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By H. J. Hager, P. H. Haskell

For the past 20 years Alabama has probably led all other coal-producing districts in the proportion of coal prepared by wet washing. All rail mines, with one exception, and a high percentage of truck mines now wash all coal under 3 or 4 in. Most of this coal has been cleaned by jigs, though within the past few years one or more wet-table plants have been installed for cleaning some of the coal from practically all the major seams. These tables supplement either single or multicell jigs usually for one of the following purposes: (I) to wash the finer sizes of raw coal, (2) to rewash the finer sizes of washed coal after they leave the jigs, (3) to re-treat jig middling products. The main purpose of this paper is to present cleaning data and operating factors involved in the preparation by tables of the finer sizes of raw coal. The specific information and data pertain to the Mary Lee seam of coal as extracted at three of the mines of the Alabama By-Products Corporation, which produces coal for both byproduct coke-oven consumption and the general steam market. The Mary Lee seam has long been recognized by coal-preparation authorities as presenting a very difficult ash-reduction problem. Washing characteristics and physical structure of the seam vary widely. Its thickness ranges from 32 in. with no rock parting to 100 in. with from one to three partings. Over the entire field the bed contains bands of bone and rash. These are distributed throughout the seam cross section. A portion of this bone or bony coal occurs as definite bands I in. or more thick; however, some bone is interlocked as layers within the coal and consequently breaks into flakes when the coal is broken. This material is relatively high in ash and its specific gravity varies widely. It has been observed that in most cases in the washing of Mary Lee coal from 10 to 18 per cent of the raw coal is within +0.10 specific gravity of the attempted point of separation. Therefore with the average wet jig, only with extreme difficulty can a low-ash product be obtained without loss of much marketable coal in the refuse. Without entering into the controversial question as to whether modern washing equipment can efficiently handle simultaneously all sizes up to a given maximum, suffice it to state that the comparatively old-type jigs in service at the Alabama By-Products Corporation's mines could not clean the he sizes satisfactorily. Therefore, in 1931 that company installed six diagonal-deck tables at the Barney mine, which were installed as an addition to a complete plant cleaning all coal below minus 3 in. The primary washed product is shipped as steam coal and another portion may be prepared as washed nut for domestic trade. These tables are washing 9 tons per hour of raw coal sized to ¼ in. to o. The washed table coal is mixed with the 3 to ¼-in. jig product to constitute a 3 in. to o steam coal.

Jan 1, 1942

By H. J. Hager, P. H. Haskell

For the past 20 years Alabama has probably led all other coal-producing districts in the proportion of coal prepared by wet washing. All rail mines, with one exception, and a high percentage of truck mines now wash all coal under 3 or 4 in. Most of this coal has been cleaned by jigs, though within the past few years one or more wet-table plants have been installed for cleaning some of the coal from practically all the major seams. These tables supplement either single or multicell jigs usually for one of the following purposes: (I) to wash the finer sizes of raw coal, (2) to rewash the finer sizes of washed coal after they leave the jigs, (3) to re-treat jig middling products. The main purpose of this paper is to present cleaning data and operating factors involved in the preparation by tables of the finer sizes of raw coal. The specific information and data pertain to the Mary Lee seam of coal as extracted at three of the mines of the Alabama By-Products Corporation, which produces coal for both byproduct coke-oven consumption and the general steam market. The Mary Lee seam has long been recognized by coal-preparation authorities as presenting a very difficult ash-reduction problem. Washing characteristics and physical structure of the seam vary widely. Its thickness ranges from 32 in. with no rock parting to 100 in. with from one to three partings. Over the entire field the bed contains bands of bone and rash. These are distributed throughout the seam cross section. A portion of this bone or bony coal occurs as definite bands I in. or more thick; however, some bone is interlocked as layers within the coal and consequently breaks into flakes when the coal is broken. This material is relatively high in ash and its specific gravity varies widely. It has been observed that in most cases in the washing of Mary Lee coal from 10 to 18 per cent of the raw coal is within +0.10 specific gravity of the attempted point of separation. Therefore with the average wet jig, only with extreme difficulty can a low-ash product be obtained without loss of much marketable coal in the refuse. Without entering into the controversial question as to whether modern washing equipment can efficiently handle simultaneously all sizes up to a given maximum, suffice it to state that the comparatively old-type jigs in service at the Alabama By-Products Corporation's mines could not clean the he sizes satisfactorily. Therefore, in 1931 that company installed six diagonal-deck tables at the Barney mine, which were installed as an addition to a complete plant cleaning all coal below minus 3 in. The primary washed product is shipped as steam coal and another portion may be prepared as washed nut for domestic trade. These tables are washing 9 tons per hour of raw coal sized to ¼ in. to o. The washed table coal is mixed with the 3 to ¼-in. jig product to constitute a 3 in. to o steam coal.

