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By Thomas E. Wayland

AN isopachous map is one on which lines connect points of equal thickness of a given unit. This type of map is used by the Florida Phosphate Project of the U. S. Geological Survey to represent the economic phosphate deposits known as matrix and the waste material, or overburden, that overlies the matrix. The top of the bed on which the phosphate was deposited is known as the basement and a subsurface contour map of this old buried erosion surface is known as a basement map. Recent experiments have been made in preparing maps that show tonnages and grades of the phosphate content of the matrix. Few of the operating companies in the Florida phosphate district have applied isopachous (Greek isos, equal and pachys, thick) to mapping. The writer believes there is a need for the techniques discussed herein and that they can be applied to mapping other geologically similar areas in either economic or scientific investigations. The land-pebble phosphate district of Florida occupies a compact area in the west-central part of the state. It includes mainly the following land survey divisions: Ts. 27 S. through 32 S. and Rs. 20 E. through 26 E. The town of Mulberry, Fla., is in the approximate center of the district. The strata of the area, which is part of the Gulf Coastal Plain, occur in thin formations with broad outcrop belts, and low dips. The topography is subdued and gently rolling with three marine terraces, which are found at 30, 100, and 150 ft above sea level,' accounting for most of the relief. Occasional small sinkhole lakes are present, most of them above the 150-ft shoreline. The phosphate deposits occur in unconsolidated sediments such as clays, sands, and sandy clays. They are overlain by a heterogeneous assemblage of sands, clays, muck, and iron-cemented sand, easily penetrated, in most cases, by a hand auger or drill. Limestone, locally called bedrock, or a calcareous bedclay, thought to be a residue of the limestone, directly underlies the phosphate deposits. General Requirements Most companies and independent prospectors operating in the district have furnished prospecting data to the U. S. Geological Survey. The information is recorded on either field logs or prospecting maps and includes the following information for each hole drilled: location of the hole, thickness of the overburden, thickness of the matrix, phosphate content in long tons per acre, grade of the phosphate content expressed as the percentage of bone phosphate of lime (P2O5 x 2.18) or BPL, and the per- centages of iron-aluminum oxides and insolubles. The phosphate is classified according to size as either pebble or flotation material. The milling processes of the companies vary, and the size classification is necessarily different in many cases. However, pebble may be considered as larger than 14 mesh and flotation material as smaller than 14, but larger than 150 mesh. Some prospecting data include the exact depth at which bedrock or bedclay was reached, and these figures greatly increase the reliability of the data both for isopachous mapping and for mapping the basement. A drilling density of four holes per 40 acres of land furnishes a minimum amount of data for isopachous and related mapping. From the minimum of four, densities up to 32 holes per 40 acres are used. The various drilling densities may influence the choice of the proper scale. Selection of the proper scale is dependent upon the known drilling densities, the subsurface variations to be shown, the extent of the area to be mapped, and the detail desired in the completed map. Scales of 1:24,000, 1:4800, and 1:2400 are used in isopachous and related mapping by the Florida Phosphate Project. The 1:24,000 scale is used most effectively with drilling densities not exceeding eight holes per 40 acres. The subsurface variations should be relatively low and uniform, permitting the use of smaller intervals without undue crowding of the lines. Comparatively large areas can be mapped on this scale, but minute detail is necessarily sacrificed, because the information is drawn from a maximum drilling density of only eight holes per 40 acres. Isopachous and related maps of the 1:4800 scale are made of areas on which the drilling information covers from 4 to 16 holes per 40 acres. Moderate subsurface variations with relatively sharp gradations can be shown accurately. The area represented by the maps is reduced considerably in favor of detail. The 1:2400 scale is most frequently used by the Florida Phosphate Project. It lends itself particularly well to isopachous and related mapping, being easily adapted to the multiform drilling data available. Maps of this scale are prepared with information ranging from 4 to 32 holes per 40 acres; however, use of the minimum drilling density on the

Jan 1, 1952

By Robert Glass Cleland

[DATA OF THE YEAR 1950 COMPARED TO 1909 (FIRST CONSOLIDATED REPORT) CONSOLIDATED NET INCOME Without deduction for depletion of mines $ 42,395,465 $7,337,252 After deduction for depletion of mines $ 4,112,604 $7,337,252]

Jan 1, 1952

B. S. Crocker (Screened Ore Used for Fine Grinding at Lake Shore Mines, P. 499) was born in Toronto, Ont. and attended Saint Andrews College and University of Toronto. He received a B.A. and M.A. degree. He was graduated with honors and received a fellowship in metallurgy. Mr. Crocker did post-graduate research at University of Toronto from 1933 to 1934. He was employed by Beattie Gold Mines in 1933. He did research in milling at Lake Shore Mines from 1934 to 1936 and from 1936 to 1940 was head of experiment laboratory. At the present time he is mill superintendent with Lake Shore Mines at Kirkland Lake, Ont., Canada. Grinding, cyanidation, flotation and roasting are of special interest to him. He is a member of AIME. Mr. Crocker has presented several papers before C.I.M.M. and also holds membership in this society as well as Professional Engineers of Ontario. Skiing, yacht racing and photography are his favorite hobbies.

