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By E. D. Gardner

This paper discusses prospecting for lode gold and lists the principal lags and. regulations pertaining to locating; lode claims on public lands. It is a preprint of a part of a bulletin being prepared by the United States Bureau o Mines entitled "Equipping, Developing and Operating Small Gold Mines". The increased interest in gold mining manifested during the past few years (1932-1935) bas stimulated prospecting. Many adventurers have taken to the field to search for now gold deposits. A. large percentage of them have had no previous experience in prospecting for lode gold; this paper has been written with the tope that it might assist these newcomers.

Jan 1, 1935

By Jerry Olson

The Bureau of Mines (Bureau) conducted a mineral resource investigation of the French Creek-Patrick Butte study area, in west central Idaho during 1989. No mineral resources or significant occurrences were identified. Other than small scale placer gold, no mineral production is known or recorded. At least 100 lode and 150 placer claims have been located in the study area. Most of the area was examined by ground or areal surveys, and 110 lode and 60 placer samples were taken. Four lode prospects were examined in detail, and all placer claim locations were sampled.

Jan 1, 1991

In 1962 and 1963, two in situ combustion pilot tests were conducted in the shallow Second Venango sand near Reno, Pa. Because of poor oxygen utilization and lack of production response, both tests were considered failures and were terminated. The area was then relatively inactive until late 1966, when a development well drilled near the 1963 test site had surprisingly good production in what was considered to be a pressure-depleted reservoir. Other wells drilled in and around the old thermal pilot areas also came in as good oil producers. This report presents a study of the increased oil production from the Second Venango sand in the Reno area, and the apparent connection of the present production response and the old thermal pilot tests. Apparently combustion occurred in the Second Venango sand after the 1962 and 1963 experiments were terminated and, supported by large volumes of air left in the reservoir after the 1963 test, generated carbon dioxide which helped repressure the formation. This field evidence of combustion warrants another pilot experiment to further explore the use of properly designed in situ combustion techniques in increasing production from the Second Venango sand.

Jan 1, 1971

By Barry W. Klein

The U.S. economy was considerably stronger in 1976 than in 1974 or 1975. Real gross national product (GNP) rose sharply in the first quarter of 1976 and then increased at a more moderate rate for the remainder of the year. The unemployment rate fell until June and then increased for moat of the remainder of the year, finishing at the same rate as it had started the year. The inflation rate continued to decline in 1976. Reasons for the relatively low rate (compared with those of 1974 and 1975) included small increases in food prices and only moderate increases in energy prices. Total U.S. output measured in terms of GNP increased 11.6% in 1976. Real GNP in 1972 constant dollars rose 6.2%. Inflation as measured by the implicit price deflator increased 5.1%. In real terms, gross private domestic investment for residential structures rose 22.7% in 1976 after declining 14.7%a in 1975; State and local Government expenditures increased 1.4% in 1976; and personal consumption expenditures for services rose 4.5%. The Federal Reserve Board (FRB) index of industrial production increased 10.2%.

Jan 1, 1978

By H. D. Baylor

This is the first of a series of papers describing mining methods and costs at cement plant quarries throughout the United States and deals directly with those methods employed and costs obtained at the quarry of the Louisville Cement Co. located at Speed, Ind. ACKNOWLEDGMENTS The author wishes to acknowledge the assistance of Mr. J. M. Buohheit, superintendent of quarries, and Mr. H. E. Schoonover, quarry engineer, in furnishing data and in compiling this report.

