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By J. R. Thoenen

This circular is the third of a series summarizing the technical problems involved in the production and preparation of sand and gravel. The first, Information Circular 6668, published in December 1932, discussed the problems involved in prospecting and exploration. The second, Information Circular 6689 (March 1933), dealt with the development of gravel deposits. This is part I of a paper designed to present a study of problems arising in the excavation of sand and revel and their delivery to the treatment plant. Other circulars are planned which will discuss preparation of the material for market, plant storage, and miscellaneous subject. Definitions For the purpose of this circular, excavation is defined as the recovery of sand and gravel from developed natural deposits and their delivery to a plant for market preparation.

Jan 1, 1934

1. Domestic Production and Use: In 1975.12 companies operated 31 primary aluminum reduction plants, with 3 firms accounting for 67% of production capacity. Washington, Oregon, and Montana accounted for 37% of the total production; Gulf Coast States 21%, Northern States 29%, and other Southern States 13%. Output of primary metal in 1975 was valued at $3.0 billion. Aluminum consumption by 25,000 firms was centered in the East Central United States. Of aluminum consuming industries in 1975, building accounted for about 21%; transportation 19%; electrical 14%; packaging 18%; and consumer durables, 9%.

Jan 1, 1976

By Alastair M. Lumsden

A study was initiated to examine the ways in which a number of foreign countries classify and regulate metal/non-metal mines which experience problems due to naturally-occurring flammable gases. Twenty countries were selected for study, and useful information was obtained from sixteen of these. Nine countries were visited (five of them twice) to hold meetings with representatives of government mine regulatory agencies and mine operators, and to visit mines encountering methane and other gases (carbon dioxide, nitrogen). In the later stages of the study seven gassy metal/non-metal mines in the United States were visited so as to provide a basis for comparison, and hence the evaluation of both the U.S. and foreign gassy mine regulations. In addition to obtaining copies of the mining laws and regulations of a number of foreign countries, nine foreign gassy mines, and the seven in the United States were documented in as much detail as possible. All this information is presented, along with appropriate conclusions and appendices. The study took two years and three months to complete.

Jan 1, 1983

By John D. Rockaway

Failure of the mine floor supporting coal pillars frequently occurs when the subcoal strata include "underclays" or other low strength strata. The failure process has been studied to define the response of these materials to applied coal pillar loads and to determine the applicability of bearing capacity analysis to evaluate unsafe conditions. The study has been accomplished through an investigation of both the intact and insitu geotechnical properties of the subcoal strata and through the installation of floor movement monitoring instrumentation. The results of these studies have indicated that both the shear strength of the underclay and the stratigraphy of the subcoal strata must be considered in the analysis. The shear strength was the major controlling factor determining the ultimate load carrying ability of the materials, but the thickness and stratigraphic position of the weak layers influenced the mechanism of the failure process. The methods of bearing capacity analysis were used to define pillar stability that included provisions for taking into consideration a two-layer system. Conditions assumed for a coal mine where a weak underclay overlies firmer strata. The results of the analysis compared very well with observed mine conditions, indicating marginal conditions in areas of the mine which later experienced pillar support failure. In addition, a "heave factor" was derived to predict potentially unstable floor conditions in the mines studied in detail.

Jan 1, 1979

By E. H. Boyle

The Bureau of Mines has evaluated the potential availability of silver from 436 mines and deposits in 41 market economy countries (MEC?s) comprising five major economic categories of deposits: predominantly silver deposits and predominantly zinc, lead, copper, and gold deposits. This study evaluated the long-term cost and availability of primary silver production from 53 producing and 13 nonproducing predominantly silver properties in 11 MEC's and estimated the total recoverable silver from 370 properties as a coproduct or byproduct of zinc, lead, copper, or gold production. This study resulted in estimates of a demonstrated resource of 5.99 billion tr oz of recoverable silver as of January 1984. Of this total, 23.5 pet is in the 66 mines and deposits classified as predominantly silver properties. The largest quantity of recoverable silver, 43.9 pct, lies in the 121 properties classified as predominantly zinc, with 26.5 pct in 120 properties classified as predominantly copper, 4.1 pet in 21 predominantly lead properties, and 2.0 pct in 108 predominantly gold properties. At current silver prices, the economics of silver production favor silver that is a byproduct or coproduct of zinc, lead, copper, or gold, and much of the silver production in the United States from the predominantly silver mines is at an economic disadvantage in comparison with silver production in other countries.

