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By B. Fernow

(Read at the Philadelphia Meeting, February, 1878.) THE question of preserving the forests in this country is an important one, not only to trades using wood but to the whole nation, and though agitated for many years has not received that general consideration which its broad bearing demands. Those who are interested in and working for reform in the treatment of American forests are looking to the government for help, suggesting the creation of a commission to study the conditions of forests at home and abroad, and hope that a sound system of managing the woodlands will be thereby inaugurated. This reform will cost time and money, all the more because the government can bring to bear upon private owners hardly any power but that of good example and encouragement. There is, however, another aspect of the question to which I wish to draw your attention, namely; the more economical use of the valuable material which our forests offer, a more careful and exhaustive utilization of its constituents in all cases where wood or its products are applied. The wasteful consumption of wood in the United States is in every way so enormous as to justify the statement that by merely adopting an economical husbandry in this particular the destruction of forests might be delayed for many years, while the neglect of this imperatively needed and immediately practicable reform deprives legislative remedies of much of their value. In this regard I wish to draw the attention of metallurgists, especially those who are interested in the manufacture of charcoal iron, to a more economical and profitable use of wood in iron manufacture. For thousands of years of human history wood was the main, nay, the only material used for fuel. Mineral coal came into use only in the fourteenth century, and it is only recently that it has largely displaced its less carbonaceous predecessor as fuel. The art of concentrating carbon in the form of charcoal for easier transportation and readier use in distant places was, according to Pliny, known to the ancients long before Christ, and was practiced in all countries, especially in connection with the iron- manufacture.

Jan 1, 1878

By L. J. Murphy

The production of crude oil in the United States is exceeding consumption by one-quarter million barrels per day and, with the possibilities of West Texas, this condition of overproduction, unless controlled, is likely to continue for some time. The resulting low price of oil has caused the operator to observe closely his lease operating costs. The installation of more efficient and reliable machinery has followed and it can well be said that the art of producing oil is on the threshold of a new era. In this advancement electricity has played a leading part. This paper covers only the problem of electricity as applied to lease operation and does not consider other phases of the industry, such as drilling and pipe-line pumping, in which electric power has been utilized economically. In considering electrification of pumping wells, the first question the operator asks is whether or not his costs will be reduced and the second question is whether or not the production will be increased. The third question, although in effect it is closely allied to the first, is the cost of power. The last question can be answered only after a thorough analysis of operating conditions and a study of the power rates prevailing in the particular field under consideration. Within the past few years, the power companies have realized the desirability of a steady 24-hr, pumping load, have made their rates for oil-field service particularly attractive, and in general have shown splendid cooperation in assisting the oil companies in the satisfactory application of electric power to their leases. When everything is taken into consideration, the first cost is practically the same for electric drive as for gas engines when pumping on the beam with individual motors. This cost, at prevailing prices, should aver-age approximately $2200 to $2400 per installation when using 15 to 35-hp., two-speed pumping equipment, including motor and control, countershaft, motor house, belt, installation charges, and a prorated portion of the cost of transmission lines and transformers for serving a number of wells. Since there is practically no difference in the cost of the two installations, it is evident that electricity, to justify its consideration, must have a lower operating cost or produce more oil.

Jan 1, 1928

By E. T. Laker, John C. Loretto

This chapter deals with the process piping aspects of moving slurries in mineral processing plants and the transportation of slurries such as tailings and concentrates over longer distances. The basic data required to select the process piping is given together with an example of line sizing and material selection. Alternative piping materials are discussed together with pumps and pumpbox design and the types of valves and other fittings available to the process piping designer. The long distance transportation of slurries is briefly discussed and a number of references given on this, including papers on actual installations.

