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By R. Woods

INTRODUCTION Gaudin (1), considered that "the mechanism of mineral collection is the central problem of flotation theory". From their work on adsorption phenomena in flotation for more than fifty years (2), Gaudin and his co-workers have made major contributions to the elucidation of this mechanism, a fact acknowledged by their contemporaries in the field (e.g. (3)). Their investigations in a number of areas, e. g. demonstrating that submonolayer quantities of adsorbed collector species can induce flotation, or identifying the influence of substances which can activate or depress (1), have helped to provide the basis for and the development of a theory to account for the interaction between mineral and collector. It was established in the late fifties (4) that the presence of oxygen is a prerequisite for the flotation of metal sulfides with thiol collectors. This fact rendered inadequate the concept of simple ion adsorption being responsible for rendering these minerals hydrophobic. The requirement for oxygen has been explained (1) in terms of this species being a component in chemical reactions between the sulfide surface and the collector. Gaudin has been instrumental in identifying the products of chemical reactions at sulfide minerals (1, 5), a line of work which has been continued particularly by Finkelstein and co-workers in South Africa (6). In presenting a detailed mechanism of the mineral-collector- oxygen interaction, it has often been considered that the mineral surface [must] first be oxidized to a metal oxy-sulfur species which

Jan 1, 1976

By AIME AIME

THE No. 9 mine of the Wheeling & Lake Erie Coal Mining Co., a subsidiary of M. A. Hanna & Co., at Fairpoint, Ohio, has normally produced about 1000 tons of coal daily for several years, but recently it was converted into an experimental mine to afford means of studying new methods and equipment under consideration for development and mining. Among other projects, the possibility of using a duck-bill, self- loading conveyor in driving entries, with a view of in- creasing the rate of progress where quick development is of importance was studied. Actual operation soon revealed that even though break-throughs are made ,every 60 ft., as required by the state mining laws, the :amount of natural Ventilation reaching the working face was not sufficient to supply the men and that in ,order to obtain a plentiful supply of pure. air and maximum efficiency and to avoid costly interruptions after shots, it was necessary to supply auxiliary ventilation by using Ventube and a Vano fan.

Jan 1, 1929

By Charles Bell

THE Telluride mining district of southwestern Colorado is defined by the 37° 45' and 38° parallels of latitude and 107° 45' and 108° meridians of longitude. Telluride was never a boom camp, but has had a steady growth. In recent years, notwithstanding the business depression of 1920, the business has been the same as in normal years. The first prospector is said to have appeared in 1875, in which year locations on the Smuggler vein were made. Shipments were made in 1877 and 1878, and in 1879 milling the ores was attempted. While the district produced high-grade ores, it did not become important until 1890, when the Rio Grande Southern R. R. was completed from Ridgway to Telluride. The railroad has since been extended to Durango. In the fall of 1896, 400 stamps were in operation, and the annual production was $3,000,000.00, two-thirds of which was gold. The total production from 1875 to 1923 was: Gold $58,274,527; silver 41,830,920 oz., valued at $31,016,893; copper 15,258,866 lb., valued at $2,533,291; lead 166,056,484 lb., valued at $8,324,910; zinc 18,141,182 lb. valued at $1,323,787; or a total production of $101,473,408. All: claims are held in fee. Most of them are 1500 by 300 ft. but claims located within the last few years are 1500 by 600 ft. General supplies are obtained at Telluride, Denver, and Salt Lake. The largest mines are within 6 miles of the town of Telluride. Denver is 422 miles and Salt Lake is 439 miles, by rail, from Telluride. One-half of the distance to Denver and one-sixth of the distance from Telluride to Salt Lake is by narrow-gage railroad. The labor is efficient. The best miners are Italians and Austrians, then Slavs, Greeks, and Mexicans follow in the order mentioned. There are no labor unions. There are no serious mine pumping problems, the drainage being through adits. The Tomboy and Smuggler companies pump water from their reservoirs, the former for, milling and domestic purposes and the latter for milling, power, and domestic purposes.