Jan 1, 1942

For the year ending February, 1919 PRESIDENT SIDNEY J. JENNINGS NEW YORK, N. Y. PAST PRESIDENTS L. D. RICKETTS NEW YORK, N. Y. PHILIP N. MOORE ST. Louis, MO. FIRST VICE-PRESIDENT C. W. GOODALE BUTTE, MONT. TREASURER GEORGE C. STONE, NEW YORK, N. Y. SECRETARY EMERITUS ROSSITER W. RAYMOND, NEW YORK, N. Y. SECRETARY BRADLEY STOUGHTON NEW YORK, N. Y.

Jan 4, 1918

By John Suman

DURING the past few years the taking of cores in drilling with rotary equipment has been perfected to a remarkable degree in the Gulf Coast fields of Texas and Louisiana. Taking of cores is becoming quite a common thing, especially in the newer fields, and drillers are becoming expert in this work. The writer has seen cores 5 to 8 ft. long taken with great ease in wells as deep as 4500 ft. Coring is doing much to remove the prejudice which so many petroleum engineers seem to have against .the use of rotary drilling equipment for exploratory work. Some operators .are now claiming that when used with a reasonable amount of coring the rotary system is even more satis-factory than cable tools for exploring in certain territory. A case has recently been pointed out in the South Electra field of North Texas, where producing oil sands, passed over by cable-tool drillers, are being brought in with rotary equipment. It seems that in this particular territory the sands are rather thin. Cable-tool drilling was carried on for the most part in a wet hole and the red mud encountered in drilling caved into the hole very badly, so that the cuttings showed mostly red mud and the driller, thinking that the sand did not amount to anything, carried his water string through the sand. The later .operators, drilling into the sand with rotary equipment and coring it, found that it was well worth testing.

Jan 10, 1922

J. E. Johnson, Jr., Glen Wilton, Va. (communication to the Secretary*):—Mr. Meissner announces early in his paper that one of its purposes is the discussion of my paper entitled, Notes on the Physical Action of the Blast-Furnace,' with which he disagrees in part; and as the second stage of the discussion of this important subject has centered around his paper, some reply by me may not be amiss. Unfortunately, Mr. Meissner has not indicated a single statement or conclusion in my paper that he wishes to controvert; but as there is evidently a difference of opinion between us I will disregard this fact, and will discuss those conclusions of his that seem to me not to be justified by the facts of general practice, or even by the data which he produces to support them. Let me say, however, that I am a believer in the dry-air

Jan 1, 1908

The Library of the above-named Societies is open from 9 A.M. to 9 P.M. on all week-days, except holidays, from September 1 to June 30, and from 9 A.M. to 6 P.M. during July and August. The Library contains about 55,000 volumes, including sets of technical periodicals and the publications of scientific and technical societies. Members of the Institute, with few exceptions, are forced to spend a portion of their time in localities isolated from sources of information. To these the Library can render valuable service through correspondence; letters requesting information will receive special attention. The Library is prepared to furnish references and copies of articles on mining and metallurgical subjects; to determine the existence of mining-maps, and to furnish general information as to the geology and mineral resources of all countries. All communications should be made as definite as possible so that the information received may be what is desired and not include collateral matter which may not be of interest. The time spent in searching for such collateral matter will be saved, and the information will be sent more promptly and in more usable-shape. The members of the Institute can be of service to the Library by forwarding copies of mining-reports, maps privately issued, and similar material, which will be classified, indexed, and made available to other members. Suggestions for additions to the Library, either by purchase or personal solicitation as gifts, will be welcomed. It is hoped that members while in the city will use the Library freely, and assurance is given that most careful service will be rendered to them.

