Search Documents

By A. M. Nicholas

WHEN attempting to lift mill pulp containing a considerable percentage of wolframite, in an ordinary bucket elevator, difficulty was encountered from the tendency of the tungsten minerals to settle, on account of their high specific gravity. Lifts not exceeding 20 ft. (6m.) could be accomplished without particular difficulty, because there was insufficient time for consolidation of the heavy minerals in the bottom of the bucket; but with higher lifts, the heavy tungsten minerals would settle so solidly that when the bucket turned over at the top of the elevator the contents could be only partially dumped. In this case it ,was necessary to lift the material a distance of 34 ft. (10m.); hence some means had to be adopted to prevent settling, at least to such an extent that the material could be dumped from the buckets. To reduce the carrying time to a sufficient extent would have required a belt speed of 475 ft. (144.7m.) per minute, which was not feasible. It was decided to try, by vibrating the belt about midway of its span, to keel) the material sufficiently agitated during elevation to prevent settling. Underneath the rising side of the belt was placed a 12-in. (30.48-cm.) idler pulley, 18 ft.-(5.5 in.) up in the total lift of 34 ft. The idler pulley was set eccentric by 3/4 in. (19 mm.) and it was hoped that the vibration thus imparted to the belt, running at a speed of 280 ft. (85 m.) per minute, would prevent settling in the buckets. It was found that the pressure of the belt on the idler, due to the small inclination of the elevator, was not sufficient to overcome sliding on the idler, and the agitation was insufficient to accomplish the desired purpose. The idler was then connected to the drive shaft of the elevator through an intermediate pulley, gearing down to a speed of 20 r.p.m., so that a positive vibration was imparted to the belt; this imparted enough motion to the belt to prevent settling and the contents of buckets clumped satisfactorily.

Jan 2, 1918

By J. O. Nomland

DuRing the year 1939 the program of the California Arabian Standard Oil Co. in eastern Saudi Arabia consisted of drilling wells to increase the production of Dammam Dome. (This structure is also sometimes referred to as Dhahran Dome.) In addition, in other areas of the concession, wildcat wells are being drilled on geologically favorable structures. In the early wells drilled at Dhahran, production was at a depth of 2000 to 2200 ft. Since discovery of the "Arab zone" below 4300 ft., all of the later wells have been drilled to the deeper productive members. At present there are at Dhahran fivc wells in various stages of drilling or completion. In addition, 15 wells previously were drilled to the upper or lower zones. Although some of the early locations are exceptions, in general the spacing of the wells is at 3000 feet. Prospect testing consisted in drilling one well at Abu Hadriya and one at Ma'agala, about 100 miles northwest and 120 miles west of Dhahran. The first had attained a depth of 8655 ft. without encountering the main Darnmam productive zone, while the second was at a depth of 1372 ft. Both of these wildcat wells are on large dome structures. Production.—During the year 3,933,903 bbl. of approximately 35" gravity oil was produced, all from flowing wells. A part of this production was shipped in barges to the refinery at Bahrein. In early May a 40-mile 10-in. pipe line was completed to the deep-water terminal at Ras Tanura. The ceremony of first opening the valve for flow of oil into an ocean tanker was performed by King Abdulaziz Ibn Saud. Since that time tanker shipments have continued, both to Bahrein and to world markets. Only sufficient gas for camp purposes has been produced. Equipment.—A stabilization plant has been completed at Dhahran and plans have been made for a refinery at Ras Tanura. A modern camp is being built including power plant, central air-conditioning plant, radio station, employees' club and housing facilities for both married and single employees. Both the offices and dwellings are being air-conditioned. There is a hospital, with medical staff and nurses, providing facilities for both Saudi Arabs and Americans.

Jan 1, 1940

By Ronald Gibala

THE Au-Ni alloy system is one of many binary systems in which the supersaturated solid solutions may exhibit a multistaged precipitation behavior during aging. In addition to the equilibrium phase separation, which was studied extensively years ago in the range 400" to 600",' there exists at least one earlier stage of precipitation, i.e., preprecipitation, which occurs below 300°C in quenched alls.-This note reports on some effects of composition on the preprecipitation in Au-Ni alloys as determined from resistivity measurements. The kinetics of the preprecipitation were studied in alloys of 15 to 85 at. pct Ni which were water- were found in alloys which after various quenching-and-aging treatments were slowly heated and cooled (1Z"C per hr) between room temperature and about 300°C. Two such heating-cooling curves for a 40 pct Ni alloy are shown in Fig. 2. Similar effects were observed in other 15 to 50 pct Ni alloys. These curves are characterized upon heating by two changes in slope indicated by A and B in the figure and upon cooling by a resistivity hysteresis of approximately the size of the original decrease in resistivity after the aging treatment. The inflection at B generally falls at about the same temperature for all heating curves for a given alloy and appears to be a critical temperature (T,) for the preprecipitation for that alloy. The values of T, for most of the 15 to 50 pct Ni alloys fall in the range 200" to 220°C. The position of the inflection at A depends upon the heat treatment prior to the heating-cooling run and perhaps the heating rate, which was held constant in these runs. The preprecipitates grown in by the appropriate aging treatments seem to decrease in size as the alloys are heated from A to T,, dissolve at T,, and do not reappear after cooling below T,. When similar heating-cooling treatments were performed on 60 to 85 pct Ni alloys, an entirely different behavior was observed. Typical results are shown in Fig. 3 for an 85 pct Ni alloy. In these

