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By Herbert R. Babitzke

The Minerals Availability System (MAS) was formally established by the Bureau of Mines in May 1975 to provide current appraisals of the engineering and economic availability of nonfuel minerals for consideration in the formulation of both domestic and foreign minerals policy, Domes- tic mineral property reports are developed by the Bureau's four Field Operations Centers, and foreign data are obtained under contract. This site-specific information is subsequently subjected to engineering verification and economic evaluation, and the results are analyzed and published as Minerals Availability System Appraisals. The deposit-specific data are also entered into the computerized MAS data base, where a subset of this information, the Mineral Industry Location System (MILS), is available to the public in the form of computer graphics and listings. Other MAS products are also described. The Bureau's MAS personnel are frequently involved in special engineering and mineral economic projects for other Federal and State agencies. MAS personnel also work closely with the private sector, both in the area of mining and processing cost estimation, and as a source of nonproprietary mineral deposit information.

Jan 1, 1982

By John P. McDonnell

This U.S. Bureau of Mines report describes the results from an in-mine investigation of an alternative longwall gate road design. The coal mine operator modified the pillar layout (reversed the location of the big and small pillars) in a portion of a three-entry longwall gate road area. The modified pillar layout was an attempt to reduce stress and, subsequently, stress-related ground control problems (cutter roof and dynamic floor heave events) in the tailgate region during "second-panel" mining. The results from borehole pressure cells installed in the modified gate road area showed that the ground pressures in the panel edge and adjacent small pillar were significantly reduced during second-panel mining compared with ground pressures experienced in the typical pillar layout gate road areas. The reduced stress levels around the tailgate entry adjacent to the second panel, as compared with the tailgate stress levels with the typical pillar arrangement, contributed to improved tailgate ground conditions in the test pillar zone.

Jan 1, 2010

By Louis C. Brichta

The rapid depletion of known deposits of high-grade ore and the need for development of additional reserves, together with increased interest in open-pit mining of low-grade zinc-lead ores in the Tri-State District, led the Bureau of Mines to examine likely mining sites. Underground operations failed to remove all of the ore in a number of areas, and it appeared possible that some of them might be reworked successfully by low-cost open-pit methods. The South Carthage or Hull tract in Jasper County, Mo., was selected by Bureau engineers as favorable for the development of an open-pit mine.

Jan 1, 1949

By N. S. Dalal, B. Jafari, F. Y. H. Green, V. Vallyathan

"Using electron spin resonance (ESR) spectroscopy we have carried out a systematic study of the measurement of concentrations of organic free radicals in freeze-dried lung tissue. Sixty-six tissue samples were obtained from the National Coal Workers' Autopsy Study (NCWAS). The samples were characterized in terms of the concentration per gram of the free radicals, and examined in relationship to the histopathological parameters such as age, numbers of years in the mining atmosphere, the degree of disease, and smoking history. Preliminary results indicate a positive correlation between the free radicals in the lung tissue and the severity of pneumoconiosis.IntroductionThis paper summarizes our electron spin resonance (ESR) measurements of the concentration of organic free radicals in the freeze-dried lung tissue of autopsied coal miners. This work was undertaken because it is well known that most coals contain carbon-centered organic free radi¬cals,(1,2) and recent studies from our laboratories indicated that reactive free radicals might play a role in the biochemi¬cal mechanism of coal workers' pneumoconiosis (CWP) (3) Thus we obtained 144 lung-tissue samples from the Nation¬al Institute for Occupational Safety and Health (NIOSH) in Morgantown. The samples came from the data bank of the National Coal Workers' Autopsy Study (NCWAS). This selection was unique because fairly detailed histopathologi¬cal information was available for each sample.Other recent studies in this field are those of Ohta et al (4) who conducted ESR measurements on black dust deposited in autopsied human lungs, but no coal miner was included therein. Earlier Retcofsky (2) had examined one lung-tissue sample via ESR spectroscopy and had concluded that the free radicals in the lung tissue reflected simply the fusain (narrow component) ESR signals. The present study was thus undertaken to complement the earlier work (2-4) and the results indicate a positive correlation with the disease severity fairly strongly."

Mar 1, 1989

By R. H. Nafziger

Owing to the growth of alloy steel production and its influence on tramp element levels when recycled, foundries have expressed concern regarding the quality of scrap used to prepare iron castings. Reliable and current information was unavailable on the amount of tramp elements contained in iron castings over time. Accordingly, the U.S. Bureau of Mines, in cooperation with the American Foundrymen's Society (AFS), analyzed cast iron samples from participating foundries throughout the United States on a quarterly basis to ascertain possible trends. Each sample was analyzed for 28 elements to determine if changes had occurred as a function of several input variables. This bulletin describes the research and presents analytical results and evaluations over a 5-3/4-year period from January 1981 to September 1986. Results show that iron casting compositions are changing with respect to a few tramp elements such as arsenic, cobalt, chromium, tin, and zinc over the period. Changes in charge compositions probably are responsible. Significant variations between zones also were observed with aluminum, arsenic, cobalt, chromium, copper, and manganese.

