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By M. B. Standing, D. L. Katz

Equilibrium data are reported on the composition and densities of coexisting vapor and liquid phases as a function of Pressure and temperature for four hydrocarbon systems prepared from crude oil and natural gas. The data were observed over a range of pressures from 1000 to 8220 Ib. per sq. in. and at temperatures ranging from 35' to 250°F. The compositions of the hydrocarbon systems were such that the critical temperatures of the mixtures were lower than the range of the investigation. Under these conditions, it is shown that the composition of the systems has a marked effect upon both the absolute value of the equilibrium constants and the change of the constants with pressure for the several components comprising the system. From weight-balance considerations, it has been possible to construct the partial phase diagram of a mixture of a 49.9" A.P.I. crude oil and natural gas having a gas-oil ratio of 3660 cu. ft. per barrel. Descriptions of the apparatus used, the analytical procedure, the material used, and the equilibrium measurements are included. A knowledge of the physical behavior of naturally occurring hydrocarbon mixtures is fundamental to the treatment of many problems in the production, transportation and rehing of petroleum. The recent discoveries of pools having formation pressures up to 7500 lb. per sq. in. and higher, and the development of full-scale equipment to operate at pressures of 5000 lb. per sq. in. or more have greatly increased the need for knowledge of the composition, temperature, pressure and density relationships of coexisting vapor and liquid hydrocarbon phases. The following paper presents the results of investigations upon 22 mixtures of natural gas and crude oil of known com~o~itio~ that had been brought to equilibrium under controlled conditions of temperature and pressure. Data are presented upon the densities and compositions of the coexisting vapor and liquid phases for four different systems containing hydrocarbon material having boiling points from minus 2 5S°F. to well over I000 F. The data were observed Over a pressure range from Iooo Ib. per Sq. in to 8220 lb. Per sq. in. and a temperature range from 35' to 2 50°F. The accepted method of computing the physical relationship between two coexisting phases of a hydrocarbon mixture is by use of the "equilibrium constant" K as proposed by Souders, Selheimer, and Brown. definition,

Jan 1, 1944

By M. B. Standing, D. L. Katz

Equilibrium data are reported on the composition and densities of coexisting vapor and liquid phases as a function of Pressure and temperature for four hydrocarbon systems prepared from crude oil and natural gas. The data were observed over a range of pressures from 1000 to 8220 Ib. per sq. in. and at temperatures ranging from 35' to 250°F. The compositions of the hydrocarbon systems were such that the critical temperatures of the mixtures were lower than the range of the investigation. Under these conditions, it is shown that the composition of the systems has a marked effect upon both the absolute value of the equilibrium constants and the change of the constants with pressure for the several components comprising the system. From weight-balance considerations, it has been possible to construct the partial phase diagram of a mixture of a 49.9" A.P.I. crude oil and natural gas having a gas-oil ratio of 3660 cu. ft. per barrel. Descriptions of the apparatus used, the analytical procedure, the material used, and the equilibrium measurements are included. A knowledge of the physical behavior of naturally occurring hydrocarbon mixtures is fundamental to the treatment of many problems in the production, transportation and rehing of petroleum. The recent discoveries of pools having formation pressures up to 7500 lb. per sq. in. and higher, and the development of full-scale equipment to operate at pressures of 5000 lb. per sq. in. or more have greatly increased the need for knowledge of the composition, temperature, pressure and density relationships of coexisting vapor and liquid hydrocarbon phases. The following paper presents the results of investigations upon 22 mixtures of natural gas and crude oil of known com~o~itio~ that had been brought to equilibrium under controlled conditions of temperature and pressure. Data are presented upon the densities and compositions of the coexisting vapor and liquid phases for four different systems containing hydrocarbon material having boiling points from minus 2 5S°F. to well over I000 F. The data were observed Over a pressure range from Iooo Ib. per Sq. in to 8220 lb. Per sq. in. and a temperature range from 35' to 2 50°F. The accepted method of computing the physical relationship between two coexisting phases of a hydrocarbon mixture is by use of the "equilibrium constant" K as proposed by Souders, Selheimer, and Brown. definition,

