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By Francis H. Brownell

During the 1920's lead consumption in the United States reached the highest average total ever known. For the ten-year period 1921-'30, it was slightly over 600,000 tons per year, or say 50,000 tons per month, and the price averaged 6.81 per lb. But the I930's witnessed a severe drop in the consumption of lead is in other business activities. The average U.S. consumption for the ten-year period 1930-'40 was slightly less than 380,000 tons per year, or under 32,000 per month, with the average price dropping to 1.191c. per lb. The outlook in early 1939 was for a continuation of this average consumption and price a demand of 35,000 to 40,000 tons per month, and a price level of 4 1/2 to 5c. in the United States.

Jan 1, 1941

J. E. Stead, Middlesborough, England (communication to the author): Prof. Howe's valuable paper on cast-iron brings forward most prominently the correct explanation of the part played by combined carbon in pearlite and cementite, in determining the strength and hardness of cast-iron. On a previous occasioil I have shown that castings made by melting a white Cleveland iron and glazed iron, one containing 1.5 and the other from 4 to 5 per cent. of silicon, and each about 3 per cent. of carbon, were stronger than those made of ordinary foundry-iron; the difference in the final castings being a differ-

Jan 1, 1902

By J. J. Jakosky

The strategic importance of the metallic minerals in our industrial economy, and the declining rates of discovery have focused attention on means of exploration for new mineral deposits. A consideration of exploration techniques leads to an attempt to evaluate the effectiveness of geo- physics as a tool for mining exploration. One means of evaluation will be to compare the use of geophysics in petroleum exploration with its possible uses in mining.

Jan 1, 1949

By W. S. Ayres

BACK in the early nineties the old Dickerson iron mine in Morris county, N. J., was operated by a vertical shaft 850 ft. deep and by a continuing slope for more than 1000 ft. more 011 an incline of 65", together making the vertical depth about 1800 ft. I was then the general superintendent there. This mine, named for a former governor of New Jersey, had been worked more or less continuously from long before the American Revolution and up to this particular time. The pumping equipment was of the old-time Cornish type, with its long pump-rods running down the vertical shaft and the slope to the sump at its bottom. It was operated by a large flywheel engine in the engine room and all angles were turned by the usual bobs. Saturday was the day fixed for lowering the "suction" into the deepened sump at the bottom of the advancing slope. The mine foreman had gone down with the morning shift to superintend this very vital and particular work, which consisted not only of lowering the "suction" into the sump immediately after the pump had been stopped, but of securing it to the rock and putting in the added sections of column-pipe and of tightening up the numerous bolts at their joints, all before the water rose to the point of working. At an appointed time during the forenoon I had agreed to go down into the mine and join the mine foreman in consultation over any difficulties that might have arisen. At the time agreed I went down by the cage to the bottom of the vertical 850-ft. shaft, and then by ladders down the slope for over 1000 ft. more.

Jan 1, 1930

By E. Marburg

Most ingots complete solidification vertically rather than transversely. This conclusion is based on complete solidification patterns of big-end-up and big-end-down ingots developed from dumped and split ingots. New mechanisms for segregation in ingots are proposed. Internal soundness in ingots is found to depend upon adequate width of vertical core. A LTHOUGH it has long been recognized that the A internal soundness of ingots is principally been recognizedthatthedependent on the process of solidification, knowledge of this process is still only fragmentary. The mechanisms causing the several types of segregation in ingots, which mechanisms are necessarily related to the solidification process, are not well understood. In absence of a better conception of the solidification process, it seems hardly surprising that mold design varies widely. Guiding principles for mold design are needed. At stake in the improvement of ingot quality are not only improved properties of steel but also appreciably higher yields of sound steel, which would considerably decrease manufacturing costs. In the present study, following a general description of the several types of segregation in ingots, Fig. 1, complete solidification patterns of a big-endup and a big-end-down ingot, including the zones of accelerated solidification, have been reconstructed. In both ingots, a core of vertical solidification extends from the base cone to the hot-top junction. Based on the finding that ingots complete solidification vertically rather than transversely, as has been previously assumed, new mechanisms for segregation in ingots are proposed. Internal soundness in ingots is found to depend upon the width of the vertical core, which in turn depends principally upon the width to height (w/h) ratio of the ingot. Solidification patterns of ingots are of three general types: 1—those in which vertical solidification does not reach the top, 2—those in which vertical solidification just reaches the top of the ingot, and 3—those in which vertical solidification reaches the top some time before transverse solidification would reach the middle of the ingot, so that a vertical core of definite width at the top of the ingot is developed. Axial defects vary characteristically with the solidification pattern. Examples of ingots of each type are presented. Dumped ingot data reported by Nelson' have been used in developing families of curves of transverse and vertical solidification, and in deriving the effect of the w/h ratio upon the solidification pattern. Photographs of many ingots split at Homestead and at Duquesne Works, United States Steel CO., as well as those published by the British Iron and Steel Institute,' have been studied and analyzed. In the interest of brevity, only typical ingots of each type or classification from the above sources have been reproduced. Segregation in Ingots Segregation in ingots falls into three principal classifications: 1—lamellar segregation, as revealed in sulphur prints (Figs. 2 and 3); 2—zone segregation, or broad variations in composition; and 3— interdendritic, or microsegregation. The last class, of minor importance, is not considered here. When liquid metal cools, according to the theory of differential or selective solidification,2 metal of relatively high purity selectively solidifies first. Liquid segregates (principally carbon, phosphorus,

