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By L. C. IlsLey

The United States Bureau of clines has been conducting Investigations of electrical equipment during a period of more than 25 years in an endeavor to encourage the development of safer electrical equipment for coal mines. In order to conduct these investigations in an orderly manner they are carried out under a published schedule of tests known as Schedule 2C, which specifies detailed requirements for motors, controllers, etc., and fees covering the various inspections and tests made as part of a routine investigation.

Jan 1, 1937

By Charles J. Cohen, Donald F. Reed

"INTRODUCTION AND ACKNOWLEDGMENTSThis report supplements a previous report on work done in this same area 4/ but covers only the period from November 1945 to November 1946. The project was established in 1943 to investigate magnetite deposits in the northwestern Adirondacks by geophysical surveying and diamond-drilling for the purpose of increasing iron production in the eastern United States.In its program of investigation of mineral deposits, the primary objective of the Bureau of Mines is the more effective utilization of our mineral resources, that they may make the greatest possible contribution to our national security and economy. The policy of the Bureau is to publish the facts developed by each project as soon as possible after its conclusion. Maps showing the detailed magnetic surveys of the deposits and anomalies discussed in this report are on open file at the offices of the Bureau of Mines, College Park, Md., and at the University of the State of New York in the office of the Director of the State Science Service, Educational Building, Albany, N. Y.The Mining Branch, Lowell B. Moon, chief, conducts preliminary exami¬nations, performs the actual investigations, and prepares the final report. The Metallurgical Branch, Oliver C. Ralston, chief, analyzes samples and performs beneficiation tests.The chemical analyses included in this report were made at the Eastern Experiment Station of the Bureau of Mines at College Park, Md., under, the general supervision of J. B. Zadra, chief, College Park Division, Metallurgical Branch, and the immediate direction of Dr. Alton Gabriel, in charge of the laboratory service unit."

Nov 1, 1947

By R. S. Dean

"INTRODUCTION The metallurgical research program of the Bureau of Mines has been somewhat disorganized, but generally advanced by the increased activities of the war period. The present report is for the purpose of summarizing the work of the Bureau in this field for the past 15 years and indicating its future plan.Fifteen years ago the Bureau turned from its pioneer work on the physical chemistry of steelmaking to an emphasis on raking a pure steel synthetically, rather than by refining, that is, :producing each of the steel 'constituents in the pure state and combining them by simple melting. Such a procedure permits the use of less high-grade ores, not only of iron, but of the ferroalloy metals, such as manganese and chromium,This program has led to extensive work on iron-ore concentration, agglomeration, reducibility of ores and agglomerates, direct reduction of iron ores and concentrates by a wide variety of processes; special refining processes for iron, the production of pure mangenese, chromium, and cobalt from low-grade ores by electrolytic processes, the production of ferrochromium, ferronickel, and ferronickel-cobalt from low-grade domestic ores, and the development of many special alloys to effectively use the new products.The status of the work in each of these fields and the future program of work, together with a bibliography of papers and patents by the Bureau staff on each of these subjects, are given."

Jul 1, 1946

By J. W. Thompson

A contract stipUlating for the delivery of quantities of phosphate rock" f. o. b. mines," and stipUlating that" while this contract is in form an absolute sale for a fixed quantity in each year, it is mutually understood and agreed that the purchase is for the buyer's consumption and not for a sale; the buyer agreeing to give to seller the refusal of any surplus over and above the actual consumption. Buyer is at liberty to increase or diminish the quantity called for in any year, to the extent of not exceeding 10 per cent; provided that the quantity to be taken shall not be less than buyer's consumption; provided further that notice of such increased or diminished demand be given seller 12 months in advance of such change," is to be construed as a contract for the sale of stated quantities of rock, deliverable in approximately equal quantities during each year for the specified series of years, subject only to be increased or diminished after specified notice in any year, where the amount taken would not be les<; than the buyer's consumption, not exceeding 10 per cent, and the contract indicating that the rock was intended by both parties for consumption in the fertilizer plant of the buyer. but the quantity to be taken was not limited by the necessities of' the plant.

