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By N. S. Keith

It seems proper, before describing the plant which has been erected in Rome, N. Y., for the purpose of demonstrating the practicability of my process of refining and desilverizing lead by electrolysis, to state in a few words the principles that govern the process. They are well known to those who have studied electrical science, and to the practical electro-platers of the country, and are briefly these: If we take a plate, or other form, of metal (impure lead in this case), and immerse it in a bath consisting of a solution of the main metal (that which contains the impurities), and also immerse another plate, which shall be a conductor of electricity, in the bath, but separated from the first by the solution, and connect the former plate with the positive pole of the source of electricity, and the other plate with the negative pole, an action will go on in this bath which is called electrolysis. There is first a decomposition of the solution constituting the bath ; then a solution of the metal at the positive pole (called the anode), and a deposition upon the other plate connected with the negative pole. which plate is technically called the cathode. If the bath is properly constituted, and the current of electricity which is passed through the bath is of the proper strength and electro-motive force, the dissolution of the anode and the deposition of the metal upon the cathode will be exactly equivalent. The analysis and synthesis are opposite and equal. If, on the other hand, this solution (called an electrolyte) be not properly constituted, decomposition will go on, but there will be these effects: a superoxidation at the anode and a liberation of free hydrogen at the cathode, which free hydrogen escapes finally in bubbles through the liquid to the surface, and into the atmosphere. In the electrolytic treatment of metals simply for their purification and recovery, it is

Jan 1, 1885

By C. E. Shoenfelt, E. W. Krampert

The major oil discovery in 1938 for Wyoming was the General Petroleum Corporation's So. 1 Government, C.NW.SE. of sec. 21-35N-77W, on the Cole Creek structure in central Wyoming, 14 miles northeast of Casper. This well found commercial oil production in basal Cloverly sand (Lakota) at 7978 ft. and was completed on May 28, 1938, at 8019 ft., 3 ft. in Morrison shale. It had an initial produrtion of 10 bbl. of oil an hour but at the end of a 7-day test made 336 bbl. of oil in 24 hr. During 1938, the well produced a total of 23,161 bbl. of oil. It has been agitated about 10 days out of each month to provide fuel for lease and drilling operations, the balance of the time it has been shut in pending the completion of the second well on the structure. The Cole Creek oil is of intermediate base and has an A.P.I. gravity of 32.7". The record of the well contains the "tops" listed in the accompanying tabulation. Tops in General Petroleum Corporation's No. 1 Government Well Feet 2210 Top of the Mesa Verde (Teapot sandstone) 2960 Top Steele shale 4500 Shannon sand; good show of oil and gas 6740 Top Frontier sand; some oil saturation 6840 Halliburton test of Froutier did not show much oil, but at 6878 ft. the oil showing amounted to 50 barrels 6878-7051 Shale 7051-7062 Sand with some oil saturation 7062-7920 Shale (sandy phase of Thermopolis shale 7779 to 7788 ft.) 7920-7926 Sand (Muddy); oil-saturated 7926-7974 Shale 7974-7979 Hard, coarse, limy sand (Dakota); some oil saturation 7979-7997 Soft sand; high oil saturation 7997-8002 Shale with pyrites 8002-8016 Sand (Lakota) 8016-8019 Variegated Morrison shale 5600 Elevation Lance Creek Field.—Important extensions to the Lance Creek field in eastern Wyoming were made in 1938 by the completion of a number of