Jan 1, 1954

By R. H. Edsal, G. Horvay

The transient one-dimensional heat-conduction equation is solved for two semi-infinite media, at different initial temperatures, brought into (poor) thermal contact. It is shown that the two interface temperatures gradually approach the well-known, instantaneously assumed, common interface temperature of the case of zero contact resistance. The present analysis, with slight modifications, may be used in fair approximation also for the class of problems involving a change of phase. One particular application of the boundary value problem solved in this paper concerns the determination of the temerature distribution in metal castings and molds.P This problem has been treated extensively by analytical methods (see e.g., the literature listed in Refs. 1 to 4) by electrical analogs (see e.g., Refs. 11 to 14) and also by experimental methods (see the literature listed in Refs. 4, 5), but prior to the work of Pellini and Ruddle the experimental results were rather unreliable. Immediate motivation for the work described in this paper was to better understand the results of Pellini,' which are typified by the curves of Fig. 1. Pellini cast 20-in. high, 7-in. sq steel ingots into cast-iron molds of various thicknesses. He measured the temperatures at mid-height, at a number of stations in the casting and the mold, and obtained the cooling curves shown in Fig. 1. The most conspicuous thing about Fig. 1 is the large temperature discontinuity at the interface between casting and mold, due presumably to the shrinking away of the casting from the wall and the attendant creation of an airgap, as the casting cools. Such a contact resistance slows down the anticipated freezing rate; an analytical prediction of this is of much interest in foundry practice. The determination of the effect of contact resistance in the presence of a change of phase will be dealt with, by an approximate method, in a separate paper.' In the present paper the much simpler problem is considered in which there is contact resistance but no change of phase. This problem frequently arises in the analysis of aircraft structures.+ It can initial temperature, and may be regarded as semi-infinite. We suppose the thermal properties in the two media to be time, temperature, and space independent; there are no sources or sinks within the media. In Fig. 2(a) we illustrate, schematically, the case of no contact resistance. The semi-infinite media "0" and "2:' initially at temperatures 8 (- m) and 8(+ -), respectively, are brought into contact at time t =0. A common interface temperature 8,i = is instantaneously established, and thereafter remains constant. Temperature curves are drawn for three instants of time. When there is contact resistance between the two media, the temperature equalization occurs as sketched in Fig. 2(b). Fig. 2(c) illustrates a temperature curve, using the dimension-less notation Barber-Weiner-Boley6 have stated the equations [23a, b] given below, which govern the heat transfer in the two media, and solved them for a rather complicated special case. In their example both media "O" and "2" are finite, are insulated at their far ends, and there is steady heat input into medium 2. In Eq. [27] we give the general solution of the most important special case, where the two media are semi-infinite and there are no sources or sinks. In this case the results may be stated in simple closed form. In Fig. 3, to be discussed in the next section, we illustrate the variation of the interface temperature when steel at 2760" is brought into contact with iron at 100". This example, if we disregard the effect of the heat of fusion, is comparable to Pellini's experimental results, Fig. 1. (Unfortunately, however, experimental determination of the interface temperatures was difficult to carry out, and hence Fig. 1 is not very accurate near the interface.) In Figs. 4 and 5 of the following section, we similarly compare Pellini's sandcasting tests with analytical results for the case where steel at 2760" is brought into contact with sand at 100". It will be pointed out that, insofar as the interface temperatures are concerned, heat of fusion has a minor effect, and so the present approximation, with small modifications, may be

