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By Colin Fink

THE important developments within the past few years in electrochemistry, in particular in the electric furnace art, in electrometallurgy and in the methods of combatting corrosion are to be the subjects of my discussion. Fig.1 shows the rise of the electric steel furnace industry in this country and Canada. Many prophesied that the electric furnace was largely a war baby and that the sudden rise in the industry, due to the outbreak of the great war, would be fol-lowed by an equally sudden drop after the armistice. However, the curve shows that this, prophecy was not correct; the number of furnaces in operation in this country and Canada has continued to increase steadily, so that at the end of 1925 there were over 525 electric steel furnaces in successful operation. What does this mean? It has a big significance, namely that the en-tire steel industry has been revolutionized, to a certain extent, that we have been able to introduce certain alloys and steel products that we were unable to pro-duce before. On the table is. a sample of metallic chro-mium, analyzing more than 98 per cent chromium, made in the electric furnace. Before the war, the only commercial method of producing chromium was that by the Goldschmidt process. If chromium oxide is mixed with granulated aluminum, a violent reaction occurs, resulting in the production of metallic chro-mium. However, the price of chromium so made will always be above that of the raw material, which at the present time is about 27 cents a pound.. Furthermore, the chromium metal could only be turned out in small quantities, whereas in the electric furnace, large quan-tities, ton masses, can be produced today. The advent of chromium produced in the electric furnace has brought about an entire new phase in the alloy indus-try. The fuel-fired furnaces can turn out a low-carbon chromium steel that runs about 3 per cent chromium, whereas in the electric furnace, 60 per cent ferro-chromium is daily produced in large masses with almost entire elimination of carbon. It is difficult indeed to turn out ferrochrome very low in carbon. New steels are being produced today, for example the steel with which everyone has become familiar within the 'last few years, "stainless steel,". and which would have been impossible without the low-carbon ferrochrome. The elimination of most of the carbon made it possible to roll the chromium steels into thin sheets and manu-facture them into knife blades.

Jan 2, 1927

By M. B. Standing, D. L. Katz

Density data are reported on 15 saturated hydrocarbon liquids in the range of 35° to 250°F. and 1000 to 8220 lb. per sq. in. The apparent liquid densities of methane and ethane are shown to vary with the density of the system in which they are present. A method is proposed whereby the densities of liquid hydro- carbon mixtures containing both methane and ethane in solution may be computed at elevated temperature and pressures within the accuracy of usual engineering computations. A method of computing the shrinkage of crude oils based upon the gas-oil ratio, gas analysis, and crude gravity is outlined. Introduction The densities of naturally occurring liquid hydrocarbon mixtures are important in many petroleum engineering computations. Calculation of the shrinkage of a subsurface sample of crude oil as the natural gas is evolved is one example of the use of liquid-density data. Sage, Hicks, and Lacey5 have presented a method of computing the density of hydrocarbon liquid mixtures based on partial molal volumes. Katzl has indicated a method based on the principle of additive

Jan 1, 1942

By M. B. Standing, D. L. Katz

Density data are reported on 15 saturated hydrocarbon liquids in the range of 35° to 250°F. and 1000 to 8220 lb. per sq. in. The apparent liquid densities of methane and ethane are shown to vary with the density of the system in which they are present. A method is proposed whereby the densities of liquid hydro- carbon mixtures containing both methane and ethane in solution may be computed at elevated temperature and pressures within the accuracy of usual engineering computations. A method of computing the shrinkage of crude oils based upon the gas-oil ratio, gas analysis, and crude gravity is outlined. Introduction The densities of naturally occurring liquid hydrocarbon mixtures are important in many petroleum engineering computations. Calculation of the shrinkage of a subsurface sample of crude oil as the natural gas is evolved is one example of the use of liquid-density data. Sage, Hicks, and Lacey5 have presented a method of computing the density of hydrocarbon liquid mixtures based on partial molal volumes. Katzl has indicated a method based on the principle of additive