Jan 2, 1914

By B. E. Field

COBALT is a silvery white metal with a slight bluish cast, strongly resembling nickel in its appearance and properties, notably its resistance to corrosion, although its alloys with other metals differ quite decidedly in their properties from those of nickel. The name cobalt was derived from the German "Kobold" meaning goblin and this came to be applied to the cobalt minerals which, although they resembled ores, did not readily yield metal when smelted by the primitive processes available in the Middle Ages. Cobalt minerals were used as pigments by potters and glass workers before the Christian era. Cobalt blue glass was found in the tombs of the Egyptians and in the ruins of Troy, and many colors used by the ancient Greeks and Romans contained cobalt. The ancients were entirely unaware that the colors they used were caused by cobalt and the metal itself was only isolated about the middle of the eighteenth century by Brandt although the preparation of cobalt compounds had been carried on in a small way ever since the opening of the silver-cobalt deposits at Schneeberg, Germany, in 1470. The metal is fairly hard, with a density when pure of 8.81 in the cast state and 8.92 after working. The com¬mercial grade of cobalt has a density of about 8.75 in the cast state. The atomic weight is 58.97. The Brinell hardness of the pure metal is 124; that of the commercial grade varies from as low as 100 to as high as 138, depending upon the impurities present. Pure cobalt has a sharp melting point at 1478°C. The tensile strength of the pure metal in the cast condition is said to be higher than that of any other pure metal. Kalmus gives it as 34,400 lb. per sq. in. for cast unannealed metal; the effect of annealing at 850 to 900°C. is to raise the strength slightly. The yield point is close to the ultimate strength and the reduction in area and elongation are both low. Mechanical working raises the tensile strength of pure cobalt rapidly and in the form of wire it will be over 100,000 lb. per sq. in. The presence of small quantities of carbon in the commercial metal raises the tensile strength to as high as 61,000 lb. per sq. in., the reduction in area and elongation being raised at the same time to approximately 20 per cent.

Jan 1, 1933

By J. F. K. Brown

ANTHRACITE in 1943, in common with the coal industry as a whole, passed through a year of wage negotiations that seemed endless. In the early months discussion of the United Mine Workers' demands was taken up and carried on continuously until May, finally reaching an impasse when the Union refused to continue at work, while submitting their demands to the War Labor Board. Thus a strike threatened, averted by the Federal Government taking over the industry, effective May 1, by order of the President. An office of the Bureau of Mines was established in Wilkes-Barre under the direction of J. J. Forbes, Mineral Production Security Division, as regional manager, who conducted operations until September, 1943, when the collieries were turned back to the operators. But the miners did not agree with the War Labor Board's award rendered in the fall, resulting in a recurrence of the previously threatened strike. again averted by Government control. In addition to the major upsets, a number of individual suspensions occurred at various mines. In spite of these drawbacks, to which might be added the difficulty of obtaining equipment and the scarcity of man power, the industry by November was only little less than a million tons short of the previous year. and in all probability, finally produced but little less than in 1942. This little less. however, was greatly missed in the market.

Jan 1, 1944

The Army Reorganization Act, which became effective July 1, 1916, contains a provision authorizing the organization of an Officers' Reserve, in which will be included a Corps of Reserve Engineers. There will also be an Enlisted Reserve of skilled workmen in technical lines. The special provisions of the bill relating to the Engineer Officers' Reserve were formulated with the help of the Joint Committee of the several national engineering societies, which has been at work on the matter for over a year with the War Department and Committees of Congress. Recognizing that engineering science is the basis of success in modern

Jan 8, 1916

By P. H. Mell

AMONG the minerals exhibited at the Atlanta Exhibition of 1881, soapstone, kaolin, and asbestos were well represented. The first two occur in large quantities, of very pure quality, throughout the South. The last is somewhat limited in amount, yet in certain localities it exists in masses sufficiently large to pay for working; in North Carolina, Georgia, and Alabama it has been mined with some profit. I would, in this paper, call special attention to the minerals soapstone and kaolin, because their many valuable qualities seem to have been al most entirely overlooked by our Southern manufacturers. Steatite, particularly, occurs in such large quantities, and generally in such close proximity to the great iron regions of Alabama and Georgia, that it is amazing that the iron companies will persist in sending abroad under. heavy expense for firebrick. It would require a much smaller sum of money to quarry this rock and place it at the various furnaces ; and the results obtained, I am sure, would prove its superiority over the majority of firebrick brought into this region. Soapstone, as well as kaolin, is found throughout the metamorphic regions of Alabama, Georgia, South Carolina, and North Carolina. Below-will be found seven analyses that I have made of this mineral, taken from various points in the four States above mentioned. I have also subjected these same specimens to severe fire-tests, and the results were very satisfactory. The tests were conducted in the following manner: Small portions of the compact variety were carefully weighed and placed in a Fletcher's new crucible furnace for gas, and subjected for half an hour to a heat that will in 12 minutes fuse iron. The only effect upon these specimens was a slight change in color .to a darker shade, a small loss in weight, due evidently to the evaporation of water, and, in one or two specimens, a slight degree of fusion on the sharp edges. The first specimen subjected to investigation was taken from a large outcropping in Tallapoosa County, Alabama. Specific gravity, 2.88 ; hardness, 1.9; color, blue gray. Composition Water, - 2.68 Silica, - 65.46 Iron oxide, - 2.10 Alumina, - 15.02 Magnesia, - 15.35 100.61

