Search Documents

By John Dresser

General THE controlling supply of asbestos for the world is obtained from southern Quebec, 150 miles or less north of the international boundary line between Canada and the United States, and about 75 miles south of the city of Quebec. The principal production is furnished by eight mines, seven of which occur within a distance of 6 miles, but there are also several smaller properties in the vicinity. The industry was begun in a small way some 35 years ago and has advanced more or less regularly ever since. The annual production now exceeds 100,000 tons and its value is about $3,000,000. It represents over 80 per cent. of the world's production. History Asbestos has been known in the eastern townships of Quebec since 1847, when attention was called to it in an official report by Sir William Logan, the first Director of the Geological Survey of Canada, but it was not until 30 years later that it came into commercial importance. The largest deposits, those of Thetford and Black Lake, were found in 1877 during the construction of the Quebec Central Railway. Work was begun upon them almost at once and has been continued ever since. The Danville mine, the next largest producer, was opened in 1879, and the slip-fiber deposits of East Broughton were located shortly afterward. For the first 15 years only the "crude" asbestos was recovered; that is, fiber long enough to be extracted by hand cobbing. Although this is still a valuable part of the production, it is now a relatively small part of the total output.

Jan 9, 1914

By George A. Moore

A recent survey of existing analytical results, and an attempt to correlate them with each other and with the known history and behavior of the samples, indicated that none of the commonly applied methods could be considered established as intrinsically reliable. It was. therefore, desired to attempt to establish the reliahility of some one method by external evidence. If this were to be accomplished, other methods could then be evaluated in terms of the method establibhed. The correct method was accordingly to be chosen without regard for cost, speed, or convenience; with the requirements for routine application to be reserved for 1ater consideration. The method of total combustion was chosen and submitted to a limited number of tests against primary standard samples. Considerable experimental difficulty was encountered, indicating that additional work on the experimental arrangements is desirable. While the work to (late by no means represents a completed investigation, it is helieved that the combustion method is basically sound and that its development should be continued. Choice of Method Of the several available methods, mechanical disintegration. electrochemical methods'2'3 modifications of the Sieverts experiment,% and vacuum fusion, were all judged to contain one or more factors of un- certainty not at present completely cvaluated or suhject to complete control. These methods, therefore, were considered currently unsuitable for referee purposes. Solid evolution was considered to be of doubtful significance when conducted in the alpha range. A reasonable chance for a true analysis was found for evolution in the gamma range. Preliminary tests have indicated a very slow rate for evolutioll from gamma iron. indicating a running time of possibly 100 hr. for a one-centimeter sample. Difliculty in distinguishing such slow. evolution from blank gas was anticipated, hence the method was not consitlerctl the most suitable for the present purpose. The combustion method was evaluated as being most sound on fundamental principles. The only important unknown would be to determine that the iron oxide formed did not occlude water at the tcmperaturv of the combustion.with the odvious precautions of using a sound and clean specimen, providing a system sufficiently tight to give acceptable blanks in longtime runs, and providing a suficicntly sensitive measuring system, reasonable, precise, and truthful analytical results could be logically expected. Apparatus The equipment as originally operated is shown in Fig. I, and the glassw-are in its latest modification in Fig. 2. The sulphuric acid drier and small safety tube in the upper right of Fig. I were replaced by a KOH drier and combined manometer safety tube, to permit operation at reduced

Jan 1, 1945

By M. Muskat

Calculations are reported on the differential sensitivity of the updip invasion of oil strata of varving permeability to the driving pressure differential. It is assumed that the water-oil interfaces advance with sharp fronts, or that the microscopic displacement efficiency is independent of rate and capillary pressure effects. It is found that, under such conditions, limitations of withdrawal rates will not greatly inhibit the "fingering" and bypassing tendency through high permeability strata unless the differential fluid head across the original oil column is of the order of or exceeds about 80 per cent of the driving pressure differential. In practice, such restrictions will be feasible only for oil reservoirs and aquifers of high permeability and dip, but may develop automatically under combined gas injection and water drive operations. INTRODUCTION A commonly expressed view regarding the intrusion of edge-waters into oil producing formations is that the geometry of such advance is rate sensitive. Specifically, it has been suggested that high rates of advance, stimulated by rapid withdrawals, will lead to "fingering" and an irregular type of invasion, whereas at low withdrawal rates the water encroachment will be more uniform. Two factors tend to support this view. One is the resultant effect of capillary pressure and gravity gradients in the displacement processes' involved in water intrusion, which are magnified at low rates of flow so as to improve the recovery efficiency. The other is the direct retarding effect of the rising water head as it advances upslope into the producing area. Capillary pressure forces give rise to a rate sensitivity of the oil recovery by water displacement in uniform strata as well as differential effects in non-uniform formations. These are basically independent of the effect of gravity and would also occur in horizontal beds or when the oil and water have the same density. Unfortunately, however, the fundamental equation describing the displacement process under the action of capillary pressures can be solved only by numerical or graphical procedures, and moreover the solutions are sensitive to the character of the capillary pressure and relative permeability curves.* On the other hand, the direct effect of gravity can be given a formal analytical solution if the simplifying assumption is introduced that the water advances with sharp fronts in the individual uniform strata. It depends on the absolute permeabilities of the water invaded zones and hence results in a rate sensitivity of the differential invasion in stratified media. Although a tieatment of this factor alone will not give a complete evaluation of the effect of rate on water intrusion in non-uniform pays, it should provide at least a semiquantitative measure of the sensitivity of "fingering" to withdrawal rate. Such a treatment will be presented in the following sections. GENERAL THEORY The basic element of the theory is the history of water advance updip in a uniform stratum (Fig. 1). In contrast to the assumption of constant flow rate, generally made in the analysis of displacement processes, we shall assume here that