Jan 1, 1942

By Cyril Stanley Smith

The following table, which is composed of data given in the author's first paper on the thermal conductivity of copper alloys1, contains tile results which have been obtained by previous workers on the thermal conductivity of the copper-tin, the copper-phosphorus and the copper-tin-phosphorus alloys (the phosphor bronzes). a Dr. Ing. Diss., Aachen, 1909. Quoted by Schenk: Ann. der Phys. (1910) 32, 261. b Beibl. Ann. der Phys. (1906) 29, 178. c Jnl. Inst. Metals (1928) 39, 375. d Jnl. Inst. Metals (192.5) 34, 43. e Ges. Abhand. Kennt. Kohle (1919) 4, 400. Experimental Methods Since the method of obtaining measurements of the thermal conductivity was identical with that described in the author's previous paper

Jan 1, 1931

By E. R. Buchanan, R. E. Reed-Hill

A transmission electron microscope study was made of magnesium single crystals deformed in torsion using the basal pole as the forsional axis. While this type of deformation is predicted to result in the formation of hexagonal networks of screw dislocations, these networks were not observed. The basic dislocation arrangement consisted of arrays of nearly parallel and approximately equally spaced dislocations. The average dislocation density was over an order of magnitude higher than that required to account for the torsional deformation. The observed high rate of work hardening in these crystals is consistent with both their high dislocation densities and the arrangement of dislocations in pile-ups. The experimental observations are also in agreement with the assumption that dislocation sources are activated not only at the surface but at interior locations as well. In considering torsional deformation, Amelinckx and Dekeyser1 postulated that when a torque is applied to a crystal oriented with a glide plane normal to the specimen axis, deformation occurs by the following steps: 1) Nucleation of dislocation sources at or near the specimen surface in areas where the shear stress, resolved along a slip Burgers vector, is a maximum; 2) the screw orientations of the dislocations accommodating the twist move inwards towards the specimen center. If two glide directions lie on the glide plane, the geometry shown in Fig. 1 should result; 3) the screw dislocations that pile up in the central part of the specimen cross-slip to form a grid. At the same time, screws of opposite sign and most edges leave the specimen. Tinder,2 using zinc crystals twisted about the basal pole, independently reached essentially the same conclusions. He suggested a mechanism involving nucleation of ?(1120) screw dislocations at the six points of highest resolved shear stress that lie on the cross-section near the surface. Under the applied shear stress these dislocations were assumed to move inward and interact so as to form a hexagonal network of screw dislocations. Today it is often accepted that rotational slip occurs by a mechanism of the above type, but to our understanding this has never been experimentally proved. This paper reports an experimental study of rotational slip, using magnesium single crystals, that indicates that in this metal rotational slip does not conform well to this mechanism. EXPERIMENTAL PROCEDURES Mechanical Testing. Specimens with a (0002) axis were prepared from magnesium crystals of 99.95 pct purity grown by Jillson's3 modified Bridgman technique. The crystals were acid machined into cylindri-

Jan 1, 1970

IT has been discovered by skilled bell founders, more through experience than from geometrical calculation (although calculation does enter), that a certain relationship of dimensions in both large and small bells makes the tone and the weight almost certainly what is desired. This is in addition to the customary shape which is, according to the historians, perhaps that found by the first discoverers of bells. Among themselves bell founders have made a rule of these measurements and have called it the bell scale. Beginning with the small ones weighing ten pounds, it increases by degrees to a point where, as I have seen, they are able to make them even twenty-five and thirty thousand pounds. This scale is of great enlightenment if one does not have a bell already made for comparison.

