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By Henry Howe

THE brilliant and very original matter in Professor Jeffries' discussion ? should rank not only as an independent paper, but as a most important one. In particular, the explanation which it gives of the remarkable Sauveur phenomenon, over which so many of us have puzzled long and hard, is so clear, complete, and cogent as to go far toward establishing Professor Jeffries' hypothesis. The very features of Professor Sauveur's photographs which fit this hypothesis so exactly are reproduced in Chappell's photographs of steel coarsened under somewhat different conditions. 1 The ideas developed by these discoveries are so novel that conven- ience of language seems to call for new conventional terms for expressing them. In, what follows here I propose certain terms for this end, for criticism and improvement, and I attempt to generalize from Professor Jeffries' hypotheses. Generally speaking, a given set of grains which undergo no growth in the cold will, when the temperature is raised progressively, start to grow on reaching a certain temperature, and will continue growing at all higher temperatures. The "germinative" temperature is that at which growth begins, quite as the conditions which cause a seed to grow are "germinative." We have then. an inert temperature range below the germinative temperature, and a growth range above it, the germinative temperature being the limit between these two ranges. So, too, a germinant grain is one which is at its germinative temperature, and hence beginning to grow, while inert grains are those below their own germinative temperature, and the term "growing grains" includes those which are germinant and those which are above their germinative temperature. These last could be called "supergerminant" if the distinction should be needed.

Jan 12, 1916

By I. J. Gardescu

The production of petroleum in Rumania in 1932 totaled 52,560,000 bbl., an increase of 6.8 per cent over 1931. The average daily production rose from 123,000 bbl. at the beginning of the year to 173,000 bbl. at the end of the year, the production in the Gura-Ocnitzei field rising from 38,800 to 80,700 bbl. per day. This increase was due to competitive development during which time the percentage of total production of the various operating companies remained practically unchanged. Chief producers were: Concordia, 30.3 per cent; Unirea, 21.6; Romano-Americana, 13.5; Steaua Romana, 8.3. Boldesti, where production of the previous year was practically doubled, would have produced far greater quantities were it not for the fact that both Astra Romana and Romano-Americana curtailed drilling operations. Of the total daily production of 21,800 bbl. a day, the Astra Romana, Steaua Romana and Romana Americana, produced respectively 67, 25 and 8 per cent. The Moreni field showed a sudden drop in production from the preceding year, due primarily to reduced drilling activities. Its production of only 21,000 bbl. a day removes it from first position for the first time in many years. All the other fields showed a decrease in production, except Ochiuri, 3 miles west of Gura-Ocnitzei, and Ceptura, 12 miles east of Boldesti. Drilling1 During the first nine months of 1932, 116 wells were completed, 8 of which were dry holes. The Meotian (lower Pliocene) is the producing horizon in 73, the Dacian (upper Pliocene) in 31, and the Oligocene in 4 of the completed wells. Three of the Oligocene wells were drilled in the Bacau district and one at Grausor, near Campina. In addition, 47 wells were drilling on Oct. 1,1932. Of the total completions and drilling wells, 92 per cent employed rotary for a footage of 98.5 per cent of the total drilled. Power for rotary drilling was furnished to 105 wells by steam, to 38 by electricity, and to one by gasoline.

Jan 1, 1933

By I. J. Lin

Surfactants are classified according to the size and strength of the hydrophilic and lipophilic groups of the molecule. The balance of these two opposing groups is known as the hydrophile-lipophile balance or HLB. According to this definition, a lipophilic surface-active agent is assigned a low HLB number and a hydrophilic one-a high one. The HLB value is obtained as follows, on the basis of known group values defined empirically by Davies' and listed in [Table 1:]