Jan 1, 1951

By M. Muskat

Calculations are reported on the differential sensitivity of the updip invasion of oil strata of varving permeability to the driving pressure differential. It is assumed that the water-oil interfaces advance with sharp fronts, or that the microscopic displacement efficiency is independent of rate and capillary pressure effects. It is found that, under such conditions, limitations of withdrawal rates will not greatly inhibit the "fingering" and bypassing tendency through high permeability strata unless the differential fluid head across the original oil column is of the order of or exceeds about 80 per cent of the driving pressure differential. In practice, such restrictions will be feasible only for oil reservoirs and aquifers of high permeability and dip, but may develop automatically under combined gas injection and water drive operations. INTRODUCTION A commonly expressed view regarding the intrusion of edge-waters into oil producing formations is that the geometry of such advance is rate sensitive. Specifically, it has been suggested that high rates of advance, stimulated by rapid withdrawals, will lead to "fingering" and an irregular type of invasion, whereas at low withdrawal rates the water encroachment will be more uniform. Two factors tend to support this view. One is the resultant effect of capillary pressure and gravity gradients in the displacement processes' involved in water intrusion, which are magnified at low rates of flow so as to improve the recovery efficiency. The other is the direct retarding effect of the rising water head as it advances upslope into the producing area. Capillary pressure forces give rise to a rate sensitivity of the oil recovery by water displacement in uniform strata as well as differential effects in non-uniform formations. These are basically independent of the effect of gravity and would also occur in horizontal beds or when the oil and water have the same density. Unfortunately, however, the fundamental equation describing the displacement process under the action of capillary pressures can be solved only by numerical or graphical procedures, and moreover the solutions are sensitive to the character of the capillary pressure and relative permeability curves.* On the other hand, the direct effect of gravity can be given a formal analytical solution if the simplifying assumption is introduced that the water advances with sharp fronts in the individual uniform strata. It depends on the absolute permeabilities of the water invaded zones and hence results in a rate sensitivity of the differential invasion in stratified media. Although a tieatment of this factor alone will not give a complete evaluation of the effect of rate on water intrusion in non-uniform pays, it should provide at least a semiquantitative measure of the sensitivity of "fingering" to withdrawal rate. Such a treatment will be presented in the following sections. GENERAL THEORY The basic element of the theory is the history of water advance updip in a uniform stratum (Fig. 1). In contrast to the assumption of constant flow rate, generally made in the analysis of displacement processes, we shall assume here that

Jan 1, 1951

By Warren E. Wilson

PRESENT-DAY design of launders is essentially an art depending to a marked degree upon the experience of the designer, whose problem is that of determining the dimensions of a conduit that will transport the pulp within the physical limitations of the plant and in the most economical manner. This paper has been prepared in an effort to place launder design upon a more scientific basis. A method is developed from elementary principles and presented in a form that may be used directly by the designer in determining launder dimensions.. The equations that are developed are believed to represent an advance over older ones, in that they give due consideration to all the pertinent variables, either including them in the analysis or showing that they may be neglected within the limits of applicability of the equations. Experimental data from several sources are used in evaluating the coefficients that are not determined in the mathematical analysis. On the basis of the material presented, it is concluded that launders may be designed with a much greater degree of accuracy than previously believed possible, when due consideration is given to all the factors involved in the problem. However, a great deal of work still remains to be done in the laboratory before a complete answer to all the questions in launder design can be made available. HISTORY OF LAUNDER DESIGN Among the references1-11 are cited accounts of many experiments that have been conducted in an effort to advance the knowledge of the flow of liquid-solid mixtures in flumes and pipes. With three notable exceptions, this work was carried on in such a manner that the results have limited value in solving the general problem, since not all the pertinent variables were measured and controlled. The exceptions are found in the works of Blue,6 Gilbert,7 and Blatch,11 who exercised great care in controlling and measuring all the significant quantities involved in the experimentation. It is notable that much of the work done by men directly connected with the mineral industries1-4 lacks somewhat in completeness, owing apparently to preconceived notions concerning the factors that determine the flow. For example, many measurements on flow in pipes and flumes carrying liquid-solid mixtures determined only the slope and percentage of solids, with no mention of size of particles, depth of flow, roughness of channel or specific gravity of solids. Material in current handbooks8,9 and textbooks is based largely on the experimental work cited above. Although most discussions of the topic-include statements that the results to be obtained by using the data presented are limited by the fact that all variables have not been considered, it is

