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M. A. SCHEIL (presented in written form).-Messrs. Franks, Binder and Brown are to be congratulated for the splendid paper that they have presented. We have not made stress-corrosion tests with the cantilever type of specimen which they describe, but it is well known that a uniform stress across a certain portion of the gage length can be obtained with such a specimen. This type of specimen would appear quite expensive to make. The writer was interested in the authors' remarks concerning the erratic results obtained from specimens with cold sheared edges. It might be of general interest to record here some results we obtained with annealed sheet N4 in. thick of type 304 stainless steel. After specimen No. 4 had been exposed 65 days without any signs of cracking we applied a strain gage and measured the stress as 25,810 psi. This value is considerably higher than we find for some of the type 347 stainless alloys and suggests that 18-8 might have a different threshold value for stress-corrosion cracking than 18-8 columbium. The test data in Table I show that strain caused by cold work or polishing has a pronounced effect in lowering the time for failure. In my paper I showed values of 8 hr. and 17 hr. to stress crack cold-rolled type 301 stainless steel stressed beyond the yield point. This steel contained 8.31

Jan 1, 1945

By George S. Rice

The increasing use of mechanization at the face of the workings in coal mining and the consequent necessity of special supports of the roof has led, in several countries, to considerable scientific investigation, including physical tests in mines as well as on specimens of roof rocks to obtain data on the behavior of the immediate roof strata and on the effect of its pressure on supports while the coal is being mined. The investigations discussed in this paper do not include studies of the ultimate effect of subsidence and movement of the roof rock over the mine excavation, upon higher strata and the surface, but are confined to the immediate underground effects in the workings. The more recent principal investigations which have been brought to the attention of the writer are as follows: Germany.—The trial of strip packing, the usual method employed in Great Britain in longwall workings, as compared with complete packing heretofore used in Germany and in France to minimize subsidence; the behavior and strength of metal props under load; the testing of the strength of coal measure rocks, in the laboratory of the Technical High School of Breslau; and an investigation, by a special commission, concerning "bumps" as a possible cause of instantaneous outbursts of gas in coal mines of Lower Silesia. France.—The cause of instantaneous outbursts of gas in the Gard mines and tests by the official French experimental organization of the "electrical resistivity" of coal as a possible means of detecting a condition preceding an instantaneous outburst. Great Britain.—The subsidence of the roof and rise of the floor preceding and during excavation of the coal, in longwall and in room-and-pillar or bord-and-pillar workings; the compression and lateral movement of the road packs in longwall back from the face; the extent of separation of the immediate roof layers from the higher strata following mining excavation;

Jan 1, 1932

By D. M. Warner, Samuel Daniels

In this paper are given the mechanical properties, determined by the Engineering Division, Air Service, U. S. A., of the 94 per cent. aluminum, 5 per cent. copper, 1 per cent. silicon alloy as 8and-cast and as heal-treated commercially to Air Service Specification No. 11,300. This particular alloy was tested both in the cast and in the heat-treated condition. Tension and tension modulus values were obtained from machined and from un-machined test specimens; while data for shear, compression, impact, torsion, and for Brine11 and Rockwell hardness were found from machined bars. Specific-gravity tests were made on sanded, un-machined specimens. The metallography of the alloy is useful as a control to heat treatment and presents some interesting peculiarities in regard to the two iron-bearing compounds. The demand for an aluminum alloy, suitable for sand castings, that may be heat treated to meet requirements of high strength, ductility, shock and corrosion resistance, and ready machineability has led to the commercial development of a proprietary material that contains from about 4 to 5 per cent. of copper, 1 per cent. of silicon, and such impurities as iron, up to a maximum of 0.75 per cent., and manganese, in quantity usually less than 0.1 per cent.' Magnesium is not generally present, for it tends to nullify the beneficial influence of the added silicon by forming magnesium silicide. The function of the silicon is to minimize casting difficulties and, structurally, to favor the precipitation of (insoluble) iron-bearing skeletons rather than the needles, which prevent full realization of tensile properties from heat treatment by stimulating intergran-ular fracture. The amount of silicon necessary to counteract the ill effect of iron is equal to or slightly more than the content of iron; the excess of silicon over this ratio, under certain conditions of heat treatment, enters with CuAl2, the principal hardening constituent, into solid solution and contributes somewhat to the strength of the alloy without appreciably impairing its ductility. The schedule of heat treatment of this alloy depends on the design (cross-sections) of the castings and on the nature of the tensile properties desired. Essentially, the process consists in heating the material at about 950" F., quenching in oil or in cold or boiling water, and artificially aging