Jan 2, 1924

By M. E. Straumanis, J. -P. Krumme

In basic ([KOH + KCl] with a total polarity of 2) or acidic (2N H2SO4) electrolytes and at anodic current densities of more thun 2 to 4 ma per sq cnz, n-type GaAs single crystals of lozo resistivity preferentially dissol~je forming etch tunnels with triangular or civc~ilay cross sections and of a width between 0.5 arid 5 p. These etch tunnels are oriented along any one of the four possible (111) directions of GaAs. However, their growth occurs only in one direction of a given (111) whick apparently is determined by the atomic sequence Ga —As (and not the rezlerse) in respect to an individual valence bridge in the crystal. It is concluded from comparison with the cubic lattice structure of GaAs that the etch tunnels represent macroscopic evidence for the tetrahedral bonds and their polar properties. If the anodic current density is increased the tunnel fomation results in the development of a fibrous surface layer consisting of GaAs. The latter separates frorn the substrate (in an anodic s~irface disintegration process) by the growth pressure of an As,0, filnz forming in the interior of the fibrous layer, 100 to 200 µ under the surface, at more than about 50 ma per sq cni. The fibrous GaAs film has the same crystallographic orientation as the substvate and represents a skeleton of the original crystal. Since the etch-tunnel density in a separated GaAs layer is about 108 c?n-', and the etch tunnels develop only along (111) in a given polar direction, it is assurraed tlmt the dislocations have no influence on the growth of these tunnels. ElECTROLYTIC treatment of smooth surfaces of poly- and single-crystalline GaAs at high anodic current densities causes the formation of porous surface layers.' This phenomenon suggests comparison with effects being observed with magnesium,' indium,, gallium,4 and aluminum5 and known as "anodic disintegration". The purpose of the present paper is to explore and to explain the reasons for the formation of such surface layers on GaAs and, in particular, to investigate the influence of the lattice polarity of this III-V compound semiconductor in the (111) direction on the anodic dissolution behavior. GaAs SINGLE CRYSTALS For the experiments described below GaAs single crystals from the Monsanto Co., St. Louis, Mo., were used. Their impurity levels were below 1 ppm and their dopant levels between 1 and 100 ppm. They were grown in (111) using the Czochralski or the gradient-freeze technique. The crystals had n-type conductivity and electric resistivities between 1 and 5 ohm-cm. EXPERIMENTAL The GaAs single-crystal rods were cut perpendicularly to (111) into wafers of about 1 mm thickness using a wire-blade crystal slicer and an aqueous slurry of Sic or a diamond saw. The orientation of the faces of these wafers were checked by Laue back-reflection patterns. If there was a deviation from (111) the faces were abraded under a certain angle using grinding paper and distilled water. The damaged surface layer was removed from each crystal by chemical etching with a mixture of 1HF:1HNO3: 1H20 or 2HF:1HNO3:2HAc (glacial). {110) faces were obtained by mechanical cleavage, producing surfaces which did not require a further treatment. The GaAs wafers were mounted using "alligator" clamps instead of soldered electrical contacts.' Only the bare crystal surfaces were dipped into the electrolyte. The clamps were coated with insulating wax to prevent any contact with the electrolyte. The experiments were carried out in aqueous 2 N H2so4,' or in an aqueous solution of KOH and KCl1 (1 mole KOH + 1 mole KCl in 1000 cu cm solution). Anodic current densities up to several hundred ma per sq cm were applied for periods between 30 sec and 2 hr. For the purpose of investigating the initial steps of disintegration the anodic current density applied never exceeded 20 ma per sq cm. The films which partially separated from the anodic surfaces under high-field conditions were treated with KOH to further their detachment by dissolving the As2O3 formed. The washed and dried films were pasted to strips of filter paper, and Laue pictures were made. The back-reflection patterns obtained were compared with those of the original anode surface before and after anodic dissolution. Furthermore, space reciprocal lattices7 were constructed from asymmetric rotation crystal patternsa which permitted the determination of the crystallographic orientation of the detached films of the corrugated anodic surfaces. The disintegration products were identified from assymmetric powder patterns.8 The polarity of the {111) faces was determined by chemical etching with mixtures of 1HF:1H2O2(30 pct): 2H2O or 1HNO3:2H2O. Different patterns on each of two inverse (111) sides appeared.'-l8 The correlation of these patterns to the Ga{111) or the As(111) side has already been established by the use of light figures,18-20 by X-ray diffraction near the absorption edges of gallium and arsenic,'lmZ4 and by LEED measurements.25 The geometric structure of these surfaces and the interior of the anodically attacked crystals were observed and photographed with a high-power microscope using oil immersion objectives up to magnification of X1720.

Jan 1, 1968

By G. V. Raymor, James T. Waber, I. Rex Harris

The lattice parameters of a series of fcc alloys of cerium and thorium were measured at 93 " and 298OK. Lattice parameters were also estimated for 171OK. Substantial deviations, y, from Vegard's law were observed. Although y was negative at the two higher temperatures, it was positive and large at the lowest temperature. A variety of models, which have been proposed in the past, were considered, and the calculated values of y were compared with the observed values. The best agreement was achieved with values computed with Friedel's equation. THE purpose of this investigation was to determine the effect of temperature on the lattice parameter and on deviations from Vegard's law of Ce-Th alloys. A large negative deviation from Vegard's law was first observed independently by Weiner, Freeth, and Raynor' and Van vucht2 in the room-temperature lattice parameters of Ce-Th alloys that form a continuous series of solid solutions. This observation was confirmed by Evans and Raynor. The allotropy of unalloyed cerium was reviewed recently by Gschneidner, Elliott, and McDonald. In two subsequent papers,5" these authors reported the influence of various alloying additions on the y= transformation, which occurs below room temperature. Although other rare earths tend to stabilize the double-hexagonal phase, thorium, plutonium, and scandium as solutes tend to stabilize the normal fcc phase. With addition of sufficient thorium as a solute, there is evidence that the formation of is suppressed and it becomes possible to pass continuously with decreasing temperature from the room-temperature phase to the fcc a phase. Thus there is a closed loop which is similar in many ways to the y loop well-known in ferrous alloys. A closed field also occurs in the pressure-temperature "equilibrium" diagram of unalloyed cerium. Because of interest in the effect of thorium additions and their influence on the a and phases, lattice-parameter measurements were made at low temperatures on the fcc phase for a series of alloys ranging from 10 to 90 at. pct Th. The results obtained at three temperatures are shown in Fig. 1. Evans and Raynors analyzed the deviations from Vegard's law in Ce-Th alloys in terms of changes in the occupancy of the 4f electron level in cerium,

