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By C. M. Tucker, Kent R. Van Horn, W. P. Sykes

RECENT investigations of the molybdenum-carbon alloys have been reported by Becker and Ebert1‡, Westgren and Phragmén2, T. Takei3, and H. Tutiya4. Takei3 studied the Mo-C system by employing metallographic and X-ray methods, and the other publications described the determination of the crystal structure of the molybdenum carbides. In exploring this system by a technique previously applied to the tungsten-carbon series5, the results of Takei were confirmed with two definite exceptions; i.e., first the composition of the eutectic, and second the nature of the carbon-fish intermediate phase. Consequently, a more thorough examination of the molybdenum-carbon constitution was initiated in an effort to correlate the data supplied by the microstructures, diffraction patterns and chemical analyses. METALLOGRAPHIC INVESTIGATION A briquette of molybdenum powder when heated in a carburizing atmosphere at 1500° to 1600° C. for several hours develops the carbon-rich layer shown in Fig. 1. The carburization was accomplished by placing the briquette in a carbon tube, which was heated in the hydrogen atmosphere of an alundum muffle wound with tungsten resistor. While the macrostructure indicates two distinct shells, and suggests the possibility of two carbon-rich phases, no evidence of this condition could be detected by the microscope, which revealed but one high-carbon constituent. This carbide forms next to the molybdenum as a relatively

Jan 1, 1935

By Thomas T. Read

THE fact that certain types of ore-deposits have attained their present condition through the action of descending surface waters was, perhaps, first clearly pointed out by Posepny.1 The oxidizing effects of such waters were discussed by Penrose,2 and many papers dealing with this phase of the subject have subsequently appeared. That secondary enrichment of sulphide ores, however, might be produced by descending surface waters was not clearly understood until after the copper-bearing veins of the Butte district, Mont., had been carefully studied by the geologists of the U. S. Geological Survey, al¬though De Launay3 had suggested that sulphides might be transported from point to point and re-deposited in the zone above the level of ground-water. As a result of the study of the Butte district, two papers by geologists engaged in the work appeared within a short interval. The first by Weed,4 dealing with the enrichment of veins by later metallic sulphides: and the second by Ernmons,5 treating of the secondary enrichment of ore-deposits in general. In the latter paper it was pointed out that a typical vein of sulphide ores which has been subjected to the action of descending surface waters exhibits four zones,-an upper or surface zone, in which the changes have been mainly of removal, the products being typically oxides; a second zone of oxide enrichment, in which the less soluble metals brought from above have been precipitated as carbonates or oxides; a third zone of sulphide enrichment,

Mar 1, 1906

By Gregory Dybalski

The purpose of this paper is to illustrate the forecast capability of the econometric model of the cobalt industry1/ as utilized by the Federal Preparedness Agency. Forecasts from this model are illustrated from the premise that the leading producer continues production of cobalt. An alternate forecast is presented where the model structure is altered to reflect the condition where the leading producer leaves the market. All estimations and forecasts presented here are shown for illustrative purposes. The cobalt industry is highly concentrated; one company, owned by the Zaire government, accounts for approximately three-fifths of world production. The cobalt supply outside of Zaire is determined by the level of activity of copper or nickel markets, as cobalt is mined as a by-product of copper or nickel. The demand for cobalt reflects a diversified usage pattern; cobalt is used mainly in heat and corrosion-resistant materials, high- strength materials and permanent magnets. According to 1974 U.S. consumption data superalloys accounted for 22%, magnetic alloys 18%, cutting and wear-resistant materials 13%, and catalyst 7%. Foreign consumption is probably similar in terms of usage categories, but the relative order of the categories is in variance.2/ The Cobalt Model The cobalt model's object is to explain consumption, supply and price movements by utilizing statistically estimated equations. Central to the econometric model is the role of Zaire as the profit-maximizing "dominant firm". Zaire sets the price that is most profitable for itself. The price of cobalt depends on industrial demand, production of other firms, and net exogenous purchases, such as government

