibrations transmitted through the earth strata.A preliminary investigation using short wave-length (200 to 300 meters) radio equipment carried out jointly with engineers of the Westinghouse Electric & Mfg, Co. during 1922.The step was to investigate ground conduction signaling, (called T.P.S. in Signal Corps parlance)."

Nov 1, 1924

By G. L. Neumann

"INTRODUCTION AND SUMMARYThe Guymard mine in Orange County, N. Y., is reported to have been discovered in 1862 and mined until 1876, producing 10,000 tons of lead and zinc ore. 2/The property was examined by an engineer of the Bureau of Mines 3/ in 1948. Development work was done by the Bureau in April and May 1949 and March 1950. During these two periods four drill holes totaling 2,090 feet were completed. The mineralized sections of the core were sampled and assayed.ACKNOWLEDGMENTSThe diamond drilling was conducted under the general supervision of McHenry Mosier, chief, Mining Development Branch, Minerals Technology Division, Region VIII, and the direct supervision of Kenneth M. Earl and the writer as project engineers. Drill cores were logged by Paul K. Sims of the Federal Geological Survey. Chemical analyses were made by the Bruce Williams laboratories, Joplin, Mo., and the Minerals Processing Branch, Minerals Technology Division, Region VIII, Bureau of Mines, under the general supervision of Paul M. Ambrose, chief, and the direct supervision of Howard F. Carl, chief, Physical and Chemical Section.LOCATION AND ACCESSIBILITYThe Guymard deposit (see fig. 1) is on the west slope of Mount Hope, Orange County, N. Y., 1,500 feet northeast of Lake Guymard.Graham station, near the deposit, is on the Erie Railroad about 8 miles north of Port Jervis and 4 miles south of Otisville."

Aug 1, 1952

By E. D. Gardner, Edmund Stein

"IntroductionMassive sulphides occurring in metal mines are inflammable and furnish the fuel for many mine fires. Actual sampling has shown that dangerous amounts of sulphur dioxide and hydrogen sulphide may occur in mine atmospheres after blasting in massive sulphides. Probably some .of the finer sulphide in the material being blasted burns while it is in contact with the flame from the explosion. It’s also possible that oxygen of the explosive enters into the reaction.That sulphide dusts are explosive under some conditions has long been suspected, but the theory has not been generally accepted as having been proved. Evidence now at hand appears to be conclusive that such explosions do occasionally occur in mine workings in massive sulphides. Information from several mines working in heavy sulphides shows that occasionally, sulphur dioxide in larger amounts than could be expected from the blasting alone are occasionally thrown out into the mine atmosphere during blasting. Accidents have occurred and lives have been lost by men being caught in such gases. Also it appears in a few cases that damage done to timber in stopes by concussions has been greater than could 112.ve been expected from the regular blasts. In most of these cases the unusually large amounts of Sulphur dioxide could only be accounted for by an explosion or by an ignition of sulphide dusts. When this occurs it is probable that the settled dust is stirred up by the first shot of a round, then the dust cloud is ignited by this or a succeeding shot.In one instance, the senior author, while wearing breathing apparatus, returned to a station to take a gas sample immediately after a raise round had been blasted, and encountered a heavy white fume or smoke that was corrosive to the skin and which forced a retreat. The sample, which was taken farther back in a greatly diluted atmosphere, showed a high percentage (0.18) of sulphur dioxide. The station and the raise which was just being started were very dry and the walls and floor of the station contained settled sulphide dust which apparently was ignited by the blast."

Mar 1, 1928

Effective control of respirable dust is one of the most serious problems associated with longwall mining in the United States. This report describes the development and laboratory testing of dust collectors for use on double drum shearers. Systems tested included: ? High Capacity Flooded Bed Scrubber ? Water Powered Extraction Cowls ? Water Powered Extraction Drums ? Water Powered spot Scrubbers. The systems were tested using tracer gas in a full-scale model of a longwall shearer face. This report provides a detailed description of the test facility, test methods, and system test results.

Jan 1, 1982

By Stephen A. Hare, O&apos

Powder metallurgy processing of commercial Raney nickel powders was examined. The typical angular particle shape, in conjuction with aluminum present in a eutectic phase, facilitated interlocking leading to excellent green strength after compaction. Density and porosity as influenced by the compacting pressure were studied over the range of 37.5 to 207 meganewton per square meter (MN/m2). Sintering in an inert atmosphere from 575° to 850° C caused a volume increase which is attributed to a solid state reaction between Al and Ni2Al3 phases. The reaction is 3Al + Ni2Al3 ? 2NiA13. A thermal pretreatment of 70 hours at 700° C was required to prevent this reaction from occurring during sintering. Density and porosity as a function of compacting pressure and sintering temperature were determined after a thermal pretreatment of the powder.

