Search Documents

By G. R. Fitterer, C. H. Herty

"INTRODUCTION Manufacturers and consumers of steel have come to realize during the past few years that cleanliness is of great importance in steels which must meet rigid specifications for various physical properties. Of equal importance is the consistent production of steel which is uniform in these properties. For maximum utility steels should be uniform not only from heat to heat, but also from ingot to ingot and within each ingot. In the manufacture of killed steels such as the higher carbon forging grades, uniformity as indicated by the usual chemical analysis in easy to obtain, provided that a normal top discard is taken, as is always the case in steels poured with hot—top practice. No such uniformity, however, holds true for the nonmetallic matter, which consists for the most part of the products of deoxidation of the steel.For a large tonnage of steels which go into articles manufactured by deep—drawing processes, killed steel has never been successfully applied because with the present deoxidation practice, low—carbon killed steel is almost invariably extremely dirty. To obtain the desired qualities for deep drawing, the steel is rimmed, — that is to say, deoxidized with manganese and perhaps a small amount of aluminum, — the resultant product being of high purity in the skin of the ingot, but very badly segregated at the center of the ingot, particularly in the upper—central section. This segregation necessitates a very heavy top discard, and one of the major segregates is carbon which renders the steel too hard to draw properly. If clean, low—carbon killed steel could be made successfully, much better ingot yields would be obtained than by the present rimming steel practice. Furthermore, banded structures and outside and inside seams, which are undoubtedly due in a large measure to blowholes in the ingot, are defects which are very difficult to control in rimmed steel. These defects would be minimized by clean killed steel."

Feb 1, 1931

By R. C. Hickman

Manganiferous breccia formations on three properties were prospected by the Bureau of Mines from January to November 1954 in Johnson County, Tenn. The prospecting consisted of diamond drilling, trenching, shaft sinking, and crosscutting. The results of the exploratory work show the manganiferous material to be low-grade, with little vertical extension. The manuscript on this report was completed February 1955. LOCATION The prospects are in Johnson County, Tenn. (fig. 1), within a radius of 12 miles from Mountain City. The nearest railroad terminal is Damascus, Va., 14 miles from Mountain City.

Jan 1, 1956

By W. R. K. Wu

This Bureau of Mines report presents a statistical study of the repeat abilities of coal-plasticity parameters obtained in the tests with the Gieseler plastometer and the Audibert-Arnu and Hoffmann dilatometers. Repeatability is expressed in terms of one or two standard deviations for the differences between duplicates. The statistical method employed here is summarized. Results are tabulated for the temperature and nontemperature parameters of the three tests.

Jan 1, 1970

By Alton B. Cook

A material balance equation was derived for calculating (1) the initial oil volume and (2) the relationship of average reservoir pressure to net gas in storage in reservoirs used for natural gas storage operations. The equation is also applicable to secondary-recovery operations where reservoirs are completely repressured and gas cycled. Using this equation minimized two probable sources of appreciable error in conventional material balance calculations: inaccurate measuring of and accounting for produced gas, and differences between true reservoir pressure and average reservoir pressures as derived from bottom-hole pressure measurements. A new procedure is presented for calculating water encroachment. By solving the conventional material balance equation and the derived equation for gas storage simultaneously, the values for initial oil in place and net water encroachment can both be determined.

Jan 1, 1966

By J. M. Stuve

In this Bureau of Mines investigation, the low-temperature heat capacities of polycrystalline phases corresponding to the sulfide compounds CoSO?89' CoS1?33, and CoS2 were measured by adiabatic calorimetry within the nominal temperature range 5 to 300 K. The derived absolute entropies S298 were 10.36±O.02, 12.96±O.03, and 16.31±O.03 cal?mol-1?K-l, respectively, assuming third-law behavior. In addition, the standard enthalpy of formation 8Hf298 of CoSO?89 was determined by bromine solution calorimetry. The derived value of 8Hf298 was -50.63±2.1 kcal?mol-1, based on the 8Hf298 of Co0. This result is considerably more negative than previously published formation values based on high-temperature gas equilibrium studies.