Jan 1, 1964

By C. A. Edwards

Following a brief introduction, an outline is given of the four main conditions in which gases may be associated with metals; namely, (1) adsorbed gases, (2) dissolved gases, (3) gases in chemical combination, (4) gases entrapped in blowholes or cavities. Adsorption is essentially a surface phenomenon and is regarded as the attachment of outside molecules or atoms to the exposed free valencies of the atoms comprising the surface layers. In many cases where adsorbed films of gas are formed this is accompanied by a process of diffusion of the gas into the metal itself. This is particularly true in respect to iron and hydrogen, and experiments have shown that there is no difference between the rate at which hydrogen diffuses through a single crystal of iron arid through the same material after it has been recrystal-lized into a mass of small crystals. This does not prevent a somewhat greater concentration of gas at the boundaries of adjacent crystals, nor does it mean that the effect of the gas will be the same at the boundaries as it is within the body of the crystals. Indeed, under certain conditions, iron is rendered very brittle at the crystal boundaries, as shown in experiments by Pfeil with samples of almost pure iron. Much work has been done by many investigators concerning the temperature and conditions under which dissolved hydrogen, in particular, can be at least partially removed from different metals. With iron, the hydrogen that has diffused into the metal as a result of acid attack by pickling or by electrolytic deposition of the gas on the metal is partly removed by exposing the metal to the atmosphere at ordinary temperatures. Considerably more can be eliminated by raising the temperature, and even greater quantities by jointly raising the temperature and reducing the pressure. Annealing at suitable temperatures completely removes the bad effects of excessive mounts of hydrogen dissolved in or associated with iron. This is shown by the data plotted in Fig. 1, giving values for electrolytic iron sheets after annealing at temperatures between 250" and 950" C. The hydrogen brittleness is rapidly diminished at

Jan 1, 1935

F. JOHNSON,* Birmingham, England (written discussion t).--. Mr. Skowronski's first melting experiments tend to show that ingots with a "level set" may be obtained without oxygen. Now it is characteristic of all metals which occupy a smaller volume when solid than they do when molten to "pipe." In vertical-cast ingots, this pipe resembles a horn-shaped cavity, with the wide mouth uppermost. In horizontal-cast ingots, the pipe is a longitudinal furrow along the center-line of the ingot surface. If copper be successfully deoxidized and degasified, this furrow will inevitably be produced. In the author's oxygen-free ingots, it is. clear that gases were occluded and these gases effectively opposed the formation of a pipe or furrow by shrinkage (fluid contraction). It is riot a special property of any particular gas which produces this effect. Hence it is not surprising that the author has succeeded in producing level and overpoled ingots through the agency of sulphur. dioxide gas. That he has counteracted the overpoling influence of sulphur by means of oxygen is somewhat difficult to explain, since the well known reaction between cuprous sulphide and cuprous oxide should result in the production of sulphur dioxide gas. Why the presence of excess cuprous oxide should neutralize the overpoling influence of this gas without eliminating sulphur is not at all clear. It is to be regretted that the oxygen was not determined in the bars given in Tables 3 and 4. It is by no means established that sulphur is responsible for the over, poling of ingots given in Table 4, since carbon was used for overpoling. If, however, the same kind of poling treatment was given as that applied in the case of ingots in Table 1, the responsibility of sulphur assumes more definite shape. The author rightly points out that Mr. Johnson's theory of the equilibrium between gases and cuprous oxide does not explain why a simple addition of cuprous oxide does not correct an overpoled charge. Such a charge must be re-worked to "set" copper. This re-working (rabbling) undoubtedly forcibly removes the excess gases, which are not removable by cuprous oxide.

Jan 11, 1918

By C. J. Delisio

The basic concept of tunnel boring has not changed since the late 1800's. R. Stanley of Great Britain obtained a Canadian patent as early as December 1891. Mr. Stanley's machine was a device that consisted of a rotating wheel equipped with drag-type teeth; it had a means of thrusting the cutterhead against the face or heading; it had a means of clamping or gripping the machine in its bore; it had a means of collecting and depositing the cuttings into a screw-type conveyor located near the invert of the tunnel. It even had a means of varying the speed of the forward motion of the machine to suit different hardnesses of rock encountered. This description essentially fits the latest tunnel-boring machines being built today. In short, there has been no significant advance in the basic concept in 70 to 80 years. It may well be that no significant change can be expected for some time into the future. Today's machines, while still basic in concept, offer many advances aimed at faster tunneling. Among these are 1 ) improved cutters, 2) guidance and steering devices, 3) dust-control devices, and 4) mechanisms to aid in installing tunnel supports. CUTTERS The most important part of a hard-rock tunnel borer is the cutter. If the cutter can cut the rock, it is a boring machine. If the cutter cannot cut the rock, no other part of the machine can. When Jarva, Inc. decided to build a machine, the first problem was to find a good cutter. In our search, we looked at most of the cutters on the market. We selected Reed Drilling Tools' cutter because the design of their cutter was aimed at hard-rock tunneling. We feel that they build the best cutter available and provide the best possible service to their customers. As tunnel-boring machine design advanced, the transition from drag bits to roller bits was natural because harder formations required a roller bit, and it is the goal of all mole users to bore harder formations. Roller bits