Jan 1, 1930

By Kenneth L. Cashdollar

The Pittsburgh Research Laboratory (PRL) of the National Institute for Occupational Safety and Health (NIOSH) and the Mine Safety and Health Administration (MSHA) conducted joint research on dust explosions by studying post-explosion dust samples. The samples were collected after full-scale explosions at the PRL Lake Lynn Experimental Mine and after laboratory explosions in the PRL 20-L chamber and the Fike 1-m3 chamber. The dusts studied included both high and low volatile bituminous coals. Low temperature ashing for 24 hr at 515°C was used to measure the incombustible content of the dust before and after the explosions. The data showed that the post-explosion incombustible content was always as high as or higher than the initial incombustible content. The MSHA alcohol coking test-was used to determine the amount of coked dust in the post-explosion samples. The results showed that almost all coal dust that was suspended within the explosion flame produced significant amounts of coke. Measurements of floor dust concentrations after LLEM explosions were compared to the initial dust loadings to determine the transport distance of dust during an explosion. All of these data will be useful in future forensic investigations of accidental dust explosions in coal mines or elsewhere. Disclaimer: The findings and conclusions in this report are those of the authors and do not necessarily represent the views of the National Institute for Occupational Safety and Health or the Mine Safety and Health Administration.

Jan 1, 2006

By Ann G. Kim

The Bureau of Mines investigated factors that influence the formation of methane and other hydrocarbon gases in coal, which is an integral part of the coalification process. Coalification begins with a biogenetic stage in which plant debris decomposes and peat is formed; methane and CO2 are the predominant gases produced during this stage. During the diagenetic stage of coalification hydrogen and the hydrocarbon gases methane, ethane, ethylene, propane, propylene, butene, iso- and normal butane, and pentane are formed by dissociation of the organic material. Methane may also be produced by a secondary reaction of hydrogen with unsaturates or by the reduction of CO2. The gas contained in coalbeds is a mixture of methane, C2 through C5 alkanes, CO2, 02, N2, H2, and H2; its heating value is equivalent to that of natural gas. The gas content of coal depends on many variables, but an empirical relationship between adsorptive capacity, rank, and depth has been observed.

Jan 1, 1978

By E. J. Murphy

"INTRODUCTION This investigation is a continuation of previous work 3/4/5/ on the gaseous products of permissible explosives with and without sheaths. The range of oxygen balance of the explosives has been considerably increased. As has been shown previously, certain approximate relations exist between the volumes of gaseous products and the oxygen balance. Further systematization of the data is not feasible, since the method of theoretioal calculatln of the gaseous product is not yet satisfactorily developed. In a previously described method, 6/ it has been assumed that the explosion occurs at constant volume and that thermodynamic equilibrium is established. Apart from the presumably less important uncertainty of some of the thermodynamic data, it is not known how the confinement of the shots in the Bichel gage or the Crawshaw-Jones gage should be treated, or whether thermodynamic equilibrium is fully attained; nor can the extent to which the equilibrium composition changes during the subsequent period of expansion and cooling be judged with any reliability. Therefore, no calculations have been attempted. However, in anticipation of possible future theoretical interest and as an aid in answering practical problems, the new data are presented in the same minute detail as was done previously."

Mar 1, 1948

1. PURPOSE The Temporary Face Support System (TFSS) consisting of beams, posts and carrying-emplacing equipment was developed to provide temporary supports between the working face and the permanent roof supports. 2. GENERAL DESCRIPTION The system consists of: ? A Beam And Post Carrier And Deployer (BAPCAD), a self-propelled machine that carries as well as emplaces the beam-and-post sets. ? Lightweight mechanically self-deploying posts designed to safely support a load of 10,000 pounds each. ? Lightweight constant strength beams (bars) capable of sustaining an approximate equally distributed load of 8500 pounds. Note. All referenced figures and drawings are found at the back of this manual.

Jan 1, 1980

By B. W. Gandrud

In 1927 Coghill5 showed that there is considerable liberation of the iron oxide mineral from gangue when the Alabama red iron ores are ground to a size suitable for classification and tabling, but that there is not sufficient to make possible a high extraction and a high grade of concentrate. Coghill states: High extraction and high grade of concentrate cannot be obtained without grinding to a size comparable with flotation or cyanide practice. If grade of concentrate be sacrificed the grinding need not be so severe.

