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By C. M. Loeb, T. E. Norman

The use of ball, rod and tube mills for grinding ore, cement and other materials has grown so rapidly during the past forty years that the world's annual consumption of ferrous grinding media for these mills is now estimated to be between one half million and one million tons per year. Ferrous grinding balls constitute the major portion of this tonnage. Obviously they represent sufficient value to justify thorough studies of the factors governing their performance. The selection of grinding balls is governed principally by: I. Quality (wear resistance, impact resistance, soundness, and the like). 2. Sources of supply and delivered cost. 3. Grinding characteristics or efficiency in the ball mill. This paper deals principally with the quality of ferrous grinding balls. In the study of these factors certain data relative to the fundamental nature of ball wear in ball mills have been obtained. These data are also presented and discussed briefly. The Development of a Suitable Wear Test A study of the fundamental factors governing the quality of grinding balls has been hampered seriously by the fact that a competent test has, in the past, involved the purchase of several hundred tons of balls of a specific type which were then run in one or more ball mills for a period ranging from several months' to several years' duration. Often, during the period of test, it became necessary to change operating conditions or the character of the ore fed to the test mill with the result that the rate of ball consumption changed and the test figures became of little value. Under such circumstances, progress in the development of better grinding balls, has been necessarily slow. Economic factors and variations in the quality of balls produced by different sources of supply generally make it necessary for each mill operator to determine for himself the most suitable type of balls for his mills. In our own ball mill grinding operations at Climax, Colo., we were faced with this problem. After we had run a few large scale wear tests at considerable expense we decided to investigate the possibilities of a small scale wear test which would be capable of testing numerous types of balls within a relatively short time. The most important requirement of any test is, of course, that it give results which can be used to predict accurately the wear in full scale operations. It was known that Ellis and his associates1,2 had developed a method of testing grinding balls by small scale tests run at the Ontario Research Foundation. Ellis' method of testing was used as a starting point in our investigations. In the course of our tests a number of modifications of the original method were found to be desirable so that, by an evolutionary procedure, a method of small scale

Jan 1, 1949

By A. Lee Barrett

The Maintenance Committee of the Coal Division of the American Institute of Mining and Metallurgical Engineers is presenting as a part of this report the second of a series of maintenance cost comparisons. The committee's purpose is to assemble maintenance costs on all equipment connected with mechanical operations at the face of coal mining and to arrange these costs by districts so that comparisons can be made between districts and within districts. The committee, this year, sent 35 questionnaires to representative coal companies who either reported last year or had advised specifically of the inability to report to last year's questionnaire primarily because of limited time. The response to the questionnaire this year as not as good as last year, only 20 of the 35 selected companies returning a completed questionnaire. This year's data have been compiled and combined with last year's data to present a comparison of the 1945 and 1946 costs of loading machines, shortwall cutting machines, universal cutting machines, service locomotives, shuttle cars, and mine cars. The same tabulation by districts is used as was used for 1945. As was indicated by last year's report there is considerable variation in the in cost of mining machinery in the various coal mining districts and due to this high variability it was not felt practical to attempt to arrive at weighted averages. Consequently, all average figures used in this report are straight averages. An analysis was made of companies reporting both this year and last year in an attempt to determine the trend in maintenance costs for different classes of equipment. Ten representative companies are used in this computation. Table I shows the average cost for 1945 and 1946. It is felt that the negative trend in the maintenance cost of universal cutting machines probably represents the effect of the purchase of a relatively large number of new machines in 1946 with little maintenance cost appearing during the first Year of operation. The grand total figure indicates an upward trend amounting to plus 18.7 pet. However, this figure is viewed with some suspicion because of the effect of the universal cutters decreasing maintenance cost and it is concluded that direct application of percentage increase should be made to types of equipment. In Table 2 covering maintenance costs of various types of mining equipment for 1945 and 1946 the results obtained in Table I indicating trends were applied to those