Jan 1, 1977

By ROBERT R. ABUOTT

(Cleveland Meeting, October, 1912.) THE practice of carbonizing steel for the purpose of case-hardening has assumed great commercial importance within the past, 10 years. Formerly, case-hardened steel was held in more or less contempt, since it. was considered a cheap substitute for tool-steel. This is no longer the case. The development of the motor-car industry, and coincidentally that of modern alloy-steels, has resulted in overcoming many difficulties formerly experienced in case-hardening. This result has been accomplished by increased knowledge regarding the analysis of the steel which would respond most readily to case-hardening, and by more careful methods of treatment of the carbonized steel. The ordinary method of carbonizing consists in packing the steel with the carbonizing-material in cast-iron boxes and placing them in a furnace at a temperature of from 1,500° to 1,900° F. for a time sufficient to give the required depth of cc case." The steel is then either quenched directly from the box, or is allowed to cool without unpacking, and finally given a single hardening-heat., or, for special work, two or three heats. During the year 1911, more than 100,000 tons of carbonizing-material was sold in the United States, at an average price of probably $55 per ton. More than 85 per cent. of this material consisted of granulated bone. Within the past four years, many manufactured compounds have been placed on the market, consisting largely of some form of carbon or carbonaceous material, with or without the addition of chemicals. Steel will absorb carbon placed in contact with it at the temperature of the atmosphere. The reaction is exceedingly slow, but. increases rapidly with increasing temperature. Below * Metallurgical Engineer, The Peerless Motor Car Co.

Dec 1, 1912

The American mining industry is vigorous today because it is young. At a time when the ore deposits of central Europe, for example, were being exploited actively, those of the United States were lying practically untouched. The founding fathers of our republic were not interested in mineral wealth because they were ignorant in such matters; their preoccupations were with defence against the Indians, the clearing of the forest, and the starting of agriculture in their new domains. They had no idea of establishing a mining industry. The Indians whom the American colonists dispossessed had no mines; they used only the metal that was to be found lying on the surface of the ground. Their arrows and spears were tipped with flint, which likewise called for little digging, if any. The native copper that glacial action had torn from the lodes of the Lake Superior region and had carried into the valleys of the Ohio and Mississippi was employed in the making of earrings, bracelets, knives, and scrapers. The same useful metal was found in many other places, in Virginia and Carolina, in Vermont and New Jersey, for example, but the Indians did not know how to melt it, much less how to smelt the ore, therefore they shaped it into tools and implements by hammering. Fortunately for them the hammering of the metal caused it to harden and therefore to become serviceable for implemental use. It is doubtful if they obtained the copper by actual mining, that is, by digging or excavating; it is true we find traces of such operations in the Keweenaw .peninsula of Michigan, but we have no

Jan 1, 1932

By P. H. Royster

SOMETHING of a mystery has attached itself to the production of ferromanganese in the blast furnace. This alloy has been produced on the Continent almost continuously since 1876 and in very considerable tonnages, but little definite information concerning the practice is to he found in technical literature, and almost nothing in the way of a theory of the manganese furnace. In this country prior to 1904, bit one company had attempted its production in a serious way, and none of the operating data or other information from this company has been, or is, available to the public. In the last 5 years, as a result of the restriction of imports, a number of furnaces have been blown in on this alloy, with the result that in 1918 as many, as 18 furnaces were in blast. The majority of the men in charge of these furnaces had had little previous experience in such operations. Realizing the advantages both to the country and to the industry from a pooling of operating data and experiences, the Bureau of Mines, in the summer of 1918, undertook the collection of data from ferromanganese furnaces. Although the results of this investigation have already been reported to the companies cooperating, they may he of permanent metallurgical interest, so this paper attempts to give, briefly, the more important points brought out in the investigations. OPERATING DATA IN FERROMANGANESE PRACTICE Operating data were collected by the Bureau from 11 ferromanganese furnaces, which will be referred to throughout this paper as furnaces A, B, C, F, G, I, J, K, L, M, and P. The dimensions, of seven of the furnaces are given in Table 1. The companies from whom this infor-

