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By Chester Washburne

AT present it is impossible to estimate closely the amount of oil obtainable from a given area of land. However, after the completion of a few properly distributed prospect wells, one can calculate the approximate yield of the sands penetrated, with a probable error of say 50 per cent. Even rough predictions of this kind are of value in, large operations. Without wells upon it, one can never be absolutely certain that an area will produce any oil whatever, and one can only indulge in wild guesses of the probable productive area, before the geological structure has been carefully contoured and the top of the basal water plotted on a map. This requires wells. At times it is desirable to form an idea of the possible yield of oil in advance of drilling, as in cases where the price asked for undeveloped land seems too high, but where the probability of finding oil is furnished by neighboring development, supported by the geology. In such cases the most one can do is to make an estimate of possible maximum yield, which may of course far exceed results, and which is of use mainly in the prevention of excessive initial investment. The method is very significant in a general way, as in regions like the Bighorn Basin, Wyoming, where the productive sands in the Cretaceous shale are so few and so thin and fine that they cannot develop very great production, although the high quality of the oil probably will counterbalance this defect sufficiently to give local profit in favorable areas. Reservoir Capacity of Sands.-The porosity of a stratum is the measure of its maximum reservoir capacity for liquids and gases. The porosity may be determined experimentally and must be used in connection with the total volume of the sand.

Jan 2, 1915

By H. T. Van Ellis

(Butte Meeting, August, 1913.) THE following is a brief description of the cost accounts in effect at the. mines of the Anaconda Copper Mining Co. The accompanying chart, Table I., shows the distribution of labor, materials, and redistributable accounts to the various operating and repair accounts. OPERATING. Development. Owing to the fact that every mine has its peculiarities in formation and methods, the question of arriving at what charges should be included under the head of " Development " is one that has occasioned considerable thought and comment, and in the cost sheet of the Anaconda Copper Mining Co. this, account has been sub-divided to show the expenses of breaking ground, tramming, timbering, shaft sinking, up-raising, and cutting stations and skip chutes. It has always been the policy of the company to charge the entire cost of this work to operations monthly, whether the mines are producing or not, also the cost of the opening up of new mines; and only surface construction and additions are charged to capital, excepting original machinery installed for operating pumping plants. Explanations of the charges to the various sub-accounts follow: Breaking Ground-Work performed in driving cross-cuts from the station, or cross-cuts from the drifts, and diamond-drill work, for the purpose of discovering or developing ore bodies. Tramming.-Cost of tramming waste produced by cross-cuts mentioned above. When waste is hoisted to another level to be used for filling, the charge to this account stops at the station, and when hoisted to surface the charge includes tramming from the collar of the shaft to the dump. Timbering.-Cost of timbering the cross-cuts mentioned above includes the cost of handling and framing such timbers, but does not include the wages of station tenders and top carmen.

Jan 6, 1913

By R. G. Ward

The temperature gradient in the subhearth metal or "salamandern of the iron bhst furnace results in the establishment of gradients in the concentrations of silicon, manganese, carbon, and sulfur. The temperature and compositional variations observed in three blast furnaces are analyzed according to irreversible thermodynamics and the systems appear to be close to the steady state condition. Apparent heats of transport, Q, for silicon, manganese, carbon, and sulfur are found to be respectively -17.5, -5, -2.1, and+22k cal per g mol. In conclusion the significance of thermal diffusion in extraction metallurgy is briefly discussed. INCREASING interest has been shown in recent years in the application of irreversible thermodynamics to metallurgical problems. In particular studies have been made of the transport of matter in thermal gradients1-' and under chemical gradients imposed by a binary solvent However, no detailed example in extraction metallurgy has been reported although gradients are the essence of many extractive processes. The case of the distribution of elements in molten blast furnace iron under a thermal gradient is discussed here. DATA In blast furnace operation the hearth bottom is often extensively destroyed by molten metal, and the metal may penetrate perhaps 10 ft into the furnace foundations forming a "bear" or "salamander". Several hundred tons of molten metal may thus exist beneath the level of the conventional tap hole and remain relatively undisturbed for several years under a thermal gradient. This system is subject to little convective stirring because the temperature decreases from top to bottom, and mechanical stirring due to movements in the stack and to tapping operations is unlikely to penetrate far into the metal. The system may thus be regarded as static