Jan 1, 1949

By G. Sachs, S. I. Liu

Introduction In a previous investigation on the effects of repeated strains of large magnitude on the aluminum alloy 24 ST, it was found that the reduction in ductility by straining in tension was partially restored by a subsequent compression.&apos; As illustrated by the dashed line in Fig I,$ the ductility (e~) retained after prestraining in tension by a certain amount (el) and measured in a subsequent tension test is represented by a straight line sloping down under 4s°. If a compression of the same magnitude as the first tension is inserted (€2 = — €1) between prestraining and final testing in tension, such a "balanced" tension-compression cycle yields a ductility considerably higher than that present after prestraining in tension only. The results of these tests can be correlated with those of an investigation on the effects of prestraining in compression.~ As also shown in Fig I, the ductility in subsequent tensile tests decreased with com- pression, at a rate considerably slower than that after prestraining in tension. The above discussed testing conditions can be considered as special cases of a general straining cycle, consisting of first, straining in tension by an amount el, subsequently straining in compression by an amount e2, and finally determining the retained &apos;ductility, e,, in a tensile test. Prestraining in tension is then represented by el > o and e2 = o. Prestraining in compression is given by e~ = o and e~ < o. Balanced cyclic straining is defined by the condition el > o and cz = — 61. In order to obtain further information on the effects of straining cycles consisting of tension and subsequent compression, further tests were made, varying both the tension strain, el, and the compression strain, e2, within extreme limits; el varied between 0.06 and 0.28 and e2 between — 0.008 and —0.h approximately. Apparently, such tests have not been previously performed. They revealed phenomena which have not been recognized to date, The results of the investigation are herewith reported, without attempting to correlate them with internal processes within the metal structure. However, in order to assist in an analysis of this type, the results have been represented in various manners. In addition, further test data on the effects of prestraining by compression were provided by using specimens of various contours (notched specimens) in the sub-

Jan 1, 1949

By W. N. Lacey, C. G. Yundt, B. H. Sage, J. S. Billheimer

As a part of a general investigation of the separation of bitumen from hydrocarbon mixtures a study was made of a restricted quaternary system composed of methane, decane, tetralin, and bitumen. The work was limited to a pressure of 8000 psi, a temperature of 220 °F, and to a fixed relative proportion of decane, tetralin, and bitumen. The measurements permitted the determination of the distribution of these components in each of the fluid phases. It was not possible to distinguish a second liquid phase in the course of these measurements. Gas-liquid equilibrium "constants" of each of the components were found to vary markedly with the composition of the system while temperature and pressure remained fixed. INTRODUCTION The separation of bitumen frorn naturally occurring hydrocarbon mixtures has been of importance for a number of years in the production of petroleum, especially in the California area. The deposition of this material from crude oils was noted in earlier studies of the solubility of natural gas in crude oil.¹,²,3 Studies of the separation of bitumen from crude oils from the Greeley and Santa Fe Springs fields were carried out."." The behavior of these systems appeared complex and studies of two restricted ternary systems involving mixtures of n-pentane, tetralin, and bitumen,&apos; and of decane, tetralin; and hitumen, confirmed this belief. Reviews of the literature pertaining to the separation of bitumen from naturally occuring and refined hydrocarbons are available." The important effect of methane in the separation of bitu- men from naturally occurring hydrocarbon mixtures was apparent from the earlier studies and for that reason it appeared desirable to investigate a restricted quarternary system involving mixtures of methane. decane, tetralin, and bitumen; data concerning the behavior of mixtures of decane. tetralin. and bitumen having already been obtained.V his study was restricted to a pressure of 8000 psi," a temperatue of 220° F, and fixed relative proportions of bitumen, decane. and tetralin. This composite constituent, hereinafter designated as the less volatile constituent, was made up of 0.0455 weight fraction bitumen. 0.0909 weight fraction decane, and 0.8636 weight fraction tetralin. The experimental method involved bringing together mixtures of methane and the less volatile constituent in varying proportions in a constant volume container at the pressure and temperature indicated above. The composition of each of the phases was determined and from this the extent of the separation of bitumen was established. MATERIALS The bitumen used in this investigation was obtained from the same stocks employed in earlier studies. The crude material from the North Coles Levee field was stored in the laboratory] in a closed drum for a period of five years. Several samples from this stock were subjected to refining operations which were described earlier,&apos; and every effort was made to follow the same procedure in all cases. It was necessary to prepare supplies of bitumen for this investigation at two rather widely different times. These materials have been identified as samples 1 and 2. The composition of the crude bitumen after it was washed with n-pentane at room temperature

Jan 1, 1949

By Laurence A. Dahners

As part of the strategic minerals program, the Bureau of Mines conducted a diamond-drilling project on three barite properties in eastern Tennessee and western North Carolina during the summer and fall of 1944. These properties, the Moccasin Gap prospect and the Krebs property in Cocke County, Tenn., and the Sandy Bottom mine of the Stackhouse group in Madison County, N. C. (fig. 1), are known to have produced some barite. The Bureau of&apos; Mines project was planned to prospect for extensions of the ore bodies. A total of 3,169 feet of diamond drilling was done in 15 holes on the three properties. Tabulations of sample analyses and drill-hole logs are presented in this report. Two other mines of interest in the area are the McCoy and the Williams in Cocke County, Tenn. The Williams adjoins the Krebs. No drilling was done by the bureau in either of these properties.

