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By L. J. Froisland

The U.S. Bureau of Mines conducted laboratory studies on sulfuric acid (H2S04) digestion of alunite [KA13(S04)2(OH)6] as a means for treating domestic deposits of this mineral. Digesting alunite ore in boiling H2S04 at concentrations of 88-wt-pct acid or higher breaks down the alunite and permits a convenient separation of potassium and aluminum. The digestion reaction is a complex sulfation reaction occurring in two stages. In this reaction, the potassium component extracts into the H2S04 for eventual recovery as potassium sulfate k2s04 in a separate unit operation. Aluminum is left as acid-insoluble aluminum sulfate [A12(S04)a], which can be extracted by a 95° C water leach. Additional purification of AI2(S04)a produced in this study is needed to meet cell-grade alumina (Al202) purity specifications. Extraction and separation of potassium and aluminum from the alunite ore were consistently above 90 pct.

Jan 1, 1989

By Louis C. Brichta

This report summarizes the progress made by the Federal Bureau of Mines in assembling and compiling a catalog of available logs of drill holes and maps of mine developments in the Tri-State Zinc-Lead District in northeastern Oklahoma, southeastern Kansas, and southwestern Missouri. It supplements an interim report (11)3/ published in 1955, and for convenience of the reader repeats much of the general descriptive matter pertinent to the district contained in that report. The work of procuring and recording the data was begun in August 1949 and was recessed in May 1959. The catalog preserves the records of accomplished explorations and mine developments in the district and provides a readily available source of information for individuals and firms interested in planning mineral explorations, Government agencies estimating of reserves of mineral resources, and the mining industry for general use.

Jan 1, 1960

By Russell. Paul L.

"INTRODUCTION Preliminary reports by Bureau of Mines engineers 3/ and by the Federal Geological Survey 4/ suggested that exploration would discover substantial reserves of minable ore in the Contact mine, Grant County, New Mexico. During February and March 1943, a sampling program was conducted on this property under the direction of the author. This was art of a general survey of the manganese districts of southwestern New Mexico.In its program of exploration of mineral deposits, the Bureau of Mines has as its primary objective the more effective utilization of our mineral resources, to the end that they make the greatest possible contribution to national security and economy. It is the policy of the Bureau to publish the facts developed by each exploratory project as practicable soon as after its conclusion. The Branch, Lowell B. Moon, chief, conducts preliminary examinations, performs the actual exploratory work, and prepares the final report. The Metallurgical Branch, R. G. Knickerbocer, chief, analyzes samples and performs beneficiation tests. Both these branches are under the supervision of Dr. S. Dean, assistant director. With respect to this report, special acknowledgment is due to C. H. Johnson, district engineer for New Mexico, and E. D. Gardner, regional engineer, and his staff, of the Central Region of the Bureau of Mines at the time of this work in 1943; also to Kenworthy, metallurgist at the Rolla. Mo., Laboratory of the Bureau of Mines, for work on beneficietion of the ore, and Sherman K. Neuschel, geologist of the Federal Geological Survey, for assistance in interpreting geological data at the project."

Oct 1, 1946

By G. L. Cook

The design of a dual-inlet system for a Consolidated model 21-103C mass spectrometer is described in detail. The system permits both high-mass and low-mass samples to be run by using a single instrument. The difficulties of using a single instrument for both purposes are given and a method of minimizing these difficulties through the use of the present design is discussed, After examining the experience of five years of use, the conclusions are that the bimodal operation is practical and the low-mass analyses had nearly the same precision as before the modifications to the instrument were made. In 1951, O'Neal and Wier.5/ published the first description of the modifications made to a mass spectrometer so that the spectra of hydrocarbons with molecular weights up to 600 could be obtained. Further discussion of the equipment of O'Neal appeared in 1953.6/ Also, Brown, Melpolder, and Young7/ described a parallel inlet system designed to reduce sorption effects at room temperature.