Jan 1, 1952

By Robert Glass Cleland

THE DEVELOPMENT of the Phelps Dodge copper and railroad interests began in one era of the company's history and continued unbroken into the next. Yet the two eras themselves were strikingly dissimilar and represented marked differences in the company's activities, corporate structure, and personnel. From its organization in 1834 almost to the end of the first decade of the twentieth century, the partnership known as Phelps Dodge was directed, managed, and controlled by the family dynasty established by Anson Greene Phelps. The last two directing partners of this three-generation-old regime assumed control of the company's affairs in 1879 when the economic revolution that followed the Civil War was well under way.' They lived in an age of gigantic undertakings, gigantic enterprises, gigantic combinations, gi- .

Jan 1, 1952

By S. R. B. Cooke, W. Philippoff, Donald E. Cadwell

[THE importance of contact angles in flotation has long been recognized, but little has been done to get quantitative relationships between the surface coverage of the mineral by the reagent, the length of the hydrocarbon chain, and the contact angle. It is well known that for a complete monolayer on the surface of a mineral the contact angle ? is determined only by the reagent&apos; and principally by the chain length of the hydrocarbon radical. Although for flotation the monolayer usually is regarded as being complete, early experiments of Wark and Cox2 showed that at very small concentrations of potassium ethyl xanthate the contact angle on galena changed in a continuous way from 0° to the equilibrium value of 60°. Further, Gaudin and Vincent&apos; showed a similar continuity using heptylic acid and sphalerite. This shows that with probably incomplete monolayers, ? varies with the degree of surface coverage. At the time these experiments were made it was impossible to measure the actual amount of surface coverage, especially since the decrease of the collector concentration in the liquor could be influenced by chemical side reactions. Through the use of the radioactive tracer method for the measurement of the amount of collector adsorbed on the surface of the mineral, Gaudin and Bloecher4 were able to determine accurately the actual surface coverage of dodecylamine acetate on quartz, but they did not measure any contact angles. It is believed that the relationship between the surface coverage and the contact angle is extremely important in flotation, especially as Gaudin and Bloecher showed that a 95 pct recovery is possible with a coverage of only 5 pct. Theoretical Considerations The work of adhesion W is the energy bound (in ergs per sq cm) when an interface is formed. It is determined by, the difference of the free surface energies (surface tensions) of the respective phases ?1 and ? 2 before contact and the interfacial free surface energy ?12 after contact. The definition of the contact angle permits the elimination of the unknown surface energy of the solid and hence the calculation5 of W from the surface tension of the liquid ? and the contact angle ?: [W = y (1 + cos ?)[1]] Consider a surface consisting of two components, identified as 2 and 3, 1 being the liquid. The amount of 2 in the composite surface is x, where 0 < x < 1. The respective contact angles with 1 and air are ? and ?3. The total work of adhesion of such a surface is the sum of the values of the components multiplied by their respective areas. A formal relation can be written: [W,,,=x•W2+ (1-x).WR[2] .] in which Wm is the work of adhesion of the composite surface. Eq 1 can be introduced into W2 and W3 but in the case of Wm some discussion is needed. If the two components are segregated, each component forming an integral part of the composite surface there is no physical meaning for a contact angle ?m, calculated from Wm, by using eq 1. If, on the other hand, the area of each patch of the components is small in comparison with, say, the diameter of the bubble used in measuring, it could be expected that ?m would have aphysical significance, because of the action of the surface tension of the liquid-gas interface tending to smooth out sharp corners. How small these patches would have to be is difficult to predict, but by using composite surfaces with microscopically]

Jan 1, 1952

By Joseph J. Becker

RECENTLY the "oriented growth" hypothesis of recrystallization textures has been receiving considerable attention. According to this view, "whenever a new generation of grains is growing in a highly oriented matrix . . . one may assume . . . that from among available nuclei of a great variety of orientations those with suitable orientation relationship with respect to the matrix have by far the highest rate of growth (oriented growth) and will, therefore, predominate."&apos; This statement includes primary recrystallization of single crystals and of polycrystalline materials showing strong deformation textures as particular cases. While the phenomenon of oriented growth undoubtedly does operate, and may be of importance in coarsening or secondary recrystallization, the writer feels that its extension to primary recrystallization is a different matter. Several aspects of this phenomenon may be pointed out which are difficult to rationalize on the basis of oriented growth. In recrystallizing deformed single crystals of alpha brass, Maddin, Mathewson, and Hibbard2 found that the twin composition planes of the recrystallized grains were parallel to the three operative slip planes they observed, and not to the fourth octahedral plane. The writer&apos;s current work seems to indicate further that when only one or two slip systems can be seen to operate, the recrystallized grains are aligned only with those slip planes actually observed. This behavior could hardly be accounted for by oriented growth, because on the latter basis the recrystallized texture of a deformed single crystal should certainly have the same symmetry as the crystal itself. Growth rates could not be expected to distinguish between crystallogra- phically equivalent directions, unless the presence of a visible slip system vastly increases the growth rate in the appropriate direction. This seems unlikely. These relationships were observed by the writer only when considerable care had been exercised before annealing to etch away the effects of cutting out the centers of tensile specimens with a jeweler&apos;s saw and to etch off the ends of compression specimens. When these.precautions were not taken, nu-cleation inevitably appeared to occur at the saw cuts or at the ends, and the resulting orientations never showed a [111] rotation but appeared quite random. The provision of many nuclei of many orientations did not enhance the correlation, but destroyed it. Recrystallization textures are sometimes strongly dependent on annealing temperature, which would imply that the anisotropy of growth rates is a suddenly varying function of temperature. This might be regarded as unlikely. Recrystallization textures can be strongly dependent on the degree of deformation. If textures are to be explained by selective growth from among nuclei of all orientations, it is difficult to see how the recrystallization process could have any dependence whatever on the manner or degree of deformation. It is felt that the above points should be considered before the oriented growth hypothesis is applied to primary recrystallization, with the necessary complete divorce of the mechanism of recrystallization from the details of the deformation process. References 1P. A. Beck and H. Hu: Reply to discussion of their paper on Recrystallization Texture and Coarsening Texture in High Purity Aluminum. Trans. AIME, 188, 1057; Journal oF Metals (Aug. 1950) TP 29083. &apos;R. Maddin, C. H. Mathewson, and W. R. Hibbard, Jr.: The Origin of Annealing Twins in Brass. Trans. AIME, 185, 655; Journal of Metals (Sept. 1949) TP 26763.