Jan 1, 1926

By Paul Merica

ALTHOUGH nickel was discovered and isolated as early as 1750 and its valuable properties recognized, many years passed before it was used commercially for wire, sheet, rods, etc., in the pure form. This was due partly to its high cost at that time and partly to the fact that it was not possible to refine and cast nickel into ingots sufficiently malleable to be amenable to the usual forging, rolling, or drawing processes. So remarkable was this fact, and so different from the experience at that time with metals such as copper and iron, that it has left its impress on the no-menclature within the nickel industry. To this day, furnace-cast nickel produced in such a manner as to be suitable for rolling and forging is called malleable nickel to distinguish it from the ordinary pig and shot nickel of commerce. In 1878, the firm of Jos. Wharton, of Philadelphia (which later became The American Nickel Works, a constituent of The International Nickel Co.) exhibited at the Paris Exhibition specimens of rolled pure nickel strip and of drawn nickel wire. About this time, there was considerable activity in the study of the refining of nickel and several methods were described, some of which were patented, for the production of furnace-cast malleable nickel including the use of manganese (Boed-dicker,1 Selve and Lotter2), the use of potassium permanganate (Bernsdorfer Metallwarenfabrik3) and the use of phosphorus (Garnier4). By far the most efficient method was discovered by Th. Fleitmann in 1879;5 it consisted in adding to the molten nickel, just before pouring the castings, from 0.05 to 0.125 per cent. of metallic magnesium. This soon became the recognized final malleableizing treatment for furnace-cast nickel.

Jan 1, 1925

By A. F. Brock

The cut-and-fill mining methods in use in the mines of The International Nickel Company of Canada Limited, at Falconbridge Nickel Mines Limited, in the Sudbury District, and at McIntyre Porcupine Mines Limited in the Porcupine District, are typical of the general cut-and-fill practice in both the base-metal mines and the gold mines in the Province of Ontario. The following pages describe the methods in use. HORIZONTAL CUT-AND-FILL STOPING Horizontal cut-and-fill stoping, as practiced in the mines of The International Nickel Company of Canada Limited, falls into two main classifications: (I) transverse cut-and-fill stoping, where ground conditions or wide ore bodies make it necessary to establish narrow stopes and pillars across the width of the ore body; (2) longitudinal cut-and-fill stoping where ore body widths and ground conditions allow safe mining of the full width of the ore body. Transverse Cut-and-fill StopiNg General Stoping Layouts Stope and Pillar Widths.—For transverse stoping, experience has indicated that narrow stopes and pillars, 27 ft. 6 in and 22 ft., respectively, are most satisfactory. These width are multiples of 5 ft. 6 in., which is the center to center dimension of a standard square set. Thus any stope, or block of stopes, can be readily converted from cut-and-fill to square set-and-fill if ground conditions should warrant such a change. Formerly, pillars were established 16 ft. 6 in. wide, the equivalent of the width of three square sets, with the intention of extracting the pillars by mining an overhand slice one set wide and an underhand slice two sets wide. However, subsequent experience proved that a two-set overhand slice is so much more efficiently mined than a one-set slice, and 22-ft. pillars have been made standard. Chutes.—The stope chutes are established on the longitudinal center line of the stopes and are spaced at 22-ft. centers from footwall to hanging wall. The footwall chute is usually from 5 to 10 it. from the footwall of the stope. It is offset where necessary at an angle of 52° and vertical chutes are carried from the offset at 22-ft. centers. In sections of the ore body where a flat hanging wall would cut off hanging-wall chutes within a few cuts of the sill, it has proved to be more economical to use temporary chutes or slushers, or both, for these first few cuts, rather than to el permanent chutes at the hanging wall.