Jan 1, 1990

By C. W. Smith

The U.S. Bureau of Mines; Tuscaloosa Research Center, in cooperation with the U.S. Army Corps of Engineers under interagency Agreement No. 14-09-0078-1510, conducted a comprehensive sampling program of 10 upland disposal sites along the Alabama, Black Warrior, and Tombigbee River systems in Alabama. Samples from each site were characterized according to particle size, chemical analysis, mineralogical content, and potential end use. Additionally, samples were subjected to the Toxic Characteristic Leachate Procedure to determine the presence of potentially harmful heavy metals. Based on the results of these studies, each sample was determined to have properties amenable for use as aggregate in general-purpose portland cement concretes and certain asphalt concrete applications.

Jan 1, 2010

By John C. Gagliardi

The size and complexity of modern surface haulage trucks has resulted in an increased reliance upon sensors and electronic-based instrumentation for safe and efficient operation. Design engineers need accurate information about the equipment vibration environment to efficiently and effectively build components for installation on mobile mining equipment capable of withstanding the mine environment. Examples of such components include backup alarms, communication equipment, microprocessor-based controllers, and a wide variety of sensors. Unfortunately, this information is not available to the majority of both original equipment and aftermarket equipment manufacturers. To address this problem, the U.S. Bureau of Mines performed field vibration measurements on a variety of surface mining haulage trucks. The vibration measurements were then analyzed and test specifications were developed in the form of envelopes. In conjunction with test specifications, recommendations to aid manufacturers in implementing a vibration environment test program have been included with an illustrative example.

Jan 1, 2010

By A. Tewarson

Combustibility data are presented for 14 samples representing commonly used mine materials (treated and untreated wood, conveyor belt and brattice cloth). The combustibility data were obtained in the Factory Mutual Small-Scale Combustibility Apparatus (sample area -0.008 m ). The hazards associated with the mine materials were evaluated in terms of: 1) ignition/ surface flame spread using an ignition parameter (IP). A reasonable correlation was found between IP values and U.S. Bureau of Mines ratings for conveyor belts and brattice cloth and large-scale fire test data for treated and untreated timber sets; 2) generation of combustible vapors, using a vapor generation parameter (VP); 3) heat release using a heat generation parameter (HP). A reasonable correlation was found between HP values and the large-scale fire test data for treated and untreated timber sets; 4) generation of "smoke," toxic and corrosive products using a chemical compound generation parameter (CP); and 5) light obscuration by "smoke" using the light obscuration parameter (LP). All the wood treatments, except Fireguard, were found to be effective in reducing the fire hazard. The effectiveness of the treatment appears to be due to enhancement of carbon formation in the solid phase and enhancement of water formation in the vapor phase. Concepts are presented for establishing 1) the relationship between various parameters (IP, VP, HP, CP, and LP) and basic properties of materials, and 2) the usefulness of the parameters as criteria for the combustibility and fire hazard evaluations of the mine materials.

Jan 1, 1982

By Paul Meadows

The Buckrange reservoir, Stephens field, Ark., is approaching the economic limit of production under present operating conditions. Over 100 million barrels of oil remaining in the reservoir will not be recovered by primary producing methods. The Bureau of Mines, in cooperation with the Arkansas Oil and Gas Com-mission, made the petroleum-engineering study presented in this report to aid operators in evaluating secondary-recovery possibilities in the reservoir and in planning secondary-recovery programs if their initiation is decided. The Stephens field, in Columbia, Nevada, and Ouachita Counties, Ark., is about 12 miles northeast of Magnolia, Ark., and 15 miles west of the Smackover field. Surface elevations in the area average about 240 feet above sea level.

Jan 1, 1956

By Frank E. Cash

Although during the past 10 years Alabama has attained an enviable position by its coal-mine accident experience and, like most of the other coal-mining States, has made progress in the safer operation of coal mines, there is still room for improvement, which can be realized only by still greater efforts on the part of employees and employers. From 1993, when accidents were first recorded by the Alabama State Mine Inspection Department, to 1934, inclusive, 3,451 men lost their lives in the production of 569,722,676 tons of coal. The primary purpose of this report is to bring to the attention of the mining industry in Alabama end elsewhere statistics of fatal accidents for 1931-34, with the hope that a study of the causes may lead to reduction of similar accidents in the future.