Jan 1, 1952

By R. Raring, W. J. Harris, J. A. Rinebolt

The effects of additions of alloying elements on the true-stress, true-strain characteristics of 0.30 pct C, 1.00 pct Mn, 0.30 pct Si pearlitic steel were studied. The alloying elements investigated were C, Mn, Si, P, The alloys are compared on the basis of fracture stress, fracture strain, energy to fracture, rate of strain hardening, strain hardening exponent, height of the flow curve, and lower yield point. IN the past, nearly all studies of the effects of alloying elements on the tensile properties of metals have compared the conventional engineering parameters, namely, tensile strength, yield strength, elongation, and reduction of area. Recently, however, the true-stress, true-strain method of recording results from the tension test has been used; Lacy and Gensamer,&apos; Hollomon," and French and Hibbard- are used this method to study the effects of composition on strength and ductility of metals. In this paper, the effects of certain alloying elements on true-stress, true-strain curves of steels with nearly constant grain size and pearlite spacing are presented. The notation employed in this paper is given in Table I. Since the definitions of stress and strain and the analytical geometry of the stress-strain curve have been explained previously, for example by Gensamer,&apos; they will not be reviewed here. However, the method used for the determination of energy to fracture, E,, requires mention. These energy values were calculated on the assumption that the flow curve followed the idealized equation:&apos; corresponds to the specific energy absorption to that strain value. There is justification for preferring the use of eq 1 for the determination of the energy to a particular strain rather than the area under the experimental stress-strain curve, since Gensamer showed that the use of the Bridgman correctione for stress at the neck of a tensile specimen brought the corrected experimental curve nearer to the idealized power-law curve than to the uncorrected experimental curve. However, it should be noted that the difference between the areas under the idealized curve and the experimental curve is not great for strain of less than 1.0, as can be seen from Fig. 1. In this figure, the true-stress, true-strain curve for a 0.01 pct C, 1.00 pct Mn steel is plotted through the experimental data points. From the value of a,, from this curve and the value of n as determined by the Inm-

Jan 1, 1952

By B. M. Larsen, T. E. Brower

A perspective is presented of the steel plant sulphur distribution and elimination problem from coal to liquid steel ready for teeming, giving distributions of sulphur over a range of coke sulphur content, and some methods of sulphur control, in the blast furnace, external desulphuriza-tion between blast furnace and open hearth, distribution between fuel, slag, and metal, and methods and limitations of control of sulphur in the open hearth furnace. AS a part of the 1951 AIME symposium on sulphur in steelmaking, it was thought that a discussion of the distribution of sulphur throughout the whole series of operations, from coal and ore to finished steel ingots, might have some value in giving a perspective on the whole problem. The following discussion is an attempt to present such an overall picture. The order is that of the actual plant operations, beginning with a very brief consideration of the coking process. Sulphur in Coal and Coke Since by far the largest source of sulphur entering the steelmaking cycle is in the coal used to make coke for the blast furnace, it would seem reasonable to eliminate some of it, either from the coal, or the coke, or during the coking process. This has appeared impracticable up to the present, at least, for two main reasons: the low activity of the organic sulphur in either coal or coke, and because of price limitations involved in treating a low cost material such as coke. A variable portion, usually M or less, of the sulphur is present in coal in the form of pyrites or similar compounds, and a large part of this sulphur may be removed in the coal washery. Most of the sulphur, however, is normally present as "organic" sulphur, intimately associated with the coal structure. Its distribution prevents any separation by mechanical means. Its low activity makes improbable &apos; any rapid chemical removal, although hydrogen will remove sulphur from both coal and coke. Thus, prolonged recirculation of coke oven gas in the coking process would tend to leave a smaller percentage of the total sulphur in the coke residue. Table I shows a typical distribution of sulphur from coal into products in the coking process. As the sulphur in the coal increases, the sulphur in the coke tends to increase in about the same proportion. Sulphur in the Blast Furnace The best picture of the situation in the blast furnace is provided by a sulphur balance of raw materials entering, and of products leaving, the furnace. The difficulties in accurate weighing and sampling of the variable solid materials entering this process, and the number of hours required for the raw materials to descend through the furnace under variable operating conditions, make it difficult to obtain an accurate balance. However, balances made over periods of weeks or months tend to average out some of these uncertainties. Table I1 presents three typical sulphur balances similar to a number that the writers have calculated. In most of these the slag volume calculated from the sulphur balance is, in some instances more, and in other instances less, than the value corresponding to the best input and output balances of the other slag constituents (lime, silica, alumina, etc.). Probably the greatest source of error in these calculations is the sulphur content of the slag. Despite some possible inaccuracies the balances of Table II show rather definitely the following points: 1—That 87 to 95 pct of the total sulphur input is in the coke and 95 to 97 pct of the total sulphur output is in the slag. Also, that if any sulphur leaves the furnace with the gas it is relatively small, amounting to a possible 1 pct or less. 2—At the lower sulphur coke level of 0.86 pct the total amount of sulphur charged is 15 Ib of sulphur per ton iron increasing to 26 lb per ton at the higher sulphur, intimately associated with the coal struc-rare burdens containing sulphur-rich ores will the total sulphur burden fail to be nearly proportional to the content in the coke used. 3—The 7 to 9 pct of the total sulphur input from the limestone of furnaces B and C is due to the relatively high sulphur content of the stone, 0.226 and 0.265 pct, respectively. In the case of furnace A, the sulphur content of the limestone was only 0.06 pct which resulted in only 3 pct of the total sulphur input coming from this source. It is rather interesting to compare the sulphur balances of a typical ferromanganese furnace with