Jan 1, 1946

By F. W. Miller

A brief history of byproduct coking in Alabama with short general descriptions of plants and the state's production of beehive and byproduct coke. PRIOR to the Civil War, there were several small charcoal furnaces for smelting the brown limonite ore that is found, in comparatively small bodies, throughout the central and north-central portions of the state. During the Civil War, these furnaces furnished charcoal iron to the Confederate Government. No attention was paid to the large bodies of lime-bearing hematite ore that now supplies the bulk of the ore used in the various blast-furnace plants of this district until the latter part of the 19th century. Red Mountain, which is the southernmost and one of the smaller ranges of the Appalachian Chain, lying immediately south of the Birmingham and Bessemer, is the principal source of this ore. The orebody outcrops on the northern face, extends through the mountain, and underlies Shades Valley on the southern side. When it was found that these ores could be worked satisfactorily in the blast furnaces, there was a comparatively rapid growth in the blast-furnace industry in the Birmingham district. As these ores are far more refractory than the limonite ores, this blast-furnace development was accompanied by the construction of beehive ovens to carbonize the coal, in order to supply the necessary fuel. The state's production of bee-hive coke in 1880 was 60,781 tons; ten years later this had increased to 1,072,942 tons; and, in 1897 the production had reached 1,443,017 tons. In 1898, the first byproduct oven built in the state was put in operation. This plant consisted of 120 horizontal-flue Semet-Solvay ovens, three flues in height by thirty flues in length with an average width of 16 in. The plant was constructed by Semet-Solvay Co., for the Tennessee Coal, Iron & Railroad Co., and was located adjacent to the blast-furnace plant of that company at Ensley. Coal was delivered from the Pratt mines, by gravity tracks, directly into bin's of the ovens after having

Jan 9, 1924

By R. D. Carpenter, R. R. Smith, E. E. Sougstad

The Union Carbide Nuclear Co., in treating low-grade tungsten and molybdenum-copper ores at the Pine Creek mill near Bishop, Calif., employs flotation for the initial extraction of the valuable mineral constituents. These minerals consist of scheelite, molybdenite, and several of the copper sulfides including chalcopyrite, bornite, and possibly chalcocite. They occur in a gangue consisting mainly of quartz, pyroxene, and garnet, with minor amounts of calcite and fluorite. This assemblage of minerals presents an unusual grinding problem because of their diverse physical characteristics. Feed for the circuit is prepared from -6-in. ore by screening on a rod deck screen to remove the -5/8 - in. material. The+5/8-in. fraction is crushed in open circuit with a 5 1/2-ft Symons shorthead crusher operated at a closed- side setting of approximately 3/8 in. The screen undersize and the conecrusher discharge are then combined to constitute the feed to the grinding circuit. The ore is ground in 6 by 5-ft grate discharge ball mills operated in closed circuit with 54-in. spiral classifiers. The classifier overflow goes directly to the flotation section of the plant. Studies of the flotation circuits have shown that the maximum recovery of the tungsten, molybdenum, and copper minerals occurs in the particle-sue range from 100 mesh to approximately 400 mesh. Further, practice has shown that the ore minerals are effectively reduced to this size range if the total ore is ground to -48 mesh. The general objective of the grinding circuit then is to reduce the feed to -48 mesh with the production of a minimum amount of slimes. The purpose of this investigation was to ascertain how well the grinding circuit was carrying out this objective. The method used was to sample the various products in the grinding section, size these products accurately, and analyze the resulting sue distributions. SAMPLE PREPARATION AND SIZING TECHNIQUES Representative samples of the different grinding circuit products, namely, new feed to the ball mill, ball mill discharge, classifier overflow, and classifier return, were taken over a 24-hr period. The samples were then dried without being filtered to avoid loss of slimes. The percentages of solids in the different products were the following: new ball-mill feed, 95%; ball mill discharge, 82%; classifier overflow, 52%; and classifier return, 84% solids. Particle sizes were determined on each product by wet-screening an