Jan 1, 1949

26. G. H. S. Price, S. V. Williams, and G. J.O. Garrard: Heavy alloy, its production. properties and uses. Metal Industry (1941) 599 354s 372. 394. 27. R. Kieffer and W. Hotop: p. 320 of ref 12. 28. F. R. Hensel. E. I. Larsen, and E. F. Swazy: Physical properties of metal compositions with a refractory metal base. Chap. 42, 483, Powder Metallurgy, ed. by J. Wulff (1942) Cleveland. 29. R. Kieffer and W. Hotop: p. 290 of ref. 12. 30. H. Freundlich: Kapillarchemie. 211 (1923) Leipzig. 31. W. Ostwald: Zisch. f. Phys. Chemie. (1900) 34, 503. 32. G. A. Hulett: Zisch. f. Phys. Chemie. (1901) 37. 385; and (1904) 47, 357. 33. J C. Chaston: Discussion to Price, Smithells and Williams, p. 257 of ref. 4. 34. W. Dawihl: Untersuchungen ueber die Vorgaenge bei der Abnuetzung von Hartmetallwerkzeugen. Ztsch. f. techn. Phys. (1940) 21 336. 35. W. Dawihl and J. Hinnueber: Ueber den Aufbau der Hartmetallegierungen. Kol-loidzlsch. (1943) 104, 233. 36. F. Skaupy: Dispersoidchemische und verwandte Gesichtspunkte bei Sinter-hartmetallen. Kolloidzlsch. (1942) 98, 92; and (1943) 102, 269. 37. F. C. Kellcy: Cemented tantalum car- bide tools. Trans. ASST (1932) 19, 233. 38. E. W. Engle: Cemented carbides. Chap. 39, 436, Powder Metallurgy, ed. by J. Wulff (1942) Cleveland. 39. W. Dawihl: Zlsch. f. Melallkunde. (1940) 32, 320. 40. P. M. McKenna: Tool Materials (Ce- mented Carbides). Chap. 40. 454. Powder Metallurgy, ed. by J. Wulff (1942) Cleveland. 41. G. A. Meerson. G. L. Sverev, B. Y. Osinovskaja: Zhurnal Prikladnoi Khimii. (1930) 139 66. 42. A. G. Metcalfe: The mutual solid solubility of Tunesten Carbide and Titanium carbide- Metal Trealmenl (1946) 13, 127. 43. P. Schwarzkopf: Powder Metallurgy. 196-201 and 354-356 (1947) New York. 44. H. Burden: The manipulation and sintering of hard-metals. Special Rep. No. 38, p. 78. Iron and Steel Inst.. 1947. London. 45. W. D. Jones: Principles of powder metal- lurgy. 150. (1937) London. 46. J. E. Drapeau: Sintering of powdered copper-tin mixtures. Chap. 32. 332, Powder Metallurgy, ed. by J. Wulff (1942) Cleveland. 47. H. E. Hall: Sintering of copper and tin powder. Metals and Alloys (1939) 10, 297. 48. F. Sauerwald: Present status of powder metallurgy. -.Melallwirlschafl. (1941) 20, 649. 671. 49. H. L. Wain: Powder metallurgy; influence of some processing variables on the properties of sintered bronze. Report ACA-25. Australian Council for Aeronautics (1946) Melbourne. 50. S. L. Hoyt: Constitution of copper-tin alloys. Metals Handhook, 1364. (1939) Cleveland. 51. T. Ishikawa: Studies on the interdiffusion of copper, tin and graphite powders. Nippon Kinzoku Gakkai-Si (1937) I, 226. 52. A. Carter and A. G. Metcalfe. The struc- ture of porous bronze bearings. Special Rep. No. 38, p. 99. Iron and Stecl Inst. (1947) London. 53. R. P. Koehring: Sintering atmospheres for production purposes. Chap. 25, 278. Powder Metallurgy, ed. by J. Wulff (1942) Cleveland. 54. C. G. Goetzel: Some properties of sintcred and hotpressed copper tin compacts. Trans. AIME (1945) 161, 569. 55. J. W. Lennox: The production of some non ferrous engineering components by powder metallurgy. Special Rep. No. 38. p. 174. Iron and Steel Inst., 1947, London. . P. Duwez and H. E. Martens: The power metallurgy of porous metals and alloys having a controlled porosity. TP 2343, Metals Tech. April 1948. This volume. p. 848. 57. E. A. Owen and L. Pickup: X-ray study of the interdiffusion of copper and zinc. Proc. Royal Soc., London, Series A. (1935) 149, 283. 58. C. G. Goetzel: Sintered and hotpressed compacts of copper-zinc powder. Chap. 34. 352, Powder Metallurgy, ed. by J. Wulff (1942) Cleveland. 98, R. Chadwick. E. R. Broadfield, and S. F. Pugh: Observations on the pressing. sintering, and properties of iron-copper powder mixtures. Special Rep. No. 38, p. 151, Iron and Steel Inst. (1947) London. 60. A. Squire: The properties of iron-copper compacts. Watertown Arsenal Lab. Rep. WAL No. 67101. 61. F. C. Kelley: Properties of sintered iron- comer uowder. Iron Age (Aug. 15. 193) 158 57. 62. G. H. Howe: Sinterinn of Alnico. Iron Age (Jan. 11. 1940) 14.5, 27. 63. R. Kieffer and W. Hotop: p. 359 of ref. 12. 64. W. Hotop: Permanent magnets from sintered iron-nickel-aluminum. Stahl und Eisen (1941) 61, 1105. 65. P. R. Kalischer: Some experiments in the production of aluminum-nickel-iron alloys by powder metallurgy. Trans. AIME (1941) 145, 369. 66. S. J. Garvin: Production of sintered per- manent magnets. Special Rep. NO. 38. p. 67. Iron and Steel Inst. 1947, London. 67. F. C. Kelley: Discussion to P. R. Kalischer. p. 375 of ref. 65. 68. R. Kieffer and W. Hotop: p. 357 of ret, 12. 69. C. H. Howe: Sintered alnico. Chapter 48, 530, Powder Metallurgy, ed. by J. Wulff (1942) Cleveland. Powder Metallurgy Seminar (C. G. Goetzel presiding) C. G. Goetzel—The seminar has been opened by a man who has been active in the field for over fourteen years and has made, since then, some major contributions to the advancement of the art. After having been associated with the Moraine Products Division of General Motors Corporation for over ten

