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By E. V. d’Invilliers

The position of these magnetic ore-mines, with reference to the county-seat, is shown in Fig. 1. They are situated on the south margin of the Great Valley, five miles south of Lebanon, and about midway between Reading on the Schuylkill River and Harrisburg on the Susquehanna River, in three prominent, contiguous hills, standing in front of the Mesozoic red shale arid sandstone hill country of northern Lancaster and southern Lebanon counties, and overlooking the great limestone plain to the north. The three hills, named respectively Big, Middle, and Grassy Hills, and separated from each other by two branches of Furnace Creek, range in a nearly east and west direction for a distance of about one mile. Their summits are respectively 870, 715, and 700 feet above tide. The railroad line opposite the base of Middle Hill is 575 feet above tide at Cornwall and 471 feet at Lebauon. These features are all distinctly illustrated in the contour-line map accompanying this paper, but are made still more clear in the relief. map, Fig. 2, comprising, as it does, about six square miles of territory contiguous to the ore-mines. This is a photographic plate of a model made by Mr. A. E. Lehman, from surveys of my own and Mr. W. F. Shunk. The model was built in layers of cardboard, each layer representing one 10-foot contour-carve line. The scale was the same as the original map, 400 feet= 1 inch, without any vertical exaggeration. The lowest contour-line is 530 feet above ocean level; the highest, 1075 feet. The center of the model was made the focusing-point of the view, which was taken—according to scale—51/2 miles north from and 24 miles above the focusing-point, looking southward. When first mined in the last century these hills exhibited smoothlyrounded surfaces, composed of soft weathered ore of great parity, beneath which lay the great mass of hard ore, constituting the whole

Jan 1, 1886

By W. A. Klikoff, I. Fatt

The concept of fractional wet wattability is examined. Fractional water wettability of a reservoir rock is defined as the fraction of the internal surface urea that is in contact with water. Capillary pressure and relalive permeability of unconsolidated sand are shown to be functions of fractional wettability. INTRODUCTION The petroleum industry has long recognized that wettability of reservoir rock has an important effect on multiphase flow of oil, water and gas through reservoirs. As early as 1928 the American Petroleum Institute sponsored a study of wettability as part of API Project 27 at the U. of Michigan.' Despite 30 years of research, there is still little exact knowledge of the wettability of reservoir rocks. There are two parts to the wettability problem. After agreeing to a uniform nomenclature in regard to wettability,' the first question to be answered is, "What is the in situ wettability of a given reservoir rock?" If this can he answered the next question is, "What part does wettability play in determining the characteristics of multiphase fluid flow through the rock?" This paper represents an oblique attack on the problem of wettability. No attempt is made here to answer the basic question of wettability in situ. instead the consequences of the concept of fractional wettability are examined. Multiphase flow in sandpacks is shown to he highly influenced by fractional wettability. Jennings' has given 3 definition of wettability and the other terms used in discussing wettability. These terms must be applied to the physical situation existing In reservoir rock. A survey of the pertinent literature from 1928 to 1956 indicates that the concept of a contact angle was applied to reservoir rock in the same way it would be applied to a flat, homogeneous surface. Attempts were made to state quantitatively the wettability of a reservoir rock in terms of a contact angle which was presumably constant at all points on the very rough and heterogeneous interior surface of a porous rock. Calhoun, et al,3-6 prepared synthetic consolidated and un-consolidated porous media in which they claimed there was a known uniform contact angle. They then showed the effects on the capillary pressure and relative permeability characteristics of varying this angle. The API Project 47 at the U. of Texas' and others' have made extensive studies of an indirect approach to the contact angle through the use of heat of wetting data. Even if successful. however, this approach also states the wettability of porous rock in terms of a contact angle which is uniform over the entirc surface. If the angle varies from one part to another on the internal surface, there is no way of determining from the measurements the area distribution of contact angles. In 1956 Brown and Fatt5 suggested that the concept of a contact angle, as applied to reservoir rock, be abandoned. This suggestion was made because it is known that the internal surface of most reservoir rocks is composed of many different minerals, cach with a different surface chemistry and a different capacity to adsorh surface active materials from reservoir fluids. Furthermore, the operation of a contact angle in determining the form of a fluid-fluid interface is difficult to picture in the very complex geometry of a pore. Brown and Fatt proposed that the wettability of reservoir rock be stated in terms of the fractional internal surface area that is in contact with water or oil. All surfaces on which there is water are called water-wet; surfaces on which there is oil are called oil-wet. The fractional water wettability is then stated as a number which represents the fraction of the internal surface that is in contact with water. A symmetrical statement can be made for the fractional oil wettability. The concept of a fractional wettability as previously stated has in its favor the recognition of the heterogeneous mineral composition of most reservoir rocks. Another point in its favor is that fractional wettability can be measured quantitatively with relative ease. Hol-brook and Bernard10 se a simple dye adsorption test to obtain fractional wettability of reservoir rocks. Amott11 uses a combination of imbibition and displacement to arrive at a wettability index of reservoir rocks which seems related to fractional wettability in the range 0.25 to 0.75 fractional water wettability. Jennings" has shown the changes in relative permeability that take place when a porous material is changed from unity to zero fractional water wettability. He also shows that reservoir rocks in their natural state, but at room temperature and atmospheric pressure, have relative permeability characteristics which would indi-

