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By Rodolfo V. de la Cruz

The in situ deformability of rock masses is determined by relating the applied load to the radial displacements of points on the borehole wall that are outside of the loaded surfaces. The external displacement method includes the steps in which: a) radial displacement sensors are installed to measure the change in length of a diameter of a borehole; b) unidirectional self- equilibrating pair of forces perpendicular to the direction of radial displacement measurements are applied on opposite sectors of the borehole wall, and; c) using elastic theory, the in-situ deformability of the rock mass can be related with the applied loads and measured radial displacements. The displacements outside the loaded surfaces are comparatively smaller in magnitude than displacements inside the loaded surfaces. These displacements, however, are sufficiently large and can be measured precisely by commercially available linear displacement sensors. Loads are applied by a conventional borehole jack. Existing methods for measuring the in situ deformability of rock masses yields unreliable results due to complex boundary stresses, small and varying contact areas, and the existence of fractures. It was shown that in the external displacement method, the effect of boundary pressure distribution and contact area are negligible. Also, since the displacements measured in the external displacement method were due to materials that are deeper inside the rock mass, borehole fractures have less influence on the calculated deformation modulus.

Jan 1, 1982

By F. L. Bosqui

INTRODUCTION The history of the development of gold metallurgy in South Africa is divisible into two periods: That preceding the introduction of the cyanide process on a commercial scale in 1890; and the 24 years intervening between that important event and the present time. The period between the discovery of the banket reefs of the Witwatersrand and the year 1890 was one of phenomenally rapid progress in mining development, but of no special interest to the metallurgist. There were no strikingly original or distinctly local advances in the treatment of gold ores. Californian practice in stamp milling and amalgamation prevailed, in mills ranging in equipment between 5 and 50 stamps, operating within a wide range of efficiency, and under the trying conditions usually en¬countered in a new and isolated field. The somewhat incomplete records of gold output of that period show that in December, 1887, there were 20 producing companies in the Witwatersrand district, of which 10 had mills, the largest being of 20 stamps. The only official record of returns for May, 1887, was that of the Wemmer mine, whose modest achievement with a 5-stamp, mill was 100 tons crushed, producing 887 oz. 3 dwt. of gold. This is interesting in view of the .present-day output of this field, which in 1913 reached 8,430,998 oz. The rapid increase of production during this first period (May, 1887, to January, 1891) is shown by the following summary for the year 1890:1 Total tons crushed 702,828 Number of stamps in operation 1,046 Average number of tons crushed per stamp per day 2.36 Yield of gold, ounces 494,817 Yield per ton, pennyweights 13.36 The stamp duty ranged between 1 ½ and 4 tons per day, according to weight of stamp, fineness of screen, and operating skill available. The prevailing weight of stamp was about 900 lb., and the screen, 900 meshes to the square inch.

Jan 5, 1915

By Alfred Weiss

Daniel C. Jackling's innovative concept for handling low grade ores ushered in a new philosophy of open pit mining. As one of the greatest minemakers of all times he revolutionized major segments of the industry and helped strengthen US defense efforts during World Wars I and II by making possible the tremendous copper supplies from US mines. Many great mining men have since followed in his footsteps with their discoveries of new orebodies or development of new mines. Their brilliance in leadership can also be traced to the coupling of a new idea to the physical nature of the materials in the earth's crust or to the extractive stages of minerals recovery. The minerals industry is now in another era of change and must again devise techniques to meet the challenge. The task is not only to create new exploration techniques and develop new mining methods, but, I believe, to optimally apply new concepts and tools in daily decision-making.

Jan 11, 1978

By P. R. Bradley

This paper gives a brief history of the mining and milling operations in the Juneau gold belt, and a general description of the geology of the district, followed by a suggestive discussion of the general problem of sampling gold ores and a detailed description of the mining methods used in the Alaska Juneau mine. The paper indicates that variations in assaying ore similar to that from the gold belt are unavoidable on account of the erratic distribution of the gold. A caving system that accepts dilution was adopted for the Alaska Juneau mine; the ore is sorted and the final mill feed has nearly twice the assay value of the ore trammed. THE property of the Alaska Juneau Gold Mining Co., covering the Juneau gold belt for over a mile in length, consists of 136 claims and 24 mill sites; these are near Juneau, Alaska, in what is known as the Harris mining district.

