Search Documents

By H. T. Kennedy

The fact that intrusion of water into oil wells can be prevented by treating the sand adjacent to the well seems to have been only recently recognized. Swan1 mentions the process of solidifying naphthalene in strata. R. Van A. Mills2 recommends the use of materials such as sodium silicate and sodium carbonate, which react with oil-field water to form solid plugging agents. When a well is drilled in a new field the oil sands are found essentially devoid of water (Fig. 1). Unless a completely impermeable break exists over wide areas in the field, no water is found above the lower limit of the oil zone and no oil is found below the upper limit of the water zone. After considerable oil has been taken from the well, however, it is almost universal experience that water intrusion occurs. This intrusion may be of two kinds. The water may follow a path parallel to the bedding planes of the producing formation through loose streaks in the pay sand, as shown in Fig. 2, or the water level of the field may rise and enter the well by coning (Fig. 3). Water entering from the side is called "edge water," and that coming in from the bottom is called "bottom water.'' Effectiveness of any method for shutting off water depends not only on the effective treatment of the sand adjacent to the well but on

Jan 1, 1936

By Allen F. Agnew

Geologic studies for the Federal and State governments in the Wisconsin-Illinois-Iowa zinc-lead district were begun in 1835, and subse¬quent surveys were made in the three states at in¬tervals until 1916, see Table I. The current study of the district, Fig. 1, by the U. S. Geological Survey was begun in 1942 in the hope that a systematic investigation would help in¬crease production of zinc and lead, then in ex¬tremely short supply. Major emphasis of the USGS program was on detailed mapping of the geologic structure and ore deposits. Preliminary maps and reports covering localities of intensive mining ac¬tivity have been published during the course of this study, Fig. 2. By 1950 the objectives of the study by the USGS were revised; 7Y2-min quadrangles of relatively unprospected localities as well as inten¬sively mined localities are now being mapped in Wisconsin. Since 1945 the investigation in Wiscon¬sin has been made in cooperation with the Wiscon¬sin Geological and Natural History Survey, and since 1951 the geologic mapping of areas of particu¬lar interest in Iowa has been performed in coopera¬tion with the Iowa Geological Survey. At intervals since 1943 the Illinois State Geological Survey has mapped the geologic structure and ore deposits of localities in the Illinois part of the mining district, see Fig. 2.

Aug 1, 1955

By W. S. Landis

WHEN dealing with a new reagent, one is concerned with three principal factors: available supply, cost, and results. The atmosphere contains an inexhaustible supply of oxygen mechanically mixed with nitrogen (omitting rare gases and minor impurities) in the proportions of one volume of oxygen to four volumes of nitrogen. (All figures are based on slide-rule precision and minor impurities are neglected.) Expressed in terms of weight, 1 ton of oxygen represents a volume of 22,500 cu. ft. and is contained in a volume of 112,000 cu. ft. of air. Water, also an inexhaustible supply, is a chemical compound containing 89 per cent. oxygen and, 11 per cent. hydrogen. Of the hundreds of schemes proposed for the enriching of air or separation of oxygen, nothing of value has yet appeared. From the standpoint of mechanical separation, liquefaction followed by rectification is the only process that has been developed to a really commercial stage. Theoretically, it should be a .simple matter to separate the mechanical mixture of nitrogen and oxygen; but fractionation can be performed only by converting to the liquid phase and this phase can be obtained only at lower than critical temperatures. The problem, therefore, is not so simple and the cost of the actual operation bears no relationship to the theoretical simplicity of the process. The largest single unit of the required apparatus so far placed in commercial use will handle only 60,000 cu. ft. of air per hour through a compressor which operates at a little over 250 lb. per sq. in. After this apparatus has operated continuously for 14 to 18 days it must be shut down for 6 to 8 hr. to be thawed out, have accumulated impurities removed and again cooled down for production. The cost of such a unit erected in batteries, with necessary spares for maintaining production, and including prime movers, hoisting and all auxiliary equipment, will be about $125,000. To produce one ton of oxygen per hour requires two operating machines of this size; and if the production is to be absolutely continuous a spare unit must be provided. To operate a plant of two units requires 10 or 11 men, excluding boiler attendants, if steam is generated in the plant.