Jan 1, 1964

By H. Kreye, E. Hornbogen

An increase in electrical resistivity during aging or after quenching from high temperatures is known in a large number of alloys. Plastic deformation of alloys in this condition leads to a decrease in resistivity. This anomaly has been called the K effect. This effect has been reported in Ni-A1 alloys by several authors.'-4 The nickel-rich solid solution y is in equilibrium with Ni,A1 (y') with CkAu structure. With this alloy it is therefore possible to produce a homogeneous solid solution as well as a coherent mixture of y and y. The changes in resistivity should be determined for these two conditions. In the present literature on the K effect no distinction is made between them, because of experimental difficulties to determine small coherent particles. In the present work transmission electron microscopy and image formation by (100) and (110) superlattice reflection of the y' phase was employed for a detailed determination of the temperature dependence of solubility of aluminum in nickel and the resulting microstructures with alloys up to 15 at. pct Al. The solubility line follows the equation indicating a smaller solubility than given in the literature at temperatures below 700°C. X-ray scattering was used to get evidence for short-range ordering in the homogeneous solid solutions.5 Parallel to the determination of the microstructure electrical resistivity was measured as a function of aging tempera- ture, time, and aluminum content, which led to the following results: 1) Resistivity increases slightly during aging of a homogeneous solid solution which was quenched from a high temperature as a consequence of short-range order, Fig. 1, curve c,. 2) Resistivity shows a maximum during aging of all alloys which are heterogeneous according to the phase diagram, but which were obtained as a supersaturated solid solution by quenching, Fig. 1, curve c,. The increase in resistivity is mainly due to coherent precipitation of y'. In Fig. 2 the effects due to short-range order pN and due to precipitation of particles APT are shown for an aging temperature of 450°C and different aluminum contents. 3) The increase in resistivity depends on the size !f the coherent particles. A critical diameter of 15 5A for the maximum was found for all alloys and aging treatments by extrapolating particle sizes determined by electron microscopy. 4) The maximum of resistivity of the heterogeneous conditions does not occur if particles, larger than the critical size, have formed already during quenching. 5) Plastic deformation destroys short-range order as well as small coherent particles. Therefore a decrease in resistivity is observed if the increase in resistivity caused originally by these phenomena is

Jan 1, 1967

By J. E. Strassner

Oilfield emulsions are stabilized primarily by film-forming asphaltenes and resins containing organic acids and bases. Adding inorganic acids and bases radically changes the physical properties of these films and their emulsion-stabilizing properties. Interfacial films show one of three different physical characteristics when retracted in pendent drop tests. These compressed films have rigid, soap-type or minimum film properties depending on the quantity of asphaltenes and resins in the crude oil and on the pH and composition of the brine. There exists for each crude oil-brine system an optimum pH range over which the adsorbed film exhibits minimum contracted filtn properties. In this range, intmfacial tension is high — frequently near its maximum value — indicating the absence of highly surface-active specier; crude oil-brine emulsions generally show minimum stability; and surfactant requirements for breaking these emulsions are significantly reduced — sometimes no surfactant is needed. About two-thirds of the world's crude oil is produced as emulsions that must be treated (demulsified) to be marketed.' Approximately three-fourths of all domestic crude oil produced must be treated. The percentage of crude requiring treatment increases as fields become older and more water is produced. Demulsification most frequently is attained through use of surfactants, heat and electric treaters. It is estimated that over 75 percent of all oilfield emulsions are broken by chemicals generally containing alkylene oxide condensates. Although acids and bases are known to affect emulsion stability:-' they rarely are used in the oil field except in batch treatment of the most severe emulsions. Nevertheless, pH adjustment by using acids or bases in demulsification has some advantages over other methods. Mainly, it is cheaper. Acids and bases frequently are cheaper to use than surfactants, or can appreciably reduce the amount of surfactant required for demulsification. Secondary advantages are that less oil is lost by emulsi-fication into the aqueous phase, and that less corrosion is encountered when the optimum pH is basic. Limitations to the use of pH include (1) use in brines containing high concentrations of reactive ions, (2) closer supervision for pH control than is required for surfactants and (3) need for corrosion protection when the optimum pH is sufficiently acidic. These factors indicate that the economics of pH con trol in demulsification will be maximized when relatively large treating facilities are needed, when relatively large surfactant concentrations are required to break an emulsion, when a relatively low concentration of the aqueous phase is emulsified in the oil and when the emulsified aqueous phase contains relatively low concentrations of reactive ions. Because there are no broad guide lines for using pH control in breaking oillield emulsions (and because the limited guides available are highly specific and frequently contradictory), this paper will attempt to clarify the principles involved in using acids and bases to break emulsions. These principles also should be useful in refinery separations and in other oilfield applications where stable or unstable petroleum emulsions are involved. Principles of Emulsion Stability Oilfield emulsions generally occur as water droplets dispersed in oil (w/o) and occasionally as oil droplets in water (o/w). These emulsion droplets are usually in the 0.1- to 10-micron range. However, more coarsely dispersed water droplets frequently are present in the emulsion. Pure hydrocarbons and water will not form stable emulsii except in extreme dilutions where the large distance brtween droplets inhibits coalescence. An emulsion breaks because interfacial tension acts to minimize the surface area of the dispersed drops by coalescence. However, emulsions can be stablized for long periods of time by the presence of a third phase that adsorbs at the oil-water interface and inhibits coalescence of the dispersed phase."' Emulsions generally are stabilized by (1) repulsive charges on the surfaces of the dispersed phase and (2) adsorbed films that, being preferentially wetted by the continuous phase, act as a physical barrier to inhibit contact between the dispersed droplets. Both these factors generally are important in stabilizing and in breaking o/w emulsions. However, repulsive charges are less effective in stabilizing w/o emulsions which generally are stabilized by adsorbed films.V or this reason the nature and importance of these films at oil-water interfaces were examined closely; as will be shown, pH changes were found to affect the films significantly, and this work led to laboratory tests of pH- adjustment in emulsion breaking. This paper will present evidence to show that emulsions are stabilized primarily by films that form around droplets

