Search Documents

By H. H. Schrenk

There is a need for a method of determining benzene vapor in air which is simple and accurate and suitable for making industrial hygiene surveys. The most widely used method in this country is the Smyth modification of the Elliott and Dalton procedure. This depends on the nitration of the benzene to m-dinitrobenzene, reduction to phenylenediamine with an excess of standard titanous chloride solution, and back titration with a standard ferric ammonium sulphate solution. This method has the disadvantages of being somewhat time-consuming and cumbersome; it requires considerable apparatus, and a special modification is necessary in the presence of toluene. Recently Cook and Ficklen have published a method based on the oxidation of benzene with hydrogen peroxide in the presence of iron salts. This method requires the use of solid carbon dioxide to freeze out the benzene. The reaction Which produces the color is complex; and only approximate quantitative estimations can be made, except in a very narrow range.

Jan 1, 1935

By Jr. Boyle

This report analyzes the availability of chromium in the form of ferroalloy products (high-carbon and low-carbon ferrochromium and ferrochromium-silicon) and chromite products (metallurgical, chemical, refractory, and foundry sands) in market economy countries (MEC's). A total of 873.5 Mmt of in situ material, containing 202.5 Mmt of chromium, in 10 MEC countries was analyzed for availability as of the January 1989 study date. Extraction and beneficiation of this in situ material would result in 475.4 Mmt of marketable chromite products. As analyzed, 288.5 Mmt of these chromite products would be available for export or for internal chemical and refractory use and 186.9 Mmt would be smelted in-country to produce 74.3 Mmt of high-carbon ferrochromium, 3.9 Mmt of low-carbon ferrochromium, and 2.0 Mmt of ferrochromium-silicon, all available for export. A network flow model, which includes centrally planned economy countries (CPEC's), was also constructed to analyze world chromium supply and demand interactions for the period 1986 through 1994 and to address a hypothetical North American embargo on direct imports of all South African chromium products beginning in mid-1990. The model shows capacity constraints developing in the MEC high-carbon ferro chromium industry in 1987 and a possible subsequent overreaction by the industry in terms of new capacity additions. The results suggest that sufficient chromium is available to North America should an embargo on direct imports from South Africa be imposed by its governments. However, the effect on export revenues in South Africa is relatively small, and timely increases to world ferrochromium, chemical chromite, and foundry sand chromite capacities would be required.

Jan 1, 1993

By Ralph B. Stevens

The objective of the Automatic Fire Sensing and Suppression Systems for Mobile Mining Equipment program is to document the design, fabrication, factory testing, 11-month in-mine testing, and final demonstrations of auto¬matic fire protection systems on several units of mobile mining equipment including trucks, front-end loaders, cranes, draglines, coal haulers, and cutters. Proper sealing of all system components from the elements, especially in corrosive mine conditions, is essential for reasonable life-cycles with minimum maintenance. Also, adequate power supplies, wire, connectors, and plumbing with adequate protection from the harsh mine environments and physical damage were necessary during the in-mine tests. The fire protection systems were developed from technology employed during two previous Bureau of Mines contracts: HO122053, Improved Sensors and Fire Sensing Systems for Mining Equipment, and H0232059, Validation Testing of Truck Fire Protection Systems.

Jan 1, 1978

By J. E. Fraley

This report describes the preliminary results of a Bureau program to develop and test an inexpensive grout for full-column support of roof bolts. Various inorganic grouts were tested in both cartridge and slurry form. Tests were also performed on methods of water packaging and on the effect of fillers on the grout strength. Results showed that some grouts had poor early strength and exceptional mid-to long-term strength. Laboratory tests have shown that rapid-setting inorganic grout could be an economical replacement for resin bolts if the short-term strength could be increased. Further development to improve its early strength would need to be tested in the laboratory and underground to prove its potential for the mining industry.

Jan 1, 1987

By E. G. King

Many of the existing thermodynamic values for the titanium halides are estimates, including all the entropies and high-temperature heat contents of their crystalline and liquid phases. This report contains the results of low-temperature heat capacity measurents (which lead to entropy values at 298.15° K,) and high-temperature heat-content measurements of four halides - trichloride, tribromide, tetrabromide, and tetraiodide. The new data are combined with selected heat-of-formation values at 298.15° K. to obtain improved values of the heats and free energies of formation of these halides at high temperatures, thus supplementing the previous data of Kelley and Mah.5/ ACKNOWLEDGEMENTS This investigation was conducted under a cooperative arrangement between the Federal Bureau of Mines and the Department of the Navy, Office of Naval Research. The work was done by Bureau of Mines personnel using Bureau of Mines calorimetric equipment. The Office-of Naval Research supplied the supporting funds and arranged for procuring the samples of the titanium halides. The samples were prepared and analyzed by the Inorganic Chemistry Section, Division of Chemistry, National Bureau of Standards.

