Search Documents

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 H. E. Powell

This study was made to determine the capabilities and limitations of the hydrocyclone for separating quartz sand from impure clays, Optimum operating conditions for beneficiating typical subgrade clays were determined. Estimates are furnished for installation and direct operating costs of hydrocyclones in such separations. Laboratory models of commercial hydrocyclones were used to beneficiate a suite of fire clays including plastic, semiflint, and flint types, all of which were contaminated with quartz in amounts ranging from 3 to more than 62 percent. Results show that this technique is not limited to a single type of clay but is applicable to clays ranging from plastic through flint, Under proper conditions use of this technique will result in good separation of the sand and good recovery of a useful clay mineral concentrate. Rejection of quartz from the clays investigated ranged from a low of 82.4 percent with an alumina recovery of 71.2 percent to a high of 99.0 percent with an alumina recovery of 85.6 percent.

Jan 1, 1963

By S. M. Shelton, W. A. Calhoun, M. M. Fine, T. L. Johnston

"FOREWORDFerrograde manganese ore or its equivalent is essential to the manufacture of every ton of steel produced; although it is well known that there are large deposits of low-grade are in the United States, the production of substantial amounts of ferrograde material from domestic sources presents a problem that becomes more and more critical as the stockpiled ore depleted through inability to procure adequate supplies from foreign sources. Consequently, a program of laboratory,and pilot-plant investigation designed to solve the problem of obtaining a domestic supply of manganese has been undertaken by the Metallurgical Division, Bureau of Mines.This paper is one of a new series that include reports of results obtained in the various investigations conducted under the manganese program. The scope of the program and the organization that was set up to direct and supervise the were discussed in the foreword of the first paper of this series, Report of Investigations 3606 Manganese Investigations. 1. Concentration of Manganese Ores,from the Drum Mountain District, Utah, by S. R. J. D. Vincent, and C. R. Schack. Other reports will be published as the work progresses."

Mar 1, 1942

By J. B. Zadra, S. M. Shelton, M. M. Fine

"Ferrograde manganese ore or its equivalent is essential to the manufacture of every ton of steel produced; although it is well known that there are large deposits of low-grade ore in the United States, the production of substantial amounts of ferrograde material from domestic sources presents a problem that becomes more and more critical as the stockpiled ore is depleted through inability to procure adequate supplies from foreign sources. Consequently, a program of laboratory and pilot-plant investigation designed to solve the problem of obtaining a domestic supply of manganese has been undertaken by the Metallurgical Division, Bureau of Mines.This paper is one of a new series that will include reports of results obtained in the various investigations conducted under the manganese program. The scope of the program and the organization that woo set up to direct and supervise the work were discussed in the foreword of the first paper of this series, Report of Investigations 3606, Manganese Investigations. 1. Concentration of Manganese Ores from the Drum Mountain District, Utah, by S. R. Zimmerley, J. D. Vincent, and C. R. Schack. Other reports will be published as the work progresses."

Mar 1, 1942

By Robert W. Ageton

Optimal planning for mining the deep, lead-zinc-silver deposits of the Coeur d'Alene mining district, Shoshone County, Idaho, could be facilitated by a knowledge of the magnitude and direction of the pressure acting in the virgin rock. The distribution of primary stresses should be considered in order to prevent possibly destructive mining-induced stress concentrations. This particular investigation was concerned with determining stress in a zone 4,000 feet below the surface and known to be ender stress concentrations due to mining operations. Disking of the stress-relief cores obtained in a vertical down hole permitted qualitative evaluation from visual observations; the results indicate that a high lateral stress existed at the time the measurements were made. Stress-ellipsoid determinations gave a compressive principal stress of -13,000 psi oriented about N 45° W and nearly horizontal, a compressive principal stress of -11,000 psi oriented about S 45° W and abut 60° off the vertical pointing away from the vein, and a compressive principal stress -5 -7,000 psi oriented N 45° E and about 60° off the vertical, pointing toward the vein. Subsequent to the overcoring stress-relief drilling, a rock burst occurred about 100 feet northwest of the test site.