Jan 1, 1942

By D. Perry, G. W. Binkley, G. K. Dumbauld, F. A. Brooks

A new cementing technique has been developed which is particularly applicable to permanent-type well completion operations. The technique makes use of the accelerating effect of calcium chloride on setting time and strength development of cement cake deposited in squeeze cementing. An unique feature is that the accelerator is applied after the unaccelera-ted cement slurry has been squeezed and the excess has been reversed from the well. Laboratory data on the accelerating effect of calcium chloride applied to the fi1ter cakes of three low-water-loss cementing compositions demorzstrate that the procedure results in relatively rapid development of strength and impermeability of the cement cake. Simulated squeeze-ceinenting tests made in the laboratory likewise corroborated the practicality of the procedure. The laboratory tests showed that a newly developed oil-emulsion cemerzting composition is more susceptible to acceleration of set than are modified cements containing high percentages of bentonite. The acceleration procedure has been used successfully in field operations. INTRODUCTION Nature of Problem In squeeze-cementing operations, a substantial amount of time is consumed in waiting on the cement to develop strength after it has been squeezed into the well. Frequently, an interval of 18 to 24 hours or longer is required for the development of strength sufficient to prevent failure of the cement during subsequent operations in the well. Reduction of this waiting-on-cement time offers appreciable savings both in time and in money. A particular type of squeeze-cementing operation to which an increasing amount of attention has been given is encountered in permanent-type well completion operations wherein perforations are to be squeezed off1. In this procedure, it is customary to pump the cement slurry down the tubing and out into the perforated section through a retractable extension pipe. Squeeze pressure is then applied, which forces the cement slurry into the perforations and causes the build up of a compact filter cake of cement within the perforations. The excess slurry remaining in the hole is then removed by reverse circulation. The extension pipe is then retracted, and, if a new interval is to be perforated, a perforating gun is run through the tubing. The newly perforated interval may then be tested by swabbing. In such operations, it has been customary to allow approximately 20 hours or so for hardening of the cement squeezed into the perforations. This time interval is usually measured from the time that the cement is reversed out of the hole to the time that subsequent swabbing is started. If the cement has not developed strength at the commencement of swabbing, the pressure differential caused by swabbing results in failure of the squeeze job. At the time that the work described in this report was initiated, particular consideration was given to the reduction of waiting-on-cement time in squeeze cementing by the permanent-type completion technique. Consequently, much of the experimental work was directed to this specific objective, though the process which was developed for acceleration of strength development has possible application in other than permanent-type completion operations. Method of Attack Although quick-setting cements