Jan 1, 1934

By W. E. Cooper

The International Intercalibration and Intercomparison Program (HIP), consisting of several selected laboratories from four countries, held a radon progeny intercomparison measurement at the U.S. Bureau of Mines experimental Twilight Mine on September 12-14, 1988. Grab samples were taken at four different conditions of low and high radon progeny and condensation nuclei concentrations, respectively. The results showed good agreement among all seven participants. The coefficient of variation of all measurements was 4.7%; after minor corrections for flows and some systematic biases, it was reduced to 3.2%.

Jan 1, 1990

By Suresh K. Bhatt

A mathematically simulated modeling technique is used in this U.S. Bureau of Mines report to represent a hypothetical mining operation with existing mining technology and prevalent mining costs. Mining scenarios were prepared and evaluated for potential benefits and costs available through computer-assisted mining. Base criteria, parameters, and methodology are described.

Jan 1, 1993

By M. L. Glenn

The Bureau of Mines is conducting research on Fe-based alloys using Si and Al additions to reduce the Cr required for heat-resisting appli-cations. Part of this research is being done to evaluate alloys containing (8-10)Cr-(10-14)Ni-(0-8.5)Si-(0-4) Al to determine which of these alloys have austenitic structures, as well as fabrication properties and oxidation resistance sufficient to substitute for type 304 stainless steel. Based on initial results, an Fe-lOCr-11Ni-5Si alloy and an Fe-8Cr-13Ni-5Si alloy were selected for evaluation of oxidati.on, stress rupture, and tensile properties. Both alloys have oxidation resistance at 7000 and 8000 C that is better than that of type 304 stainless steel. The stress rupture strengths are less than that of type 304 stainless steel but significantly better than that of commercial heat-resisting steels with similar Cr contents. Yield strengths of the alloys were equivalent to that of type 304. Both alloys had high tensile strengths comparable to those of stainless steels that transform to martensite during straining (e.g., type 301). These alloys have weld-hot-cracking resistance comparable to that of type 304 stainless steel. This initial study shows that Si has potential as a substitute for Cr in stainless steels for heat-resisting applications.

Jan 1, 1984

By E. C. Lane

The motor gasoline that is bring marketed in the United States this stunner is slightly more volatile than that sold a year ago. During the past eight years the Bureau of Mines has made semi-annual surveys of the gaoline marketed in the United States, the survey just completed being the sixteenth in the series. The cities in which samples have been collected have been chosen as representative of the more important marketing territories as it is obviously impracticable to obtain a sample of every gasoline sold in the entire country.

Jan 1, 1927

By D. W. Butner

As a part of the Bureau of Mines program for the discovery and development of critical and essential mineral deposits, the Darwin district, Inyo County, Calif., was chosen for investigation as a possible source of, tungsten ore. Two properties were active in the district at the time. One was producing tungsten concentrate and the other was preparing to produce tungsten concentrate as a byproduct in the milling of lead-zinc ore. The objective of the project set up by the Bureau was to investigate promising areas and to sample, thoroughly those which preliminary inspection indicated contained tungsten ore. Work was begun November 17) 1941, and completed January 19, 1942. In the course of the project, 18 localities were inspected and 9 were sampled. The following pages brief the history, note the location, and outline the physical features and geology of the district. The work performed by the Bureau of Mines is described and supplemented with assay maps.

Jan 1, 1949

By Paul M. Linebarger

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 Mexico has been pro oared from the best information available in Washington but is released subject to correction and amplification, if necessary, by the proper American diplomatic and consular officers, to whom it has been referred through the courtesy of the Department of State. INTRODUCTION Present-day Mexican mining legislation involves, not only the latest minim enactment (August 1, 1026), but many other enactments and regulations, principal among which are the Constitution, the Civil Code, the Code of Commerce, the Foreign Law, the Mining Tax Law, and. the Civil Jurisprudence of Mexico--the last-mentioned being based in Dart on Supreme Court decisions. Ere Mexican Federal Government is supreme in mining legislation because, among other reasons, a large part of the revenue of the Government must come from the fiscal control of the mines. All circulars, decrees, and rulings that affect the mines not only have their origin in the Central Government but are administered thereby. The Department of Industry, Commerce, and Labor is in control of all mines. Attention may here be called, however,

