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By C. L. Dake

Discussion of the paper of. C. L. DAKE, presented at the San Francisco meeting, September, 1915, and printed in Bulletin No. 103, July, 1915, pp. 1429 to 1436. A. C. LAWSON, Berkeley, Cal.-It appears that our bog-iron ores are due in a large measure to the activity of certain iron bacteria, and a paper dealing with this subject that makes no reference to that particular agency strikes me as rather curious. C. L. DANE, Rolla, Mo.-Mr. Lawson's criticism that this paper makes no reference to the activity, of iron bacteria is scarcely true. On p. 1430 I stated: "Certain bacteria precipitate iron by building the hydrated oxide into their body cells," and again, "There are many other means by which, under special conditions, iron may be precipitated in nature. Oxidation, evaporation of CO2, and iron bacteria have been held to be the most important." Thus the activity of bacteria receives as extended mention as the action of any other agency in precipitation of iron. The paper makes no pretense of covering exhaustively the origin of bog ores, but, as its original title suggested, refers to Some Principles Controlling the Formation and Distribution of Bog Iron Ores. Mr. Lawson seems to have entirely missed the main thesis of the paper, which attempts to establish some relation between glaciation and abundance of bog ores now forming. Unfortunately, I have no immediate access to the literature of the subject, but my best recollection is that the data regarding iron bacteria throw no light whatever on the cause of bog ores being so much in ore abundant within the limits of the glaciated regions, and being reported much less frequently from the tropics. This lack of data is suggested in the following (p. 1434): "It has already been shown that bacteria aid in the precipitation of iron. Whether tropical conditions increase or decrease the activity of such bacteria is unknown."

Jan 12, 1915

By J. H. Bowden

The water-hoisting tanks herewith illustrated have been designed for removing large quantities of water from recently-flooded mines, through their hoisting-slopes, with rapidity proportional to the capabilities of the hoisting machinery available, the tanks being adaptable to slopes of small sectional areas and varying pitches. The following features may be of interest to those operating mines liable to be flooded. 1. The arrangement of doors on each tank by which it may be automatically filled by immersion at any point on the varying pitch of a slope, the water being retained while hoisting on the flat as well as on the steep pitches, and quickly and autoniatically discharged at the top. 2. The arrangement, in connection with the above-mentioned doors, of side-wheels over the rear wheeh of each tank and of sidedumping tracks at the top of the hoist, for the automatic emptying and quick return of the tank. 3. The arrangement of two or more tanks, one in front of the other, so as to give as large a capacity in a single hoist as the enginepower will permit, yet without making any tank too large for the sectional area of the slope, or of unwieldlp length, or of such a shape that it cannot easily pass over vertical curves; and without concentrating too much weight on any one pair of wheels or on any point of the track. The details of construction and method of operating are shown by the accompanying sketches (Figs. 1 and 2), and the following more detailed description. At the end of each tank is a large iron door of almost the full size of the end of the tank, opening inwards, so that when immersed the tanks fill almost instantly. To provide for holding the water while it is hoisted up flat pitches, a wooden door is attached to the front of each tank, opening outward. Each front door is attached to the