Jan 1, 1939

By A. S. Learoyd

The Anthracite Division, Bureau of Distribution, of the United atates Fuel Administration, came into existence about Oct. 20, 1917. There had been no definite policy determined upon and the distribution had been carried out by the producers and distributors of this fuel as under normal conditions. The domestic sizes had been shipped from the beginning of the coal year on Apr. 1 in about their usual proportions to the various sections of the anthracite consuming territory of this country, which, in a general way, extended as far west as Nebraska and Montana, and in the south along the Atlantic seaboard to Florida. With the advent of cold weather, about the middle of November, acute shortages commenced to develop all over the northeastern section of the country, due to largely increased demand by the public in general, to enormously increased population in centers where industrial war activity was concentrated, and by the needs of the war industries themselves. Commencing with the early part of December, this demand was aggravated by extreme low temperatures and heavy snow; and the production decreased for the same reasons. From that date until the change in the weather, about the latter part of February, it was simply a question of getting coal into communities as emergencies occurred, to take care of individual cases. No definite plan of distribution could be followed. The coal mined between Apr. 1 and Nov. 1 had been distributed as mined and therefore only current production was available for distribution. The Anthracite Division, during this period, consisted of a Director, two assistants, together with an office force .of seven or eight clerks and stenographers. The trying experiences of the winter of 1917-18 had, however, shown a ready willingness on the part of the anthracite operators and distributors to cooperate in every way with the United States Fuel Administration. It was realized that if a definite and comprehensive plan of distribution could be formulated to become effective Apr. 1, 1918, determined on the actual needs of each state and community, the producers

Jan 1, 1920

By Francis N. Flynn

Many excellent papers, descriptive of the milling and smelting of every kind of commercial ores, the refining of virgin metals, the casting into various shapes demanded by the trade, the rolling into shapes best suited to the factory machinery and the making of composition alloys to suit every requirement have been issued by the many technical societies dealing with non-ferrous metals. It is a wonderful collection of papers, of which the mining and metallurgical engineers may well be proud, but strange as it may seem, metallurgists in general appear to take the stand that when they have delivered suitable alloys to the foundry and rolled products to the factory their duty to write papers has ceased, at least in so far as the A. I. M. E. is concerned. Still we read in the daily papers that the mining companies are absorbing metal-manufacturing industries. The purpose of this paper is to describe the reclaiming of non-ferrous scrap metals at manufacturing plants, taking as an example the automobile industry. Collection and Disposition of Scrap Until about five years ago, much of the factory scrap, with little or no preliminary treatment, was sold to secondary-metal smelters. Of late years the factory salvage department has become an important part, of the plant in reclaiming everything of value and incidentally does much of the work formerly done by the smelters. Like most good things, it is sometimes overdone, and much work is done at the factory with inexperienced men that could be done much better by experienced skilled labor at the custom smelting plants. Employees of the salvage department collect the waste products in all departments at the source and in that way avoid much contamination. Every reasonable precaution is taken to keep the scrap clean. It is hand-sorted, cut, burned, magnetized, concentrated, separated or compressed, as the case may be, preparatory for re-use in the plant or for selling to others.

Jan 1, 1930

By H. T. Mercer

THE composition of steel and the theory of its heat treatment have been so ably discussed elsewhere that it is unnecessary to go into the subject here. The purpose of this paper is to describe briefly the method of treating drill steel at the Copper Range mines, giving some of the troubles encountered and the manner in which they were overcome or corrected. To study the matter properly, it was necessary to devise a system of records that would show the actual underground performance of the drills. To illustrate this system, the records of the Champion mine are used, as it is at this mine that most of the work along these lines has been done. Reports from each drill machine are made daily by the shop and mine, and tables compiled from these reports show the footage drilled, steel broken, drills received and sent out at the shop, drills sharpened, and bits cut off. These data show what each machine or party is doing and whether the miners' supply of drills is kept up to date. There have been times when the supply of drills has been short and time lost by the miner in looking for drills. The daily records show the number and condition of drills on hand at all times. Under the old method of sharpening, the drills were heated in a coke furnace, the proper degree of heat being judged by color. Then they were sharpened in a word drill-sharpening machine, reheated in a second coke furnace where the proper heat was again determined by color, and quenched in water. While this method was fairly successful in the hands of a careful workman and for the solid steel used in the old piston drill machine, the introduction of the faster water machine, using hollow steel, produced changes both underground and in the shop. Much more was expected of the hollow-steel and' hammer-type machine, with its improved method of rotation, but troubles due to breakage, burnt bits, uneven tempering, etc., at once began to appear.