Jan 1, 1962

By Fred C. Bond and

This paper is a continuation of two earlier papers,12 and presents new data on the grindability of various ores and other materials—the results of several years of intermittent research work on the nature of grinding and interpretation of test results. It is divided into five parts: 1. The tabulated results of several hundred grindability tests on a wide variety of ores. 2. A method of correcting screen analyses and calculating from them the surface and other properties. 3. A description of a new method of measuring the "surface energy" of an ore by pendulum impact tests. 4. Test results. 5. A general discussion of the test results and their application to grinding problems. 1. GRindability of Various Ores This part is a continuation of the paper listed as reference No. 1. The method of testing is described in detail in that paper. The sample to be tested is crushed to all through 6 mesh in rolls set at 1/16-in. opening in closed circuit with a screen. Of this sample 700 C.C. is ground dry in a laboratory ball mill under constant conditions of mill speed and ball charge in closed circuit with a screen of the desired size at 250 per cent circulating load. The mill is cylindrical, 12 by 12 in., and rotates at 70 r.p.m. It contains a charge of 285 iron balls weighing 20,125 grams and ranging from 1½ to ¾ in. in diameter. Each test is continued for a sufficient number of periods to establish equilibrium at 250 per cent circulating load, or until the composition of the circulating load is constant for successive periods. Tests are conducted at the mesh size to which the ore is to be ground in practice, and the results are expressed as the net production in grams of screen undersize per revolution of the mill. This is designated as the

Jan 1, 1939

By Samuel M. Brock

In recent years society has become increasingly concerned with maintaining and improving the quality of environment. Thus, public interest and concern with pollution problems is now high. This is reflected in recent federal and state efforts to formulate new legislation to prevent pollution and strengthen existing pollution laws. In reviewing literature pertaining to pollution problems, it is possible to distinguish many common elements. The most outstanding of these is the failure of the market to guarantee that private firms responding to price signals generated in the marketplace will make decisions leading to optimal resource use. Cases of market failure in allocating natural resources according to the wants of society frequently are due to the presence of technical externalities, or side-use effects.59 These roughly and generally can be defined as interdependencies among production and consumption units, the impacts of which are exerted other than through the market. They are, in other words, extra-market relationships. The economic unit generating external effects does not take them into account in decision-making. Thus, the tendency is for the unit to produce either more than society desires or not enough. In such cases society often has intervened in the decision-making process. This intervention frequently has taken the form of legislation to regulate production and consumption activities. Thus, a body of institutions, which acts as a constraint in decision-making processes, has materialized. These institutions are often far more influential in their effect upon resource use than are the forces of supply and demand acting in the marketplace. The problem of environmental pollution is essentially the problem of handling residuals which are the byproduct of all production and consumption activities which take place in the economy.2 These residuals are emitted into the air and water and disposed of on the land. They are interrelated, in that efforts to control emissions into the air or water can result in the production of solid wastes, which then present disposal problems. It is convenient to separate residuals by the type of pollution they cause-air, water, and land while remembering that these problems are related and that solutions may require coordinated effort.1 Residuals may be produced in both production processes and consumption. Residuals produced in production by the mineral industry, or firms utilizing its products, range from emission of sulfur dioxide by steam generating plants to radioactive mill tailings produced in the course of mining uranium.. Residuals associated with consumption are generated mainly through transportation of members of the household, space heating, and in the disposal of solid wastes, including refuse and junk autos. Residuals associated with both production and consumption receive attention in ensuing sections of this chapter.

Jan 1, 1976

By Charles Colcock Jones

In the winter of 1902, while occupying the position of mining and examining engineer for the Mountain Copper Co., Ltd., of Keswick, Cal., I had .occasion to discuss with the General Manager, among other things, the question of the enormous waste of sulphur in smelting cupriferous pyrite ore, and to cast about for means to utilize this waste or to render the fumes innocuous to vegetation. The decreasing rate of production of California farms, the consequent need of fertilizers, and the opportunity thus offered to utilize large quantities of sulphuric acid in the manufacture of superphosphates naturally brought the subject to the practical and commercial side of phosphates. I was informed that the company had made efforts to find phosphates in the West, without success. I advised as a start placing inquiries for phosphate deposits on the Pacific coast in the current mining journals. This was done, with the result that in January, 1903, from an advertisement in the Mining and Scientific Press we got track of a deposit in Rich county, Utah, through T. J. Wilson, of the Southern Pacific railroad in San Francisco. As soon as snow in the mountains would permit, in May, 1903, I undertook an examination of the property, with the result of recognizing the importance of the find, in spite of its lack of facilities for transportation at a commercial figure. On June 15, 1903, I concluded my report by saying, "This may be one of the world's deposits of phosphates." On Nov. 17, 1903, I concluded my report for the season in the following words : " I have now no hesitation in saying that I believe the Carboniferous formation so largely developed in the Wasatch mountains of Utah and the mountains of the Great Basin will prove to be one of the greatest storehouses of phosphoric acid in the world." Early History. In the summer of 1897 R. A. Pidcock, a mail carrier of Ogden, Utah, while on a prospecting trip camped on " 12 mile," a branch of