Jan 1, 1892

By D. W. Mitchell

J. H. Schlobohm (Joy Manufacturing Co., New York) —This paper has been read with a good deal of interest; however, there are several salient features which Mr. Mitchell has overlooked. The initial emphasis on selection should be placed on type of material to be loaded and method of mining involved. There is no possible connection in the comparison of scraper or Joy Lohite loaders with loaders of any other type. Neither can an operating comparison be made between "Rocker type" loaders and those equipped with loading head and gathering arms. Each unit has its application, but the application depends on material and the mining system involved. Mr. Mitchell's compilation of data on various loaders, while it represents a great many facts, does not represent true operational data, i.e. Table I, column heading "Max. Rated Capacity for 7 hr;" these figures are meaningless inasmuch as little or no time at all is allowed for tramming or switching or moving the loader from place to place. Table I, column heading, "Best Reported Field Shift," would be a better source of operational data, assuming of course that conditions, applicable to each class of loaders, were average to avoid enthusiastic performance figures. Table I, column heading, "Repair Parts Cost per Ton," is still another item which will not stand up under comparison unless the loaders involved are put into type classes, i.e., there are simply no means possible to show the repair costs of scraper loading versus a caterpillar mounted loader in abrasive material. The source of information here is also important. Actual field tests have proved that these costs are of a constant nature. Manufacturers are striving to hold them to a minimum and many interesting studies have been made. A fairly recent example of this in a large United States gold producer has proved that Joy HL-3 loaders can be consistently average, less than $0.025 per ton mucked. This cost represents repair labor and parts over a two year

Jan 1, 1952

By P. Bouéry

This account of a contrivance which has been found serviceable in practice may be of interest to engineers, and especially to those engaged in hydraulic mining. In that process, one feature which seems at first sight to possess little significance, is highly important in its effects—namely, the regular supply of water to the " giants." The chief condition of this regularity is an even flow in the pipe-line from the penstock to the nozzle.' This, of course, requires that the penstock be kept full. Any considerable surplus of water, overflowing at the penstock, is a simple waste, unless it be otherwise utilized in the sluices. At all events, it does not affect the delivery of the nozzles. But a deficiency at the penstock may admit air into the pipe; and this may produce hydraulic recoil, injuring the line by incessant vibrations, giving rise to leaks, and even to blow-outs, and (when a partial vacuum exists at the time of the fracture) the collapse of the pipe. An accident of this sort in our main pipe-line, occasioned partly by a settling of the ground and partly by the presence of air in the pipe, led to the employment of the device here described. The line referred to is made of 30-in. pipe, successively reduced to 18 and 15 in. in diameter, for the supply of two giants. By reason of the causes above mentioned, the 30-in. pipe burst more than 1,400 ft. from the penstock, and, despite the air-valve, the 30-in. pipe was collapsed to such a degree that one length of it, next to the penstock, was squeezed together and positively swallowed by the main pipe, through which it traveled for 750 ft., piercing through a short elbow on the way. This remarkable result was undoubtedly the effect of the vacuum suddenly produced when the pipe burst.

Jan 1, 1907

By C. E. Meissner

THE need for a practical method of deciding upon new alloy steel analyses to widen its markets was the problem facing the Chrome Steel Works at the beginning of 1927. In addition to determining the physical properties of the alloys under consideration, it was necessary to test their value in service. Small melts of steel in a crucible, from which test specimens could be made, were insufficient to determine more than physical properties, therefore actual castings and ingots had to be made before the products could be placed in service. Furthermore, to save further experimental work, it was desirable that these heats should be made on a "pilot" basis; that is, actually duplicating regular open-hearth furnace practice. Therefore a one-ton (2000-lb.) acid open-hearth furnace was built. FURNACE DESIGN There are no special features in the design of this furnace. Standard acid open-hearth practice is followed, with the reproportioning of the dimensions necessitated by its small size; notably, a considerably increased length in proportion to width in order to get proper flame propagation. After the first heat was made it was found that the checkers were insufficient. The checker chambers were increased in size and the checker openings were made much smaller. The furnace was started late in March, 1927, and made 65 heats. Experimental work was then stopped until the data accumulated could be worked up and summarized. The run was resumed in November and the furnace is still operating, having made at this writing 60 additional heats. For the last series of runs, there was some rebuilding of both the furnace itself and the checkers. Slag pockets were added. Fig. 1 shows details of construction; Fig. 2, the, general appearance. All designing was done by the operating and engineering staff. Construction materials were those available around the plant. The reversing valve is a standard butterfly type taken from an old furnace.