Jan 1, 1961

By V. H. Wilhelm

The year 1941 in the California oil industry was marked by an increased market demand, drilling activity, and production of crude oil. Although seven new oil fields and two gas fields were discovered during the year, additions to reserves from these discoveries, as well as extensions and revaluations of previous discoveries, were approximately 100 million barrels, as against estimated withdrawals of 230,233,000 barrels. The year was remarkable for the very great increase in domestic demand for all products, which more than compensated for the loss in shipments to Japan, which averaged 60,041 bbl. Per day during 1940. Demand in terms of crude during 1941 was 648,967 bbl. per day as against 632,647 for the same period in 1940. This abnormal increase in demand is due to increased industrial activity, and especially increased railroad activity. Gasoline consumption for 1941 was 241,011 bbl. per day as against 217,744 in 1940. Demand for fuel oil increased from 259,806 bbl. per day in 1940 to 285,896 in 1941, and caused a withdrawal from stocks of more than 7,473,000 barrels. During 1941, total oil storage declined 9,153,000 bbl., but additions to storage of 1,754,000 bbl. of light oil and light oil products were offset by a withdrawal of 10,907,000 bbl. of heavier products. Production during the year is estimated at 230,233,000 bbl. as against 222,784,386 bbl. for 1940. TraNsportation For a short time, California was affected by lack of transportation due to the diversion of tankers. This shortage affected the movement of oil from the Sari Joaquin mated to the refineries, since a large percentage of this production is moved to the coast through pipe lines, and thence by tankers to Los Angeles and San Fran-,iSco, Return of the tanker fleet, which may be temporary, indicates that there is a possibility of ample supplies of petroleum products in the Pacific Northwest. Drilling Activity Contrary to general opinion, drilling activity increased in 1941 over the pre-vious Year, 942 wells being completed in 1941 as against 890 in 1940, an increase Of 6 per cent. This increase was due to the increased demands for fuel oil, and also to the decreased drilling costs, which made many former marginal locations economic. The main activity caused by increased demands for fuel oil was in the Mt. Poso, McKittrick, Midway and Santa Maria Valley oil fields. Dry-hole footage in 1941 was 655,354 ft. as against 583,537 ft. for 1940. Curtailment Voluntary curtailment succeeded in holding production considerably below demand, although it was above the state quota. During the year the top allotment

Jan 1, 1942

By V. H. Wilhelm

The year 1941 in the California oil industry was marked by an increased market demand, drilling activity, and production of crude oil. Although seven new oil fields and two gas fields were discovered during the year, additions to reserves from these discoveries, as well as extensions and revaluations of previous discoveries, were approximately 100 million barrels, as against estimated withdrawals of 230,233,000 barrels. The year was remarkable for the very great increase in domestic demand for all products, which more than compensated for the loss in shipments to Japan, which averaged 60,041 bbl. Per day during 1940. Demand in terms of crude during 1941 was 648,967 bbl. per day as against 632,647 for the same period in 1940. This abnormal increase in demand is due to increased industrial activity, and especially increased railroad activity. Gasoline consumption for 1941 was 241,011 bbl. per day as against 217,744 in 1940. Demand for fuel oil increased from 259,806 bbl. per day in 1940 to 285,896 in 1941, and caused a withdrawal from stocks of more than 7,473,000 barrels. During 1941, total oil storage declined 9,153,000 bbl., but additions to storage of 1,754,000 bbl. of light oil and light oil products were offset by a withdrawal of 10,907,000 bbl. of heavier products. Production during the year is estimated at 230,233,000 bbl. as against 222,784,386 bbl. for 1940. TraNsportation For a short time, California was affected by lack of transportation due to the diversion of tankers. This shortage affected the movement of oil from the Sari Joaquin mated to the refineries, since a large percentage of this production is moved to the coast through pipe lines, and thence by tankers to Los Angeles and San Fran-,iSco, Return of the tanker fleet, which may be temporary, indicates that there is a possibility of ample supplies of petroleum products in the Pacific Northwest. Drilling Activity Contrary to general opinion, drilling activity increased in 1941 over the pre-vious Year, 942 wells being completed in 1941 as against 890 in 1940, an increase Of 6 per cent. This increase was due to the increased demands for fuel oil, and also to the decreased drilling costs, which made many former marginal locations economic. The main activity caused by increased demands for fuel oil was in the Mt. Poso, McKittrick, Midway and Santa Maria Valley oil fields. Dry-hole footage in 1941 was 655,354 ft. as against 583,537 ft. for 1940. Curtailment Voluntary curtailment succeeded in holding production considerably below demand, although it was above the state quota. During the year the top allotment