Jan 1, 1969

By J. A. Brierley, Roshan B. Bhappu, D. H. Reynolds, P. H. Johnson

Although the economic importance of recovering copper by leaching of mine work dumps from open-pit operations has been realized for some time, serious attempts to understand and to improve such operations through scientifi research has been made only in recent years. This progress report covers the results of chemical, physical, and biological studies pertaining to the dump-leaching process and discusses salient features and parameters that may be helpful in improving such operations. The dump leaching of low-grade copper ores, as an integral part of the open-pit mining operations in the Southwest, has been practiced for the last 50 years and is increasing in importance as one of the major sources of copper. The recent acceleration in dump leaching can be attributed to: (1) the greater tonnages of low-grade ores mined and dumped at newer mines as well as resulting from increased stripping ratios at the older mines, (2) the relatively small investment required for dump leaching facilities per pound of copper recovered contrasted with expansion of milling facilities to recover equal amounts of the metal by raising tonnage throughout, (3) low labor requirements needed for leaching, and (4) the simple and continuous nature of the process needing little close supervision of trained operators. In the past, the mining companies have not worried about efficiency in dump leaching but have been satisfied with whatever metal recoveries could be made without much effort. However, because of the huge amounts of metal accumulating in the low-grade waste dumps, compared to the relatively small amount recovered annually, an operator today cannot leave dump leaching to chance. What appears to be a simple, empirical process is actually a very complex one involving a large number of critical factors that encompass Several Scientific disciplines, such as physics, chemistry, geology, biology, and hydrology. It is imperative that

Jan 1, 1970

By J. S. Lasater

Resu1ts of experinmental measurernents of heat capacities and thermal conductivities of some typical porous rocks are presented. Measured heat capacities agree closely with va1ues calculated front known chenlical . compositions of the rocks. On the basis of this agreement, heat capacitir.7 of fluid-satttrated rocks were calc~ililted. Therrnal conductivities of the rock samples were measured under varioits conditions of fluid saturation. From these data therrnal dif-fvsivities were calculated. A significant variation of thermal diflusivity with trnlperature is indicated. Knowledge of the thermal characteristics of fluid-bearing porous rocks has become increasingly important with the development of thermal oil-recovery processes. Reliable thermal data for petroleum reservoir rocks are not available and approximate values are generally assumed for reservoir calculations. 'The effects of temperature, pressure and fluid saturation on thermal properties of porous rocks have not been carefully studied. The purpose of the present work was to measure and report the thermal characteristics of some typical porous rocks. A group of eight sedimentary rock samples, including limestone, shale, sandstone and silt-stone, was selected for the study. Properties reported include heat capacities, thermal conductivities and thermal diffusivities. The effect of fluid saturation on these properties was also considered. Determinations of thermal properties require precise measurements which are time consuming and difficult to reduce to a routine basis. Methods have not been developed for measurement of thermal proper-ties under conditions of pressure, temperature, and fluid saturation, which may be encountered in thermal recovery processes. As one approach to these problems, some preliminary work on methods of estimating thermal properties from other more readily measurable characteristics of the rock-fluid system is reported. The samples selected for the studies were oilfield cores from within, or closely associated with oil-productive zones. Descriptions of individual samples are given in Table 1. Clay minerals present in the samples were determined by differential thermal analysis (DTA). Quartz content was estimated from DTA cooling curves. For all but the thermal conductivity tests, a representative 200-gm sample of each core was disaggregated, thoroughly extracted in diox-ane and oven dried at 100°C. The cleaned and dried sample was care- fully split into appropriate portions for the several tests. Chemical analyses of the samples were obtained to permit calculations of heat capacities by methods which are outlined later. Resuits of chenlical analyses are given in Table 2. Heat contents of the test samples were measured by a Runsen-type calorimeter. The heat content of the unknown sample is measured relative to the known heat content of platinum. The apparatus is referred to as a relative error type because of the comparative measurements, and has the advantage of canceling systematic errors. Experimental results are reproducible within 0.5 per cent. A temperature base of 298.16 K is taken for heat content measurements. Measurements were made at five temperatures (260, 440, 620, 800 and 980° F). It was necessary to preheal the sample above the maximum experimental temperature to eliminate volatile constituents. Assuming the weight loss on pre-heat, ing was mostly water, a correction to the observed heat content was made to account for the water originally present in the sample. This latter procedure was followed in the determination of calculated heat contents as will be described later. The apparatus and the method of measure-

Welfare endeavor in connection with both the metal and the coal mines of Utah has shown gratifying progress during recent years and both the operators and their employees are deserving of much credit for the efforts put forth to better living, working, educational and receational conditions in most of the mining camps of the state. In the older metal mining camps of Utah, where the towns are incorporated and independent of the mining properties operating in the vicinity, less opportunity is presented for the companies to exercise efforts looking towards improved welfare conditions than is the case of camps located on company ground and under the full control of operators.

Jan 1, 1925

By H. H. Evinger, M. Muskat

Although the shooting of oil wells for the purpose of increasing production has been practiced since 1866, present-day shooting technique has been arrived at almost wholly by a process of trial and error. The difficulties attending either a theoretical analysis of the problem or an experimental attack become apparent when one actually embarks on a theoretical investigation or attempts to formulate an intelligent experimental program. The literature on the subject consists mainly of descriptions of current practice, scattered eye-witness accounts of events following the shooting of a well, and vague speculations on the mechanical processes involved. In contrast to quarry blasting, the results of oil-well shooting cannot be determined by means of visual inspection, and it is perhaps for this reason that only one attempt at what approaches a direct experimental attack has been reported in the literature.' In these experiments, charges of liquid nitroglycerin were exploded in holes drilled in a sandstone outcrop. In order to observe the character and extent of the resulting fractures, the rock was blasted away so as to expose the original shot holes. After all this had been done it was found impossible to distinguish the fracturing due to the original shots from that due to the subsequent blasting. The enlargement of the holes due to the pulverizing action of the shots was measured and an attempt was made to determine the effectiveness if sand tamping. Only five shots were made and few definite conclusions could be drawn. Some small-scale experiments to deter-mine the effect of tamping were performed by Snelling and IIalL2 Small charges (zo grams) of dynamite were detonated at the bottom of a cylindrical hole in a lead block and the resulting enlargement of the hole was taken as a measure of the effectiveness of the explosion. It was found that when the shot was tamped with a sufficient amount of sand or clay, the volume enlargement was approximately double that found when no stemming had been used. The properties of the explosives have been the subject of much study by the manufacturers, the U. S. Bureau of Mines, and various other agencies. For example, velocities of detonation for many commercial explosives are to be found in the Blasters' Handbook, issued by the Du Pont company. Many other properties are given in a treatise on the subject by Naoum.~ The shock wave that accompanies the detonation of high explosives has been studied photographically by Payman4 and others. The hydrodynamical theory of the shock wave has received much attention, and an extended theoretical treatment is given by Bateman.6 Two aspects of the well-shooting problem will be considered in this paper; namely, the fracturing of subsurface strata, and possible damage to casing. With respect to the former of these, several calculations have been made giving the stresses in the rocks surrounding the shot. In order to arrive at numerical results at all, however, it is necessary to introduce a great many simplifying