Jan 1, 1972

By C. D. Woodward

ThE subject of elcctric signals for the despatching of mining cagey through shafts has received cousiderable attention recently from various mining companies. The Anaconda Copper Mining Co. has found it necessary to develop a system that is rcliable, safe and simple in operation, and easy to repair. The movement of all mine cages or skips is under the direction of a station tender, who rides on the cages when men or supplies are being lowered or raised; when ore is hoisted, he is stationed at a skip pocket for loading and despatching the skips. For the station tender's use, two signal systems are installed in cach hoisting compartment, and he is the only employee authorized to use them. One system is known as the "AC " or station bells, as it is operated from the 110-volt, 60-cycle, power service; the other system, called the "DC" or shaft bells, takes its energy from closed-circuit primary batteries. As a supplemcnt to the two main signals, a buzzer system is installed The general arrangement is similar to the main signal, except that there is a mine buzzer at each station. When a signal switch connected into the buzzer system is pulled down, all buzzers arc operated, thus notifying the station tender that he is wanted at seine particular level. Placed on the station posts, and within easy reach of the men on the cages are the signal pull switches for the main signals. The station, or "AC," pull switches are furnished with a short rope as shown in Fig. I, while the shaft, or "DC," pull switches are equipped with ropes that extend down the shaft past the next station. To avoid all confusion in the use of the three signal systems, a standard arrangement has been adopted in all mines for the location of the pull switches. Fig 2 illustrates the position of the pull switch at the various mine stations for the main signal systems, but it does not show the buzzer pull switch; this is fixed to the roof timbers about 25 ft. back from the shaft. If the skip pockets are a considerable distance below the station, a pull switch for each main shaft compartment is connected to the "AC" system and placed at this point. However, if the distance is short, a light cord is attached to the station pull switches and dropped down to the skip pocket.

Jan 1, 1923

By C. D. Woodward

ThE subject of elcctric signals for the despatching of mining cagey through shafts has received cousiderable attention recently from various mining companies. The Anaconda Copper Mining Co. has found it necessary to develop a system that is rcliable, safe and simple in operation, and easy to repair. The movement of all mine cages or skips is under the direction of a station tender, who rides on the cages when men or supplies are being lowered or raised; when ore is hoisted, he is stationed at a skip pocket for loading and despatching the skips. For the station tender's use, two signal systems are installed in cach hoisting compartment, and he is the only employee authorized to use them. One system is known as the "AC " or station bells, as it is operated from the 110-volt, 60-cycle, power service; the other system, called the "DC" or shaft bells, takes its energy from closed-circuit primary batteries. As a supplemcnt to the two main signals, a buzzer system is installed The general arrangement is similar to the main signal, except that there is a mine buzzer at each station. When a signal switch connected into the buzzer system is pulled down, all buzzers arc operated, thus notifying the station tender that he is wanted at seine particular level. Placed on the station posts, and within easy reach of the men on the cages are the signal pull switches for the main signals. The station, or "AC," pull switches are furnished with a short rope as shown in Fig. I, while the shaft, or "DC," pull switches are equipped with ropes that extend down the shaft past the next station. To avoid all confusion in the use of the three signal systems, a standard arrangement has been adopted in all mines for the location of the pull switches. Fig 2 illustrates the position of the pull switch at the various mine stations for the main signal systems, but it does not show the buzzer pull switch; this is fixed to the roof timbers about 25 ft. back from the shaft. If the skip pockets are a considerable distance below the station, a pull switch for each main shaft compartment is connected to the "AC" system and placed at this point. However, if the distance is short, a light cord is attached to the station pull switches and dropped down to the skip pocket.