Jan 1, 1963

By Strathmore R. B. Cooke, Iwao Iwasaki, C. S. Chang

PYRRHOTITE has long been considered a gangue mineral to be eliminated as tailing in the treatment of various sulphide ores. However, in recent years the world-wide lack of sulphur resources has called attention to this mineral as a potential source of both sulphur and iron. Its importance as an economic mineral, however, has not been particularly emphasized. For this reason very little is known about its response to flotation, except that it can be depressed easily in alkaline circuit, by long aeration,1,2 addition of oxidizing agents3 or by starch.4 The object of this work was to study the floatability of pyrrhotite. This includes the effect of oxidation by aeration, of copper activation, and of change in pH.

Jan 2, 1954

By Daniel R. Hull, H. F. Silliman, Earl W. Palmer

The brass-rolling industry has not had a great deal of experience with antimony in its product. There have been some recent excursions with antimony as a corrosion inhibitor in tubes, but in sheet brass it has been regarded with apprehension and generally avoided. This is not to say that contaminations have never occurred, and probably a great many brass mill men have had their own ideas on the effect of such contamination. Our own views were based upon certain experiences some years ago with strip castings that split lengthwise in the early stages of rolling. The nature of this splitting is shown in Fig. I, from a photograph taken in 1922 as a record of 20 bars of 65-35 common brass made with an antimonial brand of copper. These bars were cast 6¾ in. wide by I in. thick by 45 in. long. In the first pass through the rolls, 19 of the 20 split lengthwise throughout their length, while each half curved outward in a wide arc as it emerged from the rolls. In those days, if splitting was not a frequent occurrence, it was not unfamiliar. One can recall periods of short duration when large amounts of common brass would behave in this way. There was nothing imaginary about these spells. The affected metal would split lengthwise in the breakdown rolls, and no maneuvering of mill practice made any difference. The condition would descend like a plague, demoralize the mill for several days, and disappear. It is doubtful if anyone knew the cause—however many explanations may have been current. In 1921 a quantity of split brass was traced to the use of fired small-arms

Jan 1, 1943

By H. F. Silliman, Daniel R. Hull, Earl W. Palmer

The brass-rolling industry has not had a great deal of experience with antimony in its product. There have been some recent excursions with antimony as a corrosion inhibitor in tubes, but in sheet brass it has been regarded with apprehension and generally avoided. This is not to say that contaminations have never occurred, and probably a great many brass mill men have had their own ideas on the effect of such contamination. Our own views were based upon certain experiences some years ago with strip castings that split lengthwise in the early stages of rolling. The nature of this splitting is shown in Fig. I, from a photograph taken in 1922 as a record of 20 bars of 65-35 common brass made with an antimonial brand of copper. These bars were cast 6¾ in. wide by I in. thick by 45 in. long. In the first pass through the rolls, 19 of the 20 split lengthwise throughout their length, while each half curved outward in a wide arc as it emerged from the rolls. In those days, if splitting was not a frequent occurrence, it was not unfamiliar. One can recall periods of short duration when large amounts of common brass would behave in this way. There was nothing imaginary about these spells. The affected metal would split lengthwise in the breakdown rolls, and no maneuvering of mill practice made any difference. The condition would descend like a plague, demoralize the mill for several days, and disappear. It is doubtful if anyone knew the cause—however many explanations may have been current. In 1921 a quantity of split brass was traced to the use of fired small-arms

