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By O. C. Blade

This report is one of a series made by the Bureau of Mines under a cooperative agreement with the American Petroleum Institute on the characteristics of commercial aviation gasolines. The series of Surveys is a continuation of like work conducted under aimil.ar cooperative agreements with the Coordinating Research Council, Inc. by the National. Bureau of Standards from 1940 through 1946 and by the Bureau of Mines from 1947 through 1949. A completed list of the series of surveys is given at the end of this paper.

Jan 1, 1951

By David Schlain, C. B. Kenahan, F. X. McCawley

The electrodeposition of protective coatings of tungsten from a sodium and lithium borate - tungstate - tungstic oxide fused salt electrolyte was investigated . Soluble tungsten anodes were employed . Deposits were made on molybdenum , Carpenter 20 stainless steel , Inconel , and nickel . An atmosphere of argon was maintained around the electrolytic cell , and the electrolyte was stirred by rotating the cathode . Thick deposits of tungsten (up to 26 mils ) were made at a temperature of 900 ° C and cathode current densities of 0.3 to 0.4 ampere per square inch with high current efficiencies . The effects of variations in temperature , current density , electrolyte agitation , and tungstic oxide content of the electrolyte and of the presence of impurities such as moisture , air , iron , and nickel were investigated .

Jan 1, 1964

By J. L. Holman

The Bureau of Mines is conducting research to recover strategic and critical metals such as Ni, Co, and Cr from mixed contaminated super-alloy scrap. One approach being studied involves melt refining of superalloy scrap to produce anodes for electrolytic deposition of Ni-Co alloy. This melt refining of superalloy turnings is described based on melt-oxidation and oxidation-carburization experiments, using roasted superalloy grinding sludge to supply the 0 needed to oxidize Cr and other readily oxidized elements to the slag. Controlled melt-carburization subsequent to oxidation improved the metal phase recovery of Ni and Co to well over 90 pct and decreased electrolytic solubility of Cr, Mo, and W by carbide formation. Electrolytic refining experiments were conducted using a controlled-potential mode (preset cathode potential). Data show effects of Fe and Cr impurities, cation concentration, electrolyte pH, S04-Cl electrolyte ratio, temperature, cathode potential, and cation-selective membrane use on current efficiency, current density, and deposit composition. Disposition of Ni, Co, Cr, MO, W, and Fe is compared for melt-oxidized versus oxidized-plus-carburized anodes. Deposits containing >97 pct Ni + Co (major impurity Fe) have been routinely obtained from scrap anodes. Research is continuing to improve deposit quality in sustained deposition and to recover Cr and other metals from refining slags and anode sludges.

Jan 1, 1986

By Gerald T. Homce, Michael R. Yenchek, H. Kenneth Sacks, James C. Cawley

Accidents occur when least expected, from sources that we rarely anticipate and with outcomes that can vary greatly. Anyone who has ever been involved in an automobile accident knows, the transition from driving comfortably and safely down a highway to being involved in a potentially life-threatening situation can occur in a heartbeat. Accidents on the job are no different. The mining industry has a relatively small number of electrical injuries, compared to industries such as construction or agriculture, due to the small total employment in mining. Mining does, however, have one of the highest occupational electrocution rates of any U.S. industry, at 2.8 for every 100,000 workers per year. This is approximately four times the average for all industries. Data from the Mine Safety and Health Administration (MSHA) shows that 75 electrical fatalities occurred in the mining industry between 1990 and 1999. Of these, at least 17% involved high-reaching mobile equipment that contacted overhead power lines.

By Louis A. Panek

The practice of roof bolting, now recognized as an effective method of support, is based largely on rule of thumb. Among the various applications of bolting, the support of stratified mine roof is by far the most common. The general principles relating to this type of reinforcement are presented in two companion reports; the first describes the function of the bolts, the bolting pattern, and the behavior of bolted roof (1), 2/ and the second describes the design of the models and the theory of the experimental method (2). This report presents a rational method for designing systems of vertical bolts to reinforce horizontally bedded mine roof, developed from model tests. The structure treated herein may be described as follows: The immediate roof, consisting of beds of like material and equal thickness with no bond between them, is reinforced by vertical bolts installed in straight lines across the opening; the case of suspension is excluded because the bolts are assumed not to extend above the immediate roof. The assumption is made that the behavior of the lowest bed approximates that of a rectangular plate clamped along two opposite sides (the ribs). These specifications represent approximately the roof conditions encountered in mining bedded deposits of all kinds - coal, potash, iron ore, etc. Thus, for the design of a roof-bolting system a quantitative solution to the following problem is required: For a roof composed of beds of given thickness and physical properties, how does the support depend upon the length, spacing, and tightness of the bolts?

