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By H. W. Wainwright

One phase of the research and development work on synthetic liquid fuels conducted by the Bureau of Mines at Morgantown, W. Va. in cooperation with West Virginia University deals with the purification of synthesis gas.2/ Most of the experimental studies on gas purification have been directed toward the removal of organic sulfur from gas, either catalytically or by adsorption with activated carbon. An important part of the purification program has been the development of suitable analytical methods for determining organic sulfur compounds. As the total sulfur content, organic and inorganic, of purified synthesis gas should not exceed 0.1 grain per 100 cubic feet, the need for accurate analytical methods is apparent. It is also apparent that such methods must be rapid if one wishes to evaluate various processes for removing sulfur from gas. The organic sulfur found in most gas produced from coal is usually present as carbon disulfide, carbon oxysulfide, methyl and ethyl mercaptans, and thiophene, with the exception of thiophene, the remaining organic sulfur compounds respond similarly to catalytic treatment and can be removed effectively. Not only does thiophene resist most catalytic treatment, but it poisons some catalysts, rendering them ineffective in removing the other forms of organic sulfur.

Jan 1, 1950

By H. R. Page, A. E. Jr Lee

A. E. LEE, JR. (author)—In addition to the paper we should like to make a few remarks. First, the seriousness of bending of the clay retort cannot be overemphasized. Not only did bending limit the length of the vessel, but it permitted corrosive fluid slags to concentrate in the belly of the retort and thus increased the possibility of boring. Bending also practically prohibited the use of cleanout machines and increased the danger of excessive fume losses by allowing furnace gases to escape around the top of the retort mouth. It will be noted that the Blackwell pottery practice places considerable emphasis on careful drying of retorts. Perhaps it is another smelter superstition, but traditionally the aging of retorts beyond a reasonable drying period has been considered important to long life. We are unable to give a good explanation of why aging should improve retorts. During the past fall in an attempt to prove a theory that the combined water in the clay decreased during aging, about 50 samples of wet retort collars were placed in a dry room when it was closed. Loss of weight, combined water and free moisture were measured each week over the 100 day drying period. The affinity of the dried retort for moisture makes difficult the accurate measurement of free water; however, there was a clearly defined free moisture change from about 12.5 pct when freshly made to about 2 pet at the end of 18 days, then a gradual loss to about 0.25 pet at 70 days and an apparent equilibrium near this figure through the 100th day. There was no appreciable change in the combined water. The change in weight of the average sample was, however, rather unusual, there being consistently a loss of weight throughout the entire 100 days. From the 63rd day on this leveled off to about 0.03 pet per week. These were small samples and certainly should have dried

Jan 1, 1950

Capital, as represented by mineral resources, is being exhausted rapidly without possibility of identical replacement. The public must be discouraged from thinking-why worry about the bank balance so long as there are plenty of blank checks? Instead of each man, woman, and child being owners of a mineral capital of $89,000 as former Secretary Ickes once stated, they are really the guardians of a mineral reserve which, when harvested, cannot be reproduced. The proper use of this material is the basis of modern civilization and military power. The best American institutions cannot be maintained or transmitted to our children unless this trust is guarded. It is unfortunate that more attention has not been focused on the fact that this country is headed for a have-not status in the family of great nations if some- thing is not done to preserve its mineral heritage. It is the privilege of the United States now to champion and implement democracy because it is industrialized and can get at its raw materials. A high price is being paid every day in mineral depletion for the privilege. No one can eat his cake and have it too. The United States still must face world-wide economic competition and, perhaps, World War III. In the final analysis all wealth comes from the ground, whether plant, animal, or mineral. Value is in-