Jan 1, 1914

By Charles S. Barrett, Robert F. Mehl, Shueling Woo

WHEN one solid phase is generated from another, fixed and rational orientation relationships are observed to subsist between the parent and the new crystal. The principle has been proposed' that the relationships obtaining between the same two phases are identical whatever the type of phase change involved, or whichever of the phases may act as parent. Many types of phase changes have been studied: allotropic transformations in pure metals, precipitation from solid solutions, eutectoid decompositions, peritectic reactions, the formation of oxide layers, and others.2 Phase layers generated by diffusion of one metal into another constitute an additional type of reaction. This report provides new data on the orientation relationships occurring between , phase layers formed by diffusion, in the Cu-Zn system, § and furnishes further evidence in support of the principle. MATERIALS AND METHODS The Cu-Zn system is especially suitable for these studies since the high vapor pressure of Zn provides an opportunity readily to create one phase poorer in Zn upon a parent phase richer in Zn by removing Zn by vaporization, or to reverse this process by adding Zn from Zn vapor; e.g., the beta phase can be found as a layer upon gamma by dezincing, or gamma can be found on beta by addition of Zn from Zn vapor. Since orientation relationships are to be sought, requiring crystals large enough for orientation determinations, it is convenient to prepare single crystals or large grains of the parent phase. The samples were prepared from oxygen-free high-conductivity copper and Horse Head zinc by melting under a borax flux in a graphite crucible. Large crystals of beta brass were grown by the strain-anneal method, in plates sectioned from the cast ingots, by the following procedure. Rockwell-hardness indents were made at I cm. intervals-and with various loads, then the plates were annealed for .4 days at 700°C. in Nichrome boxes packed with beta-brass chips and graphite. Surface layers were removed by grinding and etching to a depth of about 1.0 mm., and individual grains were cut out. Crystals of alpha and gamma brass were prepared by freezing, by lowering a graphite crucible at speeds less than one inch per hour through a furnace held at a constant temperature above the melting point. Single crystals were cut out with a jeweler's saw, ground, polished and etched. Care was taken to remove cold worked layers from the finished crystals

Jan 1, 1944

By I. Fatt

Relative permeability and relative electrical resistivity curves are obtained for networks of tubes with a tube radius distribution by means of a network of resistors used as an analog model. These curves are similar to those obtained from real porous media. The effects of pore size distribution and network structure on relative permeability and resistivity are demonstrated. INTRODUCTION Study of the dynamic properties of networks of single size tubes in paper IT' of this series has shown that the network model has flow properties similar to those observed on real porous media. The comparison of properties of single size tube networks with those of real porous media cannot be carried far because very few porous media have uniform size pores. The capillary pressure curve from most porous materials such as soil, sandstone, and sintered glass indicate that these materials have pore size distribution similar to those shown in Figs. 5-1, 9-1, and 10-I.† To properly test the network model, it is therefore necessary to compare the dynamic properties of real porous media with those of networks of tubes in which the tube radii are distributed accord- ing to the distributions in the aforementioned figures. A network in which the tube sizes are distributed cannot be treated in the same manner as a network of single size tubes. In the single size tube network, the relation between tube geometry, flow resistance, and tube volume did not have to be known if the assumption was made that whatever relation did exist was the same for all tubes in a particular network. In a network of distributed tube size, the relation between tube geometry and flow resistance must be known or assumed in order to replace the tubes by equivalent electrical resistors. Relation of Tube Geometry to Flow Resistance The interchangeability of tubes and electrical resistors in the network model is possible because of the analogy between Poiseuille's law and Ohm's law. Poiseuille's law for a cylinder is q= pr4/8µl ?P.........(1) where q is the volumetric rate of flow, µ is the viscosity, ?P is the pressure gradient, r is the tube radius, and 1 is the tube length. Ohm's law is I=1/R?E..........(2) where I is the flux and is equivalent to the volumetric rate in Poiseuille's law, R is the resistance, and ?E is the voltage gradient. Both laws give the flux as a function of the potential drop and the resistance of the medium. By analogy then, 1/R=pr4/8µl ?P...........(3)