Jan 2, 1919

By Blamey Stevens

It is now generally agreed that most metals have been brought to the surface of the earth by volcanic agencies. The question as to how these metals came from the volcanic matrix to the mineral deposit has been often discussed. It might be useful to give more serious consideration to the ultimate origin of the volcanic material. It is possible that some light might thus be shed on the persistent associations of some metals with certain particular kinds of rocks. For example, the very general association of gold with acid types of igneous rocks, of tin with granites or quartz-felsites, of certain types of deep-seated copper-deposits with magnesian eruptives, and so on. One interesting question is as to whether the metals brought near the surface by volcanic agencies appear here for the first time, or whether they came from the central core of the earth. The interior of the earth is, without doubt, much more highly metallic than the crust, and so the core is often thought to be the origin of many of the metals which are uncovered by man. The Differentiation Theory.—Although a great many theories bearing upon these matters have been discussed,' the only one now considered as worthy of much consideration among American geologists is the " Theory of Differentiation of Igneous Magmas."2 According to this theory, lakes of molten magma are supposed to exist very far down beneath the earth's surface. In these lakes a process of differentiation is supposed to be going on whereby the liquid magma is split up into two or more liquid phases. Each of these phases is supposed to take with it the metallic constituents for which it has the greatest affinity.

Jan 1, 1913

[The following discussion, comprising both remarks made at the Chicago meeting and contributions since forwarded to the Secretary, is based upon the following papers, presented at that meeting : "Segregation and its Consequences in Ingots of Steel and Iron," by Alexandre Pourcel, Paris, France. (See p. 105, mans. xxii.) " Microscopic Metallography," by F. Osmond, Paris, France. (See p. 243, Trans. xxii.) " Microstructure of Ingot-Iron in Cast Ingots," by Prof. A. Martens, Berlin, Germany. (See p. 37.) " Microstructure of Steel," by Albert Sauveur, South Chicago, Ill. (See p. -546, Trans. xxii.) "Farther Observations on the Relations Between the Chemical Constitution and Physical Character of Steel," by William R. Webster, Philadelphia, Pa. (See p. 113.) "The Heat-treatment of Steel," by H. M. Howe, Boston. Mass. (See p. 466.) Since all these papers were considered together, no attempt has been made to separate the discussion strictly under the several heads.] William R. Webster, Philadelphia, Pa.: I desire to say that in my first paper (Trans., xxi., 766) the actual ultimates were subtracted from the estimated ultimates, whereas in the paper submitted at this meeting the estimated ultimates are subtracted from the actual, thus giving contrary signs. The latter method corresponds with the direct effect. of low and high finishing-temperatures ; that is, a plus difference indicates low, and a minus difference high, finishing-temperature. I make this explanation to prevent confusion in comparing the two papers. Mr. Sauveur has shown that there is a close relation between the size of the grain and the ultimate strength, and also that the size of the grain depends on the temperature at which the material is finished in rolling, and on the chemical composition of the steel. I have shown that there is a close relation between the chemical

Jan 1, 1894

By Magnus Troilius

For some time I have been using with great advantage, for the purpose of determining rapidly and accurately the chemical composition of gases from Siemens producers, an apparatus arranged generally like that proposed by Prof. Eggertz; * and I now take pleasure in laying before the members of the Institute a description of the apparatus and its use, hoping that some of them may find it. of practical advantage. At the end of the paper are given some results obtained and heat calculations, with the necessary data for the same. COLLECTION OF GASES. Fig. 1. Shows the arrangement for taking a sample of gas. The funnel F, which may be made of tin plate, is made to fit the test-hole. The gas passes up through the funnel and through the rubber-tubing with the glass tube K, filled with asbestos for retaining dust,, and is drawn into the upper flask by means of water flowing from the same into the lower flask. The upper flask must be completely filled with water from the beginning, so that no air remains. When filled with gas the screw-compressors are securely fastened on, and the flask disconnected from the funnel and receiver. Quart flasks, with openings at the bottom, are very suitable, and easily obtainable. COMPOSITION OF THE GASES. The ingredients found in producer gases are: carbonic acid (CO2), oxygen (0)) ethylene (C2H4), carbonic oxide (CO), hydrogen (H), and marsh gas (CH4). The nitrogen is taken by difference. CO2,O,C2H4, and CO are determined by absorption in various liquids and by observing the resulting diminution of volume. H and CH4 are determined by combustion with oxygen. Carbonic acid.—For this gas is used a solution of 16 grams of potassium hydrate in 100 C.C. of water. 4 or 5 C.C. of this solution absorb 100 C.C. of CO2.

