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By Gregg A. Scott

Upper Stillwater Dam is to be a roller-compacted concrete gravity structure, founded on nearly horizontally bedded sandstone and argillite rock. An overview of the testing and analyses used to evaluate the adequacy of the foundation relative to deformation, seepage, and stability is presented.

Jan 1, 1984

By C. M. Marquardt

Tramp iron and steel moving on a conveyor belt cause small currents to be generated in a coil situated in a strong magnetic field, which are converted to an alternating current and are amplified. The output voltage from the amplifier fires a thyratron with a relay in its anode circuit, which actuates a howler and simultaneously drops a spot of marker material on the belt.

Jan 6, 1950

By Charles J. Speake, Dennis R. Haley, Thomas E. Finch

As there exists a strong trend to computer assisted mine design, this twofold presentation will emphasize an examination of the parameters wed to create a mine design computer program. The program results are a first-order engineering design and evaluation of methods wed to handle the parting or inner burden found in thick-seam western surface coal mines. The alternative selections are draglines, backhoes, scrapers, front-end loaders, shovels, and bucket wheel excavators used in direct stow or haul-back techniques. The computer program wed in the design selection will be explained and typical input and output information shown.

Jan 1, 1980

By John Birkinbine

The iron industry of the United States, and, in fact, of the world, was established with charcoal as fuel. Long before the value of mineral coal was recognized, the carbonization of wood was carried on in connection with various metallurgical processes, but at the present time we look upon establishments using charcoal as the remnant of a former greatness, and are apt to sympathize with the operators because they have no other fuel to depend upon. In the iron

Jan 1, 1883

By H. I. Ashby

INITIAL development of the south orebody at San Manuel is being carried out from the No. 1 and No. 2 shafts. The haulage and grizzly levels are being driven to develop the upper one third of the massive hydrothermally altered and fractured monzonite orebody. This first haulage level has been placed at the 1475-ft level with a grizzly level 60 ft above. The grizzly level will be connected to all service shafts so that men and supplies can come down to the grizzly level and go to working places without congesting the haulage level. These connections are also a vital part of the ventilation plan. The haulage level is being advanced along the north and south fringes of the orebody and connections are being driven to the three shafts now under construction. The No. 1 and No. 2 shafts will serve the development work with supplies, skip hoisting, and ventilation at each shaft and the two shafts are connected on both the grizzly and haulage level.

Jan 7, 1954

By Darrel W. Hansen

Morrow Point Dam and Power Plant are principal features of the Bureau of Reclamation's Curecanti Unit of the Colorado River Storage Project. They are under construction on the Gunnison River 20 miles east of Montrose, Colo. Johnson-MK is the prime contractor, and represents a joint venture of Al Johnson Construction Co., Minneapolis, Minn., and Morrison-Knudsen Co., Inc., Boise, Idaho. The power plant will be housed in an underground chamber in the left abutment, approximately 250 ft behind the original canyon wall. The chamber is 206 ft long and 57 ft wide. The distance from the foundation to the spring line of the roof arch varies from 51 ft in the service bay to 120 ft in the control bay. The roof arch has a rise of 16 ft. The longitudinal center line of the chamber is orientated east-west with the draft tubes discharging nearly due north. Access to the power plant chamber was possible through the cable tunnel, access tunnel, two draft tube tunnels, two penstock tunnels, exploratory tunnel, which became the ventilation tunnel, or the grouting and drainage tunnel leading to the dam. (See Fig. 1.) The shortest and fastest access was through the cable and access tunnels, and the contractor drove these two tunnels simultaneously. The cable tunnel and cable gallery excavation exposed a transverse section, at the west end of the chamber, that was 15 ft wide and extended from the crown to 5 ft below spring line. It was here that arch excavation began. The first 34 ft of advance along the arch was driven on three headings, and the muck was removed through the cable tunnel. Meanwhile, the access tunnel was completed, and a raise was driven from its crown to intersect the advancing arch excavation near the longitudinal centerline

