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By Alfred Wandke

The problem of vein formation has been of particular interest to the writer for years. As his work for a long time was confined largely to districts showing large deposits of copper ore, it was natural that the efficiency of replacement, as one if not the chief control of the emplacement of the ore, seemed a particularly attractive hypothesis. Of late years, in almost daily underground work in the Guanajuato district, he has collected evidence which makes it certain that in a number of cases the ore solutions were under sufficient pressure to force the rock walls apart and to hold them apart, thus offering an open space for the deposition of vein and ore-bearing material. This paper will concern itself with conditions frequently met with in hypogene ore deposits of the vein type, and will deal in particular with ore occurrence in precious-metal veins of the type classified by Lindgrenl as epithermal deposits, or metalliferous deposits formed near the surface by ascending thermal waters2 and in genetic connection with igneous rocks. To account for the emplacement of this type of ore deposit various writers have suggested the following agencies: 1. Shattering of the wall rocks. 2. Pressure of growing crystals. 3. Magmation, as treated at length by Spurr3. 4. Replacement. 5. Openings produced by folding. 6. Shearing due to gravity. 7. Shrinkage produced by the passage of pre-ore solutions. 8. Contraction joints produced by lateral secretion. To this list there may be added another agency, a discussion of which forms the basis of this paper: 9. Pressure of the ore-bearing solutions.

Jan 1, 1931

By Frank Firmstone

The material described below was made at Furnace No. 2, Longdale, Va., Oct. 28, 1907, during a sudden derangement of working, in the course of which the furnace became entirely bridged over and for some time no solid material whatever descended into the hearth. This caused the hearth to become so completely emptied that, at the tuyere-level, a pricker put in at one tuyere could be seen by looking in at the opposite one. The tap-hole was opened and the iron got out with some difficulty. It ran sluggishly, throwing many sparks, but was not

Jan 1, 1909

By Thomas M. Drown, P. W. Shimer

In a communication to this Institute at the Baltimore meeting, February, 1879,* on the "Determination of Silicon in Pig Iron and Steel," the method recommended was the treatment of the metal with nitric acid until action had ceased, and then evaporating with sulphuric acid until the nitric acid was nearly or quite driven off. After filtration of the siliceous and carbonaceous residue, and washing with hot water and hydrochloric acid, a silica was obtained, on ignition, which was quite pore. Since this paper was read before the Institute, we have had large experience with the method, and

Jan 1, 1880

By F. Kurata, A. F. Bertuzzi, P. C. Davis, T. L. Gore

The phase and volumetric properties of 10 very volatile mixtures are presented for temperatures from — 200°F to above the critical points. These mixtures consisted of natural gases and of mixtures of natural gases with methane and nitrogen. Existing correlations of compressibility factors have been extended to apply to these mixtures. Existing correlations of critical pressures and temperatures do not apply to these mixtures. Methods have been developed for estimating critical temperatures of these mixtures to ± 4°F and critical pressures to 2 5 per cent. These methods apply to other volatile and very volatile mixtures. The results of this work are particularly applicable to the separation of nitrogen from hydrocarbons by low-temperature distillation. INTRODUCTION Knowledge of the low-temperature phase and volumetric properties of natural gases and of other mixtures of the light hydrocarbons is becoming increasingly important as interest in low-temperature separation processes increases. Low-temperature distillation has been used to separate ethane and ethylene from natural gas and from refinery gases for petrochemical uses. Removal of nitrogen from natural gas by low-temperature distillation has been proposed 7,20 as a means of increasing the capacity of existing gas transmission lines and of improving the marketability of the gas. Further application of low-temperature separation processes has been retarded by lack of data on the phase and volumetric behavior of mixtures at low-temperatures and at high pressures. This paper presents the results of determination of the phase and volumetric properties of 10 very volatile mixtures at temperatures from - 200 °F to above the critical point. These mixtures consisted of natural gases with methane and nitrogen. Generalized methods are presented for estimating the critical temperatures, critical pressures, and the densities of such mixtures. EXPERIMENTAL APPARATUS AND PROCEDURES The apparatus and the experimental procedures have been described in an earlier paper13. The method consists of displacing the mixture from a reservoir which is maintained at constant temperature and pressure into an agitated glass equilibrium cell which is maintained at constant temperature. The liquid level within the glass equilibrium cell was visually observed, and the pressure was measured to within & 3 psi with a calibrated Bourdon gage. COMPOSITIONS OF MIXTURES STUDIED The compositions of the mixtures studied are summarized in Table 1. The measured properties included in Table 1 will be discussed later in this paper. The sources of these gases are described below: Gas "A-1'' was obtained from the Phillips Petroleum Co. Its composition was reported in connection with earlier work." The properties of this gas were reported in an earlier paper.13 Gases "A-2, A-3, A-4" were prepared by mixing nitrogen with gas "A-1." Gas "AB-1" was prepared by mixing methane with gas "A-1." The properties of this gas were reported in an earlier paper.'" Gases "AB-2" and "AB-3" were prepared by mixing nitrogen with gas "AB-1." Gas "B" was obtained by W. W. Bodle of J, F. Pritchard & Co. from the primary separator of a well in western Kansas. Gas "C" was obtained from a Cities Service Co. pipeline at Lawrence, Kans. Gas "D" was prepared by mixing gas "AB" with gas "C."