Jan 1, 1916

By E. Don Dilling, W. F. Holbrook, Lloyd R. Michels, James W. Pennington, Dwight L. Harris, Wm. F. Hergert, Cyrus L. Blogett, H. A. Doerner, Ernest A. Reige

"IntroductionA process for production of magnesium by carbothermal reduction was developed at Padentheirm, Austria, by the Austro Americanische Magnesit Corporation& an independent investigation of this and other processes was started in 1937 by the Bureau of Mines at Pullman, Wash., with the cooperation of Washington State College. 10/ A preliminary study of the Radentheirm pro¬cess, as revealed by the meager information then available, demonstrated the following two major disadvantages,The use of hydrogen for shock cooling requires an enormous volume of gas - about 1,000 cubic feet for condensing each pound of metal as a pyrophoric dust which must be completely separated from this gas. Then if the gas is to be recycled for repeated use, the CO produced by the reduction reaction must be separated from the hydrogen. These separations are costly from the standpoint of equipment and operation. 11/The condensate is an impure, pyrophoric metal powder that must be purified and converted to coherent form. This is accomplished by distillation or sublimation of the metal. Distillation on a large scale involves difficulties inherent in the high boiling point (1,107° C.) and the chemical activity of the metal. To avoid these difficulties, the metal is sublimed at 600° C. and of very low pressure. This is quite easily carried out as a batch operation but is a costly procedure. A continuous sublimation process has not been accompli shed."

May 1, 1945

By G. G. Huggins

A demonstration project has been completed to reduce the operator sound level of an underground service vehicle, a personnel dispatch wagon, to go dB(A) or less. The program objective was to implement quieting recommendations made on an earlier study for the USBM n diesel-powered mine equipment. The manufacturer and mine to which the vehicle was going actively participated in the program to ensure a product that was not only quiet, but useful. The key element of the quieting package is an engine part a1 enclosure, which, with several complementary noise control components, reduced the operator sound level 14 dB, from 101 dB(A) to 87 dB(A). The vehicle underwent a 4-month trial period, with no degradation in the quieting package. Mine personnel reported no maintenance difficulties, and were enthusiastic about the dispatch.

Jan 1, 1975

By S. H. Lorain

Tin mining on Seward Peninsula, Alaska, has been intermittently active since the early 1900&apos;s. Most of the recorded production (over 2,200 short tons of metallic tin) has been obtained from placer deposits, but recent production also has resulted from development of lode deposits associated with intrusive rocks occurring in the western part of the peninsula. Generally, the lode deposits containing tin minerals (principally cassiterite) are found in dikes, in granite masses, and in silicate zones in limestone overlying the granite. Both the placer and lode deposits have been of considerable strategic interest to the Government because of the almost total absence of a domestic supply of tin. The most important tin-lode deposit discovered to date is in the Cassiterite dike at the Lost River mine, on Cassiterite Creek about 85 miles northwest of Nome. This highly altered, rhyolite porphyry dike averages 12 feet in thickness, strikes N. 75° to 85° E., and dips steeply to the south; it can be traced on the surface for about 8,000 feet. Throughout its explored length of about 2,200 feet the dike everywhere contains some tin and tungsten in veinlets and disseminations; economic concentration of the are minerals, however, is confined to definite shoots. The ore minerals include cassiterite, stannite, hulsite, paigeite, wolframite, scheelite, and base-metal sulfides; gangue minerals include fluorite, boron silicates, and lithium-bearing minerals. Some ore minerals also occur in the numerous other dikes and in the granite and intruded limestone in and adjacent to the mine.

Jan 1, 1958

By M. F. Boos

The Portland beryl-mica district, Middlesex County, Conn., comprises three deposits investigated by the Bureau of Mines in 1943. The Gotta-Walden deposit is in a pegmatite dike 4 to 20 feet thick, which cuts gneiss and schist. In general, the hanging wall is rich in mica and beryl with some feldspar, quartz, and garnet. The central core is usually high in quartz and feldspar, with relatively little mica and beryl. The footwall comprises quartz and feldspar, with varying amounts of mica and some beryl. The beryl crystals range in color from green to almost golden and have a maximum diameter of inches. Results of surface trenches indicate a beryl content of 0.81 percent for the pegmatite. A small production of beryl, feldspar, and scrap mica has been made from the deposit.

Jan 1, 1949

By Jack L. Woodward

The evolution of surface mining equipment has resulted in larger, faster haulage units, loaders, etc., resulting in increased demands on steering technology. Careful analysis of these systems was warranted to determine if steering-related safety problems have been introduced. The objectives of this program were to: 1. Define the generic types of steering systems being used on mobile mining equipment used in surface mining operations. 2. Gather information on steering-related accidents in mining operations. 3. Assess the need for initiating government-sponsored research into steering system technology. A comprehensive literature survey was conducted concurrent with extensive contacts with mining operations, mining equipment manufacturers, steering system component manufacturers, and government agencies. A Technical Evaluation Group composed of representatives from the above organizations was formed to review the data gathered. It was concluded that the steering systems in use on surface mining equipment are reliable and do not present a safety problem. The Society of Automotive Engineers, Inc. is active in pre-paring voluntary consensus standards to assure that the minimum levels of performance are defined for industry.

