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By Charles L. Kimbell

In 1988, the aggregate value of total world international export trade in mineral commodities was estimated at nearly $542 billion in current (1988) dollars, which was about 8.6% above the 1987 level, but still 23.7% below the record high set in 1980. Comparable comprehensive data for 1989 were not available in time for inclusion in this chapter, but 1989 returns for developed market economy countries only were 1 1.8% above those for 1988. These countries accounted for about 50% of the total mineral commodity export trade in 1988. It would be unsound to utilize the overall 11.8% growth rate for mineral commodity export trade for these countries to extrapolate the growth in total world mineral commodity trade because these developed market economy countries account for substantially different shares of the five major mineral commodity groups listed in table 2. Specifically, developed market economy countries in 1988 accounted for 56% of world export of ore, concentrate, and scrap, 74.7% of world exports of iron and steel, 71.7% of world exports of nonferrous metals, and 57.8% of all exports of crude nonmetals, but only 26.6% of world exports of mineral fuels. Moreover, even within each of these groups, the actual product mix included in developed market economy country aggregates differ from that in developing market economy country aggregates and in centrally planned economy country aggregates. Nonetheless, an increase of 9% to 12% in the value of world mineral commodity export trade seems indicated by available returns.

Jan 1, 1992

By John E. Husted

Quantities of kaolin in Georgia in-contiguous or single bodies had been established by previous work to be sufficient for an alumina industry. The need for characterization of this kaolin to determine its suitability as an ore of aluminum resulted in the studies described herein. It was determined in an area roughly 7 x 27 miles, known as the Wrens district that approximately 5.9 billion short tons of kaolin averaging 35.55 percent A1203 exist in an essentially continuous clay body. The Macon-Sandersville district consists of discontinuous kaolin bodies averaging 35.28 percent A1203 with an average thickness of 28 feet. Tonnages for this district are not available. One hundred and twenty core samples of kaolin were analyzed for K20, CaO, MgO, Al203, T102, Cr203, Fe203, Si02, P205, and F. The P205 and F were analyzed by wet chemistry methods and the others by electron microprobe. Seventy-nine of the samples were from the Wrens district forty from the Sandersville-Macon district and one from the Andersonville district. Emission spectroscopic analyses were also made to qualitatively determine all elements present for each core. X-ray diffraction studies were made of each core to determine mineral species present. Scanning and transmission electron microscope pictures also are given for each I' core sample. Elevations, overburden thickness, and kaolin thickness are given for each core site as well as map locations. Isopachs for over-burden and kaolin thickness are given for the Wrens district.

Jan 1, 1983

By Robert C. Bates

Variations in water percolation rates through saturated cohesionless hydraulic backfill (mill tailings) have been studied in relation to the many physical aspects of the system to determine the most important factors in causing these variations. A multivariable least-squares regression analysis of 135 separate tests shows that a reliable estimate of the water percolation rate through typical hydraulic backfill can be made if the bulk density (unit weight), specific gravity, and grain-size distribution are known or can be estimated. Equations for predicting percolation rate, coefficient of permeability, and seepage velocity are developed both for the range of data analyzed and for extrapolation. The prediction equations for use within the range of data studied are quite accurate, while the ones developed for extrapolation are less accurate but still give reasonable approximations of flow rates. The equations given are valid for cohesionless materials that are free of clays and micas, exemplified by classified mill tailings. The equation developed for predicting percolation rates is as follows: 1nP20 = 11.39147 + 2.853422 1n(VR X D10) + 0.1747436 VR X Cu -178.8039 D10 X D50 + 311.7034 (DSO )3, (1) where P20 = percolation rate, inches per hour at 20° C; correction factors for other temperatures are given in the text, VR = void ratio, dimensionless, D10 = effective size (diameter in millimeters of the 10-percent-finer grain size), Cu = coefficient of uniformity (ratio of the diameter of the 60-percent-finer grain size over D10), D50 = average size (diameter in millimeters of the 50-percent-finer grain size), and In = natural logarithm (log to the base e). The prediction equation for percolation rate is rather complicated, so for practical use a nomograph that simplifies the solution of the prediction equation was developed.

