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By J. W. Powell

A Federal statute, enacted several years since, provides for the preparation of a geologic map of the United States. There are three requisites for a geologic map. The first is a suitable base- or surface-map upon which the rock-formations may be platted by means of conventions ; the second is a classification of the rocks and formations, and the third is a system of conventions by which the rocks and formations may be represented on the map. When the work of the Federal bureau created to prepare the geologic map was commenced, a topographic survey of the country was undertaken for the purpose of making maps suitable for the use of geologists in the field and for the representation of the geology; and this work has ever since been continued. The surveys have now extended over about one-fifth of the national domain, and are mapped on a series of atlas-sheets, each constituting a section of the great map of the United States. About 700 of these atlas-sheets are completed. They are in extended use among engineers, miners, prospectors, map-publishers and educators, and are thus widely known; moreover, these base-maps have been exhibited, described and discussed at meetings of the Institute, and thus do not require detailed consideration. Classification of Bocks and Formations. Modern classification is designed to express natural relation. In the beginning of observational science, or natural science, objects were discriminated and grouped by differences and resemblances; but at first the differences and resemblances recognized in the classification were external, even superficia1,'and often confined to single features. Later, groups of features and characteristics, both external and internal, were recognized as the basis of classification ; and of recent years, throughout the entire domain of biology, and to a considerable extent in the kindred sciences, classification is based not

Jan 1, 1893

By Stephen Taber

INTRODUCTION THE term asbestos, as commonly used, includes half a dozen minerals all having a well-developed fibrous structure, but differing in chemical composition and in some of their physical, properties. In its strict application the name is limited to the fibrous varieties of the monoclinic amphiboles. Commercially, however, the most important of the asbestiform minerals is chrysotile, a fibrous variety of serpentine. About 95 per cent. of the asbestos used in manufacturing is chrysotile, and it commands a much higher price than any of the other fibrous minerals now on the market. Although the production of asbestos has increased rapidly in recent years, comparatively little has been published concerning its origin. The present paper is preliminary in its nature, and therefore does not pretend to exhaust the subject. The ideas herein developed are the result of field investigation, laboratory experiments in the growth of fibrous

Jan 10, 1916

By John R. Spencer

A capillary tube variable volume cell is described, which has operated satisfactorily over a range of 100°F and 3,500 psi to 550°F and 1,500 psi. The cell contents are entirely visible over the length of the capillary with the exception of a space at the top amounting to three per cent of the total volume. Observations on the critical behavior of simple systems have been greatly facilitated by the apparatus, it being possible to establish the critical conditions for a particular mixture in the course of a day's run. INTRODUCTION Many types of apparatus have been designed for obtaining data on the phase relationships of hydrocarbon systems. Such apparatus can in general be subdivided into two classifications; (l), indirect measurement of phase volume, and (2), direct visual observation of phase volume, each of which has outstanding advantages and disadvantages. Indirect measurement of phase volume requires the use of rather elaborate apparatus including internal probes in which are located the device for determining the locus of the interface between phases. Such equipment is by its very nature costly, and is complex from the standpoint of operating technique. Probing techniques can be used, however, over wide ranges of temperature and pressure with a high degree of reproducibility. Apparatus for visual observation of phase behavior obviously has the advantage of enabling the experimenter to see exactly what takes place, but because the material to be tested is contained in a cell constructed of both metal and glass, is limited severely as to the temperature range of operation. Furthermore. the maximum pressure usually is limited by the choice of material used for sealing the glass to the metal, and by the strength of the glass itself. In the interest of increased efficiency of observation, as much of the cell as possible should be visible to the eye. Glass capillary tubes have been used successfully but have always given difficulty at the metal-to-glass seal. An apparatus has been devised to overcome the problems of sealing and resistance to temperature effects that have heretofore been the limiting factor with glass apparatus in the observation of phase volumes at elevated temperature and pressure. APPARATUS The objective which dictated the general arrangement of the apparatus (Figs. 1 and 2) was simplicity of operation. The air bath, A, was constructed of an iron framework to which was attached approximately one inch of glass wool bats which were covered on the outside with "Masonite." A roughly octagonal center piece was installed to provide forced circulation of the air by the fan, B, past the heaters, D, cell, F, and thermoregulator, C, respectively. The entire top of the box is removable to facilitate charging of the cell and to permit easy maintenance. Two windows are provided before and behind the cell to allow the operator to observe the contents against the background fluorescent light, E. The heaters,

