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"Human accidents are caused by production accidents, generally ones (such as derailment of cars, falling rock, etc.) that have occurred numerous times before an employee was actually involved. Prevention of human accidents is, one of the essentials in cutting operation costs, and advocates of safety are studying economics to assist them in their work of preventing accidents.Workman's compensation insurance or compensation for human accidents is a true operating cost, and is the only purely tangible measure available which gives a measurement of the cost of accidents even though, as will be pointed out later, it represents but a portion of the total cost of human accidents.In using premiums paid for compensation insurance as a measure of the cost of accidents, it must be kept in mind that most insurance laws, as pointed out in a former paper (Serial 2590 of the Bureau of Mines) provide a waiting period before compensation for the lost-time wages starts, with the compensation limited to definite percentages of the wages. The waiting period and limited compensation combined tend to limit the amount paid to an injured workman who, if he receives 1/3 of the lost-time wage, will probably have been reimbursed as high as the average injured workman.The total or complete economic cost of human accidents, must include, in addition to compensation paid for lost time, and the portion of the lost-time wage suffered by the workman for which he is not compensated, the additional cost to the company through-(a) temporary decreased production by the breaking down of the morale, etc., (b) the breaking in of a new employee which is admittedly expensive,(c) the increased liability of human and production accidents caused to or by the new employee.Another charge against accidents, which is not included in the compensation payment, is the economic loss through the killing of as workman who has no dependents. Few of the States' laws require any compensation except burial expenses to be paid for fatalities to persons having no dependents. It is estimated by the United States Bureau of Labor Statistics that the economic loss through a fatality is 6000 shifts. If each fatality was compensated for this amount of time and at half-time wages, using an average wage of $5.00 per shift, the compensation for fatality based on the economic loss would be $15,000. but the average actual compensation paid for each fatality is about $3,000."

Jul 1, 1924

By Anthony W. Sparks

The Bureau of Mines conducted tests designed to compare its breathing metabolic simulator (BMS) with other methods that are currently used to evaluate the performance of respiratory protective equipment. The BMS is a commercially developed device that uses a piston cylinder to simulate breath movement. Using a propane furnace that consumes oxygen and forms CO2, the BMS also simulates the respiratory metabolism of humans. The breathing and metabolic subsystems of the BMS are described in detail in this report. Results are compared from tests that used the BMS to evaluate respiratory equipment and from tests that used human subjects for the same purpose. The BMS was also tested against a pulsatile breathing machine (PBM) previously designed by the Bureau. Both machines were used to test respiratory equipment, and the test results are compared in this report. To illustrate typical applications of the BMS, the report briefly describes how the BMS was used to test two different types of closed-circuit respiratory apparatus, and the test results are presented. This research showed that BMS test results compared more closely to the results of tests that used human subjects than did results obtained using the PBM.

Jan 1, 1980

By Ivette E. Torres

World investment 10 all mineral and mining industry sectors is not available. However, partial information available provides some information useful for analysis. Information available in this section covers limited geographic information on investment in the steel industry, limited information for petroleum industry capital spending, and total U.S. foreign investment in comparison to the mineral-related sectors (tables 13, 14, and 15). Annual steel industry investment is available for the European Community, almost all countries within the European Free Trade Association (EFTA), Latin America, and other countries with significant mineral industries, such as Canada, Japan, and the United States. Although information was not available for 1992, data for 1991 indicate that for those countries aforementioned, total investment increased by 8 %. However, investment patterns were very different within the different groups of countries. While the European Community had a net increase of 12 %, dominated by an almost °40 % increase in Germany, EFTA member countries had a 26 % decrease in investment for the same period. Investment in EC countries was almost seven times that of EFT A countries. Japan's investment in the iron and steel industry, by far the largest of those available, almost twice that of the EC and almost four times that of the United States, increased by more than 20 %. In North America, investment in Canada and the United States decreased. Almost all of Latin America decreased investment in the sector. The notable exception was Mexico, with a 60 % increase. Changes in Mexico's investment policies of the recent past, its economic growth, and privatization of its iron and steel industry are some of the reasons for such an increase. The other country covered individually in Latin America, where investment in the iron and steel industry increased, although slightly, was Argentina. This limited information does not allow a comprehensive analysis of global industry trend, which in turn impacts many other mineral commodities, and with the transition in many countries within Europe and Central Eurasia that are now effecting the steel industries of the countries that were members of the U.S.S.R. and its CMEA partners, it is most regrettable that comprehensive and comparable data, both current and historic, on investment in this area are not available.