Jan 1, 1968

By J. Parke Channing

THE production and use of copper in the world, like that of other metals, has been of slow growth. In 1880, production in the United States, was only about 60,000,000 lb. and the world's production 325,000,000 lb. Up to 1913 there was a gradual and regular increase in production; in 1912 the production was 1,250,000,000 lb. for the United States and 2,200,-000,000 lb. for the world. At the outbreak of the war there was a slight falling off, both in the United States and elsewhere, but when it was realized that the war was not to be a short one and that copper was one of the most important things for carrying it on, there was a tremendous increase in production every-where. Roughly speaking, the average production for the years 1916, 1917 and 1918 was very close to two billion pounds in the United States and three billion pounds in the world. WAR DEMANDS STIMULATED PRODUCTION Not only did the production of copper in the United States increase, but the same may be said of .all the base metals, particularly of zinc. Much of the zinc used by the Allies came from Australia, but had been smelted in Belgium and Germany, now closed to them. We were called upon to make good this lost supply and in feverish haste built new zinc smelteries and opened new mines. The armistice found the United States with a large surplus of copper on hand, variously estimated at from 800,000,000 to 1,000,000,000 lb. In addition to this surplus in the United States, there were considerable stocks in the hands of the Allies and also immense quantities of unused brass. To. complicate the situa-tion still further, the reclamation of old brass shell cases and other used material was instituted, still further curtailing the demand for new material. This situation was- not appreciated at the time and it was assumed, that the Central Powers would immediately come into the market ? replenish their exhausted stock of copper. During the war Germany had torn down copper trolley wires and roofs, and melted up bronze bells, doors, statues and other copper-bearing material to reclaim this metal for military purposes. But Germany-was unable or at least unwilling immediately to replace her copper substitutes.

Jan 1, 1923

By D. K. Crampton

THE object of this work was to obtain and correlate information on effect of internal stress in variously drawn tubes on several properties. Also, a simple approximate method of comparing types of stress distribution in such variously drawn tubes was sought. There is also included some work on comparison of single and polycrystalline materials and effect of different types of operation and preferred orientation. PREPARATION OF MATERIAL A series of tubes was drawn to study the effect of the type and degree of final reduction on various physical properties and the approximate distribution of stress intensity across the tube wall. The material used all came from a single heat of 70-30 brass melted in a regular production Ajax-Wyatt induction furnace. The analysis of the metal as cast was: copper, 70.36 per cent; lead, 0.04; iron, 0.02; zinc, balance. The material was cast in "shells" with 4 in. outside diameter and 3/4 in. wall thickness. It was drawn part way down according to the usual standard mill schedule and then by suitable individual schedules to finish by a variety of types and degrees of drawing to the same final cases in every instance; namely, 0.750 in. outside diameter by 0.080 in. wall thickness. The exact final draws, together with the percentage area reductions, diameter reductions and gage reductions are given in Table 1.

Jan 1, 1932

By Robert Anderson

The diffraction of x-rays by cold-worked and heavily polished surfaces of metals gives, no evidence of an amorphous state and typically perfect crystallographic diffraction' patterns are obtained. Severely cold-worked metals, reduced as much as 98 per cent. in area, give true crystallographic diffraction patterns, and polished surfaces of large single crystals of metal give typical crystallographic patterns. The conclusion is drawn, on basis of x-ray evidence, that metals are fragmented on cold work and polishing and not amorphized. THE purpose of this paper is to report evidence, regarding, metal: structures, that is contradictory to the amorphous-metal, hypothesis of Beilby, and particularly evidence that is opposed to the proposition that a vitreous amorphous layer is produced by polishing a piece of metal. According to the theory of Beilby, which has been developed, by Rosenhain and others, polishing a piece of metal greatly affects the condition of the metal at or near the surface polished, making that surface entirely different in character from the metal beneath. A vitreous amorphous surface film is said to be formed. The polishing process, on the basis of Beilby's explanation, is well known-and does not' require discussion here, but it is advisable to seek the precise meaning of,., the term "amorphous." According to Beilby, "amorphous means. Non-crystalline in the most intimate sense of the word'; the molecules are not marshalled in crystalline order and orientation." According to Rosenhain, the amorphous condition is that assumed by a metal when, the .crystalline arrangement is completely broken up so that the atoms exist in a state of disorderly arrangement similar to that ;which exists in the liquid state. Thus, from the point of view of the phase rule, the "amorphous phase" is regarded as being identical with the liquid phase. Amorphous metal is often likened to an undercooled liquid. A crystalline substance is one in which the atoms are arranged in space according to some definite repeating geometrical pattern. The existence of amorphous metal has not been definitely proved.

