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By F. P. Haver

A procedure is described for recovering both lead and sulfur from galena flotation concentrate, comprising the following steps: (1) Aqueous oxidation of the concentrate, using ferric sulfate to convert lead sulfide to sulfate and to give elemental sulfur; (2) regeneration of the ferric sulfate by electrolysis in a diaphragm cell; (3) treatment of the leach residue with ammonium carbonate solution to change the lead to an acid-soluble form and to produce ammonium sulfate as a byproduct; (4) solution of the lead carbonate in hydro-fluosilicic acid followed by electrolysis to recover the lead as metal and regenerate the acid; and (5) extraction of the elemental sulfur from the final residue with an organic solvent. About 90 percent of the lead can be recovered by the above method as 99.9-percent-pure metal, together with two-thirds of the sulfur--half in the elemental form and half as ammonium sulfate.

Jan 1, 1970

By Rudolf E. Greuer, Linneas W. Laage, Xinton Chang

INPUT FORMAT INSTRUCTION FILE FOR PROGRAM MFIRE GENERAL RULES FOR DATA INPUT: $THERE IS NO NEED TO DISTINGUISH INTERGER AND REAL NUMBERS. $ $ SYMBOLS FOR NUMERICAL INPUT INCLUDE THE FOLLOWING $ $ 1234567890 -+BLANK $ $ * FREE FORMAT IS ALLOWED. COMMA AND BLANK SPACE CAN BOTH BE $ $ DELIMITERS. SEQUENTIALLY DISTRIBUTED BLANK SPACES ACT AS ONE $ $ DELIMITER. BLANKS ADJACENT TO A COMMA HAVE NO DELIMITING EFFECT $ $ * A ZERO INPUT CAN BE OMITTED BUT NOT THE DELIMITERS EXCEPT WHEN $ $ THE ZERO INPUTS ARE THE LAST ONES ON A LINE. $ $ * A LINE WHOSE FIRST NON-BLANK SYMBOL IS "$ IS AN INSTRUCTION $ $ LINE WHICH WILL BE IGNORED IN A PROGRAM RUN. $ $ * A LINE WHOSE FIRST NON-BLANK SYMBOL IS NEITHER ONE USED IN THE $ $ ABOVE LIST FOR NUMERICAL INPUT NOR "$, OR WHICH CONTAINS MORE $ $ THAN 3 SYMBOLS OUTSIDE OF THE LIST, IS A COMMENT LINE WHICH WILL $ $ BE SHOWN IN THE OUTPUT FILE. $

Jan 1, 1990

By Thomas E. Marshall, Roy H. Grau

The U.S. Bureau of Mines has developed an acoustic test for determining if a rock salt sample is from a "normal" nongassy salt face or from a gassy face where an outburst has the potential to occur. The test is based on the observation that a salt sample taken near an outburst-prone zone produces an audible popping sound when it is dissolved in water. The sound is produced when pressurized gas that is trapped in salt samples is released. In the acoustic test, the sound is electronically measured, digitized, and transmitted to a microcomputer; the output is an average decibel value that classifies the sample as "normal" or "outburst." The acoustic test procedure and equipment are described, and raw test results and data analysis are shown. Results are also shown for several salt samples that were analyzed using a laser Raman microprobe.

Jan 1, 1990

By M. M. Jones

A procedure for the spectrophotometric determination of uranium has been developed in support of minerals research being conducted by the Bureau of Mines. Uranium is separated from the sample by tributylphosphate extraction from acid solution containing added aluminum nitrate and (ethylene dinitrilo)-tetraacetic acid solutions. The colored uranium-dibenzoy1methane complex is developed in the organic phase by adding an ethanol solution of dibenzoylmethane buffered with triethanolamine. Absorbance is measured at 410 nanometers, and the response is linear up to at least 100 micrograms U30S in the aqueous aliquot taken for analysis. Aliquots containing as little as 8 micrograms U30S may be analyzed with relative errors no greater than ±5 percent. For aliquots containing at least 35 micrograms U308, relative standard deviation at the 95-percent confidence level is about ±2.2 percent. Appropriate procedures are given for analyzing a wide variety of samples.

