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By Donald E. Cummings

MEASURES appropriate for the control of the silicosis hazard in mining cannot be formulated precisely, but sufficient has accumulated during the past quarter century to permit the suggestion of useful, though partly empirical, rules for its alleviation. The industrial hygienist today recognizes that the peril incurred by the inhalation of harmful dust is a function of two variable factors-the degree of harmful exposure and the specific susceptibility of the exposed individual to pulmonary injury. Control of the danger arising out of prolonged contact with pernicious air- borne particulate matter is consequently best exercised by influencing both of these recognized variables. Obviously the problem has two broad aspects-one, medical; the other within the province of the engineer. I-FACTORS COMPRISING THE DEGREE OF INDIVIDUAL SUSCEPTIBILITY Thorough investigations conducted among miners who have labored for years in the presence of recognized silicosis hazards usually reveal an impressive difference in the injury incurred by men whose exposure to dust has been nearly identical. After a quarter century underground, one individual is short of breath and incapacitated with miners' complaint, while a fellow workman suffers no pulmonary embarrassment and is in good health. Physicians ascribe this oft-observed difference in reaction to individual susceptibility and express a universal regret when they deplore the fate that chose to make the predisposed youth a miner rather than a farmer. To trust the health of miners to fate at the present time is even more unfortunate, because many of the factors that influence man's susceptibility to dust are known, and can be accurately determined by competent medical methods. Among the most important factors comprising susceptibility to injury by dust are the anatomical peculiarities of the individual's respiratory mechanism, his physiological response to the inhalation of dust, his previous dust exposure, the existence of pulmonary infections or other pathological processes in his lungs, his age,

Jan 1, 1938

C. M. Kay, Chairman L. W. Moore, Post Chairman C. W. Conn, Vice-Chairman R. W. Shearman, Secretary-Treasurer BLAST FURNACE, COKE OVEN, AND RAW MATERIALS COMMITTEE F. C. Anderko, Chairman James Chisholm, Past Chairman W. F. Huntley, Senior Vice-Chairman W. O. Bishop, Vice-Chairman R. W. Shearman, Treasurer D. C. Brown, Secretary IRON AND STEEL DIVISION Gerhard Derge, Chairman J. J. Golden, Past Chairman B. M. Larsen, Chairman-Elect R. W. Shearman, Secretary-Treasurer THE METALLURGICAL SOCIEN OF AIME J. S. Smart, Jr., President C. C. Long, Past President K. L. Fetters, Vice-President T. D. Jones, Treasurer R. W. Shearman, Secretary

Jan 1, 1961

WILDER D. BANCROFT,* Washington, D. C. (written discussion?).¬In two-phase systems there are three possibilities and Mr. Alexander has only considered two. We may have the first phase the internal one and the second the external one; we may have the first phase the external one and the second phase the internal one; and we may have both phases continuous. This last case occurs when we have a roll of wire fencing standing in the air; the wire is continuous and so is the air. It is quite probable that this case occurs very often in alloys and it it, therefore, important that it should not be overlooked. With gulch,

Jan 3, 1919

By W. E. Mitchell

The ore that is being treated by the present plant lies between the leached zone, or capping, and the mixed sulfide and oxide zone. The principal copper minerals are chalcanthite (CuS04.5H20), brochantite (CuSO4.3Cu (OH)2 and atacamite, (CuC12.3Cu (OH)2). There are, in addition, some other minerals such as cuprite and kröhnkite (CuS04. Na2S04.2H20). These minerals, with many others, occur in a greatly crushed granodiorite rock. most of the copper-bearing minerals occur in the cracks and veinlets, but there are disseminated values and it is probably the relative proportion of these that accounts for some otherwise unexplainable variations in extraction. The entire mineralization of the ore is complex and varies with depth. This variation, the problems presented thereby, and the effect of various constituents of the ore will be taken up in detail. An analysis of :in unweighted composite of the ore treated during 1927 follows: I'Lr Cent. Per Cent. Per Cent. Cu............... 1.58 S................. 2.10 Mo............ 0.01 SiO? ............. 66.10 HNO3 ........0.03 As............ 0.005 Fe.......... 1.41 C1 .............. 0.05 Sb............. 0.005 CnO ..... 0.20 Na................ 0.80 Ba............ 0.01 A1203 .......... 17.70 KI.............. 4.80 H20............ 0.70 mgO.............. 0.68 Mn............... 0.07 0 in sulfates. . . . 3.94 Total..... 100.19 The most important constituents of the ore, as indicated by experience to date, are: (1) The total copper content; (2) the acid-insoluble copper; (3) the acid-making copper mineral, mainly the chalcanthite; (4) the chlorine; (5) the nitrates; (6) the soluble iron; (7) the soluble molybdenum. The total copper content needs no discussion. In Table 1, the values are weighted averages calculated from individual charge analyses. The acid-insoluble copper directly affects the extraction, as the present leach recovers practically no acid-insoluble copper. In Table 1 the values are unweighted averages of the analyses of monthly composite samples. The acid-making copper mineral affects the amount of copper that can be dissolved from the ore without neutralizing acid in the solution. The