Jan 1, 1967

By F. L. Wideman

SPURRED by demands of a buoyant economy for mineral products, output from mines in the United States established a new record. Removal of waste material, necessary for the extraction of economic minerals, kept pace with mine production. Earth moving by these two activities exceeded 3 billion tons, an increase of 5 percent over that of 1963. Crude materials from which metal or nonmetal products were derived accounted for 75 percent of the total. The remainder, mostly worthless, was classified as waste. Changes in the minerals industry result from many causes. Technological trends and labor productivity are among several significant and interrelated indexes that assist in the analysis of the changes. Therefore, a. study of productivity is helpful in measuring technological growth in mining. Concepts of productivity tend to vary with the purpose for which the term is used; frequently, productivity is expressed in terms of units of output per unit of labor, such as tons of ore per man-hour or man-shift. Comparisons of levels of productivity for a group of products are usually made using composites of output. Data for all metal and nonmetal mines except gold, silver, mercury, platinum metals group, and sand and grave were used to compile the composite for determining productivity for 1960-64. Copper ore, iron ore, and phosphate rock are mined mainly by surface methods, but characteristics of the deposits and differences in processing the crude material affect production of the commodities. Therefore, productivity data for these selected segments of the minerals industry reflect the influence of physical conditions on the exploitation of them.

Jan 1, 1965

By D. J. Bauer

Liquid-liquid extraction techniques were investigated by the Federal Bureau of Mines for the fractionation of rare-earth solutions. Separatory funnel work using tri-n-butyl phosphate (TBP) for extracting ceric nitrate from solutions containing sulfate ion resulted in almost complete extraction. Similar tests using primary amines for splitting trivalent rare-earth pairs and fractions gave promising results. The ceric nitrate extraction procedure was scaled-up by use of pressure-bubbler equipment, a series of spray towers for extraction, washing, and stripping. In this case only 84 percent ceric nitrate extraction efficiency was achieved. This work was done using dilute sulfuric acid for stripping.

Jan 1, 1960

By G. A. Crowder

Far infrared spectra, most of them in the region 15-200 microns and for both the liquid or solution state and for the vapor state, were obtained for twenty-seven compounds.

Jan 1, 1965

By M. F. Koehler

[THE LITERATURE contains relatively few thermodynamic values for interoxidic compounds, and these often are unreliable. This is especially true of data for ferrites and aluminates for which heat of formation determinations may involve extreme experimental difficulties. This report contains the results of new experimental work for obtaining the heats of formation of five ferrites (Ca2Fe2O5, CaFe2O4, MgFe2O4,, NaFeO2, and LiFeO2) and one aluminate (CaAl4O7), and a review and revision of previous similar work of this laboratory on five aluminates (Ca3A12O6,, 12/7 CaO-Al2O3, CaAl2O4, NaA1O2, and LiAlO2), The results for the 11 compounds are combined with entropy and high-temperature heat content data to derive tables of heats and free energies of formation (both from the oxides and from the elements) for the temperature range 298° 1,800° K, The relative stabilities of the compounds are discussed. The presented data all have application to ceramic reactions, and those for the calcium and sodium aluminates are applicable in considering soda-lime sintering processes for extracting alumina from silicate minerals such as day and labradorite.]