Jan 1, 1952

Z. W. Bartlett, J. C. Carrington, H. C. Petersen and K. T. Price were elected vice-presidents of the Freeport Sulphur Co. Blandford C. Burgess was transferred on January 1 to the new Defense Materials Procurement Agency as strategic materials specialist. In May the Region III headquarters of this organization was moved to London. L. C. Campbell was elected president of National Coal Assn. Mr. Campbell, who has been a member of the National&apos;s Board of Directors and Executive Committee for many years, is vice-president of the Coal Div. of the Eastern Gas & Fuel Associates and in charge of their extensive mining operations in West Virginia, Pennsylvania and Kentucky. Vern H. Christoph has been transferred to Panama Canal Co., Marine Bureau, Navigation Division, Port Captains Office, as an admeasurer at Cristobal, Canal Zone. Eugene Cline, recently graduated from the University of Kentucky, has been employed by Pond Creek Pocahontas Coal Co., at Evanston, Ky. Sanford S. Cole, assistant manager of research at the Titanium div. of National Lead Co., received the Alumni Citation from his alma mater, Alfred University, Alfred, N. Y. This was in recognition of outstanding achievements and services in the field of ceramics which have brought honor to the institution. U. K. Custred, recently graduated from University of Kentucky, and may be reached now at Box 87, Monterey, Tenn. Robert E. Dwyer, executive vice-president of Anaconda since 1940, was recently elected president of this company and its subsidiaries, Chile Copper Co., Chile Exploration Co., and Andes Copper Mining Co. As president, Mr. Dwyer succeeds the late William H. Hoover who died in Butte, Mont.

Jan 1, 1952

By D. Turnbull, J. H. Hollomon

THERE is a large body of evidence&apos;" indicating that solidification during the liquid-solid transition is usually induced by heterogeneities present in the liquid. By dispersing liquid metals into small droplets, the impurities responsible for catalyzing solidification are isolated within a small number of these droplets. The effect of the foreign body therefore is restricted to a single drop by this technique. Thus upon cooling below the melting temperature, solidification is initiated by homogeneous nucleation in the majority of the droplets that do not contain impurities. In the case of solidification of liquid metals, the activation energy for nucleation is so great that its rate changes by orders of magnitude for a change in temperature of only several degrees centigrade.&apos; Effectively homogeneous nucleation occurs at a critical temperature upon continuous cooling. Thus by microscopic observation of single particles during cooling, a temperature at which the rate of homogeneous nucleation becomes sensible can be determined.3 since at the temperatures at which nucleation occurs in the absence of impurities the rate of crystal growth is extremely rapid, the temperature at which the entire particle solidifies is very nearly the temperature at which the nucleation of the solidification occurs. Thus for liquids that freeze at high temperatures the onset of nucleation can be established by simply observing the temperature at which the marked heat evolution and increase in brightness of the particle occur. For liquids that freeze at lower temperatures the onset of nucleation can be determined by a rumpling and change in shape of the particle resulting from its solidification. The microscopic technique for observing the solidification of small particles has already been described." In earlier papers the nucleation of solidification of pure metals 5,6 and of alloy systems7 showing complete liquid and solid solubility have been described. In the present paper, the observations are extended to a simple eutectic system (Pb-Sn) where the possibility of the formation of two solid phases exists. Metals for the investigation were obtained from the American Smelting and Refining Co. in the form of pure lead and pure tin, 99.8 and 99.9 pct purity, respectively. An ingot of each of the pure metals was made into shot by heating the metals at a temperature about 50 °C in excess of the melting point and pouring the liquid slowly into a container of water at 15°C. Samples of the shotted pure metals were weighed out to make alloys containing 5, 10, 15, 20, 25, 30, 40, 50, 60, 70, 80, and 90 atomic pct Pb. Samples of each alloy were then melted in separate beakers. Each melt was poured through a pyrex funnel into a cylindrical mold (% in. ID). The casting solidified in 10 to 20 sec. The inside of the mold as well as the funnel through which the metal was poured were coated with graphite to eliminate adherence of the metal. Analyses were performed on some of the compositions and are given in Table I. The compositions also were checked for these samples and for those that were not analyzed by determining the spread between the liquidus and the solidus upon melting the small metal particles. These measurements agreed as well with the nominal compositions as the analyses listed above. Results The results of the supercooling experiments for the several alloys are summarized in Table II and plotted on the constitution diagram in Fig. 1. Data for the pure lead and pure tin were taken from earlier investigations. The values for the maximum supercooling of the several alloys are the average of several determinations on a number of drops of each alloy. The maximum value in any determination was within about 2 pct of the average. For the alloys containing from 20 to 60 atomic pct Sn, inclusive, two marked changes of the surface structure were observed upon cooling. At the higher temperature, after the first appearance of the solid phase it continued to grow slowly at a constant temperature and then stopped. At the lower temperature the alteration of surface structure was abrupt. For the alloys containing from 70 to 95 atomic pct Sn, inclusive, an abrupt change in surface structure was observed at a single critical temperature.