Jan 1, 1978

By R. G. Treuting, W. C. Ellis

The twinned state is characterized by a lattice of coincidence sites. Imperfections are required at stable lateral twin interfaces. Twinned regions can occur with relative ease in the diamond cubic IN recent contributions1,2 on the origin and growth of cubic annealing twins, attention has been directed to the orientation relations between such twinned components and their parent matrix. There are some aspects of twinning which may be illuminated by a more detailed consideration of the twinned state" alone. As an extreme example, the dense twinning in cast ingots of germanium,&apos; as contrasted with the rarity of twins in cast face-centered cubic metals, is yet to be accounted for. It has been this that has led us to the present work, which, it will be noted, uses methods and constructions in many respects similar to those of Kronberg and Wilson.&apos; In the cubic systems, a 70" 32&apos; rotation about a <110> axis is angularly equivalent, as to twinning, to the more usually considered 180" rotation about a <111> axis. Figs. 1 and 2 show a (110) projection of a twinned face-centered cubic lattice and a twinned diamond cubic lattice. In both figures, the two adjacent planes A and B, shown by the larger and smaller circles, are sufficient to represent the entire array. In each case a section of lattice, the original atom sites of which are shown by open circles, has been rotated as indicated through 70" 32&apos; to bring an original. [112] direction into coincidence with the [112] diiection. The latter is the intercept on the (110) projection of the (ill) plane normal thereto, the twinning plane. In the face-centered cubic case the rotation can be performed about an axis passing through an atom-site; the mirror plane then is also a composition plane containing atoms common to both twinned and untwinned lattices. The diamond cubic lattice may be construed as two interpenetrated face-centered lattices. Its (111) planes recur in a sequence of alternately short and long interspacings. Consequently a mirror plane for twinning cannot be a composition plane, but must be the bisector of one of the spacings. When the longer spacing is selected, the closest distance of approach across the mirror plane in the [ill] direc- tion is identical with that in the untwinned structure. In each case periodically recurring (ill) planes (parallel with the twinning plane) are found, on which there is coincidence of atom sites of the pre-twinned and twinned orientations; these are indicated by the cross-hatched circles. In the face-centered lattice there is such coincidence every third (ill) plane; in the diamond cubic lattice, on two adjacent planes in every six. At the twinning interface in the latter, there is on each side of the mirror plane a (ill) plane of atoms common to both twin components. Conceivably, there is little influence on a plane of atoms about to be adhered to such a pair of coincidence planes, whether it be laid down in a normal or in a twinned position with respect to the previously formed structure. Slawson% as attributed the high incidence of twinning in diamond to this boundary state. Further examination shows that the motion of intermediate planes can consist of various pairs of equal and opposite translations, for example of (ill) planes in the [l&apos;;i2) direction, the familiar twinning shear, indicated in the small schematics in the figures. Since the translations form a system of shears of alternating sign between coincidence planes, twinning could take place by such a mechanism over an extended region without extensive shear; in fact, in this case any atom moves but the distance in the [1i2] direction. One alternative construction for the face-centered cubic lattice leading to the same end result is illustrated in Fig. 3. The plane (711) with respect to the pretwinning orientation (the twinning plane of Fig. 1) is given, the twinned region arbitrarily bounded by <110> and <112> directions. The coupled shear is identical to that of Fig. 1. The "rotational" movement about coincidence sites generating the same twinned position could consist as shown of the translation a,/d% for each atom of a group of three in the B layer in a different one of the three <112> directions, and a similar translation of the underlying three atoms in the C layer in either the same or the opposite sense. This is not dissimilar to Kronberg and Wilson&apos;s construction for their 22" rotation of three adjacent (111) planes.

Jan 1, 1952

By George I. Adams

Peru is divided into three regions—the coast, the ~ierra, or high mountainous region, and the " montaiia," or forest region of the Amazon basin. The Coast.—The coast is an arid region. No rain falls excepting in the extreme northern part, which borders the Gulf of Guayaquil. There is, however, a slight precipitation in the form of mist (gcirua), which occurs on the coast hills during the so-called winter months. The aridity of the coast is due principally to the antarctic, or Humboldt, ocean-current, which, being cold and having a temperature lower than that of the land, absorbs rather than produces vapors. The coast mists occur during the season when the land is relatively cold. N ear the Gulf of Guayaquil the antarctic current diverges from the coast, so that in the Tumbes valley and adjacent country the conditions in the summer months are such as prodnce rains. In the remaining valleys of the coast, agriculture is made possible only by means of irrigation, and is accordingly very limited in extent, although rich and varied. In the northern and south-central portions of the coast, plains extend inland from the sea, while in the southern part there is a coastal plain separated from the Pacific by a range of coast hills. Between the northern and south-central plains, as well as between the south-central and southern, the foothills of the sierra descend to the seacoast. The Sierra.—The sierra embraces the high land dominated by the lofty cordilleras of the Andes. In the southern part of Peru there are two cordilleras, the western and the eastern, which enter from Chile and Bolivia respectively, and inclose between them the Titicaca Lake basin. To the north of Lake Titicaca these cordilleras unite in the knot of Vilcanota, south of Cuzco. From this knot three cordilleras, known as the western, the central, and the eastern, extend to the northward, reuniting in the