Jan 3, 1924

By C. D. Locker

COMMON salt is mentioned in the most ancient writings as an impor-tant article of diet. It is fairly certain that it was used by men and animals long before the dawn of civilization. Its presence in natural springs has often been the determining factor in colonization; wars have been fought for possession of salt deposits; trade routes have been estab-lished expressly for the purpose of traffic in salt. Naturally this led men into adventures and discoveries that altered history and advanced civilization. In the early days the uses for salt were few and the methods of manu-facture were crude and the purity low when compared to salt of the pres-ent day. Then the salt came largely from springs, shallow wells or the ocean, while today deep wells must be drilled to the natural brines or beds of rock -salt and spacious shafts sunk so that the ancient deposits may be made to yield their supply of stored mineral.

Jan 1, 1936

By D. C. Shelton

This paper discusses the metallurgical testing procedures and their applications at the laboratories and mills of Pima Mining Co. The author shows, using discussions and case histories, that routine sampling and evaluation of daily and monthly data can be as valuable as thorough laboratory investigations and mill test work. A great deal of valuable information can be made available this way. This paper discusses laboratory and mill metal-lurgical testing procedures and their applications at Pima Mining Co., located about 25 miles southwest of Tuscon, Ariz. The Company, incorporated in 1951 (the year the orebody was found) in California to operate the Pima mine, is jointly owned by Cyprus Mines Corp., Utah Contruction and Mining Co., and Union Oil Co. Milling started in December 1956. The main Pima orebody is a contact metamorphic vein of copper-bearing hornfels with an average dip of 45° to the south with an east-west strike. The hanging and footwalls are quartzitic pyroclastics (arkosite) containing some sulfides. Barren igneous intrusions are also present. Conglomerates and alluvial wash cover the deposit to a depth averaging about 200 ft. The principal copper mineral is chal-copyrite. Native copper, chalcocite, and minor amounts of chrysocolla and other copper minerals are also present, together with sphalerite and some molybdenite. Generally, it has been noted that the ratio of chalcocite to chalcopyrite is higher in the lower grade ores, while as the grade increases, there are only minor amounts of chalcocite. Open pit mining is employed at Pima, using both trucks and an inclined skiphoist system. A detailed description of Pima Mining Co. operations was presented by Spaulding et all. More recently another orebody to the north and east of the present pit has been discovered and will be placed in operation within a few years. This ore is of a porphyritic rather than a lode nature since values are disseminated in both igneous and metamor- phosed sedimentary rocks. The new orebody is expected to be harder and cleaner than the present deposit. The views expressed in this article are those of the author and do not necessarily reflect those of Pima Mining Co. nor of the profession in general. PlMA MILL The following outline of milling practice is presented to furnish a background for later chapters of this report wherein specific problems will be detailed and analyzed. Run of mine ore is crushed in three stages, using conventional equipment to 85% minus 1/2-in. for feed to two 10 x l6-ft rod mills operating in open circuit. Each rod mill discharge is split between two 10% x 13-ft ball mills in closed circuit with three 20-in. cyclones. In addition, a 7 x 12-ft ball mill with one 20-in. cyclone receives part of the discharge from one of the rod mills. This equipment was manufactured by Allis Chalmers and Equipment Engineers. The cyclone overflows are combined, sampled and, after joining the regrind cyclone overflow, are distributed into 12 10-cell Fagergren 66-in. flotation machines. The primary rougher concentrate produced

