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By J. H. East

Potash is one of the essential chemicals used in fertilizing soil deficient in natural minerals . Europe uses a large tonnage of potash in the form of easily soluble salts , and this is particularly true of those countries where the natural minerals in the soil have been exhausted owing to intensive cropping of the land . The application of potash to the soil in these countries is essential if normal crops are to be obtained ; during the war , some European countries were unable to obtain sufficient potash , and productivity of the farming areas declined seriously . • The largest -known deposits of potash in the world ; with the possible. exception of Russia , occur in Germany , and the German output of processed salts constituted about 65 percent of world production prior to the war . The German potash-plant installations are large , modern , brick and steel construction and apparently built for a planned operation of many years . Two districts produced approximately 80 percent of the German potash; the Werra -Fulda district , near Vacha , had the largest production , and the Sudharz district , near Nordhausen and Sonderhausen , was second . (Fig . 1. ) Hannover and Stassfurt were two smaller producers . Potash fertilizers are rated in terms of potassium oxide (K20 ) . The usual basis for calculation of production or application of the salt is to reduce the potash content to 40 percent K₂0 .

May 1, 1947

By M. J. Pazuchanics

This U.S. Bureau of Mines report presents results from an ongoing investigation of the use of adaptive signal discriminating methods to distinguish between cutting coal and cutting mine rock. Bit-cutting forces and tool vibration were measured in the laboratory as a linear-cutting apparatus (LCA) made constant-depth cuts in coal, sandstone, and shale test specimens. A portion of the collected data has been analyzed and some preliminary results are given here. The influence of data bandwidth, data window size, number of signal features, and voting among classifiers on classification performance are noted. Results to date, based on ideal-cutting conditions and simple geologic materials, indicate that of the four classifiers tested there appears to be no single best classifier. Usually, classification accuracy showed slight improvement as the number of features considered for classification increased. The highest classification accuracies were achieved when voting was conducted among classifiers followed by voting among force components.

Jan 1, 1991

By R. B. Stroud

This report, part 3 of a series, describes and gives results of field. investigations by the Bureau of Mines on manganese resources of the Batesville district, Arkansas, from July 1956 through June 1961. The purpose of the Bureau's work was to evaluate the manganese potential of the district in fur- therance of the Government's program with respect to domestic resources of critical and strategic minerals. The work comprised areal reconnaissance, mapping, churn and core drilling, and sampling. In more recent years, the investigations were confined to manganiferous limestone, which constitutes a significant potential resource of manganiferous material. The resources of manganiferous material in the district are inferred to be on the order of 198 million long dry tons averaging between 4 and 5 percent manganese.

Jan 1, 1964

By R. V. Higgins

This report presents the results of a study of water injection in the HX sub-pool fault block V-B, in the Upper Terminal zone, Wilmington field, California, and is based on data obtained to May 1957. An earlier report3/ describes the results of gas injection in part of the field. The principal purpose of the pilot flood was to determine whether a sand having a permeability of 1,200 millidarcys and containing oil having a viscosity of 17 centipoises could be waterflooded effectively. The results of a preliminary study by engineers of the Long Beach Harbor Department of oil recoveries from areas where encroaching edgewater was active and the results of an independent study by a consultant retained by the Long Beach Harbor Department were favorable to a trial waterflood. After these preliminary studies, a detailed petroleum-engineering exam-ination was made of the technical details. As a result, a peripheral flood was started in June 1953. The peripheral flood was deemed desirable because the producing wells are bottomed a short distance from the edgewater. The HX subpool was selected for the pilot test because it is an isolated section of the Upper Terminal zone and is separated from the adjoining pools by faults on the east and west and by edgewater on the north, south, and west. Several petroleum-engineering methods were applied to evaluate the performance of the waterflood, and all showed that injecting water stimulated oil production.

Jan 1, 1958

By C. L. Brown

The frequency of mine fires during recent years, with an apparent increase in recent months, has focused attention on the necessity of reducing this hazard by every means possible. Investigation reports are available on 51 mine fires of electrical origin between August 15, 1949, and August 16, 1954. Nine other fires in the same period were suspected as being of electrical origin. Every mine fire is a potential hazard to underground workmen; it is remarkable that only six lives were lost as a result of these fires, since the injury list was very high. Modern mining methods, with increased power demands and extended distribution systems underground, involve greater electrical hazards and possibilities of costly production delays as a result of inadequate electrical service. Improvements in electric-power-distribution facilities in many underground coal mines is desirable. The purpose of this paper is to show the need for this improvement as revealed by studies and investigations of electric-power-distribution systems representative of those in a large number of coal mines.

