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By D. E. Sullivan

The Bureau of Mines investigated the availability of potash from 68 mines and deposits in 12 market economy countries (MEC's) containing, at the demonstrated resource level, approximately 11.7 billion metric tons (mt) of potash in assay terms of contained K2O; K2O as used by industry as a standard of comparison for the different forms of potash. These resources include almost 190 million mt in the United States, 9.63 billion mt in Canada, approximately 430 million mt in Western Europe (France, Federal Republic of Germany, Italy, Spain, and the United Kingdom), 1.24 billion mt in the Middle East (Israel and Jordan) and over 220 million mt in other countries (Brazil, Chile, and the Congo). This analysis his determined that future production of potash in MEC?s will most likely continue to be from the large resources associated with producing operations in Canada. Based solely on the demonstrated resources included in this study, potash mining in the United States would decline while overseas production from MEC's can continue into the next century at near current production levels. However, timely development of new or inferred resources would offset any such decline. Producing mines in Canada have the resources to increase and maintain increased production well into the next century. For U.S. potash users, Canada is a long-term stable and secure source.

Jan 1, 1986

By H. R. Shell

To obtain a better understanding of the crystallization of fluoride containing amphiboles from melts, an investigation of the range of stability between fluoramphi-boles and other minerals was conducted by the Bureau of Mines. This study has shown that the stability of fluoramphiboles is strongly influenced by both fluoride concentration and isomorphic replacement. Over 150 reactions were made with different compositions and reaction conditions. substitutions attempted and the phases that formed when the composition was crystallized by cooling from the melt are discussed. The attainment of equilibrium in these multicomponent systems is not claimed. Many ions that would be expected to enter the amphibole structure instead resulted in crystallization of phases other than amphibole. Those compositions that resulted in a high yield of acicular fluoramphibole by crystallization from the melts are shown in table 2. The fluoramphiboles obtained from melts typically had an acicular crystal habit and a hardness of 6 to 7 on the Mohs' scale. Although many had relatively high length to cross section ratios, none were fibrous; it was concluded that the possibility of synthesizing a fibrous fluoramphibole from a melt was low. However, many compositions can be crystallized into a tough, hard, impact-resistant mass of interlocking acicular crystals.

Jan 1, 1958

By W. F. Marshall

This report describes exhaust-emission data from 10 diesel engines: six 4-cycle, direct-injection, naturally aspirated engines; two 4-cycle, direct-injection, turbocharged engines; one 4-cycle, precombustion-chamber, turbo-charged engine; and one 2-cycle, direct-injection engine. These engines were tested over a 3-year period (1968-70). Lowest emissions were obtained with a precombustion-chamber engine. Emissions from the 2-cycle, direct-injection engine fell within the range of emission rates for the 4-cycle, naturally aspirated, direct-injection engines. Excluding the precombustion-chamber engine and excepting one of the 4-cycle, naturally aspirated engines, carbon monoxide emission rates were about the same for all engines tested. Test data on smoke, odor, and emissions of hydrocarbons, oxides of nitro-gen, carbon monoxide, and aldehydes are given.

Jan 1, 1971

By A. W. Decora

Gas-liquid chromatography has been applied to separating basic nitrogen compounds, such as pyridines and amines. Close-boiling compounds have been separated by exploiting structural and polarity differences, using selective liquid substrates dispersed on specially prepared solid supports. Development of these special supports was necessary in order to obtain symmetric peaks for basic nitrogen compounds; solution of this problem was important in applying gas-liquid chromatography to the analysis of basic nitrogen compounds found in shale oil. Attempts to analyze shale-oil tar bases by conventional gas-liquid chromatographic techniques, using Chromosorb4/ or Celite 545 as the support for a nonpolar liquid substrate, resulted in asymmetric peaks. These asymmetries were caused by adsorption of sample vapors on the solid support. Symmetric peaks were obtained when strongly polar liquid substrates were used on either Chromosorb or Celite. However, a solid support giving symmetric peaks only with strong polar substrates restricts the choice of substrate, and frequently, desired separations cannot be achieved.

