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By H. L. Gilbert, C. T. Anderson, W. J. Kroll

In a previous paper,' the use of a split graphite tube resistor as a heater element for high-temperature furnaces has been described. The principal advantages of this type of construction are: I. The quadruple resistance or voltage compared with the top-bottom clamp resistor furnace. 2. Free expansion of the resistor. 3. The ease of protection from oxidation by air. 4. The firmness by which it may be held in the compact split clamp. This construction appeared to be well adapted for the fusion of high melting metals which require fusion in a vacuum. Zirconium metal had previously been melted at the Albany Laboratory of the Bureau of Mines in a vacuum arc furnace on a water-cooled plate, using a movable tungsten top electrode.% When larger furnace capacities were desired, this type of construction proved to have its limitations as the largest tungsten rods available were about 7/8 in. in diameter. The supply of direct current of high amperage for producing the desired arc characteristics was also not available. Considerable difficulty was also found in compensating the atmospheric pressure on the flcxible tubing of the movable electrodc, at the same time keeping its movement sufficiently free to enable the striking of an arc on any part of the metal briquet. Among the various materials used for the electrodes in conducting experiments in the vacuum arc furnace was graphite. It was found that zirconium fused in a graphite cup with a carbon arc was contaminated to only 0.2 pct carbon. It was therefore decsed to melt zirconium directly in graphite crucibles. A high-frequency furnace was first used in the attempt to melt the zirconium in graphite crucibles. The high-frequency heating coil was placed outside a silica tube which was evacuated by means of an oil diffusion pump backed up by a mechanical pump. The graphite crucible was thoroughly degassed at 19oo"C before use. Considerable difficulty was experienced in operating at such temperatures in vacuo because, as shown by Zintl,3 carbon vapor formed and reacted with silica accortling to the reaction: SiO² + C = SiO + CO. The silicon monoxide which is volatile at these high temperatures reacted with the zirconium, thereby contaminating it with silicon and oxygen. The presence of carbon monoxide was detected by means of a gas discharge tube placed in the vacuum system as indicated by the pale blue glow of the tube as soon as carbon vapor started to react with the hot silica. The reaction between the carbon vapor and hot silica was avoided by the use of split cylindrical molybdenum shields which were inserted between the graphite crucible

Jan 1, 1949

By B. M. Larsen, T. E. Brower

In two previous paperslJ dealing with the carbon-oxygcn reaction, and the simultaneous content of each, in liquid steel in the furnace, we have made use of the quantity A[O], defined as the excess oxygen beyond what would be in equilibrium with carbon then present if the pressure of carbon monoxide were I atm.; that is, if [C] X [O] is taken as 0.00222, A[O] = [O] - 0.0022[C] where [O] is the percentage of oxygen by weight as measured by the method described earlier.3 This quantity ?[O] proves to be substantially independent of carbon content over the range 0.08 to I,z per cent, as well as of the basicity of the slag, and is nearly always within the limits o.o15 to o.oz5 per cent when the bath is boiling normally and is in what we have termed a steady state, Apparently it must be at least about 0.014 per cent before boiling occurs; but this threshold value seems to depend upon the ease of bubble formation at the metal-hearth interface, hence upon the condition of the surface of the hearth. In any case, ~(01, on the average, changes considerably following any disturbance of the bath, as by addition of ore. The present paper deals with the average changes in A[O] level following addition of spiegel or crop ends, or after procedures to promote stirring, or by tapping of the steel from the furnace. The observations were made on a large number of commercial heats, and consequently are subject to the influence of various disturbing factors; the results have the compensating merit of showing the consistency obtainable under the limitations imposed by practical operation. Variability of Excess Oxygen in Normal Open-hearth Operation The preceding genera' statements refer to the average value of A[0] particularly in heats that are boiling actively; on individual heats, which are less active, there may be a variable time lag between the disturbance and its effect, which complicates the interpretation of what is going on. For instance, if in the normal refining process boiling is sluggish, the slag usually is gaining Oxygen from the gas phase above it, Or from added Ore$ faster than it is losing oxygen to the metal; Yet when the bath starts to boil vigorously, the opposite condition may prevail for Some time. The consequence of this lag is a variation of A[o], the interpretation of which in a sing1e heat may not be immediately obvious. This condition is illustrated in Figs. I and 2. In Fig. 1, A[0] at the beginning of the test period was near the lower limit of its usual range (dashed lines) in the steady state as a consequence of the lime boil, which had ended about as indicated. The bath is now cold, carbon drop is slow, and the first small orc feed causes only a small rise in A[O]; as the temperature rises and as lime dissolves in the slag, and the bath becomes more active, the