Jan 1, 1955

By O. J. Kensok

THE literature contains three previous studies of the chemical activities of Cd-Mg alloys: Trumbore, Wallace, and craigl obtained chemical activities of magnesium at 543" by performing electromotive-force measurements; Borg and irchenall calculated activities at 590°K based on vapor-pressure measurements of cadmium over Mg-Cd alloys by the Knud-sen effusion method; and Terpilouski and arcka measured the chemical activities of magnesium in the liquid state by means of electromotive-force measurements. In this study the vapor pressure of cadmium was determined over nine solid Cd-Mg alloys in the temperature range 571" to 697°K by the Knudsen effusion method. This study was prompted by the lack of precision in the data reported by Borg and Birchenall. Knudsen cells used during this study were fabricated from 0.020-in.-thick tantalum tubing. The tops and bottoms of the cells were cut from 0.010-in.-thick tantalum sheet, press-fitted, and welded in place. The orifice was drilled in the cell top and subsequently reamed to a knife-edge thickness. The diameter of the orifice was measured with a traveling microscope capable of reading 0.0001 cm. The sample was heated by means of a resistance

Jan 1, 1967

By W. L. Dennen, W. W. Wirth

Research looking toward the reduction of the cost of roof support by substitution of longer-life materials for wooden timber is fully justified by the fact that roof support is an important element of all production costs. Permanent or semipermanent roof support will reduce the expense of timber-maintenance crews during steady operations, but even more markedly during idle periods. The management, therefore, is faced with the important problem of timber renewals, which in times of regular operation are frequently obscured by more urgent problems of production. Increased use of timber in the Anthracite Region of Pennsylvania is caused mainly by increased percentage of coal obtained from robbing areas, which requires more timber for safety than development work, and maintenance of long haulageways through crushed ground despite the fact that less coal is transported over them. The timber reserve in the immediate vicinity of the mines has been depleted to such an extent that it is necessary to secure 70 per cent of the timber requirements from distant sources. Originally, mine timbering in this region was done by largely utilizing round props or legs with round collars. The whole cross section of the tree from which timber was cut was utilized by forming the joints between the legs and the collars with saw and adze, using plank or round saplings for lagging behind the legs and over the collars to prevent material falling between them. The Mine Inspectors' report of 1898 records an important digression from the use of round timber, when two tunnels at the Babylon colliery, near Pittston, Pa., were timbered with 12 by 12-in. square timber sets with mud sills, through quicksand for distances of 425 and 160 ft., respectively. The timbers were lagged with 3-in. plank to control sand. An early step toward the permanent type of roof support was the installation of "brick pillars or perfect arched brick rooms" instead of

