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By P. L. Menaul, P. P. Spafford

This paper discusses the most dangerous form of corrosion encountered in condensate-well oil production, the discovery of the agent causing this corrosion and the remedial chemical treatment proved effective by field use. The injection of ammonium hydroxide, even as little as one quart per day, has proved effective in preventing gas-condensate well corrosion. The injection of "Bone oil" is applied to wells producing brines containing calcium and magnesium salts. Introduction The severe corrosion of equipment in high pressure gas condensate wells has been a problem for several years and numerous papers have been presented on the subject. The term "gas condensate" or "distillate well" is applied to a distinct variety of hydrocarbon producing well, the characteristics of these wells being high bottom-hole (formation) pressures and temperatures and high gas production. These wells usually produce about 40 gal of water per million cubic feet of gas and the gas contains from 0.1 pct to 2 pct carbon dioxide. In the operation of this type of well, the operators soon noted severe internal corrosion of the pipe carrying the production. In some instances the dl tubing has been found to be corroded to perforation in eight months. The high well head pressures of 2500 to 8000 psi makes any weakening of the well equipment by corrosion extremely hazardous. Bursting of the well equipment results in very expensive repair operations and may result in the loss of valuable production, loss of the costly well, or even loss of life. In November 1944, a gas-condensate well in a Gulf Coast field producing from 9500 ft showed a tubing leak. The well was "killed" by filling it with mud through the tubing, and then the tubing was pulled. Corrosion was found to have caused several perforations in the tubing, Fig I. While the mud was being circulated to kill the well, a high pressure jet from the corroded hole in the tubing perforated the casing and damaged the well to the extent that the cost of repairs amounted to $75,000. In November 1944, another gas-con-densate well in a Gulf Coast field producing from 11,400 ft showed tubing failure. This well had been producing an average of 2,500,000 cu ft of gas daily for two years. In the workover of this well, it was found that a hole one inch in diameter had corroded through the tubing and that corrosion had reduced the wall of the tubing to less than half the standard thickness over large areas of the interior of the tubing. It was found that corrosion had also caused two leaks in the casing. After four months spent in an attempted workover failed to make the well safe for further production, the well was plugged and abandoned at a total loss of $300,000,00.

Jan 1, 1948

The Jeffrey operation of Canadian Johns -Manville Co. , Ltd., at Asbestos, Quebec, is considered to be the world's largest asbestos mine. It accounts for approximately 37% of Canadian production of chysotile asbestos and about 13% of world production. Rated capacity is over 600,000 stpy (540,000 mtpy) of fiber, of which well over 90% is exported to the United States and seventy other countries. During the early 1970's the company completed a five-year modernization and expansion program which included the installation of a unique 72 in. by 93 in. gyratory crusher to handle the extremely blocky serpentinized peridotite ore. Because of the large diameter of this crusher the top ring of the shell was made in two halves which were bolted together. Hundred-ton trucks dump from two sides of the crusher into the 200 st (180 mt) dump pocket which is equipped with dust collecting ducts in the walls of the other two sides. The installation was designed to accommodate the eventual use of 200 -ton trucks. Crushed ore at a. size of 7 ½ in. (191 mm) falls into a uniquely designed crushed ore pocket equipped with three sloping steel sides and one vertical side, which make it totally live. Infrared heaters installed in back of the hopper sides prevent the ore from sticking to the steel. Another interesting feature is an eccentric removal bridge which is permanently mounted inside the crushed ore pocket. The two halves of the bridge are let down by electric winches to form a platform on which the eccentric cart travels and from where maintenance is done. Level indications in the crushed ore pocket are by radioactive indicators. Under the crushed ore pocket is a 72 in. by 28 ft (1.83 m by 8.5 m) apron feeder which operates at 7. 2 to 50 fpm (2. 3 to 15. 3 mpm). Crushed ore is discharged to a picking belt for tramp removal. A crossbelt magnetic separator is also mounted over this belt. Permanently mounted belt reels are also situated over the picking belt to facilitate the changing of this unit. A 60 in. (1. 52 m) wide takeaway belt then elevates the crushed ore to t.he surface facilities. Instead of discharging to a crushed ore stockpile, the takeaway conveyor delivers the ore to a 300-ton distribution bin. The ore is then screened and secondary crushed; and the plus ¾ in. (19 m) is "stored in a 3,000 ton bin while the minus ¾ in. is dried and then sent to storage. This system of directly screening primary crushed ore is similar to that used at both the Endako molybdenum and Gibraltar copper operations in British Columbia. While it would seem connecting processing equipment directly to a primary crusher would have an adverse effect on the crusher availability, the 94% of scheduled time this crusher