Jan 8, 1920

By Douglas Bunting

IN THE anthracite fields of Pennsylvania, mine fires occur with more or less regularity and their existence is an ever-present hazard in coal mining. In all probability 90 per cent. of the mine fires can be ascribed directly or indirectly to the ordinary miner's open lamp. Other causes may be smoking, electrical installations, gas explosions, gas feeders, and the communication of fire to the outcrops from ash dumps, culm banks, timber and brush fires. Fires in pump rooms, engine rooms, and barns have been largely eliminated as a result of the Act of .Assembly, approved June 15, 1911, which provides that all inside buildings, including engine rooms, pump rooms, barns etc. shall be constructed of incombustible materials. Smoking of pipes, cigars, and cigarettes should be prohibited in the mines and too much care cannot be exercised in preventing fires by enforcing all rules designed for that purpose. Mine fires that involve underground fighting are invariably dangerous, and all fires, irrespective of the method pursued in extinguishing them, involve property loss and expense. Each fire generally presents a more or less original problem, dependent on the particular conditions. Generally mine fires may be divided into two classes: Those occurring in inaccessible workings and those occurring in accessible workings. The methods pursued in extinguishing or controlling mine fires are as follows: (1) direct attack, (2) smothering by sealing, (3) flushing with silt or other solids, (4) flooding with water, (5) cutting off, (6) surrounding with incombustible materials, (7) digging out by stripping from the surface. Most fires are extinguished in their incipiency by direct attack and failure to extinguish by this method is due to late discovery, lack of water, and facilities for fighting, or improper procedure in the initial attack. Should the method first pursued be unsuccessful, careful consideration should be given in determining next the method to be adopted; then the work should be carried on as rapidly as possible and under the supervision f the most competent persons. Materials and supplies should be fur-

Jan 9, 1921

By Lee M. Morris

The Pittsburgh bed, lying at the base of the Monongahela series, is probably the most famous bituminous coal bed in the world; famous not only for the product yielded in mining, but also as a key horizon in the search for oil and gas. It is the most important coal bed in northern West Virginia from the standpoint of extent, thickness and regularity. The general section is shown in Fig. 1. Roof Strata The strata that superimpose any coal bed vary more than the coal itself, and the Pittsburgh bed is an excellent example of 'this fact. Obviously, there were several changes during the period of deposition of this overlying material. Locally, sandstone occurs above and in contact with the coal. Sometimes a shale, or a clayey shale, rests on the bed and is often overlain by sandstone. Throughout the greater portion of northern West Virginia, however, the basal member of the immediate roof is a black or gray clay, which is usually slickensided. This material is called "draw-slate" by the miner. The color is due to the carbonaceous matter and the slickenside is the result of pressure, or movement, which may have come during or subsequent to its consolidation. This part of the roof requires especial consideration, because it is not self-supporting after the coal has been removed from beneath. The roof coal, 8 to 24 in. thick, is left directly below the draw-slate to support it and also to protect the clay from changes in temperature and moisture in the air, thereby preventing disintegration. The clay or draw-slate quickly changes its physical character when exposed, and falls if it is not adequately supported. Timbers alone are not effective in holding up this material, because it softens, crumbles and falls around the supports. Timbers hold up only the material that is directly over the posts and crossbars. In Monongalia County In the northeastern part of Monongalia County, between the Monongahela and Cheat Rivers, sandstone is usually found immediately above

Jan 1, 1931

By Marcel Schlumberger

The electrical methods for surface-prospecting have been well developed in the last 20 years. The method involves, in the classic form, the sending of an electrical current into the soil, by means of two electrodes A and B, and studying the potential distribution at the surface, by measuring the difference of potential between pairs of points such as M and N. The points M and N are usually placed on a line between, and equidistant from, A and B. By increasing the distance AB, the current sent into the Earth, and likewise the distribution of surface-potentials, become influenced by regions of greater and greater depth below the surface. By varying the form and dimensions of the electrode-arrangements AMNB, called a "quadripole," one may make valuable deductions concerning the nature or thickness of beds, if one knows the electrical properties of these beds. On the other hand, if the form and dimensions of the electrodes AMNB remain fixed, the depth of penetration of currents in the Earth remains, so to speak, almost constant, although it tends to increase where the subsoil is more conductive, and conversely. Therefore, if one moves the constant-dimension quadripole over all the terrain to be Investigated, one achieves approximately a horizontal exploration. This permits a study of tilted beds or faulted horizon-tal beds. When the particular problem becomes deep, of the order of 2000 meters, or more, it is ne-cessary to Increase the distance between the current-sources AB to a length such that the work 'comes very troublesome, especially if the region is wooded. At the same time, the separation the points M and N must be likewise great (for example, one km) in order to obtain differences potential which are not too small; the measurement of potential differences across MN is then difficult because of the presence of parasitic potentials, due to a flow of telluric currents in fourth, and the order of greatness of these currents may exceed the quantities to be measured.