Jan 1, 1943

By James R. I. Henagan, William O. Crego

The Mamou Field, located in Evangeline Parish, La., is an elongated anticlinal structure on the downthrown side of a major east-west fault with oil and gas production from the upper part of the Wilcox formation. Two main producing horizons occur at an approximate depth of 11,500 ft and have been designated the Morein sand and the Deshotels sand. The upper sand (Morein) had an original bottom-hole pressure of 6,788 psig, which is some 1,500 psi above the normal pressure for that depth. Oil production with high gas/oil ratios and fluid analyses giving high shrinkage factors prompted a study of the reservoir in its early stages. The results indicated a closed reservoir producing under solution gas drive with low expected ultimate oil recovery. The early study of the Wilcox formation and its contained hydrocarbons resulted in the presentation of the data to the Department of Conservation of the State of Louisiana. with suggestions for field rules and a request for permission to inject extraneous water into the Morein sand. The water injection plans eventually led to complete unitization of working and royalty interests, to the construction of a gasoline plant, and to a central tank battery installation for the field. Deshotels sand wells were reworked to the Morein sand, and the water injection system was installed and ready for continuous operation in the early part of 1949. The injection of water was started in time to arrest the bottom-hole pressure decline at or near the bubble-point pressure. This injection was calculated to increase the ultimate recovery and to conserve natural resources. Pressure maintenance, the extraction of LPG products, and the sale of residue gas (early 1950) represent an attempt to produce an oil field with utmost efficiency. INTRODUCTION The two principal Wilcox oil horizons in the Mamou Field are the Morein sand and the Deshotels sand, occurring at 11,500 ft and 11,700 ft subsea, respectively. Minor oil production has been encountered in Morein stringer sands. (Fig. 1.) This paper deals only with the Morein sand, which is blanket over the Mamou Field. It is, however, segmented by the northwest-southeast "E" fault as shown in Fig. 2. The west segment is the area involved in the water injection pressure maintenance program. To date the east segment has operated largely under the influence of a strong water drive. The paper presents (1) a brief history of field development, (2) a resumé of reservoir conditions which led to the decision to inject extraneous salt water into the principal producing horizon, and (3) a summary of reservoir analysis and performance. FIELD DEVELOPMENT The Mamou Field is located in Evangeline Parish, La. The discovery well (J. B. Morein No. 1, now Unit No. 5) was completed in December, 1945, after penetrating 200 ft into the Wilcox formation. Initial production from the Morein

Jan 1, 1951

By James R. I. Henagan, William O. Crego

The Mamou Field, located in Evangeline Parish, La., is an elongated anticlinal structure on the downthrown side of a major east-west fault with oil and gas production from the upper part of the Wilcox formation. Two main producing horizons occur at an approximate depth of 11,500 ft and have been designated the Morein sand and the Deshotels sand. The upper sand (Morein) had an original bottom-hole pressure of 6,788 psig, which is some 1,500 psi above the normal pressure for that depth. Oil production with high gas/oil ratios and fluid analyses giving high shrinkage factors prompted a study of the reservoir in its early stages. The results indicated a closed reservoir producing under solution gas drive with low expected ultimate oil recovery. The early study of the Wilcox formation and its contained hydrocarbons resulted in the presentation of the data to the Department of Conservation of the State of Louisiana. with suggestions for field rules and a request for permission to inject extraneous water into the Morein sand. The water injection plans eventually led to complete unitization of working and royalty interests, to the construction of a gasoline plant, and to a central tank battery installation for the field. Deshotels sand wells were reworked to the Morein sand, and the water injection system was installed and ready for continuous operation in the early part of 1949. The injection of water was started in time to arrest the bottom-hole pressure decline at or near the bubble-point pressure. This injection was calculated to increase the ultimate recovery and to conserve natural resources. Pressure maintenance, the extraction of LPG products, and the sale of residue gas (early 1950) represent an attempt to produce an oil field with utmost efficiency. INTRODUCTION The two principal Wilcox oil horizons in the Mamou Field are the Morein sand and the Deshotels sand, occurring at 11,500 ft and 11,700 ft subsea, respectively. Minor oil production has been encountered in Morein stringer sands. (Fig. 1.) This paper deals only with the Morein sand, which is blanket over the Mamou Field. It is, however, segmented by the northwest-southeast "E" fault as shown in Fig. 2. The west segment is the area involved in the water injection pressure maintenance program. To date the east segment has operated largely under the influence of a strong water drive. The paper presents (1) a brief history of field development, (2) a resumé of reservoir conditions which led to the decision to inject extraneous salt water into the principal producing horizon, and (3) a summary of reservoir analysis and performance. FIELD DEVELOPMENT The Mamou Field is located in Evangeline Parish, La. The discovery well (J. B. Morein No. 1, now Unit No. 5) was completed in December, 1945, after penetrating 200 ft into the Wilcox formation. Initial production from the Morein