By Lucius W. Mayer

The iron-mines of the Ilsede Hutte Co. are at a town called Peine, about 20 miles east of the city of Hanover, on the railroad to Brunswick (Braunschweig). Hanover, the capital of the province, is a military city, of approximately 250,000 inhabitants, and Brunswick, 33 miles to the westward, has half this number. The mines here described are located in a hamlet called Bulten. The Ilsede Hutte Co. operates two mines, 1.5 miles apart, in this district, Gruber Bulten Adenstadt and Gruber Lengede Bodenstadt. It also operates an iron-mine north of Hanover, known as Eiserhaven, and one in the Harz mountains, the Georg Friedrich, at Grauhof. At Bulten a coarse conglomerate, a, Figs. 1 and 2, contains nodules of limonite, cemented together by calcium phosphate. The ore contains Fe, 25 to 45; Mn, 3 to 4; P, 0.6 to 1.4; '5, 0.02 to 0.09; and CaCO,, 40 per cent. Directly above the conglomerate is limestone, 6, followed by a mixture of clay and sand, c. Below the conglomerate is a hard clay floor, d. The ore-body, from 10 to 12 km. long, and from 3 to 4 km. wide, has a maximum thickness of 20 m. It dips approximately 10" S.E., and strikes K 45° E. Diamond-drill prospecting shows that the thickness diminishes to 1 m. as the end of the deposit is approached to the northward. At this point the deposit is 250 m. below the surface. In Fig. 2, the arrow, A, indicates the general direction of the work along the face, a, which is carried forward in a straight line for its entire length. At B, a train is approaching, which has come from the bench-track, shown at C, by a circuitous route, and is dumping the overburden behind the face, in the space left by the excavated rock. Formerly the work at this mine mas essentially open-cut, the deposit having a very strong outcrop. Figs. 1 and 2 show also

Jan 1, 1909

By Welton J. Crook

Unless present, in considerable praportion, metals of the precious-metal group—other than gold and silver—are not readily detected by the methods of fire assaying usually applied to ores and metallurgical products. Platinum, when present in small quantity, will ordinarily be reported as silver unless special methods of parting are used. Other elements occurring in the gold itself are all fluxed and slagged in the assay operation and if analyses are made on bullions the melting and slagging operations to which the bullion has been subjected may eliminate most of the associated elements. On the other hand, the analysis of precipitate from the cyanide treatment of gold ores may reveal the presence of many unexpected elements, such as tungsten and molybdenum. It is uncertain, however, whether many of the elements present in the precipitate are derived from the ore gangue or from the gold itself. No very general survey of the distribution of metallic elements in gold seems to have been made. Rose and Newman,l in connection with the composition of native gold, say in part as follows: Gold is occasionally found alloyed with copper and sometimes also with iron, bismuth, lead, mercury, tin, antimony, palladium or rhodium. Rhodium gold from Mexico was found to be of the specific gravity 15.5 to 16.8 and contained 34 to 43 per cent of rhodium. The native alloy of palladium, gold, and silver from Porpez contains 85.98 per cent of gold, 9.85 per cent palladium and 4.17 per cent silver. Mal-donitk, from Victoria, contains gold 64.5 per cent, bismuth 35.5 per cent (Louis). Dana2 says that native gold is usually alloyed with silver in varying amounts, and that sometimes it also contains traces of copper and iron. Rare varieties contain palladium, rhodium and bismuth. Other authors, for instance Zeigler3 and Clark,4 give similar information. Most references on the subject agree that ordinary native golds contain, in common, the elements silver, copper and iron. After completion of the work of which this paper is a record, the conclusion is reached that all ordinary native gold probably does contain these elements and, although in certain cases other elements may be found to be present, that it is difficult to

Jan 1, 1943

By Welton J. Crook

Unless present, in considerable praportion, metals of the precious-metal group—other than gold and silver—are not readily detected by the methods of fire assaying usually applied to ores and metallurgical products. Platinum, when present in small quantity, will ordinarily be reported as silver unless special methods of parting are used. Other elements occurring in the gold itself are all fluxed and slagged in the assay operation and if analyses are made on bullions the melting and slagging operations to which the bullion has been subjected may eliminate most of the associated elements. On the other hand, the analysis of precipitate from the cyanide treatment of gold ores may reveal the presence of many unexpected elements, such as tungsten and molybdenum. It is uncertain, however, whether many of the elements present in the precipitate are derived from the ore gangue or from the gold itself. No very general survey of the distribution of metallic elements in gold seems to have been made. Rose and Newman,l in connection with the composition of native gold, say in part as follows: Gold is occasionally found alloyed with copper and sometimes also with iron, bismuth, lead, mercury, tin, antimony, palladium or rhodium. Rhodium gold from Mexico was found to be of the specific gravity 15.5 to 16.8 and contained 34 to 43 per cent of rhodium. The native alloy of palladium, gold, and silver from Porpez contains 85.98 per cent of gold, 9.85 per cent palladium and 4.17 per cent silver. Mal-donitk, from Victoria, contains gold 64.5 per cent, bismuth 35.5 per cent (Louis). Dana2 says that native gold is usually alloyed with silver in varying amounts, and that sometimes it also contains traces of copper and iron. Rare varieties contain palladium, rhodium and bismuth. Other authors, for instance Zeigler3 and Clark,4 give similar information. Most references on the subject agree that ordinary native golds contain, in common, the elements silver, copper and iron. After completion of the work of which this paper is a record, the conclusion is reached that all ordinary native gold probably does contain these elements and, although in certain cases other elements may be found to be present, that it is difficult to