Jan 1, 1948

By B. M. Larsen, T. E. Brower

In two previous paperslJ dealing with the carbon-oxygcn reaction, and the simultaneous content of each, in liquid steel in the furnace, we have made use of the quantity A[O], defined as the excess oxygen beyond what would be in equilibrium with carbon then present if the pressure of carbon monoxide were I atm.; that is, if [C] X [O] is taken as 0.00222, A[O] = [O] - 0.0022[C] where [O] is the percentage of oxygen by weight as measured by the method described earlier.3 This quantity ?[O] proves to be substantially independent of carbon content over the range 0.08 to I,z per cent, as well as of the basicity of the slag, and is nearly always within the limits o.o15 to o.oz5 per cent when the bath is boiling normally and is in what we have termed a steady state, Apparently it must be at least about 0.014 per cent before boiling occurs; but this threshold value seems to depend upon the ease of bubble formation at the metal-hearth interface, hence upon the condition of the surface of the hearth. In any case, ~(01, on the average, changes considerably following any disturbance of the bath, as by addition of ore. The present paper deals with the average changes in A[O] level following addition of spiegel or crop ends, or after procedures to promote stirring, or by tapping of the steel from the furnace. The observations were made on a large number of commercial heats, and consequently are subject to the influence of various disturbing factors; the results have the compensating merit of showing the consistency obtainable under the limitations imposed by practical operation. Variability of Excess Oxygen in Normal Open-hearth Operation The preceding genera' statements refer to the average value of A[0] particularly in heats that are boiling actively; on individual heats, which are less active, there may be a variable time lag between the disturbance and its effect, which complicates the interpretation of what is going on. For instance, if in the normal refining process boiling is sluggish, the slag usually is gaining Oxygen from the gas phase above it, Or from added Ore$ faster than it is losing oxygen to the metal; Yet when the bath starts to boil vigorously, the opposite condition may prevail for Some time. The consequence of this lag is a variation of A[o], the interpretation of which in a sing1e heat may not be immediately obvious. This condition is illustrated in Figs. I and 2. In Fig. 1, A[0] at the beginning of the test period was near the lower limit of its usual range (dashed lines) in the steady state as a consequence of the lime boil, which had ended about as indicated. The bath is now cold, carbon drop is slow, and the first small orc feed causes only a small rise in A[O]; as the temperature rises and as lime dissolves in the slag, and the bath becomes more active, the

Jan 1, 1948

By J. E. Burke, C. S. Barrett

The fine lines shown in Fig I are typical of markings that ma): be detected after polishing and etching deformed specimens of alpha brass and other alloys. Although they have long been the subject of discussion by metallurgists their nature is still uncertain and the names that have been applied: to them, such as deformation line4 or strain markinas, indicate this uncertainky. In this paper which repotts the results of a furthcr investigatinn of their nature, they will be called strain mxrkings. Introduction Mathewson and Phillips1 described strain markinps in 1 916 and concluded that they appear only after 20 pet deformation. They objected to the markings being called slip tines believing this term should be sewrved for surface markings protluced by plastic deformntion. In 1921. vogel² described similar striations which appeared after polishing and etching the roughly ground surface of numerous alloys. He reported that the markings were crystallo-graphic in nature, and since they resemble Seumann hands in iron, at least superficially, he assumed them to be mechanical twins. In 1928, Matherwson reported work by Phillips which indicated that the lines were more readily produced by impact than by slow deformation and that in many cases the twins inside recrystallized grains were parallel to strain markings in the original deformed grains. This was taken as cvirlence that the markings coalesce into anncaling twins. and hence that they themselves are mechanical twins. Many attempts have been made to demonstrate directly that the markings are mechanical twins. In 1934, Samans described the results of X ray studies of two defomed crystals of alpha brass. Evidence was obtained which could be interpreted to indicate that the strain markings arc mechanical twins, and this remains the only direct evidence to this effect. Several other attempts to obtain similar evidence by X ray diffraction have failed5.8.7 although in no Ease was the original method of Samans employed. An