Jan 1, 1928

By G. L. Craig

COPPER containing a small amount of arsenic has been used extensively abroad, and a number of reports, particularly those by English workers, have indicated that such copper is better suited for certain uses than high-conductivity copper. Inasmuch as a large percentage of the copper fabricated is used for nonelectrical purposes where high conductivity is not at all essential, it has been suggested that arsenical copper might be at least as suitable as high-conductivity copper for many purposes. An investigation spon-sored by the Calumet & Hecla Consolidated Copper Co. at Battelle Memorial Institute was therefore undertaken with the object of determin-ing the effect of small amounts of arsenic (up to 0.75 per cent) on the properties of copper. In this work the effect of arsenic on the basic properties of tough-pitch and of phosphorized copper have been critically studied and many data collected from laboratory experiments which have been supplemented by mill-scale tests. The results of these tests, with coppers of the type referred to, in the annealed condition and after various degrees of reduction, show that the basic properties of copper are not greatly affected by small amounts of arsenic, an increase in strength being observed with increasing arsenic with no corresponding decrease in ductility. It is well known that the evaluation of material for plastic deforma-tion, on the basis of laboratory tests, may not be directly comparable with its performance in commercial operations. In order, therefore, to substantiate the data obtained at the Institute, the cooperation of the Wolverine Tube Co. was obtained for a series of production tests on the fabrication characteristics of phosphorized arsenical copper in the manu-facture of seamless copper tubing. In these tests the behavior of the arsenical coppers was carefully observed in comparison with that of representative types of phosphorized arsenic-free copper, which were fabricated under the same conditions.

Jan 1, 1933

By M. H. De Hora

(Butte Meeting, August, 1913.) IN giving my opinion of the importance of Colombia as a field for investment for those interested' in mining for the precious metals, I must begin by quoting Sir Clement Markham, who, in one of his presidential addresses to the Royal Geographical Society of Great Britain, called the attention of its members to the fact that " although Colombia is the least known and least developed of the South American republics, it is far and away the richest mineral country of them all." This to American investors is extremely interesting, as the country is the most accessible of all the South American republics from the United States. .Almost all of the gold shipped by the Spaniards from Madre de Dios, now Colon, came from Colombia, and statistics from the Mint at Medellin, the capital of the Department of Antioquia, go to show that the . total production of the precious metals of Colombia, dating from the Spanish conquest in the fifteenth century to the present time, aggregates the enormous total of $700,000,000. Of this amount, nearly 70 per cent. represents gold obtained from the placers of the Republic, more than one-half of which came from the Department of Antioquia, the balance, being divided between the placers of the Choco and the rest of the Republic. The remaining 30 per cent. of the $700,000,000 represents the silver and gold obtained from the quartz mines, the silver greatly predominating. A glance at the map of Colombia shows the territory somewhat in the shape of an outspread human left hand extended palm downwards on the paper, with the wrist adjoining the Republic of Ecuador, the bones of the hand, fingers, and thumb representing the divisions of the great Andean mountain chain known as the Cordilleras of Colombia. The first finger represents the Eastern Cordillera, with the thumb as the extension to the Nevada de Santa Maria, forming

Jan 7, 1913

By J. R. McWilliams

THE task of recovering most of the contents of an oil and gas reservoir economically presents many and varied problems. In order to attempt intelligently a solution to these problems, an understanding of fundamental physical laws is essential. As the pertinent facts needed in applying these laws to recovery problems are not readily obtainable, observation must be made and the data tabulated. Here, good judgment must be exercised, for at best the information is meager. The engineer is well fitted to undertake the task of solving this problem. In my opinion, the decision on the part of some production executives to allow the engineer to cope with the oil recovery situation and other problems, is an outstanding example of improvement in production methods. The executive head must make this decision or the qualified engineer will be working under a severe handicap with the present system of supervising the production of oil and gas. A qualified engineer should have not only the required technical training but also enough field experience to enable him to understand the difficulties encountered in producing oil and gas. Such a man tactfully cooperating with the practical oil man can greatly improve present methods of oil recovery. The realization that nature's forces have not been efficiently controlled in past recovery of petroleum deposits has recently brought distinct improvement in production methods. Papers are to be presented at this meeting discussing in detail improved methods of conserving gas in both flowing and pumping wells, and also methods of lifting oil after Nature's supply of gas has proved inadequate. The application of back pressure to producing oil wells has not, to my knowledge, been extensively applied in Oklahoma or Kansas up to the present time. Most of the flowing wells are allowed to flow through the casing until the rock pressure has been dissipated. However, some flowing wells have been tubed before the well stopped flowing through the casing. Recording pressure-gages can be installed to study well performance.