Jan 1, 1970

By F. C. Sturges

By definition the word "grout" means a thin mortar, or a kind of plaster or cement, and "grouting" means to fill up or finish with grout. The words "cement," "plaster" and "mortar" mean a substance that is used in a soft state which subsequently hardens. Thus, grouting is the filling of void space with a substance that hardens. Construction cements are the most common substances used, either by themselves or in mixtures, but the term grouting is applied quite correctly when other substances such as plastics and certain chemicals are used. Also, the use of the term grouting to cover the filling of voids with materials that do not actually become hard, such as the flotation tailings used in grouting in the southeast Missouri lead district, should be considered correct, as some stiffening does take place and, anyway, it is a better descriptive term than any substitute. Engineers are interested in grouting because some of the materials with which they must work contain voids, and certain conditions can be improved if these voids can be filled with something solid and permanent. Grouting is done to accomplish several purposes: I. To stop the passage of fluids and gases, 2. To cement materials together to make them stronger, and 3. To prevent consolidation of materials by filling void space with something solid as a replacement for the air and water that could be forced out under load. The construction industry uses grouting extensively for all three purposes. Grouting is used to stop water percolation under and around dams. It is used to control water flow in tunnel driving and in shaft sinking. It is used to improve foundation conditions under civil engineering structures by permanently filling void space and thereby reducing settlement, or by cementing broken rock together and increasing its supporting strength. The oil and gas industry does a lot of grouting, primarily to stop the passage of gases and fluids. The search for oil at increasingly greater depths has meant greater investment per well, and the oil industry has spent large sums on development of improved drilling methods. This

Jan 1, 1949

By Albert F. Schneider

The peculiar conditions under which lead and silver ores are now smelted in Salt Lake Valley, Utah, render it advantageous to make slags that are siliceous and carry a high percentage of lime. The ores treated come from Utah, Idaho, Montana, and Nevada; nine-tenths coming from Utah. These ores are siliceous, and contain but little fluxing material; the iron present scarcely sufficing for the sulphur and arsenic. Formerly ores high in iron were furnished from Cottonwood Canons, but this supply is meagre. The ores from Idaho, Montana, and Nevada are high grade galenas, more or less impure. They generally require a large amount of iron for the sulphur, arsenic, and antimony. In the winter and spring of 1880—'81, we were treating at the Germania Works principally Bingham Canon lead ores and silver ores from Tintic. The former contained 15 to 30 per cent. silica, and only 4 to 5 per cent. iron (generally as iron pyrites); they ranged high in lead and low in silver, and carried more or less alumina; the lead was present chiefly as carbonate. The silver ores from Tintic contained sulphides, and ran as high as 80 per cent. silica. We had been running on a slag approximating 40 per cent. FeO, 20 per cent. CaO, 10 per cent. other bases, and 30 per cent. SiO2, which had heretofore been very satisfactory; but with the class of ores then coming in it was of the utmost advantage to use less iron and more lime, especially as the iron ore (50-55 per cent. iron and 5-7 per cent. silica) cost four times as much as the limestone (50-55 per cent. lime, 3-5 per cent. silica). The large amount of alumina in the slag influenced them for the worse; the addition of lime to the charge helped them, and after many experiments regarding the proportion of FeO, CaO, and SiO2, a slag approximating 35 per cent. FeO, 25 per cent. CaO, 5 per cent. other bases, and 35 per cent. SiO2 seemed to answer

Jan 1, 1883

By W. D. Bennett

AN interesting effect has been observed in the vacuum etching of titanium in the high temperature ß phase. Using a high vacuum annealing furnace, operating at less than 2x10-6 mm with a tubular titanium liner, it has been found possible to etch polished metallographic specimens at different temperatures between room temperature and 1000°C without contamination or increase in hardness.' Heat etching of titanium has been reported by other workers,' but the following example is of interest as an experiment under high vacuum in the absence of any contamination. Two polished specimens of iodide-processed titanium are placed at different positions along the axis of the furnace corresponding to temperatures of 900" and 800°C above and below the a-ß transus. The specimens are then raised to these temperatures and annealed simultaneously for 3 hr under the same high vacuum conditions. After cooling and withdrawing the specimens, their surfaces are photographed without further treatment. Figs. 1 and 2 show the results for the 800" and 900°C specimens, respectively. Fig. 1, corresponding to a vacuum etch in the a region, shows a typical equiaxed structure with what appears to be a slight shift of grain boundaries. Fig. 2, corresponding to a vacuum etch in the ß region, shows an equiaxed type of structure with the growth of striations in certain grains. The striations are only superficial, as a light polish and chemical etch restores the clean equiaxed structure. The vacuum etch, occurring as it does above the a-ß transus, records the state of the metal in the ß phase by means of the surface relief produced by the selective evaporation of metal from different grains; the metal itself reverts to the equiaxed a on cooling. The nature of the ß etch" (Fig. 2) suggests that, in transforming from the close-packed-hexagonal a to the body-centered-cubic ß lenticular-shaped laminae are formed parallel to common planes of the two structures. This would explain why some grains appear to be unaffected by the etch. The technique has interesting possibilities in the investigation of the mechanics of high temperature transformation. Acknowledgment This note is published by permission of the Deputy Minister, Dept. of Mines and Technical Surveys, Ottawa, Ont., Canada.