Jan 1, 1957

By H. P. Greenwald

THE rapidly increasing use in coal mines of portable auxiliary fans, which are generally "blowers" employed in connection with canvas tubing, raises questions concerning the hazards of such equipment, especially where the practices are opposed to established methods of ventilating face workings. Half a dozen or more coal-mine explosions and some fires have been attributed to the use of auxiliary fans; moreover, competent mining engineers have found many dangerous installations and methods of use-for example, intermittent running of the fans in gassy mines with consequent accumulations of firedamp at the faces. These facts have led the U. S. Bureau of Mines to issue this recommendation: "In the interest of safety, the Bureau of Mines, Department of Commerce, recommends that auxiliary fans or blowers should not be used in coal mines as a substitute for methods of regular and continuous coursing of the air to every face in the mine." The comparatively recent introduction of new types of mining machines, mechanical loaders, face conveyors, and slabbing machines has encouraged the trial of new systems of face mining, all of which have for their object the rapid advance of the faces. Although the latter has certain economic advantages, in gassy mines the rate at which gas is given off is generally found to increase in proportion to the speed of advance into new territory, which in turn increases the difficulties of efficient ventilation of the face workings. Some of the systems of advance mining being tried in connection with new mechanizing methods practically compel the use of blower fans and tubing, as single narrow places are now driven, 300 ft. or more without crosscuts. In some instances a series of parallel headings are driven without crosscuts pre-

Jan 1, 1928

By Fred D. Rosi

Introduction There is probably no field in which materials research has played a greater role than that of electronics. However, to trace present and future patterns of materials research in electronics is not an easy assignment, since this industry has a high degree of dynamism in its growth, and is busily engaged today in the scientific improbabilities of only recent yesterdays. On the other hand, this task seems especially appropriate since electronics is a truly frontier industry - one whose place in American industries has advanced from 50th prior to World War II to 6th in 1967, with sales of more than $22 billion. And this growth has been associated with the equally rapid progress of science and technology over the period - in particular with the emergence of materials science as a vital force in underscoring this progress. For several reasons this parallel growth is not too surprising. First, by its very definition electronics is a science that essentially deals with the nature, behavior, detection, generation, control and utilization of electrons in solids or at their surfaces. Second, in the electronics industry, systems are made of an integration of components, and these components with their interconnections are made of materials. Thus, the basic building blocks of systems are materials; and it has been largely the advances in materials research and technology that have led to new and improved devices and systems. It follows, therefore, that the broadening of the frontiers in electronics through the exploration of new territories is tantamount to scientific discovery and materials innovation to a degree found in no other major industrial activity. But to put this in the proper perspective of present and future materials trends, it would be appropriate first to survey historically the progress in electronics by pointing out major scientific discoveries and associated materials research patterns that have led directly to its tremendous growth. Then from this base we can consider recent trends in materials research that could form the basis for future progress in the electronics industry. In my review I shall examine the areas most familiar to me, so I must acknowledge at the outset that this survey is not all-inclusive.

Jan 1, 1971

By Carl Allen

INTRODUCTION IN any discussion of mining one is repeatedly confronted with the difficulty of dealing with so many variable conditions. It is not an exact science and in the choice of a method each varying factor has a certain weight, which, in many cases, experience alone can determine. In mathematical terms, it is a function of many variables. A discussion of mining also loses much of its value unless, costs are considered, because the expectation of profit is the only excuse for carrying on mining at all. As conditions vary they cause fluctuations in cost and there are few operations to which a definite cost can be assigned. The character of the ore may make it difficult to drill, yet because of the ease with which it breaks the total cost of drilling and blasting may be low. In preparing this article the attempt has been, not to cover the whole field of mining, but to describe the different methods of stoping and mining which have distinct principles. In addition to this an effort has been made to show the advantage of dissecting the methods into their detailed operations and applying to these a mathematical study as an aid to the judgment in determining which is the best method to adopt, or in attempting to reduce the cost of a method already in use. Methods of mining include stoping, caving, and various methods of working large deposits which, in addition to the method of actually breaking the ore, require elaborate and definite plans of, development of the orebody. The ordinary methods of stoping are too familiar to all for any elaborate discussion, but it has seemed advisable to review the subject and give the principal advantages' and disadvantages of the different methods.