Jan 1, 1957

By C. S. Finney, John Mitchell

The growing popularity in the United States of the vertical-flue even was emphasized when in 1905 the United States Steel Corp. chose the Koppers oven as the type which best suited their requirements. Heinrich Koppers was born on November 23. 1872. at a small farm in Walbeck near Geldern on the lower Rhine. When young Koppers was eight years old, however the family moved away from the farm to the industrial city of Bochum in the Ruhr. Here Koppers attended public school and subsequently served an apprenticeship to a tinsmith before taking a job as a lathe operator with a local steel company. He had ambitions to be much more than a machinist, however, and used his week-ends and evenings to improve his theoretical background by taking courses at a vocational-training school in Bochum. After winning the highest honor the school could bestow (the silver Staats-medaille), Koppers went on to continue his education at the Rheinisch-Westfalische Hüttenschule in Duisberg. One of his teachers there, Fritz Wüst who later became a professor at the Technische Hochschule at Aachen, recognizing Koppers' unusual abilities, predicted for him a great future. In 1894 Heinrich Koppers joined the firm of Dr. C. Otto and Co. in Dahlhausen, and in 1899 while superintendent of the Mathias Stinnes mine he built his first battery of ovens for Hugo Stinnes, the German industrialist. Two years later he started his own organization, and in 1902 he made Essen his headquarters. It was to Essen that a group of engineers from the United States Steel Corp. went in 1906 with an invitation to Koppers to design and supervise the construction of four batteries of ovens at the Joliet works of the Illinois Steel Co. Each battery was to consist of 70 ovens. Arriving in the United States in 1907, Koppers established a branch of his firm in Joliet, and construction began. The first battery was fired on July 27, 1908. Rugged and simple, these ovens incorporated basic design features which were to make the Koppers oven and its future modifications the choice of a very large segment of the by-product coking industry of America. The 280 ovens at Joliet were 35 ft long, 8 ¾ ft in height, and tapered from 21 to 17 in. The total daily capacity of the four batteries was 2240 tons of coke. The ovens were of the new cross-regenerative type; that is, instead of longitudinal regenerators serving an entire battery, as in the older Koppers ovens, cross regenerators for each separate oven were employed. Fuel gas was supplied from the side of the battery through ducts in the brickwork known as gun flues, which reached to the center of the battery under the vertical heating-flues. Removable, ceramic gas-nozzles fitted at the top of each gun flue helped to insure good control over the distribution of the fuel gas, and uniform heating conditions were also promoted by regulating the air supply to, and the suction in, each heating flue. A different refractory w& used for each battery. One was built of American silica brick, one of American quartzite, and two of imported German quartzite. The installation at Joliet proved to be very successful, and in 1911, 490 additional' Koppers ovens were built for the Illinois Steel Co. at the great new steelworks at Gary, Ind. By 1912 the H. Koppers Co. had established its headquarters in Chicago and was rapidly extending its business to include construction for such iron and steel companies as the Woodward Iron Co. at Woodward, Ma. (80 ovens in 1912); the Tennessee Coal, Iron and Rail- road Co. at Fairfield, Ala. (280 ovens in 1912); the Inland Steel Co. at Indiana Harbor, Ind. (86 ovens during 1913 and 1914) ; and the Republic Iron and Steel Co. at Youngstown, Ohio (68 ovens in 1913). In 1914 a group of men in Pittsburgh bought a major shareholding in the H. Koppers Co., and moved the headquarters of the organization from Chicago to their own city. Under its new management the company was highly successful in obtaining a large share of the contracts for by-product installations built during World War I. In 1917 the remaining German interests in the company were

Jan 1, 1961

By W. T. Stuart

THE increased demand for iron ore has necessitated a re-examination of ore-bearing lands on which the presence of water previously has indicated hazardous and expensive operating conditions. In view of the importance of iron ore production to the national economy and defense, the Ground Water Branch of the U. S. Geological Survey, in cooperation with the state of Michigan, began a study of mine drainage in the Iron River district in 1945, and later extended the work to the Marquette district. The purpose of these studies was to define the principles involved in the movement of surface and ground water toward the mined areas, with the hope that the information obtained in the research would lead to the development of methods of water control and to a reduction in the total mining costs. Not only are the direct costs of drainage increasing, but also the indirect operational costs of working a wet mine are becoming a larger proportion of the total mining costs. For some wet mines the direct costs of pumping and drainage may range from 35 to 40Ø per ton of ore produced, but the indirect costs due to handling wet ore and controlling the water may be five to ten times this amount. The methods of study were formulated as the work progressed, and inasmuch as they were the first large-scale studies of their kind, they should serve as a guide for the solution of similar problems in other mining areas. The Iron River district was chosen for a pilot study because in this district the longest records of mine pumpage and water-level observations were available, including, as they do, the records for the Homer mine of the M. A. Hanna Co., where pumping from surface wells began in 1930. The results of the first investigation by the Michigan Department of Conservation have already appeared." The first section of the report on a similar study of the Marquette district, which was started in 1948, will be published this year. Methods of Study In an effort to reduce the flow of water into the mine workings in the Iron River district, about 4500 gpm was pumped from the bedrock being mined and about 9000 gpm from the glacial overburden. In the Marquette district in the vicinity of Ishpeming and Negaunee, about 5000 gprn was pumped from the bedrock and about 4000 gpm was pumped from the glacial overburden. Where the water was pumped only from the bedrock, the rate of pumping ranged from a few hundred gallons per minute in the dry mines to many hundred gallons per minute in the wet mines. In each district, pumping from the overburden was localized on a few properties where costly pumping installations had been made and the expenditures for power had been large. In each district a comprehensive ground-water investigation was made of the whole area, involving the collection and interpretation of all the available data bearing on the source and quantity of water to be controlled. Although it is not the purpose of this paper to discuss the methods of making a ground-water investigation, it should be pointed out that a drainage study follows a pattern of engineering analysis that determines the occurrence, source, movement, disposal, and quantities of water involved. The investigation in the iron-mining districts of Michigan began with the construction of a map of the buried bedrock topography. Because the ground-water reservoirs occupy the low points in the bedrock basins, this map gives information concerning their areal extent, depth, shape, and degree of interconnection. The depth to water in the drillholes and wells indicates the altitude to which the ground-water reservoirs are filled, and the logs of the material penetrated in the drillholes and wells indicate the general character of the materials filling the reservoir. The slope of the ground-water surface indicates the direction of flow through the reservoir, the water movement being from the points of higher altitude to points of lower altitude. By analysis of the rise and fall of the ground-water levels in response to additions of water through recharge and to changes in the rate of discharge through pumped wells, estimates of the total quantity of water in storage and of the rate of flow through the reservoir