Jan 1, 1943

By M. C. Young

The Ozark Lead Company operating facilities are located in Reynolds County at the south end of the "New Lead Belt" of southeast Missouri. Development of this wholly owned subsidiary of Kennecott Copper Corporation started in May 1964, with a six foot diameter by 1250 foot deep steel lined shaft. A 20-foot diameter, 1480 foot deep, concrete lined production shaft was collared in March 1968. Production from the facilities began that month and has reached a present average of approximately 6000 tons per day. This paper describes the fully automatic system used to hoist the lead-zinc ore from a depth of 1420 feet to the surface crushing and concentrating facilities, as well as the man and materials hoisting system which allows the lowering of large equipment into the mine. MINING Galena, sphalerite and some copper minerals are found in several mineralized zones of the relatively flat lying dolomite of the "Bonneterre formation". The mineable ore zones vary from 10 feet to 110 feet thick, from 200 feet to 1200 feet wide, and several thousands of feet on strike. Two-boom diesel-hydraulic jumbos equipped with rotary percussion drills are used for both development and production. The jumbos are used principally to open the room and pillar stopes, and a track mounted down hole drill is used to bench in areas where the ore thickness warrants. Explosives used are ANFO, dynamite, and water-jell which are detonated by electric blasting caps. Broken ore (and waste) is hauled by rubber tired transports to chuted transfer raises. Approximately every 500 feet, these raises connect the orebody to the 15 foot by 28 foot train haulage level below. Two twenty ton diesel-hydraulic locomotives haul 160 tons per trip to storage pockets which have a total storage of 1500 tons of material. From these pockets the material is fed over a 6 foot by 20 foot mechanical vibrating feeder which includes one 4 foot by 6 foot grizzly section to a 48 inch by 60 inch jaw crusher. The grizzly and crusher products are transferred horizontally 45 feet on a 48 inch conveyor belt, to one of two 750 ton storage pockets. The material can flow unimpeded into one pocket or be deflected into the second pocket by a movable rock filled hopper. LOADING POCKET The material in each storage pocket is controlled by six lengths of ship anchor chain. The upper end of the 20 foot chain is anchored behind a brow in the pocket, while the lower ends are joined by a header. The lower ends of the chains are raised by two electric powered marine barge winches using 3/4 inch cables. The crusher operator controls the raising and lowering of these chains from a console in the crusher station. The upper and lower travel of the chains is controlled by cams and limit switches on the winch drive. The winches are located within 5 feet of the shaft, and shaft water continually causes problems with the electric components. A malfunction in the upper travel switch will cause the winch to pull the chains into the cable sheave (breaking the cable or sheave), while the lower switch causes the winch to unwind too much rope. Serious consideration is being given to changing the electric motors to pneumatic, since pneumatic motors will eliminate the need of any electrics at the winches. The winches can be "bottomed out" against the sheave without damage to the cable or sheave when raising the chains, and can be allowed to "free wheel" to lower the chains. A surge pocket below the two storage pockets feeds material to two

Jan 1, 1975

By C. S. Barrett, D. B. Masson

Martensitic transformations have been found in AgCd both upon cold-working at room temperature and cooling to lower temperatures. The crystal structures of the transformation products were found to be close-packed hexagonal in the first case and or-thorhombic in the latter. The transformation characteristics also were studied. Similar treatment of AuZn alloys failed to yield any transformation. THE literature on martensitic transformations of body-centered cubic metals and alloys indicates widespread instability of this structure at low temperatures, a tendency which merits further study. The body-centered cubic ß-phase of CuZn, for example, when it contained less than 42 wt pct Zn, was found by Greninger and Mooradian' and others' to transform on cooling to subzero temperatures to a phase that was tentatively considered to be tetragonal. Further work by Massalski and Barrett" demonstrated that cold work at low temperatures causes a partial transformation of ß CuZn of higher Zn content. The structures of the strain-induced transformation products were found to be different from those induced by simple cooling. Another well-known martensitic transformation among body-centered cubic phases is that of ß AuCd, first studied with X-rays by Olander,' then very thoroughly by Chang and Read.5,6 Here again transformation was found to occur both as a result of cooling and of strain. The alkali metals Li and Na, as well as certain Li-Mg alloys, also undergo transformation from their normal body-centered cubic structure, both on cooling and on cold-working. The phase AgCd, the subject of the present report, should be expected to behave quite similarly to CuZn for a number of reasons. It is the chemical analogue of CuZn, silver being directly below copper and cadmium directly below zinc in the periodic table. The size factors (percent difference in size) of the atoms, possibly a consideration in the stability of the ß-phases, are +3.1 in AgCd and + 4.2 in CuZn. Likewise the relative electronegativities of the two pairs of metals are about the same, CuZn possessing an electronegativity difference of 1.0 and AgCd one of 0.8. These values are from a table of electronegativities given by Darken and Gurry." The phase diagrams of the two systems around 50 atomic percent are similar, both possessing a disordered body-centered cubic phase, ß, at high temperatures and an ordered bcc phase, ß, at room temperature; however, the ß and ß' phases of AgCd are separated by a hexagonal phase, [, stable in the range 220-440oC, which has no analogue in CuZn. There has been confusion in the literature as to the structures of the ß' and [-phases. The phase diagram in the ASM handbook'" has the structures of the two phases interchanged; however, Hansen" reports the correct relative positions and Muldawer" verified that ß', the low-temperature phase, is body-centered cubic. Work by the present authors also