Jan 1, 1949

By C. S. Barrett, J. E. Burke

The fine lines shown in Fig I are typical of markings that ma): be detected after polishing and etching deformed specimens of alpha brass and other alloys. Although they have long been the subject of discussion by metallurgists their nature is still uncertain and the names that have been applied: to them, such as deformation line4 or strain markinas, indicate this uncertainky. In this paper which repotts the results of a furthcr investigatinn of their nature, they will be called strain mxrkings. Introduction Mathewson and Phillips1 described strain markinps in 1 916 and concluded that they appear only after 20 pet deformation. They objected to the markings being called slip tines believing this term should be sewrved for surface markings protluced by plastic deformntion. In 1921. vogel² described similar striations which appeared after polishing and etching the roughly ground surface of numerous alloys. He reported that the markings were crystallo-graphic in nature, and since they resemble Seumann hands in iron, at least superficially, he assumed them to be mechanical twins. In 1928, Matherwson reported work by Phillips which indicated that the lines were more readily produced by impact than by slow deformation and that in many cases the twins inside recrystallized grains were parallel to strain markings in the original deformed grains. This was taken as cvirlence that the markings coalesce into anncaling twins. and hence that they themselves are mechanical twins. Many attempts have been made to demonstrate directly that the markings are mechanical twins. In 1934, Samans described the results of X ray studies of two defomed crystals of alpha brass. Evidence was obtained which could be interpreted to indicate that the strain markings arc mechanical twins, and this remains the only direct evidence to this effect. Several other attempts to obtain similar evidence by X ray diffraction have failed5.8.7 although in no Ease was the original method of Samans employed. An

Jan 1, 1949

By John M. Sharp

John M. Sharp, Jr. (Assistant Professor of Geology, University of Missouri, Columbia, Mo.)-Geothermal gradient and surface temperature data anomalies are potentially useful tools in mineral exploration, These data, however, may reflect a number of geologic and hydrologic processes as well as the thermophysical properties of the geologic materials. The author presents a relatively simple model which may be of value in mineral exploration. The lack of consideration of other processes, however, limits its usefulness. For instance, because of erosion or sediment deposition over geologic time the land surface must be considered a moving boundary in such a model. Evaluation of this effect coupled with annual surface temperature and thermal conductivity variations can result in temperature profiles such as shown in [Figs. 4 to 7]. These effects and others, such as ground-water movement," must be considered and filtered from the data before proper interpretation is possible. Another assumption which should have been discussed is, why were the observed mean surface temperatures not used for extrapolation of the gradients in [Figs. 4, 6, and 7?] Conductive heat transport responds to the actual boundary (land surface) temperature, not to theoretical temperatures in the absence of perturbations. Benfield presents a theoretical model for calculating perturbations in the geothermal gradient for erosion and sedimentation. The temperature (T) at any time (t) and any depth below the surface (x) is given by [ ] where T is the mean surface temperature, G, the geothermal gradient, v, the rate of erosion (or sedimentation),[ ], the long-term rate of change of T0, and k is the thermal diffusivity of the rock. Using the author's values and a rate of erosion of 1.54 cm per yr for a period of 10,000 yr, a thermal profile as shown in [Fig. 10] will be generated. A thermal diffusivity of 0.0164 sq cm per sec was used, corresponding to a thermal conductivity of 0.0082 cal per cm per sec per C. In [Fig. 11], a sediment deposition rate of 3.0 cm per yr for a period of 1000 yr was used to generate the subsurface temperature profile. A surface temperature of 24.3°C was used, as specified in [Fig. 9, 7], was set equal to zero for both cases. Superposition on the generated profiles in [Figs. 10 and 11] of the annual surface temperature variation perturbation (which may be calculated in a number of ways) will yield profiles similar to those in [Figs. 4 and 7]. Similar profiles can also be produced by regional ground-water flow. Models like the author's can be of value in mineral exploration. Other processes, however, which affect surface temperatures and gradients must first be considered, calculated, and filtered from the data if anything but the crudest qualitative interpretation is to be made. Robert C. Edmiston (Author's reply)-Professor Sharp has raised three objections to my interpretation of the subsurface temperature data I collected at Silver Bell. These are: 1) No correction was made for erosion or sedimentation,

Jan 1, 1977

By William A. West

One manifestation of anelastic properties in solids is the mechanical elastic aftereffect, which may be described briefly as follows: If a stress is applied to a solid body, a deformation or strain is produced. On removal of the stress, this deformation disappears, at least in part. As a first approximation, this appearance or disappearance of deformation usually has been considered instantaneous. Actually, however, for a very wide variety of substances, on application of stress the instantaneous deformation is followed by a further slow yielding, which continues, although at a rapidly diminishing rate, for as long as the stress is applied. Similarly, on removal of the stress, the instantaneous recovery from deformation is followed by a further slow recovery, which continues, although at a rapidly diminishing rate, often for a long time. This latter phenomenon has been called the "elastic after-effect." Experiments upon the elastic after-effect in metals, when properly designed and when properly interpreted, are capable of giving quite precise information regarding the relation between stress and strain in the various constituent parts of the metal. For example, if certain parts of the metal, such as grain boundaries or slip bands, behave in a viscous manner—that is, if therein—the relaxation spectrum will contain lines or bands associated with the relaxation of shear stress within these parts. No attempts have heretofore been made to utilize elastic after-effects for obtaining such detailed information. The purpose of the present paper is to explore the possibilities of properly designed and interpreted experiments on the elastic aftereffect in metals. Since new procedures and principles are employed in this study, an attempt has been made to record each step taken. Elastic after-effect observations are susceptible of simple interpretation only when the stress level employed is so low that all effects are linear with the stress. Just how low the stress level must be can he determined only by experiment. An advnntage, other than simple interpretation, is associated with low stress levels. When all effects are linear, derived quantities, such as the relaxation spectrum, are independent of the stress distribution. It is, furthermore, possible to employ the type of deformation that is most convenient from the experimental standpoint; for example torsion. It appears that in experiments involving both loading and unloading the following would be observed: I. Instantaneous deformation, recoverable instantaneously in whole, or in part. 2. Delayed deformation, recoverable slowly in whole, in part, or not at all. 3. Permanent deformation, the difference between total deformation and total recovery. In the work here described, unloading experiments only were made. Wires were