Jan 1, 1950

By H. R. Page, A. E. Jr Lee

From the inception of zinc retorting on a commercial scale in the United States in 1890,' the retort employed has undergone wide variations in its composition and manufacture, facilitating in part equally remarkable improvements in furnace capacities. The early day hand made clay retort was charged with carbonates or silicates or with coarse dead roasted concentrates mixed with a large proportion of charge fuel resulting in a relatively low zinc burden and fired 24 hr in direct coal fired furnaces. Its modern counterpart is fabricated in hydraulic presses from clay mixtures containing sizeable amounts of either silicon carbide or silica flour, charged with sintered flotation concentrates to more than three times the early day zinc burden and fired 24 to 48 hr in gas fired furnaces. This paper does not attempt to describe in detail the early day clay retort practice as it is well outlined in treatises by Ingalls,2 Lodin,3 Liehig,4 Hofman5 and others. A brief review of clay retort practice is presented together with a description of the major developments since 1912. Clay Retorts The Belgian type retort, both in the circular and elliptical forms, has been used almost exclusively. Typical dimensions of press made clay retorts around 1910 are shown in Table 1. Variations in these dimensions were used at different plants according to local conditions to a maximum inside diameter of 9 in. and inside length of 54 in. However, the effective heat penetration in a 24 hr firing cycle and the tendency of the retort to bend limited the retort size. Use of the elliptical vessel was an attempt to present a stronger cross-section resisting the tendency to bend and to increase the burden without increasing the depth of heat penetration. One exception to the 48-54 in. length was the 60 in. retort used as early as 1905 at Palmerton by means of supporting the last 12 in. at the butt end with a specially designed furnace back-wall. This backwall construction with the 60 in. retort had been developed and used at Bethlehem by G. G. Con-vers and A. B. DeSaulles. An attempt was made at Blende, Colo. to use even larger retorts of the Rhenish type based on European practice and requiring much higher furnace temperatures. Satisfactory plastic clays capable of withstanding these temperatures were not available, and the plant never operated successfully. PREPARATION OF BATCH Composition of the clay retort by weight was 40 to 50 pct raw clay and the balance "grog." Generally speaking the mix consisted of 7 parts plastic clay to 9 parts grog by volume. Principal source of the clay used was the Cheltenham vein—sometimes referred to as "St. Louis city clay." A typical analysis was A12O3-31.0 pct, SiO2-50.0 pct, Fe2O3-2.5 pct, MgO-0.3 pct, CaO-1.5 pct and loss on ignition 14.0 pct. At the smelter the clay was weathered whenever possible and then crushed to 0.08 in. or finer. Grog consisted of calcined adobies, cleaned retort scrap and cleaned refuse fire brick such as old furnace brick, blast furnace linings, and others. Saggers from ceramic plants and calcined flint clay were later used. The grog materials were ground to 0.12 m. or finer. Occasionally coke dust up to 10 pct of the mix was substituted for a part of the grog following European practice.² Particle size of the grog has a major influence on the retort properties—the larger the grain, the better can the retort withstand thermal shocks, resist bending at furnace temperatures and resist corrosion from slag; the smaller the grain, the lower the loss of zinc vapor through the retort walls. Grog forms the skeleton of the retort, and the clay shrinks around its grains to act as a binder. In the drying process, the grog has a stabilizing effect on the drying rate, decreasing shrinkage and giving up previously absorbed water to the surrounding clay to minimize the danger of cracking or checking.² Grog and clay were mixed through a horizontal pug mill with 10 to 20 pct water added, depending on whether the retort was to be formed by hand or mechanically, more water being required for the hand process. The batch or "mud" extruded from the pug mill was cut in convenient lengths for handling, stacked in piles or in special rooms, covered with wet burlap and allowed to "rot" or age from 1 to 8 weeks to increase plasticity. HAND MOLDING If the retort was to be molded by hand, the mud was repugged after the rotting period and given to the molders. Their molds consisted of 3 sheet iron or wood cylinders, each one third the retort length and defining the outer shape of the retort. Beginning with the bottom section, mud was placed in the form and tamped with a rammer

Jan 1, 1950

By Chas. A. R. Lambly

In the extreme northeast corner of the State of Washington, on the Canadian border, lies the Metaline mining district. This district is old in history, but young in production. Geology The Metaline district is a zinc-lead area of the replacement type in dolomite and limestone. The ore bodies of the Josephine horizon are in many ways similar to the ore bodies of the famous Tri-State zinc fields. The beds are faulted and folded and have varying low dips in varying directions, and underlie large areas of the district. History Production started in 1927 on a very limited basis. The property is now mining and milling 700 tons per day. The mine is opened by adit tunnels and a vertical shaft. As the ore horizons gained depth, it was necessary to sink inclines to follow the ore horizon (see Fig 1). From 1927 to date, approximately 600,000 ft of diamond drill was put down This work indicated that suficient tonnage existed to justify a redesigning of the whole operation, surface and underground. After four years of general study, the following program was planned: 1. A new mine entrance, which would be an incline, that could follow the ore body down at whatever pitch was necessary. The incline will be equipped with conveyors for the moving of ore and waste to the surface and with tractor-type locomotives for man and supply transportation. 2. The new incline also required a new type of mining which was developed and is now in use. It is called contour mining and will be described in a future paper. 3. The new incline exit would necessitate the moving of the mill and mine shops across the Pend Oreille River. This part of the program is now underway. The Incline The sinking of the incline was to start as soon as World War II ended and was as follows: The first leg of the incline was to be sunk from the surface 1600 ft on a 17" slope. The collar and first level at elevation 2180 ft, the second level at elevation 2000 ft, the third level at elevation 1875 ft, and the fourth level at elevation 1700 feet. From the 1700 ft elevation the incline was to flatten out to 12" for 400 ft to give the necessary depth for the ore pockets below the 1700 ft level and the necessary clearance for future sinking (see Fig 1 and 2). Due to lack of manpower in 1946, the program was changed and was as follows: A drift was driven from the old mine workings on the 1700 ft elevation in an easterly direction. At 1300 ft the drift was turned N 50" E and at this point a raise was driven 180 ft on a 50" slope. This raise intersected the Josephine horizon and commercial ore was encountered. At the 2000 ft mark, a main raise was driven, 245 ft on a 50" slope, and the 1875 ft elevation was cut. Exploration drifts were started on this level and production followed on a limited basis. The main drift at the 2500 ft point was turned N 35" E and ran parallel to and 10 ft east of and under the proposed incline line. At the proposed intersection of the drift and incline on the 1700 ft elevation, it was planned to raise the incline to intersect the 245 ft raise and to continue on to the surface, a distance of 1600 ft. When this proposed intersection point was reached, a heavy flow of water, approximately 800 gpm, was encountered and all work on the main drift face was stopped. This water flow flooded the main pump station in the old mine and the two lower levels with approximately 20,000,000 gal of water. The water was controlled and finally drained from the cave areas and lower levels after six months of pumping. After the heavy flow of water was encountered in the main heading, it was decided that the incline would have to be started from the surface, as originally planned, so that too much time would not be lost. The surface overburden had to be removed, a total of 6000 yards. A temporary dry house for 6 men was built. An 8 in. churn drill hole was intersected in the first raise driven from the 1700 foot elevation tunnel. Air and water lines were placed in this hole, and air and water were delivered to the collar of the incline from the mine working. The incline started down at 15 ft wide and 7 ft high through the Leadbetter slates. After sinking 4 sets, it was