Jan 1, 1925

By A. C. Heath, E. H. Dix

THE importance of aluminum-silicon alloys in the light alloy field is now generally recognized. Where silicon was once considered detrimental to the properties of aluminum, useful alloys now contain as much as 13 per cent. Furthermore, silicon is present as an impurity in aluminum of even the purest grades. Iron is another important impurity in aluminum and like silicon is found in small quantities in the purest aluminum available today. The manner of occurrence of iron and silicon in commercially pure aluminum and many of its alloys exerts a very pronounced influence upon their properties. The effect of large quantities of iron in aluminum-silicon alloys is so detrimental that it has been found necessary to limit the allowable maximum percentage to as low a figure as is consistent with quantity production and satisfactory physical properties. The intimate relation existing between iron and silicon in aluminum and aluminum alloys makes necessary a more complete knowledge of this ternary system. This paper is divided into two principal parts, dealing respectively with aluminum-silicon solubility equilibria and the constitution of aluminum-iron-silicon alloys. PART I.-ALUMINUM-SILICON ALLOYS The early work on this system was largely confined to determining the general form of the diagram and in this respect the results are in good agreement. Briefly, aluminum and silicon form a simple eutectiferous series without compounds. Until recently the solid solubility of silicon in aluminum had not been accurately determined. Fraenkel1 (1908) stated that aluminum will retain 0.5 per cent. silicon in solid solution. Rosenhain, Archbutt and Hanson2 gave the maximum solubility as about 1.50 per cent. and added that "this solubility does not appear

Jan 1, 1928

By Gary E. Melickian

Last year's review was characterized as a year of politics and began an era of legislation. The 1972 review can be similarly characterized, with even more rigid health and safety regulations and environmental legislation. The mining industry should be aware of what's happening in the nuclear power and other fields as a result of the National Environmental Policy Act (NEPA) of 1969, where the environmental impact of most major construction activities are already under close scrutiny. Section 102 of NEPA requires that all federal agencies include a detailed statement on specified environmental conditions as part of every report on proposed actions significantly affecting the quality of the human environment. All such environmental reports must consider the same general conditions: • The environmental impact of the proposed action. • Any adverse environmental effects which cannot be avoided should the proposal be implemented. • Alternatives to the proposed action. • The relationship between local short-term uses of man's environment and the maintenance and enhancement of long-term productivity. • Any irreversible and irretrievable commitments of resources which would be involved in the proposed action should it be implemented.

Jan 2, 1973

By Robert H. Richards

If one holds up a prism, or wedge of glass, with narrow angle, say l° to 2O, and compares the transmitted image with the image seen above or below the prism, the former will be found to be thrown to one side by an amount varying with the angle of the wedge. Speaking of the two rays as the direct ray and the bent ray, we may say, that when the bisecting plane of the prism is at right angles to the line of sight, the angle between the direct ray and the bent ray will be constant for any given prism. If now we place a prism or wedge of glass in such a position that it half-covers the objective of a telescope, we shall obtain on looking through it two images of every object seen—one image by the direct ray, which comes through the unaovered half of the objective, the other which comes through the prism, and is the image by the bent ray. The angle of divergence of these two raps will be constant and unalterable, whether the telescope is directed to a near object, with its eye-piece at increased distance from its objective, or upon a ' distant object, with eye-piece nearer to the objective. That is to say, if the " throw " or apparent dislocation of the image is one foot in one hundred feet it will be two feet in two hundred, ten feet in a thousand, and so on. The usual form of stadia-telescope has at the focal point of the objective two spider-lines, placed at a definite distance apart and intended, let us say, to represent a throw of one foot in one hundred feet. But as the distance between lines remains the same, while the distance from the objective to the webs diflers with every variation in the distance of observed objects, it follows that the angle between the lines of sight which these two spider-lines define cannot be con stant, but must vary with every increase or decrease of distance be tween the instrument and the object viewed. If in Fig. 1 we represent three positions of the spider-lines by W1, W2, W3, and three objects corresponding to those positions by 01, O2, 0, at near, medium and distant positions, we see at