Jan 1, 1960

By Jeffrey Shawn Peterson

The testing procedures of the U.S. Mine Safety and Health Administration specify that intrinsic safety acceptance tests be conducted using a standard tungsten-cadmium electrode configuration in the break- flash apparatus. However, in realistic mining environments, other materials may be more likely sources of sparking. Information defining the probability of spark ignition between common materials such as aluminum, brass, copper, lead, tin, cold-rolled steel, and stainless steel is of more practical value in determining ignition hazards. The U.S. Bureau of Mines has completed an investigation of the influence of material on the ignition probability using the breakflash apparatus. By comparing ignition currents or ignition voltages corresponding to a probability of one ignition per thousand sparks to those found previously for cadmium, a margin of safety may be estimated for each material. This report presents the results of an investigation into the influence of disk electrode material on the probability of ignition.

Jan 1, 1992

By M. A. Lucas

The Bureau of Mines has developed a computerized mathematical model to predict the distribution of accessory elements throughout a metallurgical process. The model can be used to determine process conditions that effect better accessory element control consistent with continued high primary metal recovery. The model presented is specific for determining the bismuth distribution in lead smelting but can be adapted to most extractive metallurgical processes. Thermodynamic, kinetic, and process parameters form the base for the model. Its logic and structure are described in detail.

Jan 1, 1983

By D. G. Foot

The Bureau of Mines devised a direct flotation method for recovering potash from carnallite (KC1?MgC12?6H20) ore characterized by a high content of water-insoluble impurities. The method includes (1) a decomposition leach of the carnallite, (2) flocculation-depression of the insoluble slimes, (3) potash rougher, cleaner, and recleaner flotation, and (4) final product leaching. The technique eliminates the necessity for removing the water-insoluble slimes by mechanical or flotation de-sliming. Laboratory results demonstrated that the direct flotation procedure, when compared with conventional techniques, yielded equivalent or improved flotation results with equal or less reagent consumption. Locked-cycle testing of the direct flotation method recovered 87.8 pct of the potassium in the flotation feed in a final product containing 60.6 pct K20. A flowsheet incorporating the carnallite leaching-potash flotation procedure is presented.

Jan 1, 1982

By McHenry Mosier

Mercury is one of the strategic metals the supply of which has been raised from critical uncertainty to more than enough for essential demands. Work by the Bureau of Mines has contributes substantially to increased production of mercury in the United States and to consequent accumulation of Governments stock. Other contributing factors were higher prices for mercury and Government loans to operators. The Bureau has undertaken 15 exploration projects, 13 of which have been completed. This work comprised 40,307 feet of drilling arid 35,082 linear feet of sure ace trenching and has indicated commercial ore containing 37,400 flasks of mercury and marginal ore contain¬ing 29,200 flasks - a total of 66,600 flask , equivalent, respectively, to domestic production at 50,000 flasks per year for 9 months , 7 months, and 16 months. Early in 1944, as Government stocks had become adequate, domestic production was gradually curtailed cancellation of Government contracts for the purchase of mercury and Government control of labor and operating supplies.

Jan 1, 1944

By A. J. Kraemer

For a number of years the Bureau of Mines has conducted semi-annual survey to determine the changes in the characteristics of the rotor gasoline being sold in the United States. Certain cities have been decided upon as points of origin of samples. Tare choice of these cities has been governed by their situation as the representative of a more or less definitely bounded marketing territory. Samples have been taken on or about the fifteenth day of January and July of each year. In the collection of the samples an attempt has been made to get a representation of the important types of motor fuel being sold, and also to tame into consideration the proportion of tie total consumption that is supplied by the different marketers. It is therefore felt that the survey affords a reliable indication of the quality of the gasoline being sold throughout the United States at the time of sampling. The figures in Table I, below, were obtained by averaging the end points of the least volatile and most volatile samples of gasoline. For example, of 850 samples analyzed in 1919, the 10 per cent (85 samples) having the highest end points, and the 1C per cent having the lowest end points were averaged. These averages are represented in the table as the "Maximum 10 per cent" and the "Minimum 10 per cent", respectively. The same scheme was used in the succeeding surveys.