Jan 1, 1965

By Oscar Weiss

STILFONTEIN and surrounding areas gave nega-tive results in all prospecting attempts since about 1904 when Goerz and Co., a forerunner of Union Corporation Ltd., first drilled in the region and on the farm Stilfontein. Subsequent efforts by African and European Investments Co. and Anglo American Corp. from 1934-37 were completely unsuccessful. Holes drilled by these companies on the farms Riet-fontein, Hessie, and Palmietfontein were stopped in the Lower Witwatersrand system without finding payable reefs. The results of gravimeter, ground magnetometer, and aerial magnetometer surveys are presented in the area, in and around the new Stilfontein Gold Mine, in the Klerksdorp District of the Transvaal in the Union of South Africa. The gravimeter and ground magnetic surveys were completed in 1947—48. The gravity anomalies suggested a block of Upper Witwatersrand quartzites faulted-up between denser rocks of dolomite and Ventersdorp lava. Boreholes S.T. 1, 2, and 3 were drilled in 1948 and, after penetrating the dolomite and Ventersdorp lava, entered Upper Witwatersrand quartzites and intersected the Gold Estates Reef and Vaal Reef. Subsequent drilling delineated the suboutcrop of the Vaal Reef and determined the main structure of this horizon. The gold content of the Vaal Reef was highly payable and shaft sinking is now in progress. The Stilfontein Gold Mining Co. has been formed and, up to date, f5,000,000 capital has been raised for plant, shaft sinking, and development. The payable Vaal Reef horizon extends further south from Stilfontein, the reef occurring at increasing depths. It is possible that at least another mine may be established on these deeper horizons. The farm Stilfontein 39 is situated in the Klerksdorp District of the Transvaal. This farm and the surrounding areas have been subjected to repeated programs of prospecting dating back to about 1904, when Goerz and Co., the forerunner of Union Corporation, Ltd., first drilled on the farm and in the surrounding areas. From 1934-37, numerous boreholes were drilled on the neighboring farms, Riet-fontein. Hessie. and Palmietfontein, by African and European Investment Co. and Anglo American Corp. All these efforts were completely unsuccessful, and nobody suspected any possible gold-bearing area on Stilfontein until about 1947, when a gravity traverse run by B. D. Maree on the main road, showed a negative gravity anomaly. During 1947-48, the writer's organization completed gravimeter and magnetic surveys on Stilfontein and Rieffontein. An area of negative gravity anomalies was mapped, and it was suggested that this could be caused by blocks of Upper Witwatersrand quartzites, of the average density of 2.65, faulted up between dolomites and Ventersdorp lavas, the density of both of these rocks being 2.8. Fig. 1 shows the geology of the area as mapped by L. T. Nel of the Geological Survey of South Africa. The boreholes on Stilfontein, with the exception of a single hole of Goerz and Co., were drilled after the completion of the geophysical survey. The grouping of the first boreholes S.T. 1, 2, 3, 4, 5, and 6, clearly shows that these were located in the zone of negative gravity anomalies. Fig. 2 shows the gravity anomaly contours. Fig. 3 shows two sections across the gravity anomaly, together with the corresponding geological sections as obtained from boreholes. The close relation between gravity values and thickness of dolomite plus Ventersdorp lavas is striking. The two latter formations having the same density (2.8), act as one mass as far as gravity effects are concerned. Fig. 4 shows the magnetic anomalies observed on the ground by vertical magnetometers and at 500 ft abbve mean ground level by aerial magnetometer. The latter are anomalies of the total magnetic intensity. The magnetic results show that, on the farm Rietfontein and on the northern half of Stilfontein. Lower Witwatersrand magnetic shales were to be expected at relatively shallow depths. As the strongly

Jan 1, 1952

By L. G. Truby

This paper presents the results obtained after calculating matches of the observed pressure performance of five fields completed in a common aquifer. A general dejcription of the Central Basin Platform area in West Texas in which the five fields, Andector, Embear, Martin, TXL, and wheeler, are lo. cated is contained in the paper. The method of utilizing the electric analyzer to calculate simultaneously matches of the observed pressure performance of the five fields is outlined. The determination of boundaries of pressure communication is discussed and the extent of pressure interference between fields consistent with the configuration of the area aquifer is shown graphically. INTRODUCTION Anomalies in the pressure performance of the Andeector Ellenhurger Field resulted in an investigation of pressure interference between several Ellenburger fields located on the Central Basin Platform in West Texas. Four fields, Embar, Martin, TXL, and Wheeler, were found to contribute significantly to the pressure drawdown at Andector. An initial investigation of the pressure performance of the Andector Ellenburger Field revealed that the reservoir pressure could not be matched by the calculation technique usually applied to water drive reservoirs. In the past, many have advanced the opinion that fracturing in the Ellenburger was a local condition restricted to the immediate uplifted area around the field, in which case each field would in all probability be surrounded by its own relatively small aquifer. Following several unsuccessful attempts to account for the pressure performance at Andector, a system assuming a common aquifer involving several fields in the immediate vicinity of Andector was placed on the electric analyzer and the effect of lo. interference was noted. A refinement of the initial analyzer calculations involved the determination of the approximate boundaries of the aquifer, the calculation of detailed matches of the pressure performance of the interfering fields, and an evaluation of the degree of communication between fields. DISCUSSION Geology and Development The fields considered in this work are located in the Central Basin Platform, a north-south trending structural feature in West Texas lying between the Delaware Basin to the west and the Midland Basin to the east. The locations of various individual Ellenburger fields in this general are shown in Fig. 1 with the five major fields which appear to be definitely intercommunicating colored in black and located in the circled portion of the figure. Production from the five fields was first obtained from the Embar Field discovered in July 1942, followed by the Wheeler Field in 1943, the TXL Field in 1945, and the Martin and Andector Fields in 1946. The total reservoir fluid production from these fields is indicated in Fig. 2. As illllstrated in this figure, very little production was taken from these fields prior