Jan 1, 1940

By W. L. Dennen, W. W. Wirth

Research looking toward the reduction of the cost of roof support by substitution of longer-life materials for wooden timber is fully justified by the fact that roof support is an important element of all production costs. Permanent or semipermanent roof support will reduce the expense of timber-maintenance crews during steady operations, but even more markedly during idle periods. The management, therefore, is faced with the important problem of timber renewals, which in times of regular operation are frequently obscured by more urgent problems of production. Increased use of timber in the Anthracite Region of Pennsylvania is caused mainly by increased percentage of coal obtained from robbing areas, which requires more timber for safety than development work, and maintenance of long haulageways through crushed ground despite the fact that less coal is transported over them. The timber reserve in the immediate vicinity of the mines has been depleted to such an extent that it is necessary to secure 70 per cent of the timber requirements from distant sources. Originally, mine timbering in this region was done by largely utilizing round props or legs with round collars. The whole cross section of the tree from which timber was cut was utilized by forming the joints between the legs and the collars with saw and adze, using plank or round saplings for lagging behind the legs and over the collars to prevent material falling between them. The Mine Inspectors' report of 1898 records an important digression from the use of round timber, when two tunnels at the Babylon colliery, near Pittston, Pa., were timbered with 12 by 12-in. square timber sets with mud sills, through quicksand for distances of 425 and 160 ft., respectively. The timbers were lagged with 3-in. plank to control sand. An early step toward the permanent type of roof support was the installation of "brick pillars or perfect arched brick rooms" instead of

Jan 1, 1940

By E. M. Cox, A. S. Skapski, N. H. Nachtrieb, M. C. Bachelder

As a result of using copper-containing scrap in the steelmaking process, the copper content of steels has been steadily increasing for years. Consequently the possible role copper may play in the steelmaking process and in the finished product begins to attract the metallurgists' attention. Some time ago one of the present authors forwarded the idea—based on the results of the analysis of nonmetallic inclusions extracted electrolytically from steels—that sulphur in plain carbon steels is distributed mainly between copper and manganese, the amount of iron sulphide being very small; and that, consequently, the problem of copper and that of sulphur in steel cannot be treated separately.' At the time of the publication of the quoted paper little was known about the relative affinities of copper and manganese for sulphur at high temperatures except that at moderate temperatures (below 1000°C) the affinity of manganese for sulphur is much greater. To gather more experimental data on this subject, the present authors undertook the investigation of the equilibrium constants of the reactions: 2Mn(8 or 1) + S2(g) = 2MnS(s) 4Cu(s or 1) + S2(g) = 2Cu2S (S or I)* 2Fe(s) + S2(g) = 2FeS (s or 1) over a range of temperatures wide enough to establish the dependence of these equilibrium constants on temperature. From the equilibrium constants (K = l/Ps2) the free energy of formation (affinity) can be calculated from F° = -RTln 1/PSt (1) where the standard conditions chosen are: 1 atm of sulphur pressure and the activities of condensed components equal one. The decomposition pressure, Ps2, of sulphur over the respective sulphides is too small to be measured directly, but there is a way of eliminating this difficulty by measuring the equilibrium constant of the reaction between the sulphide and hydrogen. From the latter and from the equilibrium constant of the thermal dissociation of H2S we then calculate Ps2 for the respective sulphide. 2Mn + 2H2S = 2MnS + 2H, 2H2 + S2 = 2H2S_________ 2Mn + S2 = 2MnS The numerical values of the equilibrium constant of the thermal dissociation of H2S at different temperatures were taken from Kelley's paper, "The Thermodynamic Properties of Sulfur and its Inorganic Compounds."² In previous experimental work published by Jellinek and Zakowski3 and by Britzke and Kapustinsky4 the equilibrium constants of the reactions Metal sulphide + H2 = H2S + metal were determined by passing hydrogen, at different rates of flow, over the sulphide, analyzing the resulting H2S + H2 mixture and then extrapolating the H2S/H2 ratio (which is a function of the rate of flow) to the zero speed of flow, a method necessarily involving considerable uncertainty. In the present work the equilibrium ratio was actually measured instead of being extrapolated. The apparatus is shown in Fig 1. Experimental Procedure The sulphides were prepared by the following methods: FeS Powdered iron which had been reduced with hydrogen (ferrum reduc-tum) was mixed in stoichiometric ratio with sublimed sulphur and carefully ground. The mixture was put into an alundum crucible, covered with pure sulphur, and the reaction started by touching the mixture with a glowing iron rod. After the reaction was completed the product (still containing some metallic iron) was again ground with sulphur, put into a Rose crucible, covered with sulphur, and heated in a strong current of pure hydrogen. Analysis of the final product showed 62.46 pct Fe and 36.59 pct S. Theoretical for FeS: 63.53 pct Fe and 36.47 pct S. MnS Manganese sulphide (precipitated and carefully washed with distilled water containing H2S) was dried in a Rose crucible in an atmosphere of H2S and heated in a current of hydrogen for 2 hr at red heat. The product was then ground and ignited for several hours at 1000°C in a current of hydrogen sulphide. Analysis showed 64.53 pct Mn and 36.63 pct S. Theoretical: 63.15 pct Mn and 36.85 pct S. Some MnS samples were prepared from metallic manganese and sublimed sulphur by mixing and grinding them and then heating in a current of hydrogen sulphide in an alundum tube.