Jan 11, 1924

By Charles N. Becker

The practice of drying phosphate in Florida is as old as the industry, which began a little more than half a century ago. The methods, however, have changed considerably. At first, the natural process of exposure to the sun and air was used, later supplemented by wood fires beneath open-air stationary dry kilns and drying towers of various designs. It was not until the early nineties that rotary driers came into use, and at first they were of very small design and fired with wood. As the industry grew and tonnage increased, so likewise grew the number and size of rotary driers, until today the largest installations are 6 ft. up to 7 ft. 6 in. in diameter, and 55 to 60 ft. long, fired with crude oil. The reasons for drying phosphate rock are: (1) to eliminate freight on water in the shipment and (2) to facilitate the good grinding qualities required by the buyers in their acidulation. Phosphate pebbles vary materially in natural characteristics and each property has a direct bearing on the processing. In making comparisons of cost and operating conditions, the following are usually taken into consideration: 1. The hard dense pebbles, which contain very little interior moisture and 6 to 8 per cent total moisture, usually produced from the low-grade deposits. 2. The lighter, porous pebbles, which contain 4 to 5 per cent interior moisture and a total moisture ranging from 9 to 15 per cent. 3. The product of recovery operations using oily reagents, containing from 15 to 25 per cent moisture. 4. The size of the pebbles Usually the plus 5-mesh material is considered as "coarse rock"; the minus 5-mesh plus 24-mesh is "fine rock," and the minute particles below 24 mesh are called "concentrate." 5. The amount of moisture allowed in the dried product. The practice is generally to dry down to 1.5 to 2 per cent moisture. There is, however, an actual range in guarantee of from 1 per cent maximum to 3 per cent maximum.

Jan 1, 1938

By Charles N. Becker

The practice of drying phosphate in Florida is as old as the industry, which began a little more than half a century ago. The methods, however, have changed considerably. At first, the natural process of exposure to the sun and air was used, later supplemented by wood fires beneath open-air stationary dry kilns and drying towers of various designs. It was not until the early nineties that rotary driers came into use, and at first they were of very small design and fired with wood. As the industry grew and tonnage increased, so likewise grew the number and size of rotary driers, until today the largest installations are 6 ft. up to 7 ft. 6 in. in diameter, and 55 to 60 ft. long, fired with crude oil. The reasons for drying phosphate rock are: (1) to eliminate freight on water in the shipment and (2) to facilitate the good grinding qualities required by the buyers in their acidulation. Phosphate pebbles vary materially in natural characteristics and each property has a direct bearing on the processing. In making comparisons of cost and operating conditions, the following are usually taken into consideration: 1. The hard dense pebbles, which contain very little interior moisture and 6 to 8 per cent total moisture, usually produced from the low-grade deposits. 2. The lighter, porous pebbles, which contain 4 to 5 per cent interior moisture and a total moisture ranging from 9 to 15 per cent. 3. The product of recovery operations using oily reagents, containing from 15 to 25 per cent moisture. 4. The size of the pebbles Usually the plus 5-mesh material is considered as "coarse rock"; the minus 5-mesh plus 24-mesh is "fine rock," and the minute particles below 24 mesh are called "concentrate." 5. The amount of moisture allowed in the dried product. The practice is generally to dry down to 1.5 to 2 per cent moisture. There is, however, an actual range in guarantee of from 1 per cent maximum to 3 per cent maximum.

Jan 1, 1938

By W. J. Locher

One important means of reducing steel consumption in grinding mills is not mentioned in S.G. Malghan's paper. It is simply to reduce the oxygen content in the mill and pulp. While oxygen dissolved in pulp is not readily reduced without additives, reduced aeration and reduced ventilation of grinding mills are often feasible. It is not necessary to completely eliminate the oxygen to achieve substantial benefits, since corrosion rates vary with oxygen content in a manner analogous to combustion rates as oxygen content increases. It is difficult to generate indisputable quantitative data on the relationship of oxygen reduction in a milling system to changes in consumption of grinding steel. Perhaps this accounts for the absence of technical papers on the effects of reducing oxygen content in grinding mills by reducing aeration of pulp and ventilation of grinding mills. One qualitative observation is that mills operating at a lower percent of critical speed will tend to have lower media consumption for similar fineness of grind without necessarily having an equivalent reduction in power consumption per ton of product. Reduced mill speed would also tend to reduce both ventilation of the mill and entrainment of air in the pulp. Larger grinding mills tend to be more media efficient because they operate at a greater ratio of charge volume to pulp surface area, which will tend to reduce the aeration per unit of pulp volume. The mechanical steps required to reduce aeration of grinding mill pulps depend on the configuration of the grinding circuit and related process. Reply by S.G. Malghan Mr. Locher stated that my paper did not mention the reduction of oxygen content of the pulp as a potential method of decreasing the steel consumption. I would like to bring to the attention of Mr. Locher that an indirect reference was made to the fact that pulp oxidation potential controls the corrosion wear of steel. Though dissolved oxygen is one of the factors that controls oxidation potential, additional discussion was deliberately avoided for the reasons mentioned by Mr. Locher. The most important reason being the difficulty of decreasing and controlling the oxygen concentration of the pulp in a commercial mill.