Jan 11, 1926

By Lewis T. Wright

It is commonly believed by metallurgists that in copper-smelting, the copper in the slags, which is irreducible by continued " settling," is retained in the form of " prills " of matte. I have frequently held well-settled slag in a molten condition for a long period without being able thereby to reduce the copper-content. The slag acted as though it contained a minimum of dissolved or combined copper that could not be settled out by gravity. I have used reagents, but without satisfying myself in what form this copper existed. The same slags, by fine grinding and elutriation, could not be separated into portions containing more or less copper than the average content. By treating copper-slags in an electric furnace a button of metallic iron and copper was produced, but the high temperature and the strong reducing-action of the furnace mere influences that suggest an explanation of a result not obtainable with ordinary smelting-temperatures. If all the copper in the slag were in the form of copper-matte, and not existing as a dissolved compound with some of the elements of the slag, then the other metals in the matte, such as gold and silver, should occur in the slag in the same ratio to the copper as to the copper in the accompanying matte. This reasoning led me to study the ratio of metals in the products of smelting, and, apart from the issues discussed in this paper, the research has proved both interesting and illuminative. On the assumption of a similar ratio of metals in matte and slag, if the percentage of copper in the slag accompanying a matte containing 50 oz. of silver and 1 oz. of gold per ton of copper was 0.3 per cent., or 96 oz. per toll of slag, there should be found 0.15 oz. of silver and 0.003 oz. of gold per ton of slag; but, in my experience, there is less silver and much

Jan 1, 1910

By S. J. McCarroll

J. Bruce Clemmer, J. B. Rosenbaum, and C. H. Schack (U.S. Bureau of Mines, Salt Lake City)—We have watched with considerable interest Three Kids development of Manganese Inc. and have been impressed by the ingenuity with which management and staff have solved their many obstinate handling problems. Mr. McCarroll has been lenient in describing the difficulties faced by the company in developing a process for beneficiating Three Kids ore. The operation, equivalent in size to a 20,000-ton sulphide ore plant, is treating a unique ore by a flotation process pioneered by Manganese Inc. Perhaps the magnitude of the conditioning and flotation problems peculiar to Three Kids ore can be better appraised when it is pointed out that two-thirds to three-fourths of the ore is floated in the rougher step and that the four stages of cleaning which follow are equivalent to floating the whole plant feed two to three times. Our experience in both laboratory and pilot plant flotation of Three Kids and other manganese ores leads us to agree with Mr. McCarroll that suitable conditioning is a prime requisite for successful oil-emulsion flotation. The difficulties of proper conditioning were demonstrated in pilot plant processing of Artillery Peak manganese ore at our Boulder City, Nev., experiment station. Over three months of experiments and extensive plant revision were required before satisfactory conditioning was obtained in the 25-ton-per-day plant. Such factors as time, type and intensity of mixing, aeration, surface to volume relationship, and power input are still being studied by the Bureau of Mines in hopes of learning how best to condition manganese pulps for oil-emulsion flotation. Other factors affecting flotation of manganese with oil emulsion also deserve attention. A few of these are the influence of stability and proportion of ingredients in the collector emulsion, the feasibility of grinding