Jan 1, 1882

By C. G. Dunn, F. W. Daniels, M. J. Bolton

IN recent investigations1. a data on relative grain boundary energies in silicon iron have been obtained. The present investigation is a continuation of this work along similar lines for the purpose of obtaining additional information on boundary energies. One aim has been to extend the data for a (110) series, which was formerly studied,' to small differences in orientation, since a recent theory3,4 based on a dislocation model of grain boundaries predicts a E. ? (A-ln ? )* form of energy curve for small differences in orientation. Another aim has been to provide data for a (100) series—all grains having (100) planes parallel with the surface of sheet speci-mens—and to compare the results with the predicted form of energy curve. Finally, information on the nature of approach to equilibrium conditions was to be obtained through observations on the movements of grain boundaries. Recently published papers2,3,5 have treated the mathematical problem of expressing equilibrium conditions for grain boundaries for the general case when boundary energy depends upon boundary orientation. The equilibrium equations, which relate equilibrium angles and grain boundary -free energies, contain additional terms that express the variation of energy with boundary rotation. It has been necessary in the present investigation, however, to neglect these additional terms since no data for their evaluation were available. Dropping the additional terms leads to the following approximate equations which were used: E12/sin ?3 = E18/sin?2 =E28/sin?1 or those of the form: E28 + E13 cos ?3 + E12 cos ?2 = 0 Experimental Procedure Except for sample F1, all specimens were made from two lots of silicon iron called C and L respectively. The compositions of these are listed in table I. In the preparation of 12 three-grain specimens for the present investigation, a controlled grain growth technique, which has been described previously,' was used. After preparation, the specimens were notched at the boundaries to shorten them as a means of providing more rapid approach to equilibrium in the anneals. Initial grain boundary angles were determined from micrographs taken at X500. Seven anneals, totaling about two days at 1300°C and two to four days at 1400°C, were run in an atmosphere of pure dry argon as described in a previous paper.' Boundary changes generally could be followed without metallographic surface preparation, because thermal etching occurred during the anneals. These observations indicated angle changes of as much as 35" in some instances, with the major changes occurring during the first anneal. Annealing was discontinued when the angles reached stationary values. Fig. 1 gives a schematic diagram for purposes of defining crystallographic and boundary directions for three grains with common plane parallel with the sheet. Differences in orientations (expressed by A) are the angles between [00l] directions. They can be calculated with the aid of the ?'s. The grain boundary angles can be calculated from the w'S. Results Results are given in table 11. Types of crystal-lographic planes refer to those parallel with the sheet. Orientations are given in terms of [00l] direc-tions as shown in fig. 1. Except for grain 3 of specimen H6, which was unintentionally tilted 7" out of a (100) plane, all grains generally were within 1" or 2" of the plane specified. The directions of boundaries were measured generally to within 1" on both upper and lower surfaces, and the average direc- tions were determined for use in calculating the grain boundary angles. Variations in grain boundary directions refer to deviations from average directions. Boundaries near the junction point for all specimens generally were very close to perpendicu-