Jan 1, 1961

By C. Melvin Lepper

Microseismic energy is generated when stresses accumulated in rock formations are released in the form of fracturing. The acoustic emissions resulting from these rock fractures and movements are detectable as velocity signals in the earth near the energy source. A Bureau of Mines microseismic system that is capable of detecting the acoustic emissions from pit slope movements is described. The digital circuitry incorporated in the system allows a microprocessor program to immediately calculate and present the location coordinates for the seismic energy source in the mine pit wall. This monitoring system is compact, portable, reliable, and relatively inexpensive and rapidly provides accurate information to the mine operators about the stability of a pit slope.

Jan 1, 1982

By Iain Finnie

This report is in three parts. The first part presents a review of theoretical models which have been developed to study removal operations for various types of materials. In the second part, a brief summary is given of coal cutting research. The majority of this work has been carried out in Britain using chisel type bits rather than the conical picks which are in general use in this country. However, a comparison of specific energies measured for conical picks in the laboratory and in the mine shows very encouraging correspondence. In the third part of the report, analytical models for coal cutting by picks are suggested. An extension of the British "tensile breakage" theory, developed for chisels, is given for picks. The role of crushing and cutting in coal removal is discussed as a theory which combines the two processes is shown to give reasonable predictions for specific energy requirements. Finally, directions in which the existing theory could be improved are presented and the need for further research is emphasized.

Jan 1, 1977

By J. L. Buckley

A survey of previous underground mine fires revealed a number of reported fires may have been caused by malfunctioning stationary electrical equipment. Therefore, an evaluation of conventional fire protection systems was conducted to determine their usefulness in the protection of this equipment. To simplify the problem and facilitate the handling of data, the under-ground mine was divided into nine work areas. Representative combustibles and associated hazards characteristic of each area were identified. Conventionally available fire protection systems were then examined and evaluated to determine engineering and cost feasibility, effectiveness and reliability for the development of fire protection guidelines which could be used within the nine areas of interest.

Jan 1, 1976

The first metal-mine accident-prevention course was prepared and published in 1942-45 as a series of seven miners' circulars (Nos. 51-57). The scope of the course has been broadened, revised, and brought up to date, and it is being published as a similar series of seven miners' circulars on accident prevention in metal and nonmetallic mines. These circulars are: 1. Accident Statistics (Miners' Circular 51), dealing with general statistics on accidents and injuries at metal and nonmetallic mines, including causes, costs, and the uses of investigations and reports of all accidents.

Jan 1, 1957

By R. W. Michelson

The Bureau of Mines developed computerized mathematical models to estimate the economic availability of Mesabi Range taconite concentrates; these are a quality model, a cost model, and an economic availability model. The quality model evaluates metallurgical test data; the cost model determines iron unit cost from mining and processing cost data; and the economic availability model determines quantity from geologic and ore quality data. By correlating all of the physical resource quality factors and dimensional characteristics with the economic cost factors associated with producing iron ore pellets, these three models combine to establish a final relation between iron ore reserve quantities and iron unit cost.

Jan 1, 1970

By S. J. Aresco

The Bureau of Mines has 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 instructions4/ issued by the Bureau of Mines, the samples are analyzed in the Bureau laboratory to determine whether the coal is of the quality guaranteed by the contractor and, if it is not, a price adjustment is made. Analyses of the 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, 1957

By David R. Peterson

This report presents a deep ocean mining operational simulation which is capable of describing the response of the bottom collection unit to specified mining ship maneuvers and the corresponding operation of the mining ship maneuvering system. Bathymetry, obstacles, collector and pipe dynamics and ship maneuvering capabilities are included in the simulation. The simulation is capable of evaluating the technical requirements and operating costs for specified mine plans, Results are useful in assessing mine size requirements and provide operating 'cost 'estimates useful as inputs to deep ocean mining economic feasibility assessments, The simulation is used to determine the consequences of obstacles to mining system operations in terms of impact on mine size requirements and reduced production arising from obstacle avoidance maneuvers of a towed (unsteered) collector.