Jan 1, 1925

By Manuel Gomez

The mean and the standard deviation were used to describe general sulfur and ash populations as well as specific populations of these variables from one coal seam. Both the mean and the standard deviation were incorporated in the exploration process to determine the number of drill cores necessary for seam evaluation and to guide the sequential drilling plan. Probability regions were computed to establish a basis for predicting probable ranges of average sulfur and ash concentrations that may be expected upon continued or future drilling. A computerized plot program was utilized to interpolate sulfur and ash concentrations between grid points. The plot program, which is essentially a moving average technique, permits a rapid evaluation of sulfur, sulfur forms, and ash spatial distributions as a drilling program progresses sequentially. This information, in the form of contour plots, can be made available to both the mining engineer and the fuel technologist in advance of mining to outline reserves, to improve selective mining, and to anticipate preparation facilities.

Jan 1, 1972

Reduce worker exposure to respirable dust without interfering with bag-filling operations. Approach A dust control hood was developed which contains and captures dust close to its source and prevents it from entering the bag-filling operator's work place. How It Works A sheet metal hood is placed around the nozzle of the bag filling machine. The hood is connected through ducts to the plant exhaust ventilation system. Air pulled into the front of the hood and around the sides of the bag picks up dust generated inside the hood, and carries it to the dust collector. The size of the hood can be adapted to fit most fluidized valve-type bag-filling machines. The height of the hood depends on the bulk density of the product and weight of the bags being filled. The 14-inch-width of the hood allows it to be used on multi-nozzle baging machines spaced 16 inches on center. Only 2/3 of the bag is actually within the hood, and this allows easy operator access for placing the bags on the nozzle.

Jan 1, 1978

By W. E. Dennis

"INTRODUCTION The strategic importance of zinc warranted investigation of the Silver Eagle zinc prospect, which was first examined by an engineer 3/ of the Bureau of Mines in January 1943.From October 12, 1943, to March 16, 1944, the Bureau explored the deposit by trenching, core drilling, and sampling to establish the amount and grade of ore and to test for the presence of sulfide-ore minerals at depth.ACKNOWLEDGMENTSIn its program of exploration of mineral deposits, the Bureau of Mines has as its primary objective the more effective utilization of our mineral resources to the end that they make the greatest possible contribution to national security and economy. It is the policy of the Bureau to publish the facts developed by each exploratory project as soon as practicable after its conclusion. The Mining Branch, Lowell B. Moon, chief, conducts preliminary examinations, performs the actual exploratory work, and prepares the final report. The Metallurgical Branch, R. G. Knickerbocker, chief, analyzes samples and performs beneficiation tests. Both these branches are under the supervision of Dr. R. S. Dean, assistant director."

Oct 1, 1946

By M. Kanefsky, A. Q. K. Rajput

Two channel polarity coincidence and polarity difference statistics are analyzed. The signal, common to both channels, consists of sinusoidal bursts where the exact frequency of the signal is nearly known, but other parameters such as amplitude, phase, and pulse starting time are unknown. The noise inputs are dependent, narrow band, Markov processes. It is shown that the performance depends not only on the signal uncertainties but on the precise shape of the cross-correlation functions between the noise inputs. By using two polarity difference statistics in addition to the polarity coincidence statistic, it is shown that the decrease in performance, as well as the cost of hard limiting due to correlated inputs, can be made small.