Jan 1, 1951

By M. van Swaay, C. E. Birchenall

A. S. lBrling (Johnson, Matthey & Co. Ltd., Laboratories)— Because of its initial emphasis upon the production of membranes by powder metallurgy and by normal casting and rolling techniques, this paper is of considerable interest to those concerned with the design and application of industrial diffusion units. As the subsequent performances of the three grades of palladium were not compared in detail, it can perhaps be concluded that specific permeabilities were very similar. A short table in which the absolute diffusion rates obtained by the Authors with their three grades of palladium were compared with those of other investigators18-25 would, however, have been of particular value in view of the very variable results obtained with this membrane material. The Authors state early in the paper that the permeability of the thoriated samples decreased in much the same way as that of the nonthoriated samples. Later, they emphasize that sintered palladium without thoria was very susceptible to poisoning and did not respond as well as the other materials to the decontamination treatment. These results, which suggest that sintered membranes are less effective than those produced by normal methods, have considerable industrial implications, and amplified experimental details would be very welcome. The results of the Authors differ in one important respect from those of other investigators. Thus, no "bleeding" was required to maintain a constant rate of diffusion, although Davis, Darling, and De Rosset found this to be necessary. Davisz3 found that "bleeding" was necessary even when the hydrogen had already been purified by diffusion through a palladium tube, and it would be of value to know the purity of the gas stream emerging from the purification train shown on Fig. 1 of the Authors' paper. The Authors show that diffusion rates varied according to the square root of the pressure difference providing that the palladium membrane was not contaminated in any way. This finding is in agreement with the results of those workers2,18,19,23,24 who diffused their hydrogen through the membrane into a partly or completely evacuated system.Those workers who did not find this square-root law dependence did not have a partial vacuum on the downstream-side of the membrane.'' The difference between the two experimental con- ditions appears to be significant, as the absolute diffusion rates per sq cm of diffusion area are lower when the square-root law dependence is not observed. While the effect could be attributable to poisoning of the membrane it is conceivable that a positive pressure on the downstream side of the membrane might influence the mechanism of diffusion. In view of the capricious behavior of palladium, factors of this type, which are likely to influence its industrial significance, should be carefully considered. M. van Swaay and C. E. Birchenall (authors' 9-eply) — Our Eq. 191 may be compared with several others for hydrogen diffusion in palladium: D = 5.95 x exp (-5770/1)' D = 3.55 x 10"3 exp (-5550/)' D = 4.3 x 10"3 exp (-5620/1')' Other values are given in the literature, but in many cases surface poisoning may have affected the results. No analysis was performed on the hydrogen gas stream after purification. It should be noted that the presence of liquid nitrogen traps near the heated membranes may have set up convection currents and provided the equivalent of "bleeding." The question of whether a partial vacuum existed on the downstream side of the membrane is not clear. Does it imply that there is something unique about the permeability measured near one atmosphere pressure? We do not believe that there is. When square root pressure dependence is not observed, diffusion rates are not measured. Is "absolute diffusion rate per sq. cm. of diffusion area" equivalent to permeability? The terminology is new to us. In any case we doubt very much that pressures of the order of several atmospheres can affect the mechanism of diffusion.

Jan 1, 1962

By K. Tangri, M. Chaturvedi

The addition of 0.5 wt pct Cu to Zr-2.5 Cb alloy increases the as -quenched hardness of the hexagonal martensitic a' phase, produced by water-quenching bccß-Zr phase, by about 35 pct. This strengthening has been attributed to the solid -solution hardening of the matrix. On aging ternary martensite, a' phase reverts to equilibrium a and Zr2Cu and ß-Cb precipitate out, mainly at the twin and grain boundaries, causing a secondary hardening of the matrix. COLD-worked Zircaloy-2 pressure tubes have been in use in power reactors for a considerable period of time. The search for a better material led to the development of Zr-2.5 wt pct Cb alloy which in the quench-aged condition develops 50 pct more strength than that of cold-worked Zircaloy-2, however, its corrosion resistance in water and steam in the temperature range of 316" to 400°C, in absence of neutron flux, is inferior to that of zircaloy-2.' Work carried out by Ells et al.1 and Dalgaard2 has shown that the corrosion properties of Zr-2.5 wt pct Cb alloy can be considerably improved by the ternary addition of 0.5 wt pct Cu. This paper is concerned with the effect of 0.5 wt pct Cu on the formation of martensitic a and its aging characteristics in a Zr-2.5 wt pct Cb alloy. MATERIALS AND EXPERIMENTAL TECHNIQUES Zr-2.5 Cb-0.5 Cu (referred to as the ternary alloy) and Zr-2.5 Cb (referred to as the binary alloy) alloys, supplied by the Chalk River Nuclear Laboratories of the AECL were used. The detailed chemical analysis is given in Table I. Cold rolling and swagging with frequent intermediate anneal of 1000°C were used for the initial fabrication of the alloys. All the heat treatments were carried out after the specimens were wrapped in zirconium foils and encapsulated in silica tubes under a vacuum of 5 x 10-6 mm of Hg. For optical metallography and hardness measurements specimens were mechanically and then chemically polished in a 45 pct HNOj, 45 pct HzO, and 10 pct HF solution. Hardness was measured on a Vickers hardness tester using a 10-kg load. For each specimen at least fifteen indentations were made in order to obtain a representative value. The phase identification and structural analysis were carried out using X-rays and electron diffraction techniques. Wires of 1.5 mm diam reduced to 0.12 mm diam by chemical etching were used for making Debye-Scherrer powder patterns using Cu Ka radiation in a 114.6 mm diam camera. Carbon extraction replicas were prepared by etching the specimens, after depositing a layer of carbon on the metallographic specimen, in one part HF and thirty parts ethyl alcohol. Thin films were prepared by electropolishing heat-treated 3/4 by 1/2 by 0.005 in. thick strips using a modified Bollman-Window technique. The 10 pct perchloric acid-90 pct methyl alcohol bath was kept at -50°C and polishing was done at 5 to 10 V. The thinned specimens were washed in ethyl alcohol at -30º to -40°C and dried between filter papers. Replicas and thin films were examined in a Phillips 300 G electron microscope. For resistivity measurements thin strip specimens 0.02 by 0.3 by 10.0 cm long were used. The potential leads were spot welded to the specimens in order to maintain a fixed length for the initial and the final resistivity measurements. The resistivity was measured by a Kelvin bridge in a temperature controlled room. The temperature was maintained at 72º ±1°F and the accuracy of the resistivity measurements was 0.03 µa-cm. RESULTS As-Quenched Structures. In order to produce a homogeneous matrix to study the precipitation reaction the solution-treatments of both the alloys were carried out in the -field region. From the Zr-Cb phase diagram due to Lundin and cox3 ß/a + ß phase boundary for Zr-2.5 wt pct Cb alloy is 820°C. Ells et al.1 have reported this boundary for Zr-2.5 Cb alloy containing 1100 ppm 0 to be at 920°C. Also, the addition of 0.5 wt pct Cu reduces this temperature by 50°C. Therefore, the solution-treatments were carried out at 1000°C to ensure that the alloys were in ß-phase region. The soaking time was 1 hr and the specimens were water-quenched. The as-quenched hardness of the binary alloy was 245 Vpn whereas, that of the ternary alloy was 330 Vpn. The X-ray diffraction studies indicated that the as-quenched structure of both the alloys consists of martensitic hexagonal phase a', with a c/a ratio of 1.591, and some retained ß-Zr. The presence of a' phase was further confirmed by thin film electron microscopy. Electron micrographs of typical ß-quenched structures of the ternary and the binary alloys are shown in Figs. 1 and 2, respectively. Fig. 3 shows the diffraction pattern from an area similar to that shown in Fig. 1. Although, the as-quenched hardness of the ternary alloy is about 35 pct greater than that of the binary alloy, the structure of both the alloys seems to be the same. The matrix of both alloys is heavily twinned and shows very few dislocations. Furthermore, there is no evidence of any precipitation taking place in either of the two specimens during quenching from the solution-treatment temperature. Aging Behavior of Martensitic a'. The aging kinetics of the ternary alloy were followed by resistivity and hardness measurements. The as-quenched values

