Search Documents

By Warren Hastings

This paper describes the methods and costs, in units of labor end materials, of sinking a 7 compartment vertical shaft 1,261 feet through a fractured, water-saturated formation. The shaft, designed for hoisting 2,500 tons a day, is at Friedensville, Lehigh County, Pa., approximately 6 miles south of Allentown and Bethlehem. It was sunk by the E. J. Longyear Co. under contract to the New Jersey Zinc Co. Preparation for shaft sinking W8A begun July 1, 1947, and sinking was completed August 18, 1952. A total of 604,858 man hours was required to sink the shaft.

Jan 1, 1954

By E. D. Gardner

This is one of a series of papers written for the consideration of operators of small gold and silver mines in the West. The paper discusses smelting schedules, general smelting practices that have a bearing on rates, and the reasons for penalties or credits for certain constituents of ores. Crude gold and silver ores generally are shipped to smelters only when milling facilities are not available; however, high tailing losses in milling a high-grade or refractory ore or low smelting rates because of the fluxing value of an are may make direct smelting more economical.

Jan 1, 1936

By H. L. Gilbert

Improvements in production of high-purity chromium metal by magnesium reduction of anhydrous chlorides and by hydrogen treatment of electrolytic chromium are reported. Hydrogen-treated chromium has been arc-melted, and the arc-melted material has been successfully forged, rolled, and swaged. The material also has been forged at liquid-air temperatures. X-ray and metallographic studies indicate the recrystallization temperature of rolled chromium sheet to be about 750° C. Preliminary investigation of hot-bending characteristics of rolled chromium sheet shows the minimum bending temperature to be about 325° C. The heat resistance of chromium has been investigated.

Jan 1, 1952

By Francis X. Cannaday

The Bureau of Mines developed equipment to measure the sonic velocity of pulses transmitted through rock samples varying in size from laboratory specimens to mine pillars in place. Pulses are produced by electronically excited piezoelectric ceramic transducers. Special equipment components were developed by Bureau facilities; other components are commercially available. The technique permits a nondestructive, repetitive, stable, shaped pulse to be used in place of explosive caps or hammer blows. Longitudinal wave travel time measurements were taken on an oscilloscope screen; transverse wave measurements were taken under special field conditions. Results were consistently repeatable within the accuracy of the oscilloscopes utilized.

Jan 1, 1966

By James F. Devine

The radial, vertical, and transverse components of particle velocity were recorded by Bureau of Mines investigators along gage arrays extending in one or two directions for 145 to 3,170 feet at five quarries. Of the 39 quarry blasts, 12 were instantaneous blasts, 5 were of the one hole per delay type, using millisecond delayed caps, and 22 were multiple hole per delay type employing millisecond delay detonating fuse connectors. Charge weight per hole ranged from 8 to 1,500 pounds, and the charge weight per delay interval, including the instantaneous blasts, ranged from 25 to 4,620 pounds.

Jan 1, 1966

The objective of this handbook is to provide the inspector with guidance for recognizing hazards from inhalation contaminants in above ground work areas of underground and surface metal and nonmetal mining and processing facilities and evaluating these hazards by collecting samples or making field determinations and interpreting the analytical results. Portions of the handbook that should prove most useful to the inspectors include a survey check list, rules for determining if sampling is required, list of most frequently encountered contaminants, list of candidate contaminants and their sampling conditions, interpretation of results, and a procedure for a health and safety inspection.

Jan 1, 2011

By V. R. Miller

The Bureau of Mines investigated methods for testing the tensile and sheer strength of cast specimens of bulk solder and of soldered joints in order to increase the strength and extend the useful temperature range of soft solders. A spread-area test for determining the wettability of solder on copper surfaces was developed. Mannitol was used as a flux in spread tests to control spreading and to avoid plating, etching, and other side effects of regular fluxes. Data on commercial and high-purity solders obtained by these methods show more consistency than those reported by others from similar tests.

Jan 1, 1967

By A. D. German

This paper presents one of a series of digests of foreign mining legis- lation and court decisions which is being prepared in advance of a general report relative to the right of American citizens to explore for minerals and to own and operate mines in various foreign countries. This interpretation of tie laws of Ecuador has been prepared from the best available information in Washington, but is released subject to correction and amplification, if necessary, by the proper American diplomatic and consular officers to whom it is being referred through the courtesy of the Department of State..

May 1, 1930

By J. E. Doo1ey

To process and use the heavy ends of petroleum effectively, the development of suitable separation and characterization procedures not currently available was required. A systematic procedure was developed by the Bureau of Mines using such techniques as isothermal and molecular distillation, chemical treatment, silica-alumina gel chromatography, gel permeation chromatography, and spectrometry. Using these techniques, the Bureau achieved a detailed separation and characterization of a 370° to 535° C distillate from Gach Saran, Iran, crude oil. Such a systematic procedure and the semiquantitative data resulting therefrom should be of value in selecting feedstocks and in optimizing petroleum processing operations.

Jan 1, 1973

By William E. Bruce

The Bureau of Mines performed drill calibration tests on two industrial percussive drills of 2-5/8- and 3-1/2-inch piston diameters to determine operating characteristics for their use in conjunction with penetration rate data in developing drillability equations and furthering the knowledge of percussive drills. The use of a linear velocity transducer for measuring piston velocities and application of its instrumentation are described. Data presented include relationships between maximum piston velocity and feed air pressure other results confirm the theory or data of previous investigators, and some comparisons are made with the performance prediction formulas of other investigators.