Jan 1, 1961

By R. V. Ramani, V. T. Burgos, J. A. McClay

Cost System The cost system reported here is a suite of computer programs which incorporates the logic and information flow structure as outlined in earlier chapters. Specifically, computer programs have been devel¬oped to: 1. compute labor, operating, and capital costs, 2. summarize cost and production data, and 3. compute the minimum acceptable selling price for coal. While the cost system can be executed independently, it is de¬signed primarily for use with the Master Design Simulator and there¬fore must conform to the overall system hardware. The computer model is written in Fortran IV for use with the IBM System 360/370 computers as well as with compatible units such as the Univac 1110 and CDC-6600. For ease in error detection and program modification, the model was constructed with a main routine and eight subroutines. The main routine reads and stores the data necessary for the cost computations and calls the subroutines in logical sequence. The subroutines perform the cost computations and data adjustments for reporting purposes. Each subroutine performs the cost computations for its particular com¬ponent of the cost cycle. The program operations are described in the following narrative outline. Control Subsystem As previously described, the main routine is a passive element, reading and storing input data and directing execution to the active subroutines for cost calculations. Figure 10 is a macro-flow diagram

Jan 1, 1975

By G. L. Oldwright, F. K. Shelton, W. E. Keck

"INTRODUCTION Zinc must be of high grade to satisfy the present demand. Even when the amount of premium paid is small, the purer metal as the buyers' preference. The following specifications for spelter were taken from the American Society for Testing Materials for 1927, Part I, pane 524. (The specifications for 1930, p. 582, are tile same.)Another specification for zinc of a much higher grade than any of the above has been established lately by the same society. The committee on zinc die-casting (Proc. Am. Soc. Test. Mat., vol. 31, 1931, p. 263) reached the following, conclusions: I. ""That the purest of zinc is necessary to produce stable zinc-base die castings, and as a result requested specifications for zinc spelter .with total impurities not over 0.02 percent."" Their tests showed that the die castings made of the purest zinc had the least elongation and the greatest tensile strength, and exhibited the least changes with temperature.Still more far-reaching claims are made for the properties of zinc containing over 99.99 percent metal. Zinc foil, for instance, may someday be made as a common commercial product. It would seem likely that the demand for zinc of high grades rill continue and that even purer varieties may be desired. This demand fits in with the modern trend in manufacturing plants of reducing the number of variables to a minimum by using pure materials, and of controlling the processing of metals during their various stages of fabrication by mechanical means instead of by expert laborers."

Jun 1, 1933

By J. E. Chilton

Regular monitoring for methane gas is required near working faces in gassy underground mines where the potential for methane ignitions is greatest. However, high concentrations of methane can also accumulate outby the face where methane levels are monitored less frequently. Wearing a personal methane monitor equipped with an alarm could protect persons working in these outby areas from injury or death due to methane ignitions. The National Institute for Occupational Safety and Health (NIOSH) has conducted studies to evaluate methanometers that could be used as person-wearable monitors. For the present study, seven different person-wearable monitors that are not currently approved for underground use were evaluated. This paper describes test procedures used to evaluate performance of methane monitors that could be used underground for continuous personal monitoring of methane. The information in this report provides data that allows the reader to make side-by side comparisons of these instruments.

By John Ward Smith

Methods for estimating the amounts of nahcolite, dawsonite, and the sum of these two sodium carbonate minerals from oil-yield assay data are developed and evaluated for Green River Formation oil shales from the saline section of Colorado's Piceance Creek Basin. Derived statistically, these estimation methods depend on the fact that these minerals yield water and gas measured during oil-yield assay. The estimation procedures yield values for nahcolite and nahcolite-plus-dawsonite of sufficient accuracy for stratigraphic plotting and correlation, whereas estimates for dawsonite are more generalized. However, resource estimates and reserve computations for both nahcolite and dawsonite accurate within 10 percent of the real value are readily available by summing the mineral amounts calculated by the procedures presented. These estimation procedures are applicable to oil-yield assay data on core samples from more than 30 coreholes which have penetrated the saline section of the Green River Formation in Colorado.