Jan 1, 1951

By A. L. Mular

The flotability of crushed zinc oxide pellets which were doped to produce more n-type or less n-type (more p-type) properties was studied with a Halli-mond tube. Flotation data are presented to show that the pH at which 50% recovery occurs and the collector concentration for 50% recovery depends upon the concentration of doping agent added substitu-tionally for zinc in zinc oxide. The time of sintering of pellets has a slight effect on flotation behavior. A speculative model is proposed to explain the observed behavior in light of the fact that zinc oxide is a semiconductor and has a space charge region at the surface. Experimental verification is necessary before the proposed model can be established as correct. In recent years, the attachment of flotation reagents to minerals has been shown to depend upon the behavior of an electrical double layer which exists in the liquid near the mineral-liquid interface.' Thus, a mineral placed in water will undergo a surface re-arrangement, most likely be preferential dissociation of lattice atoms or by surface adsorp-tion-desorption reactions, to form a dissociation electrical double layer with the solution. Among the many factors which influence adsorption processes, the past history of the mineral itself is one of the most important. Because of trace impurities, minerals from different localities may exhibit marked differences in flotation behavior. This is not unexpected, since investigators who have studied the detailed structure of the double layer's3 have known for some time that the impurity content of many minerals may exert strong influence on double layer variables. For this reason, their studies were usually made with minerals of high purity. The precise relationship between impurities in a mineral and double layer parameters such as capacity and electrostatic potential has been obscure. However, impurities in a semiconductor type mineral which is in contact with a solution have been recently shown to produce changes in the properties of a space charge layer which extends into the bulk of the semiconductor to a distance of one micron or more.4 The double layer is influenced by the space charge layer, whose origin is best discussed in terms of the band theory of solids. A qualitative description of the behavior of impurities in the bulk of a semiconductor, from a chemical point of view, is useful at this point. Briefly, impurities or defects (lattice vacancies, interstitials, etc.) in semiconductors such as PbS, ZnS, FeS2, Cu2S, NiS, NiO, Fe2O3, ZnO, CdS, MnO2 and many others, behave somewhat like acids or bases in water. For example, water dissociates into hydrogen and hydroxyl ions according to

Jan 1, 1965

By Charles C. Rodd

PRIOR to 1938, proration procedure in Kansas required the physical testing of wells in order to set up a basis for allocating production. Subsequently the use of liquid-level data and bottom-hole pressure data was authorized on certain types of wells as a basis for calculating well capacities, thereby permitting wells to be tested at low rates and with small volumes of production. This paper gives some attention to the equipment used for obtaining liquid-level data but in general it is devoted to the theoretical and physical factors involved in well testing by drawdown methods. These tests are divided into two classifications: (1) liquid-level data used directly to calculate capacities, and (2) liquid-level data and liquid-level measuring equipment used in connection with other data to determine bottom-hole pressure. Equations and calculations for both types of tests are shown. Well capacities calculated from fill-up data have not been used generally but offer a simple means of testing some wells. Theoretical factors and calculations for such tests are shown. IN the state of Kansas, proration laws required that the "ability of a well to produce" be given consideration in state allocation orders and for many years this was the only factor used in prorating the allowed oil. The "ability of a well to produce" was the quantity of oil that could be obtained from a well in a prescribed period, usually 24 hr. Early in the history of State-regulated proration, Kansas operators realized that, unless some restriction were placed upon equipment, the competition between producers to obtain large well "potentials" might result in a race to install the largest pumping equipment. Consequently, restrictions were placed upon the size of tubing and length of pump stroke that could be used in pumping wells during potential tests. Later, restrictions were placed also upon the size of tubing and chokes that could be used in flowing walls. Despite the restriction set-up, better pumping equipment was designed and installed, pumps were improved, and various devices were invoked to obtain high rates of production for short periods of time. By 1937 pumping cycles of forty to forty-five 54-in. strokes per minute were not uncommon, and numerous wells had produced at the rate of 3500 bbl. per day for short periods. Such production was far beyond any rate that could be long sustained. Equipment necessary to take "potentials" was several times larger than that needed for normal producing purposes, and repairs and replacements required by the high pumping speeds were excessive. Also, many operators were beginning to suspect that the high rates of production maintained during "potential" tests were conducive to early water encroachment. By 1938 large-scale physical testing of wells in Kansas ended, the use of the bottom-hole pressure gauge had become common, engineers and operators were becoming familiar with the term "productivity index," and bottom-hole pressure was being used as a factor in allocation in many areas. There were many drawbacks, however, to large-scale use of