Jan 1, 1979

By A. Tewarson

Combustibility data are presented for 14 samples representing commonly used mine materials (treated and untreated wood, conveyor belt and brattice cloth). The combustibility data were obtained in the Factory Mutual Small-Scale Combustibility Apparatus (sample area -0.008 m ). The hazards associated with the mine materials were evaluated in terms of: 1) ignition/ surface flame spread using an ignition parameter (IP). A reasonable correlation was found between IP values and U.S. Bureau of Mines ratings for conveyor belts and brattice cloth and large-scale fire test data for treated and untreated timber sets; 2) generation of combustible vapors, using a vapor generation parameter (VP); 3) heat release using a heat generation parameter (HP). A reasonable correlation was found between HP values and the large-scale fire test data for treated and untreated timber sets; 4) generation of "smoke," toxic and corrosive products using a chemical compound generation parameter (CP); and 5) light obscuration by "smoke" using the light obscuration parameter (LP). All the wood treatments, except Fireguard, were found to be effective in reducing the fire hazard. The effectiveness of the treatment appears to be due to enhancement of carbon formation in the solid phase and enhancement of water formation in the vapor phase. Concepts are presented for establishing 1) the relationship between various parameters (IP, VP, HP, CP, and LP) and basic properties of materials, and 2) the usefulness of the parameters as criteria for the combustibility and fire hazard evaluations of the mine materials.

Jan 1, 1982

By R. J. Leary

A small electronic digital computer employing punched cards has been used to facilitate the solution of a variety of problems in Bureau of Mines pyrometallurgical research. In this work the computer has been found to be economical for solving both simple problems that occur repeatedly and those involving complex or iterative calculations. Each of these classes of problems and their respective solutions are described. These small computers can be used effectively by researchers when they work in consultation with a computer specialist. Close team work produces the required solutions in less time, and, oftentimes, in a more useful form. Participation in programming by researchers develops in them a skill for evaluating the suitability of problems for electronic computing.

Jan 1, 1960

By W. J. Kroll

This report is concerned with the many sidelines that were investigated incidental to developing a process to produce ductile Zirconium by members of the staff of the Bureau of Mines laboratory, Albany, Oreg. The results of the main investigation, concerning the production of malleable zirconium by reduction of chloride with fused magnesium under helium, have been described in previous publications. These should be taken as a background to facilitate understanding of this work. Literature on the metallurgy of zirconium has been summarized in a separate publication (2), and references are given in this report only when new publications have to be considered or old ones stressed. Most of the observations described in this report can be applied to the problems involved in making titanium with virtually no change. In general, titanium is easier to reduce than zirconium, since its affinities are lower. Also, its chloride is easier to handle and keep clean because it is a liquid at room temperature.

Jan 1, 1952

By Warren E. Morrison

A simplified energy model for the United States is quantified for a recent historical period. The basic model and calculated quantified structures are used for a number of analytical case studies that estimate midterm and long-range shifts in patterns of energy resources demand and required supply. Historical data series are presented for the years 1947 to 1965 in the form of integrated energy balances by source, form, and consuming sector. In case studies I to XII, conditional projections of historical trends of energy demand and required supply are made for the midterm period 1966 to 1980. The projections are carried out by correlation of major energy components with relevant independent variables such as major economic indicators. Simulations of the medium-range projections to 1980 are carried out by varying the assumptions for the determining variables to produce high-and low-range projections for the midterm period. Case studies XIII to XXII are long term contingency or technological forecasts to the year 2000. These cases assume technological changes or innovations that produce major shifts in the long term pattern of energy consumption and the mix of required resources. The domestic resource base is assessed in its ability to meet projected or forecast demand for energy resources under the midterm and longrun assumptions made in the various case studies. Various energy issues or problems identified from the analyses of the case studies are discussed, and possible alternative approaches to solutions to these issues or problems are suggested.

Jan 1, 1968

By J. J. deBarbadillo

This Bureau of Mines report describes a process for recovering chromium and other metals from superalloy scrap. Laboratory-scale experiments were conducted to test a complex flowsheet utilizing a wide range of extractive metallurgical operations. The novel basis for the process is the fonnation of a sulfide matte in which chromium is concentrated in a discrete chromium sulfide phase. Mineral processing and hydrometallurgical procedures are used to separate chromium sulfide from the other matte constituents. The products of the process are a chromium-nickel alloy suitable for reuse in the superalloy industry, electrolytic nickel, electrolytic cobalt, and iron-molybdenum residue. Recovery of the principal elements contained in the scrap is chromium--93 percent, nickel--99 percent, cobalt--96 percent, and molybdenum--92 percent.