Jan 1, 1942

By E. A. Elevatorski

Wollastonite, named after William H. Wollaston, an English chemist, is a calcium metasilicate, CaSiO3. It has a short history as an industrial mineral. The earliest production of wollastonite is reported to be from a deposit near Code Siding, located north of Randsburg, Calif. At this locality small tonnages of wollastonite were quarried during 1933-34 and 1938-41, and processed into mineral wool. This operation was largely experimental and virtually no United States production was again reported until the 1950s when a large deposit near Willsboro, N.Y., was developed by the Cabot Corp. A processing plant was placed on-stream in 1953, with nearly continuous production to date, and it is currently operated by Interpace Corp. Since 1958, wollastonite deposits in the Little and Big Maria Mountains of Riverside County, and in the Panamint Range of Inyo County, both in California, have operated intermittently for production of both ornamental and commercial wollastonite. During 1973, the United States was the major producing country, furnishing about 75% of the world's output. Recent production also has come from Finland, Mexico, and Kenya. Small amounts have been shipped intermittently from India, USSR, New Zealand, Republic of the Sudan, Republic of South Africa, and South-West Africa. The principal use of wollastonite is in the manufacture of ceramics, especially wall and floor tiles. Other uses are for paints, fillers, adhesives, reinforcing agents, plastics, fluxes, and glazes. Mineralogy Pure wollastonite, CaSiO3, has the composi¬tion of 48.3 % CaO and 51.7 % SiO,. However, it is seldom found in the pure state due to the ease with which it takes into solution the metasilicates of manganese, magnesium, iron, and strontium. Predominantly, wollastonite occurs as a contact metamorphic deposit forming between limestones and igneous rocks. Commonly associated minerals are garnet, diopside, epidote, calcite, and quartz. It has a specific gravity of 2.8 to 3.0, and hardness of 4.5 to 5 on Mobs' scale. When pure, it has a brilliant white color, but with impurities it may be grayish or brownish. Luster is vitreous to pearly. Melting point of wollastonite is about 1540° C. Wollastonite occurs in coarse-bladed masses, rarely showing good crystal form. It is usually acicular or fibrous, even in the smallest of particles. The most unique property of crushed and ground wollastonite is its cleavage. Fragments of crushed wollastonite tend to be needle-shaped, imparting a high strength, and this property is the basis for many of its uses. The fiber lengths are commonly in the ratio of 7 or 8 to 1, length to diameter. Some crystals of wollastonite fluoresce under short-wave or longwave ultraviolet light, or both; colors ranging from yellow-orange to pink-orange. Specimens may also show phosphorescence. The brightness of wollastonite is a property of considerable importance to the paint industry. Material, 99% pure, with a size of -325 mesh, has a General Electric reflectance rating of 92 to 96%. Chemically, wollastonite is inert and this property makes it useful as a filler and reinforcing agent. There are two polymorphs of calcium silicates: wollastonite, a low temperature form, and pseudowollastonite, a high temperature form. Inversion of wollastonite to pseudowollastonite occurs at about 1120° C, resulting in an increase in the coefficient of expansion and a color change. Pure white wollastonite, on inversion, may change to a cream tint, or various shades of red or brown. The color change is thought to be due to the presence of iron and strontium.

Jan 1, 1975

By Rex E. Cheek, Donald E. Menzie

The fluid mapper, a model relatively new to the petroleum industry, was used to study the effect of various mobility ratios on the areal sweepout efficiency for two typical spacing patterns. The experiments indicated the areal sweepout for the five-spot pattern varied from 51.8 per cent at a mobility ratio of 0.093 to 89.1 per cent for a ratio of 24.4. In the direct line-drive pattern, the areal sweepout varied from 58.7 per cent at a mobility ratio of 0.089 to 92.0 per cent at a ratio of 24.8. The fluid mapper may prove useful to determine quickly the effective areal sweepout for any well spacing. INTRODUCTION The effect of the mobility ratio on the areal sweepout efficiency during primary depletion of a water drive reservoir and during secondary recovery operations has recently become more widely recognized The mobility ratio, M, is defined as: _ kjp (displaced fluid) k/u (displacing fluid) where k = effective permeability u = viscosity When the displacing fluid is miscible with the displaced fluid, the permeabilities are equal and the mobility ratio may be expressed as a ratio of viscosities: u (displacing fluid) u (displaced fluid) The mathematical analysis for calculating the areal sweepout efficiency with mobility ratio other than unity is quite tedious.5,11 An experimental method by using a potentiometric model2 in a step-wise manner and in using an X-ray shadowgraph model3,12 with continuous fluid flow has been published. Several types of models have been used to study oil and gas reservoir performance. These models may be classified as physical, electrolytic, potentiometric, X-ray shadowgraph, and fluid mapper. The X-ray shadowgraph and fluid mapper are models relatively new to petroleum engineering and have not been used extensively for specific applications. The theory of the fluid mapper indicates it may be adapted to a study of areal sweepout efficiencies for various mobility ratios as well as other complex problems in petroleum engineering. The use of the model and results obtained when using displacing and displaced fluids of equal densities but different viscosities are discussed. FLUID MAPPER DEVELOPMENT H. S. Hele-ShawV eveloped a fluid mapper model based on the hydrodynamic theory. This theory is that in the steady flow of a viscous fluid between horizontal parallel plates spaced a very small distance apart, the effect of viscous shear is of such magnitude in the vertical plane that the motion in the horizontal plane is practically undisbrted streamline flow. Techniques developed by Hele-Shaw were not expanded and no additional developments in fluid mapper models were forthcoming until A. D. Moore, University of Michigan, published a series of papers starting in 1949, which describe the construction of a flexible and inexpensive model'h nd the fluid mapper technique for the solution of certain problems.' The essential components of the fluid mapper as developed by Moore are::.ln 1. A base slab. made of dental stone (calcium sulphate and water). which is shaped to represent the prototype. 2. Plate glass slightly larger than the slab and spaced