Jan 1, 1952

Jan 1, 1952

By R. C. Amero

FULLERS earth is a general name applied to claylike minerals that have high natural ad-sorptive powers. They are usually distinguished from ordinary clays by a higher content of combined moisture and a lower apparent density. The definition is based on the ancient use of the material for fulling, or cleansing woolen cloth of oil and grease; a more modern definition should mention the ability to decolorize oil and should differentiate between fullers earth, which is naturally active, and certain bentonites which only develop decolorizing power after being leached with strong mineral acids. The distinction between fullers earth and activable bentonite is not a sharp one, since all types of intermediate clays can be found that are more or less naturally active, yet more or less responsive to acid treatment. The differences seem to depend somewhat on the amount of leaching that has been effected by natural ground waters. Physical Properties The principal mineral constituent of activable bentonite is montmorillonite, a hydrous aluminum silicate to which the following formula is generally assigned: Al,Si,O,, (OH), • 12H,O Fullers earth, as well as bentonite, is usually composed of some variety of montmorillonite, but in the United States the largest tonnage of fullers earth is mined from deposits of attapulgite. Attapul- gite is a clay mineral composed of monoclinic crystals of colloidal size, having a fibrous shape similar to that of asbestos. A sectional model of the attapulgite "molecule" is shown in Fig. 1. A single unit is about 18.0 A wide and 12.9 A high. The length of the molecule is variable, but this same molecular pattern is repeated to form needlework crystals, rather than flakes, as is characteristic of the montmorillonite crystals. Attapulgite has been assigned the following formula,&apos; although actually, the magnesia has been largely replaced by alumina: (0%) . (OH), • Mg, . Si, • Olp . 4H20. The fibrous nature of the mineral is clearly shown in the electron micrograph, Fig. 2. Although the deposits contain 5 to 30 pct quartz and carbonate minerals, impurities in the commercial products are held at a low level, principally by selective mining on the basis of oil decolorizing efficiency. The particle size distribution of this fullers earth has been estimated from settling rates, using sodium citrate as a dispersing agent.&apos; Since Stokes&apos; law only applies to spherical particles, the equivalent particle diameter calculated below is probably more nearly an index of diameter rather than length of the needlelike crystals: Eqnivalent Arbitrary Particle Distribution, Size Diameter Pci Classil3catian 0.05 mm 0.80 0.80 pct sand 0.05-0.02 mm 10.96 0.02-0.01 mm 9.65 42.10 pct silt 0.01-0.005 mm 11.40 0.005-0.002 mm 10.09 2-0.5 micron 10.61 0.5-0.2 micron 29.09 56.58 pct clay 0.2-0.05 micron 14.86 0.05 micron 1.96 The differential thermal analysis shown in Fig. 3 is unique and supports the theory that this is a distinct mineral species.&apos; ~ Other general properties of the mineral as shown in Table I.

Jan 1, 1952

Frank L. Bader has been appointed to the sales staff of Lehigh Navigation Coal Co. in the Philadelphia territory. H. C. Burrell, former coordinator of raw materials, Pittsburgh, Penna., has been made manager of raw materials for Columbia-Geneva Div. of U. S. Steel Co., San Francisco. J. H. Cazier has resigned as general superintendent of Bagdad Copper Corp., Bagdad, Ariz., to devote full time with E. A. Scholz to the operation of the Copper King, Phillips and Black Pearl Mines near Bagdad. They have operated the Copper King zinc mine for more than two years.. Production started from the Black Pearl and Phillips tungsten mines during the past year. Robert T. Chapman has resigned from Reynolds Mining Corp. to join Westmoreland Manganese Corp. as general superintendent. Annan Cook, with Kennecott Copper Corp.&apos;s exploration dept. for the past three years, has been appointed district geologist for the eastern states.