Jan 1, 1923

By C. A. Mitke

During September, 1911, the fire area in the Lowell mine continually increased and gases resulting from the fire came through the upcast shaft. These gases contained such a large percentage of sulphur dioxide that the men were unable to go up and down on cages, and, within a comparatively short time, repairs in the shaft mere found to be necessary. Since the fire was in sulphide ores and extended into certain timbered sections, the gases contained varying amounts of SO2, CO2, and perhaps, at times, CO. The temperature in the shaft was generally about 97", and the relative humidity from 97 to 99.5 per cent. The corrosive action of the fumes became apparent when the cables had to be changed more often than usual, the heads of lag screws in the guides of the shaft disappeared, and the cages needed frequent repairs. It also became necessary to repair two compartments of the shaft by putting in 150 ft. of new guides between the 600 and 800 levels and lag screws in nearly all the old guides from the surface to the 800 level. 2. Ordinary Methods of Testing Helmets which were Unsatisfactory. These conditions required all work to be done by men wearing oxygen helmets. The Draeger type was tried, and was used until all repairs were completed. At first the helmets were tested for air circulation and air tightness and the injector mas tested by water gauge according to the methods recommended by the Draeger Oxygen Apparatus Co. Six arrangements, covering these different tests, are illustrated in the catalogue and circulars of the company. After the above tests had been made on the oxygen apparatus, the men still complained about leaky helmets. Small quantities of gas entered the helmets and could not be detected by these methods. The

Jan 1, 1914

By R. S. Dean

MANY studies have been made of the properties of steel produced by adding varying amounts of sponge iron to the charges used in steel-making furnaces.1-3 The results of these previous studies, however, have failed to disclose a reason for the belief of steelmakers that steel made in this way is definitely different from steel made entirely from scrap or iron melting stock. This paper deals chiefly with the structure of the sponge iron, of the wrought iron made by welding the sponge iron into blooms, and of the steel made by melting the forged and rolled blooms. It is believed that the structure of the final steel is inherited from the ore and that this inherited structure produces marked differences in the properties of the steel and explains the feeling of steelmakers which is based on their experience. Three kinds of sponge iron were used in this investigation: One made from a limonite ore reduced with natural gas, one made from a hematite ore reduced with natural gas, and one made from a magnetite ore reduced with charcoal. The sponge iron made by reduction with natural gas

Jan 1, 1935

By J. Philip Neal, Carroll P. Rogers

Feldspars, the most abundant minerals of the igneous rocks, occur in numerous forms and mixtures. The feldspars of commercial significance are found in widely distributed pegmatites as large crystals usually free of iron- bearing impurities and thus suitable for hand-cobbing, and also in larger bodies where the ore contains various types of feldspar inter- mingled with quartz and relatively free of iron- bearing impurities, or at least readily unlocked from impurities present at relatively coarse mesh. The latter type of ore includes some pegmatites, and the ''alaskite" bodies so common in the Spruce Pine district of North Carolina. On the west coast of the U.S. and in Oklahoma there is-r has been--commercial recovery of natural feldspathic sand as a source of alumina in glass and ceramics. "Aplite" in commercial terminology is a light-colored igneous rock with a granitic composition and a fine sugary texture, often banded with readily removable iron impurities. Two areas in Virginia produce aplite for the glass industry: one located in the vicinity of Piney River, Amherst County, and the other near Montpelier in Hanover County. According to Deer et al. (1966) the word feldspar derives from the Swedish feldt or falt (field) and "spath:" chunks of rock appearing in tilled ground overlying granite. Castle and Gillson (1960) indicate a Germanic origin, citing "spat," which is said to refer to any transparent or translucent material which is readily cleavable. The term "spar" has in the past been applied to minerals other than feld- spar, such as barite, calcite, and fluorite. It is correct to call the latter "fluorspar." There is a true barium feldspar, but it is rare and of no present economic importance. What is recognized as feldspar or "spar" by present producers and consumers consists of three silicate minerals which, if pure, would have the formu- las KAISi,O, (microcline or orthoclase), NaAlSi,O, (albite), and CaAl,Si,O, (anorthite). These are almost never found in pure form in nature, but occur together in great abundance in a three-component system. A considerable number of different combined ratios of these three exists, with the exception that isomorphism between potassium spar and calcium spar is very limited. User specifications for feldspar products are largely built around the prevalent naturally occurring ratios. Pas- sages following will refer to "K-spar," "Na- spar," or "Ca-spar." Nomenclature and Descriptive Terms Relating to both the mineralogy and the economics of feldspar are certain terms whose coverage it is useful to specify. Commercially, aplite is a feldspathic rock mined and beneficiated in two locations in Virginia, in which both titanium and feldspar minerals are present-the latter now being the major, if not the only, economic product. Technically, the term aplite when applied to this rock is of questionable accuracy. But, in light of accepted commercial usage, the term will be here used to designate it. Regarding the Virginia rock, Ross (1941) is cited.