Jan 1, 1951

TO THE BOARD OF DIRECTORS AND MEMBERS OF THE AMERICAN INSTITUTE OF MINING AND METALLURGICAL ENGINEERS GENTLEMEN Submitted herewith are the report of the Treasurer for the year 1937 and the reports for the same year of the following standing committees: Admissions, Membership, Papers and Publications, Library, Student .Relations, Speakers for Local. Sections and Student Societies, and Mining and Metallurgy. To these reports members are referred for further details. Finances.-Income for the year was the largest since 1930, the figure being $189,394, an increase of $18,803 compared with income for 1936, exclusive of a special Rocky Mountain Fund appropriation of $2500 in that year for visits to western schools and Local Sections. Major items of increase were: $8,000 from current dues and arrears; $7,700 from advertising in MINING AND METALLURGY and the two periodical "Technologies"; and $4,800 from sales of TECHNICAL PUBLICATIONS (pamphlets) and TRANSACTIONS volumes for both current and former years. Initiation fees and clues from new members declined $2,300, principally because of the larger 'proportion of Junior Members to Members among the new enrollments. Junior Members pay no initiation fee and dues are $10 compared with $15 for Members.

Jan 1, 1938

By H. A. Buehler

The Ozark region occupies a large part of the southern half of Missouri, the northern portion of Arkansas and comparatively smalll areas in northeast Oklahoma, southwest Kansas, and southern Illinois. It is a roughly elliptical plateau which has been deeply dissected by stream erosion, and which slopes imperceptibly into the prairie regions to the north, east, and west, but which terminates rather abruptly along the Arkansas River on the south and Tertiary lowland to the southeast. The Boston Mountains extending for a distance of some 200 miles (321 km.) along the Arkansas River rise to an elevation of 2000 ft. (609 m.), forming the most prominent topographic feature of the region. The so-called St. Frangois Mountains in St. Frangois, Madison, and adjoining counties in southeast Missouri, form a prominent but more restricted topographic feature, the highest point rising to an elevation of 1800 ft. (548 m.). The remainder of the region is largely a plateau area varying from 800 to 1500 ft. (243 to 457 m.) in elevation. Stratigraphy The region is underlain chiefly by sedimentary formations, which outcrop in roughly concentric bands around a comparatively restricted area of igneous rocks in the St. Frangois Mountain district. Although located geographically near the eastern edge of the Osarks, the St. Frangois Mountains have apparently suffered the greatest orogenic movement and the lowest formations of the succession are exposed in their immediate vicinity. The various sedimentary formations of the region do not show any considerable metamorphism and have suffered little change since consolidation. With the exception of a few basic intrusions in Ste. Gene-vievg County and a pegmatite dike in Camden County, Missouri, there is no evidence of igneous action, since the first sedimentary beds were deposited.

Jan 1, 1918

By J. E. Tobey, David R. Mitchell, J. H. Kerrick

DETAILED knowledge of purchase specifications established by coal consumers is essential to the successful design and operation of a coal-preparation plant. ANTHRACITE Specifications should be considered by both the consumer and the producer as guide posts outlining a certain path for both to follow. Plants differ, therefore specifications must differ to meet the varied requirements. Specifications are not of themselves a "cure all" or an assurance of complete satisfaction in fuel utilization. Specifications should not be regarded as a license to engage in an orgy of buying any and all coals that may happen to fall within their limits. This would lead to the-indiscriminate mixing of coals which may vary in their burning characteristics. Different coals of equal grade tend to be individualistic in their burning characteristics. Rather, specifications should be used to help simplify coal selection, to reduce the actual number of coals used over a given period; in other words, to have a stabilizing influence on coal or customer turnover. In the final analysis, the use of too many coals per year in a plant is costly to both the consumer and the producer. Too many sources usually result in higher operating and maintenance costs for the consumer and higher sales costs for the producer. Finally, the statement included in the report accompanying the comprehensive Coal Selection Charts prepared by the Coal Committee of the National Association of Purchasing Agents, and released in 1938, is significant. This Committee worked diligently for a period of 15 years seeking to find a scientific and reliable method for selecting coals. The two following paragraphs are quoted from its report: More important is the fact that no ready-made classification or set of specifications can possibly replace the judgment and resourcefulness of an experienced combustion engineer, or fuel technologist, nor the usual need for full scale plant tests under the exact conditions of use before a final decision is made . . .