Jan 1, 1930

By George S. Rice

GROUND movement from mining, whether it be for coal, metal, industrial minerals, or .oil, will always present many difficult problems. These are especially serious when valuable surface improvements may be badly damaged. The mine itself, if mining methods are not suitable to the formation, is subject to heavy falls of the main roof in the working places; and with certain structural conditions the movements may cause in coal mines disastrous bumps and outbursts of gas, and in deep metal mines rock bursts. In open-cut work rock and earth slides may result. Absolute prevention of ground movement from mining is impossible unless large pillars are left unmined,

Jan 1, 1937

By J. E. Brantly

THE oil-producing industry may logically be 'divided into four independent branches: (1) Acquisition of possible productive lands by lease, fee purchase, concession, or otherwise and the perfection of titles thereto. (2) Studies of the geology of the properties, leading to the location of exploratory wells. These involve reconnaissance and detailed surveys and the use of geophysical instruments, where conditions do not permit surface determination. (3) Drilling of exploratory or test holes and, later, exploitation wells. (4) Actual recovery of the oil from the wells by flowing, pumping, or other methods. These four divisions of the industry are unrelated in detail of accomplishment, but they are entirely complementary, one to the other, and must, in any efficient' organization, harmonize in their respective efforts toward the desired ultimate end. The relative order for the first two branches is not necessarily the proper one; in fact one should have knowledge of the favorable possibilities of a given property before it is acquired, and preferably, also, final opinions as to then proper location for an exploratory well, if such is justified in the light of

Jan 1, 1937

By R. C. Rumble

To /neet the need for a subsurface flowmeter capable of measuring low rates of flow, a new type flowmeter has been built and tested in the field. This instrument is self-contairzed, can be run on a wire measuritzg line, and may be run through 2-in tubing. It consists of a rotameter flow-measuring assembly used in conjuncfion with a conventional subsurface instrument clock and chart. Integral with the tool is an inflatable packer which, by effecting a seal between casing and tool, diverts all fluid through the metering assembly. Packers of different size adapt the tool to different sizes of casing or liner. The flowmeter is capable of measuring rates of flow as low as 4 BID. The flowmeter has been run experimentally in seven wells. It has yielded satisfactory resrrlts in five of the wells, and in the other two it failed to operate because of loose sand in the hole. INTRODUCTION One of the oldest problems facing the producing branch of the petroleum industry is the location of depths of entry of fluid into a wellbore and the determination of the amount of fluid entering at each depth. This problem is often encountered in oil and gas wells completed in single producing horizons as well as in multiple pays; it is a common problem in oil wells which produce excessive volumes of gas. Several subsurface instruments designed to detect and meter flow in the producing interval of wells have been described in the literature.1,2,3,4 Most of these, however, were apparently intended for use in wells producing at relatively high rates of flow, and consequently lack sensitivity to low flow rates. Because of this and of other possible disadvantages inherent in these instruments, development of the subsurface flowmeter described in this report was undertaken. DESIGN OF FLOWME'I'ER Design Requirements In considering the requirements for a flowmeter that would not be subject to the limitations of devices existing at the time work was started, attention was first given to the size of the tool. Such an instrument should be of sufficiently small diameter that it could be lowered readily in 2-in tubing in a producing well. The flowmeter should contain a recording unit so that it might be run on a wire measuring line with conventional reeling equipment. It should not be too long to be accommodated by a portable lubricator of the type used for running conventional subsurface instruments. The metering mechanism of the flowmeter should not be affected appreciably by the viscosity or density of the flowing fluid. Such an instrument should record flow rates in the range from less than 10 B/D to over 100 B/D. To achieve this, a packer should he provided to divert through the instrument all fluid flow in the wellbore. This packer should be of such nature that in the event of excessive flow the fluid would bypass the instrument instead of forcing it up the wellhore. General Description A flowmeter incorporating most of the desired features outlined above was developed and built. The instrument is an elongated tubular device terminated on