Jan 1, 1950

By John H. Soule

The Royal John mine was examined in November 1942 by a mining engineer of the Bureau of Mines, who proposed development of the Royal John and other properties in the area. Geologists of the U. S. Geological Survey studied the area in 1943 and 1944 and made definite recommendations. Also, in 1943 the Peru Miring Co. mapped the Royal John and did considerable diamond drilling. The Bureau of Mines started the Royal John portion of a project pertaining to the general district in April 1944. This project was completed in Juno 1945. The work, consisting of diamond drilling, was supervised by Robert O. Hill, mining engineer, and the results were published in Report of investigations 3904, Exploration of Grey Eagle, Grandview and Royal John Claims, Grant County, N. WIC. In 1947 and 1948 the Royal John was re-examined by a Bureau engineer, and additional development to increase the reserves of low-grade lead-zinc ore was proposed. This project was started in August 1948 and completed in Juno 1949.

Jan 1, 1950

By Albert L. Toenges

Alaska requires an adequate fuel supply for its development, and has large potential coal reserves ranging from lignite to subbituminous and anthracite. Coal production in the Territory now is less than the requirements. In L947, production was 361,000 tons, divided about equally between bituminous coal from the Matanuska field and subbituminous coal from the Nenana field. There is need for development of modern mechanized mines, which should produce the required output with a minimum of workers. These mines should not be thought of in the light of large potential capacity, as in the States. However, these new mines should be developed by modern methods, which should result in lower costs than at Present. Because of the diverse physical conditions in the coal fields, intensive investigation by diamond drilling is necessary to properly plan the development and equipment of mine sites at minimum cost. The Bureau of Mines is doing this now in the Wishbone Hill area of the Matanuska field. All coal land in Alaska is government-owned and subject to the Coal Leasing Act. Coal mining in Alaska has been handicapped by an inadequate supply of dependable workers. Wage scales have been very high in recent years, and "floaters" have been attracted to the coal mines. This type of labor is not conducive to efficient operation. Modernization of mines will require skilled and dependable workers and to induce such men to become interested in coal mining in Alaska, modern facilities, such as modern houses, schools, churches, and recreation halls, must be provided near the mines. Alaska is still a frontier and improvements in living standards must accompany development of mines in order that a stable community may be established. Coal is known to have been mined in Alaska at Port Graham, on Cook Inlet, by the Russians in 1854. During the Klondike gold rush in 1898, coal was mined in scattered areas for use on steamers plying the Yukon River and its navigable tributaries. After the Alaska Railroad was built, two important fields were developed—the Nenana and the Matanuska (Fig 1). The Bering River field was explored by the Guggenheim interests at one time, and a railroad to the area was constructed. However, the field was abandoned because of litigation and reported unsatisfactory physical condition of the beds. There are areas that today are unimportant but which may be developed in the future. Possibly the most important of these is the deposits of subbituminous coal adjacent to Cook Inlet, near Homer, on the Kenai Peninsula (see Fig 1). It is expected that the demand for coal in the Kenai Peninsula will increase because the population in that area has increased as a result of agricultural development. Numerous outcrops of coal are exposed on the peninsula and development of a mine there would obviate dependence on supplies of coal from the Matanuska field. Coal from this field must be shipped approximately 160 miles by rail to Seward and transported thence by boat about 180 miles to Homer. There has been no regular boat service from Anchorage to Homer. There are deposits of coal in the Arctic region but a description of them will not be given in this paper, which will describe the more important deposits in the Alaska Railroad belt. The results of a reconnaissance in the Arctic have been described.' Description of Fields MATANUSKA FIELD The Matanuska field lies in the valleys of the Matanuska River and its tributaries and their separating ridges. This field has been interpreted by geologists as a sunken fault block that separated the Talkeetna Range of mountains from the Chugach Range. The Matanuska River flows west along the south side of the field and the Glenn highway, which extends from Anchorage via Palmer to the Richardson highway near Glen Allan, follows the Matanuska Valley. This road to the coal field can be traveled the year around. Although the snow-

Jan 1, 1950

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

Recent observations on grain boundary movements in sihcon iron have indicated the possibility of studying grain growth phenomena in two-grain specimens in which several variables affecting growth are readily controlled. These variables are (1) the energy per unit area (?) in the grain boundary, (2) the orientation relationship of the two grains, and (3) the radius of curvature (7) of the moving boundary. Ideally, one grain A should be a narrow rectangular parallelepiped adjacent to a second grain ß as shown two dimensionally in Fig 1. Such a two-grain group becomes unstable when one end of grain A is shaped according to the dotted line. Since the width w of grain A remains constant during growth of grain B, T should also remain constant. The other vari- ables mentioned above can be controlled in the preparation of each two-grain specimen.l,2,3 For a parLicular orientation of each grain, is not necessarily fixed; ? may also depend on the orientation of the grain boundary, but this may be controlled to some degree. The energy relationships for the gowth of grain ß may be derived from the more simple arrangement of two grains A' and B' shown schematically in Fig 2. Here B' largely surrounds A'. Assume these grains are oriented with a common plane parallel with the flat