Jan 1, 1883

By J. B. Rather

THE use of sulfuric acid in refining illuminating oils antedates the beginning of the petroleum industry in America by many years. It was used as early as 1792 by Tower in refining "coal oil" in the British Isles, and by 1860 there were 53 refineries in the United States manufacturing "coal oil," most of them using sulfuric acid as a refining agent. Following the completion of the Drake well in 1859, many of the "coal oil" refiners began to use petroleum for manufacturing illuminating oil, and their methods and equipment were adapted so far as possible to this new raw material. The value of sulfuric acid in refining "coal oil" having been established, this reagent was immediately tried and found to be satisfactory in refining petroleum. Notwithstanding the tremendous advances in petroleum technology since that time, sulfuric acid remains today the most valuable and most widely used means for refining petroleum products. EARLY METHODS OF DISPOSAL OF ACID SLUDGE With the almost immediate expansion of the petroleum industry came the problem of disposing of the acid sludge produced in the refining operations. While in 1859, the year of the discovery of the Drake well, a patent was granted for sludge separation and separated acid concentration, most of the earlier refiners, and many of their successors, felt that separation and recovery of spent acid was uneconomical. Accordingly, many of them disposed of the sludge in any way that seemed expedient at the time. It was buried in the refinery grounds, barged and dumped at sea, run into neighboring streams, or dumped into sewers. Some optimists carted it to open pits in the hope that it would either sink into the ground or evaporate. Not so many years ago, the superintendent of an eastern refinery, who was using the open-pit method of disposal, lost a sludge cart, with horse attached, in such a pit. The horse was recovered almost immediately, but its availability for further use was reduced to zero by the loss of its hair.

Jan 1, 1928

By Albert F. Hill

The manufacture of structural shapes in steel of uniform quality, which shall command the full confidence of the engineer, is a problem in practical metallurgy which is beginning to attract much attention in this country. The progress of the past fern years in the improvement of plant and processes has placed it within the power of the steel-maker to supply a material of such chemical composition as will meet the requirements; but this solves only in part the difficulties of the constractor. It is well understood that the influence of shop manipulations is a most decisive one upon the mechanical properties of the finished product; in many cases so great, in fact, as to cause an entire transformation in the character of the material, and to render it unfit for the service for which it was intended. On the other hand, mechanical treatment is frequently resorted to as an efficient corrective of certain undesirable properties, which may be due either to chemical composition or previous manipulation. This understood and accepted, it is evident that careful investigation of the effects of mechanical treatment is fully as necessary to the successful use of steel in engineering structures, as the investigation of the influence exerted by its chemical composition. All structural material has to undergo more or less mechanical treatment, such as shearing, punching, upsetting, etc. Each of these operations produces effects which are far more marked and decisive in steel than they are in iron, and means must therefore be adopted to counteract, or at least to modify, these effects before the material is permitted to enter the structure. The fact that both shearing and punching affect the tenacity and elasticity of steel has long been recognized; bat, through more recent investigations, it has been established that these effects are purely local, and are therefore susceptible of correction by other and simpler means than annealing. The importance of this discovery to the use of steel in structures is very great. The impracticability of

Jan 1, 1883

Gentlemen:-I herewith present a report on some of the more important activities of the Institute for the year 1921. The present incumbent took. over the active management of the Secretary's office on the first of July and his, work was facilitated, while becoming acquainted with the routine of the office, by the constant and., kindly assistance of the former, Secretary, Mr. Stoughton, during the following three months, and that no interruption occurred inn its regular and smooth operation is due to him and to the Assistant Secretary, who has always been ready to give the benefit of his experience and assistance. MINING AND METALLURGY Through the efforts of President Ludlow and the generous assistance of one of our members, coupled with the excellent work of Major Barbour, MINING AND METALLURGY has, during recent months, shown constant improvement, which could not have taken place, however, had it not been, for the support given by a number of our contributing members. We have every reason to feel encouraged with respect to the quality of the publication and its cost of production. For the year 1921, the net cost of MINING AND METALLURGY was about fifty cents per member, per annum. Occasional letters are received criticizing the Board for producing this publication, but they are more than offset by letters of approval. When the, full purpose of the publication is appreciated, criticism ceases. The elimination of MINING AND METALLURGY and reversion to free distribution of all papers to all members, whether desired or not, would mean such a heavy additional expense that the number of papers would have to be much curtailed. The generous cooperation of members in sending for only such papers as they particularly desired has saved, the Institute thousands of dollars. A plan is being worked out that will materially assist in securing a prompt distribution to members of all pamphlets dealing with subjects in which they are especially interested.