Jan 1, 1944

By R. J. De Angelis, J. B. Cohen, A. Nelson

In this note several recent results on twinning in copper shock-loaded with planar shock waves will be presented and the role of the twins in recrystalliza-tion will be discussed. The twinlike markings first observed in shock-loaded copper by smith1 were identified as twins by De Angelis and Cohen.2 This identification has been confirmed by others.3 In Ref. 2 it was also shown that there is an orientation dependence for twinning at low shock pressures, such that twins in a crystal loaded in [lll] form in the rarefaction or tensile wave but in

Jan 1, 1967

By R. S. Archer

BERYLLIUM has certain properties such as low density, high hardness, good corrosion resistance, low thermal expansion and fairly good electrical conductivity, which would indicate that it, is worthy of consideration as an ingredient of light alloys. It was not until recently, however, that beryllium could be produced with sufficient ease to encourage research along this line. The production of beryllium by electrolysis from a fluoride bath has now developed to the stage where it could be used commercially if there were sufficient demand for the element. Claims made in certain newspapers and technical articles in regard to the strength and corrosion resistance of the aluminum-beryllium alloys are not justified by experimental results. Moreover, beryllium is an expensive metal ($200 a pound at the time this work was done) and, on account of the nature of its ore and the consequent difficulty of its extraction, it will in all probability continue to be a relatively expensive metal, although the cost would undoubtedly be a great deal less than $200 a pound if the metal were produced on a large scale. It seemed, therefore, that low-beryllium alloys offered the greater commercial possibilities except for very special purposes. It was partly for this reason that in the present work emphasis has been placed on beryllium alloys of low beryllium content.

Jan 1, 1928

FRIENDS of the late Charles F. Rand presented in 1930 a sum of money from which the income is available to support various phases of the work of the Institute in which Mr. Rand was so deeply interested. At present the fund amounts to $10,400. The specific terms of the deed of gift are as follows: "The fund collected to establish a memorial to the late Charles F. Rand shall be placed in the custody of the Board of Directors of the American Institute of Mining and Metallurgical Engineers, to be set up as a trust to be known as the `Charles F. Rand Foundation,' the income of which shall each year be applied to a distinct purpose to be decided upon in that year by vote of the Board of Directors. This purpose shall be such as to promote the general welfare of the Institute and to constitute a permanent memorial of the usefulness of Mr. Rand, who for many years gave unstintingly of his time and talents in its service. "It shall be within the discretion of the Board of Directors to establish a medal to be known as the Charles F. Rand Memorial Medal to be awarded at such a time and under such rules as may be determined by the Board of Directors, for Distinguished Achievement in Mining Administration." The establishment of this medal was announced at the annual meeting in February, 1932, the term "mining" being defined in its broad sense to include metallurgy and petroleum. Robert Linton is chairman of the Charles F. Rand Foundation Award Committee.

Jan 1, 1944

By T. Inoue, T. Imaizumi

A simulation model has been developed to find out the possibility of improving the industrial closed-circuit wet grinding operations. The model involves a continuous tumbling mill in combination with a hydrocyclone to recycle the oversize material back to the mill. The mill is described by the breakage, i.e. the selection and the distribution, functions, co-ordinated with the diffusional mixing along the axis. The cyclone classifier is characterized by the partition function with allowance for the non-selective separation of part of the feed material into the underflow. The computer program developed incorporates an interactive capability to modify the operating conditions of the system whenever needed. The results are analysed for the operational conditions characterizing the mill and the classifier. Besides the steady state conditions some observations are also made about the dynamic responses of the closed circuit grinding system.

Jan 1, 1980

FRIENDS of the late Charles F. Rand presented in 1930 a sum of money from which the income is available to support various phases of the work of the Institute in which Mr. Rand was so deeply interested. At present the fund amounts to $10,400. The specific terms of the deed of gift are as follows: "The fund collected to establish a memorial to the late Charles F. Rand shall be placed in the custody of the Board of Directors of the American Institute of Mining and Metallurgical Engineers, to be set up as a trust to be known as the `Charles F. Rand Foundation,' the income of which shall each year be applied to a distinct purpose to be decided upon in that year by vote of the Board of Directors. This purpose shall be such as to promote the general welfare of the Institute and to constitute a permanent memorial of the usefulness of Mr. Rand, who for many years gave unstintingly of his time and talents in its service. "It shall be within the discretion of the Board of Directors to establish a medal to be known as the Charles F. Rand Memorial Medal to be awarded at such a time and under such rules as may be determined by the Board of Directors, for Distinguished Achievement in Mining Administration." The establishment of this medal was announced at the annual meeting in February, 1932, the term "mining" being defined in its broad sense to include metallurgy and petroleum. Robert Linton is chairman of the Charles F. Rand Foundation Award Committee.