Jan 1, 1943

By W. M. Weigel

WHILE electric lamps both of the cap and hand type are being introduced into many mines requiring the use of safety lamps, the oil-burning safety lamp is still used in the great majority of cases, and even where the former are used the latter must continue to be employed when testing for gas. It is not the intention to discuss here the relative merits of the two types, but simply to give a comparison of the illuminating effect or candlepower of several kinds of ordinary safety lamps used for general work and for testing. Few data have been published in recent years on this subject and because of this it is hoped that the following information may be of some interest and value. The lamps tested were in all cases. of standard size and in good condition, all practically new, and were selected from a collection of about 100 with a view to obtaining results on as many different common types as possible. With the exception of the gasoline-burning lamps, five different oils were used in each lamp to determine whether -particular oils were suited to particular lamps and whether there was any great difference in the illuminating power of the different oils, or whether some oils would maintain their illuminating power better than others throughout a working period of 8 hr. No attempt was made to determine the amount or cost of oil burned by each lamp, but the condition of the lamp, wick, glass, and gauzes was noted after each test.

Jan 8, 1916

By R. Maddin, N. Ujiiye

ALTHOUGH the cold-rolled texture for body-centered-cubic metals and alloys is well known (see, e.g., Barrett'), the pole figure representing the texture may be interpreted in two ways. It may be regarded as consisting of several ideal preferred orientations with an associated spread (a view which is shared among several investigators2), or it may be regarded as consisting of two sets of continuous preferred orientation also with an associated spread."." Recently, Chen and Maddin7 noted a stable (001) [loo] end orientation for molybdenum single crystals rolled at low rates of reduction provided the initial rolling. orientation" was close to the cube ori-

Jan 1, 1957

By N. Brown, H. Green

The effect of quenching temperature and of aging temperature and time on compression stress-strain curves of ß brass was investigated. Age softening occurs at a rate which decreases with decrease of quenching temperature below the critical temperature for ordering. The activation energy for softening is 15,400 cal per mol. No matter how rapidly brass is quenched or what the temperature from which it is quenched, practically complete order is obtained at room temperature. It has been demonstrated that with respect to the specific heat,',' electrical resistivity," X-ray diffraction, and microstructure, the slowly cooled and rapidly quenched specimens are the same and that complete long range order exists in both cases. However, Smith" showed that the hardness of ß brass depended upon the cooling rate and the temperature from which brass is quenched. Smith showed that the hardness was a maximum for specimens quenched from about 445 °C and that the as-quenched structure softened at room temperature at a rate depending upon the temperature prior to quenching. This softening after quenching is in this paper referred to as age softening. The results of this investigation are qualitatively the same as the findings of Smith. However, a more detailed analysis of these phenomena has been possible since the stress-strain curve offers a more sensitive index of the state of the metal than hardness. It is the purpose of this paper to show how the mechanical properties are related to the ordering of ß brass. A 200-lb ingot made from electrolytic copper and electrolytic zinc was extruded to 1/2in. rod. Chemical analyses at frequent intervals along the rod showed that the alloy contained 51.5 pct Cu with the greatest impurity being iron, at 0.01 to 0.001 pct. To obtain a constant test material, the 1/2in. extruded rod was warm-rolled to % in. diameter at 200°C and then recrystallized to a grain size of 2.0 mm. The specimens for the compression test were % in. high and % in. in diameter. The specimen ends were polished on 600 metallographic paper and coated with Molykote for a lubricant. The compression rig consisted of an anvil resting on the machined table of the Baldwin Southwark testing machine and a plunger fixed to the movable cross