Jan 1, 1941

By M. Muskat, H. H. Evinger

Although the shooting of oil wells for the purpose of increasing production has been practiced since 1866, present-day shooting technique has been arrived at almost wholly by a process of trial and error. The difficulties attending either a theoretical analysis of the problem or an experimental attack become apparent when one actually embarks on a theoretical investigation or attempts to formulate an intelligent experimental program. The literature on the subject consists mainly of descriptions of current practice, scattered eye-witness accounts of events following the shooting of a well, and vague speculations on the mechanical processes involved. In contrast to quarry blasting, the results of oil-well shooting cannot be determined by means of visual inspection, and it is perhaps for this reason that only one attempt at what approaches a direct experimental attack has been reported in the literature.' In these experiments, charges of liquid nitroglycerin were exploded in holes drilled in a sandstone outcrop. In order to observe the character and extent of the resulting fractures, the rock was blasted away so as to expose the original shot holes. After all this had been done it was found impossible to distinguish the fracturing due to the original shots from that due to the subsequent blasting. The enlargement of the holes due to the pulverizing action of the shots was measured and an attempt was made to determine the effectiveness if sand tamping. Only five shots were made and few definite conclusions could be drawn. Some small-scale experiments to deter-mine the effect of tamping were performed by Snelling and IIalL2 Small charges (zo grams) of dynamite were detonated at the bottom of a cylindrical hole in a lead block and the resulting enlargement of the hole was taken as a measure of the effectiveness of the explosion. It was found that when the shot was tamped with a sufficient amount of sand or clay, the volume enlargement was approximately double that found when no stemming had been used. The properties of the explosives have been the subject of much study by the manufacturers, the U. S. Bureau of Mines, and various other agencies. For example, velocities of detonation for many commercial explosives are to be found in the Blasters' Handbook, issued by the Du Pont company. Many other properties are given in a treatise on the subject by Naoum.~ The shock wave that accompanies the detonation of high explosives has been studied photographically by Payman4 and others. The hydrodynamical theory of the shock wave has received much attention, and an extended theoretical treatment is given by Bateman.6 Two aspects of the well-shooting problem will be considered in this paper; namely, the fracturing of subsurface strata, and possible damage to casing. With respect to the former of these, several calculations have been made giving the stresses in the rocks surrounding the shot. In order to arrive at numerical results at all, however, it is necessary to introduce a great many simplifying

Jan 1, 1941

By Å. Sterten, R. Tunold, J. Brun, K. Dalatun

c axis compression behavior of beryllium single crystals at three purity levels under hydrostatic pressures up to 27 kbars was determined. Extensive non-basal slip, observed by two-surface trace analysis and transmission electron microscopy, occurred under a hydrostatic pressure of about 12 kbars (175 ksi) for the high-purity (twelve-zone pass) material and at about 19 kbar (275 ksi) for the lower-purity (zone-leveled) material. Prismatic loops with a (c + a) Burgers vector were observed in association with second-phase parti- A principal factor limiting the use of beryllium is its brittle behavior when tested at the usual strain rates (E = 10-4 sec- 1) at temperatures below about 200°C and under impact conditions at temperatures in excess of 200°C. It has been proposed' that the brittle-ness of beryllium is associated with the lack of a sufficient number of independent slip modes and the absence of a slip mode with a Burgers vector out of the basal plane [presumably (c + a) pyramidal slip mode] and to the ease with which beryllium cleaves on the basal and second-order prism planes. The absence of pyramidal slip has been attributed to a high Peierls-Nabarro stress associated with the motion of dislocations with a (c + a) vector and the ease with which cleavage occurs on the basal and second-order prism planes. The experimental evidence in support of the proposed explanation for the brittleness of beryllium is far from complete; for example, that the ductile-to-brittle transition in polycrystalline beryllium is associated with the operation of profuse (C + a) slip has not been unequivocally established. The occurrence of (c + a) slip ({1122}(1123)) has been experimentally established2-5 under conditions where basal and prism cleavage are restricted in a c axis compression test. In these investigations (C +a) slip was found in high-purity beryllium single crystals tested in c axis compression* at 200°C and in Be-4.4 pct Cu and Be-5.2 pct cles in the lower-purity materials tested. The loops were related to surface "extrusions" observed on many of these same specimens. Nonbasal dislocations operating on (1122) planes with a (c + a) Burgers vector were observed. The presence of c and a dislocations together with (c + a) dislocations suggests that the (c + a) dislocations dissociate presumably on unloading or after failure of the test crystals to c and a dislocations. terial, (c + a) slip has only been observed near the the fracture4 surface in room-temperature c axis compression tests. Fracture in these tests occurs without measurable plastic flow, as determined with a strain sensitivity of 10"6. Since it has been shown for many metals that the application of hydrostatic pressure suppresses fracture,?-' it was felt that studying the behavior of unalloyed beryllium single crystals stressed in c axis compression under a hydrostatic pressure would reveal whether (c + a) can occur if fracture was prevented, and that it might elucidate the role of (c + a) slip in the ductile to brittle transition. Evidence that (C + a) slip is associated with increased ductility in a high-pressure environment has been found in stress-strain tests on poly crystalline beryllium.10 The present paper describes a study on the influence of a hydrostatic pressure environment on the occurrence of (c + a) slip in beryllium single crystals. Material of two purity levels was tested in c axis compression over the pressure range ambient to about 27.5 kbars.* 1) MATERIAL PREPARATION AND CHARACTERIZATION Two lots of low-purity single-crystal beryllium were used. The first lot was "ingot secondary refined grade" and designated lot A. The second lot (lot B) was produced by a two floating zone pass zone-leveling operation in an argon-filled sealed quartz apparatus on a 1-in.-diam by 12-in.-long bar of Pechiney secondary refined-grade vacuum-cast and hot-extruded material. The high-purity material (lot C) was made by traversing twelve floating zone passes through a similar bar of Pechiney secondary refined-grade vacuum-cast and hot-extruded material. In a series of spark cutting and lapping procedures,11 single-. crystal specimens some 0.12 in. sq by 0.30 in. high were made with the sides Parallel to the first- and second-order prism planes and the basal plane within 3' of arc of the top and bottom surfaces of the specimen. Such an accurate orientation is necessary because of the large difference in resolved shear stress