Jan 1, 1943

By C. H. G. Bushell, James E. Lawver, William Barbarowicz

Proper use of automatic controls in the process industries is a combination of art and science. Although many phases of automatic control theory can be expressed by precise mathematical relationships, the final control arrangement usually requires considerable effort by trial and error before the optimum control circuit is found. The failure of flotation operators to recognize that control circuits require study and plant experimentation before satisfactory operation occurs has led to a popular misconception that flotation plants simply do not lend themselves to automation. This widespread belief has been overcome to some degree in recent years by the numerous installations of automatic controls that have paid their way by increasing profits in terms of increased recoveries, lowered costs, or higher grade concentrates. WHY CONTROL ? Any form of automation must be justified in terms of ultimate return on in- vestment by improving quality, by increasing plant throughput, or by reducing the total operating costs. Generally speaking, automatic controls rarely re- place a mill operator. They assist the operator in holding important variables within predetermined limits. Large tonnage operations usually can justify a great deal of automation because an increase in one or two units of recovery results in enormous savings compared to the capital and operating costs of controls. DETERMINATION OF CONTROL The first questions in considering plant automation are: 1) What variables must be controlled? 2) What are the optimum levels of the variables? The optimum operating conditions for any process are those which maximize profits. Many of the variables active in flotation processing can be determined by experimentation in the laboratory or pilot plant 10. Although laboratory experiments can pinpoint variables, the true optimum conditions existing at plant level usually must be determined by plant scale experiments. In recent years, the concepts of detailed experimental designs in the laboratory, followed by plant experiments, have reached the stage of maturity where

Jan 1, 1962

FRIENDS of the late Charles F. Rand presented in 1930 a sum of money from which the income is available to support various phases of the work of the Institute in which Mr. Rand was so deeply interested. At present the fund amounts to $10,900. The specific terms of the deed of gift are as follows: "The fund collected to establish a memorial to the late Charles F. Rand shall be placed in the custody of the Board of Directors of the American Institute of Mining and Metallurgical Engineers, to be set up as a trust to be known as the `Charles F. Rand Foundation,' the income of which shall each year be applied to a distinct purpose to be decided upon in that year by vote of the Board of Directors. This purpose shall be such as to promote the general welfare of the Institute and to constitute a permanent memorial of the usefulness of Mr. Rand, who for many years gave unstintingly of his time and talents in its service. "It shall be within the discretion of the Board of Directors to establish a medal to be known as the Charles F. Rand Memorial Medal to be awarded at such a time and under such rules as may be determined by the Board of Directors, for Distinguished Achievement in Mining Administration." The establishment of this medal was announced at the annual meeting in February, 1932, the term "mining" being defined in its broad sense to include metallurgy and petroleum. Robert Linton is chairman of the Charles F. Rand Foundation Award Committee.

Jan 1, 1942

By Alan Morris

In a previous paper1 the results of cutting tests on free-cutting brass rod were reported. Investigation was made of the effects of variation in lead content, microstructure and cold drawing. The author's reply to the discussion of that paper includes a study of the directional cutting properties of drawn and annealed rod. The present paper records the results of tests made on series of samples in which the tin, iron and copper contents have been varied. The apparatus used and method of testing are described in detail in the previous paper. The machine is of the pendulum-operated milling type used and described by Airey and Oxford.2 Angular readings of the height to which the pendulum rises after falling from a fixed position, both when a cut is made and when the pendulum swings freely, give the basis for calculation of the energy consumed in making a cut. Careful weighing of the sample before and after cutting gives a measure of the amount of metal removed. The results are expressed in footpoiinds per cubic inch of metal removed, and have been called "unit cutting energy." In the course of the discussion of the author's earlier paper, W. B. Price reported large-scale tests involving some 50,000 lb. of material. These tests indicated that the addition of as much as 0.6 per cent of iron and 0.25 per cent of tin had apparently no adverse effect on the highspeed cutting characteristics of the rod. The rod also contained a small amount of nickel. The test results reported here tend to confirm his observations. Effect of Variation in Tin Content The castings for this series were made 2 by 1 by 9 in. and were processed as follows: 1. Castings were annealed at 500" C. for 7 hr. 2. Cold-rolled to 0.700 in.