Jan 1, 1955

By Robert W. Pack

Sooner or later in the development of any natural resource it becomes highly desirable to know the quantity of this resource in the country as a whole, as well as of the part that is being developed, for the general course and conduct of the development work must be governed, to some extent, by the total supply available. An accurate estimate of the quantity of any natural resource is difficult to make; yet if one is diligent enough one can obtain a pretty accurate idea of the quantity of marketable timber, the acreage of tillable land, or the horsepower that may be developed from the streams, for these are things that may be measured. But any attempt to estimate the quantity of some mineral in the ground appears to enter the realm of imagination and it seems that the estimate can be nothing more than a blind guess. It may appear to be especially futile to attempt to determine the quantity of oil and gas that is available in the ground, for these minerals are so vagrant that even if the quantity now available should be known quite exactly, the quantity that will eventually be obtained may be much less, for certain losses in the extraction of both oil and gas are unavoidable, and just what these losses will be cannot be predicted. Though necessarily inaccurate, estimates of such mineral reserves are, however, of distinct value, for they summarize the existing knowledge of the deposits of the mineral and thus enable those who are interested in some industry that depends in one way or another on this mineral to formulate a rational commercial policy. Some time ago, when the price of gasoline suddenly rose in a rather spectacular manner, the writer was one of the U. S. Geological Survey geologists called upon to help to estimate the quantity of oil that could be obtained in the United States, for the fear had become widespread that perhaps the rate of increase in the price of gasoline was a measure of the rate of depletion of the supply of petroleum. It thus became his

Jan 1, 1918

By Carl O. Theime

Industrial specialization has rapidly created a demand for new and better alloys. A more thorough understanding of the requirements of specific industries and the discovery of processes by which it has been made possible to utilize certain metallic elements in larger quantities, together with greater purity in most virgin metals, has resulted in a great increase in the number and variety of alloys. This increase in the number of elements entering into non-ferrous alloy manufacture has increased the contamination in secondary metals, as received by the smelter. In order to successfully refine scrap of a much more complex nature it has been necessary for the smelter to install new equipment and to constantly search for new methods of refining as well as to improve the methods already in use. In some instances it is largely responsible for specialization in the secondary metal industry. It is usually necessary to remove the contaminating impurities in scrap or eliminate to a degree not objectionable, no matter how introduced. In order to know what metals or elements are of an objectionable nature, the smelter must make a study of the effect of single elements and combinations of elements on many of the physical and mechanical properties, such as strength, ductility, color, hardness, casting soundness, etc. The smelter of secondary mctals must be able to utilize scrap materials of all kinds, for, sooner or later, most fabricated metal parts and the waste products formed during the process of manufacture find their way to the smelter. In addition, the smelter, in contracting for salvaged material from the producer, gets some undesirable and unusual materials. The value of secondary metals and the importance of their recovery has increased in recent years and it is no longer sufficient to recover the base metal only, such as copper from copper-bearing material, but it is essential that other elements present be recovered and converted into useful form. This paper will deal not with the smelting and refining or separation of impurities from secondary metals but an attempt will be made to show the increased value of metal scrap when properly segregated and in a less contanlinated condition. There are five principal reasons for contamination in secondary metals: New and unusual alloys, productive methods,