Jan 1, 1979

By Charles G. Maier

"INTRODUCTION The use of thermodynamic calculations to answer practical problems in metallurgy, especially those that are relatively difficult to test experimentally, is rapidly becoming a conventional method of procedure. Nevertheless, these methods cannot he applied effectively until the fundamental thermodynamic constants used for them have become available either by direct experiment or by recalculation of data already existing in more or less undigested form.In an attempt to collect such data far the compounds of lead and the antimony group the incentive has been to make a preliminary survey that will disclose the gaps or questionable phases of available information and to collect data that may be used to answer certain rather practical problems presented by operating metallurgists.This report comprises three sections; the first gives the basis of selection of the constants which may now be given or estimated, and the later sections discuss the application of the figures obtained to two of the more interesting problems.The reader will discover that many of the quantities involve critical study of a number of more or less discordant observations. Although certain data could be rejected on the basis of thermodynamic comparisons, it must not be overlooked that many of the figures are the results of rational estimates rather than exact experiment. The use of thermodynamic methods to control and partly authenticate such estimates is one of its most valuable characteristics for the practising metallurgist or chemist, who cannot check by direct experiment each property of the materials which he converts to usable form.Nevertheless, while it is definitely possible in certain instances that the final figure selected for the heat or free energy of a process or substance may be in error by as much as a few hundred to a few thousand calories per formula weight, questionable figures are usually revealed by the thermodynamic calculations made. When quantities of such degree of accuracy are, and they often must be, used for estimating an unknown reaction, the result often gives no more than the order of magnitude of the desired quantities. Yet even in these extreme cases the answer is far more reliable and valuable than an unordered guess or a conclusion based on incorrect data."

Dec 1, 1934

By L. C. IlsLey

The United States Bureau of Mines has been conducting investigations of electrical equipment curing a period of more than 25 years in an endeavor to encourage the development of safer electrical equipment for coal mines. In order to conduct these investigations in an orderly manner they are carried out under a published schedule of tests known as Schedule 20, which specifies detailed requirements for motors, controllers, etc., and fees covering the various inspections and tests made as part of a routine investigation.

Jan 1, 1937

By D. Harrington

Although it is impossible to give definite final figures at this time on Nation-wide accident occurrence in 1933 , enough data are at hand to indicate that the progress in safety in the mining industry, which first became apparent in 1930 and was accentuated in 1931 and 1932 , was continued and much improved in 1933. This improvement was of considerable magnitude in mining both bituminous coal and anthracite but was not so great in other branches of the mining industry . While the volume of work done in all phases of mining increased in 1933 over that in 1932 , the exact amount of the increase is not yet known . Usually increased activity in mining is accompanied by even greater increase in the rate of occurrence of accidents to the workers , but happily it appears that this " rule " was not operating in 1933 --at least in the coal -mining industry .

Oct 1, 1934

By Ira L. Wright

This paper describing the milling practice of the Black Hawk Consolidated Mines Co., is one of a series being prepared by the United States Bureau of Mines. ACKNOWLEDGMENTS Part of the information contained in this paper was furnished by I. H. Stanley, mill superintendent, Black Hawk Consolidated Mines Co., Hanover, M. M., and a part by the South-western Engineering Corporation, Los Angeles, Calif. The assistance of T. G. Chapman in arranging the paper for publication is also acknowledged.

Jan 1, 1930

By J. D. Warne

The ferberite district of Boulder County, Colo., has been an important producer of tungsten since 1900. During World War I, high prices for tungston concontrates resulted in a brief period of intense activity, and the production in 1917 was 2,707 tons of 60 percent W03 concentrates. Production declined thereafter, and in 19.2 the tungsten produced in Boulder County represented about 4 percent of the Nation&apos;s output, being exceeded only by the scheelite production in California, Nevada, and Idaho. Boulder County has boon an important source: of tungsten in the Korean emergency; the present report does not describe this recent activity, as it will be covered by a future publication. Tungsten occurs in small ore shoots of narrow and irregular veins. Most of the ore shoots have been found outcropping on the surface. Core drilling; has been used by the larger operators to explore for new veins and to locate extensions of known veins.

Jan 1, 1953

By Neal M. Miur

"INTRODUCTION The Mineral Ridge-Clay Lick fault system in Crittenden and Livingston Counties, Kentucky, is one of the larger and more important fault systems of the Western Kentucky Fluorspar district. Total production from it up to July 1945 (chiefly since 1900) was approximately 80,000 tons of fluorspar ore, 10,000 tons of which came from the Mineral Ridge Fluorspar Co. tract 1, which was being operated by the Mahoning Mining Co. of Rosiclare, Ill. The fluorspar ore carries lead and zinc that can be recovered by milling, and the Mahoning Co. planned to log-wash the ore at the mine and then mill it in its mill at Rosiclare, The Mineral Ridge Fluorspar Co. properties were examined by O. M. Bishop, an engineer of the, Bureau of Mines, in August 1942. During 1943 and 1314, developments on the properties were under observation by X. B. Starnes, of the Bureau, and it was decided to diamond-drill tracts 1 and 2, as indications seemed favorable for opening up additional fluorspar ore bodies. Drilling was begun March 12, 1945, and was completed July 2, 1945, during which time 12 holed were drilled on tract 1 of the Mahoning Co.'s leases for a total of 3,637.1 feet, and one hole 359 feet deep was drilled on tract 2 of the Jennings lease. The Mineral Ridge-Clay Lick fault system, 4 to 47 feet wide, was encountered in all holes at 126 to 265 feet."