Jan 1, 1956

By C. R. Breck

THERE has been a running discussion over the-past several years with respect to the life and adequacy of our natural gas reserves.. Some of the experts agree on one phase of the subject at least--that eventually it will be necessary to augment deliveries of natural gas in the northern markets by the development of a more or less comparable synthetic gas made from coal. The purpose of this paper is to point out: 1. It may be later than a good many people think-the demand for additional domestic and commercial pipeline gas in at least one section of the North will probably be felt rather keenly before an adequate synthetic pipeline-gas project, developed on economic lines, could be completed, even if ' initiated in the near future. 2. The evidence is considerable that such a project would be technically sound and economically self-supporting, although the margin of profit at first might be so small and the magnitude of an economic enterprise so great that financing would be impossible without Government aid in some form or other. The part of the country referred to is the heavily populated section in the northeast of the United States. To simplify an examination of the situation, let us take the potential marketing areas within range to the north and east of the three pipelines: 1. Tennessee Gas Transmission Co. as it enters Erie County, New York state. 2. Texas Eastern Transmission Corporation just before the tap that supplies the general Philadelphia area. 3. Transcontinental G& Pipe Line Corporation as it enters the state of New Jersey The sources of gas for these three pipelines are in Texas and Louisiana. The ultimate maximum combined capacity of the three lines at the points stated is approximately 1,200,000,000 cu ft per 24 hr at the maximum load factor probable of attainment in normal operation. The areas supplied by the three lines north and east of the points stated, or assumed as eventual markets, are: 1. Central New York state, from Buffalo to Albany (both inclusive).

Jan 1, 1953

By Geoffrey Purcell

For anyone contemplating flotation research with only a very limited amount of mineral available for testing, the choice of suitable experimental equipment is by no means obvious. Hallimond's original and delightfully simple cell1 has been modified by subsequent investigators2to give quantitative and reproducible results on small samples. However, the modifications have necessarily compromised its simplicity, and the services of a skilled glass blower are required to duplicate the cell. Vacuum flotation tests3 at best qualitative and may, under certain conditions4, be quite impracticable. A hundred years ago, Thoreau observed that "our life is frittered away by detail," and his advice was to "simplify, simplify," The success of the simple cell described below, which was developed by the author and differs somewhat from Hallimond's original, suggests that Thoreau's advice still has merit a century later. CELL CONSTRUCTION The cell [Fig. 1 (a) and 1 (b)] consists essentially of a 25-ml pipet from which has been cut the con- stricted top. The length cut off is not critical since this merely determines the final volume of the cell. Cell volume may be varied in this way from 20 to 50 cc. A pyrex extension tube, equal in diameter and approximately half the length of the cut pipet, is attached to the top of the pipet by means of 2 ½ in. of close-fitting tygon tubing. When assembled, the two pyrex tubes should be spaced about ½ in. apart. Another length of tygon tubing is added to the extension piece for sealing purposes. A ¾ -in. disc of porous material (teflon cloth is ideal), secured in place over the pipet tip with another piece of shaped tygon tubing, completes the cell assembly. Tygon tubing may be shaped by pushing it over the pipet tip or some similar form and heating carefully over a low flame. For flotation [Fig. 1 (c) 1, the pyrex extension tube is rotated approximately 70º from the vertical and held in position by a wire hook and eye. Floated material, after reaching the free surface, falls and rests on this inclined plane. The barrier formed by the bent tygon tubing ensures that floated material does not slide back and return to the vertical portion of the cell.

Jan 11, 1965

By F. N. Speller

Interest in the corrosion problem seems to continue without abatement and is bringing practical results. At least four important conferences on this subject have been held during the last 5 months. Those interested in steel-frame structures are taking steps to study vulnerable points on account of the failure of some minor parts in certain buildings after 35 years of service. The steam power-plant group, including the railroads, realize the importance of a better knowledge of corrosion, especially under modern high-temperature boiler operations. The chemical and refrigerating industries have already conducted a systematic study of depreciation of metals by corrosion, for which they have spent considerable money and time during the last 2 years with encouraging results. More has probably been done to control corrosion in the atmosphere and in closed water systems, because the work on these phases of the problem started over 15 years ago and the important factors are now fairly well understood. As a result of all this work, there is now little excuse for corrosion in water conduits, recirculating condensers and cooling systems, since economical means of prevention have been worked out to meet nearly all situations where such corrosion occurs. The entire Baltimore water supply was treated with lime at a cost of only 35 c. per million gallons and the rate of attack on the pipes has been reduced to not over 20 per cent. of what it was before the treatment. Yearly damage to water mains in Baltimore is estimated at $300,000, and in New York City at $5,000,000, not including damage to water conduits in buildings. In some cities corrosion is now recognized by water works' engineers as a major problem. In the oil industry, there are evidently three general classes of corrosion, relating to: (I) Production, (2) transportation, and (3) refining. (1) Production.—Some fields, those of California for example, have little corrosion trouble in the wells. In others this is a major problem and should be a strong incentive to the development of more resistant metals at a reasonable cost. E. G. Woodruff,' consulting geologist, has pointed out that more of the oil of the future will probably come from the

