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Bill S.1431 for the creation of a Department of Natural Resources has received a propitious hearing before the Senate Committee on Government Operations. Interior Secretary Rogers C. B. Morton was one of the prominent witnesses who testified in favor. The department had been proposed, Morton said, with "the conviction that the development of all natural resources would be harmonized with the most practicable possible means to protect and preserve the environment, consistent with the social and economic needs of the Nation." Another opinion on the pro side came from Atomic Energy Commissioner Clarence E. Larson, who said that a "total picture" had become essential to the establishment of a policy for developing energy resources in the best public interest. Commissioner James T. Ramey, on the other hand, was one of the AEC dissenters. Ramey said he believed the reorganization of resource responsibilities would hinder efforts to deal with energy-environmental problems and prevent the use of AEC "expertise and facilities" to the greatest advantage. As Arnold Weber, associated director of the Office of Management and Budget, pointed out, however, retiring AEC Chairman Glenn T. Seaborg is in favor of the new department. Another supporter, and one who can cast a vote on the bill, is Sen. Frank E. Moss. Final Standards for emissions from new stationary sources will be published by the Environmental Protection Agency on October 27. The initial proposals, appearing in the Federal Register on August 17, called for limiting emissions per million Btu of heat input (maximum 2-hr average) to 0.2 lb of particulate matter, and, where solid fuel is burned, to 1.2 lb of sulfur dioxide and 0.7 lb of nitrogen dioxide. While the new rules are mainly for new plants, the EPA is also proposing them for "existing plants which are modified in such a way as to increase or alter. . . their emissions."

Jan 1, 1971

By E. W. Newman

DURING 1943 and 1944, there was an urgent need for certain grades of optical calcite (Iceland spar) for instruments for military uses. To find a supply of this material, prospecting was carried out in Montana, California and Colorado. Although some production was obtained by the work in California, the best results were from prospecting the large calcite veins of south central Montana. The bulk of the optical calcite mined during World War II has come from that area. The Bureau of Mines took an active part in the search for optical calcite in Montana. It examined most of the known calcite veins in the 70-mile distance between Wilsall, on the Shields River, and Absarokee, on the Stillwater River, and conducted exploration on several of the deposits. The Geological Survey also took an active part by mapping many of the veins. Actual mining of the calcite was performed at first by Calcite Operators, Inc., and later by the Metals Reserve Co., through an agent. A sorting plant was established at Clyde Park, where custom material could be sold. These activities stimulated mining by private operators. To be suitable for military uses, the calcite mined had to meet rigid specifications as to both size and quality. Individual crystals had to be clear and transparent and if in the form of rhombs had to measure at least 7/8 in. on each edge. Some color and a few inclusions in the calcite were allowable, but material with incipient or developed cleavages, or showing twinning other than parallel to the base, was unacceptable. HISTORY OF DEPOSITS The existence of large veins of calcite in south central Montana has long been known, and for many years the farmers of this region have used the common vein calcite for producing grit for chicken feed. According to reports, the first optical calcite produced from Montana came from the Cartwright deposit near Greycliff,1 but until recently the mining of optical calcite in Montana has been limited to spasmodic searching for small crystals suitable for making nicol prisms for saccharimeters and microscopes, or for mineral specimens. The possible need of substantial amounts of optical calcite for military uses began to appear late in 1942 and early in 1943, therefore the Polaroid company began searching for a source of supply in Montana and California. Work on the Wade property near Clyde Park was started on a small scale in the fall of 1942, by A. H. Hansen, of Clyde Park. During the winter and spring of 1943, a modest quantity of optical calcite was mined and shipped to the Polaroid Corporation, Cambridge, Mass. Most of this was produced from the "Hansen vug," which was found close to the surface. Early in the summer of 1943, mining on the Wade property was undertaken by Calcite Operators, Inc., a company organized for mining optical calcite from the Montana and California deposits. This com-

