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By Alden B. Greninger

In a recent study1 of the deformation of metastable beta copper-zinc and beta copper-tin crystals, it was established that the parallel markings that appear on the surface of these crystals after slight deformation represent lattice transformations. Stereographic analysis showed that in beta copper-tin, the poles of these markings deviated one or two degrees from poles of the form {133}. In beta copper-zinc the plane delineated by the markings corresponded to no one crystallographic plane of the matrix lattice; the marking poles deviated from 5° to 11° from poles of the form (110), and were displaced only a few degrees from (110) zones. Inasmuch as the new transition lattices produced as the result of the deformation are different for each alloy, it was thought at first that the habits of the markings might be the result of a cooperation between matrix lattice and transformed lattice. (Both matrix lattices arc body-centered cubic.) Such a cooperative effect is thought to obtain in the formation of Widmanstätten figures, for it is well known that the matrix lattice alone does not determine the habit assumed by a segregate phase. On the other hand, it is not inconceivable that the dissimilarity in marking habit might be due to differences in deformation characteristics of beta brass and beta bronze. Barrett and co-workers2 have shown that slip-line habits in pure iron are markedly different from those in high-silicon ferrite; and although it has been repeatedly demonstrated that plates of a segregate phase do not necessarily form on the slip planes of the matrix lattice, deformation characteristics may be more intimately allied with plate formation when a transformation is made to occur as a result of plastic deformation. However, there is the fact that the orientation of markings in metastable beta copper-zinc is the same whether the markings be produced by quenching, deformation, or liquid-air cooling; likewise, quenching and deformation markings in metastable beta copper-tin are oriented in the same way with respect to the beta matrix. During the course of the investigation referred to above, samples of 52:48 (stable beta) copper-zinc were deformed and examined micro-

Jan 1, 1938

By Gerhard Derge

EXTRUSION processes are used in the commercial production of a wide variety of products, as indicated by the review presented a few years ago by D. K. Crampton.1 Most writers have confined themselves to a general description of the equipment and products and the engineer-ing aspects of the process. The few studies that have dealt with the metallurgical side of extrusion have been concerned primarily with an examination of the mode of flow of the metal during extrusion. This has been accomplished by the use of composite billets, by scribing grids on symmetrical sections of billets and observing the change of dimensions in the gridwork, or by examining microstructures in extruded sections.2-8 Another limitation of these original studies is that they were confined to the extrusion of very simple shapes, usually rods having a diameter of about one-fourth that of the billet. Tin is particularly well suited to the extrusion of collapsible tubes and similar shapes in which the extruded section is very small in comparison to the diameter of the billet or slug. In modern production, impact extrusion methods are generally employed, therefore the thickness of the slug is small compared to its diameter. Under these conditions the process differs considerably from the processes that have been most fully described in the literature, and it is known that the quality of the product is very sensitive to slight variations in any one of the many variable factors involved, such as composition and structure of the alloy, rate of extrusion, temperature, shape of punch and die. An exhaustive examination of all of the above-mentioned problems promises to produce so many data that it seems advisable to initiate the reports at this time, even though all of the factors outlined have not been examined fully, and to confine this paper to a description of the apparatus and method. Only tin and its alloys with small amounts of copper have been considered. These are the alloys most commonly used in this country for the production of the type of articles already described.