Jan 1, 1956

By Erle C. Donaldson

The pendant drop interfacial tensiometer is being used to study interfacial phenomena that influence the production of crude oil. A description of the instrument showing the modification of the cell and cell holder is presented. The modified cell and cell holder allow formation of a precise and reproducible drop size, and the image of the drop is easily alined and focused. Interfacial tension measurements and observations of film formation can be conducted at various temperatures with the jacketed cell.

Jan 1, 1967

By John A. Johnson

Conclusions regarding the use or omission of stemming in blasting have not peen reached, pending completion of all aspects of this investigation. The results from the dust phase of this study on six classes of stemming prove that the kind of stemming affects the amount of dust produced from blasting. In previous work at the Mount Weather testing adit it was demonstrated that blasting produces the highest dust concentrations of any of the mining processes.5/ Under the conditions prevailing at the Mount Weather testing adit, the average of all rounds having a break of at least 95 percent showed that the least amount of dust was produced when no stemming was used.

Jan 1, 1940

By M. M. Tilman

As part of ongoing research to improve mine safety, the Bureau of Mines conducted research on the corrosion of friction rock stabilizer steels in five Missouri lead and iron mine waters. Electrochemical corrosion tests, including evaluation of pitting tendency, were performed on two types of high-strength, low-alloy (HSLA) steels and galvanized steel in four Missouri lead mine waters and one Missouri iron mine water. The tests were conducted at in-mine water temperatures in both air-saturated and deaerated waters. Static, weight-loss corrosion tests were also conducted on HSLA steel specimens in the five Missouri mine waters for 2,900-h duration at average in-mine water temperatures and air-dissolved oxygen contents of 6 to 7 ppm. Corrosion rates determined by the weight-loss tests were roughly comparable with rates determined electrochemically in deaerated waters containing 0.3 to 0.5 ppm dissolved oxygen content. Passivation of specimen (nongalvanized) surfaces in air-saturated waters resulted in very low electrochemically deter- mined corrosion rates. Pitting-tendency was generally higher for both HSLA steels in air-saturated waters than in deaerated waters. Galvanized steel generally exhibited higher tendency to pitting in the deaerated waters than in the aerated mine waters.

Jan 1, 1985

By Shail J. Butani

In 1986 the Bureau of Mines conducted a probability sample survey, Mining Industry Population Survey, to measure such employee characteristics as occupation; principal equipment operated; work location at the mine; present job, present company, and total mining experience; job-related training during the last 2 years; age; sex; race; and education. The population estimates are necessary to properly analyze the Mine Safety and Health Administration (MSHA) injury (includes illness and fatality data) statistics; that is, to compare and contrast injury rates for various subpopulations in order to identify those groups that are exhibiting higher than average injury rates. This report uses the survey's results to characterize the U.S. nonmetallic mining workforce from March through September 1986. Similar reports have been prepared for the metallic, stone, and sand and gravel mining industries, as well as for the entire metal and nonmetal mining (includes metallic, stone, sand and gravel, and nonmetallic industries) sector and the cool mining sector.

Jan 1, 1988

By Robert H. Merrill

This Bureau of Mines report summarizes the design and tests of a gage that will simultaneously measure the deformation of a borehole along three diameters 60 degrees apart; the measurements are in a single plane normal to the axis of the borehole. The inherent errors in measurement are considered together with the problems associated with the use of the gage in the relatively severe environments in and around mine openings. These problems were treated in the design and tests of the gage and the results establish that the gage can be used to satisfactorily is determine estimates of the stresses in rock.

Jan 1, 1967

This Bureau of Mines publication consists of an overview of the mine waste management research currently being conducted by the Bureau. The following papers, given at a Technology Transfer Workshop, emphasize the increasing importance of research related to the safety and environmental considerations of mine waste disposal In recent years. Current work related to legislation passed in the last 10 years and their subsequent standards includes the development of adequate monitoring systems, development of stability and seepage prediction and control techniques, control of runoff water, and control of leaching solutions. Selected topics are included here that cover coal mine waste disposal, embankment slope stability monitoring, flow failures of mine tailings impoundments, and controlled burnout of abandoned coal mine fires. The projects described provide a current documentation of problems being addressed.