Jan 1, 1980

By F. N. Kissell

The Bureau of Mines used sulfur hexafluoride (SF6) tracer gas to evaluate the effectiveness of gob ventilation and/or sealing practices at three coal mines, each having different problems associated with their mined-out areas. The purpose of these ventilation studies was to better understand whether current techniques employed for ventilation or sealing are successful at minimizing the potential for gob fires and explosions. The work performed at each mine is discussed: One is a long-wall operation that uses ventilation to carry off hazardous gases, and two are room-and-pillar operations, each with far different concerns, that seal off the gobs to isolate them from the main mine ventilation. In all cases employment of the Bureau's SF6 tracer gas technique resulted in answers to questions raised by the mine operators concerning the effectiveness of their gob ventilation or sealing practices in preventing mine fires.

Jan 1, 1986

By C. E. Jordan

The Bureau of Mines conducted laboratory studies on methods to increase the recovery of brine from slime produced by operating potash plants. The slime was comprised of 80 percent brine saturated with KCl and NaCl, and 20 percent solids. A variety of settling techniques, filtration methods, continuous centrifugation, and novel processing techniques were investigated. Vacuum filtration recovered 6S percent of the brine at 47 gallons of brine per square foot per day. Pressure filtration, on the other hand, recovered 74 percent of the brine at 40.9 gallons of brine per square foot per day. Centrifugation in a 6-inch-diameter continuous decanter-type separator resulted in 42 percent recovery of the brine at a treatment rate of 542 gallons of brine per day. Vertical drains proved to be the most promising novel debrining technique investigated. With this method, 45 percent of the brine was recovered in 3 days.

Jan 1, 1977

By M. D. Schlesinger

Experimental data for coal hydrogenation are presented to show that when a vehicle oil produced from coal is present, coal is hydrogenated to the same high conversion whether molybdenum catalyst is impregnated on the coal or intimately mixed with the slurry. Differences in product distribution could be related to the severity of operating conditions. No minimum mixing time was established, but 2 hours was sufficient. Longer periods of mixing, to 14.75 hours, had no effect on the results. The hydrogenation conditions were in the pressure range of 8,500 to 10,000 p,s,i. at 400° to 500° C. Most of the experiments were made in duplicate. The results were obtained with molybdenum concentrations of 0.01, 0.1, and 1 percent. Al the mentioned pressure range and a time at temperature of 15 to 60 minutes, coal conversions higher than 98 percent were obtained.

Jan 1, 1962

By A. J. Farstad, R. F. Kehrman

Characteristics of metal/non metal mines were evaluated to determine the suitability of applying the U.S. Bureau of Mines electromagnetic location system to the problem of locating trapped driers in metal/non metal mines. Statistical distributions of mine depths and overburden conductivities show that the existing USBM EM system is inadequate for most metal/non metal mines. Alternate approaches to trapped miner location in deep mines were identified and subsequent field tests were conducted at six (6) mines to evaluate their feasibility. The approach considered to be the most promising is one which utilizes the existing manpack transmitting system, modified slightly for a dual frequency output, in conjunction with a sophisticated signal processing receiver on the surface. The main advantage of staying with a "through the earth" approach is that the underground equipment can be kept simple, easily maintained, light- weight and inexpensive.

Jan 1, 1979

By R. C. Corey

Anticipating the need for convenient, economical, and safe means for disposing of combustible wastes contaminated with low-level activity, in connection with private and institutional uses of radioisotopes, the Atomic Energy Commission (AEC) has provided the Bureau of Mines with funds to develop an incinerator for this purpose. A prototype incinerator, designated hereafter as BOMAEC-30, was designed, constructed, and tested, based on fundamental and applied research investigations of the combustion characteristics of rubbish and sawdust, which will comprise the bulk of contaminated wastes. No radioisotopes were used in the tests; the objective was to remove as much particulate matter from the products of combustion as possible. The prototype unit was designed to burn 30 pounds per hour, using 100 percent over fire air admitted tangentially in an all-metal, cylindrical combustion chamber. The gas-cleaning system consisted of special fabric bags and absolute filters.

Jan 1, 1962

By John E. Miller

Supercompressibility factors, Fpv, were derived from experimental compressibility data for five helium-nitrogen mixtures containing from 50 to 100 pct helium. These Fpv values are required as volumetric correction factors for or if ice meter measurement of "crude helium" (helium-nitrogen) purchased by the Government in a program of helium conservation. Although compressibility measurements were made by the Burnett method (2)3 - for pressures from 100 to 3,400 psia and temperatures from 40° to 100° F, Fpv values were needed only for pressures from 400 to 2,000 psia. Consequently, values at increments of 2° F, 2 pct helium, and 10 psia were tabulated only for the required pressure range. Values for pressures outside this range can be calculated from information shown in the tables. Values for the second, third, and fourth coefficients in the equation Z = 1 + BP + CP2 + DP3 are also included.