Jan 1, 1945

By Frank Firmstone

THE indicator cards shown herewith were taken by the writer in June, 1877, from the water-pressure blowing engine of the Longdale Iron Co., at Lucy Selina Furnace, Longdale, Virginia. A description of this engine with figures, and some indicator cards, was published by Washington Jones, Esq., Superintendent of the I. P. Morris Co.,* in the Journal of the Franklin Institute for May, 1877, to which those desiring a full account are referred, but for convenience the principal dimensions, etc., are given below. The machine consists of a pair of horizontal directacting blowing engines, connected at right angles to a common fly-wheel shaft. The blowing cylinders are 4 ft. diameter by 5 ft. stroke; the water cylinders were 18 in. diameter by 5 ft. stroke as built. Both water and blowing cylinders are double acting. The water valves are balanced piston valves, 18 in. diameter, moved directly by eccentrics on the fly-wheel- shaft. Great care was taken to have the areas of the ports and passages at least equal to the area of the working piston. The engine is set about 14 ft. above the tail-race, and the * The engine was built by the I. P. Morris Go., from drawings made by Messrs. Tuws and Hartman.

Jan 1, 1879

By Philip S. Mathews

THE tremendous stimulus given to the mining industry by the gold and silver policy of the present administration has found the capital market for mines ill prepared to afford practical means of financing. Particularly has this been true of the host of abandoned high-cost producers and prospects which increased gold and silver prices have made potentially profitable. In a comparatively short time, experience has demonstrated abundantly that valuable properties have frequently failed to secure capital, while questionable properties have drawn to themselves and their promoters more of the public moneys than their prospects justify. Singularly enough the fault is usually attributable to faulty financing. Discussion and study of this problem are vital to the industry.

Jan 1, 1936

By AIME AIME

THE complete list of papers for the meeting of the Petroleum Division that is to be held" at Tulsa,' Thursday and Friday, Oct. 3 and 4,, with assignment to individual sessions is given below. THURSDAY MORNING First Session Well Spacing Theory of Well Spacing-By W. P. Haseman. Discussion by S. C. Herold, J. R. Suman and Lester C. Uren. Well Spacing in the Long Beach Field, California-By - Stender Sweeney. Discussion by C. H. McNeese; R. R Brandenthaler and W. V. Vietti. Well Spacing in the Bradford Field, Pennsylvania-By Paul D. Torrey. Discussion by A. F. Melcher, R. M.. Haskell, J. B. Umpleby and J. B. Newby. Results of Different Well Spacing in the Salt Creek Field, Wyoming-By Fred E. Wood. Discussion by Sam Grinsfelder and Kenneth B. Knowles.

Jan 1, 1929

By E. Kendall Cork

The traditional financial objective for a single mine company has been to operate as frugally as possible and to pay out most of the earnings as dividends. If the business is cyclical (as it is for most metals) the dividends might fluctuate quite widely. When the mine is exhausted the company disappears. This is still quite a viable strategy for a single mine company. It is not however a viable strategy for the world as a whole. The mining industry is built by mine development companies who can mobilize the people and capital to bring new mines into production. Their skills must include marketing, engineering, finance and other politics. It is very rare for a property to be brought in without the support of a major company that can provide all these services. The exceptions will usually have some other form of big brother support, for example the U.S. government uranium contracts at guaranteed generous prices. The mine development company will seek as a minimum to perpetuate itself by developing new mines in order to replace those which are running out. The more common and more ambitious objective is to grow -- that is to add to its ore reserves and current production by developing more new mines. The financial objectives for that company are very different. Obviously if all the earnings were paid out in dividends there would be nothing left to work with. The first financial policy then is to spend an appropriate amount on exploration for new properties. The next is to retain enough of the earnings to provide the capital for new projects at least sufficient for the equity. There is no magic formula as to what proportion of earnings should properly be distributed as dividends by a growth-oriented mine development company. As a rough rule of thumb distributing half or more will probably leave too little to work on and 30% or so is probably a good balance. However the circumstances differ widely from company to company. It may be useful to set an objective for the rate of growth of a company's earnings. Some have picked rates such as 15% per annum compounded. Others have set a target in real terms which might appear as 10 or 11% plus inflation. Obviously the arithmetic of compound interest is very attractive; however in practice there is much variation. Indeed current returns from existing operations swing widely with the business cycle and there is no assurance that economic new properties will be found according to someone's arbitrary time schedule. For example, Western Mining Corporation Limited in Australia explored for 30 years with little to show for it, but then found the great Australian nickel deposits and more recently the huge Roxby Downs copper. That long dry spell could not have fitted anyone's arbitrary calendar of growth and yet they would not have found such orebodies without that long period of effort. Should they have abandoned the search? Once a new property has been found or acquired there has to be a threshold rate of return on the new capital to be invested against which to evaluate the property's economics. Conventionally this seems to be 15% after tax, a number common in other heavy industries as well. In some cases it is expressed as a lower number plus allowance for inflation. Discounted cash flow analysis is a very useful tool but it does not make the decision. In the end a "go" decision depends on judgment of many factors some of which are numbers used in the DCF calculation whose credibility must be examined. It is curious how frequently investment proposals come in with the rates of return very close to 15%. The project advocates know that a number much less than 15% will not fly and that a number much more is not necessary. With much higher nominal and real interest rates of recent years, even though before tax, logic suggests that the hurdle rate should also rise. The power of compound interest is so great that 20% is very hard to achieve in any cash flow projection but 18% may be a sensible yard - stick. Once again it is remarkable how many project proposals come in with an 18% return. On the record the mining industry as a whole has not been overly restrictive in choosing its hurdle rates of return. This is shown by the abundance of metals in recent years and the failure of metal prices to keep up with inflation. All of the foregoing is standard text book stuff.