Jan 1, 1952

"The richest hill on earth" had its start as a placer gold camp in 1864. The gold was quickly worked out but then silver was discovered in the copper ores in Butte Hill. After ten years as a silver camp, rich copper ore was found in 1881 and the future of Butte was assured. In the early 1960's, the Anaconda Company began the shift from underground mining at Butte to open pit mining of the enormous, low-grade copper deposit surrounding the old high-grade veins which had been worked for over eighty years. Their first primary crusher was a 66 in. by 84 in. (168 m by 2. 13 m) jaw crusher. The pit was expanded at such a rate, however, that its location became endangered. Additionally, the new Clyde Weed concentrator had been built at Butte; and in 1969 construction of a new gyratory installation was started. The primary crusher at the Clyde Weed concentrator is one of the most unusual primary crushers ever put into operation. At times, the ore from the Berkeley pit contains large amounts of timber, pipe, rails, and so forth left in the ore body from the old underground mining operations; and the crusher installation had to be designed so this tramp material could be readily removed ahead of the crusher. Ore is delivered by 100- and 150-ton trucks to two side-by-side dump pockets, each with a capacity of 400 tons. Originally, a hydraulic grapple was installed on the dividing wall between the dump pockets; but it was found that oversize boulders large enough to block the discharge opening at the bottom of each hopper were rapidly covered with other material, and the grapple was unable to reach and remove the large boulders causing the blockage. In addition, the grapple was located in a quite vulnerable position; and it sustained damage from being struck by rock dumped from the trucks. Oversize boulders are now blasted. Underneath each pocket is a vibrating grizzly feeder with the grizzly bars set at 4 in. (102 mm). These feeder-grizzlies are 84 in. (2. 13 m) wide and 32 .ft (9. 75 m) long, with grizzly sections 16 ft (4. 88 m) long. Approximately 75% of the ore passes through the grizzlies and grizzly oversize then drops onto two parallel 6 ft (1. 83 m) wide picking belts. The belts are 3 in. (76 mm) thick and rest on idlers supported by air- filled rubber shock absorbers. At the side of each picking belt is a hydraulic grapple which is used to remove timbers too large to be removed by hand. At times, four men are used to remove timber and tramp iron. Timbers are dropped onto a transverse belt conveyor which discharges into a truck stationed outside the primary crusher building,

Jan 1, 1978

By B. B. Zavoico

There were no radical changes in the petroleum situation in the Russian Soviet Union during the 1926 to 1927 operating year. The developments of the previous year were continued, but the major undertakings were far from being completed. The pipe lines from Baku to Batum and from Grozny to Touapse, and the large refineries on the Black Sea are delayed in their completion by the insufficient authorizations; until their completion the changes in the general situation will be necessarily of a halfway nature. The marketing situation was subject to much controversy during the past year and, though certain statements are quite true, the bulk of the criticism against the petroleum industry hardly deserves mention. The home market in Russia is steadily growing, with the per capita kerosene consumption already exceeding the prewar figure and fuel oil consumption obviously gaining. The foreign trade is making rapid and well-grounded success, but continues to suffer from low world quotations. There is no apparent sacrifice of home consumers in favor of export trade. The production of all Russian fields increased by 13,750,000 bbl. as compared with the 1925 to 1926 operating year, and next year's program anticipates a further increase of 9,720,000 bbl. (Table 1). The increased and improved refining facilities will make the real gain in production in the next year even larger than these figures indicate.

