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By E. L. Singleton

The electrochemical reduction of aluminum chloride to aluminum was investigated in a closed, two-compartment cell utilizing a molten chloride electrolyte. The externally heated cell was divided into a reduction compartment and a combination AICl3 feed and metal removal compartment. Aluminum was deposited at 700° C on a molten aluminum catbode from a KCI-NaCI-AICI3 electrolyte. The AICl3 content of the electrolyte was replenished by either vapor or solid additions. The chlorine evolved was collected and measured to give a quantitative evaluation of AICl3 reduction. The effects of anode and cathode current densities and AIC13 concentration on anode current efficiencies were studiedo A range of 64 to 84 percent anode current efficiency was obtained with the 25-pound electrolyte capacity cell and related auxiliary equipment.

Jan 1, 1968

By A. L. Murray, C. A. Allen

"In the Spring of 1919, the Industrial Commission of Utah undertook the assembling of safety orders covering metal mining operations Just at that time there appeared several articles in the mining papers advocating the licensing of hoisting engineers, so this subject was given careful consideration,The licensing of hoisting engineers means that they must pass an examination covering the mechanical features of hoists and boilers, and must have a certain amount of experience. This undoubtedly serves to get a class of hoisting engineers that are better informed about the mechanical operation and theoretical considerations in hoisting and the only room for argument against it is that it is difficult to give an examination that will determine whether or not a man is a competent hoisting engineer.A man might pass an excellent examination yet be absolutely unqualified to operate a hoist and the judgment of the mine super- intelligent would have to be depended upon to choose the right man from among those who were licensed. This difficulty of properly determining, by ordinary examination, a man's qualifications to run a hoist caused the idea of licensing' in the ordinary sense of the word to be abandoned; but, as there was no question that a hoisting engineer should be physically fit, it was decided to require a medical examination, and at the same time to require the hoist engineer to state his experience, so the State would better knowledge of his general qualifications.The orders covering the question were therefore issued as follows;"

Jan 1, 1920

By P. R. Perry

This publication is a compilation of tested methods for the analyses of titanium tetrachloride, titanium sponge, and various intermediate materials and products. They are presented in concise form without the detail usually found in publication of new methods because many of them are modifications of well known procedures. The Electrometallurgical Experiment Station, Boulder City, Nev., has been developing titanium production methods since 1945. Most of this development was on a modified Kroll Process but also included work on sodium reduction and electrolytic methods. During these years a large variety of samples were analyzed. Most of the analytical problems were solved using published methods or modifications of the same. At the start, there were no published procedures for analyzing titanium sponge using spectrochemical methods. A great deal of study was given to testing several of the well known techniques, and some of them, such as direct sparking of the metal, proved to be completely unsatisfactory. Solution-spark techniques were finally tried, and satisfactory procedures were developed for some of the more common impurities. These spectrochemical methods were then put into routine use for several months before their publication.2/ Some new modifications have been made, and techniques have been developed to determine other impurities found in titanium sponge and tetrachloride. All spectrochemical methods used in 1954 are included in this publication.

Jan 1, 1955

By Edward W. Parsons

To determine in what part and to what extent creep or movement exists in an installed rock-bolt anchor and the effect of the creep or bleedoff on the tension load on a rock bolt, as well as the effect of normal mining activity on the rock-bolt load and anchor, the Bureau of Mines conducted tests in the laboratory and in two mines using four types of expansion-shell anchors, the wedge bolt, and in one mine, explosive-anchored rock bolts. Specially mounted heavy-duty springs, calibrated to obtain load readings from spring movement, were installed on the test bolts to prevent a drastic reduction in tension load caused by slipping or seating of the anchor. A dial gage, reading to 0.0001 inch, measured movement of the anchor shell against the rock and seating of the anchor wedge plug in the shell. While all bolts had electrical resistance strain gages for load reading, only readings from the laboratory tests were used because those from the field tests were erratic. The tests revealed that most load loss resulting from static loading is due to the slippage and seating of the serrations on the anchor shell into the drill-hole wall. Dynamic loading, primarily from sudden shocks from nearby blasting, and possibly from ground movement or mining activity, will cause the anchor wedge plug to seat in the anchor shell.