Jan 1, 1933

By R. U. Jackson

Belt conveying is a method of transportation that requires proper servicing and maintenance if completely economical results are to be obtained from the system. With a trucking system, it is common practice to deliver the trucks to a servicing station each day or at the end of each shift. With railroad transportation there is a similar procedure. Sufficient credit is seldom given to this periodic inspection and maintenance procedure, yet it is the key to the successful operation of trucking and rail haulage systems. How about the belt conveyor transportation system? Here is a system that requires no operator for each individual unit. It requires only a main switch and an adequate sequence interlocking system, and the system is so simple to operate that maintenance is considered as only a casual requirement-nothing is done about it until after trouble has developed.

Jan 1, 1956

By Vincent P. Gianella

THE most intense earthquake on the Pacific coast in the last several years, and probably the second most intense shock to occur in Nevada since it was settled, was felt in many Western States shortly after 10 p.m. on Dec. 20, 1932. Be- cause the rifted area contered about the northern end of Cedar Mountain it is referred to as the Cedar Mountain, Nevada, earthquake. An idea of the intensity of the shock may be gathered from the distance at which it was felt: in Wyoming, Utah, Idaho, Nevada, Washing- ton, Oregon, California and Arizona. It is the strongest quake centering in Nevada since the Pleasant Valley earthquake on Oct. 2, 1915. Despite the strength of the vibrations and the large area over which they were felt, relatively little damage was done. The extent of the damage consisted of a few old stone buildings demolished as shown in Fig. 1, much cracked and fallen plaster, many chimneys shaken down and considerable cracking of brick walls. There were no deaths and four people were but slightly injured. The small amount of damage was due, largely, to the scarcity of structures within the area of strong vibrations, but an important factor was the aridity of the region (see Fig. 2) and the shallowness of soil cover so that there was but little water-saturated loose material in which strong secondary vibrations could be formed. Had this earthquake occurred in a region of heavy precipitation and dense population the damage to property and loss of life would undoubtedly have been large, with consequently much more newspaper publicity.

Jan 1, 1933

By Barry H. G. Brady

A state of stable equilibrium is required in a mine structure to ensure that small increases in the mined void are accompanied by only small displacements of the rock mass. Methods of determining the stability of equilibrium in a rock mass currently require a geometrically regular stoping layout, and introduce a number of simplifying assumptions. The method reported in this paper models the mine near-field using Finite Elements, and the far-field using Boundary Elements. The stability of equilibrium in the modelled structure can be assessed directly from the value of selected principal minors of the global stiffness matrix.

Jan 1, 1981

By Victor Rakowsky

A CLEAR understanding of the factors that deter-mine the consumption of zinc metal is essential to a proper survey of the future of the industry and the relation of the several producing districts. With a view of explaining a sound basis for the consider-ation of some of the problems facing the zinc-mining industry of the Oklahoma-Kansas and Missouri district some of these factors are here set out. The zinc industry of the United States furnishes metal for three major uses, viz.: (1) zinking iron and steel (galvanizing); (2) brass making; (3) sheet rolling. Other important uses are for lead desilverization, the manufacture of castings, including die castings, and the manufacture of zinc oxide by the French process, which consists in burning spelter. The use of zinc for galvanizing comprises the coating of sheets, tubes, wire and shaped products, the latter ranging from chains to buckets. The brass-making industry may be sub-divided into manufacture of red brass, yellow brass and white brass, the percentage of zinc in these products being roughly 30, 40 and 80 respectively. The use of white brass is relatively a new thing and it may attain considerable proportions as a substitute for yellow brass. Ingalls estimated the percentage of total metal consumed for the above purposes in pre-war times as follows: HIGH PRODUCTION RECORD, SHORT TONS USES PERCENTAGE OF METAL Galvanizing 60-65 210,000 in 1912 Brass making 17-20 175,000 in 1916 Rolled sheets 10-12 57,000 in 1917 Other uses 5- 7