Jan 1, 1942

By Howard Talbot

THE history of the development of the strip in- dustry, mentioned in this paper, was covered in considerable detail by Stephen Badlam in his paper presented. before the American Iron and Steel Institute at its meeting in New York last October. The description of progress in rolling strip there out-lined will be found good reading by anyone interested in the subject. Quoting from Mr. Badlam's paper, "For practically thirty years, we find no record of the use of the backing-roll principle, until in 1916 the Lukens Steel Co., Coatesville, Pa., put in a 206-in. plate mill of the four-high type. This was a reversing mill with two 32-in. working rolls and two 50-in. backing rolls and is today making the widest and heaviest plate made anywhere in the world." The functioning of this mill, though rolling hot plate, is, on account of the extreme width and thinness of plate rolled, quite comparable to the rolling of wide strip either hot or cold and was a considerable factor in demonstrating the marked advantages available with the four-high or backing-roll mill for thin accurate rolling. As the writer has brought out, a demand for a product, the rolling of which required the character-istics of the backing-roll mill, was broached by the In-ternational Nickel Co. This resulted in an inquiry of March, 1924, for the building of a mill capable of cold-rolling wide nickel and monel metal sheets or strip, as mentioned. It may be of some interest to note, that whereas the .six-roll cluster mill with plain bearings was built for this installation, the mill designed by the United En-gineering and Foundry Co. for this inquiry was of the four-high type with roller bearings on the backing-roll necks, being essentially the same design as the four-high roller-bearing mill built in 1925 for the Rome Brass & Copper Co. This Rome mill, to quote again from Mr. Badlam's paper, "fulfilled every requirement, and was the model on which succeeding mills of this type were built."

Jan 5, 1928

By Walter Miller

During the second year of America's active ia in the war the inain objectives of the petroleum-refining industry were again to provide the four most important product needs for war: 100-octane aviation gasoline, toluene for T.N.T. production, high-quality lubricating oils for the needs of aviation and the armed forces, and petroleum chemicals for synthetic rubber manufacture. All other materials supplied by the petroleum industry took an inferior priority ranking, depending on the degree of essentiality. To accomplish the above objectives the industry initiated and carried on a building program during 1942 and 1943 which will put those two years down in petroleum-refining history as the greatest construction years of all time, a record which will hold for decades to come. Led by an estimated total of $ 900,000,000 going into 100-octane and contributory plant investment, it is easy to picture a total of two billion dollars and more going into additional refining-industry plant investment during 1942 and 1943, most of it privately paid for, but a substantial part covered by R.F.C. Government money financing. Some of the new plants will not be completed until 1944, but a large proportion of the program was finished and put into operation, adding substantially to the output of the four principal products during 1943- lne most important and spectacuiar activity of the refining industry is of course the 100-octane gasoline program necessitated by the fact that nearly 90 per cent of the requirements of the United Nations is being furnished by the United States. Recent P.A.W. figures mention $goo,-ooo,ooo as the cost of the construction looking to increasing the output of this all-important munition. Thirty-four major plants have been completed, 11 of them during the last quarter of the year. Thirty-eight more will be completed and put into operation during the first four or five months of 1944. Twenty-two additional plants authorized during 1943 are already well under way and scheduled for production late in 1944. Early in 1942 the aim was to treble the capacity for making 100-octane gasoline then existing; later, plans were to make it five times as great, to match the increased warplane building program; and toward the end of the year the sights had been set at a still higher but unannounced target, representing six to seven times the early 1942 figure. Comparative figures issued at the end of 1943 enable one to guess a program by the middle of 1944 of eight to nine times the former production, with an ultimate production in 1944 of eleven or more times the early 1942 output. It became obvious in 1943 that building of new units would be materially slowed because of delay in getting construction materials and that they would reach operation at considerably later dates than

Jan 1, 1944

By Walter Miller

During the second year of America's active ia in the war the inain objectives of the petroleum-refining industry were again to provide the four most important product needs for war: 100-octane aviation gasoline, toluene for T.N.T. production, high-quality lubricating oils for the needs of aviation and the armed forces, and petroleum chemicals for synthetic rubber manufacture. All other materials supplied by the petroleum industry took an inferior priority ranking, depending on the degree of essentiality. To accomplish the above objectives the industry initiated and carried on a building program during 1942 and 1943 which will put those two years down in petroleum-refining history as the greatest construction years of all time, a record which will hold for decades to come. Led by an estimated total of $ 900,000,000 going into 100-octane and contributory plant investment, it is easy to picture a total of two billion dollars and more going into additional refining-industry plant investment during 1942 and 1943, most of it privately paid for, but a substantial part covered by R.F.C. Government money financing. Some of the new plants will not be completed until 1944, but a large proportion of the program was finished and put into operation, adding substantially to the output of the four principal products during 1943- lne most important and spectacuiar activity of the refining industry is of course the 100-octane gasoline program necessitated by the fact that nearly 90 per cent of the requirements of the United Nations is being furnished by the United States. Recent P.A.W. figures mention $goo,-ooo,ooo as the cost of the construction looking to increasing the output of this all-important munition. Thirty-four major plants have been completed, 11 of them during the last quarter of the year. Thirty-eight more will be completed and put into operation during the first four or five months of 1944. Twenty-two additional plants authorized during 1943 are already well under way and scheduled for production late in 1944. Early in 1942 the aim was to treble the capacity for making 100-octane gasoline then existing; later, plans were to make it five times as great, to match the increased warplane building program; and toward the end of the year the sights had been set at a still higher but unannounced target, representing six to seven times the early 1942 figure. Comparative figures issued at the end of 1943 enable one to guess a program by the middle of 1944 of eight to nine times the former production, with an ultimate production in 1944 of eleven or more times the early 1942 output. It became obvious in 1943 that building of new units would be materially slowed because of delay in getting construction materials and that they would reach operation at considerably later dates than