Jan 1, 1969

By K. L. Paciorek

The aim of the present study is to determine on a gram per gram basis the toxic products of the thermal oxidative degradations of selected compositions. Four families of materials were investigated under the subject contract namely polyvinyl chloride and neoprene compositions, rigid urethane foams I and woods. Three methods were employed to conduct the thermal oxidative degradations: a sealed system (quiescent environment) I a stagnation burner arrangement (dynamic environment) I and a flow-through apparatus (dynamic I but less severe than stagnation burner conditions). The majority of tests were conducted using the first two systems; only limited experiments were carried out employing the third decomposition procedure. All decomposition was done at temperatures of 370 -4000C I the higher temperature being used in the stagnation burner. It has to be stressed that the nature of the products and the relative product concentration are temperature dependent. Thermogravimetric and differential thermal analyses were performed to supplement and extend the above delineated studies and to explore the feasibility of using these analyses as a method for material differentiation.

Jan 1, 1973

By Andrew M. Leszcykowski

This report represents the first comprehensive accounting of lode mining sites in the Sheep Mountain mining district, Custer County, Idaho. Twenty-one mine and prospect locations have been added to the Bureau's Mineral Industry Location Subsystem (MILS) data base as a result of initial phases of a mineral appraisal of the River of No Return Wilderness; previously known locations were checked and the updated information added to the data base. The district's deposits are mainly confined to metasedimentary xenoliths in granodiorite and quartz monzonite. Those deposits in the north and west parts of the district are lead-silver-zinc replacement veins in dominantly calcareous facies; those in the southern part of the district are polymetallic fissure-veins containing pyrite, chalcopyrite, arsenopyrite, galena, and sphalerite hosted by micaceous schist and phyllite. The dominant structural trend in the southern part of the district is northwesterly and on strike with major deposits in the adjacent Seafoam mining district.

Jan 1, 1983

By A. F. Baker

Tests were conducted in commercial foundries to determine the suitability of calcined anthracite as a cupola fuel. The calcined anthracite performed satisfactorily at two of the three foundries where iron-melting tests were conducted. Performance at the third installation was unsatisfactory because metal temperatures deviated widely and, in general, were lower than is desirable for the type of castings being made.

Jan 1, 1963

The works recorded in this Test Report have been performed by Rade Roncar - Electrotechnical Institute of Zagreb, SFR Yugoslavia in collaboration with Bureau of Mines. The main objective of these investigations was to investigate the possibility of fabrication of thin-walled square enclosures of satisfactory safety factor in accordance with requirements of effective technical regulations. The results and the investigations can be divided in three main fields: - investigations of thin-walled enclosures with the view of determination of pressures causing technological deformations before performing tests in accordance with effective applicable regulations, - finding the safety factor by means of tests of metal-foam pressure vents, - comparison of enclosures with and without pretreatment by technological deformation.

Jan 1, 1987

In this U.S. Bureau of Mines report, two drill-split mechanical excavation mining system concepts are described, casted, and cost compared with conventional drill-blast mining systems. The concepts for the two drill-split mechanical excavation mining systems presented are (1) a method for steeply dipping narrow veins 0.6 to 1.2 m wide and (2) a longwall method for fiat-lying tabular ores. In the proposed systems, 70 to 80 pet of the ore is disposed of underground as backfill. For sortable ores, face area crushing, sorting, and direct stowage of run-of-mine waste and low-grade ores are proposed. The underground sorting and stowing of waste reduce materials handling, processing, and waste disposal costs by reducing the quality of ore transported to the surface by 70 to 80 pet (by volume). Because many of the tools and techniques proposed for use in these systems have little or no historical mining industry use, cost assignations are heavily influenced by engineering judgments and presented as prefeasibility-level cost estimates. These estimates, presented as discounted-cash-flow-rate-of-return (DCFROR) values, show the proposed systems to be at least as profitable as, and in some cases 50 pet more profitable than, conventional drill-blast mining.

Jan 1, 1994

By Stephen H. E. Phillips

This report outlines the modifications that have been carried out to the original prototype rectangular shaft sinking equipment for its use in a circular shaft. The surface testing of the machine is described where seven, 24 ft. diameter shafts were excavated to an average depth of 21 ft. at rates ranging between 1 ft/hr and 1.9 ft/hr depending upon the prevailing conditions. The durability and productivity standards for the equipment were established indicating that the objectives of the project had been realized. That is, when using the machine the sinking rates could be increased by 25% and costs reduced by a corresponding amount compared with conventional drill and blast methods. In addition it was shown that the machine had been developed to a state of fitness for sustained underground use.