Jan 1, 1959

By D. H. Newland

New York has a small but not insignificant place in the oil and natural gas industries of the United States. It has had a continuous record as an oil producer since 1872, with an aggregate yield of about 104,000,000 bbl. The reported output for 1935 was 4,237,000 bbl., a gain of more than 10 per cent for the year and a total that has been exceeded only in the early period of flush production half a century ago. The industry has been steadily building up since 1920 with the successful practice of the water drive, which has given a new lease of life to pools that had been practically drained of oil recoverable by pumping. An additional output of 2000 bbl. or more per acre is being procured by this method. Altogether the fields in New York State cover about 55,000 acres. Their limits are well defined and it is unlikely that they will be extended in the future, although there is some prospect of finding additional supplies by deeper drilling. The oil from New York is all classed as Pennsylvania grade, for which the recent price has been about $2.50 a barrel. It is refined at Olean, Wellsville and Bolivar, in the oil district, and partly in Pennsylvania refineries. Exploration for natural gas, outside of the established districts, was considerable during the year. Altogether 59 wells were drilled, distributed over 13 counties, of which 33 were listed as producers and 26 were dry. At the close of the year, 13 wells were in process of drilling. The 33 producing wells had a combined estimated flow of 278 million cubic feet per day. The best results were obtained from exploration in Allegany County, where out of eight wells drilled to the Oriskany sandstone five were successful and showed a combined open-flow capacity of 107 million cubic feet. The Oriskany sandstone was encountered at a depth of 4500 to 4900 ft. In Steuben County, next east of Allegany County, two out of seven wells to the Oriskany proved productive, and one of these, in the town of Greenwood, on the Watkins structure, was probably the largest that has so far been opened in the state, with a reported yield of 35 million a day. In the central part of New York interest was awakened by the activity shown in exploring for gas in the Trenton limestone, in Camden, Florence and Rome townships, Oneida

Jan 1, 1936

By D. H. Newland

New York has a small but not insignificant place in the oil and natural gas industries of the United States. It has had a continuous record as an oil producer since 1872, with an aggregate yield of about 104,000,000 bbl. The reported output for 1935 was 4,237,000 bbl., a gain of more than 10 per cent for the year and a total that has been exceeded only in the early period of flush production half a century ago. The industry has been steadily building up since 1920 with the successful practice of the water drive, which has given a new lease of life to pools that had been practically drained of oil recoverable by pumping. An additional output of 2000 bbl. or more per acre is being procured by this method. Altogether the fields in New York State cover about 55,000 acres. Their limits are well defined and it is unlikely that they will be extended in the future, although there is some prospect of finding additional supplies by deeper drilling. The oil from New York is all classed as Pennsylvania grade, for which the recent price has been about $2.50 a barrel. It is refined at Olean, Wellsville and Bolivar, in the oil district, and partly in Pennsylvania refineries. Exploration for natural gas, outside of the established districts, was considerable during the year. Altogether 59 wells were drilled, distributed over 13 counties, of which 33 were listed as producers and 26 were dry. At the close of the year, 13 wells were in process of drilling. The 33 producing wells had a combined estimated flow of 278 million cubic feet per day. The best results were obtained from exploration in Allegany County, where out of eight wells drilled to the Oriskany sandstone five were successful and showed a combined open-flow capacity of 107 million cubic feet. The Oriskany sandstone was encountered at a depth of 4500 to 4900 ft. In Steuben County, next east of Allegany County, two out of seven wells to the Oriskany proved productive, and one of these, in the town of Greenwood, on the Watkins structure, was probably the largest that has so far been opened in the state, with a reported yield of 35 million a day. In the central part of New York interest was awakened by the activity shown in exploring for gas in the Trenton limestone, in Camden, Florence and Rome townships, Oneida