Jan 1, 1939

By Ben-Zion Weiss, Melvin R. Meyerson

FATIGUE crack propagation in some aspects can be viewed as being a result of localized plastic deformation concentrated near the tip of the crack.' Deformation is influenced by microstructure which in turn can affect the fatigue crack growth significantly. To study the effect of localized microstructural changes on fatigue crack propagation, cantilever-type notched specimens were subjected to cyclic bending at constant load amplitude. The extent of fatigue crack propagation was obtained by measuring the length of the crack by periodic observation with a microscope on the polished side of the sample,2"4 and these data were used in preparing the curves in the figures which follow. Figs. 1 (solid lines) and 2 show experimental results obtained in austenitic type 302 stainless steel containing higher than standard carbon (0.24 pct C) and 310 stainless steel. Both steels were homogenized for 8 hr at 1120°C and then water-quenched in order to prevent the precipitation of carbides. Fig. 3 shows experimental results obtained on 9440 low alloy steel in the normalized condition and in the quenched and tempered (580°C) condition. Indications of microstructural influence can be seen in scattering of the experimental data. The degree of scattering depends on both the microstructure and the amount of cyclic stress applied to the sample. For microstructures which are more easily deformed plastically, e.g., normalized or annealed as compared with hardened and tempered structures, the scattering is greater. Similarly, higher stresses produce greater scattering in the results, regardless of whether the cause of the stress increase is due to initial loading conditions or the growth in crack length. Scattering is believed to be a result of partial redistribution in the stress field around the tip caused by plastic deformation. This opinion is borne out by much smaller scattering of experimental results in the austenitic 302 high-carbon (0.24 pct C) steel. In this steel, plastic deformation in the neighborhood of the crack causes partial mar-tensitic transformation of metastable austenite,5 which in turn restrains further plastic deformation. As a result, the stress redistribution around The tip is reduced. Partial martensitic transformation was confirmed

Jan 1, 1969

By Charles Baker

THE district of Catorce, San Luis Potosi, ranks among the first half-dozen silver-producing camps f Mexico. Mining has been more or less continuous there for 150 years. The large producing mines, Mapum, Mazapil, Palomas, Musquiz, Minas Virjas, now for the most part idle or abandoned, are grouped around the head of two valleys: one, which drains to the west, falls 2000 ft. (609.6 m.) in 4 1/2 mi. (7.2 km.) between the main Catorce and the western foot of the range and is characterized by steep canon walls; the other, east of the main town of Catorce from which it is separated by a high divide, heads in a number of steep tributaries above the basin in which lies the town of Potrero and flows nearly north for 10 mi. (16 km.) to the northern base of the range; below Potrero, it has for the most part gently sloping valley walls and a broad valley floor. The Sierra Catorce is the highest range of the region, the summits reaching altitudes of over 11,000 ft. With the exception of a few cliffs of the erosion escarpment of the lower limestone and the canon walls below the main town of Catorce, which is the highest town in Mexico, the gently rounded slopes are characteristic of a maturely eroded mountain range composed of folded sedimentary rocks. As is usual in desert regions, the heavy-bedded limestones are the most resistant to erosive forces. Folded into anticlines, they form the mountain ranges; and the intermontane valleys and basins, originally carved out of less resistant shales, clays, marls and sandstones, are covered by debris forming a mantle with surface gradually rising upwards toward the hills. In time, the debris buries, in deposits formed from their own ruins, all but the highest summits of the original mountains; some f this region has already nearly reached this stage. Most of the debris is firmly cemented by calcium carbonate (caliche). Solution f the limestone by meteoric waters afforded the supply of lime carbonate, which has been redeposited upon evaporation of the waters as a cement binding the boulders, pebbles, and finer detritus.

Jan 9, 1921

By R. L. Wiegel

This article proposes a physical model for an idealized binary mineral system and for the process of liberation by size reduction. Based on this model, equations are derived relating the amount of each component liberated as a function of the ratio of the volumetric abundance of the two mineral components and the ratio of the mineral grain size to particle size. A definite relationship is shown to exist between the mineral concentration within a locked particle and the frequency of occurrence of such a particle. These relationships are used to obtain theoretical expressions for the concentration-recovery diagram. Physical mineral beneficiation processes are based on breaking a mineral aggregate to liberate the dissimilar mineral grains and then making use of their physical properties to separate the mixture into its components. The effectiveness of the process is therefore dependent on how well the minerals are liberated and how efficiently they are separated. Although a substantial amount of work is being done to improve our understanding of mineral separation processes, the study of mineral liberation itself has been almost completely neglected. The purpose of this theoretical study is to shed some light on the liberation phenomenon by: 1) proposing a physical model for an ideal binary mineral system, 2) treating mathematically the fracture of this system into liberated and locked particles, and 3) deriving an expression for the liberation characteristics of this system. The results of this study are useful in understanding the effect and importance of various parameters in liberation, and provide a basis for comparison with real mineral systems. 'RANDOM' MODEL It is recognized that liberation can be caused by detachment which results from fractures occurring at the mineral grain boundaries, or by size reduction which restricts the occurrence of dissimilar mineral locking to a portion of the resulting particles. The detachment effect is dependent on the relative strengths of the mineral grains and the bonds between them, and must be treated empirically for each mineral system. The size reduction effect, however, can be treated analytically if certain assumptions are made concerning the shape and geometrical arrangement of the mineral grains.