Jan 1, 1950

By Josiah Royce

To evaluate chemically the sample of rock obtained by diamond drilling, it has long been recognized that the analyses of the two components of the sample, core and sludge, must be given appropriate influence in computing the average analysis of any unit of depth. The purpose of this investigation is to set forth what means are available for apportioning the effect of core and sludge on the final analysis, what variables affect the problem, and what combination of applied mathematics will closest approximate the truth under each condition as these variables proceed within their limitations. A drill hole is bored in iron ore exploration principally to test variations in rock composition with depth and is usually directed as nearly normal to the bedding of a horizon to be tested as possible. This practice has a tendency to minimize variation in composition laterally which in any event is not likely to be great. It is obvious that the opportunity for change in analysis of a particular rock is not statistically as great radially in a diamond drill hole where the distance in which such a change may occur is from 0.719 in. (EX bit) to 1.469 in. (NX bit) as there would be longitudinally even in a' run as short as 5 ft. Variations in composition of bedded or layered rocks are usually greater normal to the bedding than parallel thereto. Even in massive rocks, like porphyries, variations are functions of distance. Hence. in either case, variations along the hole are of greater effect than across it. Let us examine Fig 1 briefly to observe a cross section of a unit of depth of a typical diamond drill hole. If we neglect radial change in chemical composition, which we have seen is small compared to lengthwise variation, we can see that if core recovery was 100 pct, the core and its surrounding area, which would be recovered as cuttings (assuming 100 pct sludge recovery), must analyze the same if the sampling is perfect. This is the foundation of this paper, namely, that if core recovery is complete we may assume that the core constitutes as nearly as possible a perfect sample of the ground drilled. Now let us pass to the methods of weighting core and sludge in the final analysis and then develop each in turn. One might employ core analyses only, sludge analyses only, or apportion the influence of each by one of several methods. The most common apportionment is by direct proportion to relative theoretical vol- ' ume occupied by each component in the cylinder hollowed out by the drill, known as the Longyear formula. Another logical treatment would be to consider core and sludge in the final analysis according to the weight of each recovered. This procedure was elaborately set forth and refined by R. S. Moeh1man.l Then to be sure that we have embraced all the possibilities, we must admit that some other method or methods may be devised empirically or by mathematical maneuvers. Should a drill machine be capable of recovering 100 pct of the core in all types of rock, certainly core alone need be analyzed and no complicated mathematics are required; but although some companies have had fair success in obtaining high percentages of core in certain homogeneous ores on the Mar-quette Range, their same methods have proved disappointing on the Menominee, Cuyuna, and Gogebic Ranges where the iron formation often varies widely from flinty chert beds interstratified with soft hematite to wholly leached ore material composed of an unpredictable mixture of hematite and limonite with occasional zones of sugary, recrystallized chert. In spite of numerous mechanical improvements in core barrels, few drilling programs can count on complete core recovery. The sludge alone might be analyzed but for practical reasons this is inadvisable when core is obtained due to the numerous opportunities for contaminating or losing portions of the cuttings. The Longyear formula involves a weighting of the core and sludge in proportion to the theoretical volume of each, that is, where the volume of the core recovered is one-third of the total cubic volume of the cylindrical hole made by the drill, the analysis of the core is given one-third of the weight in the final analysis. This approach to

Jan 1, 1950

By Grover J. Holt

Open-pit mining on the iron range has been in a stage of transition for several years from the standpoint of mechanization. The most radical change in open-pit mining methods was started in open-pit haulage in 1937 with the departure from the then standard system of locomotive and car transportation and the advent of the heavy duty truck as a replacement. The initial use of trucks was followed shortly by the first installation of a conveyor belt for open-pit ore haulage. The growth of the combination of trucks for gathering units delivering to a conveyor system for transportation out of the pit, has been rapid and this transition appears to have reached a peak in 1949 with locomotives and cars now being used in only a few of the largest open pits. One point which must be considered, if we assume that the maximum equipment change- over point has been reached, is that the largest pits have probably passed their peak of production. Future ore replacement must come from smaller pits wherein the truck conveyor system has done an outstanding job.

Jan 1, 1950

By Ming-Kao Yen

S. E. MADDIGAN*—I think Mr. Yen should be complimented on doing a very excellent and a very comprehensive piece of work. I was particularly pleased to note the use of X rays in a somewhat less tedious technique than pole figures. In the past I think many workers have been diverted away from the use of X rays in such investigations because of the large amount of work involved in pole figures if one is dealing with a great number of specimens. The same thing, I think, applies to the determination of orientations by counting of twins which is also a very tedious procedure; as a result several papers which have otherwise been of excellent quality have depended upon etching techniques for determination of orientation. The present paper indicates that the results reported in those previous papers were correct, but I think the use of etching techniques alone is a rather shaky basis for setting up theories in the literature. W. M. BALDWIN, JR.*—This discussion will be a short note of correction and apology. In my discussion of Brick, Martin and Angier's paper I incorrectly reported the orientation of phosphorus deoxidized copper annealed at temperatures. When I learned that Mr. Yen was preparing the present paper I asked that he correct this previous error, which he most graciously consented to do. However, through my ambiguity the correction noted on p. 59 of Mr. Yen's paper is still not the proper one. For this I take full responsibility. The orientation which I observed in phosphorus deoxidized copper at high temperatures is the (112) [111] which agrees with the pole figure given in Fig 8a, on p. 65 of Mr. Yen's paper. Our observations were made on the basis of twin counts rather than X ray determinations and therefore serve as an independent confirmation of Mr. Yen's data. M. K. YEN (author's reply)—The author wishes to thank Dr. Maddigan for his comments in regard to the application of glancing technique to textures. As a matter of fact, considerable work has been done recently in connection with