Jan 1, 1949

By W. D. Steele, S. D. Brady

The Pittsburgh coal seam in West Virginia contains the largest coal reserves of any coal seam in that State and is, therefore, one of the most important seams, and attains minable thickness and purity throughout that part of the seam extending from the Northern Panhandle to Monon-galia Co. thence south and southwest across the state to Wayne Co. near Hunt-ington. The Pittsburgh coal is also minable in the Upper Potomac region but is now practically exhausted there. The total minable areas of this coal amount to 2,165 sq miles and are estimated, by the West Virginia Geological Survey, to contain 13¼ billion net tons. The largest body of Pittsburgh coal outcrops on the western edge of West Virginia, along the Ohio River as far south as Moundsville, West Va., going under the river at that point and extending at various depths down the river as far as Wetzel Co. line where it thins out to such an extent that it has little practical value, and on the eastern edge this large body outcrops along the Monongahela River. The territory to be covered by this paper is the area known as the Northern West Virginia District comprising Wetzel, Mon-ongalia, Marion, Preston, Harrison, Dodd-ridge, Taylor, Barbour, Upshur, Lewis, Gilmer, Braxton and Calhoun Counties, and is also known as Dist. 3 under the Bituminous Coal Act. This region was originally opened for commercial mining along and adjacent to the Monongahela River around 1852 when the Baltimore and Ohio Railroad was constructed to Fairmont. It has been extensively developed, first, in 1880 (when the Monongahela River Railroad, now B. & 0. R. R., was constructed) between Fairmont and Clarksburg, and later, in 1916, between Morgan-town and Fairmont when the Monongahela Railway was constructed and placed in operation, this area furnishing the major portion of the production over the past years. With the mining out of a great deal of this territory adjacent to the Mononga-hela River considerable interest has been developed in the back acreage; and within the past few years a number of diamond core drill holes have been made in the back areas of Monongalia and Marion Counties. In this back area the oil and gas well drilling showed that the Pittsburgh coal seam was of minable thickness and ranged in depth from 350 to 1,000 ft below the surface of the stream valleys but this drilling did not furnish any definite data as to its thickness and quality. Economic Importance The Pittsburgh seam in Northern West Virginia is of primary importance as a coal resource not only because of its large reserves but because of its contributing a very large part of the coal used in this country for general steam uses. The Pittsburgh seam is a consistently thick seam, averaging 8 ft in thickness, with very easy grades underground, so it has always been

Jan 1, 1949

By Gieskieng, D. H.