Apr 1, 1947

By N. A. C. Smith, E. W. Dean, W. A. Jacobs, H. H. Hill

Fractional distillation is the most important process in the commercial refining of petroleum. The same procedure, conducted on a small scale, is the basis of a number of analytical methods of wide application in the petroleum laboratory. The Bureau of Mines has studied apparatus and procedure for the distillation analysis of petroleum, and this report is presented as a record of developments up to the present time. The work is incomplete, but the extensive information that has been obtained to date is made available as a guide in handling laboratory distillation problems. The analytical distillation of petroleum is commonly made to determine range of boiling points or to separate the oil. into fractions for detailed examination, or both. When only one of these two ends is sought the procedure involved is notably simpler than when, as is more common, information is required regarding both boiling range and properties of fractions. Moreover the degree of minuteness of measurement and the accuracy of the data required from analytical distillations differ considerably. Often the simplest sort of comparative figures are satisfactory; other tests require complicated and highly tedious procedure. No one distillation method is universally applicable, and it is impossible for anyone group of investigators to foresee all the different kinds of requirements that may occur in the industry.

Jan 1, 1922

By Richard A. Watson

A frequency-shift keying (FSK) modulator-demodulator (modem) network has been devised for the Bureau of Mines mine-monitoring systems. This network permits an unlimited number of remote stations to communicate with one central station over the same pair of wires. The network operates at a speed of 4,800 Bd at distances up to 5 miles. This report describes the development and operation of the modems. The theory of operation, schematic diagrams, and printed circuit board layouts are provided. Although the modems were built for a specific application, a more general use is discussed whereby the network would operate with a typical serial channel format.

Jan 1, 1985

By Leonard Obert, Wilbur Duvall

"INTRODUCTION 'The investigation reported herein is part of a comprehensive research program being conducted by the Metal Mining Research Section, Mining Division, Bureau of Mines, on pressure problems in underground mines. This program was initiated in 1937 and for the first 3 years was concerned primarily with measurement of the pressure on mine pillars and supports and their strength. 4/ 5/ During this period, investigations were conducted in both the laboratory and the field in the comparatively shallow load and zinc mines of Missouri and Oklahoma. As a result a seismic method of determining the pressure on mine pillars was developed.Before this research program was initiated, Chas. F. Jackson, chief of the Mining Division, suggested that rock under pressure might give rise to noises inaudible to the unaided ear - that is, subaudible noises. As a result of this suggestion, listening tests were made concurrently with the routine pressure measurements to see if any rock noises were present; with one exception, it was found there were no rock noises in any of these shallow mines. At the same time, pressure measurements disclosed that, with one exception, pillars were not under pressure amounting to more than 10 percent of the crushing strength of the rock. The one exception was a pillar in the Big John mine of the Eagle Picher Mining & Smelting Co. in the Tri-State district, which showed some physical evidence of failure, such as small cracks and spalling; it was reported that the pillar had been heard to crack or snap at intervals. Listening tests in this pillar disclosed that subaudible noises of comparatively small intensity were present and occurred at 1- to 2-minute intervals, on the average. Unfortunately, owing to the shortness of this pillar it was impossible to make any pressure measurements."

Jul 1, 1942

By Serge Rudchenko

A study to determine the potential use of retaining structures in open pit backfilling. Research and review of the open pit mine environment, mine waste disposal, and past and current use of retaining structures. A development of specific structures, the culvert/ tunnel concept, and an anchor block retaining concept. The cost benefit of retaining structures used for in-pit backfilled waste.

Jan 1, 1981

By Curtis A. Jones

Continuing interest has been shown in developing processes for extracting nickel and cobalt from low-grade domestic deposits of these metals and in improving existing methods. Of special concern is the nickel-recovery installation at Nicaro, Oriente Province, Cuba, operated for the General Services Administration. The Bureau? of Mines felt that a bibliography would help familiarize personnel at various Bureau of Mines stations and General Services Administration contractors with extraction methods both in the United States and in foreign countries. When this task was under way it became apparent that to compile a complete bibliography would require considerable time, so it was decided to limit the first part to the later literature and issue it independently, thus making it available sooner. The present work supplements the first part and extends the coverage to the earliest years of nickel and cobalt metallurgy.

Jan 1, 1959