By H. R. Barnhurst

It would be a difficult matter to trace from the beginning the very few improvements made in the burning of fuels prior to 1860. Donbtless the crossing of the sticks of wood in building a mood fire early appealed to our savage ancestry as a means of expediting its effectiveness for their crude culinary purposes. Stones and andirons came later in assisting the admission of air to the under part of the fuel bed, while beacons and cressets, utilized metal bars as supports for the same purpose. It is probable that Tuba1 Cain owed his success to the use of bellows making possible the use of mixed fuel and charge upon a hearth. With the development of working in cast iron, grate bars came in, and they are still with us doing duty in every household and almost every art where heat is a factor. Little was done beyond these crude methods prior to 1860. With the advancement of knowledge came the fuel-gas producer, a natural child of the retorts employed in supplying illuminating gas. It is only within the last 15 years that the conclusion became general that complicated systems for saving heat would not remedy deli-. ciencies in its primary development, and within that time there has been great advancement in the means of producing initially a fire of high effciency, so that to-day we are moving rapidly toward both high development and high absorption, with the resultant of high efficiencies. In studying the subject of the availability of pulverized coal as a fuel, it may occur to ask, why has this not come up earlier? This, question would be naturally prompted by recalling the fact that Thomas Crompton's English patents upon his methods were issued to him nearly 40 years ago. A conclusive answer to this, however, is that Crompton at that time had very crude facilities for making what was at best a very imperfect pulverization of the coal, arid the expense of preparation mas very great. He does not seem to have been aware of the advantage of a thorough drying of the coal in the

Jan 1, 1914

By B. L. Sackett

The converting of lead matte is not a general practice at lead smelters, therefore a description of the methods used and developments made during the past 20 years in converting both lead and copper matte at the Tooele plant of the International Smelting Co. in Utah may be of interest. The Tooele converting plant consists of five electrically operated stands in which are used 96 by 150-in. horizontal, barrel-type converters each of about 10 tons capacity. The main converter building is served by a 60-ton electric traveling crane and the casting shed by a 30-ton crane. Copper matte is tapped from near-by reverberatory furnaces into launders that deliver into 8-ton ladles on the converter floor. Lead matte is brought from the blast furnaces, about li mile away, in 5-ton ladles mounted on trucks, hauled by electric locomotives. As the Tooele copper plant has never been a producer of much copper, and has been Irregular in its operation, the original converting plant with its small converters has been adcquate, although decidedly out of step with large, modern plants. Tonnage figures in this paper are for comparison with each other only, as they are not at all in line with prevailing tonnages at larger plants today. The reasons for the changes made in converting practice at Tooele, as well as the improvements in the results obtained as these changes were perfected, are given in the following pages. Lead-matte Converting, 1914 to 1927 In 1914, Oscar M. Kuchs wrote a paper for the Transactions,' describing in detail the lead-matte converting methods at Tooele up to that time. The method perfected only a few months before Mr. Kuchs' paper was written consisted, briefly, of blowing the lead matte alone, without the addition of siliceous fluxing ores, to a point where the lead and zinc were largely eliminated by volatilization. During this period

Jan 1, 1934

By G. C. Stone

At the conclusion of my paper on the same subject read at the Boston meeting of the Institute, I offered to send some of sample No. 2 to any chemist who wished to analyze it. Eight chemists wrote to me for samples; so far I have received results from five. I give these results in a table (on the following page), together with the results previously obtained: As to the chemists and their methods : K is an iron-works chemist whom I only know by correspondence; lie writes: "No. 27(13.64) was obtained by the method I generally use, as follows : Dissolve 0.8 grams spiegel in hydrochloric acid and a little potassium chlorate, in a half-liter flask. Boil off most of the acid, add ammonia in slight excess, redissolve in acetic acid, using rather more than is really necessary, and then add 8 or 10 grams of sodium acetate and make up to the mark with warm water. Boil hard for fifteen minutes, then allow to settle (cool?), until the liquid reaches the mark, and withdraw 300 C.C. of the nearly clear liquid. Add to this an excess of hydrochloric acid, evaporate to dryness, take up with hydrochloric acid and water, and separate the iron by two precipitations with ammonia (I have often tested the ferric hydrate for manganese, but have never found any, if the separation by ammonia was properly made). Finally, precipitate the manganese as phosphate." Nos. 28, 29 (13.35, 13.07) were by Ford's method." No. 30 (13.50) was by Troilus's method He writes, " I may add the results are quite as good as I expected, although for any element except manganese, they are not close enough for anything like accurate work." L is a firm of commercial chemists of large experience who have made a specialty of iron work. Their method is as follows : Dissolve