Jan 1, 1947

By William A. West

One manifestation of anelastic properties in solids is the mechanical elastic aftereffect, which may be described briefly as follows: If a stress is applied to a solid body, a deformation or strain is produced. On removal of the stress, this deformation disappears, at least in part. As a first approximation, this appearance or disappearance of deformation usually has been considered instantaneous. Actually, however, for a very wide variety of substances, on application of stress the instantaneous deformation is followed by a further slow yielding, which continues, although at a rapidly diminishing rate, for as long as the stress is applied. Similarly, on removal of the stress, the instantaneous recovery from deformation is followed by a further slow recovery, which continues, although at a rapidly diminishing rate, often for a long time. This latter phenomenon has been called the "elastic after-effect." Experiments upon the elastic after-effect in metals, when properly designed and when properly interpreted, are capable of giving quite precise information regarding the relation between stress and strain in the various constituent parts of the metal. For example, if certain parts of the metal, such as grain boundaries or slip bands, behave in a viscous manner—that is, if therein—the relaxation spectrum will contain lines or bands associated with the relaxation of shear stress within these parts. No attempts have heretofore been made to utilize elastic after-effects for obtaining such detailed information. The purpose of the present paper is to explore the possibilities of properly designed and interpreted experiments on the elastic aftereffect in metals. Since new procedures and principles are employed in this study, an attempt has been made to record each step taken. Elastic after-effect observations are susceptible of simple interpretation only when the stress level employed is so low that all effects are linear with the stress. Just how low the stress level must be can he determined only by experiment. An advnntage, other than simple interpretation, is associated with low stress levels. When all effects are linear, derived quantities, such as the relaxation spectrum, are independent of the stress distribution. It is, furthermore, possible to employ the type of deformation that is most convenient from the experimental standpoint; for example torsion. It appears that in experiments involving both loading and unloading the following would be observed: I. Instantaneous deformation, recoverable instantaneously in whole, or in part. 2. Delayed deformation, recoverable slowly in whole, in part, or not at all. 3. Permanent deformation, the difference between total deformation and total recovery. In the work here described, unloading experiments only were made. Wires were

Jan 1, 1947

By Frank Clemes Smith

The study of the so-called refractory gold-ores of the Potsdam sandstone, ores which are probably of wider occurrence and of much greater economic importance in the Black Hills than is generally supposed, has led the writer to formulate in the present paper some of the results obtained in the course of a special examination of these particular ores, conducted at the State School of Mines at Rapid City, So. Dak. Various circumstances have interrupted the work, and it will easily be seen that relatively little has yet been accomplished; but it is hoped that this little may be of sufficient interest to justify a later supplement. Tellurium, discovered by Muller von Reichenstein in 1781, is generally classed as a very rare metal; it is further mentioned by one of our late writers as " of comparatively little importance," and as obtained from its ores by a " complicated process.'' Concerning its rarity, we have some trustworthy evidence below. Its commercial importance, particularly in connection with electrical appliances, has been passed upon by Mr. Edison ; * and it is certain that, in some metallurgical processes for the treatment of gold- and silver-ores, it may be saved as a byproduct at a relatively reasonable expense. The importance of tellurium as a mineralizing agent is emphasized by the remarks of one of our leading metallurgists,jwho, in his own practice and by a wide series of experiments, has found its occurrence to be much more general than has been supposed. Recently the same writer has discussed the occurrence of tellurides and oxidized tellurium compounds in the gold-ores of Cripple Creek, Colo., and in those of the Black