Published tables of jaw crusher capacities are compiled for the most part from field performance data, interspersed with interpolations, extrapolations, various safety factors, and other modifications. Such a table attempts to balance and equalize field data from widely different materials, with differences of crushability, efficiency of feeding, sizing of the feed, and so on. The tests described in this paper were undertaken with the objectives of checking previously reported capacities; of studying the effects of various factors upon the capacity, including jaw plate curvature; and, if possible, of deriving a general capacity equation. Such an equation has been derived from the data obtained in these tests. It is given together with factors for its use. While more accuracy than is usually required may be obtained by careful application of the equation, it is of simple form and provides a convenient reference plane upon which the potential capacity of various crushers may be compared, and with which operating adjustments may be made on existing installations. The principal deviation in these tests from the usual approach consists of a laboratory technique which has been developed for the production of selected

Jan 1, 1949

By William H. King

Preliminary examination of the Virgin River manganese deposit was made by C. H. Johnson, Bureau of Mines engineer, in March 1941. During, April and May 8 trenches were dug, a 48-foot inclined shaft was sunk, and 719 linear feet of channel samples were cut. McKelvey and Wiese, of the Federal Geological Survey, completed mapping the deposit, including the entire area of overlying formations comprising the point of land between the outcrop and Lake Mead. The geologic maps, maps, and ore estimates resulting from these examinations formed the basis for a preliminary report by C. H. Johnson, who recommended further exploration by diamond drilling.

Jan 1, 1949

Jan 1, 1949

By Robert Thomson

"The Cobalt camp is by far the most productive camp of the Temiskaming silver-cobalt area. The date of discovery, 1903, is an important one in the history of Canadian mining; from then on prospecting and mining grew rapidly to take the prominent places they now hold in Canadian life.At Cobalt, prospectors and operators, who were to play prominent parts in other Canadian camps, received their initial training. The exploration campaigns leading to the discovery of several new camps were organized at Cobalt, and a considerable part, indeed, of the funds for these campaigns were profits from mining at Cobalt.The discovery of the Cobalt camp was purely accidental, not the result of any purposeful search. Fred LaRose, a blacksmith employed in the construction of the Temiskaming and Northern Ontario Railway, discovered mineral, afterwards determined to be valuable, within a few feet of the right-of-way. This discovery became part of the very productive LaRose mine. The publicity given this discovery, particularly by Willet G. Miller, later Provincial Geologist of Ontario, led to the rapid development of the camp.ProductionCobalt is a great camp by virtue of its silver production; cobalt is also important, although clearly subordinate. Copper, nickel, arsenic, and bismuth are by-products of mining for silver and cobalt and have not been of great importance to date.The following table gives the metal content of ores, concentrates, etc. from the Cobalt camp for the years 1904 to 1954 inclusive, as reported by the mines (l):"

Jan 1, 1949

By J. S. Marsh

Joseph Priestley prepared oxygen on Aug. I, 1774, and noted with great surprise "that a candle burned in this air with a remarkable brilliant flame." On Aug. 2, 1774, some ironmaker possibly began to wonder if this substance could be used to increase his rate of production; at any rate, there is no disputing the fact that the notion of using oxygen for steelmaking in concentrations greater than that available in great abundance—as air—has been in existence for years. Action was delayed by the lack of enough oxygen at a cost within reach of the steelmaker. Within the last several years enough has been available to permit large-scale tests of its use for both combustion, with which this paper is concerned, and for decarburization. The literature is now enormous and easily available; it is sufficient here to cite three items of historic importance in that all are about 25 years old and in that all are remarkably consistent as far as they go, with what is known today.1,2,3 Significance of High-temperature Heat The principal function of the open-hearth furnace is to supply sufficient high-temperature heat to melt the charge and then to increase its temperature to a range suitable for tapping, ordinarily in the neighborhood of 2900°F. That heat is required to make steel is understood by everybody; however, there seems to be some confusion now and then about the significance of high-temperature heat. Transfer of energy—and heat is energy— is always from a point of higher potential to a point of lower potential and, other things being equal, the greater the potential difference, the greater is the rate of transfer of energy. In the open hearth the flame, of course, is the high-potential source. Perhaps the most satisfactory approach is through the notion of theoretical flame temperature, which is the ratio of heat input to the heat content of the combustion products,* the former is composed mainly of heat of combustion of the fuel plus sensible heat of the fuel plus sensible heat of the combustion air. Thus, flame temperature can be increased by increasing the value of the numerator, by decreasing the value of the denominator, or both. The first method is as old as the open-hearth process and, of course, makes use of preheated air; its possibilities have been by no means exhausted. The second method can be put into effect only by changing the composition of the combustion air, since the combustion of a given quantity of fuel produces a definite quantity of product, and since the denominator includes the non-reactive fraction of the air, principally nitrogen. In other words, the denominator consists of the volume of exit gas multiplied by its heat capacity and that volume consists of carbon dioxide and water vapor as reaction