Jan 2, 1922

By Theodore Swann

DURING recent years, there has been a material increase in the use of ferrophosphorus in the steel industry. It has been observed, when rolling sheets, that those made of Southern iron did not have to be rolled at as high a temperature as the others and, consequently, did not stick together. The reason was found to be the phosphorus content of Southern iron. It was therefore thought that an addition of phosphorus to sheet steel of other than Southern origin would give the same result as the use of Southern iron. At first, this addition was made by intro¬ducing phosphate rock in the blast furnace and reducing it together with the iron ore; but, because of the necessity for only small quantities of this grade of iron, the process was not satisfactory. The manufacture of ferrophosphorus was then introduced, so that additions might be made to the open-hearth furnace or ladle. Ferrophosphorus was first manufactured in the blast furnace. This method, however, can only economically produce a grade of product up to about 20 per cent. To produce a higher grade, it would be necessary to charge a larger proportion of phosphate-bearing material; and as the rate of absorption by the iron is low, there would be an increased loss of phosphorus oxides. This feature makes the production of a higher grade ferrophosphorus in the blast furnace uneconomical. The use of high-grade ferrophosphorus in the steel requires a smaller addition and involves, besides the economies in handling, an additional economy in transportation. The alloy with a higher percentage than 20 per cent. can be made only in the electric furnace. In the ordinary operation of the electric furnace in the production of ferrophosphorus, an alloy may be produced containing 26 per cent. phosphorus; this is the limit, for it does not seem possible to produce a higher phosphorus alloy even if large excesses of phosphatic materials are used. The reasons for the difficulty in raising this percentage of phosphorus are not known. The compounds Fe3P, containing 15.6 per cent., and Fe2P, containing 21.7 per cent. phosphorus, have been studied and it appears as if the alloy produced, containing percentages of

Jan 10, 1924

By E. M. Tory, P. T. Shannon

An analysis of batch and continuous thickening in terms of the movement of planes of constant concentration (i.e. continuity waves) is presented. Use of solids flux as a primary variable greatly facilitates the analysis and clarifies the relationship between batch and continuous thickening. An "ideal" slurry is defined as one whose settling rate is a function only of the local solids concentration. An analysis of continuous thickening of this ideal slurry in an ideal thickener explains many aspects of the steady — and unsteady — state behavior of real slurries, such as the main features of a thickener's "solids profile" (including the break attributed to rake action), the sudden appearance at abnormally high feed rates of a zone of constant concentration and the velocity with which it rises, and the effect of detention time at constant weight of sludge per unit area. Where deviations exist, they are explained in terms of the batch settling behavior of real slurries. The purpose of this paper is to interpret continuous thickening phenomena in terms of batch settling behavior. Both types of thickening may be considered as the process of propagating concentration changes, due to the downward movement of the solids, from the bottom of the settling vessel upward through the slurry.' These concentration changes may be either finite or infinitesimal as in the case of the propagation of a continuous concentration gradient. The slurry itself may be moving downward as in the case of continuous thickening. The downward velocity of the slurry may be such that the concentration changes being propagated up from below remain stationary relative to the thickener walls. This is the case for steady-state thickening. It seems appropriate to analyze continuous thickening in terms of the movement of planes of constant concentration. This has already been done for batch settling."3 Although our main interest is in real slurries, there are certain aspects of both types of settling which can be deduced from a theoretical analysis of highly idealized systems. To this end, an "ideal slurry" is defined as one for which the dimensionless settling rate at any point is a function only of the local solids concentration.1,2 An "ideal thickener" is one in which there is no radial variation in either the solids concentration or in the downward component of slurry velocity. The underflow outlet is a point sink. It is to be expected that the behavior of non-ideal systems will deviate in some measure from theoretical results. However, the same characteristics which cause deviations in continuous thickening should be evident in batch settling, permitting a rational explanation of the former in terms of the latter. PREDICTED RESULTS FOR AN IDEAL SLURRY IN AN IDEAL CONTINUOUS THICKENER General Theory: In continuous thickening, the downward solids flux (mass/area-time) relative to the thickener, G, results from two different