Jan 1, 1976

By B. K. Cantrell, K. L. Rubow

"Quantifying exposure to diesel exhaust aerosol in an underground coal mine depends on the ability to measure this component of respirable mine aerosol separately from coal dust. Such measurement is complicated by the carbonaceous nature of both the diesel and coal dust particulate that make up the respirable aerosol. Hence, special sampling and analytical techniques must be used to distinguish between these two aerosol components.As part of a continuing study of diesel exhaust aerosol characteristics, the U.S. Bureau of Mines has applied size selective sampling together with gravimetric analysis to separate and measure respirable diesel exhaust and coal dust aerosol concentrations in diesel-equipped underground coal mines. This technique is based on the premise that the diesel portion of the aerosol is predominantly submicrometer and the mineral dust portion is mostly greater than 1 µm in size. In the study, chemical mass balance (CMB) modeling, based on the distribution of chemical elements in aerosol and aerosol source material samples, is used to referee the analysis of diesel exhaust and mineral dust aerosol concentrations from the size selective sampling results.Based on the results of the study, the Bureau, in cooperation with the University of Minnesota and the U.S. Mine Safety and Health Administration (MSHA), have developed a prototype personal diesel exhaust aerosol sampler for underground coal mines. The sampler has three stages: a preclassifier stage to select for respirable aerosol, an inertial impaction stage with an aerodynamic diameter(d) size cut at 0.8 µm to separate diesel aerosol from mineral dust and collect the mineral dust, and a final filtration stage to collect the diesel fraction of the sample. The sampler has been evaluated in both laboratory and field experiments conducted by the Bureau, MSHA, and the Generic Minerals Technology Center for Respirable Dust (GMTC-RD)."

Mar 1, 1992

By David P. Lindroth

The objective of this research by the Bureau of Mines was to determine the technical feasibility and associated pilot data for drying minus 1/4-in coal with microwave energy at a frequency of 2.45 GHz. The drying data were obtained experimentally on three coal types: bituminous, subbituminous, and lignite. The experiments were performed with a custom-designed conveyorized microwave oven having a continuous power capability of 12 kW. Drying efficiencies near the theoretical maximum of 1.54 kg of water per kilowatt hour of energy input were achieved for two coals and two sizes; overall drying efficiencies averaged 77 pct.

Jan 1, 1986

By Chas. E. van Baraeveld

"The information presented in this report is a by-product of studies concerning zinc, and is published in response to various inquiries for information as to the suitability of zinc for roofing. It parallels a previous report of the Bureau of Mines on slate roofing.Available Forms of Zinc RoofingZinc is available for roofing in three forms: 1. As sheet zinc which may be used advantageously on roofs with as flat a pitch as 1 in 4; laid with standing seam construction for small roofs and with batten construction for large roofs. 2. As corrugate sheets, in widths up to 40 inches and in lengths up to 8 and feet, available for siding and roofing in industrial buildings (with certain re¬strict ions) and or farm buildings (without restrictions). 3. In the form of shingles.Advantages of Zinc Roofing1. Zinc is a permeant roofing material; that is, when suited to the conditions, and properly applied to a roof designed with the right purlin spacing it will outlast the building and still have a salvage value equal to a least half the original material cost. It is applicable to a wide range of conditions, from the most expensive to the cheapest type of construction, and is not greatly above the cheaper materials in first cost. A permanent roof of simple outline need not cost over $15 to $25 per square (100 square feet), depending upon the method of construction required a corrugated sheet roof for industrial purposes or for farm use need not cost over $15 per square for ordinary conditions. 3. Corrugated zinc sheets have the distinct advantage of being available for re-use and re-construction if handled with ordinary care. 4. Zinc oxidizes to a certain point, building up a strong protective coating which in time effectually checks further oxidation; thus it does not oxidize to the point of destruction as steel does, 5. It is light and easily handled."