Jan 1, 1927

By M. E. Straumanis, S. M. Riad

The lattice parameter of 99.999 pct pure Ag rtlas redetevnzined and found to be az5 = 4.08626 5 0.000041 with the vefnzctiotz correction included); the expatzsion coejjicient between 10° and 65°C was 18.73 X10-6°C-1. The lattice paratneter increased upon solution indium in silver in good agrement with other authors. The solid-solubility limit around room temperature was at 20.4 wt pct of in, which suggests that the high-temperature solubility (at about 689°C) determined by other authors is too low. The expansion coejficient of si1ver increases with the itzcrease of indium content between 10° and 65° C from, 18.73 (In = 0) to 20.9 x 10-6°C-1 (In = 20.4 pct), being only very slightly influenced by small amounts of indium. The expansion coefficents of all solid solutions increarsed strongly with temperature, reaching values > 27 x 10- 6 800°C. ACCORDING to the Ag-In diagram,' the solubility of indium in silver (the a phase) extends to about 18 pct by weight at room temperature. However, there has been only one investigation of the solubility limit by X-ray methods—that of Weibke and Eggers.2 Hume-Rothery, Lewin, and Reynolds measured only the lattice parameters of Ag-In solid solutions3 as did Owen and Roberts4 and Adler and Wagner.' The thermal expansivity of four solid solutions was determined by Owen and Roberts4 in a temperature range between 25" and 300°C. In view of the limited amount of work on Ag-In solid solutions, it seemed appropriate to redeter-mine the lattice parameters and the room-temperature solid-solubility limit, to find the exact expansion coefficients of the solid solutions at about room temperature (between 10° and 60°C) and the expansivity up to 800°C, and finally to derive the thermal-expansion coefficients for any alloy within the solid-solubility region. THE ALLOYS AND THE DETERMINATION OF LATTICE CONSTANTS The metals used were 99.9991 pet pure, supplied by the ASARCO company. Both silver and indium were weighed accurately on an analytical balance in

Jan 1, 1965

By Nelson W. Taylor

With the extensive deposits of potash minerals which have been discovered in the southwestern states, and their rapid development, a permanent American supply of potassium compounds is now assured. The 325-year history of the potash industry in this country has been told by H. I. Smith1, of the U.S. Geological Survey, and the more recent activities of the Survey and of American potash companies were described last year by the same author2. In fact, it may be stated that so great is the productive capacity that two mines in New Mexico and one in California are able to supply more than half a million tons of crude and refined salts over and above that produced for agricultural purposes. The era of scarcity has given way to an era of superabundance. This situatiori makes it desirable for the potash producer to look for other applications for his product, and it is with this in mind that the writer presents some information pertaining to present and possible future uses for potassium compounds in the ceramic industry. Ceramic Products Ceramic products are essentially solid materials containing one or more oxides such as SiO2, Al2O3, CaO, MgO, FeO, K2O, Na2O, TiO2, which are the oxides of greatest abundance in the earth's crust. The typical ceramic process is that of firing or burning the batch, and the product may be glassy, crystalline or mixed. In the glassy or vitreous group come glass, porcelain enamel and glazes; in the crystalline group, refractory materials such as silica brick, or chromite or magnesia; and in the mixed group, porcelain, chinaware, stoneware, tile, brick, etc., which contain both a vitreous and a crystalline phase, in variable proportions. The ceramic industry of the United States is a billion dollar industry, and is important not only because of its magnitude but also because of the key position occupied by certain ceramic products in the whole manufacturing structure. From the standpoint of use of potash, the field of refractories is of no great interest, since K2O lowers the melting point of a refractory oxide and

Jan 1, 1938

By Nelson W. Taylor

With the extensive deposits of potash minerals which have been discovered in the southwestern states, and their rapid development, a permanent American supply of potassium compounds is now assured. The 325-year history of the potash industry in this country has been told by H. I. Smith1, of the U.S. Geological Survey, and the more recent activities of the Survey and of American potash companies were described last year by the same author2. In fact, it may be stated that so great is the productive capacity that two mines in New Mexico and one in California are able to supply more than half a million tons of crude and refined salts over and above that produced for agricultural purposes. The era of scarcity has given way to an era of superabundance. This situatiori makes it desirable for the potash producer to look for other applications for his product, and it is with this in mind that the writer presents some information pertaining to present and possible future uses for potassium compounds in the ceramic industry. Ceramic Products Ceramic products are essentially solid materials containing one or more oxides such as SiO2, Al2O3, CaO, MgO, FeO, K2O, Na2O, TiO2, which are the oxides of greatest abundance in the earth's crust. The typical ceramic process is that of firing or burning the batch, and the product may be glassy, crystalline or mixed. In the glassy or vitreous group come glass, porcelain enamel and glazes; in the crystalline group, refractory materials such as silica brick, or chromite or magnesia; and in the mixed group, porcelain, chinaware, stoneware, tile, brick, etc., which contain both a vitreous and a crystalline phase, in variable proportions. The ceramic industry of the United States is a billion dollar industry, and is important not only because of its magnitude but also because of the key position occupied by certain ceramic products in the whole manufacturing structure. From the standpoint of use of potash, the field of refractories is of no great interest, since K2O lowers the melting point of a refractory oxide and