Jan 1, 1994

By Bernard J. Steblay

Two instruments have been constructed that extend microseismic data collection and processing capability for Bureau of Mines research in rock burst, coal bounce and outburst, and roof fall monitoring. The first instrument is a 13-channel tape-triggering system. This system allows better utilization of instrumentation tape recorders by collecting data digitally, turning the tape on only when valid data are present, and increasing the dynamic range of the recorder by using digital data. A digital-to-analog converter is used to provide analog output of the recorded digital data. The instrument records a much larger time slice of transient events than do current commercial devices. The second instrument is a microseismic energy measurement device. This device uses recent developments In integrated circuits to overcome the dynamic range and accuracy limitations of previous instruments. The analog signal is converted to a digital one, and then high-speed multiplication techniques are used to square the amplitude value in real time and integrate it.

Jan 1, 1983

By Rolland L. Blake

Petrographic methods of examination were used by the Bureau of Mines on a suite of samples of ultramafic rock from Soapstone Ridge, Ga., located about 8 miles south-southeast of Atlanta. The samples were analyzed to determine (1) their potential for releasing regulatory particles upon crushing and grinding and (2) their concentration of fibrous particles that approach the dimensions of amphibole and serpentine asbestos minerals. Such particles might be generated during grading and excavation for housing and industrial development and could become a health concern. Light optical microscopy, scanning electron microscopy, and X-ray diffraction were the techniques used to examine the samples. Six of the twelve samples contained amphibole as a major mineral; in five, it was a moderate to minor mineral. One sample contained no amphiboles, and serpentine was not observed or identified by X-ray diffraction in any of the samples. In nine of the samples, the amphiboles exhibited a habit that was either prismatic or acicular, but not asbestiform. Two of the samples did contain asbestos, occurring as small veins or fracture fillings, which represented only a minor percentage of the total sample. Similar petrographic screening is recommended for examining any rock deposit or mine location to delineate hazardous and nonhazardous mineral areas.

Jan 1, 1982

By John T. Neubert

Between 1988 and 1990, the U.S. Bureau of Mines studied the mineral resources of San Juan National Forest to appraise and determine types and locations of deposits that could be mined economically now and in the foreseeable future. The study included a comprehensive field examination and literature search. Substantial amounts of lead, zinc, copper, gold, and silver have been mined from within the Forest in the La Plata, Rico, Silverton, and Dunton areas. At least one buried 200 million ton stockwork molybdenum deposit occurs in the Rico area. Similar size porphyry copper deposits occur at the surface and about 1,700 feet below the surface in the Bedrock Creek area of the La Plata district. Numerous smaller base-and precious-metal and uranium deposits have been prospected and mined throughout the Forest. Coal, oil, and gas have been or are currently being produced in the western and southern parts of the Forest. Carbon dioxide occurs in the western part of the Forest. Strategic elements occurring within the Forest include platinum, palladium, cadmium, gallium, indium, bismuth, and tellurium; however none of these elements is economically recoverable at present. Several geothermal areas are scattered across the eastern two-thirds of the Forest. Industrial minerals within the Forest include sand and gravel, limestone, and decorative stone.

Jan 1, 1992

By C. Melvin Lepper

Microseismic energy is generated when stresses accumulated in rock formations are released in the form of fracturing. The acoustic emissions resulting from these rock fractures and movements are detectable as velocity signals in the earth near the energy source. A Bureau of Mines microseismic system that is capable of detecting the acoustic emissions from pit slope movements is described. The digital circuitry incorporated in the system allows a microprocessor program to immediately calculate and present the location coordinates for the seismic energy source in the mine pit wall. This monitoring system is compact, portable, reliable, and relatively inexpensive and rapidly provides accurate information to the mine operators about the stability of a pit slope.

Jan 1, 1982

By William S. Roberts

As part of the Bureau of Mines critical and strategic minerals program in Alaska, 34 high-purity chromian spinel samples were analyzed for trace and major element geochemistry and mineralogy. The samples were analyzed by X-ray diffraction, X-ray fluorescence, and chemical techniques. Systematic differences in chemistry are evident when samples collected from the Chugach Mountains and their related extension are compared with chromian spinel samples collected from interior Alaska. Compared with the Chugach samples, the interior Alaska samples have higher average amounts of A1203, Fe203, Ti02, and NiO, have lower average amounts of FeO and Cr203, and exhibit greater dispersion in values. Considerable mineralogical variability of chromian spinel exists between and within individual Alaskan chromite-bearing ultramafic complexes. Of 34 samples analyzed, 25 samples are magnesiochromite, 5 are chromite, 3 are spinel, and 1 is hercynite. As a group the interior Alaska samples have a smaller average unit cell dimension than the Chugach group of samples. The chemical and mineralogical differences between the two groups of samples can be attributed to different genetic histories and may have implications for locating chromian spinel deposits amenable to standard beneficiating techniques.