Jan 1, 1952

By J. E. Walstrom

While intensive research continues to promote a more complete understanding of the potential and resistivity measurements that comprise the electric log, it is believed that consideration should also be given to translating these numerous and often widely separated findings into a coordinated and readable body of fundamental facts designed specifically for the petroleum engineer and geologist. Although provision is made through publication for a ready exchange of new theoretical concepts. it is also desirable to provide reviews and appraisals of the more established techniques and methods from the operating standpoint so that an economic and practical application may be realized concurrently with the theoretical progress. With these basic premises as a guide the author reviews the presnt state of electric log interpretation. The paper is directed not so much to the logging or research specialist as to the petroleum engineer and geologist to whom the electric log is only one of the many tools which he employs. Frequently, these persons do not have the time to follow in detail the many specialized contributions that appear and, as a consequence. are not in a position to place these contributions in proper relation to each other, or to the art as a whole. The paper reviews the basic steps in making quantitative determinations from the electric log of the amount of oil or gas present in subsurface formations and also discusses the degree of reliability of these determinations under various conditions. The paper also indicates the trend of future developments in electric logging systems and methods of interpretation. INTRODUCTION The electric log has been used about 20 years as a means for studying the formations penetrated by a well bore. The first half of this period is characterized by the development of suitable logging techniques and equipment. Although progress in this direction is continuing at a satisfactory rate, the last ten years are characterized more by an increasing interest in methods of electric log interpretation. During this period, a large number of fundamental papers have been published, expounding various logging techniques and particular phases of the interpretation problem. Many of these papers represent important contributions, and a few are classic. This paper is an effort to outline as concisely as possible and in simple terms the main course of progress in electric log interpretation. More specifically, it is the purpose of the paper to review the necessary elements and basic steps used in making quantitative determinations of water saturation from the electric log; and to point out the degree of reliability of these determinations under different conditions. It is strongly advised that the operating staffs of the drilling and exploration departments of oil companies cooperate wholeheartedly with both the electric logging service companies and research organizations in the testing and development of new logging systems and interpretation methods. One purpose of the paper is. however, to indicate the degree of caution which must be exercised in placing confidence in new techniques and interpretation methods that have not been thoroughly tested in the field. It is entirely possible to be cooperative in trying new methods and yet reluctant to believe in the results until the methods are firmly established. It is important to define the meaning of quantitative electric log interpretation. In the most general sense, an interpretation of the log has been made when the electrical characteristics of the formations, as portrayed on the log, have been translated into terms describing the formation geometry, rock type, or any other physical characteristics of the formations. The determination that the top of a sand is at a certain depth is an interpretation of the log. Structural determinations made by correlating electric logs from a given area are also interpretations of the logs. The term quantitative interpretation, however, will be used in this paper in the restricted sense to indicate the determination of the water saturation of a formation. This determination defines the fluid content of an oil and gas productive formation only if the porosity is known, and it assumes that the remainder of the pore space contains hydrocarbons. This assumption is believed to be true for most oil and gas productive formations. The quantitative electric log interpretation may he said to be a determination of the fluid content only to the extent which the water saturation, under the conditions given above. defines it. THE BASIC STEPS The fundamental steps in calculating water saturation from the electric log are: 1. Determination of the true resistivity of the formations from the apparent resistivities as recorded on the electric log.

Jan 1, 1952

By C. R. Fast

In order to evaluate the ability of a Hydrafrac treatment to effect a sustained increase in well production, data were accumulated on the first 65 wells in 26 fields treated by Stano-lind. Since these data were obtained from such a large number of fields, it is felt that individual well or reservoir characteristics do not affect the overall picture, as might be the case if the study were made in one field or one group of wells in a field. These data are tabulated in Table I and plotted on Figs. 1 and 2. An analysis of Fig. 1 shows that at the end of six months, 75 per cent, or 45, of 60 wells on which data were available showed a sustained production increase. At the end of two years, data were available on 25 wells. Of these, 15 wells, or 60 per cent, showed a sustained production increase. At the end of three years, 55 per cent, or 10, of 18 wells had a production rate greater at that time than before Hydrafrac treatment. The lack of information on additional wells at the end of the third year is primarily a result of the small number of treatments conducted in the early stages of field application