Jan 1, 1975

By O. W. Ellis

IN VIEW of the extensive use of the brasses and bronzes in engineering practice it is indeed surprising that so little scientific work has been done on the oxides in these alloys. Recognition of the ill effects of these compounds is universally accorded, both in foundry procedure and in such specifications as cover the melting of these useful mixtures. In the latter, limits, for example, are placed on the proportions of scrap metal in the charge, and clauses governing the use of fluxes are included, the addition of fluxes to the charge being made with the object of avoiding oxidation during the process of melting and of subducing and separating non-metallic matter from the melt.1 In the manufacture of brass it occasionally, though rarely, occurs that the virgin metals, copper and zinc, alone are used. In the event of virgin metals being employed, that of the higher melting point is always melted first. If it is melted under suitable conditions, little or no oxidation will occur. Whether oxidation has occurred or not, however, can best be determined by microscopic examination of a sample taken from the melt.

Jan 1, 1930

By Heinrich Ries

With the rapid development of Canadian industries calling for the use of fire-brick for the lining of furnaces or cement-kilns, for constructing brick-kilns or coke-ovens, for lead-furnaces, etc., the question has often arisen whether the provirices within the Dominion have not the necessary raw materials for the manufacture of such refractory wares. As an indication for the need of such products in Canada, me find that the imports in 1910 amounted in value to $519,454. The materials came in part from Great Britain, and part from the United States. Those supplied by the latter country are obtained largely from Pennsylvania and Ohio, and when shipped to distant points, such as British Columbia, the item of transportation is a serious factor. Scotch fire-brick is used both in eastern and western Canada, but in the latter case the shipments are made by water route to Vancouver. During the past four years I have been investigating the clay-deposits of Canada, for the Canadian Geological Survey, and while all types of clay have been included in the study, special pains have been taken to ascertain the occurrence of refractory clays. As a result of this work we are able to report on the existence of beds of refractory clays at the followiug localities: Inverness and Shubenacadie, Nova Scotia; St. Remi, d'Amherst, Quebec; Dirt Hills and Cypress Hills, Saskatchewan; Sumas Mountain, near Clayburn, B. C., and Kyuquot, on northwestern Vancouver Island. A map of Canada, showing the fire-clay deposits, is given in Fig. 1. It is possible that other deposits may be discovered in the future in districts remotely located from the present lines of railroad.

Jan 1, 1914

By Herbert Clark Hoover, Lou Henry Hoover

MOST illustrious Princes, often have I considered the metallic arts as a whole, as Moderatus Columella2 considered the agricultural arts, just as if I had been considering the whole of the human body ; and when I had perceived the various parts of the subject, like so many members of the body, I became afraid that I might die before I should understand its full extent, much less before I could immortalise it in writing. This book itself indicates the length and breadth of the subject, and the number and importance of the sciences of which at least some little knowledge is necessary to miners. Indeed, the subject of mining is a very extensive one, and one very difficult to explain ; no part of it is fully dealt with by the Greek and Latin authors whose works survive ; and since the art is one of the most ancient, the most necessary and the most profitable to mankind, I considered that I ought not to neglect it. Without doubt, none of the arts is older than agriculture, but that of the metals is not , less ancient ; in fact they are at least equal and coeval, for no mortal man ever tilled a field without implements. In truth, in all the works of agricul- ture, as in the other arts, implements are used which are made from metals, or which could not be made without the use of metals ; for this reason the metals are of the greatest necessity to man. When an art is so poor that it lacks metals, it is not of much importance, for nothing is made without tools. Besides, of all ways whereby great wealth is acquired by good and honest means, none is more advantageous than mining ; for although from fields which are well tilled (not to mention other things) we derive rich yields, yet we obtain richer products from mines ; in fact, one mine is often much more beneficial to us than many fields. For this reason we learn from the history of nearly all ages that very many men have been made rich by the