Jan 1, 1909

By Edmund Shaw

IN THE year just past there were produced in the United States about 170,000,000 tons of sand and gravel. Much of this was pit-run material used for gravelling roads and as railroad ballast on lines that did not carry heavy traffic. But more than half of it was marketed as washed and sized, or graded, material. The methods used for preparing sand and gravel for the market have long been used in ore dressing and, as in ore dressing, depend on differences in the specific gravity of two substances or in the size or weight of particles. But many changes in the design and operation of plants and machines have been necessary. In ore dressing, the concentrate is only a small part of the feed; in sand and gravel washing, it is much the larger part of the feed. In addition, such close work as is needed when con¬centrating a metallic ore is not needed when washing gravel; the ability to put through a large tonnage is more important, and sizing, which is only a preliminary process in ore dressing, is an end to be attained. Rock crushers are found in most sand and gravel plants and they are used to break up the larger pieces from the deposit (known as boulders and cobbles) which are removed by a scalping screen. The crusher discharge is usually sent back to the scalping screen, the perforations in this screen setting the maximum size of the finished product.

Jan 2, 1926

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 Leo Dana

As a part of an investigation conducted by the Cement Section of the Bureau of Standards, at the plant of the Security Cement & Lime Co., Security, Md., the High-temperature Measurements Section was called upon to measure temperatures in a dry-process, coal-burning kiln. Although the measurements were made only under the conditions existing in one plant, the methods employed and the conclusions drawn apply, in a general way, to those existing in most plants. As far as we have been able to learn, no sufficiently thorough methods of making accurate pyrometric measurements in the sintering zone and in the rear end of rotary cement kilns have been described. It is believed that in this investigation, data were obtained that can serve as a foundation for further study of the problems of pyrometry in cement kilns. IMPORTANCE OF TEMPERATURE MEASUREMENTS IN ROTARY CEMENT KILNS The manufacture of Portland cement is today fairly well standardized. The various steps in the manufacture have been developed to such an extent that the process is almost automatic. In spite of these strides the efficiency of utilization of heat in the kiln is very low and an undue proportion is wasted; for example, about 50 per cent; ordinarily goes up the stack. In order to prevent these losses, not only should means be provided to utilize the waste heat but instruments, such as pyrometers, should be installed to study and control the operation with the view of minimizing the losses. At the same time, such control will produce a more uniform product. The saving in-fuel that may be effected by the proper use of pyrometers would be much more than their cost. Where these pyrometers should be installed and what they can show are very briefly indicated in the following paragraphs and discussed in greater detail later.

Jan 9, 1919

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 Frank Clemens Smith

The occurrence of the tellurides of gold and silver, even in small quantities, is so rare that their metallurgical treatment has engaged little attention. A residence of several months at one of the few mines in North America the product of which consists entirely of such ore, has led me to arrange a method for its economical treatment. The mine referred to is the Huronian, situated a few miles distant from Jackfish Lake, in Ontario, Canada. The plan proposed is for this peculiar case, and is put on record as possibly suggestive and helpful .in any similar instance, should it occur. Since freight-rates from the mine to the nearest railroad-point were extremely high, and for other economical reasons, the method proposed is modified by the use, as far as possible, of the machinery already at the mine, and is so arranged that bullion instead of concentrates would be obtained as a final product. The ore-vein at the Huronian mine varied in width from about 4 feet at the surface to 2 feet and less at the lowest level—125 feet —and dipped southeast about 88. The rock consisted, on both foot- and hanging-walls, of soft, green Huronian slates carrying much highly crystalline but barren pyrite. The ore carried an inconsiderable amount of galena with iron and copper pyrites, argentite, hessite, sylvanite (or petzite), and probably altaite, the telluride of lead. Near the surface the ore showed considerable native gold, but this disappeared with greater depth. Two complete analyses of minerals containing tellurium are here attached, as they establish the presence of two important compounds: I. Analysis of a mineral supposed at the mine to be sylvanite, but agreeing more closely in composition with petzite (Ag, Au)2 Te: Ag = 41.062 Au =23.691 Te =32.007 Pb = 0.071 SiO2= 0.097 Fe = trace 96.928