Jan 1, 1972

By D. R. Flinn

The Bureau of Mines has studied the electrochemical parameters important to the preparation of coatings of the platinum-group metals. Using molten mixtures of sodium and potassium cyanides in an inert atmosphere, techniques have been developed that permit the preparation of baths for platinum, rhodium, and iridium electrodeposition. Cyclic voltammetric and slow sweep rate linear polarization techniques have been utilized to determine optimum potential and current values for preparation of plating baths and for the electrodeposition of coatings. Techniques are described for the deposition of platinum and rhodium coatings at near 100 percent anode and cathode current efficiencies, and for iridium at approximately 80-percent efficiency. Palladium deposition from these molten cyanide baths remains un-satisfactory. The chemistry of the palladium-containing cyanide bath is discussed. Examples of scanning electron microscope photomicrographs of typical platinum coatings are presented. Techniques are described for the preparation of platinum coatings on large objects.

Jan 1, 1982

As shown in Table 9, consumption has risen steadily for the period November through April, reaching its highest level since June of 1974. Imports remained at a relatively high level in spite of decreased imports from Zaire and Belgium-Luxembourg. Award prices for cobalt sold by the General Services Administration on June 17, 1976 ranged from $5.058 to $5.41211 per pound of contained cobalt. The high bid was about $1 per pound above the current market price set by the major sales agent in the U.S. for cobalt on April 15, 1976. COPPER: Eight domestic producers on July 1 hiked refined copper prices by 4¢ to 74¢ per pound for cathode and to 74.625¢ for electrolytic wirebar. New York Commodity Exchange (COMEX) June pricing of prompt contracted copper averaged 70.6¢, with daily quotes registering between 67¢ and 72.5¢ per pound. In June, London Metal Exchange (LME) cash wirebar prices averaged 70.3¢, trading between a low of 65.5¢ and a high of 73.6¢. End of the month copper stocks totaled 108,758 short tons for the COMEX and 539,350 metric tons for the LME.

Jan 1, 1976

By R. V. Ramani, V. T. Burgos, J. A. McClay

Cost Data Library The data retained in the Cost Data Library is of a semi¬permanent nature in that it is held in storage for immediate use with the program although its contents may require periodic evaluation to maintain it in a current status. The library is composed of six arrays containing both technical and cost data. The following description of the library input system provides the information necessary to maintain an active storage file. Array POWERA: FORMAT (8F10.0) - contains the step groupings of the power rate schedule for power cost computations. Four input data cards are required to fill this storage area. Card Column 1 1 - 10 Demand in Kilowatts for the First Step of the Demand Rate Schedule 11 - 20 Demand in Kilowatts for the Second Step of the Demand Rate Schedule y 41 - 50 Demand in Kilowatts for Fifth Step of the Demand Rate Schedule 51 - 60 Maximum Demand Level for this Rate Schedule 61 - 70 Percent Power Factor for this Rate Schedule 71 - 80 Unassigned 2 1 - 10 First Step Demand Charge, $/Kw 11 - 20 Second Step Demand Charge, $/Kw 4¬ 41 - 50 Fifth Step Demand Charge, $/Kw

Jan 1, 1975

By Kathleen M. Kowalski, Audrey Podlesny

The Maslach Burnout Inventory (MBI) was administered and scored for 154 Mine Safety and Health Administration (MSHA), U.S. Department of Labor, employees who serve as accident investigators for serious accidents and fatalities as part of their job duties. The subjects responded anonymously during a workshop on stress. The subjects consisted of randomly selected individuals, representative of locations across the country and representative of all mining commodities: coal, metal, nonmetal, stone, and sand and gravel. The Maslach Burnout Inventory assesses three aspects of experienced burnout: emotional exhaustion, depersonalization, and reduced personal accomplishments. The average results of the scores for each of the three subscales fell in the moderate range for the study group of MSHA accident investigators. The scores within the moderate range show that the subject population was at the lower end of the range for emotional exhaustion and depersonalization, tending toward a lower burnout risk, while the group evidenced a lower sense of personal accomplishment in their jobs, indicating a higher risk for burnout. It is concluded that overall this group is at moderate risk for burnout, and the authors recommend follow-up with this population.