Jan 1, 1949

By Gilles Carrière

"The Huntingdon mine of Quebec Copper Corporation is situated 3 miles south of the village of Eastman, in the Eastern Townships of Quebec. The copper deposit consists of several pyrrhotite-chalcopyrite replacement bodies or bands.The first mining operations on the conspicuous surface gossan of the Huntingdon deposit started in 1865. They were suspended in 1883. The .mine was again active from 1890 to 1893 and from 1912 to 1924. These operations were carried to a depth of 500 feet, and it is estimated that some 150,000 tons of ore were extracted, of a grade reported as varying between 3 Yi and 7 per cent copper.In 1950 a program of exploration was initiated in the area of the old mine, and resulted in the finding of 500,000 tons of ore with a grade of 2 per cent copper. A new shaft was sunk to a depth of 1,160 feet, and by February 1954 the mine was extracting 800 tons of ore daily.General Geology and StructureThe mineralized zones are on the west side of a band of altered volcanic rock, locally called andesite, adjacent to a sill-like body of serpentinized peridotite which lies west of the andesite. The bands of andesite and serpentine extend several miles north and south of the mine. Their strike is generally north 15 degrees east, and they dip steeply east. Their widths vary very considerably along the strike, but in the mine area each is about 450 feet wide on surface. They are enclosed in sediments of the Caldwell series, consisting of greywackes, quartzites, slates, and shales. The andesite belongs to the same series, which is thought to be of Cambrian age (1). The ultrabasic intrusive is post-Ordovician.At p\aces along the serpentine contact the andesite shows a pronounced schistosity; it is parallel to the contact and rarely extends farther than a hundred feet from it. No evidence of strong folding or faulting has been found so far in the mine workings. Some apparent distortions and irregularities in the strike of the contact may all be due to the intrusive nature of the serpentine. In the mine area, transgressive tongues of serpentine point southward in the andesite.A few vertical lamprophyre dykes, not more than five feet thick, cut the other formations at right angles."

Jan 1, 1949

By James G. Crawford

Correlation Of water with its reservoir zone or formation has been one of the applications of oil-field water analysis of greatest direct value to the petroleum engineer. The water in each producing zone tends to have diagnostic characteristics by which it can be distinguished from every other water above or below that zone in that immediate vicinity. Representative analyses of oil-field waters from producing oil and gas fields in the Rocky Mountain region are included, and the diagnostic characteristics are discussed briefly. It is concluded that the generally dilute nature of Rocky Mountain oilfield waters is a result of dilution by meteoric waters, and that there is no relationship between presence or absence of commercial oil and the character of water in a structure. Introduction The study of waters associated With oil and gas began more than 50 years ago and has been well recognized by operators, engineers, and geologists for about 30 years. It appears unnecessary at this time to recite the history of oil-field water analysis; suffice to say that it has proved its worth many times to the production engineer suddenly confronted with water problems in producing oil and gas wells. Chemists and geologists have studied the possible origin of these waters and as Yet the subject is unsolved in many important phases. There are both local and regional problems connected with the explanation of concentrations and character- istics peculiar to each field, each subsurface zone and each province. Criteria useful in postulating the Occurrence of oil Or gas in One province completely fail when applied to another, and data carefully prepared and analyzed from one field may be actually misleading when applied to another. Correlation of water with its reservoir zone or formation has been one of the applications of oil-field water analysis of greatest direct value to the engineer. The concentrations and characteristics of the waters are essential to the engineers and geologists making interpretations of electric logs in this region. The behavior of water under conditions of reservoir temperature and pressure is dependent to a great degree upon its concentration and characteristics, and thus important to the reservoir engineer. With the advent of secondary recovery methods in the Rocky Mountain region the characteristics and treatment of water will become increasingly important. Premises upon which Correlation Is Based A brief review of the geochemical history of oil-field waters will suffice to present the premises upon which correlations of the waters are based. Sedimentary rocks which are now stratified were first sediments in seas, lakes and streams. These sediments were filled interstitially with connate water. With burial the sediments were compressed arid consolidated, integrated and indurated into bed rock and much of the connate water was dispelled. Following the formation of bed rock the strata were sub-