Jan 1, 1978

By Thomas T. Read

The cost of labor turnover in industry is so large as to justify the adoption of almost any means to bring about its reduction. Intensive study has shown that faulty methods of hiring and discharging men is the most important factor in labor turnover. Complete control over hiring and discharging by the foreman is a relic of outgrown industrial conditions; centralized hiring permits this work to be put on a scientific basis and also does away with many serious evils that cannot, otherwise be reached. Centralized hiring does not impair the authority of the foreman; he hires his men from the employment office and discharges them back to it, instead of from and to the street. The employment manager, being a direct representative of the employer, tends to restore the former relation of direct intercourse between employee and employer that was helpful in avoiding friction between them. Being a specialist,, he is able to bring special knowledge and skill to bear upon the task of selling employment in his concern to desirable workmen; he is also able to give the foreign workman the special attention he requires. Employment managers have been used for the past few years by a number of large organizations, a few of which are engaged in the mining and rnetallurgical industries. They have invariably reduced labor turnover, in some cases to as little as one-tenth of what it had been. So great a reduction is due in part to other changes made in the light of the data made available by scientific study of the labor problem. In my former paper on personnel work' I advocated the more general use of the employment manager in mining and metallurgical enterprises as a means of reducing labor turnover. The form of organization recommended seems not be to understood by all, and I have requested the privilege of explaining it at greater length, since it is perhaps the most important factor of all in personnel work, and has a vital influence on the cost sheet of every industrial enterprise.

Jan 1, 1918

By E. H. Rose

From the more distant members and some not so distant, the plaint is often heard that they cannot justify the expense and time required to attend the AIME Annual Meeting. Almost invariably, the reason given takes this form: "I just don't see that I would get enough out of it." Often the would-be clincher is added: "Besides, the meat of it all comes out in print anyway." Not long ago, a group of us who have seldom missed a meeting in recent years fell to discussing this phenomenon, and found ourselves in emphatic agreement that anyone holding such a belief indicates by his first remark that he does not know how to attend a convention, and by his second, proves it. He is, by and large, the man who has never been there, and of him, there are many.

Jan 1, 1949

By Zay Jeffries

THE history of the development of our great iron and steel industry has been recorded in many publications, not the least important of which are the TRANSACTIONS of the American Institute of Mining and Metallurgical Engineers. During the life of the Institute, of less than 60 years, the annual production of pig iron in the United States has increased more than 23 times. Such a rate of growth may seem small when compared with that of the automotive industry, which has increased 100 times in the last 20 years, or when compared with the growth of other industries of recent birth. The comparison appears less unfavorable, however, when the fact is taken into consideration that the iron and steel industry has existed on the earth in some form for thousands of years. The trade journals, the Department of Commerce and technical societies keep us currently informed concerning technical and corporate developments and the statistics of the American iron and steel industry. Merely to describe the high spots of the industry as it exists today would require a book of no small size. It involves the utilization of about 900,000 people, the payment of $1,400,000,000 in annual wages and salaries, the-investment of $14,000,000,000, the mining annually of 70,000,000 tons of iron ore, 15,000,000 tons of limestone, and 120,000,000 tons of coal. It results in the production of 40,000,000 long tons of pig iron and 50,000,000 long tons of steel ingot. In addition, the industry includes ownership and operation of railroads and steamship lines, the production of cement, timber, coke, gas, by-products, and many other activities. The leading part played by the iron and steel industry in promoting the confidence of the public in corporations and corporate management is well known. The industry has also provided worthy examples of vertical integration and mass production. The social activities within the industry have been no small factor in promoting the fuller development and greater happiness of the American working man-and his family. In this connection I advise reading a paper by Theodore W. Robinson,1 which