Jan 3, 1923

By R. W. Raymond

Alexander Brinton Coxe was born in Philadelphia, Pa., Jan. 19, 1838, the second of five sons of Hon. Charles Sidney Coxe and Ann Maria Brinton. A more extended history of his family and its important relations to the development of the United States will be found in my Biographical Notice of his younger brother, Eckley B. Coxe, published in 1895. It is therefore sufficient to say here that Dr. Daniel Coxe, a clis-

Jan 1, 1907

By Walter R. Hibbard

BACKOFEN' reported recently that "the deformation texture of cold-drawn OFHC copper wire, after a reduction in area of 97.3 pct, may still be described as a composite of [lll.] and [loo] directions aligned parallel to the wire axis." In the introduction, he indicated that this was in contrast to the work of Hibbard,' who reported a single [111] texture after a reduction of 96.4 pct. Unfortunately Backofen stated that this was a reduction in area when actually it was a reduction in diameter, as is clearly stated in the reference. Moreover, the results of Backofen are in complete agreement with the results of Hibbard. Backofen's 97.3 pct reduction in area is an 83.3 pct reduction in diameter, after which he foundadouble [ll11 and[l001texture with the former predominating. Similarly, Hibbard; after an 86 pct reduction in diameter found a double [Ill] and [I001 texture with the former predom- inating. Hibbard, however, when he drew the wire further to 96.4 pct reduction in diameter, found primarily a single [Ill1 texture as illustrated by Fig. 2 of ref. 3. Here also, Hibbard- reported evidences of the [loo] recrystallization texture found by Backofen. It might also be pointed out that Backofen not only drew his wire 97.3 pct reduction in area but also etched them over 99 pct reduction in area from 0.125 to 0.01 in. diam. Hibbard's wires were drawn directly to size. In summary, the deformation texture of cold-drawn copper wire still may be described as primarily a single Clll] texture after a sufficient amount of drawing, such as 96.4 pct reduction in diameter." a

Jan 1, 1952

By L. C. De Jong, J. F. Shirley, M. L. Campbell

At the Southern Peru Copper operation in Toque-pala, Peru, a new process flowsheet for the recovery of byproduct molybdenite has proved successful in dealing with complex and highly variable ores. This paper describes the process and the functions of each of the chemicals used. The Toquepala concentrator of the Southern Peru Copper Corp., located approximately 720 miles southeast of Lima near the Chilean border, processes a daily 36,500 tons of ore containing between 0.50 and 3.00% copper. The molybdenite content in the ore also varies greatly ranging from essentially nothing to as high as 0.15%. The 1966 yearly averages were approximately 1.20% copper and 0.03% molybdenite. The Toquepala porphyry deposit is a mushroom-shaped ore body consisting of a flat-lying enriched zone of predominant chalcocite with a stem-like extension of hypogene chalcopyrite ore in depth within and around a large breccia pipe.1 The underlying chalcopyrite ore has not been reached; however, due to the presence of a major post orebody fault, predominantly chalcopyrite ore is present in the north side of the pit. Most of the molybdenite occurs either as small, fine granular, pulverulent masses in vugs or empty voids of breccia, or as thin foliated masses and narrow thread-like filling in rock joints and fractures. The normal occurrence of quartz gangue with the molybdenite gives some basis for correlating the molybdenite mineralization to some later periods of silicification. On April 18, 1962, the molybdenite recovery plant at Toquepala went on stream, approximately 27 months after the copper concentrator had been in production. The plant was designed and built by Southern Peru Copper Corp.'s engineering and mechanical departments. The basic method chosen for separating the molybdenite from the copper concentrate was the sodium hypochlorite-sodium ferrocyan-ide process. The selection of this process was based on the results of an extensive testing program performed by the Colorado School of Mines Research Foundation, Inc. and the economic conditions of the area. The originally designed process could never be fully implemented due to a lack of sodium hypo-chlorite and has had to be continually modified to satisfy the requirements of the kaleidoscope of ores from the mine. The three basic problems that plague the operation of any molybdenite recovery plant are all present at Toquepala in large measure. Both the quantity of plant feed and the quantity of molybdenite contained in the plant feed are continuously changing. Even more detrimental to an efficient operation is the fact that the copper mineralization in the feed frequently changes once in every 24 hours and occasionally once a shift. From the point of view of the molyb-