Jan 1, 1967

Taking the Long View THE present international situation has serious implications for this nation. The possibility of total war is no more appalling than the threat of making the United States permanently into an armed camp. A period of ten years under such conditions could mean a Communist victory without firing a shot-if the present trend toward statism is allowed to continue. As individual citizens and as members of the mining profession we have the power to oppose the march toward socialism. We must not adopt shortsighted policies dictated by self-interest, but must endeavor to size up the situation as a whole and act according to what will be best in the national interest. The economic picture for the metal mining industry under present emergency conditions is apparently bright. Demand for metals exceeds supply. But there is danger that fluctuating prices will bring Government regulation. Care must be exercised in our pricing policies, or the calamity of Government intervention will be inevitable. President Truman's "loophole" reference to percentage depletion early in the year caused a brief flurry of excitement, but now that the immediate threat is over the industry has lapsed into sommolence on this subject. Special tax privileges accorded the mining industry because of inherent risks should be guarded by a continuing propaganda campaign to educate Congress and the public. If this is not done we may find ourselves losing the necessary tax protection which we now possess by a capricious act of legislation. Stockpiling minerals from abroad certainly lengthens the life of our own mineral resources. The present consumer demand for the base metals indicates foreign sources of supply for stockpiling. However, this is only one facet of the problem. For strategic military reasons it is necessary that the United States have quick sources of all minerals within our national boundaries. Undeveloped mineral deposits do not meet this need so that where it is possible to encourage our own mineral development by stockpile purchases, it should be done. A need exists for an overall controlling agency that would make purchases for the stockpile according to military necessity, current metal market conditions, and so as to strengthen the mining industry. In the course of the history of the United States we have been engulfed in several wars by the necessity of protecting our economic rights abroad trading privileges-and also because of moral obligations. Disregarding the moral side, it is difficult to reconcile fighting wars to protect world freedom of trade when in peacetime we attempt to restrain such trade by tariff barriers. When it comes to accepting subsidies from the Government in one form or another it is difficult to overlook the immediate personal gains and see in the future that where the Government lays out capital it becomes a partner in the business and not a silent one. It is apparent that hope for the traditional American way of life cannot be bought without some self-sacrifice; and we cannot wait for the other fellow to start it because it is the responsibility of each individual citizen. By taking the long view our course should be apparent and not diverge sharply from our own personal benefit.

Jan 10, 1950

By Georges Caraghiaur

INTRODUCTION A small, independent mining enterprise (SIME) is an independently owned and operated business concern engaged primarily in mineral development, from the exploration to the production stage. By definition, a SIME is not dominant in its field and has no long-term financial backing. It is not a major producer of minerals, nor is it a petroleum company, a government organization or a subsidiary of such organizations. A SIME may or may not be listed on stock exchanges. The SIME is also called small miner, junior mining company, speculative mining company, and penny-stock mining company. The survival and growth of a SIME is most often controlled by an independently minded entrepreneur, who not only conceives and carries out new projects, but is materially affected by the success or failure of these projects. Usually, a SIME does not have a large or constant cash flow. Such a lack of long-term financial backing forces the SIME to meet the challenge of finding capital for its activities on a step-by-step basis. Its survival strategy is thus based on finding funds at the right time, of the right type and in the right quantities. The purpose of this paper is to show that the type of venture in which a SIME is involved affects the difficulty of raising new capital and the choice of possible sources of funds. The Small, Independent Mining Enterprise (SIME) The SIME is not a figment of the imagination of financial speculators. In Canada, there are more than 1,800 small mineral enterprises which spend on the average less than $1,000,000 per year on activity which is directed at bringing forth new mineral supply. In the United States, 64% of the non-fuel mining operations are conducted by nine or fewer men, and the coal industry is characterized by several thousand smaller independent producers, still predominantly family owned or controlled. In Chile, 80% of the mines can be classified as small mines. In the Philippines, approximately 60% of metal mining operations are classified as small mines. The SIME is actively engaged in mining all over the world, and very much so in the Pacific Rim. The Mineral Supply Process The whole process of bringing forth new mineral supply involves a dynamic sequence of activities, ranging from the initial exploration for a mineral occurrence to the production of a marketable product. A typical sequence is outlined in Figure 1. At the grass-roots exploration stage, a series of geological, geophysical and geochemical tests is aimed at locating a mineral occurrence. Especially in the early phases of such activities, the uncertainty (risk) surrounding a venture is high, since only general geological information exists on which to base a judgement of the economic viability of the venture. Such risk is attractive to few investors. As the information-gathering process continues, uncertainty diminishes. Once exploration efforts result in the discovery of a mineral occurrence, i.e. when indications of mineralization and mineable widths are obtained by drilling, there is still uncertainty concerning the extent of mineralization and the probability of having located an economic mineral deposit. The expected return on investment at such a stage may well be negative but the slight possibility of a very high positive return will make a number of financial sources available to an exploration company. At the development stage, much of the uncertainty