Jan 1, 1969

By Richard W. Lewis, Lloyd Carpenter

The objective of the investigation was to determine spectrochemically 19 elements in the general range of 0.5 to 1,000 ppm in high - purity hafnium and its compounds . Samples were converted thermally to hafnium dioxide , mixed with buffer - carrier - internal standards , and excited by a dc arc . Spectra were recorded on photographic plates . Transmittance values were recorded densitometrically and converted to relative - intensity ratios . Four groups of standards were used to establish analytical curves from which the concentrations of impurities were obtained . Average precision of the method was 14.2 percent relative standard deviation , and relative error was 4.2 percent .

Jan 1, 1964

By Gordon E. Fletcher

This Bureau of Mines report outlines the atomic absorption analysis of oilfield brines for barium, calcium, copper, iron, lead lithium, magnesium, manganese, potassium, sodium, strontium, and zinc, using the method of additions. The advantages of using atomic absorption are discussed. The method of additions was chosen to overcome large matrix interferences usually found in brines; techniques of overcoming chemical, ionization, and background interferences are also described. The method was used to analyze several hundred oilfield brines and found to be rapid and reasonably accurate. A solvent extraction method was used to concentrate lead, copper, zinc, and iron in low-level samples.

Jan 1, 1974

By J. E. Miller

Primary standard gas mixtures were developed for more accurate calibration of analytical instruments at the Bureau of Mines Helium Research Center and for calibration of analytical instruments used in the helium conservation program. A 10-kg-capacity balance is used to weigh a 4-kg metal cylinder filled to high pressure (1,800 psi maximum) with the component gases of the desired mixture. At 1,800 psi, a cylinder contains about 60 g of helium, or 420 g of nitrogen. An accuracy of ±0.05 mole-percent or better is claimed for each component in the mixtures.

Jan 1, 1965

By R. V. Higgins

This paper describes a method and a computer program for calculating shape factors and areas of channels that turn more than 90° and conduct fluids into the backs of wells. The program represents an improvement over a previous Bureau of Mines investigation by using a 4-point Lagrange interpolation equation instead of a 3-point and by summing areas of trapezoids with either x altitudes or y altitudes. Some of the techniques reported in this paper can also be used to compute the areas between contours and the lengths of lines that turn more than 90°.

Jan 1, 1968

By L. B. Pankratzt

The heat capacity of dimo1ybdenum carbide (Mo2C) was measured from 51° to 298° K, and the entropy at 298.15° K was evaluated. Heat content measurements above 298.15° It were conducted for dimolybdenum carbide (M0caY) and monotantalum carbide (TaC). The results were combined with known heats of formation and the 298.15° K entropy for TaC to obtain values of the heat and free energy of formation from 298.15° K to 1,400° K for MoaC and from 298.15°K to 1,800° K for TaC.

Jan 1, 1966

By Bernard Porter

The densities of LiF, NaF, and KF, of binary mixtures of these alkali fluorides, and of binary mixtures of UF4, ThF4, YF3, LaF3, and CeF with each of tie alkali fluorides were measured as functions of the melt composition and temperature. Molar volumes at 1,000° C were calculated for all the mixtures. Binary systems containing LiF exhibited molar volume ideality. Binary fluoride systems containing either NaF or KF as the alkali fluoride exhibit positive deviations from molar volume additivity. However, molar volumes in the NaF-KF system are ideal.

Jan 1, 1966

By Nabil A. Bibawy

An improved method for preparing gravimetric standard gas mixtures of helium-4 in nitrogen has been developed by the U.S. Bureau of Mines. A single-pan 12-kg analytical balance that has a sensitivity of 3 mg is used to prepare the mixture. The balance will accommodate a cylinder having a volume of approximately 4 L that weighs approximately 5 kg. The method has been improved to a precision of ±O.04 pct by performing four successive dilutions, by improved handling of gases in the manifold, and by using an improved analytical method to select high-purity gases.

Jan 1, 1990

By David E. Emerson

An improved method and apparatus for determining the impurities in helium by preconcentration and subsequent analysis by mass spectrometry are described. Preconcentration of the impurities is accomplished by passing a known volume of helium, at slightly above atmospheric pressure, through a metal coil and trap assembly immersed in liquid helium. The concentrated impurities are then analyzed by mass spectrometry. This method can detect impurities in the range of 0.01 to 600 ppm with an accuracy of better than ±0.05 ppm at the 1-ppm level. One operator can analyze 15 samples in an 8-hour day.

Jan 1, 1970

By E. P. Youngman

This paper presents one of a series of digests of foreign mining legis- ation and court decisions that is being prepared in advance of a generel report elative to the rights of American citizens to explore for minerals and to own nd operate mines in various foreign countries. This interpretation of the laws of Demark and her possessions, has been prepared entirely from answers made by Ernest L. Ives, American charge d'effaires, Copenhagen, to a questionnaire ini- isted by the United States Bureau of Mines and transmitted through the courtesy of the Department of State.

Jun 1, 1932

By H. J. Heinen

Excellent gold recovery was demonstrated in a laboratory-scale leaching test on waste material from an open-pit mine in northeastern Nevada. An injection system of leaching was applied in which the sodium cyanide solution was introduced into the interior of the dump at selected points. Dissolution of gold from the waste material, which assayed 0.06 ounce gold per ton, was readily achieved because the gold occurred as submicroscopic particles in a porous host rock. Gold recovery of 80 percent was obtained in 11 days from material crushed to 1 inch in size, and recovery was 90 percent after 21 days.

Jan 1, 1969