Jan 1, 1950

By S. A. Lever, R. Hultgren

(E. R. Jette and J. R. Long presiding) M. B. BEVER*—The method re- ported in this interesting paper promises to he of fairly wide applicability. It may be expected that the solidus and liquidus lines in other low-melting alloy systems can also be determined by resistance measurements. As these alloys are especi- ally slow to reach equilibrium, a static method will improve the accuracy with which these parts of their phase diagrams can be determined. It should be noted that the sensitivity of the method for the determination of

Jan 1, 1950

By J. H. Jackson, P. D. Frost, C. H. Lorig, L. W. Eastwood, A. C. Loonam

R. S. BUSK*—I wish first to congratulate the authors of this paper both for the work done and the presentation of that work. We have also been working on this type of alloy development, but any technical contribution I might have is better reserved for a separate paper which is planned in the near future. However, I would like to insert a word of caution. The alloys described in this paper are still very much in the laboratory stage. There still remains the quite vexing problem of property stability at slightly elevated temperatures which must be solved before the properties quoted can be effectively utilized. These alloys are extremely interesting and I am confident that the problems can be solved. However, the present existence of those problems must not be overlooked. I have one question with regard to the work-hardening test. If the work harden-ability of magnesium is compared to aluminum using a more standard test such as the Meyer Analysis the magnesium is found to work harden the more rapidly. Is the test developed for this work truly a work-hardening test or a measure of something else ? J. H. JACKSON (authors' reply)—I am sure we appreciate the comments of Mr. Busk and we are pleased that the Dow Chemical Co. has also undertaken work in this field. It is a big field. We, of course, are continuing our research for the Navy Bureau of Aeronautics, since, as clearly shown in the paper, the alloys are not completely developed. With regard to Mr. Busk's comments on the relative work-hardenability of aluminum and magnesium, the comparison we cited in the paper was intended merely to show that the results obtained by our method of testing were independent of the yield strength of the materials. We believe that this test method afforded a rough indication of the work-hardenability of the magnesium-lithium base alloys. It is not known whether this method affords greater or less accuracy than the Meyer Process, which is based upon a hardness-test impression. It is quite possible, since work-hardenability is a function of metal purity, that our results, obtained for commercial aluminum and magnesium, would be different if high-purity metals had been used. A. C. LOONAM—Lithium has some very interesting effects on magnesium. The paper showed that even small percentages increased ductility. These small amounts changed the axial ratio of the hexagonal magnesium from 1.624 in the pure metal to 1.606 in the saturated alpha solution, a value close to that of titanium, which has a ratio of 1.601. You will recall an article in the January, 1949, issue of the Journal of Metals where it was stated that titanium can be cold-rolled over 90 pct without any significant edge cracking. At 4.9 or 5 pct lithium, a change begins in crystal structure—from a hexagonal close packed to body centered cubic. There are two phases over a short range of lithium content, but at 10 pct the structure becomes completely cubic. The melting points of alloys in this range of lithium content are relatively high. Alloys even up to the six ratio have melting points above 500°C; this represents a relatively small reduction in melting point from pure magnesium itself. The magnesium-lithium system has a number of very interesting characteristics. This is only a very small part of the story. J. H. JACKSON—I would like to remind you that Mr. Loonam is one of the authors of this paper, and the fact is that this work is based on many of his ideas. I am sure we appreciate his additional comments in this discussion. R. LEITER*—I am interested in Fig 19 in which Mr. Jackson compares