This report describes the new Bureau of Mines Core Repository System (CORES) and presents the methods for selecting, processing, and storing physical samples and descriptive data for future reference by earth scientists. The system preserves splits of chip samples and longitudinally sliced segments of core. A records retrieval system provides for storage of data on microfilm and magnetic tapes and uses the keysort parameters of location and commodity for the identification of data.

Jan 1, 1978

A computer program for the static load analysis of linear elastic structures is presented. It is the product of a two-year project for the development of a efficient program for the analysis of mine-type structures. The report is divided into two parts. The first part explains the general method of analysis, the computer program organization and the most significant numerical techniques used. The second part is a user manual for the computer program. The FORTRAN IV computer program deck and example problems were transmitted separately to the sponsor. Request for a copy of the program should be directed to the Bureau of Mines, Denver Mining Research Center.

Jan 1, 1972

By W. W. Adams

"Accidents at coal mines in the United States in September 1926 resulted in the loss of 170 lives, according to information furnished to the Bureau of Mines, Department of Commerce, by State mine inspectors. Of this number 125 occurred at bituminous mines and 45 in the anthracite field. As the bituminous output of coal for September was 48,976,000 tons, and the production of anthracite was 8,444,000 tons, the fatalities reported represented a death rate of 2.55 per million tons for bituminous mines and 5.33 for anthracite mines. The industry as a whole showed a fatality rate of 2.6 per million tons of coal produced in September 1925 the rate for bituminous coal mines was 3.29; the anthracite mines were idle in September last year due to a strike.During the first nine months of the present year 1,759 men have been killed by accidents at the coal mines throughout the United States, resulting in a death rate, per million tons of coal produced, of 3.76 as compared with 3.95 for the same period in 1925. Reports for bituminous mines alone showed a nine-month fatality rate of 3.53 which was about the same as the corresponding rate from January to September in 1925. The anthracite rate for the present year, however, shows a decrease of about 17 per cent; that is, the rate has declined from 6.36 to 5.28.Records covering the first nine months of 1926 show that 12 ""major"" disasters, that is, disasters in which five or more men were killed at one time, have resulted in the loss of 271 lives as against 10 disasters and 199 deaths in the corresponding months in 1925. The fatality rates for these disaster: alone were 0.579 and 0.465, respectively. One major explosion occurred at Tahona, Oklahoma, on September 3, 1926, in which 16 men lost their lives.An analysis of the principal causes of the 1,759 fatalities for the first nine months of the present year shows a reduction in the death rate as a whole and for falls of roof and coal and for explosives, but an increase in haulage, gas and dust explosions, and electricity. The comparative rates for these accidents were:"

Oct 1, 1926

By L. Cheng, M. S. Seehra, P. S. Raghoottama

The four major IR bands of a-quartz at 1080, 797, 693 and 488 cm-1 are studied at room temperature by FTIR-Photoacoustic Spectroscopy. Using Rosencwaig-Gersho theory, equations for the PAS signal q for the thermally thin and thermally thick cases are derived and it is shown how thin to thick transition occurs and leads to saturation as the sample mass is increased. For sample mass < 2 mg, q is proportional to sample mass thus defining the region for quantitative analysis. The dependence of q on the chopping frequency f is found to vary as q f-n with n ? 0.9 for quartz, in good agreement with the RG theory.

Jan 1, 1989

By Alla D. Mah

No experimental heat-of-formation value has been reported in the literature for cerium sesquioxide. The heat of formation of bismuth sesquioxide has not been determined in recent years, and the older value was subject to large uncertainty. Accordingly, the heats of combustion of cerium sesquioxide and bismuth metal were measured by the Federal Bureau of Mines. The heats of formation were: ?H°298.15 = -427.01 ± 0.70 kcal. /mole for cerium sesquioxide and ?H°298.15 = -137.16 ± 0.30 kcal./mole for bismuth sesquioxide. The free energy of formation was estimated for cerium sesquioxide and accurately calculated for bismuth sesquioxide. The data were compared with values in the literature.

Jan 1, 1961