Jan 1, 1943

By K. B. Nowels

The attainment of efficient flooding to a large extent depends upon a knowledge of fluid movement through porous media and the pressures used in controlling this movement. Little has been understood con-cerning the fundamental principles involved in the forced drive of water-flooding and an attempt will be made to present some data which may be of interest. Considerable data and technical information pertaining to natural and artificial water-flooding have been presented in the past by Torrey, Umpleby, Fettke, Panyity and others. Their papers have thoroughly covered the description of past and present-day methods of oil recovery by flooding in the Bradford field, especially an article by Torreyl in the Petroleum Engineering Handbook. A bibliography of papers devoted to watcr-flooding, published in Mr. Torrey's article, is appended to this paper. No attempt has been made, therefore, to describe the installations and procedure necessary in flooding, thus permitting the writer to deal exclusively with the mechanics of water movement in flooding operations and its relationship to well spacing. Artificial water-flooding will probably always be the most successful in oil fields described by Herold as being under "capillary control"" and will probably be useless in fields naturally under hydraulic or volumetric control. The natural water drive in an oil field under either of these two controls may give efficient recoveries, as a result of the regulated encroachment of edge water. Such a "natural flood" resulting from the influence of edge water must not be confused with the term as used in this paper, however. Any reference to "natural flood" will here refer to the old method of flooding formerly used in the Bradford field. This was discovered largely by accident and utilized the hydrostatic pressure created by a column of water standing in a watered-out oil well in forcing the oil to an adjacent producing well. The same principles are involved in either natural or artificial flooding, and the latter method simply

Jan 1, 1933

By S. Frederick Ravitz

FOUR liquids are ordinarily present in the lead blast furnace during lead smelting. At the bottom is the lead bullion, which is metallic lead containing about one per cent of impurities, including gold, silver, copper, bismuth, arsenic and antimony. Above this is the speiss, which consists essentially of arsenides and antimonides of iron and copper. The speiss is followed by the matte, which consists principally of sulfides of iron, copper and lead1. The top layer is the slag, of which the major constit-uents are silica, lime, alumina, zinc oxide and iron oxide. Similar products are obtained from the dross furnace, which treats the dross obtained in decopperizing lead bullion. The distribution of gold and silver among these various products is of considerable importance in the smelting of lead. In general, the matte and speiss cannot be treated in the lead smelter, and usually are sent to a copper smelter. It is usually desirable, therefore, to keep their gold and silver contents as low as possible, and to collect the precious metals in the bullion. If the bullion, speiss, matte and slag exist together in equilibrium, the gold and silver should distribute themselves among these four liquids in a definite manner, which, other conditions being equal, should depend only on the amounts of gold and silver in the charge to the furnace. It is thus apparent that a knowledge of whether such equi-librium exists is necessary before attempting to study the effects of various compositions of matte and speiss on the distribution of gold and silver among the furnace products2. Moreover, systems consisting of four liquids in equilibrium are very rare, and are of considerable scientific interest.

Jan 1, 1936

Clarence M. Haight, Franklin Furnace, N. J. (communication to the Secretary*).—In that part of Mr. Wilson's paper describing the Gilman cut-and-fill system, a few features do not appear to be fully explained. In what way is the waste used for filling obtained? The text mentions that if waste is encountered when driving the filling raises, these raises are stopped until the fill is needed; that seems to suggest mining the capping for fill, which might make the backs of the stopes bad as the stopes approach the top of the ore. If, on the other hand, the fill is brought to the raises in cars, are the crosscuts that are necessary in ore or waste? Is the cost of this fill included in the stoping costs given? The second, or lower, series of stopes will present a different problem to that which the first series (under the capping) gave. Although no mention is made in the text, it would seem that the second series of stopes will have to be worked on center lines which are offset half the stope width, 20 ft., from the centers of the stopes above, in order to take advantage of the "rafter" effect of the stringers so named. How is the fill to be introduced into the lower stopes? There are no crosscuts mentioned to provide for this; or is it intended to tap the filled stopes above for the fill? In the latter case the method of control of this fill will be of interest. Ore that will admit of a stoping width of 40 ft. with the lengths mentioned in the description is stronger than any with which many mining men are familiar. Has the practice of starting to mine a second stope before the preceding one is filly completed been tried to any extent? If