Jan 1, 1944

By Michael A. Zappia

INTRODUCTION The San Manuel mine of Magmacopper Company is located approximately 72 km northeast of Tucson, Arizona. The mine, concentrator, smelter, electrolytic refinery and continuous rod casting are located on the west side of the San Pedro River valley. Ore Production: 58 1W mtpd Production To Date: Over 340 000 000 mt since 1956. Ore Grade: 0.70% net sulfide cu. As conceived at the present time, the San Manuel ore body is the lower half of what was originally an elliptical (In cross sect ion) cylinder same 2400 m long with major and minor cross sectional axes of 1500 m and 760 m. After emplacement, the cylinder was diagonally sliced along its long dimension by the San Manuel fault, which separated it into halves, moving the upper half same 2500 m down dip and bringing a wedge-shaped blanket of tertiary conglomerate into position over the lower segment of the cylinder. The lower segment is the San Manuel ore body. The upper part, moved down dip, is the Kalamazoo ore body. Originally, these were one ore body. The San Manuel ore body is a structurally weak and highly fractured quartz monzonite, the principal ore minerals being chalcopyrite, with small amounts of molybdenite. The present mining method is full gravity diagonal retreat panel caving by block. This is shown on Figure 2 , (Block Sequence 56, 57, 58, 59 --on the following page.) The ore mined is hoisted to the surface for transportation to the concentrator. BLOCK CAVING MINING SEQUENCE HISTORY The San Manuel mine was planned and developed as a full gravity block caving mine. It continues as a full gravity block caving mine. Since its initial start, the major changes in mining have been in the areas of ground support, rate of draw and undercut sequence. Ground weight resulting from block caving plays a dual role. It can cause extensive damage to ex- traction openings, yet it is necessary to break the ore into easily handled size. The ground- weight problem resolves itself into finding ways to make it manageable. The initial early ground support in the production areas consisted of timber sets and various combinations of steel and timber sets. This sup- port system proved unsatisfactory and a new support system utilizing concrete was developed. Concrete support, 30 cm to 45 cm thick, proved satisfactory. Rates of draw were experimented with. A draw rate of 45 cm to 61 cm (32 to 45 mt) per draw point per day was determined as optimum in con- trolling ground weight. Undercut sequence or mining sequence was recognized as a major contributing factor to ground weight. This is the most difficult factor to change. The lead time from primary development to undercut can be as much as two years. Initial Checkerboard Pattern The initial undercut sequence was in a checker- board pattern (Figure 2). Blocks Sequence 1, 2, 3, 4, 5, 6--next page.

Jan 1, 1981

By Paul Billingsley

CERTAIN adequately developed mining districts give complete three-dimensional patterns of ore bodies as clusters rising from roots in basement rocks with details controlled by structure of cover rooks. Examples are Goodsprings, Tintic, Bisbee, Leadville, Hedley, Eureka, Ely and Goldfield. In these and others the controlling structures in both basement and cover rock are elements of the neighboring regional structure and have been produced by rock movements in harmony with continental adjustments, which are usually steep tear faults in basement and thrust crumples in cover. Invariably the structures and movements in the districts have long geologic history and result from intersecting or superimposed deformations of different ages. Salt Lake districts show intersecting Uinta and Cordilleran elements; Colorado dis-tricts show intersecting pre-Cambrian and Tertiary elements, and Bisbee shows Tertiary superimposed on final Paleozoic folding. Thus the position of districts has been determined by the patterns of North American orogenic belts, which make cross-roads in Rocky Mountains and blocks of superimposed deformation in Sierra Nevada, northwest Coast and Canadian Coast Ranges. Essential function of repeated deforma-tion is to strengthen rock, as from shale to slate to schist to gneiss, and thus make it competent to carry channels to depth with or without addition of intrusives. The essence of a mining district is the presence of such competent rocks with long-lived, deep, penetrating breaks reopened to permit passage of heat and associated products from depths to surface. It is suggested that melts such as magmas; metamorphism up to and including granitization; alteration, such as orthoclase-quartz or quartz-sericite or garnet, and also mineralization, may all be by-products of such heat escape along channels made by tectonic forces at specific foci.