Jan 1, 1936

By R. A. L. Black, J. E. Jennings

The problems of slope stability in open cast mines are examined. A criterion, the instantaneous stripping ratio, is suggested for use in the design of pit slopes and as an index of control at all stages of the exploitation of the orebody. This criterion may also be related to safety and to the maximizing of profits. Two approaches to safe design of slopes, one from the point of view of soil mechanics and the other from the point of view of rock mechanics, are described and critically compared. The effect on slope stability of the regional tectonic stress field is discussed. Explanation is given of the application of the Terzaghi effective stress concept to problems in both soil and rock environments, including possible effects when borehole deformation techniques are used to measure stresses in rock in situ. A company embarking on open cast mining is faced with two basic questions: 1) will the venture be profitable and 2) can it be carried out with safety? The two questions are obviously interrelated because both depend upon the slope angles adopted for the pit. The cost of open cast mining depends largely upon the stripping ratio, defined as the volume of overburden that must be removed to the volume of ore recovered. The steeper the slope angles, the more favorable the stripping ratio, but the stability of the slopes, and therefore the safety of men and materials in the pit, require that the angles be made relatively flat. Consequently, the design depends upon a compromise: the slopes must be steep enough to result in economical mining and flat enough to ensure safety. Today there is a world trend towards deeper mining by open cast methods. This is mainly due to the higher cost of underground mining and the lower cost of open excavation resulting from the introduction of large modern earth and rock-moving machinery. Deeper open cast mining has led to a very great increase in the volumes of wasted overburden, and much thought is being given to the considerable economic benefits which would result if pit slopes could be made steeper by even one or two degrees. The result has been an increasing interest in research into slope stability problems in the expectation that the application of scientific principles will provide solutions leading both to economies and to more predictable operation of the mines. In at least four places, the U.S., Australia, Western Germany and Southern Africa, comprehensive investigations are at present in progress, and it is the object of this paper to review some of the more important aspects of these programs. RELATION BETWEEN ECONOMY OF OPERATION AND SLOPE ANGLES The main object of any industrial enterprise in a free economy is to make a profit. In mining, where profits must be made from a wasting capital asset, a further definition of the profit motive is imposed, namely that the economic aim should be to maximize the total possible profit. But since profits deferred for a number of years are not as valuable as profits that are immediately available, it is usual to discount deferred profits at some rate of interest which reflects their current or present value in the hands of the investor. Thus, in mining the logical aim can be defined more closely still: to maximize the present value of the total future profits. In commercial terms the present value represents the market value of the operation as a going concern. Many factors enter into the forecast of current and future profits. They include the volume of production, the price of the salable product and the cost of production. Current profits can be estimated with reasonable accuracy by the operating engineers; but it is the task of economists and management to assess future trends in the mineral markets and in the economy as a whole, and together with the engineers, they can then estimate the future cost and profitability of the mining operations. In open cast mining, the rate of ore production once decided on remains a virtually constant factor unless a major change in the capital structure of the mine is made. But one factor over which the operator has a considerable measure of control is the ratio of the volume of ore mined to the volume of waste over-

Jan 1, 1963

By M. L. Holzworth, Philip R. Sperry, Paul A. Beck

INTRODUCTION THE basic work of Z. Jeffries1,2,3 has long ago established the main features of grain growth in the presence of a dispersed second phase. Working with sintered specimens of initially fine grained tungsten, to which various amounts of thoria have been added, Jeffries found that grain growth was inhabited, that is, practically prevented, up to a certain annealing temperature. When this temperature, which increased with the thoria content, was exceeded, extremely large grains developed abruptly from the fine grained matrix. Such a "coarsening temperature" was later found by Gross mann13,14 in certain types of steel, while Bain showed" that in other steels grain growth was gradual, without inhibition and abrupt coarsening. Later work16,17,18,19,21 demonstrated the connection between coarsening and aluminum additions. The viewpoint that the direct cause of inhibition and coarsening in aluminum killed steels is a fine dispersion of aluminum oxide21 appears to be held quite generally, although some doubts have been voiced even very recently.20 In steels with Ti additions the titanium carbide phase is considered responsible for the inhibition effects found.20 The coarsening temperature increases, with the titanium content. That coarsening may occur, as a result of certain heat treatments, even in low carbon rimmed sheet steel, was shown by Samuels,22 He also detected coarsening in a steel ingot of similar composition, after giving it the same heat treatment as that used by him for the sheet material, In this instance the identity of the inhibiting phase has not been determined, However, Tangerding found 23 that even the few small carbide particles, which occur in carbonyl iron, have a very marked inhibitive effect. As a result of an oxidizing anneal at 850°C, large grains begin to form at the surface of the carbonyl iron specimen, and gradually grow inward as the subsurface oxidation of the carbide particles progresses and eliminates the obstruction, The carbide particles can be removed also by annealing in hydrogen, with similar results. But if the oxidizing anneal of 10 hr at 850°C in air, is followed by annealing in hydrogen for 75 hr at the same temperature, grain growth is more spectacular; usually the whole specimen is transformed into a single crystal (approx. 1,5 cm X 5 cm). The reversed procedure, that is, hydrogen annealing followed by oxidizing annealing leads to smaller grains. Tangerding arrived at the logical conclusion that there must have been in his specimens some additional obstruction to grain growth resulting from a minor impurity, other than carbon. It seems likely that this obstruction was caused by an oxide formed during the oxidizing anneal and gradually reduced during the subsequent hydrogen-annealing. Other instances of grain growth inhibition of varying severity, associated with a dispersed second phase, have been described by several authors. Notable examples: lead with 0.06 pct Cu or Ni,24 cartridge brass with 0.12 pct Cr,25 or with up to 0.15