Jan 1, 1940

By E. E. Malouf

With the continued development of low-grade porphyry copper deposits by open pit mining, substantial amounts of copper-bearing strip material have been accumulated in waste dumps adjacent to the many large mines. Since the end of World War II, the production of copper from leaching these copper-bearing wastes increased from approximately 4% of the total copper production to 10% by the early 1960's. Projected increases will probably raise this figure to 20 to 30% by the early 1970's. Furthermore, a gradual recognition of the economic feasibility of leaching mined-out areas is evident and will undoubtedly contribute additional production. Waste dumps in canyons and gulches on the periphery of open pit mines, mine stopes, caved areas, and abandoned open pits often contain substantial quantities of leachable rock ranging in concentration from 0.1 to 0.4% copper. Recent developments in the leaching of copper, mainly the recognition of bacterial oxidation of sulfide minerals combined with better under- standing of the control of the salt content of the leach solutions, both by adjusting the pH and/or by hydrolysis, are resulting in a greatly expanded recovery of copper from these hitherto uneconomic mine rejects. 11.5-1. Mechanism of Leaching. Leaching processes for the extraction of metal values from mine ore or waste may be classified for convenience as either chemical leaching or bacterial leaching. Chemical leaching is considered to be the extraction of soluble salts by metathesis in acidic, basic, or neutral water solutions. The reactions involved may be evaluated by chemical thermodynamics. Bacterial leaching, although a chemical process, is dependent on biological catalysis and this is generally a much more complex process. This justifies its separate treatment in the application to leaching. Acid ferric sulfate solutions are commonly employed in the mining industry to leach valuable metals from metal sulfide ores. The leaching mechanism is a reduction-oxidation reaction in which minerals are oxidized at the expense of ferric sulfate. Such chemical leaching is profitable when

Jan 1, 1968

By J. M. Glass, C. D. Sholtess

We at Hughes Tool Co. are extremely proud of the quality of the hardware and techniques introduced through our efforts in tunnel-machine development and of the ready acceptance of them by manufacturers and contractors throughout the world. All of us who attended the conference and who are represented in the book, we believe, anticipate an increasing need for improved methods of underground excavation. The development of such methods will permit the further exploitation of our underground resources plus providing underground space for transportation and habitation at a rate compatible with demand. We hope that our comments, derived from the application of Hughes Tool Co.'s rotary boring experience, may provide a better understanding of the boring method as a possible avenue through which the desired improvement in underground excavation may be attained. We hope you may also become aware of some of the problems Hughes, as a pioneer developer of raise, shaft, and tunnel-boring equipment, must face prior to further major undertakings in this very interesting field. Our task is to acquaint you with the present status of the Hughes Tool Co. development program as it relates specifically to tunnel-boring machines. We feel this task can best be accomplished by a brief review of the general sequence of events leading to and constituting an equipment development program and more specifically the manner in which these events have occurred to either influence or further our boring-machine development program. The development of a machine to accomplish a certain function or series of functions is usually a very long and tedious process to which any number of individuals must contribute, perhaps over a period of centuries. Of particular irony is the fact that often those who contribute most generously do not necessarily reap the greatest immediate benefit. A marketable ma- chine will, however, result from a sequence of events such as these: 1) A problem or need is defined. 2) An idea is born to eliminate the problem.