Jan 1, 1956

By J. C. Platt

I DESIRE to call the attention of the Institute to what is believed to be a new improvement in 'the construction of journal-bearings, having for its object the reduction of original cost as well as cost of renewals. In an ordinary railroad car we find the space between the top of the axle and the top of the box is filled with a "brass," weighing from seven to ten pounds. Of this amount of metal a comparatively small portion is subjected to the wear which it is intended to meet. The balance is, practically, a filling material, which from habit has long been constructed of the same metal. The Defreest bearing is made of three parts, namely, a malleableiron back, a bronze bearing-piece, and between them a filling-piece of sheet lead. The bronze takes the wear of the axle, the iron fills up the space and acts as a backing to the bronze, and the lead, being soft, adapts itself to the inequalities in the surfaces of the iron and bronze castings, thus insuring a uniform bearing on all points, and making it unnecessary to bore out the iron or turn off the bronze to bring them to a perfect contact at all points. These three parts are joined together by two soft brass rivets, with counter-sunk heads, to prevent separation in handling. A groove is cast in the iron, and a corresponding rib on the bronze, to prevent the latter from turning with the axle when in place. In renewals it is ordinarily necessary simply to drive out the rivets and renew the bronze and lead. The iron part is not subjected to much wear and should last for years. It is evident that the first cost of these journals, and also the cost of renewals, must be much less than the old form. This difference amounts, at the present price of materials, to $9.60 for an eight¬wheel car, in first cost, and $4.72 for renewals. These bearings have been in use, and found to do what is claimed for them.

Jan 1, 1880

By Donald E. Grimes

In conjunction with Inland Steel&apos;s development of lead-bearing steels possessing improved machin-ability because of tellurium and/or selenium additions, it was decided to determine liquidus and solidus temperatures in the Pb-PbTe-PbSe sub-ternary system. With the exception of alloys in the PbTe-PbSe system, it is believed that no previous study of this subternary has been performed. Thermal analysis was employed in a general survey of the subternary. In addition to PbTe, PbSe, and pure lead, ten ternary compositions were selected at intervals of ten at. pct. Sixty-gram alloys were prepared by sealing an appropriate mixture of the elements in quartz crucibles with a central thermocouple-well under a vacuum of less than 10 p. All three elements were 99.999+ pct pure with only trace impurities detected by spectroscopic examination. After the alloys had been heated at least 20°C above the liquidus in a Kanthal furnace, cooling and heating curves were obtained. Two or more cooling curves were employed both for the determination of each alloy liquidus and for the solidus of those al- loys containing greater than 50 at. pct Pb. Cooling rates were 0.5° to 3.5°C per min during the 5 min immediately prior to the start or end of solidification. For those ternary alloys containing 50 at. pct Pb, the solidus was determined from heating curves. Temperatures were measured with a Pt/Pt-10 pct Rh thermocouple which was calibrated in the same apparatus against the freezing points of zinc (A. D. MacKay—99.999 pct), antimony (A. D. MacKay-99.999 pct), and copper (ASARCO—99.999+ pct) both before and after the experimentation. The only interruptions in the continuous strip-chart recording of the temperature occurred for brief periods at significant points of interest when direct readings were made with a Rubicon Type B potentiometer sensitive to * 1 µv. The average liquidus and solidus temperatures obtained in this investigation are listed in Table I together with probable errors based on the accuracy of the thermocouple calibration and the reproduci-bility of the data. No chemical analyses of the alloys were performed because the synthetic or as-charged compositions were felt to be reliable. The melting points obtained for PbTe (924.7° ± 0.7°C) and PbSe (1084.0° ± 0.6°C) compare favorably with recent findings of other investigators.&apos;-&apos; As indicated in Table I, both the liquidus and solidus temperatures increase as selenium replaces tellurium for a constant atomic percent lead. As a result, the ternary liquidus and solidus temperatures for a given percent lead lie between the corresponding binary temperatures published in the literature. It should be noted that those ternary alloys containing 50 at. pct Pb exhibit a relatively narrow liquid-plus-solid region (<80°C) when compared with alloys containing greater than 50 at. pct Pb. Alloys with 60, 70, or 80 at. pct Pb not only have a much wider liquid-plus-solid region (>500°C) but also exhibit considerably lower and approximately constant solidus temperatures which thus form a virtually isothermal solidus "plane" slightly below the melting point of pure lead (327.3°C). For these alloys

Jan 1, 1965

By Richard L. Ash, J. H. Kelley, W. H. McCracken, William Bellano, J. D. Morgan, D. R. Mitchell