Jan 1, 1948

By P. Pollard

A method has been developed for evaluating acid treatments in fractured limestone fields by breaking down pressure drawdown into three component parts: (I) pressure differcntial across "skin" near the borehole face, (2) pressure differential due to flow resistance in the coarse communicating fissures and (3) pressure differential between the fine voids and the coarse fissures. It is apparent that in most successful acid treatments the first term, skin resistance, has been reduced or eliminated. Further, it is often possible to estimate the volume of coarse fissures associated with the second term, coarse fissure flow resistance. In cases where this volume is comparable with practical acid volumes it seems likely that this resistance also may be attacked with a suitably retarded acid. INTROD UCTION Acid treatment has been successfully applied as a general practice in the limestone wells in the Mara/ Maracaibo districts of Venezuela for some 10 years. At the same time the need has been felt for a more precise method of: (1) evaluating the effect of an acid job and (2) selecting wells which should benefit from an acid treatment. The following method, based on an analysis of build-up curves for wells producing from fractured limestone, provides a means of forecasting the effect acid will have on a well and in many cases the probable order of production rate increase which may be expected. In certain cases it is also possible to calculate the fissure volume through which the acid has to be displaced for best results. Various approximations are introduced in the method, but within the limitations of these the analysis gives an indication of how a well, whether previously acidized or not, may be expected to respond to acid treatment. Suitable build-up curves cannot be obtained on "tight" wells which do not give sustained production and the method is not applicable to such wells. Figs. 1 through 7 illustrate various types of build-up curves obtained from limestone wells in Western Venezuela. Curves are included showing (1) both skin and coarse fissure resistance, (2) skin resistance only, (3 and 4) reduction of skin resistance by acidization, (5) fissure resistance only, (6) reduction of coarse fissure resistance by acidization, and (7) acidization failure. This theory has been successfully applied for over three years during which 22 acid treatments have been carried out specifically to reduce skin resistance and three treatments to reduce coarse fissure resistance. The method has been found to be a useful aid in the selection of wells for acidization.

By L. W. Strock

Metallurgists handling lead and zinc ores have long been familiar with the spectrograph as a routine analytical tool, as its earliest regular use by American industry was in controlling impurities of zinc metal and its alloys. This application has been extended to other metal industries on an extensive scale, accompanied by refinements of procedure to such an extent that a large part of some metals produced, especially magnesium, aluminum and steel, are checked only by spectrographic methods for conformity to specifications. The spectrographic analysis of ores and other poorly conducting powdered solids presents difficulties not encountered with metallic samples, which can be arced or sparked as self-electrodes or can be readily dissolved, so that their solutions can be analyzed, as in the American Society for Testing Materials standard methods for zinc and zinc-base alloys. Spectra of powdered solid samples can be prepared by using carbon electrodes provided with a crater of suitable size, into which the sample is packed. Ore samples and many other powdered solid materials usually analyzed in the chemical and metallurgical laboratory are more complex and varied in composition than samples of metals produced in large tonnages. 'lore preliminary work therefore is usually necessary in devising a spectrographic method for analyzing a given type of powdered sample than for analyzing metal samples, in order to use that method with confidence. The howledge that the standard samples and unknowns produce equivalent line intensities at equal concentration is the fundamental basis of any quantitative spectrographic method. On the other hand, powdered samples have an advantage over metals in that any desired number of chemical compounds can be mixed dry in any desired ratio to produce a synthetic standard. Expcrience has shown, however, that spectra of elements in finely divided compounds introduced into a standard in preparing a synthetic ore sample do not always behave in the electric arc in a manner that produces spectral line intensities similar to those observed at the same concentration in a natural mineral. In ore samples minor elements frequently are contained in the crystal lattice of larger particles of an abundant ore mineral. Their dissociation and volatilization from the sample into the arc then proceeds differently in the standard and sample, with resultant differences in intensity. During the past 10 years I have devised and applied several quantitative spectrographic methods for determining various elements in rocks and minerals in connection with studies on their geochemistry,' but the incentive has gradually changed since the summer 0. 1940 to the specific practical problem of searching for domestic sources of rare and stratcgic metals. The