Jan 1, 1954

By Reed W. Hyde

SOME information has been published on the sulphur dioxide concentration of gases from Dwight-Lloyd machines sintering lead ores but most of this relates to the customary practice in which the charge is relatively high in lead and is sintered in two passes over the machine. It is thought, therefore, that the following observations on sintering in one pass a low-lead, low-sulphur charge may be of interest. The data were obtained in sintering lead sulphide flotation concentrates mixed with minus 20-mesh oxide ore, the mixture carrying 16.8 per cent Pb and 5.3 per cent S. No returns were used because of the limited amount of sulphur available as fuel, but the mixture pelletized readily to make a satisfactorily permeable bed on the sintering machine. As there was a possibility that the SO2 might be utilized, a series of runs was made to determine the concentration of S02 in the gases at different points along the wind box, and the effect on this concentration of changes in the wind-box vacuum. Several runs each were made with vacuums (as measured in inches of water at the wind box) of (1) 2 to 1 1/3 in., (2) 4 to 3 1/2 in. and (3) 6 to 5 1/8 in. The averages of the determinations from each series are platted on the graph (Fig. I). The vertical scale shows the percentage by volume of SO2 (as determined by the Reich method), and the horizontal scale shows the time expressed as percentage of the total sintering time. Sintering was considered to be complete when no S02 could be detected in the gases. In all cases the depth of bed was 4 ½ in. and the weight of dry charge per square foot of hearth area was 45.2 lb. Other data are given in the table. The volume of gases corresponding to the several points along the wind box at which S02 determinations were made could not be measured, but has been calculated from the S02 content and sulphur elimination on the assumption that the volume is uniform throughout the sintering period. This is not strictly true, as with a given vacuum the volume will usually drop slightly toward the middle of the period and increase toward the end. However, this assumption is a reasonable approximation. Several interesting features are brought out by these data. In general, the published data on S02 concentration in sintering under ordinary conditions show a high S02 concentration in the early stages followed by a rapid decrease in concentration and with relatively little SO2 in the gases from the last half or third of the operation. In other words, the greater part of the sulphur elimination is obtained in the first third or half of the period. In these runs, the 6-in. vacuum, which approximates the usual operating condition, gives a curve that follows this customary pattern. Maximum S02 concentration is obtained 2 ½ min. after

Jan 1, 1942

By John R. Spencer

A capillary tube variable volume cell is described, which has operated satisfactorily over a range of 100°F and 3,500 psi to 550°F and 1,500 psi. The cell contents are entirely visible over the length of the capillary with the exception of a space at the top amounting to three per cent of the total volume. Observations on the critical behavior of simple systems have been greatly facilitated by the apparatus, it being possible to establish the critical conditions for a particular mixture in the course of a day's run. INTRODUCTION Many types of apparatus have been designed for obtaining data on the phase relationships of hydrocarbon systems. Such apparatus can in general be subdivided into two classifications; (l), indirect measurement of phase volume, and (2), direct visual observation of phase volume, each of which has outstanding advantages and disadvantages. Indirect measurement of phase volume requires the use of rather elaborate apparatus including internal probes in which are located the device for determining the locus of the interface between phases. Such equipment is by its very nature costly, and is complex from the standpoint of operating technique. Probing techniques can be used, however, over wide ranges of temperature and pressure with a high degree of reproducibility. Apparatus for visual observation of phase behavior obviously has the advantage of enabling the experimenter to see exactly what takes place, but because the material to be tested is contained in a cell constructed of both metal and glass, is limited severely as to the temperature range of operation. Furthermore. the maximum pressure usually is limited by the choice of material used for sealing the glass to the metal, and by the strength of the glass itself. In the interest of increased efficiency of observation, as much of the cell as possible should be visible to the eye. Glass capillary tubes have been used successfully but have always given difficulty at the metal-to-glass seal. An apparatus has been devised to overcome the problems of sealing and resistance to temperature effects that have heretofore been the limiting factor with glass apparatus in the observation of phase volumes at elevated temperature and pressure. APPARATUS The objective which dictated the general arrangement of the apparatus (Figs. 1 and 2) was simplicity of operation. The air bath, A, was constructed of an iron framework to which was attached approximately one inch of glass wool bats which were covered on the outside with "Masonite." A roughly octagonal center piece was installed to provide forced circulation of the air by the fan, B, past the heaters, D, cell, F, and thermoregulator, C, respectively. The entire top of the box is removable to facilitate charging of the cell and to permit easy maintenance. Two windows are provided before and behind the cell to allow the operator to observe the contents against the background fluorescent light, E. The heaters,