Jan 1, 1985

By Kenneth L. Cashdollar

This report describes three types of optical dust probes that have been designed, built, and tested by the Bureau of Mines. Each of the probes measures dust cloud concentrations by the attentuation of light. The first is a single-path-length probe, the second is a double-path-length probe, and the third is a single-path-length probe that employs jets of air to keep the windows of the light source and detector free from dust coating. The theory of operation and the calibration procedures for each of the probes are described. The results of the Bureaus laboratory, mine, and field tests of the probes are also reported.

Jan 1, 1981

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 J. G. Walters

Analyses of light oils produced from the fluidized carbonization of coal at 485°, 550°, 600°, and 660° C are presented. Tar vapors from 485 C fluidized carbonization were thermally treated at 600°, 700°, and .800° C, and the analyses of light oils produced by this treatment are also presented. Procedures were developed for analysis of coal carbonization light oil by gas chromatography to permit a more definitive analysis than can be obtained by the conventional distillation procedure. An increase in low-boiling olefins, benzene, and toluene, a decrease in low-boiling paraffins, and little change in the remainder of the aromatics was observed with increased temperature of carbonization.

Jan 1, 1965

By D. R. Tesarik

Displacement and stress changes in cemented backfill and ore pillars at the Buick Mine, near Boss, MO, were monitored by engineers from the U.S. Bureau of Mines and The Doe Run Co., St Louis, MO. A test area in this room-and-pillar mine was backfilled to provide support when remnant ore pillars were mined. Objectives of this research were to evaluate the effect of backfill on mine stability, observe backfill conditions during pillar removal, and calibrate a numeric model to be used to design other areas of the mine. Relative vertical displacements in the backfill were measured with embedment strain gauges and vertical extensometers. Other types of instruments used were earth pressure cells (to identify loading trends in the backfill), borehole extensometers (to measure relative displacement changes in the mine roof and support pillars), and biaxial stressmeters (to measure stress changes in several support pillars and abutments). Two-and three-dimensional numeric codes were used to model the study area. With information from these codes and the installed instruments, two failed pillars were identified and rock mass properties were estimated.

Jan 1, 2010

By J. H. Field

Results of studies by the Federal Bureau of Mines on a pilot-plant scale for removing hydrogen sulfide and carbonyl sulfide from gas mixtures by the hot carbonate system are given in this publication. Gases containing up to 10 pet. hydrogen sulfide and 48 grains carbonyl sulfide per 100 cu.ft. were treated. In most tests carbon dioxide also was present and was removed simultaneously with the sulfur compounds. Because the rate of absorption of hydrogen sulfide is much more rapid than that of carbon dioxide over a wide temperature range, selective removal of hydrogen sulfide occurred in the bottom section of the absorber near the point of gas entry. Hydrogen sulfide was removed to pipeline specifications with carbonate solutions by using split-stream flows in the absorber and regenerator.

Jan 1, 1960

By Philip W. Holland

The U.S. Bureau of Mines has developed an improved method for determining dissolved helium in water in the concentration range of 4.0 x 10-8 to 270 X 10-8 cm3 He (STP)/cm3 H2O. The method is a modification of a previously reported method that was developed for analrzing surface and subsurface waters in geochemical survey work. Water samples are collected in SOD-cm stainless steel cylinders, and the dissolved gases in a sample are extracted into an evacuated cylinder of equal volume. After addition of 30 psig of nitrogen containing less than 2 ppb helium to the extracted gases, the resulting mixture is analyzed for helium using a helium-tuned mass spectrometer. The helium content of the water sample is determined from an empirical calibration that is established by analyzing standard solutions of helium in water. The accuracy of the method is ±7 pct for helium-in-water concentrations above 10 x 10-8 cm3 He (STP)/cm3 H2O.

Jan 1, 1989

By F. S. Kendorski

This report covers the work on developing criteria for determining when a hazard exists when mining stratified mineral deposits beneath bodies of surface water. The nature of water bodies is considered, the disturbance to the strata induced by mining is described, inundation case histories reviewed, reasonable water inflows derived, and methods of mining to prevent or minimize the hazard are presented. Criteria are given whereby effected industries and agencies can recognize a potential hazard and plan a mine accordingly, releasing considerable mineral reserves otherwise considered unminable.