Jan 1, 1884

By William P. Blake

In addition to uintaite, the Uintah Mountains contain a deposit, or vein, of the peculiar hydrocarbon mineral, to which I have given the name wurtzilite, * in honor of the chemist, Henry Wurtz, Ph.D., of New York, who, in 1865, described grahamite, and who has added to our knowledge of the composition of the hydrocarbon minerals. Wurtzilite and uintaite are very similar in appearance, but are very different in their physical and chemical properties. Both are black, splendent and shining in fresh fracture; but the wurtzilite has a decided toughness, and a degree of elasticity, especially when warmed, which suggests to some persons a resemblance to caoutchouc. It was at first, at Salt Lake, believed and reported to be a mineral form of India-rubber, and great expectations of its value as a substitute for crude rubber were indulged in. It was, however, found that it would not act like rubber with sulphur; it would not incorporate with it and become "volcanized," and it was very refractory and insoluble in the ordinary solvents of rubber and of uintaite. The elasticity, though unlike the elasticity of rubber, led to the reference of the mineral to the species elaterite, the only name under which an elastic bitumen is described in the mineralogies; and it is so called in the list of the mineral products of Utah, given in the last message of the Governor of the Territory. The name elaterite, as used by Dana, covers at least three differing substances, ranging in specific gravity from 0.905 to 1.223. Two of the varieties are soft and elastic, much like India-rubber, and one is occasionally hard and brittle, imbedded in the softer kinds. All are rare, and comparatively unknown, and not generally represented in mineral collections. One of the varieties referred to here is the subterranean fungus from Derbyshire, described by Lister as early as 1673.

Jan 1, 1890

By E. A. Beck

For a number of years many attempts have been made to use thermit in order to do away with piping in ingots. Some of these attempts were successful, while others did not give the expected results. Nearly every plant had its own method of using the thermit, and no special care was taken to study the results or to find the causes for lack of success. Formerly the principle of the process was to decrease the piping by introducing a can filled with thermit, attached to an iron rod, into the head of the ingot directly after it had been poured. In this case the thermit reaction took place in the upper part of the ingot, and it was thought that through the heat produced the head would keep liquid longer and piping thus be reduced. In other words, the aim was to keep the head of the ingot open by making use of the heat of the thermit reaction, which would thereby give the gases in the steel sufficient time to escape. This result can be attained by the application of a large enough quantity of thermit, but it would not be economical in general practice, and could only he used for high-grade material. Many steel-makers abroad and in this country have had this experience. The Th. Goldschmidt A. G., Germany, has, therefore, made a special study of this question with the cooperation of a well-known steel company, and has worked out a new method for the application of thermit for this purpose. The results obtained have been most satisfactory and reliable, and this process is now used in Germany on a large scale in many prominent steel-works. The thermit is applied in cans, as in former years, but the principle of the process is entirely different. The object of using the thermit is not to heat the steel and keep it liquid,

Jan 1, 1914

By A. B. Kinzel

A PREVIOUS study1 of the relations of impact strength to inclusions showed that the dynamic strength of steel is lowered by the presence of visible counted inclusions, but that other factors comprised in the term "body" have a marked influence. The previous work was carried out on selected steels from a single source, so that the body factor was purposely minimized, but even under these conditions it was found that inclusion counting or the use of the commercial inclusion rating is not satisfactory. The tensile-impact test, however, was indicated as a satisfactory measure of dynamic strength. It was further suggested that the tensile-impact test should be so standardized as to be suitable for use in specifications, and that the hardness factor should be worked out over a sufficient range to admit ready commercial use of the tensile-impact test. In accordance with these suggestions, and in view of the fact that the steels reported in the previous paper were selected and treated so as to have a minimum variation in body, hardness and structure, further work has been performed on a variety of steels which are not limited by these conditions. The word "body" is used here for want of a better term. It is simply a convenient expression which comprises the effect of the various unknown factors that modify the dynamic strength of the steel. Thus at our present state of knowledge, the writers have chosen to consider hardness, structure and counted inclusion content as factors not comprised in the term "body," and such factors as raw materials, process of melting, fabricating, etc. as comprised in the term "body." Numerous grades of steels made in several ways have been taken from different sources and have been heat-treated to varying hardness by normalizing and by quenching and drawing. The results, therefore, may be considered to be generally applicable to current engineering steels. A certain limitation with respect to the hardness at which steel should be