Jan 1, 1938

By W. A. Backofen, N. E. Paton

DEFORMATION twinning contributes to the plasticity of titanium and has been reported on {10i2}, {1121},{11221}, {1123}, and {1124} planes.' Twinning on {1011} has also been reported in commercially pure titanium as a result of quenching from 1000', but no reports of such twins occurring as a result of deformation alone are known to the authors. In this study single crystals grown from iodide titanium were compressed parallel to the c axis over the temperature range 25 to 800°C. From it has come evidence that (10il) deformation twins are the most common type between 400" and 800°C. Crystals about 6 mm high with a rectangular cross section measuring about 3 by 4 mm were used in the tests. Chemical analyses showed them to contain 220 to 250 ppm 0 arid 10 to 15 ppm N. The long axes of the crystals were made parallel to the c axis while the sides were parallel to (i100) and (1120), as shown in Fig. 1. The crystals were compressed between polished alumina platens with no lubrication, in a vacuum of 2 x lom5 torr. Between 25' and 300°C the predominant twinning mode was (11221, which is to be expected for this stress state. There was an abrupt change at 400°C, however, and from that temperature up to 800°C twinning took place almost entirely on (10i1 ). Twin planes were determined by the two-surface rnethd. Measurement of the crystal orientation within several (10i1) twins by means of polarized-light4 and transmission electron microscopy showed that the lattice reorientations were the same as those previously reported for the (10i l ) twinning in magnesium.' This reorientation is consistent with The calculated (10il ) twinning shear for titanium is 0.10, while that measured from surface offsets on a (1150) face, which is parallel to the shear direction, was about 0.15. Slip within the twins, or in the matrix adjacent to the twins, probably accounts for the larger measurement. Slip in both locations was judged to have occurred from observations on foils in the electron microscope.

Jan 1, 1970

By C. T. Bischoff

This paper describes the results of testing with colorimetric methods, using "dithizone", soil samples taken over various known copper and zinc deposits covered by glacial till. Variation in results is shown for different depths and types of overburden as well as grade and type of deposit. Limiting factors for the practical application of this work are discussed. The method has proved successful for copper and zinc deposits under clay and fine sand with depths up to at least 30 ft but fails in coarse sand and gravel unless depths are very shallow. Swamps require penetration to the underlying subsoil for sample material. DURING the past few years geochemical testing for traces of heavy metals in water, soil, rock, and vegetation has aroused increasing interest. Various techniques for field and laboratory determinations have been described in the literature, as have some of the results of application. However, little information has been published regarding application to glacial terrain. Over 90 pct of the Canadian Shield is overburdened, resulting in high costs for mineral exploration once the outcropping ore deposits have been found. This has been largely responsible for the widespread application of mining geophysics in Canada, permitting concentration of effort on area or zones considered most favorable. However, geophysical interpretation has its limitations, since at least 90 pct of the structures indicated thereby contain no valuable minerals. A more direct approach is therefore highly desirable. If underlying base metal mineralization can be detected by sampling soil or vegetation at moderate cost this should prove of great help in locating new discoveries or extending known ones. A large proportion of Canadian ore deposits contain appreciable copper or zinc, even where these are not the principal economic metals. Consequently the field of application is a broad one. This paper deals with investigations along these lines with particular emphasis on soil sampling. The problems involved from the start were: 1—Which types of glacial soil, if any, would best lend themselves to testing, and conversely which types might be considered relatively hopeless? 2—Through what depths of overburden could significant mineralization be detected? 3—What sampling techniques would prove economically applicable? This included minimum depth of sample and maximum spacing that could be allowed.