Jan 1, 1936

By James M. Link

Underground coal mining is the most hazardous industrial occupation in the United States.. Haulage accidents in underground coal mines contribute substantially to the occupational hazards of this type of work. In an effort to improve mine safety, a completely hydraulic transport system has been designed to move coal from the mine face to the preparation plant. The capital investment for the hydraulic haulage system is great, and the size of the mine developed for this study is large. Mine production for the conventional haulage mine is 1. 1 million tons of clean coal per year, while the hydraulic haulage mine will produce over 1.6 million tons of clean coal per year. Safety statistics for a number of mines of this size are shown.

Jan 1, 1975

Objective: On-the-job training (OJT) is a common means of training workers. By definition, it seems relatively simple. However, to be effective, training must go beyond the simple process of following an experienced worker around the workplace— sometimes called the "follow Joe" method. NIOSH researchers spoke with human resources personnel, safety and health specialists, supervisors, experienced miners, and new miners and found that OJT was of high interest, but was rarely part of a formal or standardized program. Various training methods have evolved to ensure that a trainee will absorb the information presented rather than simply emulate what the instructor is teaching. These methods have been brought together into a published guide for developing an effective formalized OJT program. The guide (Information Circular (IC) 9479) is called "Coaching Skills for On-the-Job Trainers." It contains materials and suggestions for your company or mine to conduct a 1-day workshop for teaching OJT trainers how to be better coaches to less experienced workers. The guide was created by the NIOSH Pittsburgh Research Laboratory and a safety professional from a private mining company.

Feb 1, 2006

By John Fitzpatrick

In this Bureau of Mines investigation a device was developed that permits the determination of the modulus of elasticity of the stress-relief cores obtained in the process of making in situ stress measurements. This determination is made by hydraulically loading the external surface of the stress-relief cores and by measuring the corresponding borehole deformation. The theoretical relationship between the borehole deformation, the applied pressure, and the modulus of elasticity is presented. Also, experimental results obtained from measurements on a simulated stress-relief core made of aluminum and on a limestone stress-relief core are given. Because of the symmetrical loading obtained with this device, the isotropy of the core material can be evaluated. With this device it is also possible to study the effect of eccentricity, that is, the effect within cores in which the inner hole is not coincident with the long axis of the specimen.

Jan 1, 1962

By Robert L. Skaggs

Sixteen nonaqueous techniques conceived to replace the current aqueous scheme for separating hafnium and zirconium tetrachlorides were re- viewed and evaluated by the Bureau of Mines. The methods are divided into two classes: separation by fractional volatilization of the tetrachlorides, which takes advantage of the higher volatility of hafnium tetrachloride; and separation by chemical techniques, based on differences in chemical behavior of the two tetrachlorides. The criteria used to evaluate separation methods were temperature, pressure, separation factor per equilibrium stage, complexity, compatibility with existing technology, and potential for continuous operation. Three processes were selected as being most promising: (1) high-pressure distillation, (2) extractive distillation from a molten salt, and (3) preferential reduction of gaseous ZrC14. Any of the proposed nonaqueous Hf-Zr separation schemes must be supplemented with additional purification to remove trace impurities.

Jan 1, 1984

By Lyman Moore

This Bureau of Mines report describes 2nd evaluates iron ore resources in California and Nevada and analyzes the California and Japanese iron ore markets in which these resources will be used. The competitive position of California-Nevada ores, in these markets, was estimated by comparing regional iron ore prices, production costs, and transportation costs with those of foreign suppliers. Resources were determined to be sufficient to produce the equivalent of 585 million tons of 64-percent iron pellets at a price of less than $15 per ton delivered at California ports. Much higher tonnage could be produced at higher prices. Iron ore requirement of the California iron and steel industry will increase to an estimated 15.9 million tons by the year 2000. A study of the iron ore production potential of California-Nevada deposits and of out-of- State sources indicated that this ore requirement can be supplied most economically by California-Nevada ores. Iron ore import requirements of the Japanese iron and steel industry will increase to an estimated 150.0 million tons by the year 2000. A study of price trends in this market indicated that very little California-Nevada iron ore will be sold in Japan after 1973 when existing sales contracts expire. Iron ore-exports might be economically possible if ore could be transported from California to Japan at ballast rates as backhaul on existing petroleum shipping.

Jan 1, 1971

By Frank J. Wiebelt

Under a general program to extend the resources of mineral deposits, the Bureau of Mines examined the Quien Sabe antimony mine in October 1948. The preliminary evaluation demonstrated that a diamond-drill program was warranted co establish the tenor and persistence of the veins and permit an estimation of antimony reserves. The Bureau of Mines conducted a diamond-drilling program on the property from December 1949 to May 1950. Ten holes aggregating 2,483 feet were drilled. Nine of the holes encountered antimony-bearing vein material.