Jan 1, 1950

By W. H. Adams

At the present time all the larger and better chemical works of Europe and the United States have introduced, as essential factors in the economical manufacture of sulphuric acid, both Glover towers and Gay-Lussac absorbing columns. The clear exposition of facts given by Bode and Lunge in their very valuable technical contributions since 1870 has slowly but surely brought about radical changes from the old methods of manufacture ; but while the Gay-Lussac column has been known since 1827 and the Glover tower was originated in 1869, yet no theoretical treatise covering the subject fully was given to the world until 1876, when the various contrivances for demonstrating nitrous vitriol were described and criticized by Fr, Bode in a paper "On the Glover Tower" which obtained the great prize of the Berlin Society for the Promotion of Industry.*

Jan 1, 1887

Prof. Mathesius analyzes the running of Howland's furnace No. 19, according to the method described by him in Stahl and Eisen, 1916, Nos. 30 and, 31, and in his work "Die physikalischen und chemischen Grundlagen den Eisenhüttenwesens" (Spamer, Leipzig). By assuming 500 Cal. lost from the hearth by radiation and cooling water per kilogram of pig iron made, a throat-gas temperature of 600° C., and taking the ratio of C02/CO as 0.64, he finds that his diagram would show 0.68 kg. of carbon oxidized per kilogram of pig iron, while Howland gives 0.66 kg. He expresses himself as well satisfied with this test of the accuracy of his theory. Making the further assumption that the heat losses from the shaft are 1,000 Cal. per kilogram of pig iron (twice as

Jan 5, 1917

[Appalachian Petroleum Section: Chairman: Robert H. Edele, 1st V.C.: Robert Vutech, 2nd V.C.: Robert Tullis, Sec.-Treas.: Frederick T. Solomon. Meets last Tuesday of each month in Charleston, W. Va. Balcones Section: Chairman: Dr. Frank W. Jessen, 1st V.C.: Gilbert M. Andreen, 2nd V.C.: Lloyd N. Johnson, Seo.-Treas.: W. C. Vercellino. Big Horn Basin Subsection: Chairman: B. E. Yester, 1st V.C.: Robert J. Woodhall, 2nd V.C.: Herbert A. Koch, Secretary: Dean Costello, Treasurer: Thomas W. DeLong. Meets 2nd Wednesday; alternating between Cody and Worland. Billings Petroleum Section: Chairman: George O. Ellis, 1st V. C.: Robert L. Spottswood, 2nd V. C.: Robert M. Watkins, Sec-Treas.: Joseph H. Bato. Meets 5:30 p.m., 3rd Tuesday at Billings Press Club.]

Jan 1, 1961

By Walter Harvey Weed

Introductory.............449 Summary oF Types............452 I. The Virgilina Type...........452 The Virgilina mines...........452 Location.............452 History.............453 The rocks of the district..........453 The veins.............454 Notes on the mines.... 458 The Holloway. 458; Yancey and Durgy. 465 ; Copper World. 467 ; Frazier. 467 ; Thomas. 467 ; Anaconda. 468; Blue Wing. 468; High Hill. 472; Dorothy.......474 II. The Gold Hill Type...........474 The Gold Hill mine...........475 Location.............475 History............• 475 Surface improvements.......... 476 The rocks............478 Vein.phenomena...........478 Character of the ore..........481 Origin of the ore...........481 Notes on the mine.workings.........482 Other occurrences of ore-deposits of the Gold Hill type.. .. 483 III. The Ducktown Type..........484 The Ducktown mines...........485 Other examples of the Ducktown type....... 494 Alabama mines...........494 North Carolina examples : Ore Knob.......496 Virginia examples..........497 IV. The Catoctin Type.. ......... 498 General characteristics,......... 498 The Linden district...........499 General distribution of the Catoctin type.......503 Introductory. In the early history of this country the existence of copper in the Appalachian region was well known. but no mining mas attempted until the discovery of the Ducktown deposits in