Jan 1, 1952

By P. W. Bakarian

Previous determinationl,2,3 of the texture of magnesium and its alloys have shown only slight variations in the principal features of the structure. This investigation presents pole figures for magnesium and two of its alloys, in which differences of some magnitude will be shown. Schmid and Wassermann have considered the texture of magnesium in analogy with that of zinc—also a hexagonal lattice. Whereas the zinc texture is said to be derived primarily through basal slip and secondarily through {IO2}† twinning, the {102} twinning is considered impossible at the later stages of the rolling in magnesium because of its smaller axial ratio. This state of affairs appears reasonable for pure magnesium, but for alloy textures the situation is more complex. A double orientation similar to that found in zinc has been reported by J. D. Hanawalt,4 and the addition of small amounts of calcium to magnesium and its alloys to produce a double texture was noted by J. C. McDonald.5 The pole figures of this investigation, using an improved X-ray technique, show these various textures. The dependence of directional properties of rolled sheet on modifications of texture is well recognized. Correlation of physical properties with existing texture should be even more significant if quantitative valuations are attached to the various areas on the pole figures. Such a quantitative technique is developed herein. Experimental Method Two alloys were used, besides high-purity magnesium. In each case, the metal was extruded to bars 1/2 in. thick and hot-rolled to a thickness of about 0.075 in. It had been established previously that such a reduction was more than sufficient to eliminate the extruded structure. The rolling proceeded in the same direction as that of the extrusion, without any cross rolling. The temperatures corresponded to normal commercial practice, averaging around 600°F. A unique method of preparing the sample was developed in this work. Instead of using a flat specimen, a stem of the metal was cut out of the rolled sheet in the desired direction (rolling direction) as shown in Fig. I. From a sheet of 0.075 to 0.065-in. gauge, the stem was cut to a square cross section with a jeweler's saw, rounded with a file and polishing paper to a diameter of 0.060 in. and evenly etched in dilute hydrochloric acid to a diameter of 0.038 + 0.001 in. In this way, a cylinder of the original sheet with its axis in the desired direction was produced. By using this type of specimen for the pin-point pictures, any variance in the absorption of the diffracted beam at the various angular settings of the specimen, was completely eliminated.*