Jan 1, 1970

By K. Stout, L. Friel

Some rock mechanics theorists believe that if a hydraulically placed backfill can be introduced in a stoped out area, which will minimize wall closure by taking high stresses across the fill with minimum compaction, then heavy ground and rock burst phenomena will be minimized. The paper will discuss a large scale laboratory project when fill strength was increased over four times by the head vibrated method and up to well over 20 times by the double placed, cemented, vibrated head method when compared to conventionally placed fills. The only preconditioning of the 60% solids by weight slurry was the addition of cement in some tests.

Jan 1, 1983

By James Terry Duce

The symposium on production for the year 1940 contains few papers on the foreign situation. It is probable that the foreign part of next year's symposium will be even shorter. This is due to rigid censorship in various countries, as the question of the volume of petroleum supplies has become one of great strategic importance. This is even more true than in the last war, owing to greater mechanization of armies. 'It has always been the policy of officers in charge of the symposium to refrain from publishing information that might possibly injure national or private interests. At the close of the war we hope again to publish full and accurate records of production abroad. Excerpts from Circular to Authors In order to facilitate interpretation of the data in this chapter, we print the following excerpts from the Circular to Authors. The field is the unit in this tabulation. In cases of fields extending across State boundaries, such as Rodessa, it is suggested that each State author treat the section of the field in his State as a unit, and by a footnote indicate that the field extends into an adjacent State. Each space in Table I may represent one of four possibilities; either it is not applicable to the particular field, or the proper entry is not determinable, or the proper entry may be determinable but is not determinable from data available to the author, or the proper entry is determinable. When spaces are not applicable, leave blank; in spaces where the proper entries are determinable but not de-terminable frod data available to the author, please inserty; in spaces where the proper entries are determinable by the author, make such entries. y implies a hope that in some future year a definite figure will be available. The entry of a zero is a positive declaration, and an important declaration where it is in order. Inability to determine precisely the correct entry for a particular space should not lead the author to insert merely y. Contributions of great value may be made by the author in many cases where entries are not subject to precise determination. In sucli cases the author should use his good judgment and make the best entry possible under the circumstances. For many spaces the correct entries represent the opinion of the author (for example, "Area Proved') and in such cases the entry need not be hedged to such extent as when the quantities are definite yet can be ascertained only approximately by the author. In cases under definite headings but where figures are only approximate, the author may use x. It is thought that the nearest whole numbers are sufficiently accurate for our purposes except as to percentage of sulphur in oil. If an author desires to report any other figures to tenths, he may do so. The quantity of gas produced should include, where possible, gas sold or otherwise marketed, and gas blown into the air, burned as flares or otherwise wasted. Segregation of these figures would be interesting if the authors can make such segregation. In any event, the figures should represent as nearly as possible the total quantity of gas removed from the reservoir. Under the columns on "Depth," the average depth to the top of the productive zones and to the bottom of the productive wells, when