Jan 1, 1961

By Raymond B. Ladoo

[Inquiries are frequently received by the Bureau of Minas relative to occurrence, mining, treatment and utilization of the natural hydrocarbons' such as gilsonite, elaterate, wurtzilite, grahamite, and ozokerite although have been known and used for many years, they are not yet well understood and the amount of recent literature dealing with them as comparatively small. This paper is intended merely to summarize the present knowledge The natural hydrocarbons included in this series are gilsonite, elaterite, wurtzilite, glance pitch, manjak, grahamite, albertite, arid ozokerite and many other minor varieties. With the exception of ozokerite and the other mineral waxes, then all more or less resemble asphalt in that they are dark brown or black bituminous substances of organic origin, generally with a resinous luster. Ozokerite usually light an color with a waxey luster, is closely allied to the others of the series, but is usually considered separately, Unfortunately authorities differ as to nomenclature so that determinations of physical and chemical properties from different sources may riot be readily compared. Abraham Herbert, Asphalts and Allied Substances, 1918, 606 pp. has made one of the most detailed studies of these subjects in recent years, and his classification is used in the main. The following definitions are given by him]

Jan 1, 1920

By Oliver Bowles

[The inorganic nonmetallics - that is, all minerals aid their primary products except metallic ores and fuels - have an important place in industrial life of any country. They are essential to a multitude of products and processes, and their development is closely related to general industrial activity. Several are classed as strategic, and many others are performing necessary functions in the military program. It may be of interest therefore to trace their history over a period of years and to correlate their progress with the circumstances and events that are shaping national]

Jan 1, 1943

By D. R. Tesarik

As part of its research program to investigate ways of improving resource recovery and reducing subsidence, researchers from the U.S. Bureau of Mines placed instruments in the B-North ore body of the Cannon Mine, Wenatchee, WA, to monitor cemented backfill and rock deformation during mining. The vibrating-wire gauges proved to be reliable and versatile, and approximately half of the instruments are providing data after 2 years of use. A two-dimensional, finite-element model was used to analyze the Cannon Mine's multilevel bench cut-and-fill mining method and predict rock and backfill displacements. The model accurately predicted rock displacements, but the predicted and measured displacements in cemented backfill had a correlation coefficient near zero, indicating that the model should only be used to predict rock displacements and not backfill displacements. A finite-difference model was also used to evaluate the stability of a cemented backfill pillar. Results can be used to conservatively predict backfill stresses, but on-site observation of pillar failures coupled with in situ measurements are needed to make more accurate predictions. An ongoing evaluation of the mining system has indicated that filling the primary stopes tight to the back with cemented backfill allowed these pillars to carry overburden loads soon after the cemented backfill was placed.

Jan 1, 2010

By A. U. Miller

Definite progress has been made in accident prevention in Illinois during the past few years; the State Department of Mines and Minerals is receiving excellent cooperation from coal companies and employees, the companies are making greater effort to maintain their mines in good condi- tion, and the employees are eliminating more unsafe practices. As a result, some coal companies have made commendable safety records that prove that coal can be mined with a comparatively low accident rate. However, there is need for further improvement, as the accident rate of the State as a whole is much higher than it should be. During the 55-year period 1882-1936, in- clusive, reports of the State Department of Mines and Minerals show a total of 7,005 (an average of 127.36 per year) men killed in and around the coal mines. Of this number, 6,425 (91.7 percent) were killed underground, 346 (4.9 percent) in the shaft, and 234 (3.3 percent) on the surface. Of the fatalities underground, 3,300 (51.3 percent) were killed by falls of roof, sides, or face coal, 1,167 (18.1 percent) by haulage, 639 (9.9 percent) by handling explosives, 579 (9 percent) by explosions, 151 (2.3 percent) by electricity, and 589 (9.1 percent) by other means. Of the fatalities in the shaft, 171 men (46.5 percent) were killed by falling down the shaft, 14 (41.6 percent) by the cage, and 31 (8.9 percent) otherwise. On the surface, 113 (48.2 percent) of the fatalities were due to railroad cars, 51 (21.7 percent) to machinery, and 70 (29.9 percent) to other causes. The fact that 7,005 lives (an average of 127.36 per year) were lost during 1882-1936 is sufficient evidence that in the past too little interest has been taken in safety by either the management or workers. A realization of this deplorable loss of life should act as an incentive to the industry to make greater effort to prevent accidents in the future. After an accident occurs, the facts pertaining to it become history, and anything that may be done afterward cannot change in any way the damage that has already been done, such as loss of life, personal injury, and destruction of property. The main benefit that can be derived from an acci- dent is that suitable procedure may be adopted and some lesson may be learned to aid in preventing a similar accident in the future. All accidents, par- ticularly serious ones, therefore should be investigated and an effort made