Jan 1, 1955

By Louis A. Panek

Roof bolting has been known for many years, although the practice had very limited application before 1948. Since then, bolting has been introduced as a systematic method of support in more than 700 coal mines and more than 200 noncoalmines and other underground openings in rock. By far the greatest number of bolts are used to support bedded roof. This is largely because of their use in coal mines, although roof bolts are used in mining bedded deposits of all kinds -potash (New Mexico), trona (Wyoming), and ores of iron (Alabama), lead (Missouri), uranium (Utah), lead-zinc (Utah), and copper (Michigan and Arizona). Thus, bolting has been successfully employed to reinforce bedded roof under a wide range of conditions despite the limited knowledge of the principles involved. This report develops the basic principles of bolting bedded roof based on elementary beam theory and on the results of tests intended to prove or disprove certain fundamental premises. Specifically, the objectives were to gain an understanding of the function of the bolts and the behavior of bolted roof and to establish standard bolt patterns. A combination of theoretical and experimental analysis was employed. The experimental method consisted of testing mine -roof models in a centrifuge. The models, the test procedure, and the model-prototype relations are described in a companion report (1)2/. A second companion report presents a method for designing systems of vertical bolts to reinforce bedded roof (2).

Jan 1, 1956

By M. J. Kovalik

The effect of oxidation by air at temperatures ranging from 200° to 390° C on the change of chemical and physical properties of Pittsburgh-bed coal was studied as a function of processing time and temperature. The goal was to prepare a nonagglomerating fuel from a strongly coking coal for use in continuous carbonizing processes and in fixed-bed gasifiers. The oxidized coal was carbonized in a bench-scale apparatus, and the coke strength was evaluated in a Roga tumbler. Strength of the coke was progressively reduced with time of oxidation until the coking power of the coal was apparently destroyed. Time requirements to obtain an essentially nonagglomerating product were inversely related to processing temperature. Gaseous products released from the coal during oxidation reduced the yield of the desired nonagglomerating product, which decreased with time of oxidation at constant temperature and with increase in processing temperature at equal time. Oxidation at a temperature slightly above the lower limit of the plastic temperature range of Pittsburgh-bed coal was most effective because of the short processing time required and moderate processing losses.

Jan 1, 1963

By Terry J. Close

The Anaconda Pintlar Wilderness has a significant mineral resource potential. Five deposits have resources totaling about 180,300 tons (163,600 t) containing silver, copper, lead, gold, and zinc. Another 11, not sufficiently exposed to allow resource estimates, may have additional mineral potential. No placer deposits are indicated. There is little potential for the production of sand, gravel, or stone; alternate sources are closer to markets. No oil, gas, uranium, or geothermal energy sources are known to be present.

Jan 1, 1982

By M. J. Dailey

This paper is one of a series being prepared by the United States Bureau of Mines on mining practices, methods, and costs in the various mining districts of the United States. The property of the Silver King Coalition Mines Co. is situated in the western past of the Park City mining district, Utah, about 1 ½ miles southwest of the town of Park City, The elevation at the collar of the main shaft is 8,137 feet above sea-level.

Jan 1, 1930

By E. J. Murphy

The Bureau of Mines developed a fast, reliable modification of the Griess-Ilosvay procedure suitable for field analysis for NO2 in the fumes from explosives. Known concentrations of NO2-air mixtures were analyzed for the nitrous acid or nitrite formed in the reaction with three Griess-Ilosvay-type reagents by diazotizing and coupling. Comparison was made of the Rider-Mellon, Saltzman, and Patty-Petty procedures; the three procedures are in agreement if sufficient time of contact between NO2 and the reagents is allowed. In experiments to obtain an accurate factor for converting NO2 to nitrite, overnight contact was allowed in order to be sure conversion was complete. The factor was found to be 75 percent with a standard deviation of ±3.2. Low and erratic results were found using either the Saltzman or Patty-Petty reagents as absorbing liquids unless several hours' contact was allowed. If dilute NaOH solution was used as the absorbing liquid instead of a Griess-Ilosvay-type reagent, 92 percent of the overnight conversion factor was found after a 3-minute shaking time and a la-minute standby time. The Saltzman reagent was preferable for fieldwork with the dilute NaOH solution as the absorbent because of its easy application, rapid reaction, and intense color even at low NOB concentrations.