Jan 1, 1985

By Leon McCulloch

WHEN clean iron and metallic zinc dust, protected from the air, are heated below the melting point of zinc, the iron takes on a coating that has excellent protective value. This coating is a brittle alloy of zinc and iron, and the process is called sherardizing. Although the zinc particles are covered with oxide and cannot touch the iron, an extremely small amount of the zinc vaporizes and the vapor, reaching the iron, alloys with it. Other zinc then vaporizes to replace that which has been removed from the atmosphere. This process continues indefinitely at a decreasing rate, for the coating already formed permits zinc to diffuse through-it to combine with the iron beneath. In this way, the coating grows outward from the surface of the iron, as the bark grows from a tree. The method of growth was clearly seen while sherardizing small cubes of cast iron, at about 450° C., in a small glass-stoppered bottle enclosed in a rotating drum. The dust contained about 3 per cent. iron, which prevented caking, and coatings 1/2 in. thick were grown in a few hours. After a heavy layer had been formed, the cubes were again: treated for a shorter time. The layer last formed was seen to lie next to the iron, instead of at the outer surface, showing that the growth was from the surface of the iron outward. The coatings split at the edges and corners, leaving the iron exposed there. Flakes of graphite from the iron were lifted upward and embedded in the coatings. The composition of sherardized coatings varies from the outer surface inward, as would be expected from the mode of growth. That is, the iron content increases slowly at first, then more rapidly as the iron is approached. At the surface the least amount of iron possible is 6 per cent., as the experiments described below have shown.

Jan 2, 1922

By Petter Östberg

Having brought with me to this meeting a couple of "Mitis'' wrought-iron castings, I have found that they attracted a great deal of attention from steel manufacturers, and especially from those experienced in making castings, among whom some have said that they felt inclined to "unhesitatingly dcclare their manufacture an impossibility," if they had not seen the samples. The consequent demand for explanation of the method of manufacture has been SO great that I accept with pleasure the request by the President to address the meeting on the subject. My object in this address shall be only to explain the main features of the manufacture, referring those who take more interest in the matter to Mr. Th. Nordenfelt's paper, read before the British Iron and Steel Institute, reprinted in many American papers, and containing both a historical sketch of the inventions and many interesting details. As the manufacture of castings from steel by others is, at least to some extent, a success, I shall, in my explanations hereafter, refer to wronght-iron, although our mode of manufacture is equally applicable, with corresponding advantage, to steel of any temper. The successful manufacture of castings depends upon several very important matters, besides the necessary skill of the workman. You must have a suitable metal as raw material; you must have an eacient and suitable furnace for smelting, so as not to injure the metal; you must be able to handle the metal in a suitable way, from the time it is ready in the furnace until it is poured into the moulds; you must have a suitable moulding material. I claim that in every one of these different branches we have made great