Jan 1, 1930

By Arthur F. Taggart

The major portion of the work described in this paper was performed by R. W. Young, † a graduate student in the department of Mining and Metallurgy, Sheffield Scientific School, Yale University, working under a cooperative agreement between the Hardinge Conical Mill Co., the Sheffield Scientific School, and himself. Since this cooperative scheme is at present in effect in the case of a considerable number of other students in the department and since it is the hope of the school that the privilege thus extended may be utilized even more freely in the future by mining and manufacturing companies, it may not be amiss at this point to give a summary of the general plan. Briefly it is as follows: A graduate student, whose undergraduate work in this or other universities shows promise of ability to handle research work, is chosen by conference between the company and instructor involved. The aim of the company in the agreement then entered into is to obtain the solution of one or more of the technical problems with which it may be confronted, or, at the end of 1 or 2 years, to obtain as an employee a man especially trained in its work. As a means to accomplish one or both of these ends, the company furnishes the machine, apparatus, or material to be tested and pays the student during his graduate work a small salary, usually just sufficient to cover his living expenses, tuition and fees. The aim of the student is special training along a line in which he is particularly interested, the attainment of his advanced degree, and the chance to show to his future employer ability to handle such problems as may be presented to him. In return for the financial aid which he receives he agrees to devote at least half of his working time to the special problem submitted by his company. The other half is devoted to study of the collateral subjects required by the department for the granting of the degree which the student seeks. The student further agrees to enter the employ of the company in question at a wage not greater than that paid in like positions to recent graduates not specially trained and to remain with his employer at such wage for at east 1 year. If the student is to obtain a degree, the special work forming the basis of his investigation must be such as will involve real research and not mere routine manipulation. The subject is chosen by conference between the three parties to the agreement. The work is carried on under the direct supervision of the instructor involved. The school furnishes the general laboratory and library equipment essential to the pursuit of any extended investigation. In

Jan 1, 1918

As 1970 develops and industrial minerals stand at a crucial point in their progress, research and development programs appear to be the key needed to open up new uses for each mineral's future growth. Radically new processes are needed for making a host of new synthetic products from mineral raw materials which will more nearly meet the demanding specifications required for high performance in space, nuclear and defense applications. Consumer applications for high temperature environments will be needed and are important for continuing the nations economic mineral position. In addition, an acute materials problem limits the effectiveness of some of the newer concepts for controlling ail pollution. What is needed then, according to a report printed by the National Academy of Sciences, is the carefully planned development of a limited number of major centers at universities to provide for both basic research and training of personnel; the nurturing of interdisciplinary mechanisms for research and problem solving within these centers; the achieving of a better balance between physics and chemistry within research, emphasizing the chemical aspects of the material sciences; and the enhancement of a broader professional identity by unifying the various disciplines involved into a possible federation of existing societies which have an interest in the problems. [EE] presents its 1969 annual industrial minerals review, where individual authors evaluate the status of each industrial mineral and recount the major developments which occurred during the year.

Jan 1, 1970

By Warren B. Davis

Introduction If a subject this broad were to be covered in even moderate detail, it would require a set of books about the size of an encyclopedia. Since an acceptable length for this paper is a small fraction of one book, it will have to consist of a few samples of the subjects that I think are the most pertinent to World Fossil Fuel Economics. I plan to discuss the trends in world energy demand, particularly in the U. S. and Europe; the consumption patterns and cost patterns of oil, gas and coal; the prospects of synthetics; and some of the effects of government regulation of fuel economics. World Energy Demands Fig. 1 shows Free World energy consumption by principal areas for the period from 1950 to 1970 and a forecast for the period from 1970 to 1985. These figures include only the measurable forms of energy. An example of energy consumption that is not measured is the wood a peasant might cut in the forest and bum in a fireplace to heat his home. This omission probably is a very small part of the total. This forecast is not identical with that of Wayne E. Glenn (see Page 22), but the differences in total energy consumption are not significant. The U. S. consumption, which was 55 percent of the world total in 1950, had declined to 45 percent by 1970, and is expected to decline further to 38 percent by 1985. Western Europe has consumed 28 percent of the total from 1950 to 1970 and is expected to lose share slightly between 1970 and 1985. The most spectacular gainer is Japan, which increased consumption from 2.5 percent in 1950 to 7.5 percent in 1970, and is expected to reach nearly 17 percent by 1985. The over-all Free World total has grown from 62 quadrillion Btu (equivalent to 29 million B/D of crude oil) in 1950 to 151 quadrillion by 1970, an average growth rate of 4.5 percent/year. This total is expected to grow at a rate of 5 percent/year between now and 1985, reaching 315 quadrillion Btu (equivalent to nearly 150 million B/D). Fig. 2 shows which fuels supplied this energy between 1950 and 1970, and gives an estimate of how it will be supplied between 1970 and 1985.