Rubber-tired shuttle cars are finding increased use as gathering units in under-ground mines. As the name implies, they shuttle back and forth between the loading machine and the section transportation system. In many mines their use has in-creased the efficiency of the loading and gathering operations, resulting in increased output per man employed and decreased costs per ton. A car motivated by cable reel is shown in Fig I, and a car with battery power in Fig 2. A brief chronological account of the development of rubber-tired haulage equip-ment follows: 1936. J. H. Fletcher1 installed his first unit for the Blue Bird Coal Co., Carrier Mills, Illinois. This unit consisted of a battery-powered industrial tractor and a trailer with drop-bottom doors. The coal was transported for short distances to a hopper for discharge into mine cars. 1938. A battery-powered self-contained shut-tle car with rubber-tired wheels was built by the Joy Manufacturing Co. Two units were installed for the Katherine Coal Co., Lumberport, West Virginia. The shuttle car consisted of a materials-receiving body with a conveyor in the bottom to move the coal forward during loading and to unload the coal at the discharge station. 1938. A cable-powered shuttle car with four-wheel drive and four-wheel steer was developed by A. L. Lee. Special wheels mounted on king pins on the car permitted all four wheels to be steered. The cable reel was driven by a torque motor to give the cable proper tension during the payout and uniform tension when rewound on the reel. 1940. A Joy shuttle car equipped with trolley poles and a cable reel was developed to operate on a double trolley-wire system.2 This unit was installed at a potash mine of the International Minerals and Chemicals Corporation at Carlsbad, New Mexico. It is believed to have been the first installation of its kind, and the first of shuttle cars for handling material other than coal. 1941. Truck haulage3 was introduced in the Tri State District by the Eagle-Picher Mining and Smelting Company. Storage battery electric trucks were rebuilt to handle a bottom-dump trailer. 1941—Joy shuttle cars were installed in a mine of the United States Gypsum Company, Oakfield, New York. 1943—Joy shuttle cars were installed in several bauxite mines.4,5 1945—Joy shuttle cars installed in a lime-stone mine. Because of the nature of bituminous coal beds trackless equipment has had its greatest application in bituminous coal mining. Usually a shuttle car is filled by a continuous type of loader. In Fig 3 is shown a continuous machine loading coal into a battery-powered shuttle car, 48-in. coal. However, intermittent types of load-

Jan 1, 1949

By Herbert Dlaska

The BBU - rotary hearth treats lead concentrates and battery scrap by the roast-reaction process. It corresponds in principle to the long-known Newnam hearth, however its hearth-basin is not straight but curved to a closed ring. In operation this annular hearth is filled with liquid lead and rotates around a central blast-box. The charge, heated to a glowing-red, floats on top of the lead bath, into which air is blown from the blast-box through a horizontal slot-type tuyere. Ore pellets and brown coal are continuously charged onto the reacting mass from two storage bins. Lead is set free by the roasting reactions and trickles through the charge into the lead bath from where it is tapped from time to time. The reacting mass is continuously stirred by a mechanical agitator and backed, by a mechanical shovel, against the water-jacketed wall of the blast-box. The gangue of the charge forms lumps of scorified character, the so-called hearth slag or grey slag, which are discharged from the hearth. The waste gases are collected in a hood and conducted to a baghouse from where the fumes and dust are automatically transported to the pelletizing installation and are recycled with new material. The daily output of lead bullion depends mainly on the lead content of the charge. With lead concentrates containing 74% lead, about 24 tons of lead bullion per day are produced on the hearth at a direct lead recovery of about 89 per cent. Approximately 10 per cent of the lead content of the new material passes into the hearth slag from where it can be recovered in a blast furnace or in a rotary furnace. For small lead smelters the BBU-process represents the most economical way of melting high-grade lead concentrates. The process requires a relatively small capital investment, consumes little fuel, utilizes cheap fuel and is very flexible. Further, of great importance, is the fact that battery scrap can be treated by the BBU-process with very good results.

Jan 1, 1970

By C. R. Simcoe, T. J. Koppenaal

The effect of direct and alternating currents on the quench aging behavior in an Al-4 pct Cu alloy has been investigated by use of resistivity measurements. The reaction rate increases with direct current density in the investigated range of 1000 to 3000 amps per sq cm. Alternating current of a specific frequency is observed to decrease the reaction rate by a factor of about two. ErDMANN-JESNITZER et al.,1,2 investigated the effect of direct and alternating current on the quench and strain aging behavior of low-carbon iron. In both cases they observed that direct current accelerates the aging reaction and that an alternating current can completely inhibit the aging process. The purpose of the present research was to investigate these phenomena in the quench aging behavior of an Al-4 pct Cu alloy and to determine the correlation, if any, between the increase in the observed reaction rate and possible heating effects accompanying the aging with direct current. EXPERIMENTAL PROCEDURE The aluminum-base alloy used in this investigation contained 3.98 wt pct Cu (1.72 at. pct) with impurities of 0.003 pct Si, 0.002 pct Fe, and 0.001 pct Mg. The alloy was rolled into a ribbon about 0.36 mm thick and 3.7 mm wide. The ribbon was split end from end with the ends being used as electrical contacts and the central unsplit section, about 5.3 cm in length, serving as the specimen. Solution treatment was accomplished by quenching from a salt bath at 520° ± 2°C into water at 25° ±0.5°C; the specimen was immediately transferred to a liquid nitrogen bath. All aging was done at 75° ± 0.2°C in a rapidly stirred ethylene glycol bath. Resistivity measurements were made by the double potentio-metric method employing a standard resistor; for purposes of convenience, the resistance measurements were made at 77°K. The transfer of the specimen from the aging bath to a liquid nitrogen dewar was accomplished in less than 1 sec. The aging kinteics were studied with the specimen being aged under the influence of direct current, alternating current, and without any type of current. The amount of heating caused by direct currents was investigated by soldering a thermocouple on the specimen surface and measuring the temperature change after applying various current densities. The temperature was observed to increase (from 75°C, the aging temperature) about 0.8°, 3.0°, and 8.5°C with direct currents of 1000, 2000, and 3000 amp per sq cm, respectively. When employing alternating current, the circuit was monitored with an oscilloscope and adjustments made to produce a normal sine-wave pattern. RESULTS Prior investigations3&apos;4 in the aging characteristics of A1-4 wt pct Cu have shown that the resistivity initially increases, reaches a maximum, and then decreases to values significantly lower than the as-quenched resistivity. This type of behavior is seen in Fig. 1 which shows the resistivity at 77°K as a function of aging time at 75°C observed in this investigation. At this aging temperature, the resistivity maximum is seen to occur in about 1 to 1-1/2 min and it further decreases to the as-quenched value in about 24 min. The behavior observed with the application of direct currents of 1000, 2000, and 3000 amp per sq cm during aging is shown in Fig. 2. With increasing current densities, (+) ?pmax decreases and the rate of the aging process increases. The time necessary to reach the as-quenched resistivity value decreases from 24 min for aging without current to about 16, 10, and 7 min for aging with 1000, 2000, and 3000 amp per sq cm direct current, respectively. Fig. 3 shows the results obtained when two changes were made during the aging with 2000 amp per sq cm