Jan 1, 1981

By George H. Popper

The Bureau of Mines has evaluated the extent of phosphate resources available for recovery by the experimental borehole mining method in the Southeastern Coastal Plain of the United States- Phosphate re- sources at overburden depths greater than 30 m are as a rule currently unsuitable for recovery through conventional mining methods because of economic, environmental, or technical considerations. In the identified deposit areas, borehole mining operations are projected to yield a more favorable rate of return and to be environmentally more desirable than conventional surface mining. Borehole mining resource estimates presented in this study are preliminary and designed to serve as a basis for future resource evaluations, as the current data base is relatively sparse and incomplete. The resulting resources have, therefore, been classified as hypothetical and speculative and are subject to up- dating as additional exploratory data become available. Hypothetical and speculative resources amenable to borehole mining are estimated to total about 385 billion metric tons (rat) of phosphate matrix with a minimum in situ grade of 5 pct P205. With projected borehole mining capabilities and current conventional beneficiation procedures, this resource would make available approximately 64 billion mt of phosphate rock product at an estimated grade of 30 pct P205.

Jan 1, 1985

By F. S. Crawford

Although it may be impracticable to adopt standard methods of safe working in all branches of mining, and although it may be impossible to establish a standard for each class of work at each mine, some of the iron-mining companies in the Lake Superior district have found that by adopting certain standard ways of performing certain of their operations they insure both more efficient and safer working conditions. Many companies have adopted the idea that the safe way of doing things is also the most efficient and economical way, and, through the medium of their safety conferences they are trying to find the safest way, and the most efficient way, of performing practically every operation about the mines. This activity will, undoubtedly, be continued at every operation which uses this method of doing safety work, because in the advance of industry changes must be made in the results required from time to time. A review of the safety standards and safety suggestions which have been arrived at by some of the companies in this the greatest iron-mining district in the world, will be of value to companies who are interested in improving the safety of their working conditions. So that attention may be directed to the methods in use, rather than to individual companies, all names have been omitted and companies are referred to only by letter.

Aug 1, 1931

By N. S. Dalal, X. Shi

"This study reports a new property of the important NAD(P)H-dependent flavoenzymes, glutathione reductase, lipoyl dehydrogenase and ferredoxin- NADP oxidoreductase, that can catalyze a one electron reduction of metal ions such as chromium(VI) and vanadium(V). During the enzymatic reduction process, molecular oxygen is reduced to H2O 2 , which reacts with the reduced metal complexes to generate hydroxyl radicals. Since the hydroxyl radicals have been suggested to play an important role in Cr(VI) toxicity, this study provides a basis for a recent observation that Cr(VI) mutagenesis is strongly oxygen dependent. These results also point to an enzymatic pathway for the metabolism of some metal ions and concomitant generation of hydroxyl radicals. l. INTRODUCTIONThe purpose of this communication is to report that some important NAD(P)H-dependent flavoenzymes (glutathione reductase, lipoyl dehydrogenase and ferredoxin-NADP+ oxidoreductase) can catalyze one electron reduction of metal ions such as chromium(VI) and vanadium(V) and simultaneously reduce molecular oxygen to generate Hi02 and, eventually, the ""OH radical. This finding is significant because (i) the known substrates for the flavoenzymes are organic species and not metal ions, and (ii) the report on the enzymatic formation of the ""OH radical provides a new pathway for understanding the mechanism of genotoxicity of some non-ferrous metal ions. For example, it has been suggested that OH radical is likely to be the major species responsible for Cr(VI) genotoxicity [1-5). The 'OH radical is generated through the reaction of Cr(V) complexes with cellular Hi02 [4,5]. Cr(V) itself is known to be generated from Cr(VI) in various biological systems, in particular, microsomes [ 6), mitochondria [7] and mitochondrial electron transfer chain complexes [8]. However, no specific enzyme responsible for the Cr(V) generation has been identified except possibly glutathione reductase [4]. In this study we have used ESR and spin trapping techniques to show that the flavoenzymes can generate Cr(V) and provide a catalytic redox cycle for 'OH formation in such reactions. Herein we present our results on Cr(VI) and summarize those on other systems. Correspondence address: N.S."

Jan 1, 1990

By John A. Johnson

Conclusions regarding the use or omission of stemming in blasting have not peen reached, pending completion of all aspects of this investigation. The results from the dust phase of this study on six classes of stemming prove that the kind of stemming affects the amount of dust produced from blasting. In previous work at the Mount Weather testing adit it was demonstrated that blasting produces the highest dust concentrations of any of the mining processes.5/ Under the conditions prevailing at the Mount Weather testing adit, the average of all rounds having a break of at least 95 percent showed that the least amount of dust was produced when no stemming was used.