Jan 1, 1984

By Charles Becker

THE practice of drying phosphate in Florida is as old as the industry, which began a little more than half a century ago. The methods, however, have changed considerably. At first, the natural process of exposure to the sun and air was used, later supplemented by wood fires beneath open-air stationary dry kilns and drying towers of various designs. It was not until the early nineties that rotary driers came into use, and at first they were of very small design and fired with wood. As the industry grew and tonnage increased, so likewise grew the number and size of rotary driers, until today the largest installations are 6 ft. up to 7 ft. 6 in. in diameter, and 55 to 60 ft. long, fired with crude oil. The reasons for drying phosphate rock are: (1) to eliminate freight on water in the shipment and (2) to facilitate the good grinding qualities required by the buyers in their acidulation. Phosphate pebbles vary materially in natural characteristics and each property has a direct bearing on the processing. In making comparisons of cost and operating conditions, the following are usually taken into consideration: 1. The hard dense pebbles, which contain very little interior moisture and 6 to 8 per cent total moisture, usually produced from the low-grade deposits. 2. The lighter, porous pebbles, which contain 4 to 5 per cent interior moisture and a total moisture ranging from 9 to 15 per cent. 3. The product of recovery operations using oily reagents, containing from 15 to 25 per cent moisture. 4. The size of the pebbles. Usually the plus 5-mesh material is considered as "coarse rock"; the minus 5-mesh plus 24-mesh is "fine rock," and the minute particles below 24 mesh are called "concentrate." 5. The amount of moisture allowed in the dried product. The practice is generally to dry down to 1.5 to 2 per cent moisture. There is, however, an actual range in guarantee of from 1 per cent maximum to 3 per cent maximum.

Jan 1, 1936

By N. O. Johnson, J. Boyer, D. H. Sargent, R. B. Frahme

Although the Western bentonite industry has grown rapidly, it is facing major challenges to sustained growth. The fundamental penalty of costly overland transportation to both domestic markets and to US seaports is of increasing importance; as both substitute materials and foreign bentonites present more formidable competition in the historic market areas of drilling muds, foundry sands, and iron ore pelletizing; and as foreign demand grows more rapidly than domestic demand. The Western bentonite industry is facing these challenges by altering its transportation patterns, by upgrading of products, and by emphasizing customer service and stringent quality control.

Jan 1, 1980

By N. O. Johnson, J. Boyer, D. H. Sargent, R. B. Frahme

Although the Western bentonite industry has grown rapidly, it is facing major challenges to sustained growth. The fundamental penalty of costly overland transportation to both domestic markets and to US seaports is of increasing importance; as both substitute materials and foreign bentonites present more formidable competition in the historic market areas of drilling muds, foundry sands, and iron ore pelletizing; and as foreign demand grows more rapidly than domestic demand. The Western bentonite industry is facing these challenges by altering its transportation patterns, by upgrading of products, and by emphasizing customer service and stringent quality control.