Jan 1, 1950

By Carrol M. Beeson

Reasons are given for using a Boyle's-law porosimeter in conducting core analysis for either routine or research purposes. Among other things, it is pointed out that such a porosimeter permits the measurement of all basic properties on the same sample, thereby eliminating the sources of error inherent in the use of adjacent samples. References are made to investigations of gas adsorption on various porous materials, to show that the use of helium in Boyle's-law porosimeters reduces to negligible proportions the error due to the adsorption or desorption of the operating gas. Two Boyle's-law instruments are described. which permit accurate and rapid measurements of porosity. Schematic sketches and explanation:; are included, along with derivations of equations required in performing precise determinations. Summaries of data obtained during calibration are tabulated and analyses of the data are resented as indications of the precision and accuracy of each device. Comparisons are also shown for measurements made with each of the instruments on the same test pieces and cores. INTRODUCTION An accurate porosimeter, operating on the principle of Boyle's law. is of considerable value in the analysis of cores for either routine or research purposes. This is due primarily to the fact that the measurement of porosity with such an instrument leaves the sample free of contamination by any liquid. When used in conjunction with an extraction apparatus' for determining oil and water saturations, a Boyle's-law porosimeter permits the measurement of all basic properties on the same sample. This eliminates the sources of error inherent in the use of adjacent samples, or the necessity of determining porosity after all other properties have been obtained. Large errors may result from combining measurements made on adjacent samples in order to obtain a single property. This type of error is definitely involved when oil and water are measured with one sample, and the pore vo1ume is measured with an adjacent one. Furthermore, the source of error would be present to some extent, even if the analyst could choose the samples so they were truly adjacent from a geological standpoint. The use of adjacent samples in routine core analysis also necessarily decreases the probability of correlating core properties. For example, the chance of correlating the "irreducible" interstitial-water saturation with permeability, is bound to be greatly reduced by measuring these properties on "adjacent" samples. For research purposes, amplification is scarcely required concerning the greater flexibility of a method for measuring porosity which leaves the core free of contamination by any liquid. Even under those circumstances which require that the core be saturated with a liquid, a previous measurement of porosity with a gas is useful in determining the degree of saturation that has been attained in the process. Furthermore, for comparable accuracy, porosity usually may be determined more rapidly with a gas than with a liquid. This advantage of the Boyle's-law instrument is most outstanding when the determination time is compared with that required in obtaining porosity by evacuation of the core followed by saturation with a liquid of known density. Several porosimeters which operate on the principle of Boyle's law have been described2,3,4,5,6,7 in the literature. No comparison will be attempted between those instruments and the ones described herein. Before helium gas became readily available, Boyle's-law porosimeters were subject to an appreciable error due to the adsorption of the operating gas on the surface of the core solids. There is considerable direct and indirect evidence in the literature to support the contention that the adsorption of helium on porous solids is negligible at room temperature. In discussing the use of Boyle's-law porosimeters, Washburn and Bunting2 stated that "for most ceramic bodies dry air is a satisfactory gas, but hydrogen will be required in some instances. Helium could, of course, be employed for all types of porous materials at room temperatures or above." Howard and Hulett8 obtained evidence that the adsorption of helium was negligible at room temperatures, even on activated carbon ; for the density measured with this gas was unaffected by changes in pressure or by changes in temperature from 25 °C to 75 °C. For oil-well cores, Taliaferro, Johnson, and Dewees" obtained lower porosities with helium than with air, but apparently did not study helium adsorption. From the work of these investigators, it follows that the use of helium in Boyle's-law porosimeters reduces the error due to gas adsorption to negligible proportions. This makes it possible to construct instruments which permit the determination of porosity with (1) a high degree of accuracy, (2) with great rapidity, and (3) without contamination. THE KOBE POROSIMETER The fundamental design of the Kobe Porosimeter was developed by Kobe, Inc., which firm built about 12 of the instruments during 1936 and 1937. Since that time, seven or eight more have been constructed with their permission, making a total of about 20 that have been put into operation.

Jan 1, 1950

By D. C. Hilty

C. E. SIMS*—This is a most interesting and important paper. It is important from two standpoints. First, it has as-spects of being highly accurate and therefore extremely useful to the operating man in showing how far he can go in oxidizing carbon from a steel bath while retaining chromium and the effect of temperature on this limit. Fig 5 is undoubtedly the highlight of the paper, and in checking it against available data, it seems capable of predicting actual results. The other important aspect is the apparently significant fact that reactions within a steel bath, such as between carbon and an oxide, are homogeneous reactions which do not require equilibrium with an external phase. In this case, it seems obvious that the reaction and the equilibrium established were between dissolved carbon (or carbide) and dissolved CrO. The classic reaction which requires equilibrium with solid Cr2O3, did not fit the data. It was recognition of this principle that made Fig 5 possible. G. R. FITTERER*—It might be in assuming the CrO is dissolved in the metal that you are actually approaching the correct factor for activity. If that is true and if the percentages that were used represent an equilibrium constant, this would mean, in effect, that the minimum temperature at which chromium would be reduced by an equivalent percentage of carbon would be about 2400°F from your equation. I believe that is in line with my experience particularly if you deal only with low percentages. J. CHIPMAN†—The author in discussing the equilibrium of the reaction offers two choices of explanation. One postulates an effect of chromium on the activity coefficient of carbon; it would require perhaps more data than are available to us at the present time to test this thoroughly. The other postulate which he offers is a reaction with CrO. This explanation is consistent with physical and chemical principles provided that a solid phase CrO is present, and that is essentially what he is postulating. If that oxide were present one would expect and, I think, almost require the kind of results that he obtained. The weakness of that postulate lies in the lack of confirmatory evidence regarding the presence of solid CrO as such. This should offer an interesting subject for further study. It seems a pity that the theoretical arguments revolving around CrO should have obscured for a moment the very real excellence of this paper. E. CARTER*—I think there is a problem that presents itself in practical application where the metal temperature is from 3200 to 3300 and the temperature desired in pouring is considerably less. B. M. LARSEN†—I get the impression from some of the work that was done earlier that there is probably a localized zone of high temperature at the slag metal interface which effects the removal of the carbon. Without that I wonder if the effect is possible to have a localized superheat and an equilibrium there favorable to low carbon content and