Jan 1, 1950

By R. L. Doan

WHEN the Plutonium Project was started in the spring of 1942 there was no technology to produce uranium metal of the required purity. Not only was there no such metal available; no one knew how to make it or fabricate it after it was made. Since this time vast technical effort has been ex-pended in the atomic energy field. A short 15 years later the metallurgy of uranium is probably better known than that of any other metal, with the possible exception of steel. At the beginning of the 1942 drive to obtain pure uranium metal the most available raw material was black uranium oxide (U3O8) of about 92 pct purity from the Great Bear Lake region of Canada. It took only three months for the project chemists to develop a process for bringing the purity of this oxide up to 99+ pct and another three months for Mallinckrodt Chemical Co. of St. Louis to build the purification plant and get it into operation. In early summer of 1942 the purified brown oxide (UO2) started moving to the Metal Hydrides Co. in Beverly, Mass., and to the Westinghouse Research Laboratory in Bloomfield, N. J., both of which had been granted Government contracts to try to make pure uranium metal.

Jan 9, 1957

By W. H. Basssett

THE amount of oxygen present in refined copper bears an important relation to the effects of various impurities on physical properties of copper, as well as the effects of reducing gases at higher temperatures. It seems fitting at this time, when the effects of reducing gases on copper are being discussed, to describe methods that have proved satisfactory for the determination of oxygen and sulfur, and to present some results obtained by investigation of these methods in the authors' laboratory. The procedure for the determination of sulfur is closely interrelated with that for oxygen and has, therefore, been included. It was first proposed by Hamper that oxides in copper could be accurately determined by the loss in weight sustained by finely divided copper when reduced at red heat in pure hydrogen, or by the weight of water produced. Hampe's method was later modified by Archbutt,2 who established the accuracy of the method and demonstrated that equally accurate results were obtained by noting the loss in weight or by weighing the water formed. The determination of oxygen by heating in carbon monoxide has been proposed by West.3 In our hands this method has given slightly lower results than obtained by heating in hydrogen.

Jan 2, 1926

By R. F. Campbell, R. F. Miller

SIXTEEN steels containing different combinations of chromium and molybdenum, in amounts up to 5 per cent of each element, were examined for microstructure and hardness after air cooling and after furnace cooling from suitable austenitizing temper- [ ] atures. Diagrams summarizing the structures and hardness resulting from these two cooling rates are presented (Figs. 3, 4, 7).† Data were also obtained on the influence of these two elements, individually and in combination, on the depth 0f decarburization observed after furnace cooling (Fig. 8). COMPOSITION OF MATERIAL The chemical composition of the steels investigated is given in Table I. The plain carbon steel was made in a 25-ton Heroult electric-arc furnace, while the alloy steels were made in a 4.5-ton Ajax-Northrup elec- [ ] tric induction furnace. The cast ingots were hot-rolled to I.75-in. bars. AIR-COOLED SERIES The I.75-in. bars were forged to flat plates, 0.25 in. thick, from which specimens 0.5 in. wide by 2 in. long were cut. The specimens were pretreated to improve their homogeneity by heating to I830°F. (1000°C.) for 20 min. and oil quenching. They were then reheated to I740°F. (950°C.) for one hour and air-cooled, after