Jan 1, 1886

We have received from L. S. Cates, the following translation, by S. W. Mudd, of early mining methods in India: In Herodotus one finds a description how Darius by aid of his good horse and his good groom Oebares got himself the Kingdom of the Per-sians. He then set up in Persia twenty satrapies assigning to each a governor and fixing the tribute which was to be paid to him by the several nations. The following description of the method of getting the gold demanded of the Indians as tribute is copied directly from Book III Thalia, paragraphs 94 to 105 omitting the diversions of Herodotus which in one case consisted of a lapse of two pages following a semicolon before the author returned to the subject. The Indians, who are more numerous than any other nation with which we are acquainted paid a tribute exceeding that off every other people, to wit, three hundred and sixty talents of gold-dust. The way in which the Indians get the plentiful supply of gold, which enables then to furnish year by year so vast an amount of gold-dust to the King, is the following: Eastward of India lies a tract which is entirely sand. Here, in this desert, there live amid the sand great ants, in size somewhat less than clogs, but bigger than foxes. The Persian king has a number of them, which have been caught by the hunters in the land whereof we are speaking. These ants make their dwellings under ground, and like the Greek ants, which they very much resemble in shape, throw up sand-heaps as they burrow. Now the sand which they throw up is full of gold. The Indians, when they go into the desert to collect this sand, take three camels and harness them together, a female in the middle and a male on either side, in a leading-rein. The rider sits on the female, and they are particular to choose for the purpose one that has just dropped . her young; for their female camels can run as fast as horses, while they bear burdens very much better.

Jan 12, 1919

By R. A. Greenkorn, R. C. Smith

Hele-Shaw cells are used to model creeping flow through porous media (where Darcy&apos;s law is valid). The effects of inertia on flow about obstructions in a Hele-Shaw cell can be calculated by a perturbation method if one can determine a solution to Laplace&apos;s equation. Results of a computer solution for flow about circular, square and elliptical obstructions are presented. These results show that or a modified Reynolds number of less than I, the inertia terms are small; and for values of less than 3, the average streamline predicts the ideal flow. Therefore, the analogy might be used for studying flow in porous media up to a modified Reynolds number of at least 3. INTRODUCTION The nature of fluid flow in porous media is of interest in the fields of soil mechanics, ground water flow, petroleum production, filtration and flow in packed beds. Because it is very difficult to study the phenomenological behavior of flow in porous media, homologs and analogs are used to study flow characteristics. A Hele-Shaw model, made of two closely spaced plates - usually glass — is often used as an analogy to two-dimensional flow in porous media. Hele-Shaw2 showed experimentally that the streamline configuration for creeping flow around an obstacle located between two closely spaced parallel plates is the same as for two-dimensional, ideal flow about the same obstacle. Stokes7 verified these observations mathematically. The usual equation of motion for flow in porous media is Darcy&apos;s law. The form of the mathematical statement of Darcy&apos;s law is identical, within a multiplicative constant, to the expression for the average velocity over the plate gap in the plane of a Hele-Shaw model. These models may be used to describe flow in both homogeneous and heterogeneous porous media. In the mathematical proof of the Hele-Shaw analogy it is assumed that the convective terms in the Navier-Stokes equations are negligible and that the equations of motion degenerate to Laplace&apos;s equation, with pressure the dependent variable. Whenever a Hele-Shaw model is used as an analogy to flow in porous media, .the validity of this assumption is in question. Riegels5 showed that if convection is not neglected, the velocity distribution around a cylindrical obstruction in the flow field depends on a Reynolds number, the plate spacing, and a dimension characteristic of the obstacle. Riegels&apos; solution, a perturbation solution, uses the boundary condition that the flow rate into the obstacle averaged over the plate gap at any point on the obstacle is zero. The method requires that a solution to Poisson&apos;s equation for the perturbation pressure be found. Riegels evaluated this solution for the case of the cylindrical obstruction. His method may be simplified by eliminating the need for solving Poisson&apos;s equation for the perturbation pressure. Instead, an analytic expression for the perturbation pressure gradient is obtained (valid for arbitrary shapes) and used to eliminate pressure from the equations for the perturbation velocities. The results show, for symmetrical shapes, that if NRe < 1, the convective acceleration terms are small, and that the average velocities represent ideal flow up to at least NRe = 3, where: L is a characteristic dimension of the obstacle perpendicular to flow, b is the plate spacing, u is viscosity, v, is velocity of approach and p is density. THEORY* Incompressible fluid flow through a Hele-Shaw model and a porous medium are analogous because the equations for the average velocity components in two-dimensional flow are identical if:

Jan 1, 1970

By A. Grant Elliot, H. W. Lavendel

qualitative picture has been developed to describe the oxidation behavior of TaSi2-coated tantalum and CbSi2-coated columbium. These systems have a significantly lower inherent oxidation resistance than MoSi2-coated molybdenum does. This stems primarily from the fact that Ta2O5 and Cb2O5 are nearly as stable thermodynamically as SiO2, whereas MoO2 or Moos are not. Further, diffusion of silicon in the Ta- and Cb-Si system is considerably slower than in the Mo-Si system. These ,factors prohibit the mechanism of selective oxidation of- silicon which accounts for the oxidation resistance 01- MoSi2-coated molybdenum. The silicide can be stabilized by adding suitable Modifiers which increase the thermodynamic stability of the silicate formed during oxidation. Modifiers, such as aluminum, can be inroduced into solid solution in the coating. in controlled amounts through proper selection of the source in the pack cementation process of coating fov~rzatiorz. Addition of aluminum to TaSi2, coatings on tantalum was effective in moderately increasing the oxidation resistance. EXTENSIVE experimental work and analysis have established the nature of the oxidation behavior exhibited by MoSi2- and MoSi2 -coated molybdenum-base alloys, and defined the conditions for maximum protection against oxidation of the substrate.&apos;-* The oxidation resistance of MoSi2 in the temperature-pressure range of 1100°C-PO2 > 10-5 atm to 1900°C— PO2 > 10-1 atm is due to the formation at the surface of a continuous film of SiO2 which results from selective oxidation of silicon. Under the prevailing kinetic conditions, this film is stable toward the molybdenum silicide with which it comes in contact. Initially molybdenum oxidizes also, but it forms volatile species. SiO2, however, nucleates and grows as a condensed phase. Once a continuous film of SiO2 has formed, the oxidation rate falls to that observed for the oxidation of pure silicon indicative of diffusion through the oxide film as the rate-controlling mechanism. This oxidation behavior is of course highly dependent upon temperature and oxygen pressure. Bartlett and Gage13 and Bartlett, McCamont, and Gagelb define precisely this dependence in terms of the oxygen partial pressures and silicon diffusivities required to support a stable SiO2 film. At low temperatures (near 500°C—the "pest" region) silicon diffuses too slowly to be selectively oxidized. Hence, molybdenum and silicon oxidize readily in proportion to their stoi- chiometry. At high temperatures and low pressure, SiOz dissociates to form volatile SiO(g), and a protective film cannot be maintained. Application of the MoSiz/Mo system is limited to temperatures below 1900oC, the eutectic between MoSi, and MO5Si3.5 The oxidation behavior of MoSi2-coated molybdenum is essentially the same as that outlined above with the exception that the MoSi2 is not in equilibrium with the molybdenum substrate. At the temperatures under consideration silicon will diffuse rapidly into the molybdenum eventually converting the coating to MosSi3.4 The rate constant for subsequent decomposition of Mo5Si3 into Mo3Si plus silicon, and/or the diffusivity of silicon through Mo3Si then becomes low enough to allow active oxidation of both molybdenum and silicon with subsequent degradation of the specimen. A stable silica film can be formed but at temperatures and/or oxygen partial pressures higher than those required with MoSi2 present as a source of si1icon.l, 4 Because of the similarity between the silicides of molybdenum and those of columbium and tantalum one would expect similar oxidation behavior for coatings in the respective systems. This is not entirely the case, however, as shown by the experimental results reported herein. Regarding tantalum and columbium disilicide coatings on tantalum and columbium substrates, respectively, the oxygen arriving at the surface of the coating partitions itself nearly equally between the metal and the silicon, and a two-phase oxide layer (Me2O5 plus SiO2) is always formed. The diffusion of silicon in the tantalum and columbium silicides is relatively slow, compared to that in the molybdenum silicides, which further enhances this equipartitioning of oxygen. Thickening of the coating during service by inward diffusion of silicon into the substrate is correspondingly slow, and the effective thickness of the coating at the roots of cracks and defects is only slightly changed providing high probability for premature coating failure. Furthermore, the SiO2 glass that is generated is not thermodynamically stable with respect to the coating. The metal silicide tends to reduce the SiO2 liberating either free silicon or SiO. The situation can be improved by suitably modifying the coating such that the stability of the protective glass which is generated during service is increased. Thus, selective oxidation of silicon and the modifying agent will occur, and the silicide coating will not tend to reduce the oxide layer. Modifying agents can be introduced into the coating by the pack cementation process. Using sources containing the modifier at controlled chemical potentials allows control of the coating composition. Partially substituting aluminum for silicon in TaSi2 coatings by forming a Ta(Si,Al)2 solid solution was effective in moderately increasing the oxidation protection.