Jan 1, 1950

By G. Sachs, A. W. Dana, C. C. Chow

A great number of the investigations on the plastic flow of metals have been concerned with the establishment of a "universal" stress-strain relation. In such a relation some stress function when plotted against a strain function should yield identical curves for the various stress states. In the first investigation of this type, Ludwik and Scheu1 plotted the maximum shearing stress as a function of the maximum principal strain. Later Ros and Eichinger2 introduced two universal stress-strain relations, the one relating the maximum shearing stress to the maximum shearing strain, and the other relating a stress invariant, suggested by von Mises and Haigh, to the corresponding strain invariant. (In more recent investigations the stress and strain invariants are frequently supplemented with some factor to render their meaning more lucid.) A further suggestion which has not attracted appreciable attention is that by Baranski³ who used stress and strain deviators. The most common means of experimentation to determine the relation between stress and strain consists in subjecting thin walled tubes to combined internal pressure and axial tension.4a,4b,4c This method allows the study of plastic flow under stresses which are variable in two directions. However, the plastic flow which can be obtained in this manner is comparatively small, being limited by either tension failure or instability. For copper,'. only the relation between maximum shearing stress and maximum shearing strain yielded good agreement. On the other hand, tests on a stee14b and on an aluminum alloy4c. resulted in systematic deviations if any of the discussed universal stress-strain relations were used. It would seem, therefore, that the agreement mentioned above for copper is only incidental and explained by its high rate of strain hardening compared to that of other metals. Much larger strains than experienced in the tube tests can be obtained by subjecting a thin membrane of a ductile metal, which is restrained at its periphery, to a uniform hydraulic pressure. The thin sheet forms a deep bulge before it fails. The stresses and strains in such a bulge increase with increasing distance from the edge of the clamping "die," the maximum stresses and strains occurring at the pole (crown) of the bulge. While the stress and strain states are determined by the contour of the bulge, the absolute magnitude of the stresses and strains depends upon the hydraulic pressure. The bulge contour is in turn correlated with the geometry of the die opening. The deformation and fracture characteristics of circular bulges, that is, bulges formed with circular clamping dies, have been the subject of numerous experimental and analytical investi-gations.5,6,7 It has been shown that plastically deformed circular bulges develop large and comparatively uniform strains before failure by instability"6b,6c,6d and closely assume a spherical shape.6d Also the distribution of strains across the contour of the bulge is dependent on the metal being investigated and is correlated with, but cannot be predicted from, the metal's stress-strain characteristics. On the other hand, oblong or elliptical bulges, that is, bulges formed with elliptical clamping dies, are not as susceptible to analytical analysis and have not been investigated to the extent that circular bulges have. The few available data6c,7c indicate that stress states are obtained at the poles of the bulges, varying between plane strain and balanced biaxial tension, depending upon the geometry of the die opening. In this paper, the strain state and curvatures exhibited by three bulge shapes, a circular and two elliptical bulges, Fig 1, are analyzed experimentally using methods described in previous publications.6a,6c An attempt is made to derive the stress-strain relations for these bulges, which represent strain states in which the ratio of the two positive principal strains varied between 1.0 and 0.35. In addition, tension tests yielded data for a value of —0.5 for this strain ratio. Such an analysis should indicate the applicability of the various laws correlating stress with strain to the stress and strain states occurring in bulged shapes. Definitions and Nomenclature The definitions of the major stress and strain quantities used in this paper are as follows: s1, s2, s3 = principal normal stresses Sl > s2 > S3 t = shear stress e = conventional (unit) strain e = In (1 + e) El, E2, E3 = principal natural strains 7 = shear strain The maximum shear stress: , _ S1 — S3 lmax = 2 Frequently, the flow stress, s1 — s3 = 2lmax rather than the maximum shear stress is used.