Jan 1, 1986

By D. Randolph Berry

This report describes a study to develop a detailed set of guidelines and equipment recommendations to be used as a guide for mine operators, mine inspectors, and equipment manufacturers in implementing the emergency escapeway standards for metal and nonmetal underground mines. It was sponsored by the United States Bureau of Mines. The first part of this report reviews the historical background of metal and nonmetal mine fires and the development of present and proposed mandatory standards. This is followed by a discussion of the survey of representative mines and how the proposed standard effects these mines. The remainder of the report covers technical discussions of each escapeway component including a comprehensive computer simulation of mine evacuation. Following the technical discussion of each group of escapeway components is a list of the pertinent guidelines. The major escapeway components discussed are the following: Escaperoutes Refuge Chambers Hoisting System. Escapeway Signs Ventilation Fuel Storage Fire Retardants Warning Systems Auxiliary Transportation

Jan 1, 1976

By J. Patrick Ryan, Thor H. Kiilsgaard, Charles W. Merrill, E. T. McKnight

The U.S. Treasury stocks of silver have been reduced at such a rapid rate to meet industrial and coinage requirements that they face exhaustion in 3 or 4 years. Alleviation of the silver problem will require increasing supply or reduc ing demand. This paper examines poss ible long-range resource development and research programs and improved secondary recovery. The possible reduction or elimination of silver in coinage and development and introduction of substitutes in the arts and industry are also discussed.

Feb 1, 1965

By Robert B. Hoekzema

This Bureau of Mines report describes the history, characteristics, distribution, and mineral development potential of 21 lode gold deposits in or near the Chugach National Forest (CNF), AK. It includes findings from a 4-yr (1979 to 1982) mineral evaluation of the CNF conducted by the Bureau and the U.S. Geological Survey (USGS). This evaluation, undertaken to provide the U.S. Forest Service with mineral resource data for use in making decisions on land use, included site-specific mapping and sampling of more than 200-lode gold deposits. The data presented here were compiled from the findings of this 4-yr evaluation and from existing literature. Fourteen of the 21 lode gold deposits described in this report contain a combined identified resource of 117,750 short tons (st) averaging 0.55 oz/st Au and 0.2 oz/st Ag. Two mineralized felsic dikes in the Summit Lake-Palmer Creek area contain a combined identified resource of 18 million st grading 0.02 oz/st Au and 0.16 oz/st Ag. Identified resources were not determined for the remaining five deposits because of a lack of information.

Jan 1, 1987

By Edward P. Barrett

SPONGE IRON has been defined as the metallic product formed by the reduction (removal of combined oxygen) of iron ore or other iron oxides at temperatures below the fusion point of iron. This product probably derived the name "sponge iron" from its porous nature. When the reduction proceeds at slightly higher temperatures and the particles of metal weld together or finally even melt to yield pellets or balls that lack the porosity and low-density characteristic of sponge iron, the product might more correctly be called "direct iron."

Jan 1, 1954

By Haskiel R. Shell

While the original purpose of the Bureau of Mines work on fluorine micas was to synthesize large single crystals or film suitable to replace natural muscovite or phlogopite, the objective was broadened to include development of the many possible fluorine micas as a class of new, unique materials. Several methods were developed for the synthesis of the fluorine micas at atmospheric pressure: Solid state reaction, melting in crucibles, internal resistance electric melting, and arc resistance electric melting. The latter two methods are now med commercially. A variety of fluoromicas were synthesized by isomorphic substitution including disilicic, trisilicic, and tetrasilicic. Fluorophlogopite, KMg3AlSi3O10F2, is the fluoromica most widely used. While most of the fluoromicas are completely stable to water, many water-swelling fluoromicas and fluoromontmorrilonoids were synthesized. Single crystals or film of the fluorine micas were grown to 2 inches or more by a number of methods, but none has as yet proved economical. In the report, detailed data and descriptions are given on compositions, syntheses, products, and uses, and on the properties including physical, dielectric, chemical, X-ray, optical, and structural.