Jan 1, 1963

By John T. Galey

In southwestern Pennsylvania 151 wells1 were completed during 1938, a total of 61 less than the preceding year. Of this number 81 were gas wells and 28 oil wells, which shows a considerable decline from 1937, when 108 gas wells and 64 oil wells were completed. However, 42 dry holes were drilled during 1938, which is two more than the previous year. Shallow Development—Gas No new extensions to old pools, or new wells that would indicate any substantial reserves, mere found during the year. However, a number of commercial wells and many dry holes were drilled to the Big Injun sand in Menallen township, Fayette County. One well had an initial open flow of 6 million cu. ft. In Rich Hill township, Greene County, one well producing, from the Big Injun sand, 2 million cu. ft. was brought in. Several other gas wells were completed in Shaler township, Alleghany County and Center township, Greene County, both of which had initial open flows of 1 million cu. ft. from the 30-ft. sand. Another well, in Aleppo township, Greene County, had an equal volume from the Gordon Stray sand. Oil Development has proceeded at a retarded rate because of the low price of Pennsylvania-grade crude. A total initial of only 205 bbl., an average of 7.3 bbl. per well, was developed. This is 1785 bbl. less than during 1937 and no new repressuring operations have been contemplated to prevent the declining production. The average price received for oil was $1.56 per barrel, with a high of $1.88 and a low of $1.34. This oil costs $1.94 per barrel2 to produce. The average price paid for Bradford

Jan 1, 1939

By John T. Galey

In southwestern Pennsylvania 151 wells1 were completed during 1938, a total of 61 less than the preceding year. Of this number 81 were gas wells and 28 oil wells, which shows a considerable decline from 1937, when 108 gas wells and 64 oil wells were completed. However, 42 dry holes were drilled during 1938, which is two more than the previous year. Shallow Development—Gas No new extensions to old pools, or new wells that would indicate any substantial reserves, mere found during the year. However, a number of commercial wells and many dry holes were drilled to the Big Injun sand in Menallen township, Fayette County. One well had an initial open flow of 6 million cu. ft. In Rich Hill township, Greene County, one well producing, from the Big Injun sand, 2 million cu. ft. was brought in. Several other gas wells were completed in Shaler township, Alleghany County and Center township, Greene County, both of which had initial open flows of 1 million cu. ft. from the 30-ft. sand. Another well, in Aleppo township, Greene County, had an equal volume from the Gordon Stray sand. Oil Development has proceeded at a retarded rate because of the low price of Pennsylvania-grade crude. A total initial of only 205 bbl., an average of 7.3 bbl. per well, was developed. This is 1785 bbl. less than during 1937 and no new repressuring operations have been contemplated to prevent the declining production. The average price received for oil was $1.56 per barrel, with a high of $1.88 and a low of $1.34. This oil costs $1.94 per barrel2 to produce. The average price paid for Bradford

Jan 1, 1939

By Douglas J. Robinson

A pilot scale process has been developed to separate mercury, tin, silver, and copper from dental amalgam scrap. Laboratory research led to a process which was operated in 55 gallon drum sized reactors to treat 2000 Tr oz charges of scrap per day. This paper discusses the development work, presents a flowsheet and gives an indication of the equipment necessary to carry out the process on a commercial scale.