Jan 1, 1950

By F. H. Wilson, M. L. Kronberg

The low temperature recrystalliza-tion of very heavily rolled copper produces a fine grained structure with a high degree of preferred orientation. Additional heating to within a few hundred degrees of the melting point may induce an abrupt and pronounced increase in the grain size, with the resulting crystals having new orientations. This behavior at high temperatures is commonly termed "secondary recrystallization." Several investigations have dealt with the phenomenon arid have served to bare many features of the beha~ior.1-4 In general,observations have been made on the sizes and shapes of the grains, and data have been presented showing the existence of an induction period in isothermal experiments. Although it has been well established that the orientation before the change is statistically (100) 10011, the so-called "cubically aligned" texture, there is no such agreement on the orientation after the change. For example, Dahl and Pawlek1 describe it as being equivalent to an approximately 30" rotation about the [l00] axis of the ideal cubic texture which is parallel to the rolling direction, the resulting orientation being near (210)[001]; and Cook and Richards2 find an orientation of approximately (110)[L12]. Since the completion of most of the work to be reported in this paper, Rowles and Boas3 have published their ver] illuminating paper on "secondary recrystallization," in which they present convincing evidence for a third orientation and show that their esperiments give no evidence for either of the other two orientations. The orientation is described as equivalent to an approximately 30° rotation about a [ 111] pole of the ideal cubic orientation. The existence of a variety of reported orientations is not unique for copper, for a similar state of affairs exists for other systems that have been studied— aluminum, nickel, nickel-iron alloys, and others. It seems therefore that the existence of this variety does not necessarily constitute a contradiction, but rather indicates that different experimental conditions yield different results. The fundamental nature of the phenomenon has not been elucidated. However, it has been generally recognized that the large grains could be the end product of growth of a few select grains already existing in the sample in minor amounts—too small to allow detection—or that entirely new ones could be formed by a process of nu-cleation and growth. Existing experimental evidence does not distinguish between these two most apparent possibilities. Nevertheless, the former has been more generally favored largely because our current understanding of the state of an annealed metal has not made it seem reasonable to expect a nucleation event to occur at temperatures above those required for the primary recrystallization. Observations on the Preparation and Heating of Twin-bearing Cubically Aligned Copper The starting material used throughout. the investigation was a bar of OFHC copper, forged and annealed at 950°C. Visual inspection showed the grain size to be around 0.5 mm, and did not disclose any preferred orientation. A chemical analysis showed the following composition: Cu + Ag— 99.99 Pct S — 0.005 pct 0 — <0.005 pct For the preparation of cubically aligned copper, ¾ in. thick slabs were cut from the bar, heavily pickled in concentrated HNO3 and cold rolled to sheets about 0.012 in. thick. The reduction in thickness was approximately 98.5 pct. Standardized annealing techniques were followed. Samples to be heated were lightly dusted with alumina in order to prevent sticking and then sandwiched between 1/16 in. copper plates. The resulting sandwich was heavily wrapped with copper sheet, and then annealed in air. The protection was such that only very thin films of oxide were formed. That the associated light oxidation of the samples had no specific effect on the recrystallization behavior was shown by the similar results that could be obtained on annealing in highly purified and dried hydrogen. Two methods were used in bringing samples to temperature: (1) by placing the package directly in the furnace at temperature and (2) by placing the package in the furnace at room temperature, and then slowly increasing the temperature. The corresponding heating rates are illustrated in Fig 1, and will be referred to as "rapid" and "slow," respectively. Unless specified otherwise, all anneals will be of the former type. Metallographic examination was made on samples prepared by electrolytic polishing and etching as described in the Metals Handhook.* STRUCTURES FOUND BEFORE "SECONDARY RECRYSTALLIZATION" OCCURS Annealing the rolled material for 1 hr at 400°C produced a heavily twinned, cubically aligned structure, the grain size being of the order of 0.03

Jan 1, 1950

By F. F. Poland

S. ROLLE*—As one who has been privileged to read Mr. Poland&apos;s paper before its publication, I wish to express high praise for it and the record which it gives of the work done by the Research and Development Department of Revere Copper and Brass Inc. in developing a satisfactory furnace for the recovery of metallic zinc from secondary metals by distillation. I have also had the opportunity of studying the operation of the furnace when running on scrap brass at the Detroit plant of Revere, and I can therefore say from knowledge gained first-hand that the unit is efficient and economical when used in conjunction with distillation. However, when I read what Mr. Poland has to say in reference to the possibility of using the furnace for melting copper cathodes for the production of oxygen-free and tough-pitch copper shapes, I am constrained to be somewhat skeptical. No doubt the furnace can readily be modified so as to make it possible to melt cathodes, but that is only a part of what is required to produce refinery shapes. Because of its construction the atmosphere in the furnace is highly reducing and even without protective gases such as nitrogen the copper cathodes which are

Jan 1, 1950

By V. E. McKelvey

The Phosphoria formation of the northwestern states presents a stimulating challenge to workers in every field of mineral technology. In addition to its large reserves of phosphate, the formation has been found to contain important amounts of fluorine and several metals, such as vanadium, nickel, and molybdenum. Because these minor metals in the Phosphoria do not have their usual glitter, concentrations of them are not easily discovered nor appraised. Like the phosphate itself, production of these metals very likely can be achieved only through use of costly chemical methods, for their mineralogy precludes treatment by the usual methods. In addition, in much of the area the containing rocks lie in complexly folded and faulted structures, which complicate mining and increase its cost. Yet the chain of research necessary to establish what elements are present; their geographic and stratigraphic distribution and reserves; the most suitable methods for recovering them; the combination of beds which, when ruined and processed, will yield the greatest recovery of the most valuable elements; and the methods most adaptable to their profitable extraction may well lead to the development of an important mineral industry and may make possible a significaut reduction in the cost of fertilizer this in itself would be an achievement of momentous importance—and at the same time make the nation more self-sustaining in critical materials. Although this research has great

Jan 1, 1950

By James F. Neill, O&apos

Investigation of the Gilley fluorite deposit was based upon examinations made by several of the Bureau&apos;s mining engineers. Fluorspar was found in the dump talus of sloughed and water-filled trenches and shafts, and there were indications that faulting or other dynamic distortions favorable to deposition of this mineral in minable quality and quantity might exist. The inference was based upon a field study of the area and its comparison with fluorspar deposits in Kentucky. The proximity of this deposit to the iron furnaces at Gadsden and Birmingham was a factor that influenced its investigation, as the demand for metallurgical grades of this critical mineral is acute. The present supply for the district is obtained from out-of-State sources, and the value of any local deposit would be enhanced by the saving in freight charges. The Gilley fluorspar deposit is 17 miles east of Gadsden and 50 miles northeast of Birmingham, Ala. Mineral deposits occur as thin veinlets and small bunches of fluorite in upturned bode of siliceous limestone. The ore-bearing structure is a reverse fold, and the mineral deposit appears as a replacement along crumbled zone fractures of the contorted limestone.

Jan 1, 1950