Jan 1, 1951

NEW MEMBERS The following list comprises the names of those persons who became members during the month of February, 1914: Members ASANO, KOSAKU, Vice-Mgr..: Ashio Copper Mine, Shimozuke, Japan. BIRD, FRANK H., Constr. Engr E. 417 Sixteenth Ave., Spokane, Wash. COLES, HENRY 0., Chem Copper Queen. Cons. Min. Co., Bisbee, Ariz. COLLEY, HYLTON H., Met Copper Queen Cons. Min. Co., Douglas, Ariz. DALEY, MITCHELL J., Mill Supt Utah Apex Min. Co., Box 753, Bingham Canyon, Utah. FISHER, GEORGE EDWARD, Director, 3d Vice-Pres., Grasselli Chemical Co. 1551 East 115th St., Cleveland, Co. FRASER, EVERETT L., Mill Supt Tightner Mines Co., Alleghany, Cal. FRASER, WILLIAM L., Min. Engr North Star Mines, Grass Valley, Cal. FROLLI, ALBERT W. Min. Engr 216 North Main St., Salinas, Cal. GEARHART, FRANK B., Chief of Smelter Dept., N. J. Zinc Co., 405 Columbia Ave.. Palmerton, Pa.

Jan 3, 1914

By D. A. Dahlstrom

Application of the cyclone to separation of undesirable -200-mesh clay, silt, and high-ash fractions from coal slurries was found to possess many economic and process advantages. Up to 93.3 pct removal was attained at rates of 113 to 155 gpm per sq ft of cross-sectional area.

Jan 2, 1951

By Arthur Phillips, E. S. Bunn

During the past few years considerable interest has been shown in the study of fiber, and its effect, in wrought metals. Fiber has recently been defined as a "condition of parallelism of important lines or details in the structure."' Briefly stated, two distinct types of fiber are commonly encountered. One results from the alignment in the direction of working of constituents, more or less segregated, such as slag, oxides, carbides and dendritic formations. The second, and least understood, type is produced by working the metal below the recrystallization temperature in such a way as to develop a parallelism of the grains. This condition is readily recognized by the pronounced elongation of the grains in the direction of working. Under certain deformational treatments the grain fragments produced by cold working tend to orient in certain definite directions with respect to the axis of extension. Furthermore, even in metals that have been annealed after cold working preferred orientations may be present. It is perhaps logical to assume that such marked parallelism of structural elements would be manifested by directional properties in the metal. As a matter of fact, tests on many kinds of materials have shown differences in varying degrees. In recognition of this condition, proper design, for many purposes, places the fiber axis in such a way as to present the direction of maximum strength to the greatest applied stress. Earlier Investigations Howe2 has written at considerable length regarding the causes and practical significance of fiber in steel and wrought iron. His studies showed that wrought iron and the puddled steel sheets (materials of plastic origin) were weaker transversely than longitudinally. The transverse deficit ranged from 5 to 29 per cent. The longitudinal tests

Jan 1, 1931

By AIME AIME

AN IMPORTANT innovation in Alabama in the semi-longwall type of coal mining as applied to low-dipping thin seams has been introduced by the Galloway Coal Co., mining the Mary Lee high-ash seam which averages only 26 in. thick. The property is their Mill Creek mine, near Carbon Hill, Ala., in the Warrior coal field. The results, although not final, indicate that roof conditions can be successfully handled by this method without loss of walls, with a rate of recovery much above that possible with the room-and-pillar method, and at the low production cost necessary for this grade of coal. Double cross-headings are turned off a main haulageway on 60-ft. centers and driven 40 ft. wide with thin chain pillars between. These double entries are turned at 525-ft. intervals, leaving a solid block of coal 440 ft. across; that is, from the outside of one pair of headings to the inside of the next pair is 440 ft. The bottom, which consists of hard fireclay, is taken in these entries 8 ft. wide and 4 ft. deep for head room.