Jan 1, 1981

By Robert Stefanko

The following tables contain the average, maximum and minimum power parameter levels for several mining machines. Power factor is listed only for defined transducer output regions. The reasons for the undefined areas are provided in the Instrumentation Chapter. Several maximum voltage drops are included, and are computed from the no load line-to-line voltage: Again, the drops are from measurements at the low side of the load center. The machines are: Continuous Miners; F6A Alpine 76AM Jeffrey (d-c) 8CM Joy 8CM (10CM) Joy 9CM-2AH Joy loam Joy CU-43-2H Joy 2 each CM26H Lee-Norse CM28E Lee-Norse Shuttle Cars; 18SC Joy 48S Torkar (a-c) 2 - 10SC Joys input to rectifier 2 - 16SC Joys input to rectifier

Jan 1, 1973

By R. F. Abernethy

Recent investigations in the United States and in other countries have produced considerable information on the nature and occurrence of minor elements in coal. The possibility of recovering certain elements, particularly germanium and uranium, from coal ash and other coal products has received considerable attention. Some flue dusts are potential sources of germanium, and certain lignite deposits are potential sources of uranium, but industrial recovery of these elements has been limited to small quantities for technical and economic reasons. Considering the large amount of coal mined annually, a small percentage of a rare element may have industrial significance if an economical method of recovery can be developed. In 1944 information on the occurrence of rare elements in coal was reviewed in Bureau of Mines Technical Paper 669 (46).3 This report is a revision of that paper with the view of summarizing published information available for United States coals, and pertinent information concerning coals of other countries. Selected references from the original paper are retained. New references do not include all preliminary reports when more permanent literature describing complete projects is available. Consequently, the list of references should not be considered complete.

Jan 1, 1963

By J. Tomlinson

Shuttle car trailing cable splices were tested for resistance to failure upon being subjected to repeated bending, abrasion, and tensile shocks using a new testing method that closely simulates shuttle car induced stress. The results show that under normal stresses, splices can be made to withstand the equivalent of three months of operational use. Restoring the tensile strength to the conductors is found to be as critical as restoring flexibility. Splices in which the conductors are of slightly unequal length did not present as serious a workmanship problem as previously thought since test results show that the conductors tend to equalize when longer cables, in contrast to short cables employed in previous testing methods, were used. Dynamic recordings of cable tensile stresses are presented for a shuttle car and the new simulated testing method. Two simple but effective methods for removing insulation using a knife and a pair of pliers are described. None of the designs tested for a sacrificial splice covering were satisfactory.

Jan 1, 1979

By David A. Lipton

U.S. Bureau of Mines personnel examined mines, prospects, and mineralized areas to determine the mineral resources and potential of the Moses and Dennison Peak RARE II areas in Tulare County, California. These areas, along the west slope of the Sierra Nevada, are underlain by grarnitic rocks of the Sierra Nevada batholith and contain numerous metasedimentary roof pendants. Silver, copper, and zinc occur in contact-metasomatic deposits within the metasedimentary rocks. In the Moses area, the Powell Mine (fig. 1) contains an estimated 90,000 tons (82,000 t) of subeconomic silver, zinc, and copper resources. The King Solomon Prospect has 3,000 tons (2,700 t) of silicified phyllite containing zinc. On the Helen-Joyce Prospect, 44,000 tons (40,000 t) of gossan occur above a poorly exposed silver-zinc rich zone. Potential exists for additional mineral resources and occurrences at each of these properties.

Jan 1, 1983

By Frank E. Chase, John L. Ellenberger, Christopher Mark

The nature of competition in the coal market tends to deplete the most favorable coal reserves first, and forces subsequent development of mines in more extreme ground conditions such as those associated with multiple-seam mining. In fact, 70% of the United States coal reserves are in multiple-seam situations. The National Institute for Occupational Safety and Health (NIOSH) is conducting research to develop mine design algorithms that will result in safer multiple seam mines. This paper presents an overview of multiple seam issues in the central Appalachian coalfields. To date, more than 50 case histories have been analyzed from 20 operating mines in Eastern KY, Western VA, and Southern WV. Each case history is classified according to the degree of multiple-seam interaction, ranging from no apparent interaction to severe interaction with direct impacts on mine safety and resource recovery. The case histories are also examined with regard to amount and geologic characteristics of interburden and overburden, and design stability factors. The sequence of mining has also been found to be critical when the lower seam is fully-extracted. This paper compares current case histories to traditional rules of thumb. In addition two situations were modeled using LaModel software. LaModel has been upgraded to import pillar grids and topographic data from AutoCAD files. The cases presented demonstrate vertical stress capabilities of LaModel.