Jan 1, 1928

By D. S. Nilsson

Small-scale mines are today expected to provide much of the increased production of metals and coal this county demands. But in fact the category of larger mines tends to grow in number and size faster than the category of smaller mines. Larger mines show the highest productivity, the lowest injury frequency, and the lowest costs. Lower cutoff grades can be wed in larger mines. The paper describes how the production level affects the choice between different types of loading, haulage, and hoisting equipment; how the increased production level in a mine results in lower production costs per ton; and how this affects the profitability of mining deposits with various ore grades. The future trend is expected to favor larger and larger operations.

Jan 1, 1983

By T. Cantwell, N. C. Rasmussen, H. E. Hawkes

Beryl is a mineral that may be difficult to distinguish from quartz by casual field inspection. The easily recognized green color and hexagonal crystal form of coarse-grained beryl are by no means universal, even in beryl from pegmatitic deposits. If it occurred as a fine-grained accessory mineral in an igneous rock, it would almost certainly escape detection unless samples were submitted for petrographic or chemical analysis. There may be substantial deposits of some beryllium mineral, other than beryl, that has been overlooked because that mineral also closely resembles the common rock-forming minerals. A reliable and simple method of identifying beryllium minerals and determining the beryllium content of a rock would be helpful in exploration. This article describes preliminary experiments in applying nuclear reaction to the qualitative identification of beryl and to the semiquantitative determination of the beryllium content of rock samples.

Jan 9, 1959

By R. P. Carreker, R. L. Fullman, J. C. Fisher

THE existence of the phase TiAg has not been reported previously. Other investigators have denied the existence of compounds in the Ti-Ag system.13' However, phases of equi-atomic proportion have been reported by Raub, et al.' in the (similar) systems of titanium with gold and copper and zir- conium with silver. Raub's work indicated that titanium and silver are immiscible in the liquid state. No evidence of this was found although a very wide melting range exists which makes the preparation of homogeneous alloys difficult. TiAg is apparently formed by a peritectic reaction between /3

Jan 1, 1954

By G. A. Beiswenger

The application of the law of supply and demand to the sale of crude oil is generally conceded, but the motives underlying the buyer's (refiner's) demands are not always obvious to the seller (producer). In some cases this obscurity has led to the conclusion that the refiner may be unnecessarily particular when he selects one crude and rejects another. This preference, however, is very largely the reflection of the refiner's product demands and the quality of the stocks obtainable from the selected crude. The purpose of this paper is to point out critical characteristies of the major classes of refined products and to show how crudes vary in their suitability for such products. With relatively few exceptions, available processing methods and addition agents make it theoretically possible to produce any type of refined product from any crude source, although it may not be economically sound to do so. The widespread application of thermal cracking for converting higher boiling stocks into gasoline is well known. More recently cracking and refining in the presence of catalysts9 have been developed, as well as various processes for polymerizing lighter hydrocarbons into gasolines having desirable characteristics.6 For several years, selective solvents have been applied commercially to refining inferior quality kerosene, Diesel fuel and lubricating oil distillates.3 Improved methods for refining lubricating oils from crude residual4 formerly suitable only for fuel, are now in use and a number of special solvent processes are available for dewaxing lubricating oils to low pour point.5 These improved refining methods have been developed not only to meet the demand for improved product quality but also to enable the refiner to obtain quality products from crude sources that would not yield such products by the older refining methods. In many cases, the utilization of these modern refining tools necessitates an appreciable expenditure for equipment as well as added manufacturing costs, and their application therefore must be justified economically. Despite the availability of such tools, the added processing costs involved and yields obtainable may render their application entirely impractical. To illustrate this point, inspections of typical cuts from various crudes