Jan 1, 1955

By E. Miller, R. Geffken, K. L. Komarek

The thermodynamzc properties oJ liquid Cd-Sb alloys were investigated using the cell arrangement measurments were obtained every 2°C at a heating and cooling rate of 12°C per hr and at equilibrium every 2O0C frorn 500°C down through the stable liquidus. The S-shaped asCd US composition curve was used in the cotnposition regzon near Cd,Sb, to calculate a tempeerture-dependent inleraction coefficient from quasichemical theory. Rapid changes in a scd were observed at a transition temperature varying from 400" to 465°C depending on con/kosition. It could not be determined if the changes in aScd were discontinuous, but tlze composition dependeke of the magnitude of the change is indicative of a second-order phase transformation in the liquid. The values of the experimental changes in ASCd are in agreement with calculations from the slope of the transition temperature, using the concept that a second-ovdev phase transition occurs in liquid Cd-Sb alloys. II is suggested that the transformalion is associated with the formation of Cd4Sb3 molecules in the liquid. ThE structure of liquid alloys is the subject of many investigations. X-ray, resistivity, and thermody-namic data have been interpreted as indicating varying degrees of short-range order in the liquid in alloy systems forming inter metallic compounds. In general, the melting process is not a transition from an ordered to a completely disordered state, but some degree of order is retained in the liquid. Maximum ordering in the liquid state occurs close to the melting temperature of the compound and the arrangement of atoms becomes more random at higher temperatures. Of special interest in this respect is the Cd-Sb system. It is one of the few metallic systems which form both stable and metastable compounds when liquid alloys are cooled at normal rates. The stable system exhibits an intermetallic compound, CdSb, melting at 459"c.l A second compound, CdrSbs, has also been reported,' melting close to this temperature. The metastable system has one compound, CdsSbz, melting at 420"c.I Resistivity measurements on liquid Cd-Sb alloys close to the liquidus temperatures have been interpreted in terms of a complex ordering behavior which changes rapidly with increasing temperature.3 The resistivity-composition curve is characterized by two maxima corresponding in composition to CdSb and CdsSbz. The resistivity-temperature plots show sharp breaks for alloys in the composition range of 45 to 70 at. pct Cd on cooling through a transition temperature close to the stable liquidus. Fisher and phillips4 investigated the influence of temperature and composition on the viscosity of liquid CdSb alloys. The viscosity of some alloys increases sharply on supercooling below the stable liquidus. A maximum in the viscosity-composition curve occurs at the composition CdSb. The thermodynamic properties of liquid Cd-Sb alloys have been investigated by Seltz and ~e~itt' and Elliott and chipmane by the electromotive-force method and their results are in good agreement. However, these investigations were carried out at temperatures well above the liquidus temperatures of the alloys, and the temperature coefficients of the electromotive force, dE/dT, were obtained from experimental points for each alloy at a few temperatures considerably above the liquidus temperature. Scheil and ~aach' investigated the thermodynamic properties of this system by the dew point method in the temperature range from about 100°C above the stable liquidus down into the supercooled liquid region. They reported several anomalies, i.e., the activity of a melt on heating differed from that on cooling, and the activity increased sharply in the limited temperature interval immediately above the liquidus temperature of the stable alloy, followed by a sudden decrease below the liquidus. Values obtained on heating and cooling were not in agreement. A reinvesti-gation of a few alloys by Scheil and Kalkuhl' by the electromotive-force method failed to confirm these observations. The authors concluded that the anomalies were due to inhomogeneities in the starting alloys and they discarded their previous results. The present investigation was undertaken in order to obtain thermodynamic data close to the liquidus temperature and in the supercooled region where the anomalies were originally reported, employing the electro motive-force method. This method is quite precise and will most easily permit observations of small changes in activity and partial molar entropy with temperature. Measurements were taken every few degrees so that the dE/dT values could be calculated over the entire temperature range and small changes in the thermodynamic properties close to the liquidus temperature could be observed. I) EXPERIMENTAL PROCEDURE Specimens were prepared from 99.999+ pct Cd and Sb (Cominco). Surface oxide was removed by scraping and then melting the metals under vacuum and filtering through Pyrex wool. Appropriate amounts of the metals were weighed on an analytical balance to k0.1 mg, sealed in double Pyrex capsules under vacuum,

Jan 1, 1968

By M. Nicholas, D. M. Poole

The diameters of sessile drops have been found to increase linearly with time in five reacting binary metal systems. The spreading rates of the drops are markedly dependent on temperature and on prior alloying of the solid with the lower melting point metal, hut are independent of the drop volume, wetting atruosphere , solid-surface roughness, and prior alloying of the drop with the substrate metal. A mechanism has been suggested that relates the linear-spreading rate to lateral diffusion of the liquid-metal atoms into the solid at the drop edge. An Arrhenius- type equation has been derived that describes the temperature dependence 0) the spreading rate, and although the agreement between the actual and the predicted pre-exponen-tial terms is poor that between the activation energies is excellent and the variation in the spreading rate of copper on Ni-Cu alloys produced by different extents of alloying can be predicted with considerable accuracy. CHEMICAL interactions frequently change the wetting behavior of solid-liquid systems causing, for example, "secondary spreading1 of sessile drops beyond the size defined by the surface and interfacial tensions of the unreacted components. The kinetics of the contact-angle decreases associated with this spreading are similar for many systems, but few studies have been made with the objective of determining whether the similarities are a reflection of a common mechanism. Some workers2,3 have assumed the secondary spreading is controlled by changes in the liquid surface and liquid-solid interfacial tensions and hence by the composition of the liquid, and contact-angle changes measured by the vertical-plate technique have been used to follow the course of liquid-solid chemical reactions.4 Other processes that have been invoked to explain these time-dependent changes in specific systems include the removal of adsorbed gas from the liquid-solid interface.5 penetration of containment layers on the solid Surface,6 interdiffusion,1,7 reori-entation of the solid surface into a wettable configuration: vapor-phase transport of the liquid onto the solid in advance of the drop,9 and, from vertical-plate studies. capillary flow between oxide layers and the solid surface.10 One of the reasons for the profuseness of these suggestions may be the complexity of the contact-angle change kinetics. However, in an analysis of secondary spreading gold and copper on UC,11 it was found that the diameter of the contact area between the sessile drop and the solid surface showed a simple linear increase with time although contact-angle changes were more complex. To check whether the linearity was merely fortuitous! additional exploratory work was conducted with four reacting metal-metal systems: Au on Ni. Cu on Ni, Cu on Fe, and Ag on Au. Linear spreading was observed in every case even though the kinetics of the contact-angle changes were complex. A further detailed study of the kinetics of linear spreading of five reacting metal-metal systems has been made with the object of determining the mechanism involved. The influence of variables such as temperature, drop volume. and the initial composition of the drop on the linear-spreading rate has been measured and compared with those predicted by a number of possible mechanisms. The systems employed in this study (Cu and Au on Ni and Pt, and Ag on Au) were selected because of the availability of potentially relevant chemical and physical property data. the simplicity of their phase diagrams at the wetting temperatures, and the ease of experimentation. EXPERIMENTAL TECHNIQUES The purities of the metals used in the study were: copper, 99.9 pct; gold. 99.96 pct; nickel, 99.2 pct; platinum 99.99 pct; and silver, 99.999 pct. The wetting tests were performed in a split tantalum tube vacuum resistance furnace of a conventional design. The furnace element was held vertically and was 1 $ in. in diam and 6 in, long. Viewing ports were provided in the water-cooled chamber to enable the specimens to be observed in both the horizontal and vertical planes. The temperature in the hot zone of the furnace could be held at 1500" i 5°C for an indefinite time. The surfaces of the solid-plaque metals were ground flat on Microcut paper and both the sessile drop and substrate metals were ultrasonically cleaned in methyl alcohol prior to their insertion in the furnace. After loading, the furnace was pumped down to a pressure of 2 x 10-5 mm of mercury and degassed for 30 min at 900° to 950°C. The temperature was then increased at more than 100°C per min to that used in the wetting test. The vacuum at the wetting temperature was better than 5 x 10-5 mm of mercury. Dewetting and retraction of the drop on cooling did not occur and the contact-area diameters, therefore, were measured after solidification with a vernier traveling microscope. The diameters quoted later are arithmetic means of ten measurements. The standard error of the mean never exceeded 3 pct and was often less than 1 pct.