Jan 1, 1968

By E. H. Griswold, W. J. Wilkins

Pressure control of oil wells may be defined as the adjustment of pressures within a well to obtain the most efficient and economic utilization of the natural gas energy with a minimum of sand troubles or irregular water encroachment. The purpose of this paper is to present the methods used by the writers in applying pressure control and a discussion of the various effects occurring within the wells affected. The benefits to be derived from the conservation of natural gas energy have been so adequately discussed and demonstrated in prior papers by various engineers that the effects on ultimate production will not be discussed other than to mention a few representative cases. The detrimental effects of irregular edge-water encroachment and of sanding up arc of general knowledge to the industry. Effect on Ultimate Production One of the strongest objections voiced against pressure control is that of the danger or inadvisability of deferring oil production by cutting the rate of production. It has been our experience that such deferred product'ion is returned within a few weeks or months rather than years and that an increased cumulative oil production is obtained in the early life of the well by conserving the natural energy. In many cases the rate of production is increased rather than decreased by the adjustment of pressures to obtain the minimum gas factor. Fig. 1 shows the history of a Wilcox sand well in northern Oklahoma, which was pressure-controlled from completion. It is noted that during the early months while flowing naturally through the casing the gas factor was decreased rather than allowed to follow its natural tendency to increase. A string of 21/2-in. tubing was run to restrict the flow and resulted in a decreased gas factor with a more sustained rate of production. When first placed on gas-lift the gas factor again tended to increase, but after the proper pressure adjustments were made, remained approximately steady. It was necessary to defer 100 bbl. per day of oil production in order to maintain this low gas factor. In March serious

Jan 1, 1929

By F. B. Plummer, R. B. Newcome

The practice of introducing acid into oil wells to increase production of oil and gas has been in use since 1894, when it was first used in the Pennsylvania oil fields30.‡ It is only since 1928 that it has been used to any extent in the Mid-Continent18. The process has proved successful in increasing production, at least temporarily, in depleted oil fields where the producing formation is highly calcareous and where water drive is not too pronounced. In the Zwolle field in Louisiana, where the producing horizon is a chalk, increases of 100 per cent have been recorded25. In north-central Texas, where the oil is produced from the Marble Falls limestone, equally pronounced increases have resulted3. The production also in some fields yielding oil from quartz sand cemented with calcitc has been benefited. The evidence of actual increase in total recovery of oil, however, has been questioned by some engineers18. It has been pointed out that the results of the treatment of a well in a now district, where the process has never been tried out, can never be predicted with certainty, since other factors besides percentage of calcareous content of the oil sand play a large part in determining the success of the method. Numerous articles have been published on acid treatment and on the effects of acid on limestone1-35, yet very little has been written concerning experimental work on the actual effect of acid on capillary pores and larger oil-coated voids of oil sands. This is due partly to difficulties in duplicating field conditions in a laboratory and partly to the fact that the process has been carried out largely by contracting companies that have been unwilling to publish details of their results for fear of loss of business to competitors. The authors, using equipment developed to measure the radial permeability of oil-sand cores2', have developed a method of investigating the results of acid treatment which has enabled them to test numerous cores and to study in some detail the action of acid on the different types of rocks, particularly fine-grained rocks.