Jan 1, 1985

By L. C. IlsLey, H. B. Freeman

In connection with the approval of coal-cutting machines for service in gaseous mines , the engineers of the Bureau of Mines have been somewhat concerned as to the type of trailing cables that could safely be used on permissible outfits . While no final action has been taken on this question ( tentative approvals having been granted pending investigations ) , the Bureau has been endeavoring to collect data and information on this question which would permit a fair , yet safe , ruling to be made . For this purpose cooperative arrangements were made with three coal companies to visit certain of their mines , making inspections inside the mines to observe the cables and cutting machines in operation . In all , twenty mines were visited . A questionnaire covering the operations of trailing cables was filled out at each of these mines . In a few instances no personal inspection was made , the information being supplied by mine officials after conferences with the Bureau's engineer . At other mines the information given by mine officials was supplemented by personal observation inside the mines , usually at a time when the cutting machines were in operation .

Jul 1, 1923

A series of laboratory evaluations examined the impact of water spray pressure, curtain setback distance, and external and underboom spray use for controlling respirable dust levels and sulfur hexafluoride tracer gas concentrations around a continuous mining machine. This mining machine was equipped with a flooded-bed dust scrubber and was positioned in the box or slab cut. Exhaust line brattice was used for all tests. Dust levels were measured in the return airway and at locations representing the operators of the continuous mining machine and the standard and off-standard shuttle cars. Increasing water pressure or using the underboom sprays produced no significant impacts on dust levels, although their interactions did produce some significant impacts. Increasing curtain setback distance often elevated dust levels, likely by reducing the amount of airflow reaching the face. Use of the external sprays created additional airflow around the mining machine that pushed the dust cloud past the scrubber inlets. This significantly increased dust levels at all sampling locations. Tracer gas levels were measured on the off-curtain and curtain sides of the cutter head and in the return airway. Increasing water pressure generally led to significantly increased gas levels on the curtain side, although a slight decrease was observed on the off-curtain side with the machine in the box cut. Increasing setback distance elevated gas levels on both sides of the cutter head and in the return by limiting the quantity of ventilation airflow reaching the face. Use of the external sprays provided additional airflow along the off-curtain side of the machine, significantly reducing gas levels in this region. These sprays adversely impacted the dilution and removal of gas on the curtain side of the cutter head. Use of the underboom sprays adversely impacted gas levels on both sides of the cutter head. Use of the external sprays provided the best control of respirable dust and face gas concentrations. The smaller increases in miner operator dust levels produced by these sprays were offset by larger reductions in face gas levels on the off-curtain side of the cutter head. Although the underboom sprays minimally impacted respirable dust levels, use of these sprays was not recommended because they increased face gas levels.

Jan 1, 2007

By W. H. Tomlinson

Although the thoughts and efforts of the great majority of people in many parts of the world are today directed toward killing each other, the purpose of this paper is to discuss means of conserving human life. In a world of turmoil and strife, we find time to discuss and make plans to achieve our objective -prevention of the "sacrifice" of life through avoidable accidents. The word" sacrifice" is used here advisedly, as one meaning of the word given in the 1942 edition of Funk and Wagnalls New Dictionary of the English Language is "the act of giving up some desired or valued object for the sake of *** future good." As everyone agrees that life is man's most priceless possession, one wonders if past sacrifices have been in vain. It appears that life is cheap in America; it is cheap because some of the industrialists are too much concerned with making a profit to devote much time and thought to conserving human life; it is cheap because some labor leaders apparently are interested solely in personal power and prestige; it is cheap because a great many workmen fail or refuse to cooperate energetically with the various organizations interested ill; their safety and welfare; it is of little value because, individually and collectively, we are indifferent to our responsibilities toward our fellow men.