Jan 9, 1979

By Walter E. Duncan

The ores treated at the concentrating plant of the Mahoning Mining Co. at Rosiclare, Ill., come largely from the blanket replacement deposits of the northeastern part of Hardin County, Illinois, and consist of complex mixtures of galena, sphalerite and fluorspar in a gangue of quartz, limestone and sandstone. The several minerals are so intimately inter-grown that they are not liberated at the sizes usually treated by gravity concentration in the usual fluorspar plant. For this reason, an all-flotation method of concentration was developed in cooperation with the station of the U. S. Bureau of Mines at Rolla, Mo.1 This flotation separation made possible the commercial production of four coyentrates: (I) lead, (2) zinc, (3) acid-grade fluorspar and (4) metallurgical-grade Auorspar.2-3 Although fluorspar had been floated in Canada in 19214 and a plant at Rosiclare had been floating fluorspar since March 1929, fluorspar flotation was given considerable impetus by the Mahoning developments, since some features of the separation were quickly adopted by other fluorspar companies. The Bureau of Alines5 reports that in the 10 years preceding 1938 only 50,552 tons of fluorspar flotation concentrates were produced in the United States. The rise from this almost nominal figure to 153,750 tons (largely acid grade) in one year (1944)6 is indicative of the activity in fluorspar flotation occasioned by the war. The industry thus proved to be in a position to expand and keep up reasonably well with the requirements imposed upon it by such developments as occurred in high octane aviation gasoline alkylation, in the use of Freon as a refrigerant and as carrier in the Aerosol "bug bomb," and in the atomic bomb project as well as in the expansion of other activities requiring hydrofluoric acid; for example, the aluminum industry. Despite the fact that the greater portion of acid-grade fluorspar produced in the last few years went directly into war uses, the future of the acid-grade field still appears bright. As a result of the activity in fluorine chemistry during the war, it seems likely that in the relatively near future almost every phase of human endeavor will find some fluorine compound involved. The other three concentrates produced deserve some attention in these introductory remarks. The lead concentrates first produced contained both zinc and fluorspar but these did not interfere with their marketing. As will be pointed out later, the quality has steadily improved until today it is a relatively high-grade product. Although some zinc smelters accept concentrates containing limited quantities of fluorspar, it is a very objectionable impurity. Since flotation methods fail in the complete removal of the fluorspar, chemical methods were developed for

Jan 1, 1948

By Walter E. Duncan

THE ores treated at the concentrating plant largely come from the blanket replacement deposits of the northeastern part of Hardin County, Illinois, and consist of complex mixtures of galena, sphalerite and fluorspar in a gangue of quartz, limestone and sandstone. The several minerals are so intimately intergrown that they are not liberated at the sizes usually treated by gravity concentration in the usual fluorspar plant. For this reason, an all-flotation method of concentration was developed in cooperation with the station of the U. S. Bureau of Mines at Rolla, Mo.1 This flotation separation made possible the commercial production of four concentrates: (I) lead concentrates, (2) zinc concentrates, (3) acid-grade fluorspar concentrates and (4) metallurgical-grade fluorspar concentrates.2,3 Although fluorspar had been floated in Canada in 1921 4 and a plant at Rosiclare had been floating fluorspar since March 1929, fluorspar flotation was given considerable impetus by the Mahoning developments, since some features of the separation were quickly adopted by other fluorspar companies. The Bureau of Mines5 reports that in the 10 years preceding 1938 only 50,552 tons of fluorspar flotation concentrates were produced in the United States. The rise from this almost nominal figure to 153,750 tons (largely acid grade) in one year (1944)6 is indicative of the activity in fluorspar flotation occasioned by the war. The industry thus proved to be in a position to expand and keep up reasonably well with the requirements imposed upon it by such developments as occurred in high octane aviation gasoline alkylation, in the use of Freon as a refrigerant and as carrier in the Aerosol "bug bomb," and in the atomic bomb project as well as in the expansion of other activities requiring hydrofluoric acid; such as, for example, the aluminum industry. Despite the fact that the greater portion of acid-grade fluorspar produced in the last few years went directly into war uses, the future of the acid-grade field still appears bright. As a result of the activity in fluorine chemistry during the war, it seems likely that in the relatively near future almost every phase of human endeavor will find some fluorine compound involved. The other three concentrates produced deserve some attention in these introductory remarks. The lead concentrates first produced contained both zinc and fluorspar but these did not interfere with their marketing. As will be pointed out later, the quality has steadily improved until today it is a relatively high-grade product. Although some zinc smelters accept concentrates containing limited quantities of fluorspar, it is a very objectionable impurity. Since flotation methods fail in the complete removal of the fluorspar, chemical methods were developed for