By Joseph Coffman

There are 14 operations that supply 97% of the Market Economy Country (MEC) manganese and contain nearly all of its resources. Six mines account for about 70% of the production and 85% of the resources; there are no known resources that are economically close to those that are currently being mined. Costs (January 1989 dollars) of producing manganese concentrates from the operations evaluated are estimated to range from $ 0.96 to $ 1.86 per long ton unit (ltu or 22.4 lb) of contained manganese. Total MEC demonstrated resources evaluated amount to about 1.2 billion tons of in situ ore containing 474 million tons of manganese. Identified resources amount to about 1.8 billion tons of in situ material. Key results of the study indicate the following: 1. The MEC supply of manganese will be from the currently mined resources well into the next century. 2. Centrally Planned Economy Countries (CPEC's) will be increasingly dependent on MEC manganese ore and concentrate in the future. 3. At the 1976 to 1987 demand increase rate, total MEC resource needed through the year 2000 would be about 282 million tons of in situ material. 4. Transportation and infrastructure support will continue to be major elements of production costs.

Jan 1, 1992

By L. Nahai

THE OUTPUT ff the mineral industry in 1964 in both non-Communist and Communist Europe showed an upward trend for most countries in keeping with the higher index of overall industrial production. Comparable indexes of mineral industry production for non-Communist and Communist Europe (including the U.S.S.R. in Asia) are not available, primarily because the U.S.S.R. does not report details of its industrial production by industrial sectors. However, available data both in the form of index numbers on production published by the United Nations and based on data as reported to the United Nations by the various countries, and actual production data for selected major commodities published by the various European countries reflect generally expanded output by both the extractive sector and the processing sector of the mineral industry in most of the 26 nations of Europe.

Jan 1, 1966

By D. D. Southworth

In 1981, 1982, and 1983, the Bureau of Mines examined the potential for lode deposits of platinum-group metals (PGM) in the Goodnews Bay ultramafic complex, Alaska. The complex consists of the Red Mountain, Suzie Mountain, and Smalls River ultramafic bodies and displays concentric zoning of rock types similar to complexes in southeast Alaska, British Columbia, and the Ural Mountains in the U.S.S.R. Results of the study indicate that platinum is preferentially associated with chromite and magnetite in the dunite core of the complex, and palladium is preferentidlly associated with sulfide minerals in the outer clinopyroxene-rich zones. the most promising targets for PGM lode deposits are the chromite-rich dunite at the heads of Fox Gulch and Squirrel Creek and iron-nickel and iron copper sulfide-bearing magnetite clinopyroxenite and hornblende-rich rocks outward of the dunite core, also in the Fox Gulch-Squirrel Creek area. Significant placer reserves are present in the unmined, deeply buried placer ground in the lower Salmon River Valley, and also in tailings from previous dredging.

Jan 1, 2011

By W. W. Adams

The United States Bureau of Mines, in cooperation with the National Send and Gravel Association conducted a safety contest in 1929 Among producers of sand and gravel. Only 26 plants were enrolled, as the contest was late getting under way. It is hoped that a ranch larger number of plants will be represented in the safety competition of 1930. Two trophies, both of which were provided by Rock Products magazine, were awarded at the end of the contest; one trophy was given for the best safety record among plants working 100,000 or mare man-hours during the year and the other for the beat record among plants working less than 100,000 man-hours. The trophies were presented to representatives of the winning, companies on January 29, 1930, at the annual convention of the National Sand and Gravel Association at Memphis, Tenn.

Jan 1, 1930

By W. W. Weller

Thermodynamic values for scandium and its compounds are very sparse. This is evident upon examination of any of the commonly used compilations of thermodynamic data. For example, National Bureau of Standards Circular 5004 lists only four heat of formation values, two free energy of formation values, and four heat-capacity values for scandium compounds. The entropy of crystalline scandium is one of the most fundamental values that has been lacking. This Bureau of Mines paper reports heat-capacity data for scandium metal in the temperature range from 50° to 298° K., together with the entropy value at 298.15° K. derived from these data through application of the third law of thermodynamics.

Jan 1, 1962