Nov 1, 1924

By W. H. Carrington, A. C. Richardson

"INTRODUCTION The Powhatan mine of the Franklin Coal Mining Co. is located in the western part of Jefferson County, Ala., on the Louisville and Nashville Railroad, 40 miles west of Birmingham. The Mary Lee bed at this point yields coal with fair coking qualities, but with an ash content as mined so high as to prohibit its use in the production of metallurgical coke. At present the entire output of the mine is washed in single-compartment jigs and marketed as locomotive and domestic fuel.Figure 1 gives a typical seam section of the Mary Lee bed at the Powhatan mine. This section shows that the bed is divided by rock partings into three benches. In many parts of the mine, particularly in the older workings the roof rock is so weak that it can not be held without excessive timbering. This condition has restricted the operation in many parts of the mins to the middle and bottom benches of coal. The 6 inches of draw rock between the top and middle benches is very strong and makes an excellent roof requiring only a normal amount of timbering to support it. In the newer workings of the mine the character of the rock above the top bench is strong and it is believed that in the future it will be possible to work all three benches. This study was undertaken for the purpose of determining the washing characteristics of the Mary Lee bed at Powhatan and the effect on these characteris-tics of including or omitting the coal from the top bench. It was also the purpose of the study to show whether it would be possible to produce a washed product sufficiently low in ash to be used for the manufacture of metallurgical coke. This paper is one of a series of reports on the washability of Alabama coals which is being prepared by the U. S. Bureau of Mines and tin University of Alabama. With the cooperation of the coal producers of Alabama. It contains the results of screen sizing and float-and-sink tests of representative samples of run-of-mine coal, and the results of table tests on the minus 3/16-inch sizes of the raw coal."

Apr 1, 1933

By Jack I. Paige

The devitrification of lithium silicate glasses was studied to determine the effect of annealing temperature, composition, and additives on nucleation and crystallization. High-purity glasses, prepared from reagent-grade chemicals, had close to optical quality when prepared by a vacuum induction melting method developed during this research, The progress of devitrification was traced by differential thermal analysis and thermal expansion for those lithium metasilicate-silica compositions containing 80 to 90 percent silica. Microscopic studies of glasses partially devitrified at various temperatures and annealing times indicated that the primary initial mode of formation of individual crystals ,vas from densely crystalline zones that filled in as crystallization advanced Of the additives tested, calcium, potassium, and sodium helped promote devitrification with the least cracking or surface deformation. Tin oxide was most effective in reducing volume contrast ion during devitrification, but was not ClS effective in preventing cracking as calcium or potassium additions.

Jan 1, 1965

By Joseph A. DeCarlo

According to the annual survey of beehive-coke plants by the Bureau of Mines, United States Department of the Interior, there were 61 plants with 9,549 ovens in the United States on December 31, 1956, This publication in¬cludes only those for which an annual report was filed with the Bureau of Mines. Not all plants listed were active, however, as nearly one-third of those canvassed were idle all year. A compilation of the returns showed that 44 plants with 6,920 ovens were active part or all year and 17 plants with 2,629 ovens were idle throughout the year. The capacity of beehive ovens has fluctuated between 6 and 14 million tons during the past decade. At the end of 1956, the annual coke capacity of beehive ovens on which reports were received amounted to 5.8 million tons. As noted in table 2, however, not all of this capacity was in operating condition, as 2,093 ovens with a capacity of 1.2 million tons were not operable on [ember] 31, 1956.

Jan 1, 1958

By Richard L. Fowler

Study and development of sensing techniques and sensors were performed to aid shuttle car drivers in detecting obstacles and in guiding the car along the face haulage route. Microwave, acoustic, and optical sensing techniques were considered as part of the feasibility study for obstacle detection. Various guidance techniques, including wire-following and rib-ranging were investigated. Active optical sensing was selected for obstacle detection to obtain the beam coverage and sharp angular cutoff characteristics required within the packaging limitations defined by the shuttle car configuration. Rib-ranging guidance was selected to achieve a completely self-contained shuttle car system which responds to the existing mine geometry without need for wires, stripes, or other path defining devices. Extensive hybrid computer simulation runs were performed to evaluate various guidance techniques during the feasibility study. Subsequent simulation runs were performed to establish parameter values for the rib-ranging guidance system. The obstacle detection and guidance system was designed, fabricated and installed on a standard shuttle car. The system satisfied all applicable permissibility requirements of Schedule 2G. An experimental permit was issued to Bendix for operation in an underground coal mine. System evaluation tests were performed first above ground at the Bendix Research Laboratories. The simulation model was validated by these runs. Final testing was performed underground in an operating mine with an experienced shuttle car driver. All sensors successfully demonstrated the predicted performance capability during underground face haulage tests. Dust did not impair system performance and lens cleaning was not required during working shifts. Further development is required to achieve the desired obstacle detection performance. Closed loop steering control with manual override is recommended for the lateral guidance system. The guidance system should be an invaluable aid to low-coal shuttle car drivers where continuous mining machines are utilized.