Jan 1, 1952

By E. F. Reed

CONSIDERABLE deep hole prospect drilling has been done in the last few years in the Globe-Miami mining district about 70 miles east of Phoenix, Arizona, and in the San Manuel-Tiger area about 50 miles south of the Globe-Miami region. More than 205,000 ft of churn drilling have been completed by the San Manuel Copper Corp. at their property in the Old Hat Mining District in southern Pinal County. The deepest hole on this property is 2850 ft; there are 49 holes deeper than 2000 ft. At the adjoining Houghton property of the Anaconda Copper Mining Co., where only one hole reached 2000-ft depth, there were 27,472 ft of churn drilling and 3436 ft of diamond drilling. Three churn drill holes were deepened by diamond drilling methods. Near Miami in the Globe-Miami district the Amico Mining Corp. drilled four holes by combined churn and rotary drilling methods, the total amounting to 13,879 ft, of which 2256 ft were drilled with a portable rotary rig. In the same district, besides doing a large amount of shallow prospect drilling, the Miami Copper Co. drilled two holes of 2560 and 3787 ft, respectively, which were completed by churn drilling methods. The rocks encountered in drilling at San Manuel and Tiger are described by Steele and Rubly in their paper on the San Manuel Prospect&apos; and by Chapman in a report on the San Manuel Copper Deposit? The rocks are well-consolidated Gila conglomerate, quartz , monzonite, and monzonite porphyry. In some places these formations stand very well while being drilled, and three holes were drilled without casing, the deepest of which was 2200 ft. In other holes faulted and fractured ground made drilling difficult. In the Globe-Miami district the deep drilling was done in the down-faulted block of Gila conglomerate east of the Miami fault and in the underlying Pinal schist. The geology of this area is described by Ransome.3 In the Amico holes the conglomerate varied from material consisting entirely of granite boulders and fragments to a rock made up of schist fragments in a sandy matrix; in the Miami Copper Co. holes there were more granite boulders and the material was poorly consolidated. Drilling was much more difficult and expensive in the Miami area than in the San Manuel district, mainly because of the depth of the holes and the formations drilled. All the deep hole prospecting described in this paper was done with portable rigs. The churn drill rigs were of several types, of which the Bucyrus-Erie were the most popular. Bucyrus-Erie 28L, 29W, and 36L rigs were used on some of the deeper holes on the San Manuel property. A few Fort Worth spudder types were tried, and the deepest hole at San Manuel was drilled with a Fort Worth Jumbo H. The spudder type is considerably larger than most other rigs used on this work and required a larger location site. The spudders were belt-driven machines with separate power units, and time required for setting up and moving was much longer than with the more portable drills. All the churn drilling was done by contractors or with machinery leased from them. A few of the contractors had complete equipment, including most of the necessary fishing tools. Unusual and special, fishing tools were obtainable from the supply companies in the oil fields of New Mexico or in the Los Angeles area. Most of the contractors used equipment with standard API tool joints, so that much of it was interchangeable. Failure of tool joints is one of the principal causes of fishing jobs. It can be minimized if the joints are kept to the API specifications and the proper sized joints are used in the various holes. The minimum sizes that should be used with various bits are as follows: 12-in. and larger bits, 4x5-in. tool joints; 10-in. bits, 3 1/4x4 1/4-in. tool joints; 8-in. bits, 2 3/4x 3 3/4-in. tool joints; 6-in. bits, 2 1/4 x3 l/4 -in. tool joints; 4-in. bits, 1 5/8 x2 5/8-in. tool joints. Two rotary drill rigs were tried at San Manuel on the same hole, and a portable rotary drill rig was used on the Amico drilling for test coring the formation and for drilling in holes 3 and 4. Rotary drilling differs from churn drilling or cable tool drilling in that the bit is revolved by a string of drill pipe and the cuttings are removed from the hole by a thin solution of mud pumped through the drill pipe. The principal parts of a rotary rig are the power unit, a rotating table to revolve the drill pipe, hoists to raise and lower the pipe and to handle casing, and a pumping system to circulate the drilling liquid. The rig used on the Amico property at Miami was mounted on a truck. The larger rig used on the San Manuel property was hauled by several trucks and had separate turntable and pumping units. Diamond drill coring equipment was used successfully with the rotary rig in the holes on the Amico property, To allow for 2 3/8-in. drill pipe with tool joints, 3 1/2-in. core barrels and bits were used. With the standard 3 1/2-in. core barrel there was considerable difficulty in maintaining circulation with mud, so a barrel was designed with a smaller inner tube and a broad-faced bit. This allowed coarser material to circulate between the barrels. Rock bits of 5 5/8 to 3 7/8 in. were used with the rotary rig for drilling between core runs. Diamond drill equipment is much lighter than churn drill tools, so that fishing tools can usually be obtained from supply houses by air express when needed. Three churn drill holes on the Houghton property at Tiger were deepened by diamond drilling with Longyear UG Straitline gasoline-driven-machines. The open churn drill hole was cased with 2 1/2-in. black pipe. In deep hole churn drilling, casing is one of the most important items, especially in drilling in unconsolidated material like the formations drilled by

Jan 1, 1952

Jan 1, 1952

By R. U. Jackson

FACED with rising costs, the mining industry is looking to new methods and equipment to supply the relief necessary for profitable operation. Conveyor transportation is rapidly taking a superior position to motor tramming in underground mines because of lower installation, maintenance, and operating costs. Haulage is always a critical problem in underground mining. The ease of operation and flexibility of a haulage system can have an important effect on ultimate mining cost. With the average tenor of ores on the downgrade, larger tonnages are required for the same metal recovery. This selection of a tramming system can be the key to a successful, paying plant. Because this shift is being made at an ever advancing rate, it may become necessary to tailor mining operations to the transportation system, rather than to select a haulage system fitting set mining methods. In choosing a haulage system, the relative costs of the various methods are of the greatest importance. Adapting the mine to one or the other type of tramming is not considered in the cost analysis, and very likely would make little difference, outside of location of drifts and raises. In the cost sheet, the problem presents recommendations for a conveyor installation and a comparison of equipment, installation, operation, maintenance, and power costs are made. Under the track haulage estimate, no allowance was made for dumping equipment at the shaft pocket or bin. If this equipment was added to the balance sheet, the additional