Jan 1, 1931

By J. W. Ristori, V. R. Garfias, R. V. Whetshel

During the past eight years, in trying to estimate world consumption of petroleum and related products, the authors have been unable to account for all the supplies available in any one year. There has remained at all times a balance, which at first was thought to represent almost entirely additions to stocks in foreign countries. But as this discrepancy continued year after year-over 148,000,000 bbl. in 1937—it became unreasonable to conclude that corresponding additional foreign storage capacity was continuously being made available. It became therefore clear that the balance in question was due to other causes than to additions to stocks. Last year Mr. A. G. White, Chief Economist of the Petroleum Economics Division of the United States Bureau of Mines, pointed out to one of the authors that an unknown and important factor in consumption of petroleum and related products is to be found in the requirements for military purposes in foreign countries. This paper is the result of Mr. White's timely suggestion. There are no reliable data available either on the storage capacity, and therefore oil stocks, or on the petroleum consumption for military purposes in foreign countries. This information is so closely related to national defense that its divulgation is forbidden. One can therefore but surmise as to these facilities and needs in line with the relative strength of the military land, air and sea forces of the various countries. The authors have assumed many of the component factors that go to make the tables herein presented, such as fuel consumption of fighting ships in relation to tonnage and horsepower, gasoline consumption of air fleets in relation to number of planes, and the consumption of petroleum products by mechanized armies; but in making these assumptions they have availed themselves of the advice and counsel of those whose wide experience in these questions make their views authoritative. The opportunities for error in an estimate of this nature are obvious and ever present; to illustrate: The air fleets in Spain no doubt consumed

Jan 1, 1938

By Robert S. Shoemaker

At this Symposium on Gold which is sponsored by The Metallurgical Society of AIME and the International Precious Metals Institute many distinguished authors will present the latest developments in the metallurgy of gold and in operating practices at mines and in refineries. It seems appropriate then, as the introduction to this volume to recall some of the history of gold and the metallurgical developments which have been accomplished, especially during the past 100 years and some of the people who have contributed so much to the metallurgy of gold. Of all the elements gold has been the most sought after since the earliest times. Perhaps the quotation from Virgil's Aeneid best describes man's desire for gold but Pliny the Elder also put it very well when he wrote in 79 A.D. that "Gold is the first of man's follies, silver the second". This quest for gold has markedly influenced man's history and through the efforts of the early philosophers and alchemists to turn base metals into gold the foundations for modern chemistry were laid. The pages of history literally teem with references to gold. Gold is the first metal mentioned in the Bible and was the source of Croesus wealth as well as the death of King Midas whose touch turned everything into gold. And of course almost everyone has heard of Jason's Argonauts and the golden fleece. They are the subject of one of the many drawings in Agricola's De Re Metallica published in 1556. The Argonauts were probably prospectors seeking the source of the placers in the region near-the Black Sea. The time was about 1200 B.C. and the placer miners recovered gold by trapping the particles in sheep's fleeces placed in sluices. After drying, the fleeces were shaken to recover the gold. Gold is not hydrophilic, or wetted by water and thus the oils in the wool aided in collecting the particles. Here we have perhaps the earliest reference to surface chemistry and the basis for concentration of gold by flotation.

Jan 1, 1984