Apr 1, 1938

By E. G. Noble

The effects of HBr concentration and temperature on the solubility and hydration state of AlBr3,' CoBr2, PbBr2, MnBr2, KBr, and NaBr were investigated by the Bureau of Mines. Saturated aqueous solutions of the AI, Pb, K, and Na bromides were sparged with HBr gas at 20°, 40°, and 60° C, and saturated solutions of Co and Mn bromides were sparged at 20° C. Increased HBr concentration caused decreased salt solubility because of the common ion effect for all the investigated bromides except PbBr2. Aqueous solubilities at 20° C were, in percent, 51.7 for AlBr3, 53.2 for CoBr2, 1.1 for PbBr2, 59.6 for MnBr2' 39.5 for KBr, and 47.4 for NaBr. At 60° C, the solubilities were, in percent, 53.3 for AlBr3, 2.2 for PbBr2' 46.0 for KBr, and 53.8 for NaBr. Solubilities in solutions sparged to HBr saturation at 20° C were, in percent, 0.5 for AlBr3, 42.0 for CoBr2, 32.2 for PbBr2, 21.0 for MnBr2, 0.6 for KBr, and 0.3 for NaBr. At 60° C, the solubilities at HBr saturation were, in percent, 1.8 for AlBr3, 41.4 for PbBr2, 1.3 for KBr, and 0.4 for NaBr. CoBr2 precipitated out to a minimum solubility of 27.2 pct at 28.7-pct-HBr concentration. Further increases in HBr concentration increased CoBr2 solubility because of the formation of bromide complexes. PbBr2 in-creased in solubility as HBr concentration increased.

Jan 1, 1988

By Keith L. Harris

The U.S. economy continued to grow moderately in the third quarter, but at a slightly higher rate than in the previous quarter. According to the Department of Commerce's preliminary estimate, real gross national product (GNP) grew at a seasonally adjusted annual rate of 3.3% during the third quarter of 1985, compared with a revised 1.9% for the second quarter and 1.6% for the third quarter of 1984 (table 1). Civilian unemployment dropped from the constant 7.3% rate between February and July to 7.0% in August and 7.1% in September. Employment on nonagricultural payrolls continued to increase (table 2), resulting in a continued rise in personal income, which in turn supported growing consumer purchases. Although purchases of services continued to provide the underlying foundation for the economic growth, the manufacturing sector received additional stimulus from significant increases in consumer purchases of durable goods, particularly automobiles. The increased demand for durable goods resulted in significantly higher industrial production for August and September, compared with levels attained previously this year (table 3). Capacity utilization increased to 80.5% in August but returned to 80.2% in September, matching the 1985 low previously reached in July (table 4). The real net export deficit grew only $0.2 billion in the third quarter; at $34.0 billion, however, it continued to exert a negative influence on the economy. On September 22, in an effort to reduce the deficit and make U.S. goods more competitive on world markets, the U.S. Government agreed to cooperate with the Governments of France, the Federal Republic of Germany, Japan, and the United Kingdom in attempting to lower the-value of the dollar in relation to other world currencies. Low inventories, rising factory orders and construction spending, the possibility of a lower U.S. dollar, and aggressive automobile production plans announced by domestic producers for the fourth quarter indicate the potential for an increase in manufacturing activity in the United States.

Jan 1, 1985

By Charles L. Kusik

A study was conducted for the Bureau of Mines, U.S. Department of the Interior, to provide information which will lead to an increase in the recycling of mineral materials, in order to help conserve the Nation's mineral resources. Data were collected on energy requirements to recycle prompt industrial and obsolete scrap for nine metal commodities: Iron and steel, aluminum, copper, zinc, lead, stainless steel, titanium, tin, and nickel and nickel alloys. Major process routes for recycling were considered, starting from the first collection point through scrap preparation, transportation, smelting and/or refining to the molten metal, ingot, or other semi- finished form approximately equivalent to a primary metal of a similar composition. Available data for 1976 were collected on the amounts of each metal commodity recycled by major scrap categories. In addition, energy requirements were estimated for separating municipal solid wastes into four major categories: Refuse-derived fuel, and magnetic, aluminum, and glass cullet fractions. Finally, areas of research were identified to enhance recycling and/or increase the efficiency of energy use.