Jan 1, 1956

By R. W. Raymond

FOUR portraits have recently been hung in the rooms of the Institute, in recognition of four illustrious men with whom we, as mining engineers and metallurgists, may claim fellowship. LUTHER. Martin Luther is often spoken of as a miner's son; but it is less generally known that John Luther, his father, was, in a small way, a metallurgist as well as a miner, and that Martin Luther himself, in his youth, worked in a forge or bloomary established by his father at Mansfeld, Saxony. Since this is the only manual occupation on his part of which we have any record, it is fair to assume that the great scholar and reformer derived from his work in this department the practical familiarity with the conditions of human labor so abundantly evinced in the homely illustrations which accompany even his serious arguments, and in the witty apothegms of his famous "table-talk." At the same time, I must confess that 1 have not been able to find in any of the works of Luther distinct allusions to mining or metallurgy. KÖRNER. Theodor Körner, a student at the Mining Academy of Freiberg, Saxony, threw himself into the German War of Freedom in the first decade of the 19th Century. He was a poet of no mean rank ; and his " Song of the Sword " is one of the great lyrics of literature. This poem was written but a few days before he died in battle. In many respects, Körner may be compared with our American hero Theodore Winthrop, who similarly met a glorious fate, and left behind him prophetic indications of genius, of which his premature death prevented the complete fulfillment. I am informed by a member of the Institute that Körner's admirable collection of minerals is still preserved at Dresden.

Nov 1, 1908

By H. T. Clark

Within the last twenty years at least three sets of lattice constants for the room temperature (alpha, hexagonal close packed) phase of titanium have been reported in the literature. These values, summarized in Table 1, differ one from another by amounts far greater than can be explained on the basis of inaccuracies in parameter measurements. This paper presents new values determined for high purity titanium. It also details the effect of two elements, oxygen and nitrogen, on these parameters and shows that two of the previously reported values are probably in error because of the presence of one or both of these elements in the material used for examination. Preparation of Samples The titanium+ used for this study was prepared by the thermal decomposition of titanium tetraiodide7 on a hot titanium filament. This titanium rod was prepared for X ray examination by melting about 10 g in purified argon in an electric arc furnace on a cold hearth. This cast button was cold rolled to 0.040 in. thick sheet, cleaned, annealed in vacuum at 1000°C and cold rolled to 0.020 in. thickness. About 0.003 in. of surface material was then removed by hand grinding on papers to remove any contamination caused by the rolls and the sample was bent to the radius of the focusing camera. The sample was then vacuum annealed at 600°C, a temperature just high enough to cause recrystallization, producing a fine grained structure. Such a structure is essential in sheet specimens prepared for focusing cameras in order to have a sufficient quantity of grains to develop continuous diffraction lines. The use of sheet specimens rather than powder samples appears to be essential for the X ray examination of titanium. This is because of titanium's exceptionally high gettering power and its rapid absorption of adsorbed gases, water -vapor, and the like at annealing temperatures. While the effect of this contamination may be neglected for sheet specimens, its effect on 200-300 mesh powder is appreciable. Titanium alloys of oxygen and nitrogen were prepared by a technique simi- lar to that described above except that the required amount of the highest purity titanium oxide or nitride available was added prior to melting in the arc furnace. These materials were added by placing them in holes drilled in the titanium. A small weight loss invariably occurs during the melting of these oxygen and nitrogen alloys. This is believed to be due entirely to the loss of some of the powdered compound in the blast of the electric arc, an assumption which is justified on the basis that there is no weight loss during the melting of titanium metal and that wet analyses for nitrogen on representative samples have checked with the calculated analyses when it was assumed that the entire loss during melting was due to the loss of titanium nitride powder. These alloy buttons were reduced to sheet in the same manner as used for the unalloyed titanium. Experimental Procedure A North American Phillips 12 cm diam symmetrical precision focusing vacuum camera and copper radiation