Jan 1, 1946

By Walter E. Duncan

The ores treated at the concentrating plant of the Mahoning Mining Co. at Rosiclare, Ill., come largely from the blanket replacement deposits of the northeastern part of Hardin County, Illinois, and consist of complex mixtures of galena, sphalerite and fluorspar in a gangue of quartz, limestone and sandstone. The several minerals are so intimately inter-grown that they are not liberated at the sizes usually treated by gravity concentration in the usual fluorspar plant. For this reason, an all-flotation method of concentration was developed in cooperation with the station of the U. S. Bureau of Mines at Rolla, Mo.1 This flotation separation made possible the commercial production of four coyentrates: (I) lead, (2) zinc, (3) acid-grade fluorspar and (4) metallurgical-grade Auorspar.2-3 Although fluorspar had been floated in Canada in 19214 and a plant at Rosiclare had been floating fluorspar since March 1929, fluorspar flotation was given considerable impetus by the Mahoning developments, since some features of the separation were quickly adopted by other fluorspar companies. The Bureau of Alines5 reports that in the 10 years preceding 1938 only 50,552 tons of fluorspar flotation concentrates were produced in the United States. The rise from this almost nominal figure to 153,750 tons (largely acid grade) in one year (1944)6 is indicative of the activity in fluorspar flotation occasioned by the war. The industry thus proved to be in a position to expand and keep up reasonably well with the requirements imposed upon it by such developments as occurred in high octane aviation gasoline alkylation, in the use of Freon as a refrigerant and as carrier in the Aerosol "bug bomb," and in the atomic bomb project as well as in the expansion of other activities requiring hydrofluoric acid; for example, the aluminum industry. Despite the fact that the greater portion of acid-grade fluorspar produced in the last few years went directly into war uses, the future of the acid-grade field still appears bright. As a result of the activity in fluorine chemistry during the war, it seems likely that in the relatively near future almost every phase of human endeavor will find some fluorine compound involved. The other three concentrates produced deserve some attention in these introductory remarks. The lead concentrates first produced contained both zinc and fluorspar but these did not interfere with their marketing. As will be pointed out later, the quality has steadily improved until today it is a relatively high-grade product. Although some zinc smelters accept concentrates containing limited quantities of fluorspar, it is a very objectionable impurity. Since flotation methods fail in the complete removal of the fluorspar, chemical methods were developed for

Jan 1, 1948

By Robert U. King

The Climax Molybdenum Company's mine is situated on the Continental Divide at Fremont Pass in Lake County, Colorado. Elevations at the mine range from 11,000 it. to over 12,000 ft. The ore body is on the south flank of Bartlett Mountain, a prominent peak in the Ten Mile Range. A horizontal section of the mine, such as the Phillipson level (Fig. I), shows the outer ore zone as an annular ring varying in width from 300 to 800 ft., surrounding barren silicified rock. In vertical section the outer ore zone is dome shaped (Figs. 2 and 3), the apex of which is truncated at the surface by glaciation, exposing part of the ore body. The outer ore zone overlies the barren core and is itself overlain on the flanks of the dome with unmineralized rock. An ore zone of similar shape underlies the barren core of silicified rock, known as the Central Ore Zone (Figs. 2 and 3). Molybdenite is distributed uniformly through a zone of moderately silicified granite, schist and quartz monzonite (early) porphyry, around a highly silicified core. The molybdenite occurs in veinlets associated with fine granular quartz and pyrite, replacing altered and fractured granite, schist, and porphyry, and as coatings on numerous fractures cutting these rocks. Intense fracturing of all rocks is a characteristic feature of the Climax ore body. Most fractures are mineralized and no longer represent planes of weakness. Much fracturing is postmineral, however, and these fractures are generally filled with sericite or gouge, or remain as unmineralized joints separating otherwise massive rock into blocks of various size. Study and Mapping of Caving Characteristics Important differences in the behavior of caving of various blocks of ore at Climax have been recognized, involving arching of the rock over caved stopes, tendency of caved rocks to funnel, and size of caved rocks. Also, new problems have arisen associated with future mining on the Phillipson level, and may occur with proposed development of lower levels, such as excessive stress on mine pillars caused by large masses of overlying stable rock, and higher costs in maintenance of mine workings in soft, weak rock. To explain the differences and to provide solution for these problems, a study of geologic structure was undertaken early in 1944, to determine whether it would be possible to map cavability of rock from physical features exposed in mine workings and in diamond-drill cores. A comparison of known caved areas was made and rocks were classified structurally according to strength or degree of cavabil-ity. As nothing of this nature had been done before at Climax, the approach to the problem was rather indefinite. Several trials were made with negative results, but collectively indicated a suitable method. This was to examine all mine workings and diamond-drill cores, record-