Jan 1, 1941

By J. M. Lovejoy

Various estimates have been made as 60 the percentage of oil left in a field after the wells have become so small that it is no longer practical to produce them. Engineers have given the matter much study and can substantiate their figures by data taken from fields from the Appalachians to California. The average oil sand has a porosity of about 20 per cent., which gives a capacity per acre-foot of approximately 1500 bbl. The sand thickness in Oklahoma pools averages 20 ft. With 20 per cent, porosity and a 20-ft. sand thickness, the capacity per acre is 30,000 bbl., yet these pools will seldom yield more than 5000 bbl. to the acre. These figures gupport the theory that at least 50 per cent. of the oil remains in a sand after all known methods to recover it have been used. Certainly we can never recover all the oil, unless in years to come oil becomes so rare and yet so necessary that the price will justify sinking shafts into the abandoned fields and regular mining methods of drifting and stoping. However, with improved methods of production and conservation of the natural agencies of expulsion, we should be able to increase recovery. It is with this in mind that this paper, relating to the effect of back pressure on wells, is presented. Except in the fields where production is caused by hydrostatic pressure, the chief agency for getting oil out of the sand into the hole is the gas that occurs with the oil. After the pressure has declined, probably gravity also is a factor, but not an important one. With a given amount of oil in a sand and a given amount of gas occurring with the oil, the ratio of gas volume per barrel of oil is the key to the ultimate recovery from that sand. Our efforts should be along lines that will lower this ratio and make the gas, the agency given us by nature, do its work better and yield more of the oil, of which it is a part. T. E. Swigart,' of the U. S. Bureau of Mines, has published an extract of the paper he is preparing under the title "The Effect of Back Pressures. on Wells." The experiments described were made on two

Jan 1, 1924

By N. Brown, M. Herman

ORDERING'S effect on the creep strength and other plastic properties of metals is unknown at the present time. Sachs and Weerts' attempted to compare the mechanical properties of the ordered and disordered state by comparing a quenched specimen with one annealed for a long time at a low temperature. This experiment is unsatisfactory because it introduces a possible effect from quenching. Barrett' used a hot impact test, but his method was not sufficiently sensitive to indicate any discontinuity in plastic behavior in the neighborhood of the critical temperature. On the theoretical side, Fisher9 as suggested that short range order would strengthen an alloy, but he gives no conclusions as to the effect of long range order. Cottrell" has discussed the interaction between long range order and dislocations, but does not indicate whether slip in a completely ordered alloy without domain boundaries is appreciably more difficult than slip in the disordered state. Because order exists in so many alloy systems, it is most important to prove experimentally whether long range order weakens or strengthens a metal. This investigation used -brass because: 1) it orders

Jan 1, 1957

By G. E. Agar, A. L. Mular

G. E. Agar (Manager, Minerals Processing Research, International Minerals & Chemical Corp., Skokie, III.) — The author notes a discrepancy between the parameters a and ß which are the slopes of the size distribution and energy-size modulus plots respectively. The reason for the discrepancy and the systematic decrease in the magnitude of a with grinding time is abundantly clear from the work of Fuerstenau8 on dry grinding. Fuerstenau shows very clearly in his Fig. 5 that at short retention times the parameter a is the same as that obtained by sizing over the complete size range. From this figure, it is obvious that sizing to only 400 mesh gave distribution curves similar to Mular's - that is, the slope apparently decreased systematically with increased grinding. As a consequence of the improper determination of a, the magnitude of ß given by Mular must be larger than the true value. In order to demonstrate this, the following Fig. 6 was taken from Mular's paper (his Fig. 1). Fuer-stenau's results show that we can approximate the correct value of K by drawing lines parallel to the short retention time curves through the 400-mesh