Jan 1, 1950

By Clark L. Corey, Bogdan Lisowsky

Electrical resistivity, X-ray line positions, degree of order, and microstructures have been investigated for Ni-A1 alloys near the Ni3Al composition. The results indicate that Ni3Al undergoes disordering between 1250oC and the mp; also supersaturated y, produced in y + y' alloys by gas quenching, is extensively ordered prior to y' (Ni3Al) phase separation. The latter reaction, if not both, must follow the cooperative phenomena model. Shifts in line position as a function of quench-indulced super satulration are shown. Lattice pavarneters of equilibriunz and nonequilibrium phases are given. THE objective of this investigation was to determine the mechanism and kinetics of the reactions which occur in Ni3A1 and hypostoichiometric Ni3A1 alloys. The results are of particular significance relative to pre-precipitation phenomena. Early work on Ni-A1 binary compositions near the Ni3A1 composition (13.6 wt pct Al) has been adequately reviewed by Hanssen,1 whose phase diagram is presented in Fig. 1. williams2 verified the suggestion made by Taylor and Floyd3 and others4 that y', Ni3A1, may precipitate coherently on (100) planes of the y phase (see Fig. 1 for phase nomenclature); he further suggested a two-step precipitation mechanism consisting initially of probably short-range ordering followed by actual precipitation of y'. The precipitation stage in low-aluminum hypo-eutectic compositions has been studied by a number of investigators;*"7 short-range order or "zone" formation have been suggested as explanations for various diffuse X-ray scattering effects. The ordering reaction in Ni3A1 alloys is characterized by a) a very rapid rate of ordering in nonstoi-chiometric compositions, b) absence of a disordered phase region for the stoichiometric compound, y', or Ni3A1, c) precipitation phenomena as a dominant aspect in hypoeutectic alloys, and d) an increase in elec-trical resistivity on ordering.' The latter two factors were found by Newkirk to characterize ordering in Co-Pt, for which an extensive and detailed analysis was made.' An electrical-resistivity increase on ordering has also been reported for cuAu3.10 PROCEDURE Ni-A1 alloys in the form of 1300-g chill-cast ingots were prepared by vacuum melting electrolytic nickel and high-purity (99.99 pct) aluminum. Very small heats prepared from high-purity carbonyl nickel, supplied through the courtesy of Dr. Goff of the Naval Research Laboratory, were used for comparison with the larger ingots and no differences were noted. The cast material was homogenized in purified argon for a minimum of 72 hr at 1200°C and water-quenched from 1350°C. Compositions studied are given in Table I. The 10 pct A1 alloy was both hot- and cold-rolled. X-ray superlattice line intensities and peak positions were obtained from -270 mesh filings, using CuK, radiation with a LiF crystal monochromat adjusted to receive both 01 and a2. One-degree slits and a 1/8 deg per min scan rate were used to record line traces. A standard tungsten powder, obtained through the courtesy of G.E. Research Laboratory, was used to calibrate line positions.

Jan 1, 1968

By A. L. Slaughter

The Homestake mine, located in western South Dakota, was discovered in 1876. The first reported production was in I 878. Total production through 1965 is 6,554,249 troy ounces of silver and 27,961,276 troy ounces of gold, worth $987,000,000 at present prices. Precambrian sedimentary formations at Lead total 20,000 feet. The Poorman Formation, the oldest, is chiefly ankerite carbonate. The Homestake Formation is iron-magnesium carbonate. The younger formations are argillaceous with some quartzites. The Cambrian Deadwood Formation unconformably overlies the Precambrian. All are cut by Tertiary intrusives. Sideroplesite schist of the Homestake Formation was converted to cummingtonite schist in the zones of higher-grade metamorphism. The Precambrian rocks show the effects of extreme isoclinal folding. A second stage of folding ( cross folds) may have been caused by the Tertiary intrusives. All folds plunge to the southeast. The Homestake ore bodies are pipe-like replacements of the Homestake Formation in zones of cross folding. It is believed that dilatation of the schists has increased permeability in these zones. Chloritization of the schists is the most widespread effect of the mineralization which is divided into four stages. Principal minerals of the first stage are quartz, chlorite, and arsenopyrite; in the second stage, quartz, ankerite, and pyrrhotite. In the third stage only pyrrhotite was deposited. The fourth stage followed the intrusions of Tertiary dikes and deposited mostly pyrite and calcite. Gold accompanies all stages and is always the last mineral to be deposited. It is most closely associated with arsenopyrite of the first stage but can be interpreted as having been deposited during the fourth stage and superimposed on the products of the earlier stages.