Jan 1, 1946

By W. H. Basssett

THE amount of oxygen present in refined copper bears an important relation to the effects of various impurities on physical properties of copper, as well as the effects of reducing gases at higher temperatures. It seems fitting at this time, when the effects of reducing gases on copper are being discussed, to describe methods that have proved satisfactory for the determination of oxygen and sulfur, and to present some results obtained by investigation of these methods in the authors' laboratory. The procedure for the determination of sulfur is closely interrelated with that for oxygen and has, therefore, been included. It was first proposed by Hamper that oxides in copper could be accurately determined by the loss in weight sustained by finely divided copper when reduced at red heat in pure hydrogen, or by the weight of water produced. Hampe's method was later modified by Archbutt,2 who established the accuracy of the method and demonstrated that equally accurate results were obtained by noting the loss in weight or by weighing the water formed. The determination of oxygen by heating in carbon monoxide has been proposed by West.3 In our hands this method has given slightly lower results than obtained by heating in hydrogen.

Jan 2, 1926

By Herbert Hoover

This paper is in the nature of a rough preliminary report on the progress that has been made in the application of the mass spectrometer to various problems arising in the petroleum industry. A few years ago the authors considered a number of the problems that were arising in the qualitative and quantitative measurement of small amounts of hydrocarbons. The methods available of making analyses by chemical techniques appeared to leave much room for improvement. Without going into the reasons at this point, attention was turned to the possibility of employing physical instead of chemical methods of accomplish-ing the desired results. A preliminary investigation disclosed that the mass spectrometer presented a possibility of solving many problems which could not easily be accomplished by other methods. Work was begun in developing the necessary apparatus and technique. A great deal of encouragement and many valuable suggestions were received from Dr. Robert A. Millikan, Dr. W. R. Smythe, and Dr. W. N. Lacey, of the California Institute of Technology, and from Dr. E. 0. Lawrence, who recently received the Nobel Prize, of the University of California. The authors particularly wish to acknowl-edge the very great willingness of these out-standing scientists to be helpful in solving many of the problems that were involved. So far as the authors are aware, this was the first application of the mass spectrometer to commercial work. The results were considerably better than had at first been anticipated. Briefly, it is pos-sible to run a qualitative and quantitative analysis of an unknown mixture of hydro-carbon gases, with an accuracy of better than plus or minus 5 per cent of each of the various constituents. An exceedingly high degree of sensitivity has been obtained, and a relatively short time is required to com-plete an analysis. Furthermore, it is un-necessary to separate a mixture of gases into its various components in order to complete the analysis.

Jan 1, 1940

By R. G. Davies

Above 500°C, where dislocation climb is rate controlling, it is observed that the activation energy for creep is independent of the apblied stress, although it varies from 62 kcal per mol at 15 pct A1 to 73 kcals per mol at 20 pctA1 due to the change in short-range ovdw with composition. Below 500°C, when the nonconservative motion of jogs upon dislocations is thought to be rate controlling, the activation energy is stress dependent. A sudden increase in the creep rate, for which no explanation is availab2e, occurs at the highest stress at all temperatures. CREEP has been the subject of numerous research publications during the past decade with most of the attention focused upon high temperature steady state creep, i.e., above 0.5 TM, where TM is the absolute melting temperature, as it is the most amenable to theory. Many of the proposed theories involve the climb of dislocations out of their slip plane, which allows them to circumvent obstacles or to annihilate dislocations of opposite sign on other slip planes.' For pure metals it is observed that the activation energy for this creep is equal to the activation energy for self diffusion.' The position is much more complicated in alloys as there are many possible microcreep mehanisms, as well as dislocation climb, which could be rate controlling. There has been little systematic investi- gation of alloys, but Weertman (lead and indium base alloys)3 and Lawley, Coll, and Cahn (Fe-A1 alloys)4 suggest a microcreep process as the controlling factor. A Cottrell-Jaswon atmosphere mechanism is proposed for the lead and indium alloys, and a mechanism involving crystallographic order for the Fe-A1 alloys. Lawley et al. showed that the formation of a super-lattice, either of the FeAl or Fe3A1 type. decreased the rate and increased the activation energy for creep. From the measurements of lattice parameters,= resistivity,' magnetic properties,7'8 internal friction: and dilatometry10 the ordered region is thought to commence at -19 at. pct Al. However, a recent investigation by the author indicates a value