Jan 1, 1917

By V. W. Bihlman, H. M. Williams

In the construction of internal-combustion engines, the cooling of the combustion chamber and pistons is of great importance. In certain types of engines, the adequate dissipation of heat from the bearings is also important. One of the important factors affecting heat dissipation from these parts is the thermal conductivity of the material used. A search of the technical literature shows that, in general, the thermal conductivity of the elements1 has been determined accurately by a number of investigators. The data on the industrial alloys are, however, meager. For an investigation of these alloys, the thermal-conductivity apparatus described in this paper has been constructed at the laboratory of the General Motors Research Corporation. It is desirable that an apparatus for work of this nature should give fair accuracy of results with a convenient form of specimen and a reasonable rapidity of operation. A summary of the different methods of determining thermal conductivity is given in the first volume of the " Dictionary of Applied Physics," pages 429 and 470. The method selected as best satisfying these conditions is that of Griffith, on page 443, with the addition of a guard ring similar in principle to the method used by Berget (P. 445). Briefly, the method consists of heating one end of a bar T, Fig. 1, electrically, measuring the amount of heat transmitted through the bar by a flow calorimeter J fastened to the other end, and measuring the temperature gradient along the bar. To compensate for the loss of heat laterally, the test bar is surrounded by a guard ring E, in the form of a steel pipe, which is electrically heated at the bottom and cooled at the top with a

Jan 1, 1923

By J. Parke Channing

THE caving system of mining is that method of removing the ore from an underground body in which the top is first attacked and mined out and the capping, or roof, as the case may be, is allowed to fall in or "cave" and fill the space formerly occupied by the mined ore. It is applicable, generally, to large orebodies where the ore is relatively soft. We may say, within moderate limits, that when ore is removed the surrounding ground either caves in or remains open. For example, in mines like the Lake Superior amygda-loid copper mines, when the lode is removed there is left a void which remains open for many years; on the con-trary, mining a Lake Superior soft hematite ore, however carefully it may be done, always produces a caving of the surrounding rocks. We may say, with propriety, therefore, that the caving system is applicable to that type of ore deposit in which the surrounding rock readily caves. Another factor which governs the use of the caving system is the value of the ore itself. Admittedly, any form of caving will not extract 100 per cent. of the ore, and in the case of a very rich orebody it is often desirable to get out every pound of the ore with as little dilution as possible. Under these conditions, some other method of mining, such as that by square sets and filling, is indicated and should be followed. We may say, however, that, looking at it broadly, in the United States the caving system of mining is generally used for the removal of soft hematite and for the so-called "porphyry" coppers. In both cases this method is used where open-pit mining is not possible.

Jan 1, 1922

By V. W. Bihlman, H. M. Williams

In the construction of internal-combustion engines, the cooling of the combustion chamber and pistons is of great importance. In certain types of engines, the adequate dissipation of heat from the bearings is also important. One of the important factors affecting heat dissipation from these parts is the thermal conductivity of the material used. A search of the technical literature shows that, in general, the thermal conductivity of the elements1 has been determined accurately by a number of investigators. The data on the industrial alloys are, however, meager. For an investigation of these alloys, the thermal-conductivity apparatus described in this paper has been constructed at the laboratory of the General Motors Research Corporation. It is desirable that an apparatus for work of this nature should give fair accuracy of results with a convenient form of specimen and a reasonable rapidity of operation. A summary of the different methods of determining thermal conductivity is given in the first volume of the " Dictionary of Applied Physics," pages 429 and 470. The method selected as best satisfying these conditions is that of Griffith, on page 443, with the addition of a guard ring similar in principle to the method used by Berget (P. 445). Briefly, the method consists of heating one end of a bar T, Fig. 1, electrically, measuring the amount of heat transmitted through the bar by a flow calorimeter J fastened to the other end, and measuring the temperature gradient along the bar. To compensate for the loss of heat laterally, the test bar is surrounded by a guard ring E, in the form of a steel pipe, which is electrically heated at the bottom and cooled at the top with a