Jan 1, 1985

By Paul A. Farrar, Sanford Adler

The Tz-Zr system was reinvestigated using both metallographic and X-ray diffraction techniques. It mas found that titanium and zirconium are soluble in all proportions in both the a and 0 phases. The minimum in the transformation was found at 50 at. pct and 535°C. THE Ti-Zr system has previously been the subject of several investigations.1-6 A study by Hayes et al.5 using magnesium-reduced titanium and zirconium melted in graphite crucibles indicated that the system was a continuous series of solid solutions in both a and 0 phases with a minimum at approximately 545°C and 65 pct* Zr. These conclusions were substantiated by the work of Duwez4 as well as by the limited data of Craighead et al.,3 Fast,2 and deBoer.1 However, a more recent investigation of the titanium-rich region by Ence and Margolin6 indicated that the solubility of zirconium in a, titanium at 500°C is approximately 22 pct with the a + 0 field extending to approximately 47 pct Zr. Therefore in order to resolve this discrepancy the following investigation was initiated. EXPERIMENTAL PROCEDURES The alloys used in this investigation were prepared as 20- to 30-g buttons by nonconsumable electrode melting in a helium atmosphere. The starting materials were Bureau of Mines titanium BHN 71 and Foot Mineral iodide crystal bar zirconium. The titanium was premelted before the alloys were prepared to avoid excessive weight losses in the final melting. The compositions of the alloys prepared were as follows: Ti-12.0, 22.2, 29.0, 39.6, 50.0, 58.0, 72.4, 83.5. and 90.8 pct Zr. Prior to heat treatment the alloys were cold-worked 10 to 20 pct, stopping at the first signs of cracking. Specimens for heat treatment were wrapped in molybdenum sheet and annealed in argon-filled quartz capsules for the following times and temperatures: 750°C-40 days, 675°C-61 days, 600°C—109 days, 575°C-112 days, 550°C-112 days, 525°C—127 days, and 450°C —153 days. Quenching was accomplished by breaking the capsules in an iced-brine solution. The standard techniques used for polishing the specimens involved belt grinding, grinding on emery paper, polishing electrolytically, and etching with Remington "A" etch7 or "R" etch 8 Debye-Scherrer X-ray powder photograms were obtained for a number of samples using a 114.6-mm camera and CuK, radiation. Exposure times were from 19 to 23 hr. The powder samples were obtained by filing to 270 mesh size. After filing the samples were wrapped in molybdenum foil capsuled in quartz and reannealed at the temperature of original heat treatments; following the heat treatment the samples were quenched into iced brine without breaking the capsules. RESULTS AND CONCLUSIONS On the basis of the microstructural examinations of the heat-treated samples and of the X-ray diffraction data, the Ti-Zr system shown in Fig. 1 was constructed. The data indicate that a, and 0 titanium form a complete series of solid solutions with a, and ß zirconium. The minimum was found to occur at 65 pct (50 at. pct) Zr and 535°C, in excellent agreement with the earlier investigations,1-5 see Fig. 2. Typical microstructures are shown in Figs. 3 to 7. Figs. 3, 4, and 5 show the 22.2, 39.6, and 50.0 pct Zr alloys after heat treatment at 675°C for 61 days with the 22.2 pct Zr showing equiaxed a, and the 39.6 pct Zr alloy a + transformed ß, while the 50 pct Zr alloy shows only transformed B. Figs. 6 and 7 show the 29.0 and 39.6 pct Zr alloys after heat treatment for 109 days at 600°C. The 29 pct Zr alloy has an equiaxed a structure while the 39.6 pct alloy has a partially recrystallized a+ß structure. X-ray diffraction data obtained from the 50 pct Zr alloys after heat treatment at 525° and 450°C as well as from the as-cold-rolled material showed only those lineos which couid be indexed a: a titanium, good agreement with the previously published values. 2,4,5,9 Chemical analysis* of the 50 pct Zr alloy