Jan 1, 1968

By E. V. Watts

The D-7 zone of the Ventura Avenue field is of special interest because the initial reservoir pressure at 92.00 ft nearly equaled the pressure exerted by the overburden. While the phenomenon has been observed elsewhere in the world, there is no record of a previous case in California. Such high pressures have been attributed to sealing of the reservoir, followed either by emergence of the beds or by compaction of the sediments in various ways. Oil in the D-7 zone is undersaturated. At pressures above the bubble point, oil is recovered by the slight expansibility of the reservoir framework and its liquid contents. More than 40 pct as much oil probably will be recovered by this mechanism as will be recovered by internal gas drive after pressures pass below the bubble point. Operations are handicapped by sand and pipe troubles. Introduction The Ventura Avenue field has been under development since 1915. It has long been considered a "high-pressure" field, but interest was heightened by the extreme conditions encountered in the recent development of the so-called D-7 zone. The original reservoir pressure in this pool is estimated to have been 8300 psi at a depth of 9000 ft below sea level, or 9200± ft below the surface. A fluid pressure approaching that exerted by the overlying sediments has been encountered in other parts of the world, but never before in California to the degree observed in the D-7 pool. With few exceptions, the original pressure in California fields is about equivalent to the static head of water below the water table in the outcrop. Structure The Ventura anticline is a prominent feature of the Ventura basin, being traceable on the surface about 17 miles.' The Ventura Avenue field is at the apex of the anticline. It is about one mile wide and five miles long, the major axis lying in an east-west direction. The productive limits cover an area of about 2300 acres. The entire anticline has been severely folded and faulted. The productive portions in particular are broken up by three major thrust faults having a general east-west strike. The resultant four fault blocks are termed the A, B, C, and D blocks, respectively. Certain electric-log intervals are assigned numbers. Fig I is a diagrammatic north-south section of the field near the crest, looking west, and shows three of the four fault blocks. To the west, the upper fault divides into two branches, which define the B block. Wells penetrating a fault may duplicate over 1000 ft of formation. However, the greater fault movement is the strike shift, which is believed to exceed 2500 ft both between the A and C blocks and between the C and D blocks. The location of water is irregular and unpredictable. A few intermediate waters exist, while some strata have more than 2000 ft of productive closure.

Jan 1, 1948

By E. V. Watts

The D-7 zone of the Ventura Avenue field is of special interest because the initial reservoir pressure at 92.00 ft nearly equaled the pressure exerted by the overburden. While the phenomenon has been observed elsewhere in the world, there is no record of a previous case in California. Such high pressures have been attributed to sealing of the reservoir, followed either by emergence of the beds or by compaction of the sediments in various ways. Oil in the D-7 zone is undersaturated. At pressures above the bubble point, oil is recovered by the slight expansibility of the reservoir framework and its liquid contents. More than 40 pct as much oil probably will be recovered by this mechanism as will be recovered by internal gas drive after pressures pass below the bubble point. Operations are handicapped by sand and pipe troubles. Introduction The Ventura Avenue field has been under development since 1915. It has long been considered a "high-pressure" field, but interest was heightened by the extreme conditions encountered in the recent development of the so-called D-7 zone. The original reservoir pressure in this pool is estimated to have been 8300 psi at a depth of 9000 ft below sea level, or 9200± ft below the surface. A fluid pressure approaching that exerted by the overlying sediments has been encountered in other parts of the world, but never before in California to the degree observed in the D-7 pool. With few exceptions, the original pressure in California fields is about equivalent to the static head of water below the water table in the outcrop. Structure The Ventura anticline is a prominent feature of the Ventura basin, being traceable on the surface about 17 miles.' The Ventura Avenue field is at the apex of the anticline. It is about one mile wide and five miles long, the major axis lying in an east-west direction. The productive limits cover an area of about 2300 acres. The entire anticline has been severely folded and faulted. The productive portions in particular are broken up by three major thrust faults having a general east-west strike. The resultant four fault blocks are termed the A, B, C, and D blocks, respectively. Certain electric-log intervals are assigned numbers. Fig I is a diagrammatic north-south section of the field near the crest, looking west, and shows three of the four fault blocks. To the west, the upper fault divides into two branches, which define the B block. Wells penetrating a fault may duplicate over 1000 ft of formation. However, the greater fault movement is the strike shift, which is believed to exceed 2500 ft both between the A and C blocks and between the C and D blocks. The location of water is irregular and unpredictable. A few intermediate waters exist, while some strata have more than 2000 ft of productive closure.