Jan 1, 1949

By Arthur Green

A GROUP of 13 cities situated in Los Angeles and Orange counties in Southern California is engaged in constructing an aqueduct to carry water from the Colorado River at a point near Parker, Arizona, to a distribution point sear Riverside, California. The aqueduct will have a total length of approximately 241 miles, and is designed to deliver 1605 cu. ft. of water per second, or a little more than one billion gallons per day. The aqueduct crosses a barren, desert waste and the project includes approximately 91 miles of 16-ft. tunnel. The large amount of tunnel driving that has been done in this country in the past few years has resulted in some remarkable developments in equipment and methods. The building of the Colorado River Aqueduct, with its 91 miles of tunnels, has called on the best engineering knowledge in the country. New and better equipment has been designed for all phases of the work, and this equipment has been coordinated and adapted to the various conditions with a high degree of efficiency. The result has been that records for tunnel driving have been set under adverse natural conditions that exceed the estimates for progress under good conditions. All of the tunnels in the main aqueduct, except the Valverde and Bernasconi at the western end, have a finished diameter, inside the concrete lining, of 16 ft. Fig. 4 shows a section of the tunnel with the concrete lining in place. Fig. 5 illustrates the finished tunnel in three typical sections. The standard tunnel grade is 3.432 ft. per mile in the 16-ft. tunnels, but the Valverde and Bernasconi tunnels have a steeper grade and a finished diameter of 15 ft. 3 in. The rough bore of the large main aqueduct tunnels averages 12.95 solid cubic yards of material per foot of advance in timbered sections and 10.76 solid cubic yards per foot in unsupported sections.

Jan 1, 1936

By Dwain K. Butler

INTRODUCTION Characterization of a site for the prediction and simulation of dynamic events requires the determination of mechanical properties of the rock at stress/strain levels and rates and at a scale appropriate for the events and critical structures involved. The structures of interest can be on the surface, underground, or designed to impact and penetrate into the site (projectiles). Dynamic events of interest are equally diverse: seismic waves from distance earthquakes or explosions; close-in phenomena associated with earthquakes and explosions; vibrations associated with heavy equipment or machinery; and stress transients associated with impact and penetration. The complexity of site characterization depends on two factors not specifically related to the nature of the site itself: the stress levels generated by the dynamic event and the sophistication of the prediction and simulation techniques. For very high stress levels, such as occur near a nuclear detonation, and for low stress levels, such as occur during seismic wave propagation, site characterization is simplified, and often certain details of the site are not particularly important, such as shear strength variations in the case of very high stress levels. In the intermediate stress range, however, all descriptive relations are non- linear, a complete finite strain constitutive model is required, and all details of the site, such as lithology and fracture distribution, become important. The site characterization must be complete enough to support the most sophisticated prediction and simulation technique that will be applied to the analysis of the dynamic event. The procedures of site characterization are illustrated in this paper by a specific dynamic event, projectile impact and penetration, and a specific site, an outcrop of Dakota Sandstone near San Ysidro, New Mexico. The structure of interest was the projectile itself: nominally, 1.5 m in length, 0.165 m in diameter, 180 kg

Jan 1, 1984

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 A. E. Moss, J. K. Gustafson

MEASURED in terms of ore tonnage, the New Quebec and Labrador iron ore fields promise to rank with the greatest iron ore districts of the world. Over 400 million tons of high-grade ore for direct shipping have been discovered to date. Much greater amounts of lower-grade beneficiating ores are indicated by outcrops. Many hundreds of square miles of iron formation await testing. By 1954 iron ore will begin to move towards American blast furnaces, and shortly thereafter the annual rate of production is expected to reach 10 . million tons. To bring this vast project into being over $200,000,000 will have been spent for exploration and development, mining equipment, hydro plants, townsites, the building and the equipping of . a 360-mile railroad, and the construction of docks and ore-handling facilities. The most important iron ore deposits are located over 300 miles from tide water, see frontispiece and also Fig. 1. The frontispiece shows principal sources of iron ores and manganiferous iron ores for the U. S. and Canadian steel industry, and the major smelting districts are shaded on the map. No navi- gable rivers lead into the interior. When work was . commenced on this project there were no roads, no railroads, no communication ,system, no inhabitants, and no adequate maps either topographical or geological. The geological field season was limited to approximately 100 days per season. The obstacles facing this enterprise were many and varied. Its success will be due to the integrated team work of people of diverse skills. Explorers, Indian guides, prospectors, geologists, surveyors, mechanical, civil, electrical, and mining engineers,