Jan 1, 1969

By R. K. Guthrie, H. B. Hill

"INTRODUCTION The Rodessa oil field in Marion and Cass Counties, Tex., Miller County, Ark., and Caddo Parish, La., was discovered in August 1930, when a well drilled to a depth of 5,506 feet in Caddo Parish, close to the surface trace of the Rodessa fault, produced gas in commercial quantities. During the next 5 years 21 gas wells were drilled, and a large reserve of natural gas was developed in the high part of the Rodessa structure underlying the Massive Anhydrite member of the Glen Rose formation.In July 1935 oil was discovered on the flank of the structure when a well drilled to 6,048 feet also in Caddo Parish, was completed as an oil well. The discovery of oil in the Rodessa structure initiated art intensive development program of more than usual interest to geologists, engineers, and operators in the petroleum and natural-gas industry. The complex nature of the different reservoirs, the large volume of ""free"" gas under high pressures and temperatures in the upper part of the reservoirs, and the high gas:oil ratios of some of the wells during the early production of oil presented many problems the solution of which taxed the ingenuity of those responsible for the development and exploitation of the Rodessa field.Early waste of gas and resultant dissipation of reservoir energy led to State intervention, which brought about effective regulation of the quantity of gas blown to the air. Oil production from wells producing more than 2.000 cubic feet of gas per barrel of oil was restricted, and oil allowables generally were based equally upon acreage and upon reservoir pressures. Consequently, oil-production statistics of the field are closely associated with gas:oil ratios and reservoir pressures.The primary object of this report is to present factual and statistical data on well performance in the Rodessa field and to show established trends under certain operating methods and practices in high-pressure gaseous reservoirs, which have been carefully developed and outlined by modern technique and exploited under close engineering supervision.The large size of the Rodessa field, it’s fairly well defined gas caps, and a somewhat definite water table in a part- of the oil- and gas-producing region are of special interest and importance in a study of the fluid and energy relationships in reservoirs. Consequently, the results of much of the authors' work in collecting and compiling date are presented in the form of tables, maps and cross sections to show the relative thicknesses of the different oil-and gas-producing members and their permeability and porosity relationships, and, when possible, the variations in stratigraphy are exhibited in cross sections. Results of a detailed analysis of cores from a number of wells also are presented in tabular and graphic form."

Aug 1, 1943

By Milford L. Skow

MICA is a group name for a number of complex hydrous aluminum silicate minerals that have a sheet or platy structure and extremely variable and complex compositions containing various metallic ions, particularly those from the alkali group. Muscovite and phlogopite, the two varieties of significant commercial value, are the principal consideration of this report; muscovite has major importance industrially. The mica crystal, because of its laminated structure, can be split easily and accurately into thin films that are transparent, flexible, elastic, tough, and waterproof and have outstanding dielectric and insulating characteristics. This combination of properties is not duplicated in any other known substance. The world production of mica can be divided into two main classifications: (1) Sheet mica and (2) scrap mica (including flake mica). In general, separate divisions of the industry produce these two classes of mica, which differ widely in their uses and in the forms in which they are marketed. A glossary of mica terminology is given in appendix A.

Jan 1, 1962

By Almon F. Robertson

This report is one of a series based upon investigations made and being made within the Missouri River Basin in Montana by engineers of the Bureau of Mines , Albany Branch , Mining Division . These investigations are being made primarily to provide preliminary information to the Department of Interior agencies and to others concerned with planning the proposed Federal power developments within the Missouri River Basin. This report has been designed to permit public distribution of the factual data obtained . Virtually all known metallic -mineral occurrences and some nonmetallic mineral deposits within Fergus County were investigated in 1948. The investigations cannot be considered complete , however , because some long inactive mines or prospects may have been missed . Most of the old mine and prospect openings now are caved ; many are completely inaccessible . Many of the claims located years ago have been abandoned ; others have been relocated under different names and ownerships . Because of such conditions , much of the information regarding their development and operation necessarily has been obtained from available Federal and State publications , supplemented by information provided by owners and local residents .

Jan 1, 1950

Duty on Lead Reduced. -On December 28, the President signed H.R. 5047 which reduces the duty on unwrought lead from 3.5% ad valorem to 3% ad valorem, with a floor level of 1.0625 cents per pound, effective retroactively from January 1, 1980, through June 30, 1983. Pacific Northwest Power Bill Passed. -On December 5, the President signed S. 885 which will enable the Bonneville Power Administration to guarantee 20-year contracts to its 15 major industrial customers in exchange for higher rates. In effect, the bill will have industrial customers pay some of the costs of building additional generating facilities in the Northwest, of which thermal units are expected to be a major part. BPA supplies power to six primary aluminum producers which operate eleven plants having over 30% of the primary aluminum capacity in the United States.

Jan 1, 1980

The value of domestic raw nonfuel mineral output in 1985 was estimated at $23.7 billion, 2% above the 1984 value of $23.1 billion. This crude mineral output was the basis for approximately $244 billion worth of processed materials of mineral origin. [ ] A U.S. company permanently closed its alumina plant in St. Croix, U.S. Virgin Islands, reducing domestic alumina capacity by 10%. Another U.S. company sold its 26% interest in an alumina plant in Jamaica to its two U.S. partners. On completion of the purchase agreement, the two remaining partners promptly closed the plant for an indefinite period, citing a world oversupply of alumina and unacceptably low prices.