Jan 1, 1971

By G. D. Just

INTRODUCTION Large scale underground mining involves the bulk handling of fragmented material. The cost and efficiency of the mining systems is there- fore significantly influenced by material flow characteristics. Flow problems may occur in the form of ore pass blockages which interrupt the free flow at extraction openings. The costs of such delays can be readily assessed and compared to the costs incurred in reducing blockages by improved fragmentation or larger ore passes. In practice the problem is more complex than this statement suggests because it is generally un- economic to design for zero ore blockages. Another major flow problem occurs in the form of relative movement of ore and waste as the fragmented material is extracted. This produces waste dilution in the recovered ore and influences total ore recovery. This flow problem is much more complex than the ore block- age phenomena. Many questions concerning the precise flow characteristics remain unanswered because of the variability of size distributions, particle shapes, material properties and the total extraction layout and design. Model studies can provide a visual and quantitative illustration of probable flow characteristics but full scale data collection is necessary to evaluate the precision of such information. The methods and types of data obtained must be carefully selected to recover the maximum volume of useful information for operational control and future design. It is essential that honest precision levels are assigned to the data and any subsequent analyses. Grade control data may give misleading short term information on flow characteristics because of the difficulty in knowing the true grade of the mass of material before extraction commences. However, in the long term control of extraction grades is vital to the profitable operation of the mining system. The most efficient extraction design and operational schedule can only be determined after all of the facts and variables are known. This is usually only possible after the orebody has been completely extracted. However, if design and operational personnel have a full appreciation of the nature and variability of material flow under different conditions the best possible results should be achieved. The most significant features of material flow are out- lined in this paper in order to provide mine planning and mine management personnel with some of the necessary information relating to material flow. Available facts and reliable figures from selected publications are noted in association with unbiased and hopefully accurate opinions of the relevance of the data to mine design and mine system control. Possible future developments and profitable areas for research into material flow problems are also detailed. MATERIAL FLOW AND MINING METHODS The effects of material flow on the design and operation of an integrated underground ore handling system is one factor which is common to most mining methods. Analysis of the system as detailed by Just, 1980, permits the identification of unit process objectives. For example, a typical underground ore handling system as illustrated in Figure 1, involves the following unit operations:- (i) Gravity flow of ore in stope (ii) Ore extraction at base of stope (iii) Ore haulage on the production level (iv) Dumping of ore into ore pass system (v) Gravity flow of ore in the ore pass (vi) Underground crushing of ore (vii) Haulage of crushed ore to shaft (viii) Hoisting of ore to the surface. Average flow rates in each of these unit operations can be misleading due to variability in incremental capacity caused by flow blockages and machine delays. Thus to effectively analyse the probable performance of the system, it is necessary to have a measure of the flow loading and haulage rate variability. Mechanical equipment performance specifications can be used to provide such information for loading, haulage and crushing; however, in the case of the gravity flow of material field measurements are required to relate the probability of "hang-ups" to the degree of fragmentation. Factors affecting the frequency of flow stoppages are, size, distribution and cohesiveness of broken material and the geometry and size of the flow channel. Ore pass channel design is relatively simple since regular cross-sectional shapes are used

Jan 1, 1981

By I. W. L. Finlay, H. R. Ogden, R. Jaffee, D. J. Maykuth

Aluminum has been found to be soluble in a titanium to about 26 pct, and to raise the temperature range of transformation from a to 8. Two intermediate phoses exist in the system, a new face-centered tetragonal phase, designated as 7, which occurs between 34 and 46 pct Al, and TiAI Metallographic and X-ray diffraction data were used to determine the diagram. ALUMINUM is one of the useful alloying additions for titanium-base alloys. It is an important constituent in two commercial alloys released in 1950, one containing 4 pct A1 and 4 pct Mn, and the other containing 3 pct A1 and 5 pct Cr as the metallic alloy content. It is probable that, in the future, other titanium alloys containing aluminum will be released. In the course of alloy development work, some of the features of the constitution of titanium-rich Ti-A1 alloys have been developed. These are described in the present paper. The only available information on the Ti-A1 system concerns the aluminum-rich end of the diagram. In summarizing the early work, Hansen' indicated that there is little solubility of titanium in aluminum, and that a two-phase region exists up to the intermediate compound, TiA1a (37.2 wt pct Ti), which has a congruent melting point at 1355°C. Fink' has reported that a peritectic reaction occurs at 665°C between the melt and TiA1³ to form the terminal solid solution of titanium in aluminum. The solubility of titanium in aluminum has been established at 0.24 pct at 510°C and is estimated to be between 1 and 1.5 pct at the peritectic temperature. No information has been published on the diagram above TiAl,, other than a statement- hat aluminum raises the a to ß transformation temperature of titanium. Materials and Preparation of Alloys Iodide-type titanium and high-purity aluminum were used in this investigation. Typical analyses of these materials are given in Table 1. Alloys were prepared by arc melting on a water-cooled copper hearth, using the techniques described previously for contamination-free melting.' Weight losses during melting were very low, ranging from 0 to 0.02 g in a 10 to 15 g charge, indicating that little or no loss of aluminum occurred during melting. This permitted the use of nominal compositions for these alloys. Alloy ingots containing from 0 to 7.5 pct A1 were rolled in air at 850°C to 0.040 in. sheet. Alloys containing from 7.5 to 16 pct A1 could only be rolled about 25 pct reduction at temperatures up to and including 1200°C. Alloys containing above 16 pct A1