Jan 1, 1963

By A. H. Daane, J. F. Haefling

The limits of miscibility in some of the uranium rare-earth alloy systems have been determined in the temperature range 1000°to 1250°C. The solubilities of lanthanum and cerium in uranium are greater than those of the remaining rare earths by a factor of more than two. The solubility of uranium is greater in cerium, braseodymium, and neodymium than in the other rare-earth metals studied. The values found in this study are in qualitative agreement with those which might be expected if the solubility rules of Hildebrand and Scott are applicable. AS interest in nuclear reactors intensifies, many new types of fuels are being suggested in attempts to improve the economics of some of the proposed reactor schemes. To remove some of the difficulties inherent in the use of solid-fuel elements and their reprocessing, many types of liquid-metal reactors have been suggested. One of the more attractive features of several of these reactor concepts is that they include a continuous or semicontinuous process for the extraction of fission products and "bred" fissionable materials from the fuel, utilizing immiscible metal extractants. This would enable a much higher burn-up of fissionable material to be achieved and would present a very attractive economic picture. Several studies have been reported on equilibrium systems in which there exists a high degree of immiscibility between uranium and another metal that might be used as an extractant in such a processing scheme.' Two of these systems in which a high degree of immiscibility exists are those of uranium with the two rare-earth metals, lanthanum, and cerium. Since the rare earths constitute a significant fraction of the fission products, their removal is of prime importance. It is reasonable to believe that this might be accomplished by equilibrating a rare-earth phase with the contaminated uranium fuel in the liquid state. In order to make a more complete study of those systems which would be of interest either as extractants in a liquid-liquid extraction process, or as fission products formed in the fuel, the alloy systems of uranium with lanthanum, cerium, praseodymium, neodymium, and samarium were studied in some detail in the temperature range 1000" to 1250°C; less detailed studies were made with the other rare earths. In addition to being of value to the reactor program, the data obtained in this study should be of help in making a study of the role played by the electronic structures of metals in determining the nature of metallic solutions. The unique electronic structures of the rare-earth elements make them particularly interesting in this respect. EXPERIMENTAL The usual procedure for a solubility determination was to seal equal volumes of uranium and the particular rare earth in a tantalum crucible under an atmosphere of helium; this crucible was then sealed in a stainless steel jacket in an atmosphere of helium. These samples were equilibrated by repeated inverting of the crucibles in a furnace for 15 min at the desired temperature, left in an upright position for 15 min to permit separation of the two phases, and then quenched under a stream of water. In some runs the temperature of the furnace was held 50' to 100°C above the desired quenching temperature while inverting in order to insure good mixing. However, it was found that above 1200°C the crucibles were subject to failure and for these runs the furnace temperature was not raised above the desired quenching temperature. A small amount of tantalum was dissolved in the uranium and the rare earths in these runs, a maximum of 3 wt pct in the uranium phase at 1250°C and up to 1 wt pct in the rare-earth phase at this temperature. On cooling, the major portion of this tantalum precipitated as primary tantalum crystals. Any residual tantalum would probably have a negligible effect on the mutual solubility of uranium and the rare earths in each other. Samples for analysis were cut from each phase with an abrasive cutting wheel; the region near the interface between the two metals was carefully avoided. In the case of the rare earths with melting points above 1250°C no solubility data were taken on the rare-earth phase since this phase could not have achieved equilibrium in a reasonable length of time. (For the same reason no data were taken on the uranium phase below its melting point of 1132°C.) Equilibrium appeared to have been reached in the uranium phase in these cases although the rare-earth phase had not melted. To verify this, samples were melted together in an arc furnace similar to that described by Kroll.2 These samples were sub-