Jan 1, 1892

By F. A. Crossley

The titanium-rich end of the Ti-A1 system has been investigated up to 35 at. pct A1 (23 wt pet). One conzpound Ti3Al was found to occur between primary a and TiAl. It is ordered hcp with DO19 structure, it has virtually no solid-solubility range, and it has a closed maximum at about 875°C. OIL either side of the compound are a +Ti3Al two-phase fields. The limiting a1uminum solubility in primary a at the titanium-rich end is indicated to be 7.5 at. pct A1 (4.4 wt pet) at 550°C and about 6.8 at. pct Al fl wt pct) at 500°C. Quenching alloys from above the a + Ti3Al two-phase field produces the following structures with respect to alloy composition: Up to 13 at. pct A1 (7.8 wt pet), a solid solution; from 15 to 18 at. pct A1 (9 to 11 wt pct), shear transformation product or martensite; from 19 to approximately 30 at. pct (11 to 19 wt pet), submicro-scopic coherent Ti3Al in an a malvix. The twin hcp phase fields reported in the literature are the result of nonequilibrium corzdztions. Ti-A1 alloys, once partitioned by dwelling- in the a + ß phase field during either hot working or heat treatment, are extremely difjicult to homogenize at temperatures below 1000°C. Such partitioned alloys exhibit the characteristics or symptoms of two-phase materials, and may be said to suffer the "twin-phase syndrome". THE earliest investigations of the Ti-A1 system by Ogden et al.1 and Bumps et al.2 reported wide solubility of the primary solid solutions. Aluminum was reported soluble in the low-temperature allomorph to the extent of 37 at. pct (25 wt pct), and the first intermediate phase was reportedly TiA1. Somewhat later Kornilov et al.3 reported a similar diagram with phase boundaries displaced towards lower aluminum contents and higher temperatures. Beginning about this time (1956) reports in the literature made it very clear that one or more intermediate phases occurred at lower aluminum contents than TiAl.4-17 These reports included five major investigations of the titanium-rich end of the Ti-A1 diagram.4,12,14,16,17 Three of these diagrams show two two-phase fields below 37 at. pct Al, while two of them show a single two-phase field. The existence of the phase Ti3A1 is firmly established and is included in each of the diagrams, except one—that of Sato and Huang.12 The new phases are reportedly hcp and differ from primary a only slightly when disordered, and when ordered the "a" parameter is approximately one,4,12,15 two, 6-10,13,14 or four14 times that for primary a. Beyond this, however, the diagrams are remarkable for their lack of agreement. Two tacit assumptions are usually made in phase-diagram determinations of metal systems. These are: 1) equilibrium anneals bring the alloy to equilibrium or to indistinguishable closeness to it, and 2) equilibrium conditions established at elevated temperatures are either "frozen" by rapid quenching for evaluation at room temperature, or quench-transformation products are recognized as such. In the current investigation evidence was obtained that over substantial composition ranges neither of these two conditions was met in any of the more recent major investigations. I) MATERIALS, METHODS, AND TECHNIQUES The alloys of this investigation were prepared by nonc on sum able electrode arc melting. Materials used in the preparation of the alloys are summarized in Table I. The investigative tools employed were: optical and electron microscopy, differential thermal analysis (DTA), disatometry, X-ray diffraction, electron diffraction, and resistometry. Alloys for microscopic and X-ray investigations were prepared as 15-g melts. Alloys containing from 7 through 11 at. pct A1 were hot-rolled out of a furnace at 900°C, from 12 through 15 at. pct out of a furnace at 1000°C, and from 16 through 18 at. pct out of a furnace at 1125°C. Alloys containing more than 18 at. pct A1 could not be hot-rolled. The ingots were covered with Markal coating prior to hot rolling to minimize atmospheric contamination. After hot rolling, alloys containing up to 15 at. pct A1 were ground and pickled to remove 7 mils from each surface; alloys containing 16 and 18 at. pct A1 were skinned to a

Jan 1, 1967

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Jan 1, 1938

By N. J. Olson, G. W. Toop

A regular solution is characterized by a finite molar heat of mixing and entropy due only to ideal or random mixing. The thermodynamic properties of binary regular solutions which exhibit constant atomic coordination number and constant atom-atom intefac-