Jan 11, 1981

By T. F. Dumm, O. Trass, V. R. Koka, L. G. Austin

"The size distributions of carefully screened 2 size fractions of ground materials were determined using a Microtrac laser dif-fractometer. The size distributions were fitted to the empirical function P(x) = 1/[1 + (x50/x)1] where P(x) is cumulative mass fraction less than Microtrac size, x. The standard deviation of A for a 50 second test time was approximately 0.5, so that seventeen test times give a mean with an estimated error within t 0.25 (95% confidence level). Values of were 5.44, 4.82, 4.40 for a coal ground under different conditions, indicating statistically different shape distributions; the average value for mica was 2.91 owing to the high aspect ratio of the particles. The ratio of x50 to the geometric mean sieve size was 1.2 for the coal and 0.70 for mica.1 IntroductionKoka and Trass have presented evidence [1,2] that materials ground in the Szego mill [3] give different shapes depending on the milling conditions. The variations in shape were deduced qualitatively by viewing SEM photomicrographs of selected 1/2 screen fractions. This paper quantifies their observed differences in shape by using measurements of the size distributions of screen fractions examined in a laser diffractometer [4] (Microtrac, Model 7991). The basic concept is that particles of 'a given ""screen"" size will give a wider distribution of ""Microtrac"" size when the particles are flaky with high aspect ratios, and a narrower distribution when the particles approach the cubical and spherical geometries.2 TheoryAustin and Shah [5] have shown that coal screened within a 1. 1/2 upper-to-lower sieve size range will give rise to a much wider distribution of Microtrac size. They found that the screen interval of irregular fragments of comminuted coals or quartz gave Microtrac size distributions which could be described by the simple function"

Jan 1, 1988

By A. J. Kraemer

The Bureau of Mines for a number of years has been carrying on an investigation of properties of crude oils from producing fields in the United States and has published a series of reports on different fields, including oil fields of Texas3. Production Data The Spindletop field was discovered in 1901 when the pay sand was found at deaths of about 800 feet. During the following twenty-five years a number of attempts were made to find a deep productive sand. All attempts sere failures until a roll drilled by the Yount Lee Oil Company found oil late in 1925. An intensive drilling campaign began at once, and the production of the Spindletop field increased to a daily average of 93,217 barrels in September, 1926; the present production is estimated at 66,000 barrels doily. Tile following table taken from the Oil and Gas Journal for February 10, 1927, shows the daily average and the total production by ninths for 1926.

Jan 1, 1927

By Nicholas Kyriazi

A performance comparison of 14 rescue breathing apparatus was undertaken as an assessment of past and present worldwide technology. Rescue breathing apparatus are self-contained, closed-circuit breathing apparatus used for entry into areas having atmospheres that are immediately dangerous to life and health. Apparatus tested were the Biomarine BioPak 45, 60, and 240; the Draeger BG 4 and BG-174A; the Litton LITPAC II; the MSA Custom 4500 II Air Mask, Chemox, and McCaa; the Sabre Selected Elevated Flow Apparatus (SEFA); the Scott Rescue-Pak; the Siebe Gorman Aerorlox and Proto Ten; and the SurvivairLP-120. The apparatus were tested on an automated breathing and metabolic simulator at the Pittsburgh Research Laboratory of the National Institute for Occupational Safety and Health (NIOSH). Physiological parameters monitored during the testing were average inhaled CO2 and O2, minimum inhaled CO2, inhaled wet-and dry-bulb temperatures, and peak inhalation and exhalation breathing pressures. The metabolic demand on the apparatus was 1.35 L O2/min for most of the test with two 5-min intervals of 2.5 L O2/min, the first beginning 10 min into the test and the second beginning 10 min before the end of the rated duration of the apparatus. Results presented include apparatus service life and test-averages of monitored physiological parameters. Schematic drawings and photographs of the apparatus are also included. The Draeger BG-174A and BG 4 had the highest durations—295 and 291 min, respectively. The BG 4 hadthe lowest minimum inhaled CO2 levels, attesting to the effectiveness of its CO2-absorbent canister. The SabreSEFA had the lowest average inhaled CO2 levels, due mostly to the apparently low-dead-space mask andnose cup. The MSA Air Mask, the only open-circuit device tested, had the lowest wet- and dry-bulb temperatures, with the liquid-O2-source Siebe Gorman Aerorlox having the next lowest temperatures. The only apparatus with a CO2-absorbent not in a packed-bed design, the BG-174A, had the lowest exhalation pressures. The BG 4 had the highest level of positive pressure, with the Biomarine BioPak 60, Survivair LP-120, SEFA, and Litton LITPAC II nearly as high. The BG 4 had the lowest pressure swing, with the SEFA a close second.