Jan 1, 1949

By Reynold Q. Shotts

The small domestic underfeed stoker as now designed is unusually sensitive to the coking and plastic properties of coals, and when the attempt is made to burn the high rank coking and caking coals of the Appalachian fields, serious trouble may occur. Part of the trouble may be caused by the ash content and clinkering characteristics of the particular coal in use, but more often it is the result of an excessive ac-in of coke in the form of &apos;&apos;trees,, or masses in the fuel bed. Often the zone of burning becomes so restricted that the fire goes out, and in extreme cases the fire may be lifted completely out of the fuel bed and away from the air ports. Even if the fire is preserved, excessive coking may cause response to subsequent heat demand to be slow and irregular. Coke trees seem to grow most readily during periods of hold-fire operation, so that in order to preserve the fire in mild weather it is often necessary to set the timer for such a long operating period each hour that much unneeded and unwanted heat is developed, causing discomfort. During demand periods the fire may pick up so slowly that the intense burning which develops just before stoker cut-off causes a serious overshooting of the thermostat. Stoker coal performance tests which have been made in a number of labora- tories1,2,3,4,5 are one method of approach to the problem Of selecting stoker coals- As yet these tests have not been standardized and they are expensive and time-consuming. The value of the results probably increases with the length of the test. Sherman and co-workers at Battelle Memorial Institute believe that even a one-week test is not too reliable a trial2 and it is quite likely that Others will agree. A great advantage of such tests is that characteristics of coals, other than the tendency to form coke masses, may be evaluated from them. The selection of stoker coals would be greatly facilitated if there existed some simp1e measure Of the tendency Of a a to form coke in a fuel bed. Although possessing all Of the disadvantages Of any small-scale laboratory test, the test for the free-swelling index of coal has been found useful for evaluating the probable effects Of swelling properties upon combustion.7 Ostborg, Limbacherand Sherman, have shown that the test can Predict, roughly, the tendency Of coke to accumulate in the fuel bed Of a domestic stoker. They also gave instances of its value in predicting combustion behavior in some large installations. The use of the test for free-swelling index has become well established and has been adopted as a standard by the American Society for Testing Materials.8 When domestic stoker coal investigations began at the State Mine Experiment Station in the summer of 1944, it was decided

Jan 1, 1949

By P. A. Beck

In the course of work on grain growth in high purity aluminum a simple optical method was developed for detecting the presence or absence of preferred orientation in annealed specimens. The specimens were prepared by grinding, polishing and "deep etching." The etching reagent used for high purity aluminum has been described.* The resulting etch pits produced selective

Jan 1, 1949

By Constantine C. Popoff

Several limestone deposits in western Washington were examined by the Bureau of Mines in 1946. This report presents data obtained from the investigation of limestone deposits in the vicinity of Arlington, Snohomish County, Wash. The work consisted of surface surveys and sampling. Samples were taken where complete, or nearly complete, sections of limestone were exposed or where individual beds were exposed at a number of separate .localities. Areas were cleaned by blasting prior to sampling. Channel samples were cut where practical; otherwise chip samples taken. Twenty-one samples were taken. The locations of the samples and the analyses are shown on maps accompanying this report.