Jan 1, 1941

INTO their great Pacific Northwest counting house went the members of the Industrial Minerals Division recently, to count their blessings amidst the scenic grandeur and mineral wealth of the State of Washington. From their vantage point in Seattle, those who attended the IMD's fourth Pacific Northwest meeting turned their sights to the South and Southeast, scanned Montana, Idaho, Oregon and Utah, and predicted a very healthy economic future for their region. The praises of Idaho's booming phosphate industry were sung by Earl W. Murphy, secretary of that State's Chamber of Commerce. He said the establishment of Fort Hall, on the banks of the Snake River near Pocatello, first turned the eyes of the world toward what is now the center of the greatest known deposits of phosphate rock-the section adjacent to the common corners of Idaho, Wyoming and Utah. With the founding of Fort Hall, Mr. Murphy said, historians will also rank the construction of the first electric furnaces for the production of elemental phosphorous as equally significant in the commercial history of the West. Those furnaces were installed only last year by the Westvaco Chemical Div. of the Food Machinery & Chemical Corp. at Pocatello, at a cost of $8 million.

Jan 7, 1950

Jan 1, 1940

By M. E. Wadsworth, K. C. Bowles, H. E. Flanders, R. M. Nadkarni, C. E. Jelden

The kinetics of precipitation of copper on iron of various purity were carried out under controlled conditions. The rate of reduction has been correlated with such parameters as copper and hydrogen ion concentration, geometric factors, flow rate, and temperature. The character of the precipitated copper as a function of flow conditions and rate of PreciPitation has been observed under a variety of conditions. ThE precipitation of copper in solution by cementation on a more electropositive metal has been known for many years. Basile valentine' who wrote Currus Triumphalis Antimonii about 1500, refers to this method for extraction of copper. Paracelsus the Great2 who was born about 1493 cites the use of iron to prepare Venus (copper) by the "rustics of Hungary" in the "Book Concerning the Tincture of the Philosophers". Agricola3 in his work on minerals (1546) tells of a peculiar water which is drawn from a shaft near Schmölnitz in Hungary, that erodes iron and turns it into copper. In 1670, a concession is recorded4 as having been granted for the recovery of copper from the mine waters at Rio Tinto in Spain, presumably by precipitation with iron. Much has been published in recent literature on the recovery of copper by cementation, the majority of the articles being on plant practice.5-24 The rest include articles on investigation of the variables involved25-28 and a review of hydrometallurgical copper extraction methods." This literature has established: a) The three principal reactions in the cementation of copper are Cu + Fe — Fe+4 +Cu [ 11 One pound of copper is precipitated by 0.88 lb of iron stoichiometrically. In actual practice about 1.5 to 2.5 lb of iron are consumed. 2Fe+3 + Fe — 3Fe+2 [21 Fe +2H'-Fe+2 + H2 [3] Reactions [2] and [3] are responsible for the consumption of excess iron. Wartman and Roberson'28 have established that Reactions [ I] and [2] are concurrent and much faster than Reaction [3]. b) Acidity control is important in the control of hydrolysis and the excessive consumption of iron. he commercial workable range is approximately from pH = 1.8 to 3." c) Iron consumption is closely related to the amount of ferric iron in solution. Jacobi" reports that, by leaving the pregnant mine waters in contact wi th lump pyrrhotite (Fe7S8) for 3 hr, all the iron was reduced to the bivalent condition and scrap iron consumption was cut to 1.25 lb scrap per pound of copper precipitated. He also reported that SO2 has been used successfully to reduce ferric iron to the ferrous state. d) The ideal precipitant is one that offers a large exposed area and is relatively free of rust. e) High velocities and agitation show a beneficial effect upon the rate of precipitation, as it tends to displace the layer of barren solution adjacent to the iron and also dislodges hydrogen bubbles and precipitated copper to expose new surfaces. Little work, however, has been published on the reaction kinetics of copper precipitation on iron. Cent-nerszwer and Heller20 investigated the precipitation of metallic cations in solutions on zinc plates. They found the cementation reaction to be a first-order reaction. The rate constant was independent of stirring for high stirring rates and they concluded that the rate is governed by a diffusional process at low stirring speeds and by a "chemical" process at higher stirring speeds where the rate reaches a constant value. This conclusion has been challenged by King and Burger30 who could not find any region where the rate was independent of the stirring speed, although the rate constant they had obtained for high stirring speed was greater than the maximum value of the rate constant reported by Centnerszwer and Heller (by a factor of six). King and Burger, therefore, concluded that the rate of displacement of copper was controlled only by diffusion. Cementation of various cations on zinc has been summarized by Engfelder.31 APPARATUS A three-necked distillation flask of 2 000-mm capacity was used as a reaction vessel. A pipet of 10-mm capacity was introduced through one of- the side necks, the sample of sheet iron, mounted in a rigid sample holder, through the other, the stirrer being in the middle as shown in Fig. 1. The whole assembly was immersed in a constant-temperature bath. The stirrer was always placed at the same depth in the solution. EXPERIMENTAL PROCEDURE Reagent-grade cupric sulfate (J. T. Baker Chemical Co., N.J.) was used to make up a stock solution containing 10 g of copper per liter which was then diluted to various concentrations as required. Experimental data were obtained by measuring the amount of copper and iron ions in solution at successive time intervals. The initial volume of the solution was always 2000 ml, 10-ml aliquots being removed each time for chemical analysis. Because the total volume change of the solution was less than 10 pct, no correction was used for solution volume change. Nitrogen was bubbled through the solution before and