Jan 1, 1923

Jan 1, 1902

By M. Baeyertr

Since 1915 many papers and books have covered industrial applications of X-rays from various angles. Two of the more recent are a paper by Fink and Archer, which describes in detail the technique of radiography, and a paper by Clark2, which embraces the whole field of X-ray metallogmphy. This paper, therefore, is confined to work of the X-ray Laboratory of the Western Electric Co., which naturally divides into two categories: radiography and diffraction patterns of various types. Radiography Radiography is the field in which the application of X-rays has had most general appeal among the industries which produce or use metals and alloys. Equipment permitting the examination of heavy sections of metals less permeable than aluminum or other light alloys requires apparatus capable of generating hard X-rays over a considerable period of time. The equipment used in the work presented in this paper is practically identical with that described by Fink and Archer in their paper on radiography in industry and is easily capable of penetrating 1/8 in. of lead. Radiography is used in two major groups of problems: (1) in the development of cquipment and tools and (2) in studies of materials. So far there has been no instance in which the use of radiography for routine inspection is justified. This is partly due to the fact that the manufacture of telephone apparatus involves the production of many identical parts by standardized procedures and equipment that has had development and trial before being put on a regular production basis. It is during this stage of development of equipment and tools that radiography has been used to particular advantage.

Jan 1, 1931

By Robert Mehl

THE Widmanstätten figures found in the steels have been long recog-nized and in some aspects carefully studied,1 especially as they occur in cast hypoeutectoid alloys. Aside.from the practical importance of the structures obtained in the steels by various heat treatments, a study of the characteristics of these figures is interesting because of the rich opportunity the system affords, to, obtain new data on the mechanism of segregation from solid solutions. This opportunity is twofold: first, by changing composition within the austenite range the proeutectoid precipitate may be changed from that of ferrite to that of cementite, thus offering the same opportunity for changing the type of precipitate while maintaining the same basic lattice as that afforded by the Cu-Zn alloys;2 and second, the eutectoid inversion leads upon drastic quenching to the formation of martensite, a Widman-stätten figure of unique interest from ;the crystallographic viewpoint, particularly in comparison with those formed on-slow cooling.3 We have, therefore, two types of structure to study: that formed on slow cooling of hypoeutectoid and hypereutectoid alloys, and that formed on quenching hypoeutectoid, eutectoid, and hypereutectoid alloys. For each of these types of structure we require the crystallographic plane in the mother austenite along which the precipitate forms (we shall see that the precipitates in these alloys are invariably platelike in form), and also the orientation of the precipitate upon this plane. Some of these

Jan 1, 1933

Jan 1, 1921

By Raymond Edmundson

BARITE probably was first mined in the United States in 1845, when a small deposit was operated in Prince William County, Virginia1. The next state to produce barite was Missouri, and according to Weigel2, mining began about 1860. Virginia was the leading producer during the early period of barite mining, but by 1893, Missouri was producing almost an equal amount3. From this date, Virginia, although not the leading producer, furnished large quantities of crude barite until oper-ations gradually declined about 1907. Since 1910, there has been only one producer in Virginia. It is not known when barite was discovered in each of the Virginia areas (Fig. 1), but it is reliably reported that mining on a commercial scale began in Campbell-Pittsylvania counties about 1874; Smyth County in 1877; and in the Russell-Tazewell area about 1890. Barite is widely distributed in Virginia, occurring in nineteen counties. The localities that contain material of some economic value have been grouped into six areas (Fig. 1), each designated by the county or counties in which the barite is found. As many of the smaller areas show a similarity in geologic occurrence, they will be considered in this paper as two major groups; namely, Appalachian Valley and Piedmont Province. The first group, which includes the barite deposits of Russell, Tazewell, Smyth, Botetourt and Roanoke counties, lies northwest of the Blue Ridge and its foothills and southeast of the Appalachian plateaus. The other group includes deposits from the Blue Ridge on the west to the western margin of the Coastal Plain, in Campbell, Pittsylvania, Bedford, Grayson, and Fauquier counties.