Jan 8, 1914

By Charles W. Goodale

The purpose of this paper is to review the history of the Drumlummon, one of the famous old mines of the West. Mining engineers, when sent to examine new mines in old districts, or, to decide whether an old property, under new conditions, will pay to reopen, have had difficulty in learning anything authentic regarding workings which are under water, and historical facts about the working character of the ore, the total production, and the value of the ore with increasing depth. 'Not many years elapse after the pumps are pulled, before maps, books and records are destroyed, and the value of the publications of the Institute would be increased if they contained the history of many old mines now abandoned. The unsuccessful efforts of the writer quite recently in trying to obtain reliable information about a gold mine which was reported to have produced several million dollars between 1880 and 1888, the workings of which are now partially caved and under water, impressed upon his mind the desirability of having a permanent record of old properties. In this particular case, the owners insisted that under present conditions of improved methods of treatment —particularly by the use of cyanide, which was not an applied process when the mine was operated, the property could be made to pay a handsome profit on ore left in sight in the old workings, but no assay records could be found to confirm these assurances, and even the records of bullion shipments had been destroyed. If surveys and maps were made as the work progressed, no trace of them could be found, and therefore opening of the ground through a new shaft and drifts therefrom would be attended by some risk while exploring near the old workings. Fatal accidents by flooding under these conditions have occurred, and as an evidence that miners have fears of such dangers, it was urged upon the Mining Committee during a recent session of the Montana Legislature, by a delegation of

Jan 1, 1915

By Frank Tolonen

IRON-ORE beneficiation is becoming of vital importance to the Lake Superior region, since only a few decades will be needed to exhaust the direct shipping ores even if generous allowances are made for discoveries of new orebodies. If the region is to continue as the chief source of ore to the steel industry of the United States, it must concentrate or otherwise beneficiate the enormous tonnages of available iron formations. A beginning along this line has already been made. About one-fifth of the total shipment, even now, is the product of some sort of concentrating process, while another fifth is improved in physical structure by crushing, screening, drying, sintering, or some other similar method. The amount of material amenable to these processes is limited, however; and, in order to be able to utilize the billions of tons of iron formations that cannot be so beneficiated, an intensive study of their nature and concentration possi-bilities is necessary. As long as high-grade ores are available in ample quantities, ore dressing is economically impossible, but as soon, as the supply nears exhaustion it becomes necessary. At first the products of ore dressing must meet as nearly as possible the same specifications as the rich ores in order to be adapted to the reduction processes already established. The future requirements as to quality will depend on the one hand upon the ability of the ore dresser to eliminate undesired constituents and charac-teristics in the material, and on the other upon the adaptation of the reduction processes to the product that can be economically supplied. A better understanding of the blast furnace and other reduction reactions, and improvements in the preparation of raw materials, should enable the Michigan districts to continue to supply ore for a long time to come. The study and testing of the iron formations necessary to bring a utilization of the low-grade ores, though requiring time and effort on the part of all concerned, should not be postponed, especially since the economic situation forces the use of the highest grade ore in preference to the leaner material.

Jan 1, 1933

By D. H. Newland

During the year 1907 an investigation of the Clinton formation in New York has been carried out under the direction of the State Geologist, and a full account of the results has been prepared for publication.' The more important economic features of the report are summarized in the present paper. Previous knowledge of this, the type, section of the Clinton has been contributed mostly by Hall and Vanuxem in their reports for the Natural History Survey of New York, which were issued in their final form in 1842-43. Brief accounts of the ore-occurrences have been given by 13. T. Putnam? J. C. Smock: A. H. Chester: and E. C. Eckel.5 Prof. C. H. Smyth, Jr.,6 has discussed the origin of the Clinton ores in two papers, which, so far as the local occurrences are concerned, have removed all doubt that may have existed on that subject. Distribution of the Clinton Formation. The Clinton strata in New York State are restricted to a single belt, which extends from the eastern central part to the Niagara river, which it crosses, and thence continues for some distance into the province of Ontario. The New York