Jan 1, 1970

By V. (“Viv”) R. Forbes

[ ] INTRODUCTION "The Liberal Party believes that the State's mineral resources belong to the people of Queensland and therefore it is essential that the state, on their behalf, obtains maximum benefit from the development of those resources." (Liberal Party, 1980 "Mineral Resources Policy" p.2). "Unless sound policies are implemented.... increased production of minerals will benefit only the already wealthy and the lucky few... A resources tax is essential to ensure that above normal profits are shared by the whole community.... Labor policies on taxation must ensure an adequate return from mining developments to the Australian people." (Labor Party Policy Paper, May 1982 "National Issues relating to rapid expansion of mineral production during the eighties". p.1, 37, 47). Judging from these statements, key political parties in Australia believe that mining profits are lightly taxed and that shareholders get most of the benefits. THE REALITY The Government Share of Income statement in Table 1 attempts to measure the government share of the income generated by the "Big Five" Australian mining companies - Broken Hill Pty Ltd. (BHP), CRA Limited, Utah International, MIM Holdings Ltd., and Western Mining Corporation ("WMC"). These companies control over 70% of Australia's mining industry including all the most profitable mining operations. They dominate the mining and processing of iron and steel, aluminum, manganese, coal, oil and gas, copper, lead, zinc, silver, nickel, gold, ferro-alloys and salt in Australia. They are also major world exporters of most of these products. They are thus a representative sample of the profit-earning side of the Australian mining industry. In their two most recent financial years these five companies had income before tax of A$6,980 million. The Government share of this income was A$6,285 million or 90%. The total market capitalisation of the Big Five is about A$8,480 million. (December, 1982). Governments thus consumed the equivalent of 82% of their total value in just two years. This was taking place while the politicians drafted the above statements calling for an "adequate" share for the people.

Jan 1, 1985

By Arthur Phillips, Carl H. Samans

The study of anisotropy in metals has been greatly stimulated in recent years by the rapid development of X-ray methods for determining the crystallographic relationships of wrought and annealed materials. Prior to this time the knowledge regarding the directional properties of commercial alloys consisted almost exclusively of observations of a practical nature made during the fabrication of metal objects, supplemented by a limited number of mechanical tests on specimens cut at various angles to the direction of working. Such observations clearly indicate that the common methods of cold-working metals cause both a crystallographic and a mechanical fibering varying in character and degree according to the nature and extent of the deforming process. Even after annealing, following certain not too well known combinations of reductions and anneals, a preferred orientation may exist,, thereby constituting a residual fiber effect sufficiently pronounced to manifest directional properties. With the application of the X-ray the experimental horizon was extended chiefly because the study of anisotropic metals promised to offer direct and quantitative evidence regarding the involved mechanism of fragmentation and plastic flow. As a natural consequence the intensive studies in this direction have yielded a vast accumulation of data of ultimate potential value. Unfortunately, however, as is commonly the case in entering a virgin field of experimentation, many of the data cannot be molded into complete and coherent form because of the many unrelated conditions of the experimental projects. Again, the results of the study of single crystals have been rather naturally but at times indiscriminately applied to poly crystalline metals. Furthermore, sweeping statements have been made regarding the behavior during working and annealing of metals and alloys, entirely on the basis of similarity in lattice arrangement. There is abundant reason for believing that relatively small concentration variables, differences in magnitude and distribution of applied stresses, and the character of associated annealing treatments may in some cases greatly influence the mechanics of flow