Jan 1, 1934

By R. W. Bartlett

The rates of oxidation of tungsten have been determined at temperatures between 1320" and 3170°C and oxygen pressures to 1 amn using a surface -recession measurement technique. Above approximately 2000°C and 10-6 atm the rate is independent of temperature and can be calculated from gas collision theory assuming a constant reaction probability, e, of 0.06. Oxygen molecules react at surface sites where oxygen atoms have previously chemisorbed. This provides a direct pressure dependence at low pressures but at high pressures tungsten oxide molecule s form an adjacent gas boundary layer which lowers the PO2 at the tungsten surface. A correction for this effect using free-convection theory fits the rate data over the entire oxygen-pressure range from 10-8 to 1 atrn as well as data using O2-A mixtures. Below 10-6 atrn and above 2000°C, e decreases with increasing temperature because of desorption of oxygen atoms. Below 2000°C the rate decreases with decreasing temperature at all oxygen pressures following an apparent activation energy of 42 kcal per mole and depending on (Po2)n with n varying between 0.55 and 0.80. MOST of the previous tungsten oxidation studies have employed gravimetric methods and have been limited to temperatures below 1000°C where the weight loss associated with evaporation of tungsten oxides is negligible compared with the weight gain from oxidation.' At higher temperatures, oxygen-consumption rates have been determined from pressure measurements, usually at constant flow rates, by Langmuir,2 Eisinger,3 Becker, Becker, and Brandes,4 and Anderson.5 The sensitivity of this method decreases with increasing pressure and, with the exception of Langmuir's work, these investigations were confined to pressures below 10-6 atm. Above approximately 1300°C, depending on the oxygen pressure, the rate of oxide evaporation is greater than the oxide-formation rate and the recession of the tungsten surface can be measured optically without interference from an oxide layer. This was first done by Perkins and crooks6 who heated tungsten rods in air pressures from 1 to 40 torr at temperatures between 1300" and 3000°C. The present investigation of the oxidation kinetics of tungsten at high temperatures emphasizes oxygen pressures from 10-6 to 1 atm. This is the range of interest for earth atmosphere re-entry applications of tungsten for which little data were previously available. APPARATUS The apparatus is a modification of the type used by Perkins and crooks.' Ground tungsten seal rods, 6 in. long by 0.125 in. diam, were mounted vertically between two water-cooled electrodes, one fixed and the other having free vertical travel. The movable counter-weighted electrode is prevented from undergoing horizontal displacement by three sets of runners mounted at 120-deg intervals. Electrical contact is made by means of a water-cooled mercury pool. A 24-in. vacuum bell jar having a volume of approximately 267 liters was used as the reaction chamber with the sample holder mounted in the middle of the chamber. Power was supplied from an 800-amp dc variable power supply. Temperature readings were made by means of a Latronics automatic two-color recording pyrometer. With this instrument, corrections for emissivity are not necessary provided the spectral emissivi-ties at two closely spaced wavelengths are equal. Supporting measurements were made with a micro-optical pyrometer corrected for emissivity of bare tungsten and window absorptivity. The micro-optical pyrometer was calibrated against a National Bureau of Standards calibrated tungsten lamp and both pyrometers were periodically checked against the melting points of tungsten and molybdenum using the oxidation apparatus. Above 10-6 atm, pressures were measured with an Alphatron gage calibrated against a McCleod gage. At 10-6 atm, a hot-filament ionization gage was employed. A magnified image of the self-illuminated tungsten rod was formed using a 360-mm objective lens mounted outside the bell jar. When the experiment exceeded 1 hr, the image was focused on a ground-glass plate about 10 ft from the tungsten rod at about X8 and the recession of the thickness of this image was monitored with a Gaertner cathe-tometer. When faster rates were encountered, a 35-mm time-lapse cinecamera with a telephoto lens and bellows extension was substituted for the ground-glass plate and cathetometer. Diameter recession rates were determined from the photograph image projected on the screen of an analytical film reader. EXPERIMENTAL PROCEDURE After installing the rod in the apparatus and cleaning it with acetone, the system was evacuated to 5 1 x 10-5 torr. Before oxygen was introduced,

Jan 1, 1964

By J. B. Hiskey

Heap leaching has in recent years been established as an important processing alternative for gold and silver. Currently, heap leaching accounts for about 25% of primary mine produced gold and 10% of primary silver. This paper reviews gold and silver heap leaching practice and surveys major operations in the United States.