Jan 1, 1890

By J. R. Long, T. R. Graham, R. S. Dean

ALTHOUGH considerable information has been published concerning manganese additions to the aluminum bronzes, these data refer principally to the two-phase alloys containing 8 to 11 pct aluminum, with some incidental information on the single-phase alpha solid solution alloys. Strauss1 gives an excellent review of the literature on aluminum bronzes up to 1927 and a bulletin2 of the Copper Development Association brings the bibliography up to 1938. The most extensive work on manganese addition is that of Rosenhain and Lantsberry,3 who investigated alloys ranging up to 10 pct aluminum and up to 10 pct manganese, and presented data on the physical properties of sand-cast, chill-cast, and several wrought alloys. The greater portion of the work, however, concerns alloys ranging from 7 to 10 pct aluminum in the cast condition and sheds little light on the properties of wrought single-phase alloys. Corson4 notes that alloys containing 10 pct manganese and 4 pct aluminum are not hardenable by heat-treatment, while one with 15 pct manganese and 5 pct aluminum can be hardened, but he gives no tensile data on it. In fact, no systematic study of the properties of single-phase wrought alloys containing substantial amounts of manganese has been reported. It should also be noted that most of the investigators worked with alloys containing significant amounts of iron and silicon, and that these impurities, whether intentionally added or accrued from the raw materials used in the preparation of the alloys, may be expected to have a direct bearing on the resultant properties. In the work on alloys made with electrolytic manganese, the Bureau of Mines has undertaken an investigation of the copper-manganese-aluminum system for the purpose of establishing the constitution and properties of high-purity alloys. In a recent paper5 the authors reported a metallographic investigation of the alpha solid solution area and the adjoining fields of the copper-manganese-aluminum system up to 50 pct manganese. This study established the alpha-phase boundaries at 50° temperature levels from 400° to 850°C. It was found that the addition of manganese to copper-aluminum alloys decreases the solubility of aluminum in the alpha phase (Fig I), curving the boundary toward the copper-manganese base line. The greatest change occurs in the first 20 to 25 pct manganese, which decreases the solubility of aluminum to approximately 4 pct. With larger amounts of manganese the alpha boundary tends to parallel the copper-manganese binary. At 1300°F and higher,

Jan 1, 1947

By I. Fatt

Networks of resistors are used as analog computers to obtain relative permeability and resistivity index curves for networks of tubes. These curves have all of the characteristics of those obtained on porous media and, therefore demonstrate the validity of the network of tubes model. INTRODUCTION In paper I&apos; of this series the network model was shown to give information on the structure of porous media that could not be obtained from the bundle of tubes model. The agreement between the capillary pressure characteristics of a network of tubes and those of typical porous media does not prove the validity of the network made. The bundle of tubes model, although it gives less information, also shows this agreement. In this paper the flow properties of a network of tubes are shown to be in agreement with flow properties of porous media. The flow properties of the bundle of tubes model are not in adequate agreement with those of porous media. The dynamic properties of porous media, such as fluid permeability and electrical conductivity, have been found experimentally to be more sensitive functions of structure and pore size distribution than are the static properties such as porosity and capillary pressure characteristics. The network model can, therefore, be best tested by comparing the dynamic properties of a network of tubes with the observed properties of porous media. All static and dynamic properties of a completely valid model must agree with the observed properties. The most commonly measured sensitive dynamic properties are the relative fluid permeability and the relative electrical resistivity. Experimental measurements of these dynamic properties on sandstone, sintered glass, sintered alumina, and soil are reported in the petroleum and soil science literature. These properties were chosen, therefore, for the test of the network model. In the network model, relative permeability is the permeability of the network when some of the tubes are not conducting fluid, relative to the permeability when all tubes are conducting fluid. Similarly, the relative resistivity is the electrical resistivity of the network of tubes when some of the tubes are filled with a nonconductor. relative to the resistivity when all tubes are filled with the electrical conducting fluid. Single Size Tube Network The simplest porous medium is one in which all pores are of the same size. Such media can be approached by packing beds or columns of uniform size particles of sand, glass, or metal. The model of such medium in this study is a network of single size tubes. The network form, the ß factor, is usually not known for real porous media. If the validity of the network model can be established, then the study of the flow properties