Jan 1, 1933

By H. l. Burghoff, D. E. Lawson

The presence of tellurium in copper and, by inference, in copper alloys, has been considered seriously detrimental and has been avoided. In particular, very small amounts of tellurium have been found to produce red-shortness, although the effects on cold-working and ordinary physical and mechanical properties have not been known so definitely. References in the literature are few, but as long ago as 1881, Eglestonl reported that 0.083 per cent tellurium in fire-refined copper rendered the copper red-short and therefore worthless for hot-rolling. In hot-rolling copper cakes containing this amount of tellurium, he found that fine cracks appeared in the cakes on the first pass through the rolls, the cracks opening further in successive passes. When cold, the metal was said to be tough and malleable. A few years ago, during the course of an investigation in our laboratory on copper-base alloys, it was found that tellurium-bearing alloys could be machined much more freely than similar alloys not containing tellurium. The study was pursued further in this direction, and considerable data were obtained, which indicated that certain tellurium-bearing alloys might have properties of commercial interest. The work eventually led to patent protection,2 a wide range of tellurium-bearing copper-base alloys being covered. This article presents results obtained on the effect of tellurium on the mechanical properties of three copper-base alloys: commercial bronze (90 Cu, 10 Zn), 1.5 per cent tin bronze (98.5 Cu, 1.5 Sn), and silicon bronze (96 Cu, 3Si, 1 Zn). Several alloys were cast in each series, with tellurium content ranging from 0 up to about 1 per cent. The alloys were melted under charcoal in a clay-graphite crucible, using a high-frequency induction furnace, and were cast without undue difficulty in rod form, 15/8 in. in diameter. Charges for the zinc and tin series were made up from the following materials: cathode copper, electrolytic zinc, tin, and tellurium in slab

Jan 1, 1938

By W. F. Netezband, E. H. Crabtree

The productive area of asphalt-bearing sandstone in Missouri is near the Missouri-Kansas state line near Nevada, the county seat of Vernon County about 100 miles south of Kansas City. While production thus far has been confined to Vernon and Barton counties, there are known deposits in adjacent counties. The area is served by four railroads: the Missouri Pacific, the Kansas City Southern, the Missouri-Kansas & Texas, and the St. Louis & San Francisco. The plant of the Reliance Rock Asphalt Corporation is in Vernon County, about 5 miles west of Nevada, at Ellis, a flag station on the Missouri, Kansas & Texas Railroad. A siding has been built to the plant SO that the finished product can be loaded directly into railroad cars. The property consists of a lease of 240 acres in one block. All portions of the property not required for quarrying or processing the asphalt-bearing sandstone are used for farming by the fee owner. The entire tract is very flat so that there are no transportation difficulties from quarry to plant. Geology The commercial asphalt-bearing sandstones are all of Pennsylvanian age, the major portion of the production coming from the Cherokee formation, the basal member of the Des Moines group. The Cherokee formation includes all beds between the base of the overlying Fort Scott limestone and the Mississippian limestones below. It underlies most of the area, but in the west and northwest townships of Vernon County, and elsewhere in local outliers, the Henrietta limestone, forming mounds, escarpments and high ridges, covers the Cherokee, and is in turn covered by the Pleasanton shale. In the eastern portion of the counties, the Mississippian limestones are exposed. The thickness of the Cherokee varies according to the amount that has been removed by surface erosion. Where fully present under the Henrietta; it is approximately 375 ft. thick, but over most of the county it ranges from 100 to 200 ft. thick.

Jan 1, 1938

By Arthur Phillips

THE study of anisotropy in metals has been greatly stimulated in recent years by the rapid development of X-ray methods for determining the crystallographic relationships of wrought and annealed materials. Prior to this time the knowledge regarding the directional properties of commercial alloys consisted almost exclusively of observations of a practical nature made during the fabrication of metal objects, supplemented by a limited number of mechanical tests on specimens cut at various angles to the direction of working. Such observations clearly indicate that the common methods of cold-working metals cause both a crystallographic and a mechanical fibering varying in character and degree according to the nature and extent of the deforming process. Even after annealing, following certain not too well known combinations of reductions and anneals, a preferred orientation may exist, thereby constituting a residual fiber effect sufficiently pronounced to manifest directional properties. With the application of the X-ray the experimental horizon was extended chiefly because the study of anisotropic metals promised to offer direct and quantitative evidence regarding the involved mechanism of fragmentation and plastic flow. As a natural consequence the intensive studies in this direction have yielded a vast accumulation of data of ultimate potential value. Unfortunately, however, as is commonly the case in entering a virgin field of experimentation, many of the data cannot be molded into complete and coherent form because of the many unrelated conditions of the experimental projects. Again, the results of the study of single crystals have been rather naturally but at times indiscriminately applied to polycrystalline metals. Furthermore, sweeping statements have been made regarding the behavior during working and annealing of metals and alloys, entirely on the basis of similarity in lattice arrangement. There is abundant reason for believing that relatively small concentration variables, differences, in magnitude and distribution of applied stresses, and the character of associated annealing treatments may in some cases greatly influence the mechanics of flow and consequently largely determine the final structural characteristics of the metal.