Jan 1, 1901

By A. H. Rhoades, D. T. King, R. J. Gray

Tests and methods of detecting oxidized coal are studied. Particular emphasis is placed on the microscopically discernible changes that accompany the chemical and physical changes affecting the technological properties of coal during oxidation. Coal samples were used from the low-volatile Pocahontas No. 3 Seam, McDowell County, W.V., and from the high-volatile Cedar Grove Seam, Mingo County, W.V. Tests conducted include: carbonization, free-swelling index, phase inversion, froth flotation, Gieseler plasticity, oxygen by difference and by neutron activation, volatile matter, pH of coal slurries, alkali solubility, and electrostatic charge.

Jan 1, 1977

By R. Haynes

ON the basis of compositional changes of a phase observed in a eutectoid Cu-Al alloy1 it has been suggested that mechanisms for the decomposition of the ß phase proposed by earlier workers2-5 were incorrect. These data are reinterpreted in conjunction with lattice parameter data obtained on an alloy containing 12.2 pet Al, whose isothermal transformations have been reported elsewhere.5 The a Lattice Parameters of a 12.2 Pet A1-Cu Alloy—~iffraction patterns of completely transformed specimens were obtained in a back reflection camera using copper Ka radiation. Lattice parameters of

Jan 1, 1959

By W. Randolph Van Lewis

In determilling the relative rate and in fi~lding the point where different inlpurities containecl in copper-matte are eliminated during the process of a converter-blow, the follo~ving results were obtainecl : A converter was selected which was starting on its sccolld charge. The first charge after lining had finished its copper " hot," and conseqaently no copper was adhering to the sides of the lining. All the copper and granulated slag from the previous charpc mcrc dumped, thus removing ally possibility of " salting " the matte to be tested. The coliverter worked fast and well during the entire test. Periods of ten minutes were selected. The converter mas brought from the stack to secure each sanlple of matte to be

Jan 1, 1904

By W. F. James, Richard Murphy, S. N. Kesten, A. H. Lang

The paper is a summary of information on Canadian deposits of uranium and thorium up to the end of 1948, prepared by geologists of Eldorado Mining and Refining Ltd. and by the specialist on uranium deposits for the Geological Survey of Canada. The paper contains a history of Canadian uranium and thorium discoveries, a working classification of the deposits, fairly detailed descriptions of the Eldorado mine and of properties in northern Saskatchewan, and shorter accounts of several other discoveries.

Jan 2, 1950

By Walter J. Johnson

The coals in northern Wyoming and Montana are free-burning and non-caking and range from lignite to bituminous C in rank. Strip and underground mining are employed to supply railroad, utility, industrial, and domestic fuel. The market area includes Iowa, Nebraska, Minnesota, North and South Dakotas, Wyoming, Montana, the Pacific Northwest, and western Canada.

Jan 12, 1953

By M. Hall, Y. P. Chugh, A. Okunola

Effects of moisture absorption on the behavior of the Dykersburg shale overlying Harrisburg coal seam in Southern Illinois are presented in this paper. Cylindrical samples of the shale 2.5 cm in diameter and 5.0 cm long were studied for weight gain and swelling strains at 90, 95, and 100 percent relative humidity and under immersed water conditions. After attaining equilibrium conditions, the samples were studied for changes in the strength and deformation behavior. The depth of moisture penetration was measured using the Vickers microhardness measurements. Using the basic mass transfer concepts, effective diffusion coefficients were computed for the shale.

Jan 1, 1981

By Georg Masing

Jan 1, 1933

By F. F. Schmidt, H. R. Ogden, E. S. Bartlett

ThE solubility of carbon in tantalum has been reported to be very low at temperatures below 1500 C,1'2 increasing to at least 0.02 wt pctl at the eutectic temperature of 2800°C. The solubility limits at low temperatures were based on metallo-

Jan 1, 1963