Jan 1, 1936

By C. E. Wood, E. P. Barrett, T. L. Joseph

The United States Bureau of Mines has been studying the blastfurnace process for about ten years. An experimental furnace was developed by the Burcau in cooperation with the Minnesota School of Mines Experiment Station, University of Minnesota. Many data have been obtained and published.' Royster, Joseph and Kinney §(48) found that the particle size of ore had an important effect upon the blast-furnace process. Kinne(28) stated: Economy in blast-furnace practice depends largely upon efficient gas-solid contact in the shaft of the furnace. If efficient work is not done in the shaft, the hearth and bosh will not function properly. A condition may be readily imagined where the particles of ore in the shaft are so large that the time entailed in the descent of these materials into the bosh is not sufficient to permit proper reduction and preparation prior to the time the ore enters the bosh of the furnace. Another condition may be pictured where the density of theatock column and the flow of stock is such that the ore will take one course and the gas another. Both of these examples will result in insufficient contact between the gas and the ore. Unreduced ore will reach the hearth, and the gas which has not been efficiently oxidized will reach the stock line. The result is the use of an excess of carbon in the smelting process. It is obvious that fine ore particles occurring in the ore as charged, or formed in the furnace due to heat and mechanical action, place a definite limitation upon the efficiency of the operation. There is also an economic loss of fine material as dust. Effect of Size of Material Kinney reported (p. 83(29)) the reduction of iron oxides between planes at three furnaces as given in Table 1. The Chicago furnace was operated on Lake ores. Distribution of gas was not good and much of the charge passed into the hearth before the iron oxide was reduced. The Holt furnace was operated on coarse ore. Distribution of gas was fairly uni-

Jan 1, 1930

By F. B. Plummer, R. B. Newcome

The practice of introducing acid into oil wells to increase production of oil and gas has been in use since 1894, when it was first used in the Pennsylvania oil fields30.‡ It is only since 1928 that it has been used to any extent in the Mid-Continent18. The process has proved successful in increasing production, at least temporarily, in depleted oil fields where the producing formation is highly calcareous and where water drive is not too pronounced. In the Zwolle field in Louisiana, where the producing horizon is a chalk, increases of 100 per cent have been recorded25. In north-central Texas, where the oil is produced from the Marble Falls limestone, equally pronounced increases have resulted3. The production also in some fields yielding oil from quartz sand cemented with calcitc has been benefited. The evidence of actual increase in total recovery of oil, however, has been questioned by some engineers18. It has been pointed out that the results of the treatment of a well in a now district, where the process has never been tried out, can never be predicted with certainty, since other factors besides percentage of calcareous content of the oil sand play a large part in determining the success of the method. Numerous articles have been published on acid treatment and on the effects of acid on limestone1-35, yet very little has been written concerning experimental work on the actual effect of acid on capillary pores and larger oil-coated voids of oil sands. This is due partly to difficulties in duplicating field conditions in a laboratory and partly to the fact that the process has been carried out largely by contracting companies that have been unwilling to publish details of their results for fear of loss of business to competitors. The authors, using equipment developed to measure the radial permeability of oil-sand cores2', have developed a method of investigating the results of acid treatment which has enabled them to test numerous cores and to study in some detail the action of acid on the different types of rocks, particularly fine-grained rocks.

Jan 1, 1936

By Charles M. Ryder

In presenting this paper to the Institute I beg to mention, first, the results which I have obtained and the apparatus which I have employed, and to follow this with a brief description of the steps by which I hare perfected this process. My present mode of testing is as follows: I obtain, either from the furnace or from the finished product in any stage in which it may chance to be, a small test-piece, usually about 3/4 of an inch square by 3 1/2 inches in length. I place this test-piece upon the poles of an ordinary electro-magnet, for about one minute, and thus magnetize it to its extreme limit. I then place it upon an indicator (which I will shortly describe), on which indicator there is already placed a piece of steel of similar form which has been magnetized in the same manner, the percentage of carbon of this second piece being definitely known. I then, by means of a scale, which forms part of the indicator, marked in degrees of carbonization, read the exact percentage of carbon contained in the piece under examination. My apparatus consists of an ordinary electro-magnet, connected with a suitable battery of moderate power, by which I magnetize the pieces as before described, and of an indicator which consists of a magnetic needle suitably mounted or suspended, so that it is free to deviate a few degrees only from the zero point, and having a rest, which is used to check the vibrations when in use, and to support its weight when not in use. At a right angle to the natural position of the needle I have a scale about 3 feet long, the zero point of which coincides with the natural position of the needle. This scale is marked in each direction from the zero point in degrees of carbonization. The marking of the scale is in accordance with the following rule: Taking the carbonization of the steel as a basis, I maintain the same proportion between the squares of the distances on the scale as exists between the percentages of carbon in the steel, for instance, if .08 of