Jan 1, 1967

By R. D. Leitch

"INTRODUCTION This report is another of the series on the effect of drouth and low water on the pollution of streams by coalmine drainage. A previous report3 dealt with work on Bennett Branch of Sinnanahoning Creek, Pa. This report deals with the results obtained during a similar study of Black Lick Creek, Two Lick Creek, and Yellow Creek. All of these belong to the same drainage system. Two Lick Creek is a tributary to Black Lick Creek, and in turn Yellow Creek is a tributary to Two Lick Creek, as shown in Figure 1.Black Lick Creek was of such a volume that a seasonal investigation was not entirely feasible. Yellow Creek was found to have mines only near the mouth, except a few of status unknown to the writer at the extreme head-waters, and the stream was also more or less inaccessible for regular and frequent sampling. Two Lick Creek was found to be most suitable of the three.ACKNOWLEDGMENTThe work reported has been carried on under the direction and with the advice of Dr. R. R. Sayers, chief, health and safety branch, and W. P. Yant, supervising engineer, Pittsburgh Experiment Station."

Jul 1, 1931

1. In 2001, a total of 281 metal mining operations reported employment to the Mine Safety and Health Administration (MSHA) (down from 309 metal mines in 2000). Metal mines were the smallest mining sector, 1 comprising 1.9% of all mining operations. This was the lowest percentage of all mining sectors. • The median number of operator employees per metal mine was 17.5.2 • Gold mines comprised 43.1% (n = 121) of all metal mining operations. Other types of metal mines were copper ore (n = 37, 13.2%), iron ore (n = 27, 9.6%), and lead and/or zinc ore (n = 24, 8.5%). • Nearly 20% (n = 55) of metal mines were located in Nevada.

Jul 1, 2003

By Harry R. Nicholls

As part of the pre- and post - shot mine examination at Project GNOME , acceleration data were recorded underground from a series of chemical explosive shots . The cube root of the charge weight was used to scale acceleration and distance because charge weight was not constant . Regression analysis of particle acceleration - distance data gave the following propagation equation : A W1 /3 = 5.10 x 105 ( R / W¹ / 3 ) −2 .43 The quantity A W1 /3 is scaled particle acceleration expressed in g's - lbs¹ / 3 , and R/W1 /3 is scaled distance expressed in ft / lbs¹ /3 Data obtained from the nuclear explosion were scaled and fall within one standard deviation of the calculated propagation law for the smaller shots . Cube root scaling laws were adequate to group acceleration data from explosive charges varying by a factor of more than 1 x 10 in charge weight and over shot - to - gage distances varying from 100 to 46,000 feet . Data obtained from a series of small tests provided sufficient data from which reliable predictions of acceleration could be made for the large nuclear explosion .

Jan 1, 1964

By K. K. Kershner

Sulfide ore concentrates containing cobalt, nickel, copper, lead, and iron were salt roasted and leached on a laboratory scale. More than 95 percent of the cobalt, nickel, and copper was recovered. Heating patterns for salt roasting different concentrates were established. More cobalt, nickel, and copper were recovered from a bulk concentrate composed of a mixture of copper concentrate and iron concentrate. This mixture corresponded roughly with the mixture of these materials in stockpiles in southeastern Missouri. A temperature range of 375° to 400° C. was best for salt roasting. Metal chlorides were leached at a pH of 1 from chloridized charges of concentrates, Although the amounts of cobalt, nickel, and copper extracted were high, the amount of iron dissolved simultaneously interfered with subsequent separation and recovery of these metals. The amount of dissolved iron was reduced substantially by steam treating chloridized charges of bulk concentrate at 300° C. In this way, the ratios of cobalt, nickel, and copper to iron in leach liquors permitted satisfactory separation and recovery of these metals. INTRODUCTION The Federal Bureau of Mines is experimenting with chloridizing reactions.4 5 6 7/ Salt roasting of sulfide ores and concentrates, or their calcines, to form metal chlorides has certain advantages. Chlorides of

Jan 1, 1961

Determine the appropriate spacing and alarm levels for carbon monoxide and smoke sensors used for fire detection in underground coal mine conveyor belt entries. Background Fire represents one of the most severe hazards in underground coal mines. Early-warning fire detection in underground coal mines is essential to successfully implement and execute evacuation and control measures. Both carbon monoxide (CO) and smoke sensors have the ability to provide reliable early-warning capability, provided that they are spaced properly and set at the appropriate alarm levels. The U.S. Bureau of Mines conducted a series of large-scale experiments where a small coal fire was used to ignite a conveyor belt at air velocities of 0.76 to 6.1 m/s. The test configuration was purposely designed to model a worst-case fire scenario for fires that develop within conveyor belt entries in underground coal mines. During the tests, CO and smoke levels were continuously measured to determine alarm times and alarm levels as the fire intensity progressed. The data from these tests indicated that for a given sensor spacing, the time to reach a preset alarm threshold depends upon the belt entry air velocity and cross-sectional area. Analysis of this data resulted in the equations and nomographs for CO and smoke sensor spacing, and alarm levels contained in Bureau of Mines RI 9380, "Fire Detection for Conveyor Belt Entries."