Jan 1, 1967

By Ad. Breyre

For more than 20 years, Belgium, leading all the coal-mining countries, has made increasing use of sheathed explosives, which wore first suggested by the late E. Lemaire, predecessor of the author gas Director of the Institut National des Mines. It appears to the author that it will be valuable to show how the use of sheathed explosives has developed in Belgium, how the various difficulties encountered in their manufacture have been overcome gradually, and the tyros of sheathing that have survived and the reasons for their survival.

Jan 1, 1940

By Jack G. Croeni

A study was made by the Bureau of Mines to determine the influence of high energy-rate deformation on the structures and properties of low-carbon steel, stainless steel, titanium, titanium-6 percent aluminum-4 percent vanadium, beryllium, molybdenum, and tungsten. The purpose of this study was to determine relative formability, the effect of energy and temperature on metalworking parameters and resulting structures, and the properties of materials formed by this technique. Forming techniques were limited to upset forging and direct extrusion on pneumatic-mechanical forming machines. Results show that considerable grain refinement can be achieved by careful control of deformation and forming temperature by high energy-rate techniques. Significant improvements in strength were observed as a result of this refined structure. Approximate deformation resistance as a function of temperature was determined for a variety of materials.

Jan 1, 1966

By D. A. Lucero, J. E. Brockmann, L. A. Mondy, K. L. Rubow, D. J. Rader

"Department of Mechanical Engineering, University of Minnesota, Minneapolis, MNExperimental and correlated stage responses (the fraction of particles entering an impactor that are collected on a stage) are presented for the Andersen Mark III and Marple personal cascade impactors. The impactors were operated upright and fully assembled so that interstage interference and wall losses could be properly studied. The observed stage responses showed maxima that fell significantly short of unity, meaning that a monodisperse aerosol is never collected exclusuvely on one stage, but is distributed among several stages and internal losses. Correlations for the stage responses are presented so that the experimental results can be used to determine size distributions with available data-inversion algorithms. Simulations with log-normal distributions show significant differences between dpa50 histograms and the more accurate distributions that result by taking the response functions into account.Cascade impactors are widely used for the measurement of aerosol size distributions; their ruggedness and simplicity of operation make them an attractive choice for a variety of environments. In one common application, the aerosol of interest is drawn through the impactor, and the amount deposited on each stage is determined gravimetrically. The primary objective is to extract as much information as possible about the initial size distribution from the resulting set of weights. Unfortunately, the reconstruction of contin-uous size distributions from finite data sets is an ill-posed problem. Not surprisingly, a variety of such reconstruction techniques are presently in use; the success of each method depends on the particular nature of the aerosol sample and the instrument response.Inversion of impactor data by any of these techniques requires that the response functions for each stage be known. The stage response function gives the fraction of particles entering the impactor that deposits on that stage. Values of the response function range from zero to one, and depend on impactor operating conditions (e.g., geometry, flow rate, and gas properties) and particle properties (e.g., diameter, density, and shape factor). As interstage interferences and particle losses will affect each stage's response, experimental determination of stage responses should be made for fully assembled impactors. Unfortunately, impactor stage response functions are rarely reported; rather, single-stage efficiency curves are given that provide an incomplete description of impactor performance.This paper presents experimental stage responses for two fully assembled cascade impactors: the Andersen Mark III and Marple personal impactors (model 298, Andersen Samplers, Inc., Atlanta, Ga.). These calibrations were performed with monodisperse liquid droplets for both impactors and also with monodisperse solid spheres for the Marple personal impactor. The calibration results for the Mark 111 impactor presented here have been previously reported in the response-function format (Rader et al., 1989). The calibration results for the Marple personal impactor, however, were originally presented in the single-stage efficiency for¬mat (Rubow et al., 1987) and have been reanalyzed in this work. Losses within both impactors are considered, and their treat¬ment within data inversion techniques is dis¬cussed. In addition, correlations for each impactor's response functions are presented so that these calibration results can be easily included in data-inversion algorithms. Size distribution inversions using these response correlations are compared with the standard cut-point method for two lognormal test dis¬tributions."

Mar 1, 1992

By D. J. Parker

Ability to signal the hoisting engineer in shaft mines is of utmost importance from the standpoint of safety and economy. The problem of signalling from the cages and especially from the moving cages has received too little attention from mine operators; however, this problem has been given considerable thought and attention by at least one large metal-mining company in Utah which has devised successful, economical, and safe systems of signalling from the cage whether it is moving or at rest. A Report of Investigations on "Methods used in Utah for signalling mine hoists from moving cages," by C. A. Allen, then a metal-mining engineer in the Bureau of Mines, was issued in June, 1920. As this report contains interesting history of systems of signalling from moving mine hoists, and describes several systems then in use, it is here quoted in full.