Jan 1, 1952

By H. A. Wheeler

That lead and zinc deposits are the result of prolonged,, slow deposition is the idea of most students of ore deposits, and in many cases, where the ore-bearing solutions have been very weak or the precipitating conditions have been very feeble, the ore accumulations have undoubtedly taken a long period of time. As these two vital conditions have been subject to great variations in the different mining camps, the following example is highly interesting in showing that deposition can be very rapid under favorable conditions, geologically speaking, and also extremely recent. In fact, the writer is inclined to regard most, if not all, of the Mississippi Valley deposits of lead and zinc as probably being very young, at least not older than Tertiary, if not Quarternary, in age. The extensive Joplin lead and zinc district, in southwestern Missouri, which is about 60 years old and has numerous mines that were abandoned from 1 to 50 years ago, shows that the lead and zinc today are in an active condition of solution and redeposition, although these two metals occur in the predominant form of sulfides. The mine waters from the older and more or less abandoned portions of the district are frequently so acid, mainly from the oxidation of associated pyrite, as to necessitate the use of wooden pipes and pumps. The first boom in the Oklahoma zinc fields, which is the southwestern extension of the Joplin district, occurred when ore was accidentally struck in drilling a water well. Among the mines then opened up was the Mission mine, at Lincolnville, Ottawa County, Okla. This mine was opened in 1903 in lean "sheet ground," or a flat blanket formation of chert carrying disseminated zinc blende, or "jack," and galena. Theore-body was very free from iron pyrites and the concentrates were very high grade, the "mineral," or lead concentrates, assayed 80 to 85 per cent. lead and the jack, or sphalerite, assayed 60 to 65 per cent. zinc. The orebody was very shallow, occurring at a depth of 76 to 95 ft. (22 to 28 m.) and very wet, requiring three or four pumps to handle the water. The mine was operated until 1914, when it was closed by litigation and immediately filled with water. The second Oklahoma boom, five years ago, opened up the large, active camps of Picher, Tar River, and Century, which are located 2 to 5 mi. west of Lincolnville. They are considerably deeper, being farther down on the westwardly dipping monocline that emanates from the Ozark

Jan 1, 1920

By T. T. Chen, P. Pint

Based on the mineralogy, phase characteristics and compositions of the smelter feed, the smelter products and the smelter wastes, the sources and distributions of mercury and arsenic in the Afton copper smelter, Kamloops, British Columbia have been determined. Of the total mercury In the feed, approximately 33% is in solid solution in tennantite, 51% is in native copper and 16% occurs as mercurian silver. Arsenic in the feed occurs mainly as tennantite. Under current smelting conditions, 99.6% of the total mercury In the feeds enters the off-gas cleaning system. From this off-gas, about 1% of the total mercury, occurring as dust, is recirculated to the flotation concentrate; 4.6% of the total mercury is contained in SO2 scrubber sludge which is discharged to tailings. Approximately 78% of the total arsenic in the smelter reports in the copper products; 20% is incorporated in the dust and slag which are subsequently recirculated to the mill. Only 1.8% is rejected as scrubber sludge, and less than 0.2% 1s released to the mercury scrubber.

Jan 1, 1984

By G. W. Jones

THIS paper describes experiments in which eight test samples of gelatin dynamite were fired in three different types of apparatus and the quantity and composition of the gaseous products of detonation determined. The special dynamites were so prepared that the oxygen balance of the samples varied from -35.0 to +6.0 g. per 100 g. of explosive, including the wrapper. By means of this graded series of explosives, the relation between oxygen balance and gaseous products of detonation could be studied explicitly. The effect of varying oxygen balance on explosive strength has been discussed in another paper.1 The apparatus employed in the work described in the present paper included (1) the Bichel gage, a steel bomb of 15-1. volume; (2) the Crawshaw-Jones confined detonation apparatus, a steel cannon from which the explosive is fired into a pipe of 90-1. volume; and (3) the Hercules tank, an apparatus in which the explosive is confined in a quartz block which is placed in a steel tank of about 4500-1. volume. A full description of the apparatus is given later. VARIABLES AFFECTING COMPOSITION OF DETONATION PRODUCTS The character of the detonation products of commercial explosives is governed in part by the same factors that affect the combustion products from explosive mixtures of air with gases or vapors. In either case, combustible materials-namely, carbon, hydrogen, and sometimes sulfur-are present and combined variously. In an exploding gas mixture the combustibles are oxidized by oxygen in the admixed air, whereas with explosives the necessary oxygen is provided by oxygen-carrying materials in the explosive ingredients.