Jan 1, 1932

By Sixten Wollmar

A RESUME. of some important points regarding the life of drill steel, which have so far been learned from investigations carried out in the SKF Hofors' mines, Sweden, by L. Nordenfelt, is given below. By examining all fatigue breakages which occurred in the test it has bees conclusively proved that when a rock drill of the self-rotating type is used all break-ages of this kind start from the surface of the hole in the steel. It has further been proved that the rough hole surfaces (i.e., the marks left by the indentations of the sand core), are the starting points for the fatigue cracks and that the corrosive action of the water has .a very detrimental influence on the life of the steel. It is now a well known fact that this corrosive action concentrates at the bottom of the indentations left by the sand. The corrosive action of water has been well described by U. R. Evans in his paper, "Some Recent Work on the Corrosion of Metals," delivered on March 31, 1926, before the Liverpool Engineering Society, which is quoted in part below: "It is well known that, under ordinary conditions, most metals do not corrode in water unless dissolved oxygen is present. The strange feature of corrosion in submerged metals, however, is that the attack does not proceed mainly over those portions of the surface which could be reached readily by oxygen; deterioration takes place at certain points which are relatively, inaccessible to oxygen. When. a metal becomes pitted by corrosion, further attack usually deepens the pits, and in many cases it could be proved that there was no free oxygen at the bottom of the pits. None of the older theories of corrosion explain the fact that, although oxygen is necessary for rapid corrosion to take place, the attack actually occurs at the very points which could not be reached directly by oxygen.

Jan 6, 1928

By Richard Bosustow, Van Dyne Howbert

The Presidio mine of The American Metal Co. is situated in the "Big Bend" region, some 45 miles over state highway south of Marfa, a station on the Southern Pacific R.R. It lies 20 miles by road north of the Mexican border, in semidesert surroundings typical of this general section of the United States and the adjoining part of Mexico. All supplies are hauled in by truck from Marfa under contract. The concentrates and precipitates produced by the mill are carried by the same trucks to Marfa, from whence they are shipped, respectively, to the El Paso and Selby plants. History The mine was discovered about the year 1880 and was soon thereafter taken over for development by some army officers stationed at Fort Davis, Texas. It was later operated by the Presidio Mining Co., which treated the ore in a small pan-amalgamation mill from 1883 until 1913, when a cyanide plant was erected which has been in continuous operation ever since. When the present company, a subsidiary of The American Metal Co., Ltd., took over the mine in April, 1926, the ore-bearing zone had been worked for about 2200 ft. to the east of I the outcrops down the dip of the formation, at which point it is at a I vertical depth of 500 ft. below the surface. Up to that time the mine had produced some 1,150,000 tons of ore averaging about 17 oz. silver. After a development campaign the company started milling again in February, 1927. Since then the production has been approximately 4700 tons per month of ore; of which the yearly average grade has varied from 19.7 to 23.2 oz. silver, $0.20 to $0.50 gold, and 2.0 to 2.5 per cent. lead. No other property in this district has ever produced tonnage of any importance.

Jan 1, 1931

By C. G. Maier

COMMERCIAL processes of lead softening directly involve the behavior on fusion of mixtures of the oxides of antimony and lead, and the vapor pressures of these materials. Practically no quantitative data have been available for the discussion of lead softening from the point of view of the fundamental metallurgy of the process. The Pacific Experiment Station -of the United States Bureau of Mines, in cooperation with the University of California, in the course of its program of study of the fundamental properties of oxides and sulfides, recently made vapor pressure measurements upon the various forms of pure antimony trioxide.1 When these measurements were considered in connection with the softening and "fuming" furnaces which are often used for lead purification, an unexpectedly anomalous condition appeared. In brief, this anomaly consisted in the fact that in certain softening furnaces, where lead bullion of approximately 1 per cent antimony content was being treated at a temperature of approximately 1300° F., no appreciable volatilization of antimony occurred, there being produced only a "skim" containing from 15 to 20 per cent Sb, 65 to 60 per cent Pb, as mixed oxides. In the "fuming furnaces," where the temperature was only about 1400° F. and where an accumulation of "skims" from the primary softener was being treated with certain other antimony-containing materials, a considerable volatilization of antimony as oxide occurred; an "impure" skim of some 60 to 65 per cent Sb and 10 per cent Pb was also produced as mixed oxides. The latter material cannot be suitably treated in hearth-type or softener furnaces. The essential chemical difference between the first and second step is the customary use of some reducing material (such as petroleum coke) in the later operation. An obvious interpretation of the effect of coke in facilitating the fuming of the antimony is the supposition that the antimony may be reduced to metal, and volatilized as such. This supposition is improbable, however, when it is realized that a slight extrapolation of the vapor-