Jan 1, 1944

By F. A. Rutledge, H. Marstraander, J. H. Hulbert, G. A. Apell

"INTRODUCTION The inability of Alaska coal mines to supply the quantity of coal required by public and private consumers and by the armed forces in Alaska caused the Coal Procurement Section of the Alaska Department, U. S. Army, to be established. It proposed to investigate the coal deposits and to expedite production of coal. The Bureau of Mines has closely cooperated in this program and was in direct charge of exploration. As to develop and equip an underground coal mine would have taken time and the need for coal was acute, a deposit that could be prepared for mining quickly was desirable. Several such deposits of stripping coal were known to occur in the Nenana field and were examined by the Bureau. One of these, the Diamond strip mine 4 miles west of Healy, was brought into production late in the fall of 1943. This mine was operated for the Army Coal Procurement Section by the C. F. Lytle Co. and the Green Construction Co.The Roth property, or Leasing Block No. 28, in the Healy Creek Valley offered the largest available tonnage of both stripping coal and total reserves. A program of exploration by the Bureau of Mines was inaugurated in 1943 and completed in 1944. Field parties of the Federal Geological Survey mapped the area had correlated the coal beds during the 1944 and 1945 summer seasons."

Nov 1, 1946

By Byron A. Baker

The Bureau of Mines used a windowed cell to measure the phase-boundary pressures of two related series of gas-condensate fluid mixtures. Normal butane was added to the mixtures incrementally to determine its effectiveness for lowering phase-boundary pressure. All the experimental data were correlated, so that the pressure required to maintain light oils mixed with natural gas in the single phase may be computed for secondary recovery applications. The heavy hydrocarbon parts of the mixtures were distillation fractions of a Gulf Coast condensate. Intermediate normal hydrocarbons in the butane-heptane range and natural gas were added to the fractions in selected proportions, so that phase-diagram pressures of 26 fluids were actually studied. The experimental range of temperatures was 50° to 280° F. Two correlations were developed to represent phase-boundary pressures by means of a polynomial. Independent variables represent natural gas content, disparity of properties of components comprising the mixtures, and temperature. A fourth variable, for one correlation only, was the quantity of normal butane added to the original mixtures. The latter correlation with four independent variables contains 15 coefficients and is estimated to be accurate to 135 psi.

Jan 1, 1973

By G. St. J. Perrott, G. W. Jones

"In cooperation with The Edison Electric Illuminating Co. of Boston, Mass., a survey was conducted in 1929 and 1930 by the United States Bureau of Mines to determine the general hazards of combustible gases and vapors in manholes and other underground openings owned by this company. The territory served approximates 650 square miles and includes 46 cities and towns. The transmission and distribution systems are on overhead construction and underground wires and cables run in underground conduits and manholes. There are 17,000 manholes on the system, and also an area in Boston proper served by the Edison tube system. These conduits and manholes are laid in various types of streets from the most modern type of cement roadbed to the older type of loose macadam. The conditions as found could be considered as typical of any public utility in the electric-light and power field. The survey extended over a period of about a year beginning in June, 1929, and ending in July, 1930, and during this time 1,765 different manholes were tested and a total of 4,068 tests were made.Previous to starting the actual survey, one of the writers, G. W. Jones, spent considerable time in Boston determining the best methods of practical· test procedure. In this work cooperation was given by John Campbell, superintendent, special service department, who for a number of years has been making a study of explosions in underground street areas and preventive measures in Boston and various cities.After this preliminary investigation the tests were continued by employees of the Edisun Company. Copies of all records of tests were forwarded to the United States Bureau of Mines Pittsburgh Experiment Station so that the writers were in close touch with the progress of the survey, and changes could be made in the test procedure whenever deemed necessary."

May 1, 1931

By Andrew B. Cecala

The U.S. Bureau of Mines has designed and evaluated total mill ventilation systems at two different mineral processing operations. Both systems have proven very effective at reducing respirable dust levels throughout the mill in a cost-effective manner. A 25,500-cfm system installed at a clay processing mill provided approximately 10 air changes per hour. This system reduced respirable dust concentrations by approximately 40 pct throughout the mill building. The second evaluation was performed at a silica sand operation. Tests were performed with 50,000 and 100,000 cfm of ventilation to the mill building, corresponding to 17 and 34 air changes per hour. Average mill-wide respirable dust reductions were 36 and 64 pct, respectively. Not only did these systems reduce respirable dust concentrations and increase visibility throughout the mills, they were also easy to install and required minimal maintenance. A total mill ventilation system provides a general purging of the mill air; the system should be viewed as a supplemental technique to assist other dust control systems in operation.