Jan 1, 1940

By R. R. Brandenthaler

CONTROLLING -the pressure under which a well produces crude oil has advantages that are ap¬parently not entirely realized by many operators in the Mid-Continent district. The possibilities of utilizing well pressures are indicated by a series of ex-periments recently completed by the Bureau of Mines in which pressure control was successfully applied to 20 wells in, the Davenport field. The flowing period of all of .the wells was lengthened in some instances it was. more than doubled. The daily oil production from approximately one-half of the tested wells was in-creased. The amount of gas produced per barrel of oil was decreased, and this, in addition to a slower rate of decline in production, indicated that the ultimate re-covery had been increased. The successful application of pressure control to flow-ing oil wells must take into consideration the relation-ships existing between pressures in the different parts of the system which, though not equal, are nevertheless more or less interrelated. These relationships, which have such an important bearing on the results obtained by applying pressure control, are as follows: A change in rock pressure will affect the tubing pressure, casing pressure, and differential pressure, but it will not affect the trap pressure. A change in tubing pressure will affect the differential pressure and casing pressure; also, a change in casing pressure will affect the tubing pressure and differential pressure. Trap pressures are not affected by rock pressure, casing pressure, tubing pressure, or differential pressure, unless the traps are required to handle gas and oil beyond their capacity. Trap pressures will affect the differential pressure, tubing pressure, and casing pressure and any changes at the well-head, whether differential pressure, tubing pres-sure or casing pressure, will affect the pressures in the well. Any change in rock pressure results in a change in the tubing pressure, casing pressure, and differential pressure. When any sudden or unusual change in well-head pres-sures occurs (for example, an erratic tubing pressure), and when a sudden decrease in oil or gas takes place, it is al-ways advisable to note whether the trap pressure has changed. If the trap pressure has not changed, note whether the oil line from the trap to the flow-tank has become clogged, as would be evidenced by a rise in the oil level in, the trap. If the oil line is functioning properly, and if the trap pressure has not changed, the flow-line from the well to the trap should be inspected. If it is free from obstructions, then changes in the differential pressure, tubing pressure, and casing pressure must be due to changed well conditions.

Jan 4, 1927

By H. W. Krotzer

ADOPTION on a commercial scale of electrolytic deposition of metals brought with it the problem of providing an acid-proof cell or tank. Where the electrolyte contained only a dilute solution of sul-furic acid, wooden, tanks with lead linings were gen-erally adopted. There were cases, however, where a lead lining was impractical as a result of the presence of nitric acid in the electrolyte or because of the method of handling the current for deposition. purposes. Wherever lead was unsuitable for this work, asphaltic mastic was used in its place. This material, in addi-tion to possessing acid-proof qualities and being an insulator for electrical current, is also cheaper than lead. The only reason that prevented the common adoption of mastic for all work of this type was that it was still an unknown, unproved. material; while lead, although more costly, could be relied on. There are several electrolytic tank-houses equipped with acid-proof mastic linings now in operation. The first large one was the series tank-house of the Balti-more Copper Co., where the mastic used was composed of natural asphalts and a silica aggregate. These lin¬ings are now seventeen years old and still in service. The next large plant was that of the Chile Exploration Co., at Chuquicamata, Chile, ,and it is with this that this article deals. Another plant of more recent date is that of the Nichols. Copper Co., Laurel Hill, L. I., and specifications for the new electrolytic tank-house of the Union Miniere du Haut Katanga call for mastic lining. It is also being tried out on a smaller scale or for experimental purposes by many of the larger metal-lurgical companies. Thus while mastic linings were adopted originally to meet operating conditions that prohibited the use of lead, they are now in a position to compete successfully with the standard lead linings that are in general use. The Chile Exploration Co. plant, with a total area of over a million square feet, giving satisfactory ser-vice under the most adverse climatic and metallurgical conditions can be truly called the pioneer in this work. ,This article will deal with the development of the acid-proof mastic linings in Chuquicamata from the original experiments begun in 1912 up to and including the final successful installation that has now been in service for a number of years.