Jan 1, 1957

By J. J. Gilman

RECENT experiments have shown that the mar-tensite reaction in a standard tool steel is influenced by the history of the reacting austenite. The martensite reaction proceeds to a given extent at a higher temperature in austenite formed from an annealed spheroidal structure than it does in austenite formed from tempered martensite: that is to say, a prequench lowers the temperature range of the martensite reaction in this steel. Furthermore, a prequench alters the appearance of the martensite as compared to martensite formed from "virgin" austenite. The steel used for this work was a manganese nondeforming tool steel of the following composition: C, 0.85 pct; Mn, 1.43; Si, 0.23; Ni, 0.12; Cr, 0.59; and W, 0.59. A piece from a rolled bar was forged to Vz in. sq and annealed to a spheroidal structure. Disks 1/8 in. thick were used in the experiments. Several sets of the specimens were prepared and austenitized in lead at 1475°F. Three sets were held at 1475°F for 15 min, quenched in water, and immediately reheated to 1475°F. After this quench the three sets were held for 5 min, 30 min, and 3 hr, respectively, at 1475°F and then the individual specimens in each set were quenched in molten baths to 325", 300°, and 275ºF, respectively, and held for 15 sec. Immediately after the quenching treatments? the specimens were tempered at 600°F for 30 sec to darken the martensite and then were quenched in water. The holding times were short enough to avoid isothermal transformation. Three other sets of specimens were given the same final quenching treatments as the first three, but they were austenitized at 1475°F for 20 min, 35 min, and 3 hr and 15 min, respectively, without an intermediate water quench. The two individual specimens from each set were quenched together in order to eliminate quenching errors. Several experiments were run in this way but only the six sets referred to are described in detail because they all yielded essentially the same results. By means of the stated heat treatments the martensite reaction was investigated for: 1—austenite formed from an annealed structure, and 2— austenite formed from tempered martensite. The martensite reactions of the two types of austenite differed significantly. This is shown by Figs. 1 and 2. Comparison of the photographs on the left in Figs. 1 and 2 with those on the right shows that less martensite was formed by a quench to a given temperature from prequenched austenite than from austenite formed from an annealed structure, that is, the prequench suppressed the martensite reaction. The effect was observed for specimens austenitized 20 min, 35 min, and 3 hr and 15 min. A comparison of Figs. 1 and 2 shows that the martensite reactions in both sets of specimens occurred at lower temperatures with increased austenitization time. This was caused by the increased dissolution of residual carbides with time at 1475°F. However, the difference in amount of martensite formed in prequenched austenite as compared to virgin austenite was approximately the same for all three austenitization times. One further observation should be noted. The needles of the martensite formed from virgin austenite are somewhat longer on the average and show less of a tendency to cluster than those of martensite formed from prequenched austenite. This causes the martensite on the right in Figs. 1 and 2 to have a more acicular appearance than the martensite on the left. Since the sets of specimens used in this work were austenitized for identical total lengths of time and the effect of a prequench on the martensite reaction existed for specimens held at the austenitizing tem-