Jan 1, 1970

By Om P. Garg

During the period between 1970 and 1974 the Iron Ore Company of Canada had embarked on a detailed program to evaluate all aspects of mine design work for its open pit mines around Schefferville, located both in Quebec and Labrador, Newfoundland, Canada. One of the main conclusions was that the majority of the slope angles for the ultimate pit walls could be steeped. During the period 1975 and 1976,five (5) open pit iron ore mines were redesigned using the steeper slope angles up to 55 degrees. Initially these pits were designed at slope angles varying between 37 degrees and 45 degrees due to the generally fractured and leached nature of rocks in the area. During the active mining phase between 1976 and 1979, the stability of the steeper ultimate pit walls was monitored. The mining of ore was successfully completed in 1978 and 1979 in three pits. This of course, resulted in a significant savings due to a reduction in the quantity of waste that had to be removed. The successful pit slope redesign project was a co-operative effort between the Federal Government, Universities and the Iron Ore Company of Canada.

Jan 1, 1983

By R. J. Brown

Design of a submarine pipeline system is governed by many factors, one of which is the effect of transverse horizontal currents on the pipeline structure itself Although this feature alone can be of utmost importance to the life span and stability of the underwater pipeline, it is usually the least recognized, with these hydro-dynamic forces being either completely overlooked or grossly underestimated. In an attempt to supply the methods and means for stabilization of sub-marine pipelines, much capital has been spent by pipeline companies. Design criteria incorporated by these organizations extend over a broad spectrum of engineering with bases varying from pure theory to cut and dry methods. A history of numerous failures has substantiated the postulate that many of these submarine pipelines have been underdesigned from the stability standpoint. By the same token, equally as many have been excessively overdesigned with resultant excess expenditures. An attempt has been made in this paper to establish the magnitudes of these hydrodynamic forces by measuring the lateral current-induced differential pressure distribution around the periphery of the submarine pipeline. INTRODUCTION The expenditure of money for research by corporations obviously requires beneficial results to justify the investment. One of the functions of the engineer is first to make the problem known and then to provide a means of solution at the least possible cost. The initial procedure is to investigate all pertinent published technical articles on the subject to determine if this problem has been previously solved. If resolution of this problem is not obtainable, the next course of action is to evaluate through experiments these forces and their magnitudes. On the specific subject of drag and lift, the accumulation of data is provided from three separate and distinct sources: from experience, from theoreticians and through experimental observations. The experience source has proved costly with money wasted either because of underdesign and failure or excessive expenditures for overdesign, and has not been sufficient to form a definite conclusion on these hydrodynamic forces. The pure theoretician is often not completely cognizant of the situation and his works bear little adaptation to the real problem. The experimentalist has his own problems with regard to obtaining results from small-scaled models and successfully adapting them to the larger prototypes. Each method has its own advocates who diligently adhere to their own separate routes as being the only means of resolving this problem. However, a review of the various methods of analysis leads one to the conclusion that if the advantages of all three are combined, a reasonable solution to this problem can be reached. Briefly then, the problem is to obtain the magnitudes of the forces on the submarine pipeline subjected to a lateral current by investigations of previous design considerations, by a study of existing theoretica1 data and by appropriate experimentation. This paper deals mainly with obtaining experimental data and the interweaving of theoretical and experience factors for resolution of these forces. APPARATUS AND PROCEDURE These tests were performed in 1961 at Collins Construction Co.'s main office near Port Lavaca, Tex. Test equipment consisted of a steel tank 3 ft high by 4 ft wide by 40 ft long, with several pumps circulating the water through the tank via suction lines from the downstream portion of the tank and discharging from the pumps directly into the upstream end of the tank. For reduction of turbulence, a wire section was constmcted in the upstream portion and straightening vanes in the form of pipes, screens, etc., were used to reduce the vortex and eddy action in the tank (Fig. 1). A venturi was built at the test specimen for obtaining velocity sufficient to simulate actual conditions. This full-scale test was initiated to eliminate the error introduced in modeling and obtain a truer picture of forces actually encountered. Six- and 10-in. specimens were prepared by