Jan 1, 1986

By O. P. Hood, R. H. Kudlich

When a gasoline locomotive is used in a mine there is danger of the noxious gases of the exhaust vitiating the air, but if enough air is circulating in those parts of the mine in which the locomotive is used, these gases are so diluted that they are rendered harmless, and the health of the workmen is not affected. In some mines the use of gasoline locomotives is impracticable, though in the majority of mines where they have been tried they have proved to be safe and economical. To determine the limitations that should surround the use of these machines in mines so that they shall not be detrimental to health and so that their economic advantage may be retained, it is necessary to ascertain the volume and the character of the exhaust gases and the amount of these gases that may be safely allowed in the mine air, and also to determine safe conditions of operation. The problem is primarily one of ventilation and like all ventilation problems must be intelligently computed to meet the conditions of each mine. The investigation described in this bulletin was undertaken 'by the Bureau of Mines in an endeavor to obtain exact information on some of the basal questions involved in the use of gasoline locomotives in mines, this investigation being one of many that the bureau has been conducting in its efforts to increase safety and efficiency in mining.

Jan 1, 1915

By W. F. RITTMAN, E. W. Dean

This report presents the results of an investigation conducted by the Bureau of Mines for the purpose of assisting in the establishment of a satisfactory standard method for the analytical distillation of petroleum, a problem of great importance to the petroleum industry. Experiments were performed for the purpose of studying the charac- teristics of methods typical of those in use; comparative studies were made of the efficiencies of the principal types of fractionation ap- paratus available to the petroleum chemist; and the characteristics of a type of apparatus that the results of the experiments seemed to indicate was best adapted to the purpose were investigated in detail. Also, some experiments were made to determine the effect of cracking as a factor in the analytical distillation of petroleum in still heads.

Jan 1, 1916

By T. C. Moore

This report describes the feasibility test of an electromagnetic method for locating boreholes, with or without casing, that have been drilled in conjunction with mining operations but whose location with respect to the tunnel is not precisely known. The first tests were conducted with the cooperation of the Kerr-McGee Corporation, Church Rock Mining Operations, New Mexico, in September 1977. These tests demonstrated that accuracies of better than ±5% of range and ±1° of bearing can be achieved with a simple system and setups. Subsequent tests, in January 1978, on a horizontally drilled pipe line river crossing application, by Titan Contractors of Sacramento, California, demonstrated that accuracies of better than one-half percent of range and a few tenths of one degree of bearing can be achieved by using refined techniques. The demonstration tests were done at ranges on the order of 100 to 200 feet but the method is capable of working at much greater distances.

Jan 1, 1978

By WL Wagner

This report presents a quality control approach to the derivation of strategies for monitoring a work environment; specifically, the environment in underground mines where diesel-powered equipment and blasting agents are used. The approach is presented as a series of 22 steps called the Monitoring Strategy Development Scheme. The scheme is an orderly method for selecting from a number of options a strategy or tactics to cost effectively meet the requirements of a chosen objective related to the monitoring of breathing zone air quality. The scheme provides a format to quantify many of the factors that influence the selection of on strategy or tactic over another, and to ensure that important considerations are not neglected. The premise that breathing zone air in work environment can be considered to be manufactured product and that, therefore, conventional quality control approaches are applicable, is introduced. Typical approaches to the quality control of manufactured products and how these approaches can be applied to the selection of monitoring strategies are discussed.

Jan 1, 1983

By W. W. Adams

Coal mining in the United States established a good safety record in 1939. The death and injury rates per man-hour of exposure to risk were favorable compared with most previous years, and the number of persons killed or injured in proportion to the quantity of coal mined was also lower than in any other year for which figures are available. Moreover, productivity per man-hour was higher than ever before. The number of man-hours of work performed increased 9 percent over 1938, but there was a slight decrease in the number of men employed. Reports from operating companies showed 539,375 men employed during the year, and the period of operation averaged 179 workdays per man. Man-hours of work numbered more than 678 million. Accidents to the workers resulted in 1,078 fatalities and 54,015 nonfatal disabling injuries, causing disability of the employee for more than the remainder of the clay on which the accident occurred. For each million man-hours of exposure of the employees to mining hazards the fatality rate was 1.59 compared with 1.78 for 1938, and the injury rate was 79.65 compared with 82.61 for 1938. Production of coal averaged 0.661 ton per man-hour compared with 0.637 ton in 1938. The weighted average length of the workday was 7.03 hours or virtually the same as the previous year's average of 7.04 hours. Measured in man-hours, the average period of employment per man was 1,257 hours in 1939 and 1,147 hours in 1938.

Jan 1, 1942