Jan 1, 1968

By Frederick C. Hull, Robert F. Mehl, Robert A. Colton

IT is known that pearlite forms from austenite by a process of nucleation and growth, and that the rate of formation of pearlite may be described by a rate of nucleation and a rate of growth.1,2 The manner in which these two quantities operate to produce the observed isothermal reaction curve has been analyzed in a paper published in 1939.3 Two types of process were described: (1) that in which nucleation occurs at the grain boundaries of the parent phase, with the nodules growing toward the centers of the grains, initially as hemi¬spheres and then after impingement as roughly radial-columnar structures; and (2) that in which nucleation occurs generally, with the nodules growing to full spheres until impingement with other growing nodules restricts growth. Both cases are met in the formation of pearlite from austenite (Fig. 1);2.4 the former, occurring near the knee of the S-curve has been named "grain-boundary transformation," and the latter, occurring at temperatures near Ae1, has been named "group-nodule transformation." In developing our knowledge of the factors that determine the rate of formation of pearlite from austenite, it is important 1,2 to obtain data on the rate of nucleation and the rate of growth of pearlite. Such data, when obtained near the knee of the S-curve, will furnish information of use in understanding the factors that affect hardenability; when obtained at higher temperatures, such data will be useful in understanding the behavior of steels that during heat-treatment react to pearlite.2 It is the purpose of this paper to present data on the rate of nucleation and the rate of growth of pearlite in dependence upon composition, grain size, temperature, and the degree of homogeneity of the parent austenite. The studies are restricted chiefly to plain carbon commercial steels.* PREVIOUS DATA ON RATE OF NUCLEATION AND RATE OF GROWTH Data on the rate of nucleation and the rate of growth of pearlite have been published by Scheil and Lange-Weise,5 by Mirkin and Blanter,6,7 by Mehl,1 and by Dorn, De Garmo and Flanigan.2 It is difficult to interpret the data, for in most cases too little information is given on austenitizing temperatures and times, the state of homogeneity of the austenite (presence or absence of carbide, etc.), austenite grain size, and mode of formation of pearlite at the temperatures given.

Jan 1, 1942

By K. F. G. Hosking

I read Professor Gaudin's paper with great interest and pleasure because for some time I have held that the chemical aspect of comminution is a subject of considerable importance to the mineral dresser and deserves to be thoroughly investigated. It does seem appropriate, however, to emphasize the fact that "fresh" edges and corners produced by the grinding of solids display enhanced reactivity has been recognized and utilized in the development of certain mineral identification techniques. Some of these techniques are worth noting, not only because they might facilitate research in the aspect of mineral dressing under discussion, but also because they emphasize the fact that many mineral species commonly regarded as being very inert can display a surprising reactivity when in the freshly ground state. In 1951 Isakov published a number of tests for the components of certain mineral species which depend essentially on grinding in a mortar a mixture of the material under investigation with a solid reagent. Thus when stibnite, 4(Sb2S,), is ground with sodium or potassium hydroxide, the antimony is revealed by a momentary development of a yellow color which changes in air to orange-red. Other antimony minerals need a preliminary treatment before the test can be carried out. This consists of grinding with aluminium sulfate, ferric sulfate or potassium bisulfate, and breathing upon the resultant mixture.

Aug 1, 1956