Jan 1, 1960

By M. E. V. Plummer, F. E. Beamish, J. C. Hole, J. M. Kavanagh

Prior researches have shown that the iron-copper-nickel content of platinum concentrates may be reduced by carbon to form a collecting alloy for the platinum metals in a manner exactly analogous to the formation of the lead fire assay button. The nature of the iron-copper-nickel alloys with the platinum metals has been investigated. Palladium and probably some of the other platinum metals form solid solutions with this alloy. ONE of the greatest known reserves of the platinum metals is to be found in the nickel, copper, iron sulphide deposits of Northern Ontario. The very large tonnage of copper-nickel ore processed makes the Sudbury district a significant world source of the platinum metals, the latter being recovered as byproducts in the electrolytic refining process for copper and nickel. Chalcopyrite, pentlandite, and pyrrhotite are carriers of the platinum metals;' these minerals contain from 0.03 to 2.0 ppm of the noble metals. The analysis of the above ores for the platinum metals necessitates an initial concentration of the minute quantities present in the ore. The method usually employed involves the extraction of the noble metals by molten lead with or without small proportions of silver. The lead is then separated from the precious metals by cupellation, a process which involves absorption by the cupel and volatilization of lead oxide, leaving the precious metals collected in a silver bead on the surface of the cupel. The collection by lead is probably achieved by a process of dissolution followed by some degree of segregation in the lead alloy since the cold button is seldom uniform in composition. With silver-lead alloys this process of liquation has been used to re- cover pure lead since, during the cooling period, crystals of pure lead separate and silver becomes concentrated toward the center of the solid.' Platinum and gold liquate in a manner similar to silver which may account for the successful recovery of platinum by fire assay even though it is considered insoluble in a solid lead medium. 3 In the case of iridium the liquation process may be a disadvantage in that the iridium may appear in the outer areas of the button and thus be lost mechanically during the handling processes. In any case the deficient alloying characteristics of lead for the platinum metals encouraged attempts to find an improved collecting alloy, and by analogy with aqueous extractions, preferably one in which solid solutions would be readily formed. Since, beyond a certain minimum solute to solvent ratio, the formation of a solid solution is accompanied by a lattice distortion, one would expect some relationship between the atomic diameters of any two metals and their tendency to form a solid solution. In one survey5 the hypothesis was put forward that when the atomic diameter of the solute differs by more than about 15 pct from the solvent, the "size factor" is unfavorable and the formation of a solid solution is restricted. On the other hand, when the atomic diameters are within this limit the size factor is favorable and solid solutions are readily formed, e.g. the transition metals of Group VIII having similar radii form solid solutions over wide ranges of composition.6 Even with a favorable size factor, elements having different crystal structures cannot form a continuous series of solid solutions. Cell dimensions alter as the concentration of the solute increases, causing a

Jan 1, 1962

By Walter S. Lutz, J. T. Griffith

The rainfall during the last six months of 1942 in Scranton and vicinity was 24.06 in.—only 4.35 in more than the average for this district in any equivalent period—yet that rain forced The Hudson Coal Co. to handle 38.8 tons of water for every ton of coal mined. It filled to overflowing, or to a higher level, 14 flooded mine areas holding, in total volume, 8.3 billion gallons of water in storage; brought about a pumpage of 11.4 billion gallons in the months of December 1942 and January, February and March 1943 Half of the total energy generated or purchased (44,322,980 kw-hr.) was required to keep the mines sufficiently free of water to permit the mining of coal during a period of much needed output. Fig. I shows the extent to which this flooding of exhausted and idle properties has proceeded, and is known to be proceeding further, at the upper end of the Northern field. This rainfall (24.06 in.) means 80,559,444 tons of water on approximately 46.2 sq. miles of area tributary to the pumping plants. During the high rainfall period, 72,687,661 tons went underground, being pumped at the stations in this territory. This means an inflow of 88per cent, a runoff of 12 per cent compared with 64 per cent during normal conditions in a normal region. During this period no floods, either surface or underground, had to be dealt with, although the streams and rivers were high on several occasions. In general, the rainfall for the first three months of 1943 can be described as heavy but not abnormal.9 These figures not only indicate the large volumes of water to be handled but, by their very size, they also emphasize that the mine-water problem is not to be conquered, at least from an economical standpoint, by merely buying and installing more and more pumps. Into the solving of this water problem must go much planning, adhering to the principle of keeping the highest percentage of water at the highest possible level for the longest period of time; the storage of huge volumes in sumps capable of being reduced after the flood inflow and at rates less than the inflow; plans for prevention of surface inflow; provision of the minimum of pumping capacity arranged to as nearly 100 per cent pumping load factor as is possible; intercompany joint pumping plants; the conducting of water from one plant to another and from one property to another over distances measured in miles; priorities in power to the threatening situations; and. balance of the necessities and dangers existent in one colliery over another, day by day, when quantities of water are running high. Despite these astronomical figures of water volumes, their disposal to the surface is accomplished reasonably cheaply because, although the annual cost of $575,020 is a large sum, the cost per ton is about 0.1168 cents. Credit for this goes

Jan 1, 1947