Jan 1, 1949

By Irwin Roman

In studying the possibilities of a continuously recording magnetometer for use along the surface of the earth and in an airplane, the Federal Bureau of Mines was led to a study of the theoretical resolving power of magnetic observations, both in the variation of the total magnetic intensity and in each of the two cornponents ordinarily measured. Along with this general study, an attempt was made to determine the relative worth of the total intensity anomaly and the vertical anomaly in geophysical prospecting. Genera1 considerations led to three conclusions: I. In the northern magnetic hemisphere of the earth, the total intensity anomaly is offset to the south of the vertical anomaly, for a positive anomaly (see Appendix, note 1). 2. The resolving power of magnetic observations decreases rapidly with distance from the disturbing body. 3. The horizontal anomaly has little value in prediction of the disturbing body but might be useful in making a choice between bodies suggested by the vertical or total anomaly. Some of the considerations leading to these conclusions were: I. The normal intensity and the anomalous intensity are vectorially additive; hence for a positive anomaly in the northern magnetic hemisphere the total intensity will be a maximum at some point south of the disturbing body and north of the point at which the line to the disturbing body is parallel to the normal earth&apos;s field. The anomaly itself has a maximum value directly above the body. For a positive anomaly of constant magnitude, the total intensity will be a maximum when the anomaly vector is parallel to the normal vector. This is shown schematically in Fig. I (not to scale) for a magnetic distribution not restricted to a relatively thin sheet in the magnetic meridian. The normal field has a magnitude 10 with vertical component V0 and horizontal component Ho. Six station points along a traverse across the body from south to north are shown at M to S. At each of these stations the normal magnetic field vector terminates at F. At each of these stations the magnetic field vector due to the disturbing body B terminates at A. The line through the station point and the point A passes through B. The magnitude of the anomaly, indicated by the length of the vector terminating at A, is proportional to some power of the distance from the station point to the disturbing body. If the disturbing body B is a concentrated point of magnetic material, the anomaly is proportional to the inverse second power of the distance. For a uniform magnetic distribution over a line perpendicular to the observed traverse, the anomaly is proportional to the inverse first power of the distance. For surface distributions, the law of intensity is more complicated. At each field point, the total magnetic intensity T is the vector sum of the

Jan 1, 1949

By Howard A. Meyerhoff

In western Argentina, in the Province of Mendoza and the Territory of Neuquen, there is a series of solid bitumen deposits which are claimed to be the most extensive in the world. In a linear belt 500 km (311 miles) long, roughly paralleling the axis of the Andes but occupying a variety of positions with respect to the orogenic structures, more than 100 outcrops have been reported. Approximately 70 of these have been prospected, and some mining has been planned or attempted for about half this number. Limited tonnage, high sulphur content, inaccessibility, labor shortages, and disastrous fires have taken a heavy toll among these operations, and in 1947, only 4 deposits were being actively mined, but 8 more were being explored and developed with a view to placing them in production. Inasmuch as these deposits are currently yielding a substantial fraction of Argentina&apos;s limited domestic supply of solid fuels, a brief account of the deposits and of the small industry based upon them will provide a commentary on Argentina&apos;s fuel problem. Character of Solid Bitumens The solid bitumens of Mendoza and Neuquen are petroleum derivatives, as is indicated by the following ultimate analysis : Constituents Per Cent Hydrogen.................... 6.8 Carbon...................... 82.4 Nitrogen..................... 1.6 Oxygen...................... 2.7 Sulphur...................... 2.2 Ash.......................... 4.3 100. 0 In physical appearance they bear a close resemblance to coal and are commonly called carbon. Their specific gravity has an extreme range of 1.10 to 1.777 in 36 samples weighed, but the average is between 1.14 and 1.24. The material is black, lustrous to dull, with blocky to sub-con-choidal fracture. Though brittle, the purest material is softer than anthracite and exhibits slightly more cohesion. This bituminous material is generally known as asfaltita or asphaltite, but definitive chemical studies indicate that the term asphaltite or grahamite can be applied correctly only to the exceptionally pure material of the Auca Mahuida district in Neuquen. Some other name should be used for the chemically variable bitumens found in all other districts, and the designation "asphaltitic pyrobitumen" has been proposed by Carlos A. S. Piscione.1 At the present time these bitumens are finding favor as solid fuel and as a gas-producing medium. They yield heat values of 8650 to 9750 cal,2 or 14,500 to 16,750 Btu per pound, and in consequence of their excellent heating qualities and the scarcity of imported coal, they are marketed as far away as Buenos Aires at a price of go to 95 pesos, or approximately $22 to 23, per metric ton. In burning, the material swells and decomposes into solid, fluid, and gaseous fractions which burn violently though nonexplosively. Its combustibility has been responsible for disasters and virtually complete destruction at Mina La Es-peranza and Mina Santa Marta, and for minor mishaps elsewhere, as at Mina Escondida in August 1947.

Jan 1, 1949

Jan 1, 1949