Jan 1, 1967

By C. W. Davis, R. S. Dean

AMONG naturally occurring inorganic compounds, magnetite has many unusual and interesting properties, and it is the purpose of this paper to call attention to these properties and review possible uses of magnetite that might be based on them; in other words, to see what uses may be found for magnetite as a physical rather than as a chemical entity, as a mineral rather than as an iron ore. The Mineral Physics Studies initiated in the Metallurgical Division of the U. S. Bureau of Mines a few years ago gathered together much information on mineral properties, and they are therefore the principal source of material for this paper. Magnetic Properties Of Magnetite And Possible Uses As A Magnetic Material Magnetite is unique among minerals for its great magnetic susceptibility, approximately one-third that of soft iron, and some magnetites are permanent magnets, or lodestones. The literature contains many measurements of magnetic properties of individual magnetite crystals, but no systematic survey of the effect of mechanical preparation and heat-treatment was available until the recent investigations of the Bureau of which included not only susceptibility but coercive force and remanence as well. For the purpose of orientation, Table 1 gives the magnetic properties of several samples of magnetite and of a few other substances3. This table indicates that when ordinary magnetite is powdered it decreases in susceptibility and increases in coercive force and remanence, approaching the properties of lodestone. The properties of lodestone are in fact probably due to the development of very large internal surface on fine grain size4.

Jan 1, 1937

By Nelson P. Hulst

To those who have had the happy privilege of friendship with George W. Goetz, the announcement of his death has brought great sadness. He was born in Milwaukee, Wisconsin, February 17, 1855, and died January 15, 1897. In his boyhood days, when I first came to know him, his frank, trustful manner; his eyes brimming with truthfulness; his eagerness, never obtrusive, to gain knowledge from all whom he met; and his equal readiness to give without ostentation of his store, constituted a personality which at once commanded confidence and won friendship. I am told that as a scholar of five years he was conspicuous for brightness, a show-pupil, who was called on to recite when visitors were present at school. Yet this in no way spoiled him. His modesty was too strong a trait in his character to be overcome by any attention which might, be expected to arouse vanity. In his simple-heartedness he was pleased then, as he always was in his maturer years, to give of his knowledge for the gratification of his listeners, with never a thought of himself. So strong was this characteristic that in a brief autobiography, in the form of a letter to his wife and children, found among his papers, he excuses himself to them for recounting what he had accomplished in his life-work. As a preface to this autobiography (which, it seems, was prepared on the eve of a sudden journey to California, taken February, 1895, for his health) he says: " I am writing this rather hastily, and I

Jan 1, 1898

By K. Mukherjee

A quasi-thermodynamic calculation is presented for estirt~ating vacancy Parameters in fcc metals. For fcc metals the equilibrium vacancy concentration at the melting point can be approximated by a constant mole fraction. The Gibbs free energy of formation of the vacancies can then be expressed as a simple function of the absolute melting temperature alone. From this description the formation energy Ef, the vibrational entropy Sv, and the formation volume of a vacancy can be calculated in terms of known thermodynamic parameters. The calculated values are in good agree-rnent with available experimental results. IT appears that many of the physical parameters associated with lattice defects can be empirically related to thermodynamic melting parameters.'-7 Besides the implicit correlations between melting phenomenon and point defects, the melting temperature itself at atmospheric pressure can be used as a reference temperature for the purpose of comparison of vacancy concentrations in a given crystal class. The concentration at the melting point then corresponds to the maximum vacancy super saturation in the crystalline state at a fixed pressure. For pure fcc metals such as Au, Cu, Al, Ag, Pb, and Pt the mole fraction of vacancies at the melting point8 is of the order of 10*"3 to 10"1. The equation expressing the equilibrium vacancy concentration at the melting point contains three parameters: the formation energy, the vibrational entropy, and the absolute melting temperature, see Eq. [2]. Since these three parameters cover a wide range of values8 in the above-mentioned metals, it can be assumed that in other fcc metals, for which no reliable data are available, the mole fraction of vacancies at the melting point most likely lies in the range 10~3 to lO"4. This is then the basis of the calculations described in this article. Within this range the mixing entropy can be linearized and the vibrational entropy, the formation energy, and the vacancy formation volume can be calculated in terms of known thermodynamic constants. 1} LINEARIZATION OF MIXING ENTROPY The Helmholtz free energy of a crystal containing n vacancies at the melting point can be writteng as where Ef, T,, k, and S, are the formation energy of a vacancy, the absolute melting temperature, Boltz-mann's constant, and the vacancy formation entropy, respectively. After applying Stirling's approximation in Eq. [l] and minimizing with respect to n where (n/N), is the equilibrium vacancy concentration in mole fraction at the melting temperature at 1 atm pressure. If instead of setting (6~/6n) = 0 immediately after Stirling's approximation in Eq. [I], the configurational partition function is simplified, then some useful and significant results can be obtained by utilizing the experimental inforrnation After applying Stirling's approximation and rearranging is plotted as a function of (n/N) in Fig. 1. The points, not all of which are shown, are fitted by a straight line substituting from Eq. [5] into Eq. [I] and minimizing with respect to n combining Eqs. [6] and [2] It must be emphasized that Eq. [7] is only a crude approximation based on an oversimplified model of

