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By Elmer W. Pehrson

The recent establishment of an official price of 64.64 cents per ounce for silver by the President's order of December 21, 1933, has provoked discussion as to the effects of this move on the various metal-mining industries. To assist those of the mineral industry who are interested in this problem, the Bureau of Mines presents the following analysis of basic statistical data concerning; the relation of the silver price to the value of copper ores mined in the United States. The term "copper ore" as used herein includes all ores in which copper is the most abundant base metal paid for. In 1928, this class of ore contributed 98 percent of the total copper output of the United States.

Jan 1, 1934

By John W. Frey

This paper is one of a series of digests of foreign mining legislation and court decisions prepared in advance of a general report relative to the rights of American citizens to explore for minerals and to own and operate mines in various foreign countries. This interpretation of the laws of cw Zealand, as prepared by Dr. Frey the best available information in Washington, has been slightly amplified in accordance with suggestions transmitted through the courtesy of the Department of State by W. L. Lowrie, Consul General at Wellington.

Oct 1, 1929

The Bureau of Mines has long been active in promoting the purchase of coal for Government use under specifications that define the requirements in terms of heating value of the coal, expressed in British thermal units, and the composition as shown by proximate analyses. To these, when required, are added the ash-softening temperature, the free-swelling index, and the Hardgrove grindability index. Under most of these specification contracts, the bidders guarantee the quality of the coal, and that guaranteed by the successful bidder becomes the standard of his contract. The deliveries are sampled in accordance with instructions1 issued by the Bureau of Mines, and the samples are analyzed in the Bureau laboratory to determine whether the coal is of the quality guaranteed by the contractor; if it is not, a price adjustment is made. The Government, with the exception of the Tennessee Valley Authority, purchased approximately 5.5 million tons of coal in fiscal year 1971. In connection with these purchases, the Bureau analyzed 4,366 samples. These are published (table 1) for the use of Government officials and the public. Such analyses of delivered coal and tipple samples (samples collected at mine tipples as coal is being loaded into railroad cars or trucks) provide valuable data for use in evaluating future bids. In addition, the continuous sampling of coal as delivered is a check on the practical results obtained in burning the coal.

Jan 1, 1972

By John E. Miller

A high accuracy Burnett apparatus for use at 12,000 psi and 0° to 65° C has been constructed at the Bureau of Mines Helium Research Center. The apparatus is patterned after Burnett's original apparatus, but the working pressure is much higher and elastic distortion can be essentially eliminated. An operating procedure to permit faster experimental measurements is suggested.

Jan 1, 1967

By Emery Chilton, Charles Taylor, Mark Senk, Linda McWilliams

Three-axis ultrasonic anemometers are used to study airflow in the NIOSH ventilation gallery where ventilation in an underground mine is simulated. In this study, performance characteristics of this anemometer are evaluated and the effects of sensor orientation and sampler location on flow readings are examined. The study results provide guidelines for more effective use of the ultrasonic anemometers in the ventilation gallery.

By K. L. Erickson, Gerald A. Munson

"The need for spodumene as a source of lithia for war purposes led to the exploitation of the Edison pegmatite deposit 1-1/2 miles southeast of Keystone, S. Dak. The operation was conducted during 1943 and 1944 by the Lor Mining Co., Rapid City, S. Dak. Spodumene concentrates in the ratio of 15:1 were recovered by hand picking from a sorting belt. This method was expensive and wasteful of spodumene, owing to the small size of the crystals.Data4/ obtained by the Bureau of Mines indicates that blunging with hydroflouric acid or sodium hydroxide is a prerequisite to selective flotation. Results of tests by Denver Equipment Co., Denver, Colo., indicate that economic recoveries can be obtained in an alkaline circuit after desliming.At the request of the Lor Mining Co., K. L. Erickson, metallurgical engineer, was permitted to work in the pegmatite research laboratory to verify previous investigations and to determine problems that might be involved in commercial milling. The ensuing investigation indicated that electrolytes in the mill water produced a profound inhibiting action on the flotation of Edison spodumone.An investigation of mill water from various sources showed that some waters are suitable for the process and others are not. Subsequent testing showed that all of the available waters are suitable after treatment. The flotation of the Edison spodumene in an alkaline circuit after desliming and using oleic acid as collector is efficient and economical when the water does not contain impurities.In its program of exploration of mineral deposits, the Bureau of Mines has as its primary objective the more effective utilization of our mineral resources to the end that they make the greatest possible contribution to national security and economy. It is the policy of the Bureau to publish the facts developed by each exploratory project as soon as practicable after its conclusion. The Mining Branch, Lowell B.Moon, chief, conducts preliminary examinations, performs the actual exploratory work, and prepares the final report. The Metallurgical Branch, R. G. Knickerbocker, chief, analyzes samples and performs beneficiation tests. Both these branches arc under the supervision of Dr. R. S. Dean, assistant director.As the work was of a practical nature, samples from possible mill-water sources in the southern Black Hills were obtained, and commercial softening and demineralizing methods were investigated. Data on various waters tested are given in table 1."