Jan 1, 1963

By G. P. Conard, E. H. Rennhack

The generation of fibers composed of individual TiZn15 compound particles and their influence on crystallographic orientation in chill-cast, hot-rolled hypoentectic Zn-Ti alloys were explored. Metallo-graphic examination and X-ray diffraction data show that such fibers form a planar network after 50 pet reduction which eventually tends to suppress twinning at some critical reduction level (-90 pct) where the grain size approaches the interfiber, spacing. This leads to the development of a duplex-type projerred orientation through slip rotation consisting of an al-most ideal (0001)(2iiOj texture and a (0001) (1010) rotated component. Correlations between basal-plane rotation and secondary- creep rc11e sugg-est, however that prejerred orientation does not contribute in a major way to the creep resistance of these alloys. EFFORTS to improve the creep resistance of zinc through alloying without incurring a loss in fabricating properties have achieved only minor success with the exception of the very effective addition of titanium. Anderson, Boyle, and Ramsey,l for example, demonstrated that increasing the amount of thiselement from 0.05 to 0.23 wt pct produced a progressive, 45-fold increase in the inverse creep rate of hot-rolled

Jan 1, 1967

By Eldon N. Dunlap

Recently the producing branch of the petroleum industry has shown a considerable and growing interest in the quantitative determination of the water, oil, and gas content of cores as it relates to estimation of reserves, to providing a basis for judging as to the feasibility of applying various secondary-recovery and pressure-maintenance processes, and in general to the operation of producing properties. For years it has been known that oil, gas and water coexisted in the pores of many semidepleted oil measures. It is now generally believed that oil-bearing beds contain connate water in amounts varying up to 50 per cent of the pore space. However, only lately has reliable direct evidence of the extensive occurrence of connate water in oil sands been published. Very little work has been done to ascertain the effect of this water on the productivity and ultimate recovery of oil from wells. It was the intent of this research to study the influence of interstitial water on the flow of oil through unconsolidated sands, with the hope that the results could be applied qualitatively to the flow of oil in underground reservoirs partly saturated with water. Obviously, ultimate recovery estimates based on the void volume of the reservoir will be in error unless a correction is made for the volume of water that occupies a portion of the effective pore volume of the reservoir. Evaluation engineers in the past have applied arbitrary saturation and recovery factors that may inadverently have compensated for the failure to consider specifically the water content. Nevertheless, the evidence available indicates that these factors need revising if each is to be independently correct and truly representative. Although the fact that the connate water renders part of the pore volume of the reservoir incapable of containing oil is of primary importance to the operator, it is also to his interest to know to what extent the presence of varying amounts of interstitial water influences the permeability of the sand to oil.

Jan 1, 1938

By William B. Plank

ENGINEERING educators and industries are worried about the engineering manpower shortage that is predicted as a result of the increasing demand for trained engineers not only by industry but by the armed services. This is in the face of a decreasing supply, as is shown by this and other studies. Not only has the number of entering freshmen been decreasing since 1947, because of a decrease in the number of high school graduates entering engineering, but the total number of high school graduates will continue to decrease until 1958 because of the lowered birth rate during the depression years.

Jan 8, 1951

By P. H. Mell

CAN the auriferous slate deposits of the Southern mining region ever be successfully worked? is a question that has been often asked me by persons seeking investments in Southern mines. As the subject is one that has given me much thought during the past few years, I have decided to present my conclusions to the members of the Institute for their consideration. Those who have had the opportunity of exploring the region mentioned above, will readily recall to mind numerous localities, to which their attention was directed by would-be miners, as "rich and desirable properties," in which there were but few quartz seams running in every direction through fine-grained talcose slate. Most of the gold in sued formations was always found disseminated through the slate, and but a small percentage contained in the quartz. Such are the deposits I propose to discuss in this paper. Of course there are many excellent quartz mines in the South that are paying the owners good profits, and many more to my knowledge, that are not being worked for obvious reasons. But it is out of the question to suppose that these slate deposits can be practically

Jan 1, 1881