Jan 1, 1897

By Frank C. Canney

The word "other" in paragraph 4, line 11, column 1, page 205, should read "over;" the correct version of reason 2, this paragraph, is: 'L. . . 2) to evaluate the usefulness of certain geo-chemical techniques, V. C. Kennedy and S. W. Hobbs of the USGS had already studied the distribution of copper, lead, and zinc in the soils (both in background areas and over veins) and in the water and plants, providing a criterion for measuring the magnitude and effect of soil contamination; ...9 On page 206, in the top left hand corner of Fig. 1 (in the area bounded by 47°35' and 116°10), the reference to Fig. 3 is incorrect. The area of Pine Creek, South Fork Coeur d'Alene River, and portion of Big Creek (the area which includes, from left to right, Kingston, Pinehurst, Smelterville, and Kellogg) should be identified as that of Fig. 2A. The headings for columns 1, 3, and 4, Tables I and 11, page 209, column 2, were reversed when the paper was printed. The corrected tables are:

Jan 1, 1961

By SME

"Comparison of Secondary Fe-Mn Oxides in Fracture Coating and Heavy-Mineral Concentrates as Sampling Media, Silver City Mining Region, New Mexico," a technical paper, appeared in the Aug. 1983 issue of the magazine. In Table 1, page 1182, the correct sequence of the first five metals in column 1 (Elements) should read: Zn, Pb, Cu, Fe, and Mn under "Central District" and Zn, Fe, Pb, Cu, and Mn under "Pinos Altos District." The published table shows the sequences transposed under the opposite districts. All other columns and sequences read correctly.

Jan 1, 1984

By L. F. Mondolfo

R301 is a clad aluminum alloy, composed of a core of a duralumin-type alloy clad with a magnesium silicide alloy. It differs from other well-known clad alloys in that the cladding and the core respond to the same heat-treatments. and therefore the cladding contributes appreciably to the mechanical properties of the material. In Table I are reported the compositions of the core and cladding alloy for the material used for the experiments. Table i.—Chemical composition of R~OI Used for the Experiments Element Core Cladding Cu........................ . 0.01 Fe......................... . 0.42 Si......................... 0. 0.71 Mg........................ . 0.99 Mn ........................ . 0.54 In clad aluminum alloys where the core contains copper and the cladding does not, at elevated temperatures the copper tends to diffuse from the core through the cladding. This fact is well known and many investigations have been conducted to determine the features of this diffusion. Most of those investigations cover materials clad with pure aluminum; the present investigation covers a material clad with an alloy. Since the cladding thickness on R~OI varies with the gauge, as shown in Table 2, several gauges were investigated. Material and Procedure he material used was sheet of the following gauges: o.o2~, 0.040, 0.064, 0.102, 0.170 Cut in pieces approximately 3 by 5 in., it was in the cold-rolled state and was soaked for increasing times at the following temperatures: glo°F., 940°F., 970°F. A Lindberg cyclone furnace was used for the experiments. The procedure was as follows: The furnace was started empty with controlling pyrometer set at the determined temperature. After the furnace had reached that temperature, it was run for some 20 to 30 min. empty, in order to allow the temperature inside to become stabilized. Then the first samples were introduced. A load thermocouple, with recording pyrometer, was connected with the sample of the heaviest gauge. About 10 min. was required for the material to reach temperature and the soaking time was counted from that point. After zoo min. soaking, the second group of samples was introduced without stopping the furnace. After 200 min. more, the third group of samples was introduced, and so on, until the last sample had been introduced. Every time the furnace was opened and new samples were added, a drop of temperature was registered by the thermocouple connected with the material

Jan 1, 1946

By L. F. Mondolfo

R301 is a clad aluminum alloy, composed of a core of a duralumin-type alloy clad with a magnesium silicide alloy. It differs from other well-known clad alloys in that the cladding and the core respond to the same heat-treatments. and therefore the cladding contributes appreciably to the mechanical properties of the material. In Table I are reported the compositions of the core and cladding alloy for the material used for the experiments. Table i.—Chemical composition of R~OI Used for the Experiments Element Core Cladding Cu........................ . 0.01 Fe......................... . 0.42 Si......................... 0. 0.71 Mg........................ . 0.99 Mn ........................ . 0.54 In clad aluminum alloys where the core contains copper and the cladding does not, at elevated temperatures the copper tends to diffuse from the core through the cladding. This fact is well known and many investigations have been conducted to determine the features of this diffusion. Most of those investigations cover materials clad with pure aluminum; the present investigation covers a material clad with an alloy. Since the cladding thickness on R~OI varies with the gauge, as shown in Table 2, several gauges were investigated. Material and Procedure he material used was sheet of the following gauges: o.o2~, 0.040, 0.064, 0.102, 0.170 Cut in pieces approximately 3 by 5 in., it was in the cold-rolled state and was soaked for increasing times at the following temperatures: glo°F., 940°F., 970°F. A Lindberg cyclone furnace was used for the experiments. The procedure was as follows: The furnace was started empty with controlling pyrometer set at the determined temperature. After the furnace had reached that temperature, it was run for some 20 to 30 min. empty, in order to allow the temperature inside to become stabilized. Then the first samples were introduced. A load thermocouple, with recording pyrometer, was connected with the sample of the heaviest gauge. About 10 min. was required for the material to reach temperature and the soaking time was counted from that point. After zoo min. soaking, the second group of samples was introduced without stopping the furnace. After 200 min. more, the third group of samples was introduced, and so on, until the last sample had been introduced. Every time the furnace was opened and new samples were added, a drop of temperature was registered by the thermocouple connected with the material