Jan 10, 1999

By D. E. Hirsch

The Bureau of Mines has developed a systematic procedure for separation, characterization, and semiquantitative analysis of high-boiling (350° to 550° C) distillates of crude oils. Isothermal and molecular distillation were used to prepare the 370° to 530° C distillate of Recluse, Wyo., crude oil. The distillate was separated into fractions by chemical treatment, silica-alumina gel adsorption, and gel permeation chromatography (GPC). The fractions were analyzed by use of GPC correlations and mass and nuclear magnetic resonance (NMR) spectrometry. The increased knowledge of petroleum composition obtained from the data will contribute to improved petroleum processing and utilization and energy conservation.

Jan 1, 1974

By H. M. Smith

In studying the chemistry of lubricating-oil fractions from so-called ?paraffin-base? crudes, one of the first requisites is a method for the separation and removal of waxy material. A method utilizing solvents for this purpose is described in this report, together with preliminary experiments with solvents that led to its development. The solvents actually used are secondary butyl alcohol, acetone, and mixtures of these.. Isopropyl alcohol was also studied. Preliminary Experiments In previous work on "intermediate-base" crude oil, following the work of Wyant and Marsh acetone had been used for laboratory separations of oil and wax. Then acetone was tried for the separation of the waxes and oils of "paraffin-base" crude, the volume of acetone required (80 parts to 1 part of oil) was found to be too great for large-scale work. For this reason the effectiveness of other solvents was studied; the separation by acetone, however, was used as a standard.

Jan 1, 1927

By Charles L. Kimbell

In broadest overview, UN global industrial production indicators released and shown in table 2 suggest that the extractive sector of the world's mineral industry in aggregate registered a very slight upturn in 1991 relative to its 1990 performance. It also shows a continued rebound in the industry from the recessionary period of the mid-to late-1980's. These same indicators as calculated in late 1991, however, reflected a very minor downturn in extractive mineral industry operations between 1989 and 1990. This latter downturn represented a notable revision from the data reported in the immediate previous edition of this chapter, which suggested a tiny upturn. The apparent slight 1991 upturn in extractive sector industrial output generally was not mirrored in the performance of the processing sectors of the global mineral industry. Although the aggregate index for the chemicals, petroleum, coal, and rubber products manufacturers (see table 3) showed a notable gain in 1991, similar indices for nonmetallic mineral products and for base metals registered declines between 1990 and 1991. Examination of regional performance indices shows that the difficulties experienced in 1990 in maintaining output levels within the countries that formerly constituted the CMEA were reinforced by trends toward reduced gains in output levels, if not actual reductions in output, in several other areas. Generally speaking, the traditional developed market economy countries recorded downswings in overall industrial activity in 1991, particularly after midyear, whereas developing market economy countries logged gains. The developed market economy country downturns, however, were not nearly as significant as were the downturns recorded for the former centrally planned economy states - those that before 1992 were either constituent Republics within the U.S.S.R. or the latter's CMEA partners.

Jan 1, 1993

By John Taber, Robert D. O'Brien

"INTRODUCTION The Bozeman corundum deposit was first examined in May 1944 by an engineer of the Bureau of Mines. In August 1944, the property was re-examined because of a sharply increased war demand for corundum. A small program of trench exploring was undertaken after the second examination. The work was started in October 1944 and was completed in December 1944. This report presents the essential data obtained by the exploratory work.ACKNOWLEDGMENTSIn its program of exploration of mineral deposits, the Bureau of Mines has as its primary objective the more effective utilization of our mineral resources to the end that, they make the greatest possible contribution to national security and economy. It is the policy of the Bureau to publish the facts developed by each exploratory project as soon as practicable after its conclusion. The Mining Branch, Lowell B. Moon, chief, conducts preliminary examinations, performs the actual exploration work, and prepares the final report. The Metallurgical Branch, R. G. Knickerbocker, chief, analyzes samples and performs beneficiation tests.The field work on the Bear Trap project was supervised by E. W. Newman, district engineer Montana District office. The microscopic examinations and. the grid grain-count analyses of the samples and the beneficiation tests were made at the Bureau's laboratory at Salt Lake City, Utah, under the direction of S. R. Zimmerley, chief, Salt Lake City Division, Metallurgical Branch."

May 1, 1947