Jan 1, 1967

By Frank C. Kelton

A method is outlined for the analysis of large cores, developed primarily for the purpose of obtaining reliable data on fractured or vugular limestones. Porosity and fluid saturations are determined by a modified Dean-Stark extraction after initially bringing the samples to 100 per cent liquid saturation by a vacuum-pressure method. Horizontal permeabilities on the whole samples are determined in two directions, parallel and perpendicular to the di-rection of principal fracturing. Results are presented for various types of formations. A comparison is made between data obtained by this special method and the method of conventional analysis, and discussion is given of the relative advantages and limitations of each. In view of this comparison a modified method for the analysis of fractured and vugular formations is proposed, which method retains the advantages of the previously outlined techniques but gives promise of speeding up the analysis. INTRODUCTION For many years the greater part of the production in the Permian Basin was from formations of Permian and Pennsylvanian age. While production from these formations is still the predominant production. deeper prospecting has brought to light older formations with oil productive characteristics. Attempts to core these deeper horizons were at first usually characterized by poor recovery. The old rule of thumb, "good core recovery — poor well" was originated and remained in effect until recently. With the advent of diamond coring and the increased efficiency in drilling and coring operations. the old adage has lost its significance. Formations of Devonian. Silurian and Ordo-vician ages were successfully cored with varying degrees of recovery. The cores thus obtained were surprising and in some case; disappointing. Good recovery from these formations led to speculation as to the feasibility of analysis and the meaning of data obtained from conventional analysis. Commercial laboratories were engaged to analyze these cores. and their results indicated that data obtained by conventional methods would be of little value. From visual inspection it was apparent that in many cases the effective porosity for storage of hydrocarbons. and permeability. were contained largely in fractures and solution cavities rather than in the primary crystalline structure of the formation. In other cases the solution cavities augmented the effective porosity of the primary crystalline structure, or fractures enhanced the permeabiilty of the latter so that the formation might respond favorably to acidization and become commercially productive. Since the spacing of the cavities and fractures was often comparable to the core diameter, it was evident that the entire core should he analyzed instead of small fragments. On the basis of these observations, commercial laboratories were requested to devise a system of analysis which would yield data of practical value. Pro- cedures have accordingly been developed which seem to meet this requirement, and to date nearly 12,000 large core samples have been analyzed. It is the purpose of this paper to describe the methods used, to present typical results for several fractured formations and to compare the data obtained by this special analysis with that obtained by conventional analysis. Certain modifications and alternative procedures are finally suggested to speed up the analysis. CORE ANALYSIS PROCEDURE Fluid Saturations and Porosity The core sample, in segments up to 15 in. in length. is marked, weighed and examined under ultra-violet light to determine the presence of oil saturation. If present, the approximate quantity of oil and its location on intercrystalline, fracture or vugular surfaces is noted. This information is carefully recorded. The degree of fracturing and/or vugular development is also noted. The sample is then placed in a pressure cell and the air evacuated with a high speed vacuum pump. This evacuation is continued only long enough to reduce the pressure to approximately the vapor pressure of water in order not to remove excessive amounts of water. Water is admitted to the cell and allowed to penetrate the sample under atmospheric pressure, filling the pore space initially occupied by air and replacing the small amount of water removed by evacuation. Pressure up to 200 psi is applied to force water into the smaller capillaries, and the sample is left sub-

Jan 1, 1950

By Hiroshi Kato, Shin’ichi Nagashima, Hiroshi Takechi

The preferred orientations detleloped during cold rolling, annealing, and hot rolling of low-carbon steel sheets have been investigated by means of an inverse pole figure technique. And X-ray line profile meas-urerrlents were made for the study of the factor which causes the textural changes between cold-rolled and recrystallized sheets. From ND (sheet normal divection) and RD (rolling direction) inverse Pole figures tlze axis detisity change with increasing cold reduction was measured and the Preferred orientations were analyzed. These results can be explained by crystal rotation due to slip during rolling deformation. The ND axis density change during annealing of cold-rollitig sheets is contrary to the change observed in the case of rolling. It was found that the orientation dependency of stored strain energy resulting from cold rolling apparently corresponds to the textural changes during recrystallization. The texture in hot-rolled sheets was found to be influenced by finishing tenlperatltre. In a sheet kol-rolled below the Ar, temperature a significant differernce in texture between the surface and central layers was obtained, the former having {hkl}(111} and {110 )(uvw) orientations and the latter having {pqr}( 110) orientation. A large number of investigations1 6 have been made on the textures of iron and low-carbon steel sheets, and, since it was shown7 13 that preferred orientations are closely related to deep drawability of steel sheets, studies14" 7 on the influence of production processes upon textures have been made from the standpoint of industrial interest. Generally, the textures in low-carbon steel sheets have several components of preferred orientations, but the overlapping of poles makes it difficult to analyze texture quantitatively from pole figures. On the other hand, an inverse pole figure directly expresses quantitative values of components of preferred orientations as the density of a certain sample axis with respect to the crystallite coordinates. Such a texture representation is desirable for a study of deep drawability. The purpose of the present work is to use both inverse and conventional pole figures, with emphasis on the former, to clar~fy the textural changes ~n low-carbon steel sheets by the production processes of hot rolling, cold rolling, and annealing. And the factor causing the textural changes during annealing is studied using an X-ray diffraction line profile technique. EXPERIMENTAL PROCEDURE Sheet specimens for study of cold rolling and annealing textures were taken from a hot-rolled strip of rimmed steel 2.7 mm thick. The chemical composition is shown in Table I. Although the study of cold-rolling textures requires a suitable material with random orientation, it is difficult to produce a perfect random one. But the used specimens, obtained from the hot-rolled strip with a finishing temperature higher than Ar3, were nearly random, such as shown in Fig. 15. These were cold-rolled to various reductions by a 4-high rolling mill with 150-mm-diam work rolls and 300-mm-diam backup rolls. The influence of hot-rolling conditions such as finishing and coiling temperatures on textures of hot-rolled strips was studied. The chemical compositions of these hot coils are given in Table I1 and the hot-rolling conditions are given in Table 111. inverse Pole ~i~ure -~easurement. Two methods for determining inverse pole figures with high precision have been proposed. The first, by Jetter et a1.,18 consists of obtaining mean densities of divided regions in a unit stereographic triangle by solving simultaneous linear equations to approximate the integral relation between conventional and inverse pole figures. The second, proposed by ~oe'~-'~ and Bunge,22'23 consists of determining an expanded series of spherical surface harmonics which express axis densities from several sets of pole distribution data. Both methods require laborious numerical calculations which make them unsuitable for practical use. However, the axis densities of the locations corresponding to low Miller indices in a unit stereographic triangle can be obtained

Jan 1, 1969