Jan 1, 1948

By W. S. Sanner

Experiments were conducted to determine the quantity and purity of ultraclean anthracite that could be prepared in the laboratory, using conventional separating techniques. A low, a medium, and a high-volatile anthracite were studied. Specific gravity separation followed by grinding, screening, and refloating at lighter specific gravities yielded small quantities of material purified to 1.0% ash, as follows: from low-volatile anthracite, 0.7%; from medium-volatile coal, 1.0%; and from high-volatile coal, 2.3%. The reduction in ash had no appreciable effect on the volatile matter or sulfur content of the coal. The limited quantities of material containing 1.0% or less ash obtainable indicate that if ultraclean coal is desired, a practical approach should include the processing units as an integral part of a convc.ntiona1 dense-media washing plant. Anthracite preparation practices during much of the industry's history were geared to maximum recovery of the larger sizes, pea through egg, which were used in hand-fired, domestic furnaces. Those sizes were cleaned to meet trade requirements, and the smaller sizes were usually higher in ash content. The impression, thus, was that ash content of anthracite always increased as the sizes got smaller. It was presumed that it was impossible to wash the finer sizes to extremely low ash contents. Following World War 11, the classical domestic market began to decline and the finer sizes assumed an increasingly large share of the market. For example, in 1949l 61% of the production was still pea and larger. Fig. l2 shows that -by 1955 these sizes accounted for only 50%, and in 1965, they were only 39% of the total anthracite produced. With the reduction in the market, increased quality was demanded, especially in export markets, and an increasing number of dense-media magnetite washers were installed in new and existing cleaning plants. In 1965, the coarse coal prepared at 59 breakers in the anthracite fields was sampled by the U.S. Bureau of Mines (USBM); approximately 50% of these plants were equipped with dense-media magnetite washers.3 Since 1950, more attention has been focused on the use of finer sizes for numerous industrial uses, including iron-ore sintering, pelletizing, foundry coke-making, cement manufacture, production of calcium carbide, and of carbon electrodes, etc. Most industrial uses require relatively clean anthracite, such as 10 to 11% ash for sintering and foundry coke, 7% for aluminum melting-pot cathode carbon, and 5% for carbide production. Hence, cleaning methods have been improved to the extent that dense-media washers, hydraulic cyclones, and flotation cells have been introduced as fine-coal-cleaning devices. It is now possible to wash the buckwheat, rice, and barley sizes (9116 X 3132-in.) to ash contents as low as 8 to 10% in dense-media devices, but washing the -3132-in. sizes to those limits presents more difficult problems, due mainly to the fineness of the material. This USBM investigation was conducted to determine the amount and purity of ultraclean anthracite that could be prepared in the laboratory, using conventional separating techniques. The goal was to reduce the ash content to a level acceptable for industrial carbon uses, including electrode manufacture, which generally requires an ash content of 1% or less. While low-ash content is of primary importance in selecting industrial carbons, the amounts of other constituents are also important, including iron, silicon, titanium, nickel, vanadium, and sulfur. They were not considered in this work, since their occurrence in deashed anthracite has been studied elsewhere.4 The results of the present investigation were used to design a flowsheet, suggesting a method for producing ultraclean anthracite as part of conventional preparation practice, using dense-media vessels, crushers, pulverizers,

Jan 1, 1970

By O. K. Miniato, L. Massé, K. Nobe, J. S. Aronofsky, W. F. 213-000-000-016 Seyer