Jan 1, 1928

By B. H. Sage, R. T. Carter, W. N. Lacey

The phase behavior of a number of binary systems consisting of parafin hydro-carbons has been determined in recent years. In addition, the composition of the coexisting phases of mixtures of crude oil and natural gas has been investigated.~ However, the latter study did not include information concerning the influence of the concentration of a component upon its distribution between two coexisting phases. Owing to the paucity of such information it was considered desirable to investigate in some detail the composition of the coexisting phases in the methane-propane-n-pentane system throughout the greater part of the two-phase region at a tempera-ture of 100°F. Information of this nature also permits the establishment of the critical behavior of this ternary system. Method The compositions of the coexisting phases in this ternary system at 100°F. were deter-mined by withdrawing samples from a pres-sure vessel containing a heterogeneous mixture of the three components that had been brought 10 equilibrium by mechanical agitation at the desired pressure and tem-perature. The samples were withdrawn under such conditions that the equilibrium was not disturbed and the composition of each of the phases was ascertained by means of the conventional low-temperature fractionation procedure. The apparatus employed in this investi-gation was nearly the same as that utilized in an earlier study of the methane-pentane system.~ Several minor modifica-tions in the arrangement of the apparatus were made in the interest of simplifying the procedure and avoiding the possibility of condensation in the tubing connecting the equilibrium apparatus with the analyti-cal equipment. The pressures were meas-ured by means of a pressure balance with a precision of 0.5 lb. per sq. in. It is believed that the equilibrium pressure was ascer-tained with an uncertainty of not more than 2 lb. per sq. in., even though small varia-tions in pressure obtained during the withdrawal of the samples. The tempera-ture of the equilibrium equipment was maintained by use of an automatically controlled oil bath. The bath temperature was determined by means of a copper-constantan thermocouple, the electromo-tive force being determined by means of a potentiometric circuit of such a nature as to reduce the uncertainty of the tempera ture to less than O.I f. The fractionating column employed in the determination of the composition of the gas phase had a diameter of 0.12 in. and was approximately 4 ft. long, while the column employed in the analysis of the liquid phase was 0.18 in. in diameter and about 5 ft. long. Each column was equipped with the conventional constant-volume receivers, which were maintained at a constant temperature by means of an automatically controlled oil bath. In nearly every case the distillation in thr neighborhood of the transition between

Jan 1, 1941

By W. N. Lacey, R. T. Carter, B. H. Sage

The phase behavior of a number of binary systems consisting of parafin hydro-carbons has been determined in recent years. In addition, the composition of the coexisting phases of mixtures of crude oil and natural gas has been investigated.~ However, the latter study did not include information concerning the influence of the concentration of a component upon its distribution between two coexisting phases. Owing to the paucity of such information it was considered desirable to investigate in some detail the composition of the coexisting phases in the methane-propane-n-pentane system throughout the greater part of the two-phase region at a tempera-ture of 100°F. Information of this nature also permits the establishment of the critical behavior of this ternary system. Method The compositions of the coexisting phases in this ternary system at 100°F. were deter-mined by withdrawing samples from a pres-sure vessel containing a heterogeneous mixture of the three components that had been brought 10 equilibrium by mechanical agitation at the desired pressure and tem-perature. The samples were withdrawn under such conditions that the equilibrium was not disturbed and the composition of each of the phases was ascertained by means of the conventional low-temperature fractionation procedure. The apparatus employed in this investi-gation was nearly the same as that utilized in an earlier study of the methane-pentane system.~ Several minor modifica-tions in the arrangement of the apparatus were made in the interest of simplifying the procedure and avoiding the possibility of condensation in the tubing connecting the equilibrium apparatus with the analyti-cal equipment. The pressures were meas-ured by means of a pressure balance with a precision of 0.5 lb. per sq. in. It is believed that the equilibrium pressure was ascer-tained with an uncertainty of not more than 2 lb. per sq. in., even though small varia-tions in pressure obtained during the withdrawal of the samples. The tempera-ture of the equilibrium equipment was maintained by use of an automatically controlled oil bath. The bath temperature was determined by means of a copper-constantan thermocouple, the electromo-tive force being determined by means of a potentiometric circuit of such a nature as to reduce the uncertainty of the tempera ture to less than O.I f. The fractionating column employed in the determination of the composition of the gas phase had a diameter of 0.12 in. and was approximately 4 ft. long, while the column employed in the analysis of the liquid phase was 0.18 in. in diameter and about 5 ft. long. Each column was equipped with the conventional constant-volume receivers, which were maintained at a constant temperature by means of an automatically controlled oil bath. In nearly every case the distillation in thr neighborhood of the transition between