Jan 1, 1979

By Julie N. Walker

This U.S. Bureau of Mines report reviews the first 2 years of the agency's progress in implementing total quality management (TQM), which the agency refers to as Quality Improvement (QI). All employees have been trained in basic TQM concepts, a cadre of facilitators has been selected and trained, and 13 Bureauwide teams are addressing specific issues that were identified by Bureau employees nationwide as problem areas. Also in place are a Quality Council composed of the Bureau's top executives, a Quality Management Board, and eight QI Working Groups to provide a national 01 infrastructure. There are also Quality Steering Groups at each Bureau location nationwide to address local concerns. In addition to the narrative text, the texts of salient memoranda and other documents are included as appendixes.

Jan 1, 1992

By M. M. Tilman

As part of ongoing research to improve mine safety, the Bureau of Mines conducted research on the corrosion of friction rock stabilizer steels in five Missouri lead and iron mine waters. Electrochemical corrosion tests, including evaluation of pitting tendency, were performed on two types of high-strength, low-alloy (HSLA) steels and galvanized steel in four Missouri lead mine waters and one Missouri iron mine water. The tests were conducted at in-mine water temperatures in both air-saturated and deaerated waters. Static, weight-loss corrosion tests were also conducted on HSLA steel specimens in the five Missouri mine waters for 2,900-h duration at average in-mine water temperatures and air-dissolved oxygen contents of 6 to 7 ppm. Corrosion rates determined by the weight-loss tests were roughly comparable with rates determined electrochemically in deaerated waters containing 0.3 to 0.5 ppm dissolved oxygen content. Passivation of specimen (nongalvanized) surfaces in air-saturated waters resulted in very low electrochemically deter- mined corrosion rates. Pitting-tendency was generally higher for both HSLA steels in air-saturated waters than in deaerated waters. Galvanized steel generally exhibited higher tendency to pitting in the deaerated waters than in the aerated mine waters.

Jan 1, 1985

By L. R. Burdick, J. F. Barkley

The inherent heating value or the amount of heat that will be produced when a coal is completely burned is measured in British thermal units (B. t. u.) per pound of coal . This standard heat unit is the quantity of heat required to raise the temperature of 1 pound of water 1 °F . at about 60 °F . The amount of inherent heat is determined by burning a small quantity of the coal in a heat meter or calorimeter , which gives results in British thermal units . The exact manner of making this test is standardized by the American Society for Testing Materials.4/ The value so determined is the total heat developed by complete burning, with all the products of combustion cooled down to the temperature of the calorimeter . The calorimeter is kept at about room temperature . This total heat is sometimes called the " high" or gross heat value , because it includes the latent heat given up by the water vapor in the products of combustion when the vapor condenses to water in the calorimeter . The heat as measured is reported as the heat of combustion at constant volume , since the burning is carried out in a tightly closed calorimeter chamber whose volume does not change . In actual use , coal is usually burned in an open - end chamber at constant pressure , generally somewhere near atmospheric . As the heat of combustion of coal at constant pressure is very slightly higher than the heat of combustion at constant volume , it might be considered that the heat at constant pressure should be used as the standard reference base . For an ordinary eastern coal the heat at constant pressure is about 16 B. t . u. per pound higher than the heat at constant volume . Calorimeter corrections , ordinarily not considered , that could have been subtracted from the heating value before reporting , may amount to about as much . Hence , the value reported is apt to be more nearly the true heating value at constant pressure than at constant volume .

Dec 1, 1941

By McClelland. John J.

This Bureau of Mines report discusses recent applications of water in-fusion technology to control dust in U.S coal mines and presents recommended guidelines for determining coal seam infusibility. The techniques required to use water infusion are presented in detail. A Bureau case study indicated that water infusion reduced dust levels by 68 pct along a longwall plow face, bringing this section into compliance with the Z.0-mg/m3 Federal dust standard. Similar studies conducted by Occidental Research Corp. under a Bureau contract show water infusion at two longwall double-drum shearer operations produced dust reductions ranging from 38 to 50 pct. Water infusion was found to be cost effective, aver-aging 5 cents per ton.