Jan 1, 1993

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 R. R. Brown

The Bureau of Mines undertook a limited feasibility study to determine the practicality of removing copper from automobile scrap by thermal treatment. Test specimens, prepared by wrapping bare and insulated copper wire around small steel coupons, were heated at 600° to 1,150° C in various atmospheres for different lengths of time under both static and dynamic conditions. The tests indicated that adequate removal of copper cannot be effected by thermal treatment of scrap above the melting point of copper. Tests showed that copper present in scrap as insulated wire is embrittled by thermal treatment at 800° to 900° C if the insulation contains lead, and that the embrittled copper is almost completely removed by a mechanical action such as tumbling. Also chemical pretreatment of specimens to effect embrittlement of copper and the magnetic separation of oxide scale were studied. Tests showed that bare copper can be embrittled by depositing waterglass (Na, Si409) on copper prior to thermal treatment.

Jan 1, 1968

By J. E. Matta

The Bureau of Mines made laboratory absorption measurements on oil shale samples, which showed that the amount of methane absorbed is proportional to pressure and oil yield, and can be much larger than would be predicted based solely on porosity. Oil shale cores collected in the field were also measured for their gas content using the Bureau of Mines direct method. Cores taken from deep locations and far from outcrops yielded more gas than cores from shallower locations or at outcrops, when taking into account variations in oil yield, and all data indicate that oil shale mines that are both deep and far from an out-crop will emit low levels of methane gas.

Jan 1, 1977

By F. E. Griffith

Cost data are given for five methods of secondary backfilling of strip mines previously partially backfilled. The operations were conducted in north-central Pennsylvania; an average of 600 linear feet of highwall were backfilled in each trial. Major obstacles and the relative merits of the methods are discussed.

Jan 1, 1966

By Maria I. De Rosa

For all coal mining categories, data on coal mine fires during 1990-1999 have been reported as actual numbers and calculated values. 1. For each mining category, actual numbers include the total number of fires, fire injuries, employees' working hours, lost workdays, and coal production (for underground and surface mines only) for a 1 0-year period (1 990- 1999) and for five successive 2-year periods with the 10-year period. These numbers have also been reported by state ( 10-year period). The actual number of fire fatalities has been reported by time period. Furthermore, actual numbers of fires for the five 2-year periods have been reported by ignition source, method of detection and suppression, equipment involved, location, and burning material. Actual numbers of fire injuries per number of fires causing injuries and total fires have been reported by year, ignition source, equipment involved, and location. 2. For each mining category, the calculated values include the fire and injury risk rates during the 10-year period and the five 2-year periods. The fire risk rate (Frr) values were calculated according to the USBM formula [Pornroy and Carigiet 19951. The injury risk rate (Irr) values were calculated according to the MSHA formula [MSHA 1991a, 1992, 1993, 1994a, 1995a, 1996, 1997, 1998b, 1999c, 20001. Also, risk rate values for individual states (10-year period) were calculated according to the above-mentioned formulas. Of note is that only the risk rate values for the 10-year and five 2-year periods and risk rate values for individual states with the highest number of fires and fue injuries were considered for comparison purposes. The fatality risk rate values were not calculated because of the extremely small number of fire fatalities during the 1 0-year period. 3. Calculations of risk rate values are as follows: a. Fire risk rate (Frr) value: Number of fires per million tons of coal produced [Pornroy and Carigiet 19951. b. Injury risk rate (Irr) value: Number of fire injuries multiplied by 200,000 working hours per total employees' working hours [MSHA 1991a, l992,1993,1994a, 1995a, 1996, 1997, 1998b, 1999c, 20001. The Irr value is the average risk rate value for the number of fire injuries per 200,000 working hours for a given time period.