Jan 1, 1967

By C. van Dijk

In Sept., 1960, a steam-drive project was started in the solution-gas drive area of the Schoonebeek field. A part(ern of three five-spots and one four-spot was selected covering an area of 65 acres. The pay in the project area has good lateral continuity and dips slightly to the northeut; it is about SO ft thick and permeability increases from 1,000 and at the bottom to approximately 10,000 md at the top. The oil originally in place was 12.6 X 10' bbl. The oil has an in situ viscosity of about 180 cp. At the start of the steam drive the cumulative primary production due to. solution-ga.7 drive amounted id 4 Percent of the oil originally in place. Reservoir pressure had dropped about 120 psi and no significant primary re-.serves remained. Some 11.3 million bbl of steam (all steam quantities are expressed in barrels of water vaporized) have been injected, resulting in production of an additional 4.1 X I0 9bl of oil, or 33 percent of the oil originally in place. This corresponds to a cumulative oil-stearn rario of 0.37 bbllbbl. It appears that the steam preferentially moves r updip while liquids are produced mainly from downdip wells observations indicate that tile steam flows through only the upper part of the formation. The lateral steam distribution in the pattern is satisfacrory since several prodriction wells hardly reacted and, hence, cori tributcd little to the oil production. Production performance and results from material balance calcutlations agree satisfactorily with the results of large-,scale laboratory experiments. On the basis of these experirmental results the .steam drive, together with a cold water follow-up. is expected to bring ultimate recovery to a value of crt leas: 50 percent of the oil originally in place. No serious production problems have been encountered. However, due to mechanical fuilure, two old prodriction wells and one injection well had to be replaced. An extension of the. steam drive in this area is under connstruction. Introduction The Schoonebeek oil field, discovered in 1943 and developed after World War 11, is situated in the eastern part of the Netherlands. The main oil reservoir in this field is the Valanginian sand. A completely sealing fault divides this reservoir into two areas (Fig. 1): the southwestern part of the sand body where primary production is ob- tained by means of a solution-gas drive, and the remain. der where edge-water drive is the production mechanism. In the greater part of the field the reservoir consists of a single, unconsolidated sand body. The net thickness ranges from 30 to 100 ft and the top is between 2,400 and 2,800 ft below sea level. Formation permeability varies from approximately 10,000 md at the top to values of the order of 1,000 md at the bottom, and porosity is about 30 percent. The reservoir contains a paraffinic oil of 25" API gravity with an in situ viscosity of 160 to 180 cp. Initial oil saturation was high (85 to 90 percent). The relatively large quantity of oil in place (more than 10' bbl), and the low ultimate primary recoveries expected from this field — approximately 15 percent stock-tank oil initially in place (STOIIP) for the water-drive area and 5 percent STOIIP for the solution-gas drive area — clearly indicate ample scope for secondary recovery. Because ies-ervoir and crude characteristics made this field suitable for thermal secondary recovery, a hot-water drive project was started in the water-drive area about 10 years ago. A few years later a steam drive and an in situ combustion project were started in the solution-gas drive area. This paper deals with the performance of the steam-drive project, which was started in Sept., 1960, and which is still in operation. Design of Steam-Drive Project, An experimental investigation of the steam-drive process carried out by schenk in 19561 indicated that under schoonebeek conditions steam injection could be an attractive secondary recovery method. the findings and encouraging results of a pilot test in the Mene Grande field in venezuela,i led to the design of a steam-drive project in the schoonebeek field, Pruject Site and Pattern In 1958 the reservoir pressure in the solution-gas drive area had decreased to about 120 psi, and oil production rates of wells in this area had dropped to 7 to 10 B/D. The cumulative primary production was about 4 percent STOIIP, leaving an oil saturation of approximately 85 percent. In view of the large amount of oil left behind in the reservoir, the solution-gas drive area was selected for the planned steam-drive project. The area in the vicinity of Well S1 3 (Fig. 2) was considered to be suitable since it is at least partly isolated from the rest of the field by faults and the sand is relatively thick (about 80 ft).

Jan 1, 1969