Jan 1, 1940

By Oleg Terichow

Electrophoretic mobility measurements were made by the Bureau of Mines on samples of a Florida phosphate slime to determine the optimum conditions of coagulation and settling in an aluminum sulfate solution. Addition of anthracite to promote mutual coagulation demonstrated the practicability of heterocoagulation by reduction of the repulsive effect of double layers. By proper selection of the electrolyte and its concentration, the reduction of the double layers to a net zero point of charge causes the predominance of Van der Waals' forces of attraction leading to the coagulation and rapid settling of both particle systems, as is predicted by the Derjaguin-Landau-Verwey-Overbeek theory of colloidal stability. Confirmation was found in the microfiltration tests where a modified Carman equation was applied to evaluate the specific filter bed resistance.

Jan 1, 1975

By W. C. Phalan

"Prewar Conditions:Metallic magnesium may be considered a war metal, but a war metal with a future, so far as the industry in the United States is concerned. Its production in the United States prior to 1915, on a commercial scale, was negligible, but imports prior to that year may be taken as a gaze of the demand for the metal. Unfortunately, magnesium was not listed separately by the Department of Commerce prior to the war, among the importations, but was included with other metals, as follows: ""Barium, calcium, magnesium, sodium, and potassium, and alloys of which said metals are the component materials of chief value."" However, the imports of metals enumerated other than magnesium were probably small, so that the importations under the above caption may be considered chiefly metallic magnesium in one form or another and, therefore, is an approximate gage of the demand for the metal in the United States. These imports were as follows:These figures are so close that they give a good idea of the figures for the respective calendar years.Of this prewar use, it has been estimated that about 85 per cent was used annually and in approximately equal quantities in the production of (1) flash-light powder, (2) fire works, (3) aluminum casting work, and (4) nickel and nickel-copper alleys, such as monel metal, etc. The re¬maining 15 per cent was employed for general uses, such as deoxiding brass and other copper alloys in foundry work, and to a small extent in laboratory and research work."

May 1, 1920

By J. K. Whyatt

Assuring ground control safety in many mining and tunneling projects depends, at least in part, on an understanding of in situ stress conditions that will be encountered. Yet it is rarely practical to conduct more than a very limited number of stress measurements. Stresses along the route of a proposed excavation are typically interpolated from available measurements, often assuming a linear variation of stress with depth (or elevation). However, projects where multiple stress measurements are conducted often report more complex variations of in situ stress, usually in apparent relationship to geologic structures. These structures often include lithologies of contrasting elastic properties. A method is proposed for estimating stresses in these cases by first back-calculating regional loads from available stress measurements and then modeling the distribution of stress throughout the rock mass. The method has been successfully applied to a set of in situ stress measurements from the Coeur d’Alene Mining District of northern Idaho, USA. Results provided new insights into district stress conditions and the distribution of rockburst hazards along mine drifts and between various mines. This success should transfer readily to suitable deep tunneling projects.

By Richard F. Link

A statistical technique, useful to analyze assay and other data characterized by location in three dimensions, is described in this Bureau of Mines report. If present, trends in the data are defined for the purposes of improving ore estimation, predicting ore beyond existing workings, and aiding geological interpretation. The technique is to fit linear and quadratic polynomial equations to the data through the statistical method of regression analysis. The fitted linear equations have the geometric form of hyperplanes; the fitted quadratic equations have the geometric form of ellipsoids or elliptic hyperboloids of one or two sheets. To visualize these three-dimensional forms, contour maps of a series of plane sections through the fitted surfaces are plotted. Both the fitting of the polynomial equations and the plotting of the con-tour maps are done by electronic computer to facilitate calculations and to obtain accurate results. Computer programs are described in appendixes. Methods employed are illustrated by an example analysis) based on data from a part of the Fresnillo mine) Zacatecas, Mexico.

Jan 1, 1966

By John C. Machisak

Employment and related injury experience of the coking industry in the United States for 1956 contained in this publication is summarized under three general sections: (A) General injury experience: Tables 1 to 9: Current and comparable statistics on operating data, number, frequency, and degree of severity of injuries and major accident agencies involved in the cause of injuries. Data are presented for the industry as a whole, for each type of oven, and for the States in which coke was produced. (B) Selected injury experience: Tables 10 to 15: Comparable injury data covering 5- and 10- year periods on the number and degree of severity of injuries and major accident causes.

Jan 1, 1958