Jan 1, 1973

By R. V. Lundquist

A method was developed by the Federal Bureau of Mines for evaluating viscosity data from slurries obtained in leaching sinters from the lime soda sinter process for extracting alumina from aluminous silicates. The logarithm of the viscosity was observed to be a linear function with time. The slope of the plotted line provides a means for evaluating viscosity behavior in a lime soda sinter blurry and also a means for comparing gelation characteristics directly with other variables in the lime soda sinter process. This report presents one aspect of a continuing study by the Bureau of Mines on methods for treating siliceous aluminum ores. It is one of the many programs of the Bureau concerned with conservation, development, and use of our domestic minerals resources. Previous investigations of lime soda processes, both by the Bureau4-7/ and industrial concerns, have demonstrated that sintered materials containing CaO, Na2O, A1203, and S102 in various combinations exhibit a tendency to gel or set when mixed with water or other extraction solutions. Gelling prevents satisfactory recovery of alumina and in extreme cases prevents operation of an extraction plant.

Jan 1, 1960

By Robert W. Geehan

A preliminary examination of the Dayton iron deposit was made in 1941 and 1942 by Paul E. Pesonen and O. H. Metzger, engineers of the Bureau of Nines. Trenching and sampling were recommended, to be followed by core drilling if favorable results were obtained. The Bureau of Mines conducted a project at the property from June to December 1942. The deposit is in sec. 6, T. 17 N., R. 23 E.; sec. 31, T. 18 N., R. 23 E.; sec. 36, T. 18 N., R. 22 E.; and sec. 1, T. 17 N., R. 22 E., M. D. B. & M., about 15 miles west of Lahontan Reservoir in Lyon and Storey Counties, Nev. It lies at an altitude of about 4,500 feet north of the Carson Plains, in the foothill section of mountains that rise to about 7,000 feet to the north of the property. The deposit may be reached by driving 12.5 miles northeast of Dayton over U. S. Highway 50, thence northerly 2.7 miles over a dirt road to the property. The climate is hot and dry in summer, with occasional thunderstorms some of cloudburst variety, and frequent high winds. Winters are usually moderate, with light snowfall and some subfreezing temperature.

Jan 1, 1949

By Charles D. Litton

This Bureau of Mines report presents a discussion of the essential components of pneumatic monitoring systems and their associated functions. Design criteria are presented which can be used for the design and fabrication of pneumatic monitoring systems having total system response times on the order of 15 to 30 min. To illustrate the utility of these design criteria, two detailed design examples are presented,

Jan 1, 1983

By Douglas F. Scott

This case study provides an example of how social marketing was applied to meet the needs of business customers. Federal regulations require that all companies develop a written program to track hazardous chemicals at their sites. The HazCom Writer, created by the National Institute for Occupational Safety and Health (NIOSH), is a software tool designed to help companies prepare their required Hazard Communications (HazCom) written plan and list all hazardous chemicals at the company's worksite. The social marketing goal was to provide a product for small- to medium-sized companies to use for federal HazCom rule compliance. The HazCom Wm'ter is a direct NIOSH response to customer and stakeholder needs (including the Mine Safety and Health Administration, the mining community, and Occupational Safety and Health Administration- regulated companies).

Jan 1, 2009

By Nabil A. Bibawy

An improved method for preparing gravimetric standard gas mixtures of helium-4 in nitrogen has been developed by the U.S. Bureau of Mines. A single-pan 12-kg analytical balance that has a sensitivity of 3 mg is used to prepare the mixture. The balance will accommodate a cylinder having a volume of approximately 4 L that weighs approximately 5 kg. The method has been improved to a precision of ±O.04 pct by performing four successive dilutions, by improved handling of gases in the manifold, and by using an improved analytical method to select high-purity gases.

Jan 1, 1990

By James S. Browning

Heavy liquids have been used to separate minerals of different specific gravities for many years.4 5 6 7 8 9/ The method permits substantially quantitative evaluation of a variety of minerals and requires much less time than the usual methods of chemical analysis. This Bureau of Mines investigation was conducted to determine the applicability of heavy liquid mineral separation to the evaluation of certain spodumene and kyanite ores, prepared mixtures, and plant products. After careful standardization of the particular mineral and associated gangue, estimates of chemical analyses could be obtained from results of heavy liquid separations.

Jan 1, 1960

By Andrew W. Berg

The Bureau of Mines Mineral Industry Location System (MILS) is part of the computerized Minerals Availability System (MAS), a comprehensive data base of known mineral deposits. MILS, the location subsystem of MAS, has become widely used by the minerals industry and organizations with land-use planning and land management responsibilities. Information on more than 135,000 mineral locations and processing plants in the United States is contained in the data base. This information includes the name, location, mineral commodity, type of operation, bibliography, and cross-references for each property or prospect. Computer-drawn map overlays at various scales showing clustered MILS locations and computer printouts keyed to those overlays are available for inspection and reproduction at the Bureau's Field Operations Centers at Juneau, Alaska, Denver, Colo., Pittsburgh, Pa., and Spokane, Wash.

Jan 1, 1979