Jan 1, 1967

By R. S. Bradley, B. K. Miller

The principal producing areas of fire clay in Missouri are: (I) the east central district, which includes Audrain, Callaway, Montgomery, Warren, and Boone Counties (Fig. I); (2) the St. Louis district, which includes St. Louis and St. Louis County; (3) the north central Ozark district, which includes Franklin, Gasconade, Osage, Maries, Phelps, and Crawford Counties. Most of the semiplastic‡ fire clay is found in Audrain, Callaway, Montgomery and St. Louis Counties, and in St. Louis. Flint fire clay is found in Callaway, Audrain, and Montgomery Counties and in most of the north centra! Ozark district. High-alumina diaspore clay is found only in the north central Ozark district, except a few deposits found in Montgomery County. This paper is concerned with the semi-plastic fire clay that occurs in the east central Missouri district near Mexico, Audrain County, Missouri, which is mined by the open-pit method as practiced by the A. P. Green Fire Brick Co. About one-fourth of the semiplastic fire clay in that district is mined in shaft mines, and three-fourths in open pits.

Jan 1, 1942

By B. K. Miller, R. S. Bradley

The principal producing areas of fire clay in Missouri are: (I) the east central district, which includes Audrain, Callaway, Montgomery, Warren, and Boone Counties (Fig. I); (2) the St. Louis district, which includes St. Louis and St. Louis County; (3) the north central Ozark district, which includes Franklin, Gasconade, Osage, Maries, Phelps, and Crawford Counties. Most of the semiplastic‡ fire clay is found in Audrain, Callaway, Montgomery and St. Louis Counties, and in St. Louis. Flint fire clay is found in Callaway, Audrain, and Montgomery Counties and in most of the north centra! Ozark district. High-alumina diaspore clay is found only in the north central Ozark district, except a few deposits found in Montgomery County. This paper is concerned with the semi-plastic fire clay that occurs in the east central Missouri district near Mexico, Audrain County, Missouri, which is mined by the open-pit method as practiced by the A. P. Green Fire Brick Co. About one-fourth of the semiplastic fire clay in that district is mined in shaft mines, and three-fourths in open pits.

Jan 1, 1942

By J. T. Burwell, J. Wulff

As is well known, the alloys of iron containing 18 ± per cent chromium, 8* per cent nickel and less than 1.2 per cent carbon exhibit the same allotropic modifications as iron. The face-centered cubic or gamma phase is stable at high temperatures and the body-centered cubic or alpha ferrite is presumably stable at room temperature. The transformation from the gamma phase to the alpha phase in alloys of the above composition (18-8 or stainless steel) is sluggish; even moderately rapid cooling permits the retention of the gamma phase. Cold-work, however, causes the transformation from gamma to alpha to occur at room temperatures. It is difficult, nevertheless, to induce complete transformation regardless of the method of cold-working. Since metallographic polishing is very effective in transforming the surface austenite to ferrite, as indicated by the magnetic studies of Buehl and Wulff,1 it was decided to investigate the phenomenon by electron diffraction methods. Apparatus The apparatus used (Fig. 1) was a hot-filament type employing movable slits, similar to that described by Germer.2 The sample-to-photographic plate distance was 69 cm. and the accelerating voltage 30 kv. Since electrons do not in general follow geometrical paths, it is necessary that either the electron source or the sample be movable in a plane normal to the beam. In this case the sample is fixed and the electron source is movable. The source is adjusted until the shadow of the sample appears in the brightest part of the beam as viewed on the fluorescent screen, then the slits composing the two pinholes are inoved into position one by one. The system is evacuated by means of a mercury diffusion pump backed up with a Cenco Hypervac oil pump. Pressures lower than 10- mm. of Hg are read on a calibrated ionization gauge.