Jan 1, 1929

By R. V. Ramani, P. M. T. White, D. Sutton

1.1 General The examination and evaluation of a mineral deposit to determine whether or not it can be profitably exploited entails many factors unrelated to the physical nature and intrinsic worth of that deposit. Nevertheless, geology and geologically related factors have great bearing on the economic potential of the deposit. This is only natural because the deposit owes its existence to these factors. This is even more so in underground mines where the whole system is a geologically enclosed one. Geology plays a major role in at least four phases of a mineral venture. Firstly, it acts as an indicator of the existence of parti¬cular minerals. For example, it is inconceivable that a sedimentary coal deposit would exist in a granitic batholith or stock, or that a sandstone would host primary copper or nickel sulphides. Further, the positional relationship of different rock types may be significant in locating deposits such as replacement zinc and copper sulphides in limestones which have been intruded by igneous rocks. Thus, geology is important in the exploration phase of a mineral deposit. Secondly, once potentially valuable minerals have been discovered, knowledge of geology plays a significant role in determining the dis¬tribution, grade and extent of the mineralization. Controls on mineralization include one or all of those related to structure, rock type, sedimentary features, post-depositional redistribution, etc. Con¬sequently, in order to effectively evaluate a deposit in terms of

Jan 1, 1974

By E. A. Pelczarski

Initially, the objective of this contract was to develop a PWSCSR that could meet proposed criteria (that were different from 30 CFR 11(Title 30 of the Code of Federal Regulation part II) and that would be less than twice the size and weight of a filter self rescuer. This objective was met. Consequently, the original contract was extended to develop a PWSCSR that would meet existing CFR-30 criteria within the same size and weight constraints. This resulted in the development of a PWSCSR (the SR-100) that received NIOSH/MSHA approval (TC-239). This report presents a historical discussion of the design and development of the SR-100 as developed by CSE Corporation under Bureau of Mines contract number H0368013. The technical parameters and the test results of NIOSH/MSHA 30 CFR 11 certification are also presented.

Jan 1, 1990

By L. A. Neumeier

The Bureau of Mines evaluated the properties of a Zn-0.75 pct Cu-0.12 pct Ti alloy extruded at temperatures between 400° and 720° F. The extrusions were made with a reduction ratio of 28-to-l and at relatively slow speed. Rod was also extruded at 560° and 640° F with a reduction of 255-to-l. With increased extrusion, temperature, extrusion pressures decreased substantially and creep resistance of the rod improved significantly. Coefficients of thermal expansion were low in the long rod dimension. Microstructures, hardness, and tensile properties were also evaluated, and a limited evaluation was made of bend ductility at 32° F for the rod extruded with the 255-to-1 reduction.

Jan 1, 1969

By Robert E. Barieau

General expressions for evaluating practically all the thermodynamic properties of a fluid from a single equation of state are derived. Most of the formulas are expressed in terms of the compressibility factor, with this factor being an explicit function of the temperature and the molal density. Similar expressions are given using reduced variables.

Jan 1, 1967

By John B. Gayle

[The coking time exerts a Considerable influence on the throughout of a coke oven, and for this reason a large number of papers dealing with the relation between coking tine and the different operating variables have been published. Although all of the factors known to ink influence the coking time have been studied, agreement leas not boon reached on several questions, 3/4/ and it appears worthwhile to evaluate any data that become available during investigations of the carbonizing properties of various oafs and coat blends, this report, therefore, includes a Study of the relation between coking lime and flue temperature and represents the second phase of overall investigation ion of factors influencing the coking time in slot-type ovens.]

Jan 1, 1956

By H. A. Watson

The introduction and use of synthetic materials in various applications may lead to potential hazards from toxic, gaseous, decomposition products if these materials are subjected to conditions abnormal to their intended use, such as high temperatures or burning from accidental causes. This report covers an investigation of such possible hazards from toxic gases produced by the burning or thermal decomposition of some low-density, expanded, synthetic materials, three of which consisted of polyvinylchloride and one of acrylonitrile. In the production of certain expanded plastic materials, Chemical blowing agents frequently are used to produce a cellular structure. One of these blowing or foaming agents contains azo-bis-isobutyronitrile, which is designated in this report as PN. Information indicates that a product of decomposition of this blowing agent, formed in the blowing operation, is tetra-methyl-succino-nitrile, designated as TSN, Which is significantly toxic. Decomposition of the blowing agent, with release of its azo nitrogen, is represented by the following reaction:

Jan 1, 1951