MUCH work has been done dealing with the effect of mechanical stress on electrode potential in an electrochemical system. The contradictory nature of the experimental results indicates the complexity of the problem although thermodynamic considerations show that a simple relationshir, should exist. In those systems where a gas was the electromotive active substance satisfactory agreement between theory and practice has been found. Des Coudres' found this to be so even when the active substance of the electrode, in this case mercury, was in the liquid state. In contrast, attempts to correlate theory and experiment for the solid state have met with a very limited success. The early workers in this field, Andrews,2 Walker and Dill3 used iron, certainly one of the most reactive of metals. Others have made use of less active metals such as copper and nickel. Recently Fryxell and Nachtrieb4 investigated the electrochemical behavior of gold and silver under both tensile and compressive stresses and concluded that it was doubtful whether true stress potentials could ever be measured. Much of the lack of success to measure the thermodynamic stress potential can be ascribed to the presence or formation of a complex film on the metal surface in contact with the electrolyte. Further, the theoretical stress potential is very small and therefore difficult to measure directly. Thus the calculated emf between a 24 B & S gage cold-drawn copper wire stressed with a weight of 1 kg and an unstressed portion of the same wire is only 2.60 X 10"7 volts. This is very small compared to that which can be produced by chemical reactions at the metal electrolyte interface which in turn can be so large as to mask completely the stress potential. Hence in this type of measurement all chemical side effects must be eliminated or reduced as much as possible. It was for this reason that the system copper-sodium chloride solution was selected for study. INSTRUMENTATION In the many preliminary experiments conducted, two major difficulties were encountered. The first was to measure the small electro-potentials to be expected and the second to obtain a suitable electrode surface. The conventional potentiometric method was found to be unsatisfactory for measuring the small emf expected. However, by using an L & N No. 2290 galvanometer having a resistance of 915 ohms consistent measurements were possible. The reference electrode was always the unstressed one made from the same sample of wire. The steady current flow was approximately 10-8 amp. Lewis and Randell5 have stated that for currents of the order of 10-8, if there is no sensible polarization, the measured emf may be taken as a reversible one. To check the galvanomenter readings an alternative method was devised to measure the potential difference between the wires. This involved a Liston-Falb d-c breaker amplifier model 10, an L & N k-2 potentiometer and a moving-coil galvanometer having a sensitivity greater than 0.1 µv (microvolt) per mm. To increase further the output voltage of the amplifier a d-c amplifier, model B. L.-932 was introduced into the circuit. This amplifier was in turn connected to a Brush recorder which had been calibrated previously by the test signals from the Liston-Falb instrument. These test voltages employed took into account the impedance of the input current. Unfortunately, this method had too low a sensitivity for measurement below 10 µv. Above this value the voltage agreed reasonably well with those obtained directly by the simple galvanometer method. The main advantage of the amplifier setup was that one did not have to wait until no deflection occurred on the galvanometer in the circuit when first exposing the wires to the solu-

Jan 1, 1959

By C.F. Pascoe, H.J. Roast

The object of this investigation was to compare the arsenical antimony-lead alloy with some of the regular bearing-metal alloys. With this end in view, the following tests were made: 1. Chemical analyses to show the composition. 2. Thermal analyses. 3. Macroscopic examination of fractures. 4.Microscopic examination. 5. Tensile tests. 6. Crushing tests. 7. Scleroscope tests.' 8. Brinell tests, at temperatures from 80' to 400' F. Tests 3 to 8 were conducted on both sand-cast and chill-cast specimens. For the purposes of this paper the alloys have been numbered from 1 to 6; their composition is as follows: Lead. ' Antimony, Tin, CoppeR ARSEnic, NumBeR PeR CENT. PER CENT. PeR Cent. PeR CeNt. PeR Cent. 1 82.64 12.95 4.40 0.01 none 2 27.54 9.04 59.87 2.65 none I 3 none- 0.13 ------------1.47 4 82.95 16.85 none 0.20 none 5 83.78 15.35 none 0.05 0.82 6 0.15 7.87 . 84.13 7.85 none The analysis, in the case of the antimony, was made by solution in sul-furic acid and titrated with permanganate. For tin, the ferric-chloride method was used; for copper, the alkaline separations, and the thio-cyanate methods; for arsenic, volatilization of arsenic and titration with iodine. The lead, with the exception of alloy 6, was taken by difference. With the exception of No. 5, the alloys were taken as received from the manufacturer. About 40 lb, were melted in a graphite crucible and recast into small ingots to insure uniformity of composition; samples