By Charles M. Ryder

IN presenting this paper to the Institute I beg to mention, first, the results which I have obtained and the apparatus which I have employed, and to follow this with a brief description of the steps by which I have perfected this process. My present mode of testing is as follows : I obtain, either from the furnace or from the finished product in any stage in which it may chance to be, a small test-piece, usually about 4 of an inch square by 3 1/2 inches in length. I place this test-piece upon the poles of an ordinary electro-magnet, for about one minute, and thus magnetize it to its extreme limit. I then place it upon an indicator (which I will shortly describe), on which indicator there is already placed a piece of steel of similar form which has been magnetized in the same manner, the percentage of carbon of this second piece being definitely known. I then, by means of a scale, which forms part of the indicator, marked in degrees of carbonization, read the exact percentage of carbon contained in the piece under examination. My apparatus consists of an ordinary electro-magnet, connected with a suitable battery of moderate power, by which I magnetize the pieces as before described, and of an indicator which consists of a magnetic needle suitably mounted or suspended, so that it is free to deviate a few degrees only from the zero point, and having a rest, which is used to check the vibrations when in use, and to support its weight when not in use. At a right angle to the natural position of the needle I have a scale about 3 feet long, the zero point of which coincides with the natural position of the needle. This scale is marked in each direction from the zero point in degrees of carbonization. The marking of the scale is in accordance with the following rule: Taking the carbonization of the steel as a basis, I maintain the same proportion between the squares of the distances on the scale as exists between the percentages of carbon in the steel, for instance, if .08 of

Jan 1, 1877

By H. G. Botset

ANY information that will increase the accuracy of our knowledge of the conditions prevailing in petroleum reservoirs should be of direct value in the determination of the proper operating technique as well as in the estimation of reserves and of ultimate production. The obvious method of obtaining this information is by studying a sample of the reservoir rock and its contents. In any such study, the problem of primary importance and maximum difficulty is that of getting the core to the surface in such a manner that its original fluid content is undis-turbed, which has so far proved to be an impossible task. Though it might be rash to say this will never be done, it is certainly safe to assume that a method for the recovery of a core at the surface in its undisturbed original state may not be developed in the immediate future, and certainly will not be forthcoming without a great deal of costly experimentation. Therefore any information that may be obtained that will help to correlate the state of a core (its fluid saturation) at the surface with its condition at the time it was drilled should be of value to the petroleum industry. The experiments described in this paper were undertaken with the purpose of determining, if possible, any relationship that might exist between the saturation of a core at the surface and its original fluid content. No consideration has been given to the question of contamina-tion by penetration of drilling water, since this problem has been exten-sively studied by other investigators. 1-3 Furthermore, it was regarded as being outside the scope of the present experiments, which were con-cerned only with the effect of pressure reduction upon the liquid content of cores. In an experimental study of this sort involving a large number of variables, accurate control of all factors is very important. The essen-tial and obvious procedure is to vary systematically one factor or condi-tion while keeping all the others constant, which necessarily involves a rather protracted and sometimes tedious experimental program.

Jan 1, 1939

By M. Muskat, H. G. Botset

Any information that will increase the accuracy of our knowledge of the conditions prevailing in petroleum reservoirs should be of direct value in the determination of the proper operating technique as well as in the estimation of reserves and of ultimate production. The obvious method of obtaining this information is by studying a sample of the reservoir rock and its contents. In any such study, the problem of primary importance and maximum difficulty is that of getting the core to the surface in such a manner that its original fluid content is undisturbed, which has so far proved to be an impossible task. Though it might be rash to say this will never be done, it is certainly safe to assume that a, method for the recovery of a core at the surface in its undisturbed original state may not be developed in the immediate future, and certainly will not be forthcoming without a great deal of costly experimentation. Therefore any information that may be obtained that will help to correlate the state of a core (its fluid saturation) at the surface with its condition at the time it was drilled should be of value to the petroleum industry. The experiments described in this paper were undertaken with the purpose of determining, if possible, any relationship that might exist between the saturation of a core at the surface and its original fluid content. No consideration has been given to the question of contamination by penetration of drilling water, since this problem has been extensively studied by other investigators.1-3 Furthermore, it was regarded as outside the scope of these experiments, which were concerned only with the effect of pressure reduction upon the liquid content of cores. In an experimental study of this sort involving a large number of variables, accurate control of all factors is very important. The essential and obvious procedure is to vary systematically one factor or condition while keeping all the others constant, which necessarily involves a rather protracted and sometimes tedious experimental program. The procedure adopted was essentially very simple, and consisted merely in filling a given core with fluid (gas and oil, gas and water, or