Jan 1, 1968

By Clyde Williams

IN this war as in no former one, the use of metals has been the major factor governing success. For building new plants, new transport facilities whether by land, sea, or air, for our mechanized army, and for nearly all weapons, iron and steel has provided the basic material. Being the world leader in iron and steel production in peacetime, we soon adapted plants to production for war. Starting with a production of 66,000,000 tons of steel ingots in 1940 from a rated capacity of 80,000,000 tons which only could be reached by straining every productive device available, our industry expanded to 86,000,000 tons in 1942, and ultimately to 96,000,000 tons. To do so required expansion of every unit operation including mining, rail and water transportation, blast-furnace and steelmaking facilities, and rolling mills. New plants not only had to be built in record time but more output for each operation was essential. This performance required skillful operation and engineering techniques and also a better understanding of the physics and chemistry underlying such complex operations as the working of a big blast furnace. A vastly increased pig iron production made possible the great output of steel by an industry that had depended on scrap for its basic raw material even though sufficient scrap was unavailable. This was done by conversion of pig iron in the Bessemer either into steel or into a low-carbon product that was subsequently used in place of scrap in the open¬hearth steel furnace. Furthermore, by duplexing from the open-hearth to the electric furnace, and the construction of many new electric furnaces, our output of electric-furnace alloy steel was greatly increased. Moreover, techniques were developed by which alloy steel could be made in the open hearth with the result that our production of alloy steel reached the fantastic figure of 15,000,000 tons a year.

Jan 1, 1945

By R. R. Webster, H. T. Clark

The side-blown converter has been investigated as a possible commercial process for the production of low nitrogen steel. During this work, two converters of 3-ton and 22-ton capacity were operated on a pilot plant basis for a total of 214 heats. The steel made in these converters was low in nitrogen and possessed good cold working properties. Some problems of converter operation remain to be solved. IN plants operating with a high iron capacity, sev-eral different refining methods are used in the conversion of the molten pig iron to steel. These include various ore practices in stationary and tilting open-hearths, the duplex process employing the Bessemer converter and open-hearth, and the Bessemer process. At J&L, a considerable part of the iron produced is handled by the Bessemer process, either alone or in conjunction with duplexing, and therefore an appreciable portion of the steelmaking research effort has centered about the method. This paper covers research work on the development of the side-blow converter for the commercial production of low nitrogen ingots and includes descriptions of the operation of a 3-ton and a 22-ton experimental converter at the Aliquippa Works. The refining of iron to produce steel requires the removal of a large portion of the carbon and silicon and the control of manganese, phosphorus and sulphur which are present in the iron in varying amounts. The first large-scale means of refining iron was the acid Bessemer process which was brought into use almost 100 yr ago. This method, using compressed air as the refining medium, accomplishes substantially complete removal of carbon, manganese and silicon. Phosphorus and sulphur are not affected but, by choice of an iron composition sufficiently low in these elements, a commercial product can be produced. Since the process will handle large tonnages rapidly, operates without external fuel and with a minimum of additional equipment, it quickly became the major tool in the early expansion of the steel industry. Later, the basic open-hearth process, by affording control of phosphorus and sulphur and by consuming the large quantities of steel scrap that were becoming available, forced the acid Bessemer process into a secondary position in the industry. During the past two decades the demand for steel to be used in cold forming and drawing operations has gradually increased. Bessemer steel, because of its work hardening and aging characteristics, is not as suitable for these applications as basic open-hearth steel, consequently the decline of the process was accelerated. More recently, because of changing economic conditions, this long range trend appears to have been arrested or perhaps reversed. Ingot production data for recent years furnishes only an incomplete picture of the importance of the converter in the American steel industry; open-hearth furnaces utilize large tonnages of blown metal for which no published statistics are available. Metallurgical Aspects The fundamental difference between Bessemer and open-hearth steels apparently lies not in the method of manufacture but, rather, in the differences in chemical composition of the two steels. It is further believed that the principal features distinguishing Bessemer from open-hearth steel are the higher nitrogen and phosphorus contents of the former. Evidence supporting this position is supplied by tests on laboratory induction furnace heats that were made to contain varying amounts of phosphorus and nitrogen but were otherwise similar to normal low carbon silicon-killed steels. Fig. 1, 2 and 3, summarizing the test results, are taken from G. H. Enzian&apos;s paper titled, "Some Effects of Phosphorus and Nitrogen on the Properties of Low Carbon Steels."&apos; Fig. l indicates that phosphorus has a marked effect on the cold work embrittlement of steel as shown by the work brittleness test of Graham and Work.&apos; In the low nitrogen steels, which as a group have the better cold working properties, the effect of phosphorus variations is the more pronounced.