Jan 1, 1946

By H. O. Hofman

In the blast-furnace smelting of lead, copper and other non-ferrous metals, the largest part of the product obtained is slag. Its formation consumes more of the heat-energy of the fuel charged than any other chemical reaction that takes place. It is therefore of importance to know at what temperatures the different slags will form, so as to be able to choose in a given case the slag that will form at the right point in the operation, will keep the products thoroughly fluid, so as to insure a satisfactory separation, and will permit the consumption of fuel to be reduced to the lowest practicable point. While practical experience has brought out in a general way the leading differences as to the formation-temperatures of Rome silica—iron —lime slags, accurate details are still wanting. The object of the investigation here described was to supply some of these.* Prominent among the men who have worked on the fusibility of silicates are Lampadius, † Sefström,‡ Berthier,§

Jan 1, 1900

By John O. Farmer

The wire-line tubing perforator is a mechanically operated tool that is run on an ordinary steel measuring line into the tubing of a well, under pressure, to drive into the wall of the tubing, and securely lock in place, a tapered, cylindrical insert containing an orifice. Use of the perforator obviates the necessity of pulling and rerunning the tubing to install jet collars or flow valves, reduces the cost, and simplifies the task, of placing an oil well on gas-lift operation. More important, however, is the use of the tool with a removable check valve and stop, to provide a means of washing drilling mud from the annulus between the tubing and casing, and to complete the well for gas lift operation without exposing the producing formation to the mud column and without moving the tubing string. This paper discusses the origin, development, and mechanics of the wire-line perforator, the various purposes for which the tool was designed, and the method of selecting orifice sizes for any depth, and gives the results obtained thus far in practical application. Origin and Development Several years ago, a tool that could be lowered on an ordinary steel measuring line into the tubing of a well under pressure was designed and constructed for the purpose of punching a hole in the tubing walls above a shale bridge that had completely plugged the tubing of a well in the Long Lake field, East Texas. The well was in a low, swampy area, which excessive rainfall had caused to be in- accessible by car or truck for about four months. The only equipment at the well site consisted of an ordinary steel wire line that had been carried there to measure the depth of the bridge. Since a pulling unit could not be moved to the well site, and as the pressure on the casing was 2100 lb. per sq. in., it became apparent that the only way out of the predicament was to make a perforating tool that could be lowered into the tubing on a measuring line and operated under Pressure. Thus, the first wire-line tubing perforator was designed and built as an expedient, and was not used extensively until it had been redesigned to meet more frequent and increasingly urgent needs. Until recently, it was necessary to pull the tubing to install jet collars or flow the when a well was to be placed On gas lift. Because most companies either maintained or had access to pulling units and crews for this work, little or no thought had been given to eliminating or even simplifying this task. When the manpower and steel shortage became so acute, however, many operators suddenly found themselves without facilities to equip their wells for gas lifting. The wireline tubing perforator already had been tried and proved successful, therefore operators immediately requested its use to punch gas-jet holes in the tubing, to eliminate the pulling and running of tubing strings. The first deficiency revealed by more general use of the perforator lay in the inability to regulate the size of the hole punched through the tubing. The size could not be controlled to any degree of