Jan 1, 1942

By P. W. Bakarian

Previous determinationl,2,3 of the texture of magnesium and its alloys have shown only slight variations in the principal features of the structure. This investigation presents pole figures for magnesium and two of its alloys, in which differences of some magnitude will be shown. Schmid and Wassermann have considered the texture of magnesium in analogy with that of zinc—also a hexagonal lattice. Whereas the zinc texture is said to be derived primarily through basal slip and secondarily through {IO2}† twinning, the {102} twinning is considered impossible at the later stages of the rolling in magnesium because of its smaller axial ratio. This state of affairs appears reasonable for pure magnesium, but for alloy textures the situation is more complex. A double orientation similar to that found in zinc has been reported by J. D. Hanawalt,4 and the addition of small amounts of calcium to magnesium and its alloys to produce a double texture was noted by J. C. McDonald.5 The pole figures of this investigation, using an improved X-ray technique, show these various textures. The dependence of directional properties of rolled sheet on modifications of texture is well recognized. Correlation of physical properties with existing texture should be even more significant if quantitative valuations are attached to the various areas on the pole figures. Such a quantitative technique is developed herein. Experimental Method Two alloys were used, besides high-purity magnesium. In each case, the metal was extruded to bars 1/2 in. thick and hot-rolled to a thickness of about 0.075 in. It had been established previously that such a reduction was more than sufficient to eliminate the extruded structure. The rolling proceeded in the same direction as that of the extrusion, without any cross rolling. The temperatures corresponded to normal commercial practice, averaging around 600°F. A unique method of preparing the sample was developed in this work. Instead of using a flat specimen, a stem of the metal was cut out of the rolled sheet in the desired direction (rolling direction) as shown in Fig. I. From a sheet of 0.075 to 0.065-in. gauge, the stem was cut to a square cross section with a jeweler's saw, rounded with a file and polishing paper to a diameter of 0.060 in. and evenly etched in dilute hydrochloric acid to a diameter of 0.038 + 0.001 in. In this way, a cylinder of the original sheet with its axis in the desired direction was produced. By using this type of specimen for the pin-point pictures, any variance in the absorption of the diffracted beam at the various angular settings of the specimen, was completely eliminated.*

Jan 1, 1942

By John V. Beall

Thai means free. Historically accurate, as the country has never been subjugated by foreign occupation, the name "The Land of the Free" also seems to fit the attitude of the people. At the Bangkok airport, without so much as a kopkhun (thank you), travelers are found behind, beside and in front of ticket counters. A pretty Thai face on TV calls flights in English and Thai. Baggage disappears with alarming rapidity and your reporter and spouse despaired of ever being reunited with it. But at the entrance, all the parts came together and there was even a limousine from our hotel, The Oriental. Driving downtown English style, we noted that there were four lanes of traffic occupying the space we would allow for three lanes. Motorcycles and enclosed three-wheel motorcycle taxis were much in evidence, but the occasional water buffalo held up the slow lane. In the city, men wore European-type slacks and shirts but the women were colorful in traditional ankle-length wraparound skirts.

Jan 1, 1970

I TOLD you before that four things are necessary in addition to good judgment for one who wishes to practice the art of casting well. The first is to make the moulds and to have the furnace well made, the wood of a good kind, dry and seasoned, and the material disposed to melt. I have given you enlightenment on all these in detail, and on the last point as well, as you can see in the discussion on the alloys of metals where, among other things, I told you a good deal about those of copper. Therefore I wish to say but little about them in this chapter, but in order to follow the order promised you, I tell you that when you can, and if the labor or expense does not displease you, you should always alloy the whole quantity of the metals that you wish to put into one work and should make them into cakes of one kind. For, in addition to being more conveniently arranged in the furnace and mire easily handled, they all melt at one time and with much less work than they would if they were in pieces of different kinds. It is necessary to give corruption to copper, for if you decided to melt fine copper by itself in a reverberatory furnace your soul would burst before you had any honor therefrom. Then, if you wished to cast a fine thing from it, it would not succeed because it is dot fluid, on account of its viscosity; and if it should succeed, it would be all full of holes, like a