Jan 1, 1981

By John R. McDonnell

The Valle Vidal Unit comprises 100,000 acres In Taos and Colfax: Counties, New Mexico. The unit was donated to the American public In 1982 by the Pennzoll Co. and is administered by the U.S. Department of Agriculture Forest Service as an addition to the Carson National Forest. During 1990-1991, the Bureau of Mines conducted a mineral Investigation of the unit as authorized by an Interagency Agreement (1987) Intended to assist the Forest Service to incorporate mineral resource data In forest plans. The Bureau reviewed literature and records concerning mineral resources and mining activity, and performed a field examination of mines, prospects, and mineral occurrences in and near the Valle Vidal Unit. The La Belle mining district encompasses most of the western part of the Valle Vidal Unit. The district was most active between 1893 and 1902, after the land grant was opened to prospecting and gold discoveries were reported. The discoveries were low grade, and eventually were abandoned. The Bureau's appraisal of the district determined that lode gold occurs primarily in fissure veins in volcanic rocks, and placer gold occurs In weakly cemented sedimentary rocks and alluvial sediments; but at a grade that is currently considered subeconomic. If the price of gold increases in the future, prospecting and exploration in the area may be renewed, but the activity would likely be limited due to "acquired land status" restrictions, which require mineral leasing and prohibit claim location in the Valle Vidal Unit.

Jan 1, 1992

By R. M. Santmyers

Thorium and cerium are two of the group of elements known as "rare earth metals," and are obtained from the mineral monazite. Previous to the employment of thorium and cerium in incandescent gas mantles these elements were nothing more than laboratory curiosities, as the rest of the rare-earth metals are to-day. The most important salts of these rare earths are the nitrates. In the manufacture of gas mantles, thorium nitrate is the principal ingredient and forms prom 92 to 99 per cent of the impregnating material; the other 1 or 2 per cent is largely cerium nitrate and is quite as necessary, for without it there would be little luminosity to the mantle when in use. When the mantle is "burned off," the nitrates are changed to oxides. The monazite used as a source of thoria contains from 6 to 9 per cent of thorium oxide (Th02) and 24 to 32 per cent of cerium oxide (Ce203). As only the thoria and a very small hart of the ceria from the monazite could be used in gas-mantle manufacture, for a time the residues consisting mostly of ceria with somewhat smaller quantities of other rare earths found no commercial application. Later, however, they came to be utilized in several ways, the most important being: (1) the manufacture of cored flaming arc carbons, a great, irmprovement over the plain arc carbons used in electric lighting; (2) cerium metal used in the manufacture of pyrophoric or sparking alloys or "flints" for automatic pocket lighters and miners' lamps; and (3) the production of special kinds of optical and art glass.

Jan 1, 1930

By L. M. Burman

The phase-boundary pressure required to maintain a natural hydrocarbon fluid in a single phase must be considered in planning the recovery of reservoir liquids by miscible-phase processes. The change in the phase-boundary pressure at reservoir temperature that results when a light component or a mixture of light components is added to a reservoir fluid is an especially important consideration. The cricondenbar pressure (maximum phase-boundary pressure) and the critical pressure are unique correlated pressures that have been utilized to calculate the change in phase-boundary pressure that may result when the composition of a reservoir liquid is altered by an additive. In this study one reservoir oil and three gas-condensate fluids are used as examples. Correlations pertaining to the critical and cricondenbar states in chapters 4 and 5 of Bureau of Mines Monograph 10 (3)5 were used to demonstrate how butane and lighter components added to these reservoir fluids affect their phase-boundary pressures.

Jan 1, 1962

By W. L. Cooley

The report provides a detailed analysis of 23 electrical accident countermeasures contemplated for use in the metal/non-metal mining industry. The costs and potential benefits of implementing groups of these countermeasures are estimated, and methods arc outlined by which the operator ran choose countermeasures in an effective manner. The analysis is based largely on an extensive electrical accident event tree which is developed in detail. For those countermeasures which are not currently technically feasible, several prototype devices were developed to help speed development. These included a trolley arc eliminator and a safer mine electricians multimeter.

Jan 1, 1982