Jan 1, 1984

Abbey, Robert Graham, District Mgr.. The W. W. Sly Mfg. Co., 50 Church St.. New York, N. Y. '21 Abbott, A. N., Mines Supt., Mazapil Copper Co., LtdConcepcion del Oro, Zac., Mexico. '28 *Abbott, Argyle Campbell, Dev. Dept., E. I. du Pont de Nemours & Co., Wilmington, Del. '29 Abbott, Clarence E., V.P., Charge of Raw Materials, Tenn. Coal, Iron & R. R. Co., 1242 Brown-Marx Bldg.. Birmingham, Ala. '04 Abbott, Louis Benjamin, Chief Engr., Elkhorn Div., Consolidation Coal Co., Jenkins, Ky. '16 Abeel, George H., Jr., Cons. Min. Engr Box 427, Santa Monica, Cal. '18 Abel, Albert E., Asst. to Pres., Valley Mould & Iron Corp Hubbard, Ohio. '19 Abel, Raymond L., Asst. Prof., Dept. of Pet. Refin., Univ. of Pittsburgh Pittsburgh. Pa. '28 Abeel, Leo M., Research Engr., Sullivan Concentrator Chapman Camp, B. C., Canada. '31

Jan 1, 1929

By F. G. Smith

A few years ago, the writer encountered a problem that, at first, seemed to be due to peculiar conditions affecting grain growth. Large cups made from heavy metal failed in the first drawing operation in the process of making seamless tubes. The metal, as cast, appeared to be sound and strong; it rolled successfully and withstood the first cupping operation, but on the first draw it failed, with a crystalline fracture. The failure appeared in the slightly worked part of the bottom of the cup, and microscopic examination revealed exceptionally large grains. Knowing the general conditions governing recrystallization of brass, which were later published by Mathewson and Phillipsll an investigation was outlined with the idea of including various conditions under which new grains might form, and which would include the effect that a previous anneal might have upon the anneal following. These conditions were produced by annealing specimens of brass at five different temperatures, indenting them with a 10-mm. ball under four different pressures, and then reannealing at each of the five temperatures five specimens each of which had been annealed at one of the five temperatures. Preparation of Specimens The material used was cartridge brass 0.400 in. thick, having the following composition: Copper 66.60 per. cent., zinc 33.35 per cent., lead 0.02 per cent., iron 0.03 per cent. This was rolled with 35 per cent. reduction after a 700" C. anneal. Fig. 1 shows the structure of this original bar on which all subsequent anneals were made. Pieces 1 in. (2.5 cm.) wide and 3 in. long were prepared and annealed for 1/2 hr. at 450°, 550°, 650°, '750°, and 850" C. Each of these pieces are indented under the Brinell test with a 10-mm. ball at 500, 1000, 2000, and 3000 kg. pressure. Then, sets of five pieces from each of the original anneals were reannealed at 450°, 550°, 650°, 750°, and 850" C.

Jan 1, 1921

By C. E. Abbott

THE Birmingham district, Alabama, is distinctive in the proximity to one another of its deposits of iron ore, coal and flux. These three basic requisites for the making of iron and steel are found within a radius of 10 miles. Both dolomite and limestone are produced, the former for blast-furnace flux and the latter for basic open-hearth operations. The Tennessee Coal, Iron and Railroad Co., a subsidiary of the United States Steel Corporation, operates a limestone mine at Muscoda, near Bessemer, 12 miles southwest of Birmingham, served by its own railroad transportation system. The mine has a capacity of 130 tons per hour. Average analyses of a recent month's production are as follows: Fe2O3 Si02 A12O3 CAC03 MGCO Lump, per cent 0.51 0.22 98.63 0.14 Crushed and washed, percent 0.70 0.26 98.36 0.18 Lump stone, 2 1/2 to 7 1/2 in., is used in open-hearth operations at Fairfield Steel Works. Fine crushed and washed stone, 1 ¼ to 0.063 in., is calcined at the, lime-burning plant and used for lime charges at the Ensley open hearths.

Jan 1, 1936