Jan 1, 1978

By Thomas C. Denton

In 1965 Africa maintained its position as a region of the world essential to advanced non-Communist nations for supply of vital metals and minerals. The position stemmed from the fact that Africa produced in large quantity a number of key minerals of which either or both resources and production capacity elsewhere did not approach the needs of the free world. The Republic of South Africa alone contributed more than three quarters of the gold mined in the entire non-Communist world besides an estimated 60 percent of metals of the platinum group and the entire new supply of amosite asbestos, and Africa as a whole was nearly the non-Communist world's only source of gem and industrial diamond. Africa also accounted for 83 percent of non-Communist world cobalt production. Besides these massive contributions, Africa in 1965 provided 50 percent or more of the new supply from non-Communist countries of the following mineral commodities: Lithium minerals, corundum, manganese ore: and chromite, and over 20 percent of new supply from non-Communist countries of columbium-tantalum concentrates, antimony, beryl, vanadium, phosphate rock, and copper. Africa also accounted for 18 percent of the non-Communist world's output of uranium, 14 percent of its tin, 11 percent of its lead, 9 percent of its zinc, and 8.9 percent of its crude oil output. With respect to chromite, at yearend Africa's reserves of the mineral were far larger than those of all other non-Communist regions combined. This probably also held true for manganese ore. In the case of crude oil, the fact that Africa's share of non-Communist world output was 1.6 percentage points greater than in 1964 was significant, particularly inasmuch as the output rate was continuing to increase at yearend.

Jan 1, 1967

By Daniel G. DiCanio

This report describes a computer-based model for estimating the tangible costs of injuries and deaths from work-related accidents in underground coal mines. The study undertook to identify and quantify the elements of accident costs, including field visits to coal mines, insurance carriers, and public agencies. The mathematical models developed for each tangible element of accident cost are presented in Volume I of the report. A listing of the computer programs which comprise the model and instructions for using the programs are presented in Volume II. Statistical distributions of mining family characteristics, data on 95 miners killed in underground accidents, and other basic data used to develop the model are presented in Volume III. Application of the model to a data base of 9,286 accidents which occured in underground bituminous coal mines during 1974 yielded a total of $56,900,000 in tangible costs to industry, mining families, and public agencies. Loss of income to the families of miners injured or killed in these accidents accounted for 47 percent of the total.

Jan 1, 1976

By Olman Hee

This study investigates the identity and relative importance of factors affecting the future demand for phosphate rock, potash, and nitrogen. The main objective is to analyze demand relationships for these chemical raw materials for some specified past period, and to utilize this information to make projections of consumption into some designated future period. The end-use approach is used, which divides total consumption of each chemical raw material into agricultural, industrial, and export use. Multiple regression analysis is employed to statistically measure the relative effects of the different factors on consumption in each end use. The general method centers on the construction of a consumer demand model, the fitting of the respective equations in the model, and the interpretation of the statistical results. Direct and cross price elasticities of demand are computed for each end use of the chemical raw materials. These give an insight into expected changes in consumption with respect to given changes in price. The results of this study indicate that price, consumer income, and level of technology are factors which measurably affect consumption of chemical raw materials. For phosphate rock and potash, the agricultural and industrial end uses showed an inelastic demand, whereas for nitrogen, all end uses (including export use) exhibited an elastic demand. Among the chemical raw materials, average annual growth of consumption of nitrogen for agricultural and export uses to 1980 is expected to be notably higher than that for phosphate rock and potash.

Jan 1, 1969

By Steven J. Page

Since 1982 standard calibration materials recommended for respirable crystalline silica analysis by the Mine Safety and Health Administration (MSHA) P7 Infrared Method and the National Institute for Occupational Safety and Health (NIOSH) X-ray Diffraction (XRD) Analytical Method 7500 have undergone minor changes in size distribution. However, a critical assumption has been made that the crystalline silica in ambient mine atmosphere respirable dust samples has also remained essentially unchanged in particle size distribution. The objective of this work, therefore, is to compare recent particle size distributions of underground coal mine dust and the silica component of these dusts with estimated aerodynamic particle size distributions of calibration standard materials MIN-U-SIL 5, Berkeley 5, and SRM 1878 used by two crystalline silica analysis techniques. This work provides resolution to a previously reported discrepancy involving the proper sample dilution for the particle sizing method used. Dust impactor sampling data for various locations in 13 underground coal mines were collected between 1991 and 1998 and analyzed for the respirable mass median aerodynamic diameters. The data suggest that the MSHA P7 Method will underestimate the silica content of the sample by at most 8.5 % in the median size range of 0.9–3.6 µm and that it is unlikely one would obtain any significant error in the MSHA P7 Method analysis when the method uses Berkeley 5, MIN-U-SIL 5, or SRM 1878 as a calibration standard material. The results suggest that the NIOSH Analytical Method 7500 would be more appropriate for a dust sample that is representative of the total (no cyclone classifier) rather than the respirable airborne dust, particularly since the mass fraction in the size range below 4 µm is usually a small percentage of the total airborne dust mass. However, the NIOSH Analytical Method 7500 is likely to underestimate the silica content of an airborne respirable dust sample by only 5–10 %. The results of this study also suggest that any changes that may have occurred in the median respirable size of airborne coal mine dust are not significant enough to cause any appreciable error in the current methods used for respirable crystalline silica analysis.