Jan 1, 1956

By P. L. Woolf, N. Bernstein, M. M. Fine

Continuous experimentation utilizing a 3- by 36 - foot rotary kiln was conducted to demonstrate the feasibility of simultaneous induration and reduction of magnetic taconite concentrate . Lignite , or lignite - anthracite mixtures , and green magnetite pellets (64.2 percent Fe , dry basis ) were heated in a rotary kiln to about 2,100 ° F. After separation from excess reductant , the product pellets were found to be highly reduced and acceptably hard . A total of 140 tons of prereduced pellets with an average Fe content of 79.0 percent was produced at Minneapolis and smelted in the Bureau's experimental blast furnace at Bruceton , Pa . Two additional supplies of prereduced pellets were obtained from The Steel Company of Canada , Ltd. , Hamilton , Ontario , which contained 83.8 and 91.3 percent Fe , respectively . Smelting of prereduced pellets was compared with that of unreduced pellets obtained from The Hilton Mines , Shawville , Quebec , and from the Erie Mining Co. , Hoyt Lakes , Minn . Blast furnace tests established that a substantial decrease in coke rates and higher production result from the use of prereduced pellets .

Jan 1, 1964

By Seth T. Reese

REPORTS received from operating companies by the Bureau of Mines, United States Department of the Interior, indicated marked progress in the reduction of injuries to employees in the coking industry in 1951 as compared with 1950. The fatality rate (0.14) per million man-hours of exposure declined 33 percent and was the second best performance since statistics on the industry were first collected in 1916. The nonfatal-injury rate (10.94), the best since 1940, declined 8 percent and was bettered only in 8 of the past 36 years. The nonfatal rate is based on all injuries resulting in loss of time for more than the remainder of the day on which the injury occurred. The exposure to hazard, as represented by the number of man-hours of work time during the year, was 7 percent higher than in 1950 and, except for the year 1943, was the highest since 1920. The fatality rate for men employed at beehive-coke ovens decreased 16 percent and the nonfatal-injury rate 23 percent, while the man-hours of work time or exposure increased slightly over 16 percent. The fatality and nonfatal-injury rates at byproduct ovens declined 33 and 2 ½ percent, respectively, while the number of man-hours worked increased 6 percent.

Jan 1, 1954

By S. H. Ash

THIS REPORT covers the third in a series of five projects into which the Conowingo tunnel system has been divided for geographical and practical reasons. It outlines the work constituting Project No.3 that consists principally of the following: (a) To sink the No. 15 shaft and extend the Alden, Sugar Notch, Baltimore No.2, and Laflin shafts from their present depths to tunnel level; (b) to drive a tunnel off these shafts to connect with the western end of the tunnel in Project No.1 (Lackawanna) and to a point 1 mile south of the No. 15 shaft; (c) to construct an emergency pumping plant at the No. 15 shaft, complete with 3 centrifugal pumps of 200-cubic-foot-per-second (c. f. s.) capacity each, and a discharge-water shaft and a discharge tunnel for conducting the water from the pumping plant into the Susquehanna River; and (d) to construct a lateral tunnel 1 mile long off the main tunnel in the vicinity of the No. 15 shaft, to be known as the Wyoming lateral. The project, as outlined, is a self-contained drainage unit that will permit unwatering inundated mines and safeguarding active mines in the Wyoming Basin of the Northern field and also will handle the water in the Lackawanna Basin, thus permitting the temporary pumping plant provided in Project No.1 to be discontinued. The pumps installed in the temporary pumping plant provided in Project No.1 can then be moved to the emergency pumping plants recommended in Projects Nos. 2 and 3, to be installed as the third or standby unit.

Jan 1, 1955

By Wilbert J. Huff

The organization of the'Explosives Division is indicated by the accompanying chart (fig. 1). As this has been discussed in a previous report3/, it will not be considered further in this report. The activities of the various units are outlined below. I. INFLAMMABILITY OF GASES AND VAPORS4/ Determination of the Explosion Hazards of Combustible Gases and Vapors Found in Mines and Industries The Explosives Division maintains, at the Pittsburgh Experiment Station, a laboratory specially equipped for the determination of the explosion hazards of combustible gases and vapors. Of particular importance, is the determination of the chemical composition within which explosions may occur and beyond which there is no danger of explosion, combustion or inflammation. These limits, known as the limits of inflammability, as determined by this and other laboratories, have been compiled in Bulletin 279 of this Bureau. The last revised edition (1931) of this bulletin has been exhausted. Since it was published, the Pittsburgh laboratory has determined the limits of about 40 combustibles and has ascertained more precisely and accurately many previously published limits.

Jan 1, 1938