Jan 1, 1939

By T. W. Lippert

In these opening remarks, I will endeavor to give a background of continuous casting of metals. Only passing attention will be given to the different processes to be described by the authors whose papers are on the program, as they are far more familiar than I am with their subject matter. Suffice to say that over the past several years the brass, copper, aluminum and magnesium industries have shifted practically completely from conventional static molds to continuous casting machines. The Aluminum Company of America alone has more than 60 continuous machines in operation. The product as continuously cast is superior metallurgically, less scrap loss is involved, costs are generally lower, and the equipment requires little floor space. A continuous machine, operating as it does with deadly constancy, is a ravenous consumer of molten metal, and in most plants one or two machines are well able to handle large banks of melting and refining furnaces. In steel, interest in continuous casting is today more serious than ever before in history, and there is every reason to believe that continuous machines may secure a minor place in the ferrous industry, particularly for tool and alloy analyses. In the past, steel has been commercially cast continuously, and today many tons of steel are being turned out in this manner. It has been said that the cradle of every science is surrounded by dead theorists— and certainly there are innumerable examples of this in the metals industries. An excellent illustration, for instance, is the continuous rolling of metal, a tantalizing objective that for decades on end exhausted . the efforts of a long line of famous, infamous and unknown inventors. Finally, in 1922, John B. Tytus, of the American Rolling Mill Co., brought forth what now seems such an obviously simple scheme— a concave roll face, each stand of progressivcly less concavity. And out of this one change in design sprang today's wide continuous mill rolling steel sheet Ioo in. wide at 2000 ft. per minute. Another excellent example is the con- . tinuous casting of liquid metal into an intermediate form, preferably one requiring little subsequent breakdown. First, the casting of liquid metal alone was fascinating enough. Then someone passed the cast metal directly into a rolling mill, and shortly thereafter this continuously rolled strip was passed directly into a stamping machine. This leitmotiv of a continuous flow of metal from the liquid phase to a consumer end product, fast and inexpensive, and all housed within a small space, was enough to drive some 200 or so inventors into frenzy over the past hundred years. All the ideas, however, like mayflies, had only their brief afternoon of existence. They were born and they died on paper, as constant exemplification of that great void that always exists between mental production and commercial production.

Jan 1, 1945

By Vernon Taylor

CANADA'S oil production is obtained almost entirely from the Turner Valley gas and oil field, in the Province of Alberta. This field, about 30 miles southwest of the city of Calgary and approximately 115 miles north of the United States border, supplied 92 per cent of production in Canada during 1937. In 1938 considerable development took place in this field and total production for the year amounted to 6,688,716 bbl., an increase of 3,922,146 bbl. over the production in 1937, which increased the percentage of production to approximately 97 per cent of Canada's total. In the British Empire, Canada's production is thus comparable to that of Bahrein Island and Burma, each of which produced approxi-mately 7,800,000 bbl. in 1937, being second to Trinidad's production of 15,500,000 bbl. The total production of the British Empire in that year amounted to 2.07 per cent of the world's total. HISTORY Development of the Turner Valley field commenced in 1913, when a well was started near a gas seepage on the banks of the South Fork of Sheep River in the central part of the Valley. This well found small quantities of a light crude oil in beds of Upper Cretaceous age and pre-cipitated a wild boom in 1913-1914 which ended with the beginning of the Great War in 1914. A small amount of drilling was done in the years from 1914 to 1922 and a few wells found small crude-oil production in the upper sands. In 1922 a few wells were started, including the Royalite Oil Company's No. 4 well (R, Fig. 1), which became the discovery well of naphtha pro-duction from the Paleozoic limestone. In October 1924, this well was completed at a depth of 3740 ft., being approximately 300 ft, in the lime-stone, with an initial flow of 600 bbl. of 72° A.P.I. gravity naphtha and 20,000 M cu. ft. of gas per day. Intense activity was not started until the latter part of 1928, when the Okalta No. 1 well (Q, Fig. 1) was drilled, with an initial production of 500 bbl. of naphtha per day. This well was only 1 ¼ miles from Royalite No. 4, but it was approximately 1300 ft.

Jan 1, 1939

By Walter Kauzman

ALL viscous or plastic flow of incompressible matter is the result of shear strain; the changing shape of any body that is being plastically deformed can be completely described in terms of the shear strain occurring at each point in the body.[t] Furthermore, the relative amounts of shear strain occurring in different parts of a body under stress depend upon the relative rates of shear strain at those different points, so that if the dependence of the shear rate of any material on the temperature, shear stress, previous history, etc., were understood, the principles of plastic deformation would be known, and we could calculate how a body made of a given material, having a given shape, and subject to a specified system of forces, would change its shape with time. It may be said, then, that the problem of plasticity resolves itself into, first, the problem of the rates of pure shear processes, and second, the application of what is known about pure shear to actual cases. It is the purpose of this work to investigate the former problem -i.e., the dependence of shear rates on temperature, stress, etc.-from the standpoint of recent developments in the field of chemical-rate theory and with particular reference to the phenomena occurring in the creep of metals and in the plastic flow of crystalline solids in general. It is left for the mechanical engineer, and perhaps the expert in hydrodynamics, to deal with the problem of applications.1 RESOLUTION OF MACROSCOPIC SHEAR INTO MICROSCOPIC MOVEMENTS; RESEMBLANCE TO CHEMICAL REACTIONS Just as any large body is made up of many small units, or atoms, so macroscopically observable shear is the result of many microscopic unit shear processes; just as the understanding of the behavior of large bodies demands the understanding of the atoms of which it is made, so the understanding of macroscopic shear demands the understanding of these fundamental unit processes. The study of shear from this "atomistic" point of view has made considerable progress. There has been fairly complete understanding of shear processes in gases for a long time, at least for nonturbulent flow, as a chapter on gaseous viscosity in any text on the kinetic theory of gases will prove. In recent years Andrade2 and Eyring3 have presented important theories for the flow of liquids and amorphous solids. Becker,4 Orowan,5 Taylor,6 Burgers,7 and Kanter8 have considered the