Jan 1, 1910

By A. J. Phillips, A. A. Smith, J. S. Smart

The preparation of a sufficient quantity of high-purity copper for extensive laboratory use in the study of impurity effects has been an integral part of a research program in progress at the Central Research Laboratory of the American Smelting and Refining Co. for the past several years. Initially the degree of purity desired was that necessary to meet two essential requirements for experimental accuracy: (I) no impurity was to be present in the copper in an amount capable of producing a detectable effect on the properties to be studied, (2) even the minor changes in propertties caused by the addition of extremely small amounts of individual elements were to be measured without significant interference from contaminants. In the course of the investigation, evidence has accumulated to justify the conclusion that this copper is of exceptional purity; in fact, no impurity can be detected by any chemical method or spectrographic technique known to the authors. The present paper describes the method of production of the copper and presents some of its properties. Preparation oF High-purity Copper The elimination of impurities from commercial electrolytic copper is accomplished by a three-step purification process. The first operation consists of an electrolysis through a purified CuSO4-H2SO4 electrolyte using bagged anodes, low current density (5 amp. per sq. ft.) and low tem- perature (25°C max.). The electrolyte is prepared from commercial Cu2SO4 and is purified by heating the solution and adding I gram Fe as Fe2(SO4)3 to each 100 grams dissolved copper; sufficient hydrated oxide of copper, prepared from Cu2SO4 and NaOH, is supplied to precipitate Fe(OH)3, which carries down arsenic, antimony, tin, selenium, tellurium and other minor constituents. Silver and remaining traces of lead are removed by addition of Na2S to the acidified filtrate, which is then reatered after standing hot overnight. The cold solution is made up to 30 grams per liter Cu and 150 grams per liter H2SO4 and introduced without addition agents into the electrolytic system, which consists of a double row of hard-rubber battery boxes with the inside webbing and partitions removed, arranged in seven steps of ascending height. Electrolyte is uniformly supplied to the two highest cells by glass siphons operating from a constant-level reservoir, and flows by gravity through the bank of seven cells, entering each at the bottom and leaving at the top. Glass air lifts continuously supply the returning liquid to the constant-level reservoir for recirculation. Each cell contains three 4 3/4 by 4 3/8 by 1-in anodes cast from high-quality electrolytic wirebar copper, various lots of which have been used with equal success. The anodes are pinned to sheet copper hangars shaped to prevent crawl of the electrolyte to the multiple-wired bus bars—which would result in fouling of the contacts—-and hang inside wool flannel bags stretched over open wood frames. The deposit

Jan 1, 1941

By C. S. Roberts

Four binary alloys in this system were creep tested at 300°' to 600°F. A photographic study of microstructural changes showed that the outstanding creep resistance results primarily from a potent precipitation hardening locally at grain boundaries. Twinning was correlated with the primary stage and nonbasal slip with the tertiary stage of creep. THE utility of the rare earth metals as ingredients of magnesium alloys destined for elevated temperature application has been recognized for about 15 years. A review of the early development of these alloys has been given by Leontis. 1,2 It has been only recently that a desire has arisen to understand basically their remarkable creep resistance. The present research had that object. The work of Leontis showed that the differences between the behavior of the individual magnesium-rare earth element binaries was of commercial significance. However, the variations were small compared to the overall difference in creep resistance between the group as a whole and the magnesium alloys of the Al-Zn type. It was decided to conduct this investigation with one binary system which would be representative of the magnesium-rare earth element alloy group. Cerium was chosen as the solute because of its near-middle position in the series and because of its availability in the commercially pure form. A previously published description of the creep behavior of electrolytic magnesium" serves as the background to this research. The experimental approach used in that investigation has been partially repeated here. A series of binary alloys was planned to include the following: 1—A dilute alloy which would contain the cerium almost entirely in solid solution. This would assess the solid solution effect. 2—An alloy which is nearly saturated at the selected solution heat treatment temperature, 1070°F. Here the effect of nearly maximum precip- itation would be obtained without the influence of undissolved Mg-Ce intermetallic. 3—An alloy containing slightly more cerium than is soluble at 1070°F. This would allow the investigation of the effect of a small amount of excess intermetallic. 4—A high cerium alloy in which the influence of a large volume of undissolved intermetallic may be examined. Experimental Details In order to specify compositions of the binary alloy series a knowledge of the solubility of commercially pure cerium in solid electrolytic magnesium and also of the composition of the terminal intermetallic phase was necessary. The latter has been proven to be approximately Mg,Ce by Voge14 and Haughton and Schofield.5 A series of both cast and extruded alloys were solution heat treated 24 hr at 1070°F for a solubility determination. Lineal analyses of the polished and etched microstructures were accomplished with the aid of a Hurlbut

Jan 1, 1955