Jan 1, 1942

By A. J. McEvily, R. C. Boettner, C. Laird

The processes leading to fatigue failure in the low-cycle range were studied to obtain an understanding of the basis of Coffin's law. Particular attention was paid to the manner of mack nucleation and to the determination of the portion of the total lifetime spent in crack propagation. It was observed that cracks are nucleated at surface notches meated during reversed plastic deformation, Principally at grain boundaries, and that crack growth occupies greater than 75 pct of the fatigue life. When inclusions are present, they are often the primary sites of crack initiation. From consideration of the incremental distances advanced by a crack in each cycle and of the lifetimes of different materials, it appears that the universality of Coffin's law arises from the similarity of crack-tip strain for a given applied strain amplitude, irrespecti7:e of material. STUDIES of low-cycle fatigue have been particularly rewarding in that a simple correlation between fatigue lifetime and plastic-strain range has been shown to exist. This empirical relationship takes the forml,2 Nner=C [1] where N is the number of cycles to failure, Er is the plastic-strain range defined as the total plastic strain per cycle (the sum of the tensile plastic strain plus the compressive plastic strain), n, the exponent, is a constant independent of the material to a first-order approximation and often has a value of about 0.5, and C is a constant which for a number of ductile and metallurgically stable materials is approximately 0.65 for fully reversed strain.3 This relationship has been shown to be valid for a wide variety of metals and alloys and is often referred to as Coffin's law. However, it is yet not clear why so many different metals and alloys exhibit the same over-all behavior in the low-cycle range. Less is known about the mechanisms of fatigue failure in the low-cycle range than in the high-cycle range, but it is expected that the processes would have much in common. For example, an important characteristic common to both high-and low-cycle ranges is that fatigue crack propagation can occupy a considerable portion of the total lifetime. This has been shown by Laird and smith4 by a count of the number of ripples present on the fracture surface of copper specimens, each ripple corresponding to one cycle of load. On the other hand, some marked differences have been noted. For example, in copper,5 nickel, and aluminum4 there is a greater tendency for grain boundary cracking to occur as the strain amplitude is increased. The purpose of the present work was to study further the processes leading to fatigue failure in the low-cycle range and to obtain an understanding of the basis for the validity of Coffin's law. Particular attention has been paid to the manner of crack initiation and to the determination of the portion of total lifetime spent in crack propagation. MATERIALS A number of metals and alloys were tested, although more attention was focused on a particular few, once general trends had become apparent. Alloys were selected so as to investigate the effects of crystal structure, number of phases, stacking-fault energy, and impurity content. The materials in this grouping were: high-purity copper OFHC copper 1100 aluminum (commercially pure) 70-30 brass (Cu-30 wt pct Zn)

Jan 1, 1965

By F. R. Van Horn

WALLACE MCKEEHAN, Douglas, Ariz. (communication to the Secretary*).-In going over this report, which I have done very carefully, I find that the summary as composed deals with the various problems almost entirely from the employer's standpoint and that practically no consideration is given to the employee's point of view. An experience of 3 ½ years as safety inspector, and almost 30 years as workman-and official, has convinced me that any plan for the betterment of working conditions which will achieve any degree of success must give the workmen their share of responsibility and allow them full participation. The company may finance and direct the movement, but its ultimate success depends upon the support given by the workmen. The cooperation of the men doing the actual work is so essential that all writers insist that this must be secured, but they do not agree as to how this can best be done.

Jan 4, 1917

By John T. Galey

In all, 210 wellst were completed in southwestern Pennsylvania during 1939, which is 59 more than were drilled during the preceding year. Of this number, 137 were gas wells, which is a considerable increase from the 81 completed during 1938. Only 25 oil wells were completed, as against 28 in the previous year, and 28 dry holes, 6 more than last year. Shallow Development—Gas The increase in the number of gas wells is largely the result of a search for additional gas in Armstrong and Indiana Counties. Although a considerable number of wells were drilled in the latter county, the majority of them produced less than 100 M cu. ft. initial open flow. In Armstrong County, a new pool was opened in Cowanshannock township, producing from the third Bradford sand. Several large wells were obtained there, one of which produced an initial of nearly 12 million cu. ft., with a reservoir pressure of 1100 Ib. However, the productive area has been fairly well outlined by further drilling and shows that the pool covers only about 800 acres. The sand is 20 to 30 ft. thick, and probably has 5 to 6 ft. of pay. Thus this reserve is not an important one. Several wells were found in Menallen township, Fayette County, where the Big Injun sand has been having a play for the past three years, but the activity there is much less than a year ago. Oil On the west side of the Bradford sand gas pool, Cowanshannock township, Armstrong County, a well was drilled which flowed 100 bbl. the first day from the Tiona sand. The probability is that this well is a freak, as the Tiona has been drilled within a fairly close distance on every