Jan 1, 1939

By J. T. Burwell, J. Wulff

As is well known, the alloys of iron containing 18 ± per cent chromium, 8* per cent nickel and less than 1.2 per cent carbon exhibit the same allotropic modifications as iron. The face-centered cubic or gamma phase is stable at high temperatures and the body-centered cubic or alpha ferrite is presumably stable at room temperature. The transformation from the gamma phase to the alpha phase in alloys of the above composition (18-8 or stainless steel) is sluggish; even moderately rapid cooling permits the retention of the gamma phase. Cold-work, however, causes the transformation from gamma to alpha to occur at room temperatures. It is difficult, nevertheless, to induce complete transformation regardless of the method of cold-working. Since metallographic polishing is very effective in transforming the surface austenite to ferrite, as indicated by the magnetic studies of Buehl and Wulff,1 it was decided to investigate the phenomenon by electron diffraction methods. Apparatus The apparatus used (Fig. 1) was a hot-filament type employing movable slits, similar to that described by Germer.2 The sample-to-photographic plate distance was 69 cm. and the accelerating voltage 30 kv. Since electrons do not in general follow geometrical paths, it is necessary that either the electron source or the sample be movable in a plane normal to the beam. In this case the sample is fixed and the electron source is movable. The source is adjusted until the shadow of the sample appears in the brightest part of the beam as viewed on the fluorescent screen, then the slits composing the two pinholes are inoved into position one by one. The system is evacuated by means of a mercury diffusion pump backed up with a Cenco Hypervac oil pump. Pressures lower than 10- mm. of Hg are read on a calibrated ionization gauge.

Jan 1, 1939

By Edmond S. Miksch

The morphology and growth rate of ice grown in supercooled water are markedly affected by convection of the water. A dendritic ice sheet with water flowing past the dendrite tip exhibits deflection of the dendrite spine toward the upstream direction, accelerated growth of secondary spines on the upstream side, and suppression 01" secondaries on the downstream side. Flow causes a thin disk to become corrugated, the corrugations being parallel to the flow. Flow causes an increase in the growth rate of the ice. IF a small seed of ice is placed in slightly supercooled water, it grows initially as a disk with the axis of the disk parallel to the c axis of the ice crystal.' It appears that growth in the c direction is inhibited, while growth occurs with equal facility in all directions in the basal plane. It appears that growth rate as a function of interface temperature is very nearly equal for all directions similarly oriented relative to the c axis. Subsequent to the discoid growth, branching occurs and dendrites develop. The primary dendrite spines grow parallel to the six equivalent a axes of the crystal. Secondary, and in some cases, tertiary spines also grow in these directions. The highly anisotropic: dendritic growth indicates that there must be some finite difference of growth rate for different directions in the basal plane. These differences must be quite small, however, since if they were large, the discoid mode would not occur. Hence, it was expected that the dendrite growth direction could be deflected from the crystallographic direction by perturbation of the thermal field at the dendrite tip. Experiments were done in which perturbation of the thermal field was accomplished by causing the supercooled water to flow past the dendrite tip. The flow direction was perpendicular to the c axis of the crystal, and was perpendicular to the primary spine of the unperturbed crystal. Supercooled water was supplied by a 15 cm cubical copper box, which was refrigerated and insulated so it could cool water to temperatures down to —2oC, and maintain the temperature constant to O.l°C for the duration of a run. A lucite channel of rectangular cross-section, 12 by 24 mm, was mounted horizontally in the box, with one end open so water could flow into it, and the other end leading out through the wall of the box to a length of tubing leading: to an orifice plate 123 cm below. cnunMn s MIKSCH, MemberAiMe, formerly Research Associate, Research Associate, Fig. l(b)—Vertical section of apparatus A horizontal cross-section is shown in Fig. l(a), and a vertical section is shown in Fig. l(b). Means for observing the ice are shown in Fig. l(a). Collimated light passes through the ice sheet and forms an image on the ground glass screen. A lucite box containing dry air was employed to prevent condensation. Ice of the desired orientation was provided by the seed holder shown in Fig. l(b). This device was made of lucite, and had a reservoir in which ice could be frozen by placing it in a freezer. This reservoir com-unicated with the outside only through a narrow gap between two sheets of lucite. The seed holder (after ice had been washed off its exterior) was immersed in the tank of supercooled water, the narrow gap terminating in a slot in the top of the flow channel. Ice growing through a thin water layer in the gap between the two sheets of lucite was oriented so its c axis was perpendicular to the sheets. This orientation is an application of a growth phenomenon2 which causes ice growing along a smooth solid surface in supercooled water to orient itself so its c axis is normal to the surface. After the ice grew into the channel, further orientation was necessary, since the direction of the a axis

Jan 1, 1970