Jan 1, 1932

By C. F. Austin, J. K. Pringle

In view of the many large differences in structure and physical properties between metals, plastics, and most rock materials, a continuing experimental petrodynamics program has been established at the U. S. Naval Ordnance Test Station. Part of this program has been to test the concepts of scabbing and corner fracturing in a typical coarse-grained rock. The results of this experimental program have shown very interesting differences between the formation of fractures in rock and the formation of fractures in other materials such as metals and plastics which are often used as models for rock behavior studies. The gross behavior of coarse-grained brittle solids subjected to impulsive loading has undergone abundant empirical investigation by mining organizations and by mineral research agencies. However, the fundamental response of coarse-grained brittle solids to impulsive loading has received little detailed study in recent years. The various organizations and agencies interested in rock-like brittle materials have broadly applied the stress wave interaction concepts of the impulsive failure of metallic samples to the behavior of granular brittle materials 1,2,3,4,5,6 Using the metallic sample approach for stress wave induced fracturing, an understanding of the fracture behavior of brittle materials which perhaps is not always appropriate has been established in the open literature. An excellent summary of the metallic sample approach is provided by ref. 7 which summarizes the general beliefs prevalent at present regarding the impulsive behavior of brittle solids: "In the blasting process, rock breakage occurs primarily from tensile slabbing, beginning at a free face and proceeding back toward the explosive charge. The tensile waves formed by the reflection of incident compressive waves from two or more free faces will collide in the rock, resulting in large localized tensile stresses. Fractures formed by the interaction of these tensile stresses begin at the apex of the free face planes and progress back into the rock as shown...."

Jan 1, 1964

By E. H. Crabtree, W. F. Netezband

The productive area of asphalt-bearing sandstone in Missouri is near the Missouri-Kansas state line near Nevada, the county seat of Vernon County about 100 miles south of Kansas City. While production thus far has been confined to Vernon and Barton counties, there are known deposits in adjacent counties. The area is served by four railroads: the Missouri Pacific, the Kansas City Southern, the Missouri-Kansas & Texas, and the St. Louis & San Francisco. The plant of the Reliance Rock Asphalt Corporation is in Vernon County, about 5 miles west of Nevada, at Ellis, a flag station on the Missouri, Kansas & Texas Railroad. A siding has been built to the plant SO that the finished product can be loaded directly into railroad cars. The property consists of a lease of 240 acres in one block. All portions of the property not required for quarrying or processing the asphalt-bearing sandstone are used for farming by the fee owner. The entire tract is very flat so that there are no transportation difficulties from quarry to plant. Geology The commercial asphalt-bearing sandstones are all of Pennsylvanian age, the major portion of the production coming from the Cherokee formation, the basal member of the Des Moines group. The Cherokee formation includes all beds between the base of the overlying Fort Scott limestone and the Mississippian limestones below. It underlies most of the area, but in the west and northwest townships of Vernon County, and elsewhere in local outliers, the Henrietta limestone, forming mounds, escarpments and high ridges, covers the Cherokee, and is in turn covered by the Pleasanton shale. In the eastern portion of the counties, the Mississippian limestones are exposed. The thickness of the Cherokee varies according to the amount that has been removed by surface erosion. Where fully present under the Henrietta; it is approximately 375 ft. thick, but over most of the county it ranges from 100 to 200 ft. thick.

Jan 1, 1938