Jan 1, 1953

By W. E. Coxe

In 1857 the Philadelphia and Reading Railroad Company, whose main line extended from Philadelphia to Pottsville, Pennsylvania, with branches into the coal regions of Schuylliill County, made a contract with the Fairmount Rolling Mill, at Philadelphia, for the rerolling of some four thousand tons of iron rails. The essential features of the agreement were that the old rails should be piled with puddled iron and rolled into flats for the rail pile, which latter was • to be of a section seven inches square, and after being heated, and reduced, by rolling, to a bloom of a section about fire inches by six inches, was to be reheated, before being finished into the rail of the T pattern, four inches high, weighing sixty-four pounds per yard. Great care was exercised in the execution of this contract, and the rails being distributed over all parts of the road, gave general satisfaction by their excellent wear. Five years afterward, the principal proprietor and manager of the Fairmount Rolling Mill was elected President of the Reading Railroad, and very many of the rails made under his supervision were still in use in the tracks of the company, of which he had just assumed the management. His first efforts were, therefore, directed to the procuring of more rails of the same quality wherewith to replace those worn out. Here he encountered some trouble, makers refusing to bid because of the details in the specification, the required reheating being the objectionable feature, for which it was generally intimated they would not be sufficiently remunerated for the increased labor, extra coal consumed, and the changes necessary from the established methods of working. Most of the new rails were, therefore, bought, and the old rails rerolled without regard to any particulars as to the manner of piling, heating, etc., each manufacturer furnishing what he deemed the best article possible for the money. As a consequence, rails of all imaginable grades were placed in the tracks, some giving out in six

By W. E. C. Coxe

IN 1857 the Philadelphia and Reading Railroad Company, whose main line extended from Philadelphia to Pottsville, Pennsylvania, with branches into the coal regions of Schuylkill County, made a contract with the Fairmount Rolling Mill, at Philadelphia, for the rerolling of some four thousand tons of iron rails. The essential features of the agreement were that the old rails should be piled with puddled iron and rolled into flats for the rail pile, which latter was to be of a section seven inches square, and after being heated, and reduced, by rolling, to a bloom of a section about five inches by six inches, was to be reheated, before being finished into the rail of the T pattern, four inches high, weighing sixty-four pounds per yard. Great care was exercised in the execution of this contract, and the rails being distributed over all parts of the road, gave general satis¬faction by their excellent wear. Five years afterward, the principal proprietor and manager of the Fairmount Rolling Mill was elected President of the Reading Railroad, and very many of the rails made under his supervision were still in use in the tracks of the company, of which he had just assumed the management. His first efforts were, therefore, directed to the procuring of more rails of the same quality wherewith to replace those worn out. Here he encountered some trouble, makers refusing to bid because of the details in the specification, the required reheating being the objectionable feature, for which it was generally intimated they would not be sufficiently remunerated for the increased labor, extra coal consumed, and the changes necessary from the established methods of working. Most of the new rails were, therefore, bought, and the old rails rerolled without regard to any particulars as to the manner of piling, heating, etc., each manufacturer furnishing what he deemed the best article possible for the money. As a consequence, rails of all imaginable grades were placed in the tracks, some giving out in six