Jan 1, 1939

By M. Muskat, H. G. Botset

Any information that will increase the accuracy of our knowledge of the conditions prevailing in petroleum reservoirs should be of direct value in the determination of the proper operating technique as well as in the estimation of reserves and of ultimate production. The obvious method of obtaining this information is by studying a sample of the reservoir rock and its contents. In any such study, the problem of primary importance and maximum difficulty is that of getting the core to the surface in such a manner that its original fluid content is undisturbed, which has so far proved to be an impossible task. Though it might be rash to say this will never be done, it is certainly safe to assume that a, method for the recovery of a core at the surface in its undisturbed original state may not be developed in the immediate future, and certainly will not be forthcoming without a great deal of costly experimentation. Therefore any information that may be obtained that will help to correlate the state of a core (its fluid saturation) at the surface with its condition at the time it was drilled should be of value to the petroleum industry. The experiments described in this paper were undertaken with the purpose of determining, if possible, any relationship that might exist between the saturation of a core at the surface and its original fluid content. No consideration has been given to the question of contamination by penetration of drilling water, since this problem has been extensively studied by other investigators.1-3 Furthermore, it was regarded as outside the scope of these experiments, which were concerned only with the effect of pressure reduction upon the liquid content of cores. In an experimental study of this sort involving a large number of variables, accurate control of all factors is very important. The essential and obvious procedure is to vary systematically one factor or condition while keeping all the others constant, which necessarily involves a rather protracted and sometimes tedious experimental program. The procedure adopted was essentially very simple, and consisted merely in filling a given core with fluid (gas and oil, gas and water, or

Jan 1, 1939

By Charles White Merrill

Money is one of the most pervasive elements in human life. The compensation for a workman's daily efforts is expressed as a wage and is measured in money. What an individual may consume depends largely on his income which also is expressed in terms of money. If he would start an enterprise its size would be determined in large part by the amount of money available for capitalization and its success would be measured in net income expressed in money. In short, the most widely used common de- nominator for comparing merchandise, real property, jobs, enterprises, gross national product, or personal success is money. Despite this use of money by almost everyone past infancy to express his appraisal of the innumerable values he sees around himself, the complexity of the device called money makes its nature and workings a mystery to most users. Some of the difficulty in understanding money results from the fact that it has three distinct but interrelated functions: (1) a medium of exchange, (2) a unit of account, and (3) a store of value. In many statements about money the discussion moves from one function of money to another without the speaker or the listener recognizing the changes. For example, the housewife says "We took the money we had saved up to make the down payment and after twelve monthly payments the television will be ours." When this housewife spoke of "saving up the down payment" she referred to money in its function as a store of value; when she spoke of "the down payment" she was using money as a medium of exchange; and when she referred to the "monthly payments" she spoke of money as a unit of account. Another cause of confusion in understanding money is its paradoxical nature in that it represents both the power to produce and the power to consume. For example, when the rich uncle dies one nephew may regard his inheritance as an opportunity to buy a farm and leave the ranks of the wage earners to become an independent producer, whereas the other nephew may regard his portion as the means of living in complete leisure as a pure consumer.