Jan 1, 1967

By AIME AIME

AWRDED jointly by the four AW Founder Engineering Societies the John Fritz Medal is generally regarded as the most signal honor that American engineers can confer on a fellow engineer. The roll of 34 recipients contains the names of Lord Kelvin, George Westinghouse, Alexander Graham Bell, Thomas. A. Edison, George W. Goethals, Guglielmo Marconi, and Michael I. Pupin; and among members of the A.I.M.E. now living, Sir Robert A. Hadfield, Herbert Hoover, and Daniel C. Jackling. On the evening of March 1 7 the name of Paul Dyer Merica was formally added to this list of illustrious engineers when the medal was presented to him at a dinner at the Metropolitan Club in New York. The citation read. For important contributions to the development of alloys for industrial uses. Arrangements for the dinner were made by the following committee representing the four Founder Societies: R. C. Allen, George S. Davison, A. A. Potter, and J. B. Whitehead.

Jan 1, 1938

By Roscoe Bell

An economic appraisal of the western phosphate industrial potentials made between 1945 and 1948 revealed possibilities for a considerable expansion in the production of high analysis phosphate fertilizer. The most significant facts are: (1) a rapidly increasing and a much larger potential market which might be reached from the western deposits, (2) the existence of large undeveloped deposits of phosphate rock, (3) potential energy from sulphuric acid, coal, or hydroelectric power in the general vicinity of the deposits. The challenge to the mining and metallurgical engineering profession is in the economical development of phosphate mines and in improving processes for utilization of the western ores and the recovery of byproducts to make the expanded western industry satisfactorily compete with the industry in the East and South in meeting the fertilizer needs of the Midwest and Far West.

Jan 4, 1950

By Walter E. Hopper

(Wilkes-Barre Meeting, June, 1911.) I. LOCATION AND EXTENT. THE Caddo oil-field, shown in Fig. 1, is located in Caddo parish, northwestern Louisiana. The known producing territory of oil is covered by townships 19 N, 20 N, 21 N, 22 N, and ranges 15 and 16 W., shown in Fig. 2. The center of the field may be taken as Oil City, 24 miles north of Shreveport, on the Kansas City Southern railway. Shreveport is the second largest city in the State, and is the connecting point of five rail-road-lines. Drilling at the present time, however, is going on all over northern Louisiana, especially in Caddo and the neighboring parishes. II. HISTORY AND DEVELOPMENT. Natural gas escaping at the surface is found at numerous places in northwestern Louisiana. At Shreveport, the plant of the Shreveport Ice & Refrigerating Co. has been lighted by natural gas for 20 years. The well was drilled for water, but was abandoned on account of the gas. A test well, put down in 1905 near the western limits of Shreveport, was driven to 1,650 ft., and encountered indications of gas and oil at various depths, but did not succeed in finding enough to be profitable. Attention was first attracted to the Caddo field in 1895 by indications in water-wells from 40 to 60 ft. deep, in which the pressure of natural gas was noticeable. This indication of gas in a shallow well led to the drilling of the first well in the Caddo field, the old Savage Brothers & Morricell, or the Caddo Lake Oil and Pipe Line No. 1. The rig for this well was erected in May, 1904, and drilling began in June, 1904. The well was bailed Mar. 23, 1905, with a small amount of oil. It was deepened July, 1905, and converted into a "gasser " Jan. 3, 1906. It was abandoned January, 1907. In consequence of the finding of oil in the Savage well, drilling-operations were pushed with energy; and in April, 1905, four wells were drilling. Great trouble was experienced with

Apr 1, 1911