Jan 1, 1987

Greater mining productivity requires a more efficient cutting process. The cutting force available from today?s mining machines has been optimized with respect to machine size and weight. Researchers have shown that when employing water-jet-assisted cutting, bit forces and drum torques can be reduced significantly, which may allow mining machines to become lighter and more efficient. The Bureau of Mines has initiated a program to develop a water- jet-assisted rotary cutting system using the conventional bit assisted by a directed water jet operating at moderate pressures (3,000 to 10,000 psi). This water-jet-assisted cutting system has the potential to improve cutting efficiency without increasing machine horsepower or water usage (beyond what is presently used for dust control) or requiring fundamental changes in mining practice. IR addition to improvements in productivity, other anticipated benefits of water-jet cutting include reduced generation of respirable dust, elimination of frictional ignitions, increased bit life, reduced fines, and fewer machine vibrations. The papers presented at this open industry meeting discuss the development of water-jet-assisted cutting technology and future application of this technology to a variety of mining techniques including roof drilling and longwall mining.

Jan 1, 1985

By Will H. Coghill

The jig men of the Tri-State (Joplin-Miami) zinc district complain about the flakiness of their mill feed. They believe that the flakiness of the composite grains of gangue and mineral are to blame for losses of zinc; that is, that the flaky grains in the jig tailings have higher zinc tenor than the cubical grains. Although the evidence which follows contradicts this belief, no effort is made to give a final and conclusive answer. On the other hand, there is outlined a positive and mechanical method which the operator may use to pursue this and similar investigations. DISCUSSION OF SCREENING METHOD Hand-sorting is obviously not satisfactory for separating cubical grains from flaky grains because the personal influence can not be removed. Screens, however, may be used with success. A set of each of two types of screens is required; namely, the square-hole type and the rectangular (rectang, oblong) type. The square-hole screens must be of the double Tyler scale; that is, the order of the sieves should be after the fourth root of two instead of the customary square root of two; close sizing is important. The size of the rectang screens may be selected by trials so that a part of the material already closely sized on the square-hole screens, will pass the oblong holes. Obviously, the cubical grains will remain on the rectang and the flaky grains will pass through. Hence the mode of operation is to screen first on square-hole screens and then split the products on the oblong-hole screens.

Jan 1, 1928

By Robert Lee Stahl

Comprehensive field tests were made in the Gas Hills, Wyo., to determine whether surface geophysical techniques could be used to detect and delineate faults in marginal uranium deposits. The tests were made on property owned by Federal American Partners, Gas Hills, Wyo., and included seismic refraction, self-potential, induced polarization, magnetometer, electrical resistivity, airborne infrared thermal scanning, and airborne photography. Of the several geophysical techniques tested in the field, horizontal resistivity profiling with electrode spacings in the range of 25 to 50 feet was most diagnostic of faults. The method is quick, cheap, accurate, and one that can be easily used by personnel employed by mining companies to detect and delineate faults.

Jan 1, 1973

By John Paul Gries

During World War II, when the curtailment of imports led to an unprecedented demand for domestically produced mica, beryl, and other pegmatitic minerals, the Bureau of Mines and the Geological Survey entered upon a program designed to expedite the production of these minerals from the Black Hills area of South Dakota. The program involved mapping, sampling and drilling many pegmatite dikes found in the southern portion of the area and beneficiation tests in the field and in the Bureau of Mines laboratories at Rapid. City, S. Dak., Rolla, Mo., Salt Lake City, Utah, and College Park, Md. This paper describes the mode of occurrence and the sampling and beneficiation tests on one dike, the Helen Beryl pegmatite, which was investigated as part of the general pegmatite study in South Dakota. Investigation of the Helen Beryl Pegmatite by the Bureau began in August 1943 and was terminated in April 1944. During this period the Bureau took a series of bulk samples from pits for beneficiation tests, drove an adit through the center of the dike to obtain feed for a bulk-sampling plant operation, and finally drilled a series of long holes to sample the deposit further. Geologists of the Federal Geological Survey mapped the deposit and the faces of all excavations and logged drill holes from sludge samples recovered from long-hole drilling.

Jan 1, 1949