Jan 1, 1941

By Rudolph Emmel

The mines operated by the South American Development Co. are located in the Zaruma mining district of southwestern Ecuador. They are near the old mining town of Zaruma, which is the only important city in the canton of the same name. The district is situated in the upper end of a valley lying between two spurs of the Cordillera, one of which may be considered the Coast Range and the other an intermediate range. The mining camp proper, known as Portovelo, and the plant are 2.4 km. south of Zaruma, on the north bank of the Amarillo River, a tributary of the Tumbes River, which flows southwestward through Peru to the Pacific. Portovelo is difficult of access; it is reached from Guayaquil by means of river steamers and muleback. 'Embarking at Guayaquil, the route is down the Guayas River, across the Jambeli Canal, and up the Santa Rosa River to Santa Rosa, a distance of 177 km. From Santa Rosa, the road or trail follows the Santa Rosa River, then across the summit of the Coast Range into Portovelo, a distance of 74 km.—a two-day trip on muleback. The mining property of the South American Development Co. comprises 297 lode claims and 142 placer claims. The combined lode claims cover an area, roughly rectangular in shape, 9000 m. long from north to south by 4000 m. wide; the northern edge of the rectangle is about 3000 m. north of the central plaza of Zaruma. Mineral lands in Ecuador are held by virtue of an annual tax per claim paid to the central government, no surface rights being included. HiSTOry The Zaruma mine has been worked by white men since 1549, probably before that it was worked by Indians. The followers of Pizarro, led by traces of gold in the sands of the Tumbes River, followed that stream to its source, worked the gold veins that they found and established the city of Zaruma. Among the mines worked by them were th Sesmo, Leonora, Viscaya, and Mina Grande. Only the soft ores at the outcrop were

Jan 1, 1925

By K. C. Gilbart, Edgar Stansfield

When plants decay in a peat bog the woody parts form a brown pasty mass, or peat muck, largely soluble in alkalis. This brown matter has been termed "ulmin." The same material, but commonly black in color, is found in coal, and there is evidence of the similarity between the material forming the main bulk of the coal and the bulk of the more recently decayed material in peat bogs. The more recent or low-rank coals, such as lignite, little removed from the peat stage, contain notable percentages of alkali-soluble ulmins, but the percentage decreases with increased degree of coalification and is negligible in bituminous or higher rank coals. The determination of the alkali-soluble ulmins in any coal gives, therefore, an indication of its degree of coalification or rank. Coals which contain few or no ulmins soluble in alkalis do contain ulmins which can be rendered soluble by oxidation. The higher the rank of the coal, the more difficult it is to oxidize the insoluble ulmins and make them soluble. High-rank coals can be differentiated by oxidation tests on the insoluble ulmins; but low-rank coals can be characterized by both their soluble and insoluble ulmins. This paper deals with the determination and significance of the alkali-soluble ulmins present as such in the coal. The chemical nature and composition of ulmins are not discussed. Review of Literature The history of the study of ulmin is well given by Stopes and Wheeler.' The action of potash on coal has long been known, as Braconnot in 1819 distinguished between lignites and bituminous coals by stating that the former gave colored solutions with potash. Later the intensity of color was used to give a fuller differentiation. Hoffman2 distinguished between lignites and lignitic coals by the darker color given by the

Jan 1, 1932

By Irving H. Wentworth

The little town of San Nicolás, Tamaulipas, Mexico, lies approximately 60 miles east of Linares, situated in the State of Nuevo Leon, and 150 miles SE. of Monterey, as shown in the sketch-map, Fig. 1. The place is reached from Monterey by the Tampico train as far as Linares, a distance of 92 miles, and then by coach the rest of the way. It is situated in a narrow valley between low hills, the houses forming one main street and a plaza. It is peopled by about 500 inhabitants. The climate is temperate, the thermometer ranging from 90" in summer to a few degrees below freezing-point in winter; but this severe weather only lasts a day or two at a time, when the " northers " blow. There are no streams in the vicinity, but water sufficient for the use of the people is obtained from wells. The rainfall is about the same as that in the rest of NE. Mexico. The rainy months are July, August, and September. The rest of the year is practically dry, with an occasional showery day or two during the winter, when a " norther " is blowing. Timber is abundant in many localities. There are two varieties of oak, besides mesquite, ebony, "maguira," "patol," and a number of other kinds of trees indigenous to this region. I. History. On the discovery of the silver-lead bearing veins occurring in this district, the mining-camp of San Nicolás was founded in 1767 by the Spaniards, and numerous mines were opened and worked for a distance of about 3 miles east and 5 miles west of the town. At the western extremity and near the Car-rolefia mine, a small town called San Pedro was huilt. The

Jan 1, 1913