Jun 1, 1946

By F. C. Gibson

An electrical method for the continuous determination of propagation velocities in opaque, confined explosives, and propellants is described. A resistance element imbedded in the reactive material generates electrical signals that are displayed oscillographically and indicate the position and progress of a reactive zone associated with progress of a reactive zone associated with burning or detonation. The method is applicable to both solids and liquids.

Jan 1, 1963

By M. P. Youker

USE OF LOW-PRESSURE GAS BURNERS IN OIL- FIELD BOILERS

Feb 1, 1922

By D. W. Frommer, M. M. Fine

"INTRODUCTION Laboratory mineral-dressing investigations covered by this report show that ores from Montgomery County, Ark., and Morgan County, Mo., are potential sources of barite and zinc. Fine grinding and froth flotation yielded drilling-grade barite from the former and chemical-grade barite and zinc concentrates from the latter.Samples from these deposits were subjected to a laboratory investigation to develop an economic and feasible treatment. The Arkansas ore, submitted by the Husky Refining Co., consisted of an intimate mixture of the economic mineral and quartz. Fine grinding and fatty acid flotation were utilized to effect a good recovery of a drilling-grade product. The other was a zinc-barite ore submitted by the Rocky Ford Mining Co., Stover, Mo. There was no problem in the recovery of zinc (most of which occurred as sphalerite), but the recovery of barite by flotation was complicated by the presence of gangue carbonates. Ultimately, an excellent recovery of barite was achieved with a relatively new type of flotation promoter, petroleum sulfonate.In recent years, barite has become one of the major industrial minerals as an essential ingredient in heavy drilling fluids, pigments, and chemicals. New sources of this important commodity are always interesting; thus, it is the purpose of this report to present information that may permit commercial exploitation of two deposits not in production."

May 1, 1952

By R. H. Sprute

Extensive Bureau of Mines laboratory testing has shown that electrokinetic densification can be an effective method for dewatering and consolidating unclassified metal mine mill tailings. The report describes results of a limited field test of this technique. Eighteen-cubic-yard concrete model stopes, 18 feet long by 6 feet deep by 56 inches wide, were filled with unclassified tailings slurry from a metal mine in the Coeur d'Alene, Idaho, district. Five different tests were performed. They showed that a strong, dense, dewatered fill can be obtained in a reasonably short time using electrokinetics, with typical power consumption of 25 to 30 kW-hr/yd3 of densified fill. At present power costs in the Coeur d 'Alene district, this would amount to 10 to 12 cents/yd3.

Jan 1, 1975

By Guy A. Johnson

This Bureau of Mines report summarizes the results of efforts to develop reasonably priced, reliable mine shaft fire and smoke protection hardware for metal and nonmetal mines. The hardware was incorporated into a viable prototype system that would minimize fire and smoke hazards. The design of the system had to be sufficiently flexible to be utilized in a wide variety of metal and nonmetal mine shaft and shaft station configurations. As a result of long-term, rugged field tests, an improved (second generation) system was developed. The hardware is now commercially available.