Jan 1, 1940

By John T. Galey

In all, 210 wellst were completed in southwestern Pennsylvania during 1939, which is 59 more than were drilled during the preceding year. Of this number, 137 were gas wells, which is a considerable increase from the 81 completed during 1938. Only 25 oil wells were completed, as against 28 in the previous year, and 28 dry holes, 6 more than last year. Shallow Development—Gas The increase in the number of gas wells is largely the result of a search for additional gas in Armstrong and Indiana Counties. Although a considerable number of wells were drilled in the latter county, the majority of them produced less than 100 M cu. ft. initial open flow. In Armstrong County, a new pool was opened in Cowanshannock township, producing from the third Bradford sand. Several large wells were obtained there, one of which produced an initial of nearly 12 million cu. ft., with a reservoir pressure of 1100 Ib. However, the productive area has been fairly well outlined by further drilling and shows that the pool covers only about 800 acres. The sand is 20 to 30 ft. thick, and probably has 5 to 6 ft. of pay. Thus this reserve is not an important one. Several wells were found in Menallen township, Fayette County, where the Big Injun sand has been having a play for the past three years, but the activity there is much less than a year ago. Oil On the west side of the Bradford sand gas pool, Cowanshannock township, Armstrong County, a well was drilled which flowed 100 bbl. the first day from the Tiona sand. The probability is that this well is a freak, as the Tiona has been drilled within a fairly close distance on every

Jan 1, 1940

By B. J. Guarnera

There have been major changes in the makeup and nature of the uranium exploration industry in recent years. Significant price increases precipitated an increase in exploration activity-according to the Department of Energy, exploratory drilling in 1977, by 140 companies, was almost 8 million m (26 million ft). This represents a 37% increase over the prior year's drilling. Projections for 1978 indicate at least 9 million m (30 million ft) of exploratory holes will be drilled in the US. Exploration expenditures in 1979, including land acquisition, drilling, and other costs, were estimated by DOE at over $236 million. Domestic expenditures for 1978 are estimated at over $250 million.

Jan 10, 1978

By S. R. B. Cooke, C. E. Thurston, G. Kudo

The trend toward utilization of low grade iron ores means that more efficient methods must be developed for their concentration. The collecting ability of fatty acids derived from fish oils has been extensively investigated by Cooke.' Tuna oil, a byproduct of the tuna canning industry, is one of the lower priced fish oils. Utilization of tuna oil fatty acids as collectors in the flotation of iron ore might be economically feasible under certain market conditions, especially if their efficiency were high. Crude or unfractionated tuna oil fatty acids, and five fractions derived therefrom, were tested for their ability to concentrate a commercial specularite ore from northern Michigan. A commercial fatty acid derived from tall oil, and commonly used in nonsulfide flotation, was used as a reference. The crude fatty acids were obtained by simple saponification of tuna oil. Fractions A and B were obtained by acetone precipitation of the crude acids at -5O and -2S°C, respectively. Fraction C was obtained by a partial fractional distillation at 12S°C and at a pressure of 3y in a centrifugal molecular still in order to remove the shortest and longest chain fatty acids of tuna oil as well as oxidation products present in the original mixture. Fractions D and E were prepared by a chilling process in order to precipitate the unwanted saturated fatty acids. Yields and iodine values of the materials used are listed below: The seven samples were used as collectors in a laboratory procedure patterned after the commercial process for flotation of Michigan specularite ore. The outline of the procedure is that previously described1