Jan 1, 1877

By J. S. Kasper, R. M. Waterstrat, B. F. Decker

THE existence of v phase in the Mn-Mo system was discovered in this laboratory several years ago,&apos; but neither the conditions of its formation nor its composition were known, and preliminary attempts to reproduce the phase were unsuccessful. We wish now to specify the information appropriate to phase formation on the basis of experiments performed since that time. The starting materials were in every case electrolytic manganese and high purity molybdenum. Two methods of preparation were employed: l—arc-melting varying combinations of the elements in an inert atmosphere and subsequent heat treating, and 2—sintering compressed mixtures of finely divided powders of the elements. In the latter method, the powders were first passed through 200 mesh screen and then compressed into cylinders of % in. diameter and % in. length, which were sintered at elevated temperatures in an atmosphere of dry hydrogen. For some samples, the sintering temperature was 1200°C (for 1 hr), and these were then heat- treated at lower temperatures for times up to 24 hr. Eventually it was found, for the proper composition, that essentially pure a phase could be produced by sintering at 1125°C for 3 hr. Quenching to room temperature was effected by means of a stream of cold, dry hydrogen in a water-cooled chamber. The arc-melting procedure was found to be unsatisfactory after an investigation of many samples at different compositions and temperatures. Large quantities of manganese were vaporized during melting and none of the products were homogeneous or contained extended regions of pure phase. Nonetheless, these experiments established that no formation occurs in the Mn-Mo system below 1115oC, and indicated, at least roughly, the composition range of interest for further exploration. The more definite results obtained from samples produced by the second method are given in Table I. A portion of sample 2 heated for 16 hr at 1000°C in a Vycor tube transformed to molybdenum plus unidentified phases of complex X-ray pattern. From these few results it appears that the region of phase is quite narrow in composition. It is of interest that the composition is such as to make for difficulties in correlating this structure on an electron atom basis with other a structures of iron, cobalt, and nickel. In that respect Mn-Mo shows the same anomaly as Mn-Cr and Mn-V systems.&apos; A second feature is that in common with the two other known molybdenum (Fe-Mo and Co-Mo), Mn-Mo v exists only at elevated temperatures. The X-ray powder pattern of the pure a phase of Mn-Mo is given in Table 11. It agrees well with the patterns established for other structures, especially with that for Fe-Mo as given by Goldschmidt.An attempt is being made to establish whether an ordering of the respective atoms occurs and such information will be reported in a future publication. Acknowledgment The authors acknowledge gratefully the assistance of Mrs. J. R. Belanger in some portions of this work. References &apos;J. S. Kasper, B. F. Decker, and J. R. Belanger: Journal of Applied Physics (1951) 22, p. 361. 2 A. H. Sully: Journal Inst. Metals (1951) 80, p. 173. H. J. Goldschmidt: Research (1949) 2, p. 343.

Jan 1, 1954

By E. A. Devuyst, M. A. Mosoiu, V. A. Ettel

Nickelic hydroxide is an important metallurgical reagent used for precipitating cobalt from nickel sulfate solutions. Existing methods of preparation of nickelic hydroxide involve electrolytic oxidation of Ni(OH)2 or the use of strong oxidizing agents such as chlorine, ozone and persulfate. Although the oxidizing properties of the SO2 + O2 system have been known for some time, e.g., detection of SO2 and oxidation on iron in acidic solution, the application of this system for the preparation of nickelic hydroxide as a process was not considered in the past. The present paper describes a new method for chemical preparation of nickelic hydroxide which has been developed in INCO laboratories. The technique consists of reacting nickelous hydroxide suspensions with a slurry of calcium sulfite in the presence of air or oxygen. The main advantage of the process is the cost of reagents and an absence of soluble by-products (e.g., C1-). The chemistry of this process is unusual since the redox potential obtained during the reaction exceeds that of the oxygen electrode. Therefore, the effect of CaS03 is not just a catalytic acceleration of the reaction NI(OH)~ + 02. The so3= must be involved in the stoichiometry of the overall reaction producing in the initla1 phase some strongly oxidizing intermediate species.

Jan 1, 1981

By W. W. Dudley

Inflow of ground water is an important engineering and safety consideration during construction of large openings underground. The initial step in predicting groundwater inflow involves hydraulic tests in exploratory drill holes. Zones within the area of interest are isolated in the drill hole by inflatable packers and are tested by measuring the water level responses to applied hydraulic stresses. These responses may then be translated into significant hydraulic characteristics of the tested rocks such as transmissivity, hydraulic conductivity, hydraulic potential, and storage coefficient by using a type-curve solution. Once the geometry and necessary hydraulic characteristics have been determined for the rock in the vicinity of the proposed opening, a model can be developed using certain assumptions that will lend itself to treatment with available mathematical methods. The mathematical method applied to the model considers conditions of partial penetration and nonsteady-state, leakyartesian, constant-drawdown discharge of ground water. A type-curve solution results in a curve that gives the variation of discharge (inflow) with time. This technique of predicting ground-water inflow has been used in planning construction of cylindrical chambers for use in underground nuclear experiments by the U.S. Atomic Energy Commission. These chambers have been constructed in low-permeability rocks at depths as much as 6000 ft and under hydraulic heads of thousands of feet.