Jan 1, 1963

This report summarizes the work performed by the Bureau of Mines on the development of analytical procedures for determining metallic and interstitial impurities in high-purity tungsten. Fourteen published methods and seven unpublished methods are briefly described. Carbon, hydrogen, nitrogen, and oxygen, in microgram to higher quantity levels, can be determined by several methods. Trace levels of 29 metallic impurity elements can be determined by optical spectrography, X-ray spectrography, and other instrumental methods.

Jan 1, 1968

By James E. Norman

[The flotation of mica is mentioned frequently in the literature, but must of the references have dealt with the recovery of mica by the old anionic collectors. The first use of the new cationic reagents indicated their superiority- as collectors in the flotation and a. agglomerate tabling of micas, feldspars, quartz, clay, and other acidic mineral, but the separation n of these minerals from each other necessitated study of the flotation of each mineral.]

Jan 1, 1941

By James E. Norman

[The flotation of mica is mentioned frequently in the literature, but most of the references have dealt with the recovery of mica by the old anionic collectors. The first use of the new cationic reagents indicated their superiority as collectors in the flotation and agglomerate tabling of micas, feldspars, guartz, clay, and other acidic minerals, but the separation of these minerals from each other necessitated of the study of the flotation of each mineral.]

Jan 1, 1941

By James R. FitzSimmons

This report describes an instrument developed by the Bureau of Mines as an improved device for examining roof rock in bolt holes. The unit consists of a commercially available fiberoptic unit adapted for use as a flexible stratascope. Field testing in both metal and coal mines has shown the instrument can be easily transported and used by a single operator. The size and flexibility of the instrument eliminate the need for specially drilled holes.

Jan 1, 1979

By A. J. Forney

A high-Btu gas was made at the Bruceton, Pa., laboratories of the Bureau of Mines to demonstrate the feasibility of using the gas as a nonpolluting fuel for automobiles. The pilot plants at Bruceton were revised to combine the processes of coal gasification, gas purification, and catalytic methanation in one overall system. Tests in the Bureau's test automobiles at Bartlesville, Okla., showed the Synthane gas was less polluting than natural gas.

Jan 1, 1972

In 2006, a total of 741 nonmetal mining operations reported employment to the Mine Safety and Health Administration (MSHA).1 These mines (e.g., potash, gypsum, salt) comprised 5.0% of all operations. ? Mines producing common clay comprised 25.2% (n=187) of all nonmetal mining operations. ? Nonmetal mining operations were located in all states and territories except Alaska, Delaware, Hawaii, Maine, New Hampshire, Rhode Island, Puerto Rico, and the Virgin Islands.

Jan 1, 2008

1. In 2002, a total of 2,065 coal mining operations reported employment to the Mine Safety and Health Administration (MSHA). Coal mines comprised 14.2% of all mining operations. • Bituminous mines comprised 92.5% (n = 1,910) and anthracite mines 7.5% (n = 155) of coal mining operations. • More than 70% of all coal mines were located in three states: Kentucky (28.7%), West Virginia (21.7%), and Pennsylvania (20.1%).

Jan 1, 2004

By Edmund S. Leaver

This information circular is written is response to the marry requests for information on the recovery, or reason for poor recovery, of fine gold by the amalgamation process. Checking Gold Content Experience has shown that in many cases error has been made because the true told content of a particular sample or deposit was not known. Fire assays of representative samples give accurate results and should be considered final in determining the gold content.

Jan 1, 1928

By d&apos, Kathleen J. Amico

THIS SUMMARY is shown in volumes I and III of this series on mineral production in the United States (including Alaska and Hawaii), its island possessions, the Canal Zone, and the Commonwealth of Puerto Rico, and on the principal minerals imported into and exported from the United States. For further details on production, see the several commodity and area chapters. A summary table comparing world and U.S. mineral production also is included. [ ]

Jan 1, 1960

By d&apos, Kathleen J. Amico

THIS SUMMARY is shown in volumes I and III of this series on mineral production in the United States (including Alaska and Hawaii), its island possessions, the Canal Zone, and the Commonwealth of Puerto Rico, and on the principal minerals imported into and exported from the United States. For further details on production, see the several commodity and area chapters. A summary table comparing world and U.S. mineral production also is included. [ ]

Jan 1, 1960