Jan 1, 1984

By B. H. Kear, S. M. Copley

Stress-stvain curves are presented for Ni3Al (y&apos;) cvystals in several ovientations, deformed in tension and compression at constant displacement rate, at temperatures from 70° to 2000°F. Both the yield stress and wovk havdening increase with temperature, with the magnilude of the effect dependent on ovientation. The yield stress maximum occurs at 1500°F in [001], at 1400°F in [011], and at 1200°F in [111]. The suppression of the yield stress peak in [011] and [111] orientatiorzs is due to the onset of cube slip, rather than octahedval slip, a1 elerated temperatures. The temperature and orientalion dependence of work hardening in nominal single slip orientations corvelates with changes in the CRSS ratio for octahedral slip and cube slip, in agreement with a model for work hardening based on pinning of screw dislocalions by cross slip from an octahedral plane into a cube plane. It is concluded that the unique plastic properties of y&apos; have a decisive influence on both ductility and strength characleristics of y +y&apos; nickel-base superalloys. It has long been recognized that the strength of y + y&apos; nickel-base superalloys depends on the precipitation of the y&apos; phase [basically Ni3(Al,Ti)]. This paper presents new data on the strength characteristics of single crystals of simple y&apos; (Ni3Al), and forms the first step in a systematic program aimed at elucidating the mechanisms of hardening in the complex commercial alloys. 1) EXPERIMENTAL PROCEDURE Single crystals of off-stoichiometric NiA1 were grown from the melt under vacuum by a modified Bridgman method. The melt was poured into a preheated alumina mold and crystal growth was promoted from one end by gradient cooling. The crystals were homogenized by annealing in hydrogen at 2400° F for 72 hr followed by furnace cooling. Chemical analysis of samples taken from several crystals gave an average composition of 88.2 wt pct Ni. Spectrographic analysis gave as the principal impurities in weight percent— Si (0.02), Mg (0.01), Fe (0.02), Ti (0.002), Cu (0.008), and Co (0.03). Tensile specimens with specifications as in Fig. 1 were prepared by a series of operations involving electrical discharge machining, precision grinding, and electropolishing. Compression specimens with dimensions 1/4 by 1/4 by -3/4 in. were prepared in a similar manner, except for the initial shaping operation using a precision cut-off wheel/two-circle goniometer unit to give selected crystal orientations. Specimens were deformed in a Baldwin-Wiedemann testing machine with furnace attachment, using a strain rate of 5 x 10-4 sec-1. The strain measuring device consisted of extension arms attached to the tensile grips (or compression plattens) at one end and leading out of the furnace to an LVDT at the other. Temperature was controlled by a thermocouple placed in contact with the specimen. According to the known phase diagram for the Ni/A1 system,&apos; when an alloy of the specified composition is cooled from the melt, primary y (nickel solid solution) dendrites grow at the expense of the liquid phase, which becomes enriched in aluminum. At the eutectic composition the remaining liquid freezes as a two-phase mixture of y + y&apos; (Ni3Al). Upon further cooling, a solid state transformation occurs, involving the precipitation of y&apos; in the primary dendrites, and the complete transformation of the eutectic mixture to massive y&apos;. The as-cast structure consists, therefore, of y + y&apos; dendrites with interdendritic regions of massive y&apos;, i.e., transformed eutectic, Fig. 2. 2) DISCUSSION OF RESULTS 2.1) Stress-Strain Curves. Fig. 3 shows tensile stress-strain curves for crystals in orientations close to [001] deformed at temperatures from 70° to 2000°F. Both the yield stress and total elongation are strongly temperature-dependent. At 70°F, easy glide is absent, and the work hardening coefficient BIT - G/300. At T > 1500°F, the negative slope of the stress-strain curves is due to pronounced necking in the crystals. The yield stress maximum at 1500° F corresponds with a minimum in the ductility, Fig. 4. The extensive duc-

Jan 1, 1968

By Ernest A. Hersam

The rate of output of a rock crusher is based upon a certain space relation, the calculation requiring that the size and position of the jaws, the principle of motion, and the speed of the machine be known. The result is a calculated maximum output. The purpose of this paper is to develop a method of calculating this maximum output, to judge the general applicability or utility of such a calculation, and, so far as possible, to lecord calculated values as a basis for the comparison of actual results, or for estimating the capacity of a new crusher or of a standard crusher working under new conditions. A method for calculating the capacity of crushing rolls, which has been in common use for a long time, is well presented by R. H. Richards.&apos; The output is conceived as a ribbon of rock, of which the breadth, thickness and length are governed respectively by the width of the rolls, the space between them, and their peripheral velocity. The weight of the rock thus crushed in a given time can be calculated from its specific gravity, after applying a factor representing the percentage of voids in the hypothetical ribbon. The calculation of crusher capacity is made in a somewhat similar manner. While the action of rolls is simple, with few irregularities in operating conditions, in rock crushers the material advances intermittently, usually under the force of gravity alone, and is subjected to a variety of variable conditions. The effect of these variable influences upon the calculation of capacity is now to be shown. In this paper, capacity will be discussed quite apart from any consideration of mechanical efficiency; that is, results will be stated not in terms of output per horsepower, but of output for a given machine when operated at a known speed, constructed and adjusted to receive material of a known size, and to yield a product having a definite maximum coarseness.

Jan 1, 1923