Jan 1, 1951

By C. W. Dunham

FROM the primary gyratory crushing plant, described in MacLeod&apos;s article, ore is delivered to a large storage or surge bin from which it is carried by two transverse conveyors to the secondary crushing plant. The bin has a useful drawoff of about 13,000 tons, this being slightly over one half of the initial daily capacity of the Morenci Reduction Works. This arrangement provides sufficient storage to permit intermittent operation of the primary and secondary crushing plants without too close a coordination between the two.

Jan 1, 1942

By G. K. Zaharlev

With a productive output growing at an annual rate of 8%, the Soviet mining industry should emerge as the world&apos;s leader in total mineral output during the 1980&apos;s. (The Soviet Union&apos;s share in the world&apos;s total mineral output in 1973 was estimated at 22 to 23%.) According to estimates by Soviet mining experts, the mineral potential of the Soviet Union will sustain the current 8% annual growth rate in the future.

Jan 12, 1974

By John W. Cahn

The spinodal has long been regarded as a limit beyond which a homogeneous phase could no longer be metastable. But only recently has it become apparent that a phase beyond the spinodal would decompose by simple diffusional clustering mechanism quite different from the nucleation and growth mechanisms encountered for metastable phases. The theory of spinodal decomposition, which is based on the diffusion equation modified by thermodynamic requirements , is phenomenological, and each parameter can be measured by independent thermodynamic or diffusion experiments. The details of the theory have been carefully verified in a number of simple systems. It appears that the spinodal mechanism is commonly encountered in clustering reactions in solids and glasses. HISTORICAL INTRODUCTION The understanding of the earliest stages of precipitation in alloys has been the subject of three prior Institute of Metals Lectures. In 1932 Paul ~erica&apos; reviewed the puzzling evidence that hardening of duralumin is completed before precipitation of CuAlz takes place and suggested that hardening occurs when the copper atoms "assemble in random groups on lattice positions of the duralumin, not of the CuAlz lattice". He called these random groups knots. This modification of his dispersion hardening theory seemed to fit all the facts, but Merica worried that the required diffusion "is just the reverse of what we deem normal; although quite spontaneous, it proceeds uphill, if you please". The reality of Merica&apos;s knots was quickly confirmed by Guinier&apos;s&apos; and preston&apos;s3 X-ray work and these knots are today known as G.P. zones in their honor. Theoretical justification for uphill diffusion was also quickly provided by Becker and Dehlinger~ who noted that the diffusion coefficient could be negative in certain regions of phase diagrams. The boundaries of such regions could be described by a 90-year-old thermodynamic concept first described by ~ibbs&apos; in 1877 as a limit of metastability for fluid phases, which by 1890 had received the name spinodal (see Appendix A). Spinodal in fluids is as old as nucleation theory. Both appear for the first time in the same paper by Gibbs who called the spinodal the limit of metastability. For the first 50 years, nucleation theory was forgotten and the spinodal was extensively treated in every good thermodynamics textbook.81Q The idea was simple and logical and it was accepted as part of a rigorous thermodynamic development of metastable phases, and for a while it was extensively investigated theoretically.