Jan 1, 1968

By D. B. Hobbs, H. O. Burrows, T. D. Stay

ALUMINUM which has lost its original identity as to source may be considered as secondary. This would include scrap originating in the fabrication of aluminum, which is not consumed at the plant of fabrication, and all material resulting from fabrication, which has lost its original identity regardless of whether it be consumed at the plant of fabrication or not. In general, secondary aluminum may be divided into two classes, commercially pure and alloyed. The chief impurities found in commercially pure aluminum are copper, iron, titanium and silicon; while in aluminum alloys, copper, iron, titanium, silicon, zinc, manganese, magnesium, nickel, or tin, may be present in varying proportions. Occasionally lead and antimony are found in secondary aluminum alloys, especially if the alloy results from remelting vender's automotive scrap. Such alloyed elements as are found in the scrap cannot be removed on remelting. In this, the remelting of secondary aluminum differs from the smelting of secondary copper or most other secondary metals. The majority of secondary materials reach the consumer in the form of remelt ingot or remelt No. 12 ingot. This ingot varies greatly in quality, depending upon the source of the material, and the manner in which it is refined and blended. The principal differences between primary and secondary ingot are: 1. The composition of secondary ingot may be more or less indefinite. 2. Secondary ingot may contain more dross and oxide. Secondary ingot may, however, be used successfully in a great many products. RELATION OF PRIMARY PRODUCTION TO SECONDARY PRODUCTION Table 1, compiled from data published by The American Metal Market, gives an approximate idea of the relation of primary to secondary production. Information obtained from other sources leads the authors to believe that the figures for secondary production are somewhat low.

Jan 1, 1928

By D. B. Hobbs, H. O. Burrows, T. D. Stay

Aluminum which has lost its original identity as to source may be considered as secondary. This would include scrap originating in the fabrication of aluminum, which is not consumed at the plant of fabrication, and all material resulting from fabrication, which has lost its original identity regardless of whether it be consumed at the plant of fabrication or not. In general, secondary aluminum may be divided into two classes, commercially pure and alloyed. The chief impurities found in commercially pure aluminum are copper, iron, titanium and silicon; while in aluminum alloys, copper, iron, titanium, silicon, zinc, manganese, magnesium, nickel, or tin, may be present in varying proportions. Occasionally lead and antimony are found in secondary aluminurn alloys, especially if the alloy results from remelting vender's automotive scrap. Such alloyed elements as are found in the scrap cannot be removed on remelting. In this, the remelting of secondary aluminum differs from the smelting of secondary copper or most other secondary metals. The majority of secondary materials reach the consumer in the form of remelt ingot or remelt No. 12 ingot. This ingot varies greatly in quality, depending upon the source of the material, and the manner in which it is refined and blended. The principal differences between primary and secondary ingot are: 1. The composition of secondary ingot may be more or less inclcfinite. 2. Secondary ingot may contain more dross and oxide. Secondary ingot may, however, be used successfully in a great itiany products. Relation of Primary Production to Secondary Production Table 1, compiled from data published by The Ameriran Metal Market, gives an approxirnatc idea of the relation of primary to srcondary production. Information obtained from other sources leads the authors to believe that the figures for secondary production are somewhat low.

By E. Alan Haley

Accurate and economic control of line and grade on long tunnels, large structures, excavations and waterways has been a problem to surveyors and engineers for decades. The conventional method of surveying, incorporating a level, transit and a number of surveying technicians, has proven to be a very expensive and time-consuming operation. Now, however, engineers have adapted the laser to help ease the problems of surveying, at the same time increasing the efficiency of such operations. The laser, which projects a continuous, narrow red beam of brilliant light, provides a constant alignment reference that does not interfere with personnel or equipment. A complete laser alignment system, specifically designed for and suited to a variety of mining and tunneling operations, has been developed by the Perkin-Elmer Corp. The engineering significance of this development can be fully realized when it is noted that, aside from potentially tremendous economic advantages in terms of labor savings, the laser beam provides a system of alignment that is at least ten times more accurate than presently used optical systems. The new laser system provides accuracies within 10 microinches per foot (1 x 10-5in.) when used with an accessory centering detector. In one of its first field trials, the laser was used for alignment of a two-mile tunnel which showed a total deviation of less than 5/8 in.

Jan 4, 1968