Jan 1, 1941

By John V. Beall

There is an underlying surge to mining in the Philippines." So said A. R. "Ham" Reed, general manager Itogon-Suyoc Mines, Inc., to this reporter last November. Itogon-Suyoc is a small company with a struggling gold mine, a mixed sulfide mine and some prospects. In the Republic of Philippines (ROP), politics, which have an effect on mining, create some uncertainties. By July 1974, no mining company may have more than 40% foreign ownership. The ownership provision is a matter of concern to such important companies as Atlas and Benguet Consolidated and is generally considered a deterrent to new foreign investment. Under these circumstances, Reed's comments are of interest. On foreign prospectors: Don't come in cold; find a Philippine partner or buy into a company already here. Physical conditions of exploration are tough-terrain, communications -but the mineral potential is excellent.

Jan 4, 1969

By F. M. Simonds, E. Z. Burns

The Rawley property is located in the Kerber Creek mining-district, Saguache county, Colorado, at an elevation of 10,600 ft. (See sketch-map, Fig. 1.) Ore was found in this vicinity as early as 1880, and claims covering a large area were located and in many instances patented. The ores, however, being of comparatively low grade, and the nearest railway station, Villa Grove, being some 20 miles away, it is extremely doubtful whether any considerable amount of ore was ever handled at a profit. It is safe to say that several hundred thousand dollars were spent (a large part in building mills) previous to 1902-03. About that time a very capable promoter gathered together a group of these claims and interested some New York people, who had had no previous mining experience, in the purchase of these claims. Following the organization of a company, this promoter became General Manager. As often happens under such conditions, the first step was to erect a mill to treat 100 tons per day. It may not be fair to this enterprise to say that the failure which followed might have been foretold, simply on general principles, but this much is certain—the water supply fluctuates in the course of a season through a wide range and for a considerable portion of the year was inadequate to run this mill at capacity. Further, it is currently reported that some of the mill foundations were placed on ice. However true this statement may be, it is a fact that, when first inspected by us, many of the belts in the mill were held on'their pulleys by means of idlers. A shut-down followed, with a material re-adjustment of interests, at which time we became consulting engineers for the company.

Jan 1, 1914

By William B. Senseman

FoR reasons well known to mining engineers, wet grinding is quite universal in plants having to do with the extraction of metallic values from crude ores. In the processing of the nonmetallic and industrial minerals, dry grinding is the more common method. The crude materials usually contain less moisture than is required for wet grinding and the products usually are marketed in dry form; most of them as powders. To grind wet, therefore, would entail the addition of water and an expense for drying the product, which is not justified. Furthermore, the material would be a dried cake that would still have to be pulverized or disintegrated before use. For producing fine products, air separators have largely replaced the earlier practice of sizing with screens and bolting reels. Mills in which the air-separating feature is an integral part of the design are now commonplace. Mill designs are many and air systems have developed along various lines, but for the purpose of this discussion, only the fundamental idea need be emphasized— the idea of using air for sizing and removing pulverized material from a grinding mill. About 20 years ago, when the use of mills equipped with air separation had become common practice, heated air or gas was introduced to such a system for the removal of moisture. The purpose of this discussion is to outline the developments and trends that have followed this experiment. It is an important development, for mills equipped with air separation are now universally used for pulverizing not only nonmetallic and industrial minerals, but a great variety of other materials. All such mills are essentially the same. Dried material is pulverized, removed by an air stream, trapped in a cyclone collector, and relatively clean air from the cyclone is returned through a fan to the mill. There is no theoretical need for a vent from the system. The practical need is to vent the air that leaks into the system; and, since the cyclone is not 100 per cent efficient as a dust collector, this vented air carries some dust with it. The initial attempt at drying was made on a system like that described, by the addition of a furnace. The minus pressure within the mill draws hot gas from the furnace. Infiltration air, along with the drying gases and evaporated moisture, is vented as before. The first application was made to a mill used for pulverizing coal. The coal contained very little moisture, so very little drying effect was needed for the success of this experiment. Actually, some calculated efficiencies of over 100 per cent were obtained before due allowance was made for the conversion of mill power into useful heat. When moisture is low, the heat obtained from the conversion of milt power is an appreciable part of that required. That drying can be effected in the short time interval available in a grinding mill of this type is better understood by visual-