Jan 1, 1923

By C. F. Pascoe, H. J. Roast

The object of this investigation was to compare the arsenical antimony-lead alloy with some of the regular bearing-metal alloys. With this end in view, the following tests were made: 1. Chemical analyses to show the composition. 2. Thermal analyses. 3. Macroscopic examination of fractures. 4.Microscopic examination. 5. Tensile tests. 6. Crushing tests. 7. Scleroscope tests.' 8. Brinell tests, at temperatures from 80' to 400' F. Tests 3 to 8 were conducted on both sand-cast and chill-cast specimens. For the purposes of this paper the alloys have been numbered from 1 to 6; their composition is as follows: Lead. ' Antimony, Tin, CoppeR ARSEnic, NumBeR PeR CENT. PER CENT. PeR Cent. PeR CeNt. PeR Cent. 1 82.64 12.95 4.40 0.01 none 2 27.54 9.04 59.87 2.65 none I 3 none- 0.13 ------------1.47 4 82.95 16.85 none 0.20 none 5 83.78 15.35 none 0.05 0.82 6 0.15 7.87 . 84.13 7.85 none The analysis, in the case of the antimony, was made by solution in sul-furic acid and titrated with permanganate. For tin, the ferric-chloride method was used; for copper, the alkaline separations, and the thio-cyanate methods; for arsenic, volatilization of arsenic and titration with iodine. The lead, with the exception of alloy 6, was taken by difference. With the exception of No. 5, the alloys were taken as received from the manufacturer. About 40 lb, were melted in a graphite crucible and recast into small ingots to insure uniformity of composition; samples

Jan 1, 1923

By Hewitt Wilson

IN 1903, T. M. and E. H. Alvord, of Marblemount, Wash., built a soapstone-grinding mill in the Skagit River Valley and are reported to have produced "ground talc" during 1904 and 1905, shipping to the paper mills in Wisconsin. Between 1916 and 1920, the Western Talc Co. built and operated a talc-grinding mill north of Mondovi, on the banks of the Spokane River, in eastern Washington, and sold powdered talc to the Inland Empire Paper Co. of Spokane. ? The most active develop-ment in recent years has been by two companies in the Skagit Valley-the Skagit Talc Company, Inc., which has been sawing soapstone block for the soda-recovery furnaces of the pulp and paper companies, and the Asbestos-Talc Products of Washington, Inc., at Burlington, which has been mining and dry-grinding a soft serpentine for the structural filler and insulation trade. Many prospects have been opened in the northern part of the state on both sides of the Cascade Mountains, and these activities undoubtedly are the forerunner of an industry that promises to attain considerable magnitude in the North Pacific States. At the present time, talc is imported from California for use as paper filler, and soapstone block from Virginia for use in the soda-recovery furnaces. A small market has been created locally for tailor and foundry:, pencils, stove grills, and block soapstone for art objects. The results of the present study, as yet incomplete, indicate that the use as a refractory and as a ceramic filler and flux can be expanded.

Jan 1, 1936

By T. N. Dixon, J. E. Briggs

A study was made of numerical techniques for solving the large sets of simultaneous equations that arise in the mathematical mode ling of oil reservoir behavior. It was found that noniterative techniques, such as the Alternating Direction Implicit (ADI) method, as well as some other finite difference approximations, produce oscillatory or unsmooth results for large time steps. Estimates of time step sizes sufficient to avoid such behavior are given. A comparison was made of the Point Successive Over-Relaxation (PSOR), Two-Line Cyclic Chebyshev Semi-Iterative SOR (2LCC), and iterative ADI methods, with respect to speed of solution of a test problem. It was found that, when applicable, iterative ADI is fastest for problems involving many points, while 2LCC is preferable for smaller problems. INTRODUCTION With the advent of high speed, large memory, digital computers, there has been an increasing emphasis on the development of improved methods for simulating and predicting reservoir performance. Two-dimensional, three-phase reservoir models with various combinations of PVT effects, as well as gravity and capillary forces, are common throughout the industry. Such models are also available through consulting firms, to anyone desiring to use them. Three-dimensional models will probably be practical in only a few years. We conducted a study of some of the numerical methods used for solving the large sets of simultaneous equations that arise in such models. A typical set of equations for a reservoir model is shown below:

Jan 1, 1969

By Benjamin F. Tillson

THE past seven years, and 1937 in particular, have witnessed the return of New Jersey iron mining to a place of importance. Following the World War period, little mining was done for several reasons. The properties were operated by small merchant furnaces whose demand was not sufficiently large to warrant large-scale methods with their attendant low operating costs. Under those conditions, the ore produced could not compete with that from the Great Lakes. However, when on Nov. 1, 1.929, the Alan Wood Steel Co., of Conshohocken, Pa., leased the Scrub Oak and Washington properties at Mine Hill and Oxford respectively, they made radical changes in the mining and milling processes which greatly reduced the cost of production and pointed the way to a renewed interest in mining in New Jersey. The following factors have been advanced as influencing the reopening of New Jersey mines:

Jan 1, 1938