Jan 1, 1946

By John O. Farmer

The wire-line tubing perforator is a mechanically operated tool that is run on an ordinary steel measuring line into the tubing of a well, under pressure, to drive into the wall of the tubing, and securely lock in place, a tapered, cylindrical insert containing an orifice. Use of the perforator obviates the necessity of pulling and rerunning the tubing to install jet collars or flow valves, reduces the cost, and simplifies the task, of placing an oil well on gas-lift operation. More important, however, is the use of the tool with a removable check valve and stop, to provide a means of washing drilling mud from the annulus between the tubing and casing, and to complete the well for gas lift operation without exposing the producing formation to the mud column and without moving the tubing string. This paper discusses the origin, development, and mechanics of the wire-line perforator, the various purposes for which the tool was designed, and the method of selecting orifice sizes for any depth, and gives the results obtained thus far in practical application. Origin and Development Several years ago, a tool that could be lowered on an ordinary steel measuring line into the tubing of a well under pressure was designed and constructed for the purpose of punching a hole in the tubing walls above a shale bridge that had completely plugged the tubing of a well in the Long Lake field, East Texas. The well was in a low, swampy area, which excessive rainfall had caused to be in- accessible by car or truck for about four months. The only equipment at the well site consisted of an ordinary steel wire line that had been carried there to measure the depth of the bridge. Since a pulling unit could not be moved to the well site, and as the pressure on the casing was 2100 lb. per sq. in., it became apparent that the only way out of the predicament was to make a perforating tool that could be lowered into the tubing on a measuring line and operated under Pressure. Thus, the first wire-line tubing perforator was designed and built as an expedient, and was not used extensively until it had been redesigned to meet more frequent and increasingly urgent needs. Until recently, it was necessary to pull the tubing to install jet collars or flow the when a well was to be placed On gas lift. Because most companies either maintained or had access to pulling units and crews for this work, little or no thought had been given to eliminating or even simplifying this task. When the manpower and steel shortage became so acute, however, many operators suddenly found themselves without facilities to equip their wells for gas lifting. The wireline tubing perforator already had been tried and proved successful, therefore operators immediately requested its use to punch gas-jet holes in the tubing, to eliminate the pulling and running of tubing strings. The first deficiency revealed by more general use of the perforator lay in the inability to regulate the size of the hole punched through the tubing. The size could not be controlled to any degree of

Jan 1, 1946

By W. L. Dennen, W. W. Wirth

Research looking toward the reduction of the cost of roof support by substitution of longer-life materials for wooden timber is fully justified by the fact that roof support is an important element of all production costs. Permanent or semipermanent roof support will reduce the expense of timber-maintenance crews during steady operations, but even more markedly during idle periods. The management, therefore, is faced with the important problem of timber renewals, which in times of regular operation are frequently obscured by more urgent problems of production. Increased use of timber in the Anthracite Region of Pennsylvania is caused mainly by increased percentage of coal obtained from robbing areas, which requires more timber for safety than development work, and maintenance of long haulageways through crushed ground despite the fact that less coal is transported over them. The timber reserve in the immediate vicinity of the mines has been depleted to such an extent that it is necessary to secure 70 per cent of the timber requirements from distant sources. Originally, mine timbering in this region was done by largely utilizing round props or legs with round collars. The whole cross section of the tree from which timber was cut was utilized by forming the joints between the legs and the collars with saw and adze, using plank or round saplings for lagging behind the legs and over the collars to prevent material falling between them. The Mine Inspectors' report of 1898 records an important digression from the use of round timber, when two tunnels at the Babylon colliery, near Pittston, Pa., were timbered with 12 by 12-in. square timber sets with mud sills, through quicksand for distances of 425 and 160 ft., respectively. The timbers were lagged with 3-in. plank to control sand. An early step toward the permanent type of roof support was the installation of "brick pillars or perfect arched brick rooms" instead of

Jan 1, 1940

By W. L. Dennen, W. W. Wirth

Research looking toward the reduction of the cost of roof support by substitution of longer-life materials for wooden timber is fully justified by the fact that roof support is an important element of all production costs. Permanent or semipermanent roof support will reduce the expense of timber-maintenance crews during steady operations, but even more markedly during idle periods. The management, therefore, is faced with the important problem of timber renewals, which in times of regular operation are frequently obscured by more urgent problems of production. Increased use of timber in the Anthracite Region of Pennsylvania is caused mainly by increased percentage of coal obtained from robbing areas, which requires more timber for safety than development work, and maintenance of long haulageways through crushed ground despite the fact that less coal is transported over them. The timber reserve in the immediate vicinity of the mines has been depleted to such an extent that it is necessary to secure 70 per cent of the timber requirements from distant sources. Originally, mine timbering in this region was done by largely utilizing round props or legs with round collars. The whole cross section of the tree from which timber was cut was utilized by forming the joints between the legs and the collars with saw and adze, using plank or round saplings for lagging behind the legs and over the collars to prevent material falling between them. The Mine Inspectors' report of 1898 records an important digression from the use of round timber, when two tunnels at the Babylon colliery, near Pittston, Pa., were timbered with 12 by 12-in. square timber sets with mud sills, through quicksand for distances of 425 and 160 ft., respectively. The timbers were lagged with 3-in. plank to control sand. An early step toward the permanent type of roof support was the installation of "brick pillars or perfect arched brick rooms" instead of