Jan 1, 2004

By S. P. Holt, Robert S. Sanford

"INTRODUCTION The wartime demand for iron ore and alloy steel on the west coast revived interest in iron reserves in western United States and Alaska. Magnetite was known to have been the most abundant metallic mineral at some of the old copper mines on Prince of Wales Island. In the summer of 1942, the Bureau of Mines began a program of preliminary investigation followed by core-drilling two magnetite deposits on the island.The Poor Man iron deposit on Kasaan Peninsula, Prince of Wales Island, Southeastern Alaska, was examined in August 1942 by Robert L. Thorne, associate mining engineer of the Bureau of Mines, and John C. Reed and B. N. Goddard, geologists of the Federal Geological Survey in September 1942 the area was mapped geologically and a magnetic survey was made by the Geological Survey. In October and November 1942, a more thorough preliminary examination, which included cleaning out and sampling old adits and trenches, was made by thesenior author, Robert L. Thorne, and Aner W. Erickson, engineers of the Bureau. J. G. Shepherd, a consultant of the Bureau, spent two weeks in March and April 1943 investigating the Poor Man and other deposits on Kasaan Peninsula. Core drilling was completed in June 1943.L. A. Warner, of the Geological Survey, examined all cores and interpreted structural data revealed by the drilling."

Oct 1, 1946

By James Paone

The Bureau of Mines made drillability studies with impregnated diamond bits in the laboratory on 7 rock types and in the field on 21 different rock types. Results indicate that drill parameters of rotational speed, thrust, and torque must produce sufficient applied forces to induce stress levels that cause continuous failure in rock to achieve efficient penetration rates. Higher rotational speeds appear to be more effective in drilling relatively harder rocks, although the increased speed causes more bit wear; increases in thrust result in higher drilling rates but not linearly; and up to a critical value a linear relation exists between torque and penetration rate for a specific rock type. Penetration rates with impregnated bits show a trend similar to that obtained with surface-set bits for rock under 25,000 psi compressive strength.

Jan 1, 1966

By M. H. Kersten, G. A. Brady, Jerry W. Ramsey

Anthracite samples were oxidized with nitric acid to prepare products representing intermediate stages of oxidation . Similar oxidizing conditions affected different anthracites to varying degrees as characterized by peptization behavior with 0.1 N NaOH . Techniques used in attempts to separate and characterize the products included esterification , absorption spectrophotometry , sublimation , chromatography , electrophoresis , metal salt formation , and solvent extraction . Mellitic acid , either free or in the form of metallic salts , was identified in the acid- soluble products from 10 tests in which the anthracite was treated with nitric acid for periods varying from 24 to 1,000 hours . pentacarboxylic acid was also found in some products . Other benzene carboxylic acids were not present in amounts detectable by the methods used in this study . The acid- insoluble residue from nitric acid treatment varied significantly in solubility behavior toward different classes of solvents . The most effective ones tried included polar oxygenated solvents and pyridine . Infrared spectra of the extracted material indicated that similar compounds were extracted by the different solvents . Aliphatic amines and aniline peptized the residue and o- toluidine reacted with it . Organic material separated from the residue by peptization with dimethylformamide contained 1 percent ash , consisting of more than 50 percent zirconium .

Jan 1, 1964

As part of its regular program to provide timely information on domestic mineral commodities, the Bureau of Mines conducted an engineering appraisal of more than 1,300 lode and placer gold deposits in the United States to deter-mine their gold production potential. While these deposits were estimated to contain over 400 million ounces of gold, only 9 million ounces, or slightly more than 2 percent, was found to be producible at $35 per ounce under prevailing mining and metallurgical technologies. The study revealed that any significant increase in available gold in the United States is most likely to come from the discovery of new sources, intensive exploration and development of the more promising known mineralized areas, and development of new or improved mining and metallurgical techniques.

Jan 1, 1967

By J. S. Tosh

The Federal Bureau of Mines has investigated the equilibrium of the system potassium carbonate (K2C03) potassium bicarbonate (KHCO3) potassium bisulfide (KHS) carbon dioxide (C02) hydrogen sulfide (H2S) water (H20). Partial pressures of hydrogen sulfide, carbon dioxide, and water vapor were measured at 70° to 130° C. over solutions of 20-, 30-, and 40-percent-equivalent potassium carbonate containing from 20 to 3,000 grains of equivalent hydrogen sulfide per gallon of solution. This study was made to obtain equilibrium data for evaluating the feasibility of using solutions of hot potassium carbonate for removing, hydrogen sulfide from gas mixtures. The equilibrium partial pressure of hydrogen sulfide may be correlated with the ratio of the molal concentrations of the solutes (KHC03) (KHS)/ (K2CO3). The relationship is shown graphically for the 30- and 40-percent solutions. Once this ratio is determined, the partial pressure of hydrogen sulfide can be obtained from the curves. The equilibrium data show that effective removal of both carbon dioxide and hydrogen sulfide can be achieved simultaneously with hot solutions of potassium carbonate.

Jan 1, 1960