Jan 1, 1969

(Members are urged to send in for this column any notes of interest concerning themselves or their fellow-members.) Members who registered at Institute headquarters during July and August : R. H. Sweetser, Columbus, Ohio. C. R. Hill, New York, N. Y. Raymond Brooks, Goldfield, Nev. H. A. Morrison, Candor, N. C. Edward M. Shepard, Springfield, Mo. Frederick J. Patchell, Washington, D. C. Rudolf Gahl, Clifton, Ariz. Walter F. Pyne, New York, N. Y. Edmund von Maltitz, Pittsburg, Pa. Harvey B. Small, Mangangue, Colombia, S. A. M. K. Rodgers, Seattle, Wash. M. B. Cohen, Miami, Ariz. J. F. Erdlets, Jr., New York, N. Y. A. P. Watt, Newark, N. J. D. H. Ladd, Houghton, Mich. H. H. Stoek, Urbana, Ill. Roy F. Cornell, Santa Cruz, Cal. D. W. Brunton, Denver, Colo. W. B. Foote, Geneva, N. Y. C. S. Robinson, Youngstown, O. H. Sjogren, Stockholm, Sweden.

Jan 9, 1913

A new $18-million hydrometallurgical ore treatment facility for the recovery of molybdenum oxide was dedicated at Climax, Colo., on November 19 by Climax Molybdenum Co., division of AMAX. The Company has been producing molybdenum from molybdenite (MoS2) ores since 1918. Now oxide values, formerly lost in the sulfide flotation plant tailing are to be processed to yield about 3 million Ib per year of metal. In 1965, Climax produced about 50% of world molybdenum from sulfide ore. This ore is mined at the rate of 42,000 tpd. The annual production of concentrate is 100 million lb containing 90% to 92% MoS2, or about 50 million lb of metal. As only a relatively small portion of the total Climax production is sufficiently enriched in oxide molybdenum to process through the new plant, 5700 tpd of selected ore containing 1.5 lb of Mo per ton is now treated by the new process.

Jan 12, 1966

By R. C. Ellman

In the United States, the consumption of lignite and subbituminous coals is increasing. A variety of energy-oriented companies have leased large blocks of reserves, new large power plants are in operation and being constructed, and new producing mines are being developed. The Bureau of Mines has maintained an active interest in the utilization of low-rank coals for many years. In 1951, with the completion of the Bureau&apos;s Grand Forks Coal Research Laboratory, an organizational unit was established for studies in lignite preparation. Since that time, numerous investigations have been completed. This research has dealt almost exclusively with lignite, but since subbituminous coals have many similar characteristics, the findings can often be applied to both types of coal.

Jan 1, 1970

By Robert L. Clayton, Arthur Baker

Two massive sulfide zinc-copper ore bodies are in quartz-sericite schist (probably formed by regional metamorphism of sediments) and andesite of the Precambrian Yavapai Series, on opposite sides of a large rhyolite mass. The Copper Queen ore body is conformable with bedding of its schist host rock, but the Old Dick ore body probably crosscuts the strata. A lens of low-grade mineralization in chlorite schist, associated with the Old Dick ore body, crosscuts through 150 feet of strata. The ore bodies are almost entirely enclosed by premineral faults with less than 150 feet of displacement. The minerals of the ores are pyrite, sphalerite, and chalcopyrite, with minor arsenopyrite and galena and small amounts of intimately associated chlorite, sericite, and calcite. Old Dick sphalerite-chalcopyrite intergrowths have mutual boundaries, and sphalerite grains contain abundant exsolved chalcopyrite. Copper Queen sphalerite-chalcopyrite intergrowths have extremely ragged boundaries, the sphalerite contains no exsolved chalcopyrite, and the ore overall has a schistose texture. The pre-mineral fault on the hanging wall of the Copper Queen ore body has had 100 feet of post-mineral displacement. Wall rocks of the Old Dick ore body locally have been sericitized. Andesite and quartz-sericite schists for at least several hundred feet around both ore bodies have been chloritized erratically and contain traces of copper.

Jan 1, 1968