Jan 1, 1978

By C. R. Nisewanger, F. W. Brown

"The velocity of detonation of an explosive is one of its most important properties, because its performance depends markedly on the rate at which it releases its energy. Fortunately, the velocity of detonation is one of the few properties of an explosive that can be measured precisely. However, the velocity of detonation of an explosive may depend on several factors other than its chemical composition, such as density, physical state, degree of confinement, nature of confinement, and magnitude of initiating impulse. Presumably for an explosive of fixed chemical and physical properties there are certain limiting conditions of confinement and initiation under which the explosive will detonate at a maximum constant and uniform velocity. This velocity is its ""ideal"" velocity of detonation. It is obvious, however, that in order to evaluate performance properties of an explosive in all of its applications it may be necessary to measure its velocity of detonation under a number of conditions in which the velocity of detonation is far from the maximum ""ideal"" velocity.. Under certain-conditions the velocity of detonation may even,be,different at different points in the explosive.It is .relatively simple to determine the velocity of detonation of an explosive under a. standard set of conditions if one is free to use large quantities of the explosive and to form it into a convenient shape. Under these circumstances; one can use a thin column of explosive a meter or more in length. The time required for an explosion to travel the length of the column will not be less,of the order a few ten-thousandths of a second and can be readily and accurately measured .by means of the standard spark chronograph or by photographing the explosion with a rotating-drum camera. However in many applications the explosive charge may be of relatively small dimensions arid may not be in a form convenient for making velocity measurements and often may be enclosed in a case or other confining medium. It may be necessary to determine the velocity of detonation over distances of the order of a few centimeters, in which case the time intervals to be measured will be extremely small. For example, the time required for an explosion to traverse 1 centimeter of tetryl is of the order of 1.5 microseconds.Since no satisfactory method of determining time intervals of the order of magnitude of a few microseconds within an explosive charge was available,, at least not for all conditions that might be encountered in practice, it was necessary to develop a special electronic chronoscope which is capable of measuring time intervals as small as a microsecond with a fair degree of accuracy. This report describes the chronoscope and its application to measurements of velocities of detonation in explosives."

Mar 1, 1946

By H. P. Hermance

The Ely mine, which at one time was the largest producer of copper in the United States, has been idle for the past 30 years. A remarkably continuous ore shoot probably averaging 100 feet wide and 19 feet thick was mined on about a 25° slope for 3,400 feet on the incline. The ore was massive sulfides containing chalcopyrite, pyrrhotite, pyrite, and sphalerite. The estimated production of the Ely mine is 400,000 tons of ore averaging 3.3 percent copper. Because of the critical position of copper during the recent war, a search for extensions and recurrences of parallel ore shoots at the Ely deposit seemed warranted. The Bureau of Mines surveyed selected areas by geophysical methods, diamond-drilled nine holes, and sampled mine dumps during its investigations, which began in 1942 and terminated in 1946. The diamond drilling totaled 5,229 feet. The logs of the holes include chemical analyses of mineralized sections.

Jan 1, 1949

By William E. Dennis

"At the request of Philip S. Hoyt, the Eagle Mountain fluorspar deposits in section 35, block 68, Texas & Pacific Railroad Survey No. 9, were examined by an engineer3/ of the Bureau of Mines during March 1943: As a result of this examination; a preliminary program of trenching, sampling and core drilling by the Bureau of Mines was begun in. June 1943.4/ Eight deposits were explored.The Federal Geological Survey mapped the properties and furnished geologic information throughout the program, while the Texas .Bureau of Economic Geology6/ made preliminary maps that facilitated planning the exploratory work on section 35.The eight deposits explored by the Bureau of Mines are in block 68, Texas & Pacific Railroad Survey No. 9, Hudspeth County, Tex., approximately 7-1/2 miles south of. Hot Wells and 12-1/2 miles south of Allamoore, which is 10 miles west of Van Horn and 20 miles east of Gierra Blanco on U. S. Highway 80(fig. 1). A graded gravel road, built by the Public Roads Administration, leads from Hot Wells to the deposits in section 35, and there are unimproved roads, passable,by automobile, to all the other deposits.Carload shipments can be made to and from Hot Wells on the Southern Pacific Railroad, and complete railroad facilities are available at Allamoore on the Texas & Pacific Railroad.Van Horn and Sierra Blanca are the only local source of labor and. supplies. The prevailing wage for common labor is 60 cents an hour. Living accommodations are obtainable in Horn and Sierra Blanca.No electric power lines pass near the deposits. Diesel and gasoline motors are employed to furnish power for mining and milling operations.Two recently 'drilled water wells on section 35 furnish water for the mill. Other wells will be drilled if the present supply is inadequate for prolonged Peak operation.The properties lie in the foothills on the northeast side of the Eagle Mountains at 5,500 feet altitude. The Eagle Mountain Range rises sharply from a broad, flat valley known as Eagle Flat. Eagle Peak, the highest in the range, has an altitude of 7,510 feet. In the vicinity of the fluorspar deposits the topography is moderately reliefs ranging from 50 to 300 feet."