Jan 4, 1927

By Robert H. Richards

VERY little has been published recently on this subject in the mining journals or proceedings of societies. The attention of experts has been diverted perhaps by the demands for pan amalgamation of refractory ores. Yet free milling ores occur in many localities, and it may be interesting to have on record some data as to details of running a small test-mill, especially as details of results do not seem to be accessible to students and investigators. Küstel, in 1863, under battery amalgamation, dismisses the subject by stating that "amalgamation on copper-plated platforms, troughs, and other copper fixings" is " very imperfect, and mostly abandoned." J. Arthur Phillips says, in 1867, under placer mining : A well-amalgamated copper plate is considered as effective for

Jan 1, 1880

By William Carton, Cyril U. Cooledge

BecauSe the rich La Colorada orebody of the Cananea Consolidated Copper Co. does not outcrop at surface, after its discovery (by churn drill) and before mining was begun, a large amount of development work was done to learn the shape and extent of the ore and to provide for economic and effective mining. As these openings progressed, the actual shape of the orebody became known and with this knowledge came the realization that mining this rich and unusual deposit without loss of ore or danger to workmen presented several difficult problems. This paper will describe one of these problems; namely, the handling of an inverted cone-shaped core of barren rock, on the periphery of and below which the ore occurred. It mas clear that as the ore was mined out from around and under this inverted cone of rock, weighing about 3,000,000 tons, it would hang over the workings, held suspended only by its own tensile strength and threatening to crash into the stapes below with disastrous results to men and mine. The method of mining developed during the years 1928,1929 and 1930 anticipated and provided for the eventual collapse of this core of rock. In November 1936 the core settled down gradually on the edges of the stopes, descending a total of about 50 ft. vertically. The men in the stopes had ample warning and no lives were endangered. There were no air blasts in the mine. The core broke loose from its top support at the 500-ft. level along old fracture planes and evidently is crushed to the ninth level. Movement was of short duration; the following shift went to work in the stopes as usual. No ore was lost. Geological Structure The shape of the orebody is illustrated in Fig. 1. The geology of the Colorada orebody has been described by V. D. Perry1 and by W. G.

Jan 1, 1940

By Cyril U. Cooledge, William Carton

BecauSe the rich La Colorada orebody of the Cananea Consolidated Copper Co. does not outcrop at surface, after its discovery (by churn drill) and before mining was begun, a large amount of development work was done to learn the shape and extent of the ore and to provide for economic and effective mining. As these openings progressed, the actual shape of the orebody became known and with this knowledge came the realization that mining this rich and unusual deposit without loss of ore or danger to workmen presented several difficult problems. This paper will describe one of these problems; namely, the handling of an inverted cone-shaped core of barren rock, on the periphery of and below which the ore occurred. It mas clear that as the ore was mined out from around and under this inverted cone of rock, weighing about 3,000,000 tons, it would hang over the workings, held suspended only by its own tensile strength and threatening to crash into the stapes below with disastrous results to men and mine. The method of mining developed during the years 1928,1929 and 1930 anticipated and provided for the eventual collapse of this core of rock. In November 1936 the core settled down gradually on the edges of the stopes, descending a total of about 50 ft. vertically. The men in the stopes had ample warning and no lives were endangered. There were no air blasts in the mine. The core broke loose from its top support at the 500-ft. level along old fracture planes and evidently is crushed to the ninth level. Movement was of short duration; the following shift went to work in the stopes as usual. No ore was lost. Geological Structure The shape of the orebody is illustrated in Fig. 1. The geology of the Colorada orebody has been described by V. D. Perry1 and by W. G.

Jan 1, 1940