Jan 1, 1952

By E. E. Donath

THE coal hydrogenation process is well known as a means for the production of liquid fuels -from coal. In this paper the possibilities of the coal hydrogenation process as a source of chemical raw materials will be discussed. The recovery of chemicals from coal hydrogenation products necessitates some modifications and additions to the equipment used for the production of fuels. The conversion of coal into liquid fuels such as gasoline requires two steps: liquid phase and vapor phase hydrogenation. Intermediate oils obtained in the liquid phase contain oxygen and nitrogen compounds, especially aromatic compounds, since the coal itself is composed mainly of cyclic compounds. These oils are the raw material for the separation of high molecular weight aromatics and of tar acids and tar bases. The relative amounts of heavy and middle oil-boiling above and below, e.g., 325°C-can be influenced by temperature, residence time, and catalyst of the liquid phase hydrogenation. In the vapor phase hydrogenation a solid bed catalyst is used to convert the intermediate oil from the liquid phase operation into hydrocarbons of the gasoline boiling range. Essentially pure hydrocarbons with a low content of sulphur, oxygen, nitrogen, and olefines are obtained. Depending mainly on the catalyst, the high ring compound content of the liquid phase oil can be preserved and gasoline rich in aromatics obtained. However, with other catalysts, these ring compounds can be split into gasoline with a high content of isoparaffins.1 Again, depending on the operating conditions, products of varying boiling range can be obtained. Selection of catalyst and operating conditions therefore makes possible the production of different grades of motor fuel and also variations in the relative amounts of benzene, toluene, and xylene when aromatic hydrocarbons are produced. The schematic flowsheet, Fig. 1, shows the main steps of the coal hydrogenation process, and the product streams used for the recovery of chemicals are indicated. In the liquid phase hydrogenation stage, coal is made into a paste with recycle heavy oil. The coal paste is mixed with hydrogen and preheated at a pressure of 300 to 700 atm in heat exchangers and preheaters. The coal paste and hydro¬gen enter high pressure converters where the liquefaction of coal, conversion of the high boiling liquid materials initially obtained, into intermediate oils is performed at a temperature around 470°C. The reaction products enter the hot catchpot in which lower boiling oil vapors are separated from the residue containing unreacted coal, ash, and heavy oil. This residue, usually called H.O.L.D. (heavy oil let down), is processed to separate solid and liquid material. By thermal treatment of the residue, e.g., a coking process, distillate oil is obtained, which can be recycled as part of the pasting oil. This stream is rich in polynuclear aromatics and can be, and has been, used for the recovery of such material. The oil vapors and hydrogen from the hot catch-pot are cooled in heat exchangers and a cooler, and the condensed oil is separated from the recycle hy-

Jan 1, 1952

By Richard H. Jahns

GRANITIC pegmatite deposits are the chief source of commercial feldspar, sheet mica, beryllium, tantalum-columbium, and lithium minerals, and certain types of kaolin. They also have yielded significant quantities of cassiterite, gems, scrap mica, molybdenite, tungsten minerals, uranium-thorium and rare-earth minerals, and zircon, either directly or as the sources of placer deposits. The output from pegmatite mines in the United States is small as compared to other mineral products in terms of bulk or value, and much of it comprises minor metals and nonmetals. Nevertheless, pegmatite minerals play a vital part in domestic industrial economy, particularly in the ceramic and electrical industries. Numerous special purpose uses also are important, even though they require small quantities of raw materials. Never was United States dependence upon pegmatite mining more clearly emphasized than during World War 11, when greatly expanded demands and uncertainties of foreign sources of supply caused much concern. Such commodities as beryl, tantalite, and sheet muscovite remained high on the critical list for months at a time, and for some minerals there was a real struggle to achieve and maintain a favorable ratio of supply to demand. Satisfactory stock piles of certain sizes and qualities of sheet mica, for example, were not built up until late in 1944, when wartime requirements already had begun to level off or even to decrease. Production of all the strategic pegmatite minerals from domestic deposits during World War I1 constituted only 10 pct or less of the total domestic consumption of these minerals, but the importance of this contribution should not be minimized. Domestic production often represented the difference between increase and further reduction of existing stocks of commodities already in seriously short supply, and in the early stages of the war it was the only assured source if imports were cut off. During the recent war period, the U. S. Geological Survey carried on a program of pegmatite studies in the New England and Southeastern States, in the Black Hills area of South Dakota, in the Rocky Mountain region of Wyoming, Colorado, and New Mexico, and in various parts of Washington, Idaho, Utah, Nevada, Arizona, and California as shown in Fig. 1. Several papers and reports already have appeared as an outgrowth of this work,&apos;-= and others are in preparation. This paper outlines some results of data obtained by the writer during the period 1942 to 1946, when he was engaged in studies of pegmatites in the Southeastern, Southwestern, and Rocky Mountain States. Beryllium Minerals Beryl is the present commercial source of beryllium metal and beryllium compounds, which are used in ceramics, in the preparation of X-ray tubes and fluorescent lamps and screens, in special processes of paint and textile manufacture, and in the optical systems of some electrical instruments. The metal also is used in nuclear physics, chiefly as a source of neutrons. Beryllium is alloyed with aluminum for certain light-metal uses and is a constituent of some nickel and iron alloys. Currently the chief demand, however, is for copper-base alloys, which are exceptionally resistant to fatigue and wear, are responsive to hardening treatments after

Jan 1, 1952