Jun 1, 1946

By W. L. Crentz

San Juan County, which occupies the extreme northwest corner of New Mexico, contains large reserves of coal in the Fruitland formation and in the Menefee formation of the Mesaverde group. The coals have bright luster, are brittle, and break easily in handling. All mines sampled are in the La Plata-Fruitland and Rio Chaco districts of the Durango-Gallup coal field. This large area, all within San Juan County, contains numerous coal beds 5 to 15 feet thick. Ellis2/ mentions the Carbonero (Fruitland in this report) bed in the La Plata-Fruitland district attaining a thickness of 36 feet. This bed has been correlated with the Carbonero bed, formerly mined at Carbon Junction, near Durango, Colo. During the field investigation covered by this report, no operating mine in the Fruitland bed was working a bed thickness of more than 15 feet.

Jan 1, 1957

By Robert T. Langland

The Bureau of Mines, at its Denver, Colo., research center, has developed a computer program to solve nonlinear regression problems. The program is written in a general form so that, regardless of the functional relationship assumed, the unknown parameters may be evaluated by the Newton-Raphson method of iteration. Variances and covariances of the parameters are derived, based on the propagation of errors. A creep function is established from shale test data as an example of program utility. Program accuracy is compared to the accuracies of other programs in present day use.

Jan 1, 1974

A major hazard to workers in underground mines is fire and the resulting contaminated air. Fire reaches miners thousands of yards away with carbon monoxide gas and other toxic fumes. The same ventilation system that furnishes fresh air to miners can also be the vehicle to carry contaminated air to remote locations. To reduce these problems, the U.S. Department of the Interior's Bureau of Mines entered into Contract H0242016, "Mine Shaft Fire and Smoke Protection System," with FMC Corporation, Santa Clara, California, to evaluate mine shaft fire and smoke hazards and to develop and demonstrate a low-cost, reliable mine shaft fire and smoke protection system that would be applicable to a majority of metal and nonmetal mine shafts, including raises and winzes, especially in deep mines.

Jan 1, 2011

By L. C. IlsLey

The service given by a flame safety lame is twofold: It provides a safe light and it gives evidence of the condition of the mine atmosphere relative to the presence of methane and the deficiency of oxygen. Since the development of portable electric mine lamps, flame safety lamps are little used for lighting,but their use as detectors is as extensive and important as ever. A flame safety lamp in the hands of a trained user will definitely how methane concentrations as low as 1 percent, which in well below the lower explosive limit of methane and air. However, this does not always suffice, especially when making studies of mine ventilation, where it may be desireable to detect concentrations below 1/2 of 1 percent.

Jan 1, 1936

By L. C. IlsLey

[The service given by a flame safety lame is twofold: It provides a safe light and it gives evidence of the condition of the mine atmosphere relative to the presence of methane and the deficiency of oxygen. Since the development of portable electric mine lamps, flame safety lamps are little used for lighting but their use as detectors is as extensive and important as ever. A flame safety lamp in the hands of a trained user will definitely show methane concentrations as low as 1 percent, which in well below the lower explosive limit of methane and air. However, this does not always suffice, especially when making studies of mine ventilation, where it may be desireable to detect concentrations below 1/2 of 1 percent.]

Jan 1, 1936

By E. L. Litchfield

Spark ignition of combustible-gas mixtures is a relatively old subject of investigation and has been treated both experimentally and analytically by many people. Elements of static and current electricity are almost always present in mining and industrial operations, and the spark can be an extremely efficient source of ignition. Thus the practical interest of such problems as the "intrinsic safety" of electrical apparatus is obvious. Ignition and quenching phenomena are the primary laboratory representatives of combustion phenomena that are dynamically nonsteady, and such nonsteady phenomena playa considerable part both in industrial processes and in safety matters, although they are of less immediate practical interest. Considerable effort has been expended by the Federal Bureau of Mines in investigations of spark ignition.5 6 7 8/ Primarily, this work has established the significance of several of the parameters involved. Although the

Jan 1, 1959