Jan 1, 2010

This report describes the development, installation and performance of a lonpwall illumination system. The longwall illumination system was installed at the Greenwich Collieries 112, Cockport, Pa. It utilized flourescent luminaires, intrinsically safe power distribution and is the first longwall system installed in Pennsylvania.

Jan 1, 1976

By W. E. Dennis, M. M. Fine

"INTRODUCTION During peacetime, the United States uses less than 3,000 tons of chemical-grade celestite annually. The war need, however, was estimated to exceed 15,000 tons a year.Hitherto; most of the required chemical-grade ore has been imported from England, Mexico, and other foreign countries. If foreign sources do not find it possible to meet the demand for ore of chemical grade (plus 92 percent SrSO4), it is expected that requirements could be satisfied by concentrating low-grade domestic ores. Celestite deposits on Brown, Nolan, Fisher, and Coke Counties, Texas, are considered to be possible sources of supply for this low-grade material. The Bureau of Mines explored the most important deposits to determine the grade and amount of ore available and conducted ore-dressing tests to obtain a suitable method of concentration.The exploratory work, consisting of test pitting and sampling, was carried on under the direction of W. E. Dennis, one of the authors of this paper, from October 8, 1942, to January 30, 1943. The ore dressing-tests described herein were conducted at the Bureau of Mines Laboratory at Rolla Mo.In this report, a particular deposit is referred to by the name of the landowner on whose .property the .deposit lies. The location of the deposits investigated is shown on figures 1, 2, 3, and 4.The celestite deposits were previously studied by the Bureau of Economic Geology of the University of Texas, and the results of its investigation are published in Mineral Survey Circular No. 46."

Feb 1, 1947

By Larry A. Haas

A major problem encountered in dump leaching operations is the plugging of both the dump and the piping by precipitated iron compounds. Bureau of Mines research to obtain basic data on agitation leaching and dump leaching methods has shown that the addition of organic chelating reagents can significantly enhance the lixiviant permeability through the ore and the concentration of the metal values in the liquor. For example, the addition of 5 giL citric acid (CA) to a conventional sulfuric acid lixiviant almost doubled the fluid flow rate through 5-cm-diameter laboratory columns containing copper ore. After 185 h of per-colation leaching, the metal concentrations with (and without, in parentheses) CA were 1.7 (1.5) giL Cu, 200 (70) ppm Mn, 160 (40) ppm AI, and 6 (3) ppm Co. The enhancement of metal concentrations with chelating reagents such as CA was confirmed by determining the solubil-ity of several metal ions as functions of pH and chelating reagent con-centration. When ferric ions became insoluble at pH values above 3, the concentrations of other ions also decreased. The addition of che-lating reagents kept iron, as well as the other dissolved metals, in solution even at pH values as high as 5. Citric acid was a more effective chelating reagent than gluconic acid, oxalic acid, or sodium lignin sulfonate.

Jan 1, 1985

By Laurance L. Oden

Titanium-enriched smelter slag produced commercially by Quebec Iron and Titanium Corp., Sorel, Quebec, was evaluated as feed material for a process developed by the Bureau of Mines to prepare rutile. Glass-forming agents including P205, B203, and two binary mixtures were added individually to the as-received and preoxidized smelter slag, and the nonferrous tramp oxides were effectively partitioned into the resulting noncrystalline phase. Iron in the ferrous oxidation state was moderately soluble in the glass of reduced specimens but less soluble under oxidizing conditions. The solubility of iron oxide in phosphate glass exceeded the solubility of iron oxide in borate glass. Effective conversion of titanium oxide to rutile was not achieved in the high-iron commercial smelter slag, and 20 to 30 pct of the titanium remained as pseudobrookite, a mixed iron-titanium oxide.

Jan 1, 1973

By William J. Campbell

The purpose of this investigation was to develop a rapid, accurate method of analysis for small amounts of calcium in wolframite concentrates. This analysis is necessary to determine if the wolframite concentrates meet United States National Stockpile Specification P-57R2, which limits the calcium content to 0.2 percent. Because of the small depth of the sample analyzed in fluorescent X-ray spectrography, the calcium Kaline intensity was a function of the chemical composition of the calcium-bearing particle as well as the total matrix composition. This particle-composition effect was particularly important in this analysis, as the calcium may be present as a carbonate, tungstate, phosphate, etc. Three methods of preparing the sample eliminated the variation of calcium Ka intensity with mineralogical occurrence: (1) Reduction in particle size by extensive grinding, (2) chemical fusion with sodium carbonate, and (3) solution of the calcium by an acid attack.

Jan 1, 1958