Jan 1, 1973

By S. T. Wlodek, John Wulff

Dense, adherent, and ductile coatings of chromium can be applied to Molybdenum by selectively freezing out the chromium solute from a supersaturated copper-or tin-rich liquid alloy. The successful exploitation of this technique depends on the control of variables common to any freezing process. Under the most favorable combimtion of supersaturation, nucleation, and mass-transfey, coatings as thick as 0.004 in. can be obtained. In exploratory experiments it was found that a coating of chromium may be applied to molybdenum by immersing the molybdenum body in a supercooled copper-chromium or tin-chromium melt and selectively freezing out the contained chromium onto the molybdenum body. Supercooling of the liquid metal plating bath can be achieved by cooling, or the maintenance of thermal or concentration gradients in the melt. The technique is similar to conventional dip-plating procedures where the sample is immersed in a molten bath of the pure plating medium, except that in these studies, the plating medium consisted of a dilute solution of chromium in liquid tin or copper. The success of this method requires that the base material to be plated be isomorphous with the coating and insoluble in the plating bath. In addition, the plating bath, while having an appreciable solubility for the coating component, must have negligible solid solubility in the solid plate. Such relationships exist in the molybdenum-chromium, chromium-tin, and chromium-copper systems. Liquid tin and copper are satisfactory as the plating solvent, because although chromium is appreciably soluble in both of these liquid metals, solid inter-solubility is almost negligible, and no compound formation occurs. The same relationships exist between molybdenum and copper or tin except that the solubility of molybdenum in liquid tin or copper is insignificant. It is this combination of solubility relationships, as well as the completely isomorphous nature of the molybdenum-chromium system, which allows the formation of a chromium coating on molybdenum by the selective freezing mechanism. Since the main deterrent to the widespread use of molybdenum for high-temperature structural applications is its poor oxidation resistance, the formation of a dense and ductile chromium coating on molybdenum may well be of commercial significance. In addition, the basic principle of coating formation by selective freezing should be applicable to other metallic or even nonmetallic systems. The precipitation of the solute from a liquid metallic solution, for the formation of a protective coating, has not been previously considered in the literature. Frequently, however, a similar phenomenon has been described in the corrosion of metallic heat exchangers by liquid metals1 wherein temperature gradients in the liquid metal heat-transfer medium result in the formation of layers or deposits of metallic residue2 in the cooler portions of the system. Impregnating techniques using liquid baths have been tried as a plating process. Semchyshen and Barr, for instance, have successfully diffused chromium into molybdenum by immersing the molybdenum specimen in a liquid tin-chromium or copper-chromium alloy. This simple holding technique fails to produce a layer of pure chromium and requires prolonged immersion to allow for the diffusion-activated enrichment of the molybdenum. During the course of this investigation, most of the phase relations published for the copper-chromium4 and molybdenum-chromium4 systems, were found reliable. It was necessary, however, to investigate the solubilities of chromium and molybdenum in liquid tin as well as the solubility of molybdenum in liquid copper. These determinations were made by a simpie weight loss technique on materials of the same purity as used in the plating studies. The results of these solubility studies are given in Tables I and I1 and indicate that although the solubility of molybdenum in liquid

Jan 1, 1961

By W. T. Turrall, D. Porter

THE crystal laboratory, Dept. of Physics, Massachusetts Institute of Technology, was confronted with the problem of obtaining a supply of optical grade calcium fluoride (CaF2) for use in growing synthetic CaFe2 crystals. A search of the known fluorspar deposits did not indicate that any quantity of optical spar could be obtained. Even the best material had to be sorted by hand to remove impurities. The process for growing CaF2 crystals developed by Professor D. C. Stockbarger of the Dept. of Physics, M.I.T., necessitates very pure feed materials. Exclusion of impurities is required, even in amounts detectable only spectrographically. The impurities occurred as minute inclusions of SiO2, BaSO4, CaCO3, FeS2, water or air. Crystals up to 4 in. in diam and weighing several pounds are made by the Harshaw Chemical Co. in Cleveland. Since the time required to grow a 4-in. crystal is about one week, and since the cost of manufacture is high, removal of impurities by any concentration method appeared practical. The mineral engineering section of the Dept. of Metallurgy undertook to investigate the possibility of concentrating clear optical fluorspar, -4 mesh +10 mesh, from a feed containing over 99 pct CaF2. Various innovations of the known methods of concentration were considered, but in each case the minute amount of impurities associated with the crystal produced such extremely small differences

Jan 1, 1952