Jan 1, 1954

By P. E. Baker

An experimental study of heat flow in steam flooding was carried out with steam displacing water in a plane-radial fluid-flow model. Temperature distributions in the model reservoir, overburden, and substratum were measured at frequent intervals during flooding by means of a fixed array of thermocouples. Heat losses to overburden and substratum and the division of heat between the steam and hot-water zones in the reservoir were calculated from the temperature data by performing numerical integrations over the appropriate volumes. Temperature profiles and heat distribution results are presented. Some results were (1) the fraction of injected heat that is lost to overburden and substratum, when expressed as a function of time, did not depend on injection rate; (2) a significant portion of the injected heat was contained in the hot-water zone ahead of and underlying the steam front in the reservoir. The division of heat between the steam and hot-water zones did depend on injection rate; and (3) considerable gravity override was observed. The experimental results are compared with those of several published theoretical studies of heat transfer in hot-fluid injection; approximate agreement on heat losses is found with some of the most idealized theories. A valid comparison cannot be made in regard to steam us hot-water zone; basic interpretation of the hot-water zone, in terms of a vertical steam front, is clouded by gravity override in the experiments. INTRODUCTION The experimental study reported here primarily concerns two problems of heat transfer in steam flooding that have economic and engineering importance. These are (1) the fraction of injected heat lost to the overburden and substratum, and (2) the division of the remaining heat between a zone containing steam and a zone of hot water at lower-than-boiling temperature. The volume of the steamed region, which has a direct effect on oil recovery, can be calculated readily from these results. Several valuable theoretical studies have been published on this problem, but no experimental tests of the theories have previously appeared. Tests were needed because the effects of the necessary simplifications in the theories could not be determined otherwise. The basic, untested theoretical problem is the effect of "decoupling" heat and mass transfer, and the resulting inability to include the effects of heat transfer and condensation on fluid flow. The theoretical problem solved so far has been a heat transfer problem in which fluid is present as a heat carrier and flows in a stipulated manner, either linear or plane-radial. The simplifications that have sometimes been made in regard to thermal conductivity by, for example, Marx and Langenheim,l Lauwerier2 and Thomas3 apparently do not have an important effect on heat loss calculations, although the results of the different methods disagree to a certain extent, as shown by Spillette4 and by Ramey.5 A recent paper by the author6 compared the results of experiments in hot-water flooding with several theoretical results and showed a rather poor agreement. It will be seen that the experimental heat loss results for steam flooding, however, show acceptable agreement. These comparisons are discussed in a later section. EXPERIMENTAL APPARATUS AND PROCEDURE The system studied was one in which a sand pack, initially water saturated and at a uniform temperature, was flooded with steam at a constant rate and temperature. The temperature distribution in the "reservoir" and adjacent "strata" was measured with an array of thermocouples, and heat losses were determined from these measurements. The sand pack contained no oil because the only concern of the experiments was heat flow, and it was important to have the flow pattern as simple

Jan 1, 1970

By G. W. Brock

Experiments in the form of aging of overstrained tension specimens and elevated temperature tension testing, have been carried out on recrystallized arc-cast molybdenum. The aging behavior of molybdenum was found to be strongly dependent on the degree of plastic strain present in the lattice: the reason for this being the low solid solubility for the common interstitial elements in molybdenum. GEORGE W. BROCK, formerly Research Associate, Department of Theoretical and Applied Mechanics, University of Illinois, Urbana, III., is Research Associate, Department of Engineering Sciences, IBM Research Center, Yorktown Heights, N. Y. Manuscript submitted January 19, 1961. IMD THE term strain aging is familiar in connection with the recovery of the yield point in mild steel after tensile overstraining, and there are other instances where it is known to exert an appreciable effect on mechanical properties. For example, steel exhibits a greater tensile strength at mildly elevated temperatures than at room temperature and serrated stress-strain flow curves occur under certain conditions. It has been known for a number of years that the phenomenon of strain aging is directly connected with the presence of carbon and nitrogen in the lattice; and extremely small amounts of either element are sufficient to produce the effect. In this study, the aging behavior of overstrained tensile specimens of recrystallized molybdenum has

Jan 1, 1962

By R. F. Mehl, C. S. Barrett, A. H. Geisler

THE studies of the mechanism of precipitation and of the resulting property changes in aluminum-silver alloys1-3 have presented some new concepts of the aging reaction-concepts that may be fundamental in establishing a complete quantitative theory of age-hardening. With both aluminum-copper and aluminum-silver alloys, thin platelike aggregates form parallel to the Widmanstätten planes of precipitation.1,4 These platelets grow in lateral dimensions and in thickness with aging time until they are thick enough to produce an X-ray diffraction line pattern. Their structure is that of a transition lattice which is coherent with the matrix, since the atomic spacings in the matrix and the precipitate are the same on each side of their common interface.2,4 The equilibrium precipitate forms later from and at the expense of the transition lattice. Since age-hardening occurs during the formation and growth of the transition lattice, the major contributor to the hardening no doubt is the stress condition in the matrix resulting from the matrix holding the precipitate in the coherent condition. The development of these stresses also appears to be responsible for an increase in the electrical resistance superimposed on the normal decrease resulting from a change in the concentration of the matrix during aging.3 The two consecutive reactions constituting the aging process are accompanied by characteristic microstructural alterations. The initial precipitation process results in the formation of a Widmanstätten figure, while the later transformation of the transition lattice to the equilibrium lattice is accompanied by a coalescence, in the case of aluminum-copper alloys,5 and by the appearance of light areas at the grain boundaries with aluminum-silver alloys showing a structural rearrangement of matrix and precipitate.3 This latter reaction is similar microscopically to the so-called "discontinuous precipitation." Possibly discontinuous precipitation is a process that often if not always follows true precipitation of a coherent lattice and during which the transformation of the coherent transition lattice to the equilibrium lattice takes place accompanied by matrix recrystallization.3 EXPERIMENTAL PROCEDURE The alloys were made using 99.97 per cent Al or distilled magnesium, with

Jan 1, 1943