Jan 1, 1936

By Maurice Cook

NORMALLY the grain size of cold-rolled and annealed copper sheet is of the order of 0.02 to 0.06 mm., and 0.1 min., for example, would, for many purposes, he regarded as undesirably large. The occurrence of very large grain sizes in a few isolated cases of copper sheet led the authors to inquire into the causes giving rise to such unusual results. During the course of this work a very large number of experiments have been carried out to determine the effect of varying the conditions of the final and penultimate rolling and annealing operations, as well as of earlier rolling and annealing treatments. A correspondingly large number of observations have been made, but within the space of one paper it is possible only to outline relatively briefly what appear to be the more important of these experiments and observations. The presentation of the results does not follow chronologically the order in which the experiments were carried out and they have been rearranged for the sake of simplicity. In recent years a considerable amount of work has been done in connection with the recrystallization and grain growth in metals and alloys that take place on annealing, and a number of generalizations have been reached. It is known that the crystal size in wrought material in the annealed condition depends on a number of factors, including the time and temperature of the annealing operations and the nature and amount of cold-work to which the material has been subjected. Results, however, that are not covered by these generalizations can be obtained, which, in some instances, may even appear to he contradictory to them. According to these generalizations gradual changes in grain size are effected by progressive variation of the factors involved in annealing or cold-working. The work recorded in the present paper, however, relates to the development of grain sizes which are far beyond those normally encountered in ordinary annealing operations and far in excess of grain sizes which, according to ordinary standards, would be classified as coarse or large.

Jan 1, 1938

By Graham Bright

METAL mines were developed long before coal mines and the early lighting of underground workings was effected by torches and candles. The early coal mines were outcrop workings and little trouble was experienced from gas, but as the mines became deeper and shaft mines were opened it became apparent that an open-flame lamp was exceed-ingly dangerous where gas occurred. No satisfactory way of lighting gaseous coal mines was found until Sir Humphrey Davy brought out his famous safety lamp in 1815. The introduction of the Davy lamp was a great step forward but it was unsatisfactory from a light standpoint because the gauze absorbed a large percentage of the light given out by the flame. Clanny corrected this by the introduction of a cylindrical glass lens, which not only per-mitted a free distribution of the light from the flame but added greatly to the safety by eliminating the possibility of the flame coming in contact with the gauze and by protecting the flame against air currents. A very complete story of the flame safety lamp since its inception is given in the U. S. Bureau of Mines Bulletin No. 227, by J. W. Paul, L. C. Ilsley and E. J. Gleim, published in 1924. A little more recent publication, known as Safety in Mines Research Board Paper No. 4, entitled "The Light Power of Flame Safety Lamps," by R. V. Wheeler and D. W. Woodhead, was published in England in 1927. The flame safety lamp was the-only lamp available for gaseous mines for about 100 years. Although the incandescent electric lamp has been in use over 50 years, it was not found safe to use this lamp from wired circuits in gaseous locations. The storage battery was advocated shortly after the develop-ment of the incandescent lamp but until the introduction of the tungsten filament in the miniature mine-lamp bulb, the battery lamp was not a real possibility because of the excessive weight of the battery necessary to produce a sufficient amount of light. The actual development of the electric-battery type of lamp took place largely between 1910 and 1915. In England and Europe, the development was almost entirely along the

Jan 1, 1935

By R. W. Raymond

In my former paper (Bans., xii., 410) I quoted the ruling of Judge Hallett, of Colorado, in the "Iron-Smuggler" case, tried before him in June, 1882. Under his charge, the jury in that case found for the defendants, practically declaring that the deposit on the outcrop of which the Iron Silver Mining Company's claim was located was not a " lode," or else that the portion of it within that claim was not the apex. The case was appealed, and the decision of the Supreme Court, given in February, 1886, is reported in 116 U. S. Reports, p. 529. It simply declares that there is nothing in the charge of Judge Hallett to warrant the setting aside the verdict. The definition of a legal lode given in that case, and quoted in my paper at the page above-named, is perhaps the best of several which Judge Hallet has pronounced. That is to say, his earlier definition, that " a lode or vein is a body of mineral, or mineral-bearing rock, within defined boundaries in the general mass of the mountain," is here accompanied with further explanations, which relieve it from the requirement on one hand, that the body shall be continuously ore-bearing if it he only well-defined, and, on the other hand, that the boundaries shall be well-defined if the ore-bearing body be proved to exist. So far as this particular case is concerned, the approval of this ruling by the Supreme Court merely prevents any re-hearing as to the face. Undoubtedly, the evidence was conflicting; and the jury chose to believe, for the purpose of that occasion, the " experts " who

Jan 1, 1887