Jan 1, 1962

By Hans-Jürgen Schaller, Horst A. Brodowsky

Activity coefficients of boron in palladium were determined at concentrations up to PdB0.23 by reducing B2O3 between 870" and 1050°C in a controlled H2-H2stream and measuring the resulting weight gain. The deviations from ideal behavior closely resemble those of the system Pd-H and are interpreted in terms of three principles: 1) The solute atoms occupy octahedral interstitial positions. 2) They donate their valence electrons to the 4 d and 5s bands of palladium, raising its Fermi energy. 3) The lattice strain energy is lower for two nearesl -neighbor interstitial particles than for two farther separate ones. SOLID solutions of hydrogen in palladium are a useful subject for studying thermodynamic aspects of the formation of alloys and of nonstoichiometric systems.1-3 The activity of hydrogen is readily measurable to a high degree of accuracy,4'5 even at low temperatures where the deviations from ideal behavior are more pronounced, and its simple structure facilitates an interpretation of these deviations in terms of a detailed model. Two effects are discussed to account for the non-ideal properties:3 An "electronic" effect, connected with the rise of the Fermi energy, as electrons of the interstitial hydrogen atoms enter the electron gas of the metal, and an "elastic" effect, due to an interaction of the regions of strain around each interstitial atom. The electronic effect is based on the idea that the lowest energy levels of the dissolved hydrogen atoms are higher than the Fermi energy, so that the electron will not occupy a localized state but enter into the electron band of the metal.6 The elastic effect is based on the observation that dissolved hydrogen distorts and expands the palladium lattice. The hypothesis is put forward that the elastic strain energy is lower for two adjacent dilatational centers than for two separate ones; i.e., they attract each other. The resulting pair interaction can be used to calculate an elastic contribution to the thermodynamic excess functions by means of one of the statistical methods. This model permitted a detailed description of the solution properties of hydrogen in palladium3 and in palladium alloys.798 An extension of the approach to describe the excess functions of substitutional palladium alloys is possible.9 In order to further test and refine the model, an investigation of other interstitial alloys was started. Palladium dissolves considerable amounts of boron in homogeneous solid solution.10 The palladium lattice expands linearly up to nB = 0.23 (nB = B/Pd atomic ratio), the highest concentration studied." The expan- sion, extrapolated for 1 mole of interstitial per mole of palladium, is 17 pct of the lattice constant of pure palladium vs 5.7 pct in the case of hydrogen.12 The fact that the lattice expands rather than contracts is a strong indication that interstitial positions are occupied. According to neutron diffraction experiments, hydrogen occupies the octahedral sites of the fcc lattice.13 Unfortunately, this direct evidence is not available for the Pb-B system, mainly because of the high-reaction cross section of boron with thermal neutrons. However, by way of analogy and on the grounds of the rather close similarities between the two systems to be reported here, it seems safe to attribute octahedral positions to the dissolved boron, too. At higher boron contents, compounds of stoichiomet-ric compositions are reported such as Pd3B, which has the structure of cementite,14 so that a close structural relationship seems to exist with the system r Fe-C. In their study of hydrogen absorption in Pb-B alloys, Sieverts and Briining noted that alloys with an atomic ratio of about nB = 0.16 are no longer homogeneous15 This observation was confirmed in an extensive X-ray investigation.11,16 The phase boundaries of two miscibility gaps were established. One two-phase region was stable below a transition temperature of about 315°C and extended from nB = 0.015 to 0.178. The other one extended from nB = 0.021 to 0.114 slightly above the transition temperature and had an apex at nB = 0.065 and 410°C. All phases involved have the fcc structure of pure palladium with lattice expansions proportional to their boron contents. The occurrence of miscibility gaps, i.e., the coexistence of dilute and concentrated phases, points to an energy of attraction between the dissolved particles, in the Pb-B system as well as in the Pd-H system. The filling up of the electron bands seems to be analogous, too, in the two systems, as indicated by the hydrogen absorption capacit15,17,18 and by the suscepti bility of Pd-B alloys.l8 In both types of experiments, boron acts as an electron donor. A chemical method was used to measure the activity of boron in palladium. Boron trioxide was reduced in a moist hydrogen stream: B2O3 + 3H2 = 2B + 3H3O [l] At known activities or partial pressures of boron trioxide, hydrogen, and water, the activity of boron could be calculated from the law of mass action. The equilibrium concentration of boron corresponding to this activity was determined as the weight gain of the sample. EXPERIMENTAL The samples consisted of small pieces of foil of 0.1 mm thickness and about 100 mg weight. The palladium was supplied by DEGUSSA, Germany, and stated to be

Jan 1, 1970

By P. H. Royster

For a number of years the Bureau of Mines has been investigating certain problems relating to the blast furnace. In the course of these investigations it was desirable to measure, with the optical pyrometer, the temperatures occurring in the hearth of the furnace. Since no systematic measurements of these temperatures have been published a statement of the results may be of interest. The data given in this paper were obtained it thirty-two blast furnaces operated by seventeen companies; twenty of these furnaces were making iron, eight ferromanganese, and five spiegeleisen. The collection of this information was made possible by the cooperation of the American Manganese Co., Bethlehem Steel Corpn., Brier Hill Steel Co., Buffalo Union Furnace Co., Clinton Iron & Steel Co., Donner Steel Co., John B. Guernsey & Co., Jones & Laughlin Steel Co., E. E. Marshall, the McKinney Steel Co., National Tube Co., New Jersey Zinc Co., Republic Iron & Steel Co., Seaboard Steel & Manganese Corpn., Southeastern Iron Corpn., the Youngstown Sheet & Tube Co., and the Wharton Steel Co.

Jan 9, 1919