Jan 1, 1940

By G. V. Woody, J. D. Price

Many producers of by-product coke have spent considerable time and given considerable thought to the use of a substitute for low-volatile coal as an admixture with high-volatile coking coal for charging high-temperature by-product coke ovens. Generally speaking, there are two principal reasons for this, one being occasioned by the lack, in certain localities, of low-volatile coal delivered at a cost sufficiently low to permit its use, and another being the desirability of finding a substitute product with a delivered cost lower than the cost of the low-volatile coal. It was for the first of these reasons that the Colorado Fuel and Iron Corporation was particularly interested in this subject. This paper deals with the experimental work and the results obtained by that company in producing and using low-temperature char. Overcoming Defects in Coke from Colorado Coals Colorado coking coals are all of the high-volatile type and were all laid down during the Cretaceous period, which makes them something like 80 million or so years younger, geologically, than eastern coals. They behave, when coked alone, something like the Pittsburgh-seam coals. They make a very brittle, highly cross-fractured, fingery coke of fair shatter value but quite low in resistance to abrasion. Mixed with a low-volatile coking coal such as Poca- hontas or certain Oklahoma coals, they make a coke that is equal to virtually any of the eastern cokes. The inferior quality of Colorado coke has long been recognized, and a considerable amount of time, effort and money has been spent upon investigations of means for improving its physical properties. While it has been found that some improvement in quality of coke can be secured by the adjustment and control of such variables as pulverization, moisture content, oven temperature and bulk density of charge, and through the addition of certain inert materials such as pulverized coke breeze, pitch, high-volatile noncoking or semicoking coal, the benefits so gained have been comparatively small. There are no low or medium-volatile coking coals available within a reasonable freight-cost distance. Therefore a substitute for low-vol-atile coal was developed through low-tem-perature carbonization—or, more correctly speaking, through the partial devolatiliza-tion—of high-volatile coals. The blending of this lower volatile char with the high-volatile coking coal distinctly improves the quality of coke made from Colorado coal. There is nothing especially new about this idea. In 1908 a Japanese patent was taken out by Kotaro Shimomura, whose claim was: The method of making a nonfingery coke out of bituminous coals, without using natural coals of low-volatile matter; according to which a certain coal is heated at a temperature between about 300°C. and about 600°C. so as to leave about 15 to 25 per cent volatile matter in the coal; this coal is mixed with the

Jan 1, 1944

By J. D. Price, G. V. Woody

Many producers of by-product coke have spent considerable time and given considerable thought to the use of a substitute for low-volatile coal as an admixture with high-volatile coking coal for charging high-temperature by-product coke ovens. Generally speaking, there are two principal reasons for this, one being occasioned by the lack, in certain localities, of low-volatile coal delivered at a cost sufficiently low to permit its use, and another being the desirability of finding a substitute product with a delivered cost lower than the cost of the low-volatile coal. It was for the first of these reasons that the Colorado Fuel and Iron Corporation was particularly interested in this subject. This paper deals with the experimental work and the results obtained by that company in producing and using low-temperature char. Overcoming Defects in Coke from Colorado Coals Colorado coking coals are all of the high-volatile type and were all laid down during the Cretaceous period, which makes them something like 80 million or so years younger, geologically, than eastern coals. They behave, when coked alone, something like the Pittsburgh-seam coals. They make a very brittle, highly cross-fractured, fingery coke of fair shatter value but quite low in resistance to abrasion. Mixed with a low-volatile coking coal such as Poca- hontas or certain Oklahoma coals, they make a coke that is equal to virtually any of the eastern cokes. The inferior quality of Colorado coke has long been recognized, and a considerable amount of time, effort and money has been spent upon investigations of means for improving its physical properties. While it has been found that some improvement in quality of coke can be secured by the adjustment and control of such variables as pulverization, moisture content, oven temperature and bulk density of charge, and through the addition of certain inert materials such as pulverized coke breeze, pitch, high-volatile noncoking or semicoking coal, the benefits so gained have been comparatively small. There are no low or medium-volatile coking coals available within a reasonable freight-cost distance. Therefore a substitute for low-vol-atile coal was developed through low-tem-perature carbonization—or, more correctly speaking, through the partial devolatiliza-tion—of high-volatile coals. The blending of this lower volatile char with the high-volatile coking coal distinctly improves the quality of coke made from Colorado coal. There is nothing especially new about this idea. In 1908 a Japanese patent was taken out by Kotaro Shimomura, whose claim was: The method of making a nonfingery coke out of bituminous coals, without using natural coals of low-volatile matter; according to which a certain coal is heated at a temperature between about 300°C. and about 600°C. so as to leave about 15 to 25 per cent volatile matter in the coal; this coal is mixed with the

Jan 1, 1944