Jan 1, 1929

By G. R. Hopkins, E. M. SEELEY

According to reports received by the Bureau of Mines, Department of Commerce, as of Jamary 1, 1930, there were 1,035 natural-gasoline plants in the United States, with a total daily capacity of 10,516,000 gallons. (These data do not include one small plant in Alaska.) The last similar survey, that of Jamary 1, 1928, showed a total of 1,155 plants of 8,048,000 gallons daily capa- city. This in two years time the number of plants has decreased by 120, but the total capacity has increased 2,468,000 gallons or 31 per cent. This is roughly equivalent to the gain in production over the same periodi Over half of the increase in total capacity was registered in California, where the development of flush oil production having a comparatively high gas-oil ratio in such fields as Santa Fe Springs led to construction of some new plants and material enlargement of others. Of the total plants, 999 were operating on Jamary 1, 1930, and 36 were shut down. This compares with 1,060 operating and 95 shut down two years ago, which indicates a tendency to dismantle plants as soon as they become obsolete or umrofitable. The total daily capacity of the plants operating on Jamiary 1, 1930, amounted to 10,278,000 gallons, or 98 per cent of the total, leaving only 238,000 gallons, or 2 per cent, for the shut-down plants. This contrasts with the refining industry, which usually has 5 per cent of its total capacity idle; the difference is due to the relative ease with which a refiner can secure a crude supply as against the difficulty the natural gasoline manufacturer has in reestablishing his gas connections. During 1929 the average total daily capacity of the operating plants was 9,899,000 gallons, while the average daily production amounted to 6,015,000 gallons. This indicates that the plants operated during 1929 at 61 per cent of their capacity. Although over 60 plants were dismantled in Oklahoma during 1929 the State continued to rank first in total mumber. California was second in mumber of plants with 165, and was one of the few States that showed a gain since the

Jul 1, 1930

By M. M. Tilman

The objectives of this research were to determine the practicability of using cobalt as a means of controlling the amount of ferrite in the micro-structures of semiaustenitic stainless steels, and to determine the effects of reduced ferrite content on mechanical properties of these steels. Cobalt additions of up to 3 weight-percent were made to type 17-7 PH2 (AISI 631) stainless steel. Ferrite contents were determined for alloys in the aged condition, and for alloys quenched from the hot working temperature. Ferrite can be completely eliminated from the microstructure of 17-7 PH stainless steel by additions of cobalt, but complete elimination of the ferrite phase results in lower tensile strength, yield strength, and hardness. Tensile properties, hardness, and impact strength were determined for aged material. A subzero temperature treatment before heattreating was necessary to obtain maximum strength in the alloys containing cobalt. Addition of 2 weight-percent cobalt enhances mechanical properties of 17-7 PH stainless steel.

Jan 1, 1968

By Eric R. Bauer

This Bureau of Mines publication describes and illustrates the physical signs of excessive loading on mine roof supports, installations, and openings. It is designed to assist mine personnel in recognizing potentially hazardous ground conditions, by emphasizing the preliminary effects of developing unstable ground. Increased worker awareness can be expected to reduce the injuries and fatalities resulting from falls of roof, rib, and face.

Jan 1, 1985

By Dennis A. Long

Slip and fall accidents are a major cause of lost-time injuries associated with large mobile equipment in surface mines. An evaluation of the safety hazards associated with getting on and off large surface mining vehicles showed that most of the accidents occur at the point where personnel attempt to mount or dismount the machine at ground level. The major hazardous design conditions were identified as excessively flexible supports for lower steps or rungs, inappropriate ground-level-to-first-step distances, poor step designs, access designs that use vehicle components as steps or walkways, and inadequate hand- rail and guardrail designs, Additional hazards are introduced by the lack of proper maintenance of ladder hardware and the work practices of operators in carrying articles while mounting and dismounting the vehicle. This Bureau of Mines report describes the design and in-mine testing of improved access system for large mobile mining equipment.

Jan 1, 1984