Jan 1, 1948

By D. V. Carter, Dan C. Williams, John R. Coombs

Exploration was active in East and East Central Texas during 1944. Ten oil fields were discovered during the year, of which four show promise of development. The discovery wells of the Sand Flat and Tyler, South fields were drilled to a depth greater than 10,000 ft., and the latter field now produces from the Pettit at a depth of 9890 ft. The Sand Flat well was plugged back to the Paluxy. The other two fields are Glen Rose producers near 8000 ft. The Pickton field produces from the Bacon Lime and Winnsboro from the Rodessa section. The Eylau field, Bowie County, was significant as the first Smackover production in Texas. Magnolia drilled a test in the Concord field, which topped salt. The most extensive and significant development in the district was the Carthage gas-condensate field. It expanded from the 8000 acres of last year to an estimated 190,000 acres, or about 300 sq. miles, and is not defined as yet. The first oil production in the Carthage area was made from the Travis Peak in 1944 in the Rogers Lacy's Cameron Lumber Company well No. I, on the northwestern side of the field. The New Hope field, Franklin County, scored the largest number of completions during 1944 with 24, bringing its total number of wells to 27. Two more pays were opened and produced as dual completions with the older horizons. The Manziel field, Wood County, had 19 new wells added during the year, for a total of 29, while the Pittsburgh field, Camp County, reached a total of 23 wells by completing 14 new ones. Material shortages and drilling restrictions dropped the total number of producing wells completed in the district from 171 during 1943 to 141 for 1944. Abandonments increased from 531 during 1943 to 609 for 1944. Of this number, 479 were in the East Texas field. Subsidy payments had very little effect in the district and it was mostly a few of the old fault-line fields that had any wells to fall within the requirements for subsidy payments. The prices of crude oil remained constant in the district except for increases as a result of subsidy payments. Production and Probation Wartime demands called for increased allowables for many fields, consequently the condensate and oil production for 1944 increased to 190,016,180, which is up 6.9 per cent over 1943. The East Texas field, of course, remained the principal producer of the district, accounting for 134,768'499 bbl. during the year, or 71 per cent of the district total production of condensate and oil. The field topped its own 1943 production by 4.8 per cent and became the first field in the world to produce 2 billion barrels of oil. The Hawkins field remained the second largest oil producer in the district, with 13,317,088 bbl. for the year, a drop of 6.8 per cent from 1943, while Van field was third with 11,635,708 bbl. The

Jan 1, 1945

By William B. Senseman

FoR reasons well known to mining engineers, wet grinding is quite universal in plants having to do with the extraction of metallic values from crude ores. In the processing of the nonmetallic and industrial minerals, dry grinding is the more common method. The crude materials usually contain less moisture than is required for wet grinding and the products usually are marketed in dry form; most of them as powders. To grind wet, therefore, would entail the addition of water and an expense for drying the product, which is not justified. Furthermore, the material would be a dried cake that would still have to be pulverized or disintegrated before use. For producing fine products, air separators have largely replaced the earlier practice of sizing with screens and bolting reels. Mills in which the air-separating feature is an integral part of the design are now commonplace. Mill designs are many and air systems have developed along various lines, but for the purpose of this discussion, only the fundamental idea need be emphasized— the idea of using air for sizing and removing pulverized material from a grinding mill. About 20 years ago, when the use of mills equipped with air separation had become common practice, heated air or gas was introduced to such a system for the removal of moisture. The purpose of this discussion is to outline the developments and trends that have followed this experiment. It is an important development, for mills equipped with air separation are now universally used for pulverizing not only nonmetallic and industrial minerals, but a great variety of other materials. All such mills are essentially the same. Dried material is pulverized, removed by an air stream, trapped in a cyclone collector, and relatively clean air from the cyclone is returned through a fan to the mill. There is no theoretical need for a vent from the system. The practical need is to vent the air that leaks into the system; and, since the cyclone is not 100 per cent efficient as a dust collector, this vented air carries some dust with it. The initial attempt at drying was made on a system like that described, by the addition of a furnace. The minus pressure within the mill draws hot gas from the furnace. Infiltration air, along with the drying gases and evaporated moisture, is vented as before. The first application was made to a mill used for pulverizing coal. The coal contained very little moisture, so very little drying effect was needed for the success of this experiment. Actually, some calculated efficiencies of over 100 per cent were obtained before due allowance was made for the conversion of mill power into useful heat. When moisture is low, the heat obtained from the conversion of milt power is an appreciable part of that required. That drying can be effected in the short time interval available in a grinding mill of this type is better understood by visual-

Jan 1, 1948