Jan 1, 1964

By Henry S. Mackay

The interesting paper recently submitted by Messrs. Tobelmann and Potter1 shows that chemical problems have developed which are of great interest in this new and important branch of metallurgy. Those who realize what a process of this kind really involves will agree that it deserves a better name than '(leaching process." The word leaching conveys the idea that the copper is simply leached out of the ore with acid and then precipitated on iron; the chemistry of such a process would be of little interest. As, however, during the first year's operation of this plant 24,400,532 lb. (11,067,837 kg.) or about two-thirds of the produce, was electrolytic copper, while 7,992,033 lb., or about one-third, was cement copper, it would seem more appropriate to term the process electrochemical. It further appears, from the particulars given, that efforts have been made to have the entire production in the form of electrolytic copper. This could be done if the chemistry of the problem were kept in balance, so that it would not be necessary to discard any solutions that carried copper and acid of commercial value. A process, such as that under consideration, in which the copper is precipitated from solution by electrolysis, the solvent being at the same time regenerated, is one that requires special chemical and electrochemical knowledge and experience if all the copper in solution that has been extracted from the ore is to be successfully and economically produced as electrolytic copper. The object of this paper is to discuss, from the practical and theoretical standpoints, the chemical and electrochemical problems involved in the working of a process of this kind, and which must be solved to keep it in chemical and electrochemical equilibrium. In such a process, if the chemical balance is maintained, a solution can be used alternately as a solvent for the copper in the ore and as an electrolyte of high efficiency for the precipitation of the copper. To maintain the chemical equilibrium and so attain this result, the process must be so controlled that the solu-

Jan 1, 1921

By H. M. Davis, J. H. Keeler

Densities of SAE 1020 (I) and ingot iron (II) decreased with cold rolling to minima at 60 pct reduction, whereas high-purity iron (III) was unaffected. I recovered promptly with annealing; II, sluggishly and incompletely. Hydrogen occlusion of III or II was barely affected by 60 pct cold reduction, but that of I was increased a hundredfold. IT has been reported of iron that its density is decreased and its occlusive capacity for hydrogen is increased by cold work. One of the most interesting aspects of each of these properties is that the changes brought about by cold work are not necessarily eliminated by annealing and recrystallization. Yet recrystallization is generally accepted as restoring to their original condition the properties or characteristics altered by cold work. A number of investigators have reported a decrease in density with cold reduction. Two1, 2 have shown that annealing after cold reduction may not return the density to its original value. It has been suggested' that cracks or flaws in inclusions produced during cold drawing contribute to the lowering of the bulk density of the metal. Extremely high-purity copper has been reported as not exhibiting a density decrease with cold reduction. On the other hand, calculations' indicated that grain distortion by itself can produce expansion of the order of magnitude of the changes observable. Maier" showed that both the density of iron and that of copper passed through a minimum with increasing cold reduction. Although much information is available on the subject of hydrogen in steel0, 7 and it is well known that plastic deformation of a metal may increase its occlusive capacity,8-12 most of the reports pertain to charging the metal with hydrogen by cathodic deposition or with acid. Darken and Smith,'" who employed acid charging, emphasized the great influence of cold work on the occlusive capacity of iron for hydrogen and showed the inability of a prolonged high-temperature annealing treatment to restore the occlusive capacity of cold-worked steel to the value exhibited in the hot-rolled condition. It has been reportedm that an "endothermic" metal*

Jan 1, 1954

By William H. Radford

Having worked some rather lorn--grade gravel during the past season at a small profit, I give the actual figures, in the hope that other mining engineers interested in this line of work may be thereby induced to do the same, in order that we may all get more data on this little-ventilated subject. The property here referred to is situated in one of the northern counties of California, where hydraulic mining is still permitted by the courts. The water-right belonging to the mine is a good one, furnishing water during about nine months, whenever there is an average rain-fall, and a fair proportion of the precipitation is in the form of snow. The ditch, about 11 miles in length, is cared for during the rainy months by two men, and during the rest of the year by one; and the water cost last season, delivered at the mine, 0.69 cent per miners' inch. The season commenced in November, 1899, and ended the last of July, 1900. During this time, 655,657 miners' inches (an inch equals 1728 cu. ft. in 24 hours) of water were used for piping, and for sweeping the bed-rock at the end of the season. From actual surveys, this amount of water washed down 1,251,399 cu. yds. of material, consisting of pay-gravel lying on the bed-rock, and varying in thickness from a few inches to 8 ft., and practically barren top-material, consisting of mountain slide, carrying considerable broken rock, clay, and soil. The banks varied in height from 50 to 130 ft., the average height being 63 ft. The grade of the sluices was 7 in. to 12 ft., the boxes being paved with block-riffles 12 in. deep. Long bed-rock cuts extended from the heads of the sluices to within a few feet of the banks, and were kept practically to grade as the work advanced. At first, electric drills were used on this work; hut as it was found that heavy blasting shattered the rock too much, and caused slips, these drills were