Aug 3, 2005

By H. R. Shell

To obtain a better understanding of the crystallization of fluoride containing amphiboles from melts, an investigation of the range of stability between fluoramphi-boles and other minerals was conducted by the Bureau of Mines. This study has shown that the stability of fluoramphiboles is strongly influenced by both fluoride concentration and isomorphic replacement. Over 150 reactions were made with different compositions and reaction conditions. substitutions attempted and the phases that formed when the composition was crystallized by cooling from the melt are discussed. The attainment of equilibrium in these multicomponent systems is not claimed. Many ions that would be expected to enter the amphibole structure instead resulted in crystallization of phases other than amphibole. Those compositions that resulted in a high yield of acicular fluoramphibole by crystallization from the melts are shown in table 2. The fluoramphiboles obtained from melts typically had an acicular crystal habit and a hardness of 6 to 7 on the Mohs' scale. Although many had relatively high length to cross section ratios, none were fibrous; it was concluded that the possibility of synthesizing a fibrous fluoramphibole from a melt was low. However, many compositions can be crystallized into a tough, hard, impact-resistant mass of interlocking acicular crystals.

Jan 1, 1958

By Donald B. Lindsay

This report presents the findings of an investigation into the characteristics of a number of techniques for cleaning ambient air with special emphasis on their applicability to the removal of the short-lived radioactive decay products of 222-radon, the so-called " radon daughters" that have been identified with the induction of lung cancer in underground uranium miners. The purpose of the study was to review the requirements for control of radon daughter concentrations in mine air, and to examine all techniques whose feasibility has been demonstrated in principle and which in our judgment would be capable of meeting those requirements. The study has included a review of all pertinent literature, both technical and proprietary, on the subject of the control of miner exposure to the radon daughters and in the area of potentially applicable air cleaning technology. Information about the nature of the problem and about the experience of the uranium mining industry in applying air cleaning methods to its solution was obtained by visiting mines where such methods are in use, and by written correspondence and telephone conversations with other industry sources. Information on performance characteristics and costs of applicable air cleaning methods and equipment was obtained from the experience of our own engineering staff and by visits, interviews, and correspondence with manufacturers of industrial air cleaning equipment.

Jan 1, 1978

By G. Richards Gwinn

In modern warfare, mica is truly indispensable. Coordination of combatant units necessitates maintenance of intricate communications equipment, in the construction of which high-grade sheet mica is essential. Scrap, ground, and the poorer qualities of block mica, which are less essential to the military program, are not considered in this paper. Furthermore, as the paper is designed primarily to assist mica miners, mica derivatives, Such as splittings and films, also are excluded from discussion. The paper therefore relates solely to block mica of strategic quality. Understanding of t e many factor involved in marketing mica is definitely advantageous to mica, miners. The nature and detrimental effects

Jan 1, 1943

By J. H. Johnson

The report references reports and publications from 1975 to the present related to diesel underground mine air quality research undertaken by Michigan Technological University. Research results obtained on this contract are summarized in 5 different sections as follows: Section 1 - Development of a Systematic Approach to Monitoring, Data Analysis, and Interpretation for Diesel Mine Air Quality Control, Section 2 - Experimental Evaluation of LHD On-Board Air Quality Control Systems, Section 3 - Development of a Portable Self-Contained LHD Tailpipe Emissions Measurement Apparatus for NO , N0, CO, CO , and Particulate Matter, Section 4 Quantitative Analysis of Diesel and Coal particulate Matter by Laser Raman Spectro¬scopy and Section 5 - Development and Application to Detector Tubes of a Laboratory Method to Assess Accuracy of Occupational Diesel Pollutant Concentration Measurements.

Jan 1, 1985