Jan 1, 1902

This fund was established in 1929 for support of research and especially refers to non-ferrous mining and metallurgy. It is administered under the Board by a committee consisting of the President and Secretary and three members selected by the Board. HOWE MEMORIAL LECTURE The Howe Memorial Lecture, in memory of Henry Marion Howe, Past President of the Institute, was authorized in April, 1923, as an annual address to be delivered by invitation under the auspices of the Institute by an individual of recognized and outstanding attainment in the science and practice of iron and steel metallurgy or metallography, chosen by the Board of Directors upon recommendation of the Iron and Steel Division. The following were the Howe lectarers for the years indicated: Albert Sauveur—1924 Bradley Stoughton—1927 John A. Mathews—1925 Henry D. Hibbard—1928 William Campbell—1926 John Howe Hall.—1929 JOINT ACTIVITIES The Institute conducts jointly with the American Society of Civil Engineers, American Society of Mechanical Engineers, and American Institute of Electrical Engineers, certain activities as listed below, and is joint owner with them of certain properties. United Engineering Society This is a corporation organized by the American Institute of Mining Engineers, American Society of Mechanical Engineers, and the American lnstitute of Electrical Engineers, to hold the title and administer the property at 29 West 39th St. In 1916, the American Society of Civil Engineers was admitted, and each society now has an equal one-fourth interest in the ownership, occupancy, and administration of the building. . The cost of this property has been over two million dollars. A. I. M. E. representatives are: Arthur S. Dwight, John V. N. Dorr and H. A. Guess. Alfred U. Flinn, Secretary, 29 West 39th St., New York City. Engineering Foundation This is a fund established by the United Engineering Society in 1915 with a gift of $200,000 from Ambrose Swasey. Subsequent gifts had increased the fund to about $620,000 on March 1, 1929. The income of the fund is used to further research in science and engineering and to advance the profession of engineering and the good of mankind. A research project in alloys of iron is being conducted in

Jan 1, 1929

By O. H. Hahn

I have lately had occasion to conduct a campaign at the works of the Empire City Company, in Railroad District, Elko County, Nevada, which, if not highly satisfactory, was at least very interesting in a technical point of view, and which I therefore think worthy of communication to the Institute. The lead ores in this district occur in lenticular masses along and near the contact of crystalline limestone with a dioritic porphyry, and consist of argentiferous carbonate of lead and galena, the latter occurring in solid blocks, or in ribbons running through the limestone. Associated with these are silicate, carbonate, and suboxide of copper, and brown and calc-spar. Adding to this, that the proportion of galena in the ore is small, and that no iron pyrites exists in the district, it is at once evident that the ore-mixture is difficult to treat. For a successful reduction by smelting, it would be necessary to introduce into the charge: 1. The proper quantities of sillphur-bearing ingredients, to effect a complete separation of copper and lead; and, 2. Sufficient silica and iron oxide, to form with the lime and magnesia of the ore, a slag of the required fluidity. The first condition could be fulfilled only very imperfectly, there being no iron pyrites in Railroad, nor in the surrounding districts. The nearest occurrence is in Battle Mountain, whence a supply could not be procured in time. The second condition, i. e., the addition of iron ore and quartz, was easily complied with, there being an abundance of these materials in the vicinity. The furnace of the Empire City Company, is a small shaftfurnace, with an area of hearth of six square feet, and is supplied with blast by a NO. 4 Root blower. In spite of this small size the furnace smelted during this campaign, which lasted 31 days, an average of 28 tons of ore, and 13 tons of fluxes, together 41 tons of charge, per twenty-four hours. The following tables give the complete data in regard to the smelting process, and the results obtained: