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By W. B. Gogarty

With flow of non-Newtonian fluids in porous media, effective viscosities are needed for use in the Darcy equation. These viscosities depend on the rock parameters and flowing conditions. In this investigation, rheological and flow results were correlated to develop an expression for calculating effective viscosities. Surfactant-stabilized dispersions of water in hydrocarbon were used with consolidated sandstone cores of different permeabilities. The average shear rate in a core was related to the permeability and porosity of the core and the frontal velocity through the core. By using the correlation obtained for determining effective viscosity, experimental and theoretical values were compared for each fluid system by determining average and maximum errors. For the fluid system showing the largest average error, the correlation fit 38 experimental points with an average and maximum percentage error of 4.3 and 14.8, respectively. For the fluid system showing the least error, average and maximum percentage errors of 1.8 and 4.3, respectively, were calculated using 29 experimental points. INTRODUCTION Use of non-Newtonian fluids in the petroleum industry is not new. Fluids of this type have been used for many years as fracturing agents and drilling muds. Recently, attention has focused on the use of high molecular weight polymer solutions for secondary recovery. Results have been reported on studies relating to the flow behavior of polymer solutions in porous media.1-4 Each study gives the viscosity in the Darcy equation as a function of the rheological properties of the fluid, the characteristics of the porous medium and the pressure gradient. The functional forms of the reported expressions differ somewhat in each study. The first three studies used unconsolidated porous media while the fourth used a single consolidated core. Because of the limited information available on the flow of non-Newtonian fluids in porous media, further investigation was undertaken in this area. We selected non-Newtonian fluids that did not contain high molecular weight polymers in order to minimize core plugging. The over-all objective was to gain a better understanding of the flow behavior of non-Newtonian fluids in consolidated porous media. Specifically, our goal was to determine the relationship between the average shear rate in a core and the frontal velocity. Because of this goal, it was necessary to determine the effect of permeability on the shear rate-frontal velocity relationship. We wanted to replace the viscosity in the Darcy equation with an expression relating to the average shear rate in the core and the rheological properties of the non-Newtonian fluid. THEORY For a time-independent, non-Newtonian fluid, the apparent viscosity is a function of the shear rate. This relationship is given by µ = F(v')...........(1) With Eq. 1, a single value of shear rate determines the apparent viscosity at that shear rate. With flow in porous media, a spectrum of shear rates occurs at any average throughput. An average shear rate v' can be used to represent the spectrum of shear rates that exists within the core. By using v' and the rheological data given by Eq. 1, an effective viscosity is determined for the flowing fluid. If v' is the correct average, µe becomes the appropriate viscosity for use in the Darcy equation. Under these conditions, flow rate-pressure drop relationships can be determined for non-Newtonian fluids. HOW the correct average shear rate might be related to the frontal velocity through the core and the characteristics of the porous media will now be considered. Later, the experimental data are presented that indicate the validity of these

C. N. FEnner, New York City (communication to the Secretary) : A possible explanation of some of the' phenomena of amalgamation cited by Mr. Bayliss and others has occurred to me. We know that if, to a quantity of mercury, gold and silver are added until a putty-like paste is formed, and if this mass is spread on a flat surface and pressure is applied, a more fluid portion of the mercury will be squeezed out from the rest, carrying gold and silver with it. The proportion of gold to silver will depend, I think, upon various causes and conditions—the relative chemical affinity which gold and silver have for mercury; the amount of pressure used; the presence of other metals:

Jan 1, 1898

By D. K. Deardorff, Earl T. Hayes

An improved technique is described for the accurate determination of melting points of metals in the temperature range 1500' to 2500°C. The improvements consist of gradient heating and refinements in cavity preparation to obtain true black-body conditions. The melting point of hafnium, as determined by this method, is set at 2222°±30°C. This is over 200°C higher than one of the values reported earlier. Discrepancies in the previously reported values for the melting point of hafnium are explained. The melting points of zirconium and titanium are found to be 1855O±15OC and 1668°±10°C, respectively. Reproducibility of results was ±3OC. PRIMARILY, this report is being made to correct a 1975o±25oC1 value for the melting point of hafnium, and to present an improved method for melting point determination. As a matter of interest, the technique was also applied to determining the melting point of zirconium and titanium. There is a wide difference in the melting point of hafnium as reported by competent investigators. DeBoer and Fast' reported a value of 2230°±500C, and later work of McPherson, as reported by Aden-stedt, placed the melting point at 1975o±25oC. Zwikker" calculated that the melting point was 2430°C. In resolving this discrepancy, improvements were made in the procedure for determining the melting points of refractory metals in the range 1500" to 2500°C. Special techniques are necessary to determine the melting point of these metals accurately. Since the metals oxidize in air above 900oC, the determinations must be carried out in an inert gas or vacuum. Also, every known refractory contaminates them to some extent. In addition, the attainment of true black-body conditions is always difficult. DeBoer and Fast actually determined the melting point of Hf-Zr as-deposited iodide process alloys and extrapolated to 100 pet Hf. McPherson employed a tungsten wire suspension similar to that described by Schramm, Gordon, and Kaufmann,1 and used hafnium metal produced by the iodide process. There was no apparent reason for the wide spread in melting points, since the quality of the metal was very good and the work was under the direction of highly competent investigators. Retracing some of this work revealed one understandable error in the case of hafnium, and led to development of an improved technique for determining melting points of reactive metals in the range 1500" to 2500°C. Material Crystal bar hafnium, zirconium, and titanium were used for this work, with analyses as shown in Table I. The hafnium was of the highest purity that has been prepared, though not as pure as the zirconium and titanium. At the instigation of the Pittsburgh Area Office of the AEC, a special lot of Hfo2 was purified, converted to the tetraflouride, and bomb-reduced with calcium, all at the Iowa State College Laboratories. This crude hafnium metal was then refined by the iodide process at the Foote Mineral Co. All specimens were cut with a Sic wheel, ground, pickled, and dried carefully before use. Procedure General Tungsten Suspension Method—In this method, a small specimen is suspended by a fine tungsten wire in a slender, induction-heated tungsten or tantalum cylinder, all under vacuum. The melting point is determined by heating the specimen slowly while observing it with an optical pyrometer focused upon a portion of the specimen that radiates as a black body. This means that there should be no reflected radiation, either from colder objects near the pyrometer or from hotter surfaces. The induction heater would be the only hotter object and, if it is slender enough, the specimen will attain the same temperature. Often a slender hole is drilled into the specimen as a source of black-body radiation. This was the general method used by McPherson in obtaining his value of 1975°C for the melting point of hafnium. In trying to repeat this work, it was found that the points of contact between the

Jan 1, 1957

By J. M. Clark

(Wilkes-Barre Meeting, June, 1911.) For some years past, those interested in the development of the increasingly important mining industry of Canada, have urged the adoption by the Dominion Parliament of a federal mining-law, which would have the force and stability of statutory enactment. At present, placer-mining in the Yukon Territory, is governed by the Yukon Placer Mining Act. All other mining under federal jurisdiction is governed by 'Orders in Council and Ministerial Regulations. In the earlier stages of development, it is perhaps a matter of necessity that these important matters should be so dealt with; but it is now felt that the time has come when mining-rights in the extensive regions under federal control should be put on a permanent basis, -and that any changes required from time to time should be made only after full and open discussion in Parliament. A short sketch will suffice to indicate how vast and varied the interests affected really are. When the Dominion of Canada was constituted by the Imperial Statute known as the British North America Act of 1867 (which came into force by proclamation on July 1 of that year), it comprised only the present Provinces of Ontario, Quebec, Nova Scotia, and New Brunswick; but provision was made for the inclusion of Newfoundland, Prince Edward Island, British Columbia, Rupert's Land, and the North West Territories. Subsequently Rupert's Land and the North West Territories were acquired, the 'Crown Colonies of British Columbia and * SECRETARY'S NOTE.-Mr. Clark, an eminent Canadian lawyer, and joint author of the treatise on "The Law of Mines in Canada," has been requested by the Do¬minion Government to prepare a Federal mining-law, and presents this paper, by invitation of the Council, in order to obtain, if possible, useful suggestions from members of the Institute.-R. W. R.

Apr 1, 1911

By J. E. Nelson, R. J. Bonnis

Recent completion of Cyprus Bagdad's $240-million modernization and expansion program has registered a 700% increase in ore production with only a 50% increase in labor. Elements of this remarkable achievement include the application of large-scale mining equipment as well as the selection of the latest in processing hardware. Most important, however, was the early recognition that Bagdad's labor personnel is its most important asset.

Jan 4, 1978

By B. W. Levinger

THE system Ti-CI- has been studied by several investigators." ' Though titanium and chromium are completely miscible at high temperatures, an intermediate phase of the approximate atomic proportions TiCr, has been identified at various compositions between 60 and 68 wt pct Cr. The structure of this phase was established as the cubic C15 (MgCu2) type with 24 atoms per unit cell and a lattice parameter 6.929 kX.2 During a study of the ternary system, Ti-Mo-Cr,5 the existence of a high temperature modification of the TiCr, phase was discovered. In a series of alloys annealed at 1300°C and containing from 60 to 70 wt pct Cr and 5 pct Mo, a new phase was present which did not correspond to either ß solid solution or TiCr,. By trial, the new phase was identified to be of the hexagonal C14 (MgZn2) structure with 12 atoms per unit cell. Further work showed that the hexagonal structure was. in fact, also present in binary Ti-Cr alloys quenched from high temperatures. To make the identification more certain, the intensities of the various reflections were calculated assuming a composition TiCr2 and C14 structure. Table I lists reflection planes, interplanar distances, calculated intensities, and a comparison of these values with the lines of a binary Ti-Cr alloy (66 pct Cr) annealed for 20 min at 1385°C and water quenched. Since high angle lines were more diffuse, the correspondence between visually observed and calculated intensities was not as good at these angles. Lattice parameters were computed to be a = 4.922 kX, c = 7.945, c/a :- 1.614. The corresponding interatomic distances are: titanium to titanium distance, 3.00:, kx, chromium to chromium distance, 2.43, kX, titanium to chromium distance, 2.88,, kX. These compare to 3.00, 2.45, and 2.87 kX in the cubic phase, respectively.' The atomic positions in the C14 structure are as follows: Titanium 1/3, 2/3, Z; 1/3, 2/3, 1/2: 2/3, 1/3, i; 2/3, 1/3, (1/2-z); Chromium 0, 0, 0: 0, 0, 1/2; 2x, 2, 1/4; 232, x, %; X, 22, 1/4; X, 2x, 3/4; x. x, 1/4; x, x, 3/4; The values of x and z were calculated for the alloy mentioned and found as follows: z — 0.061, x = 0.165. The values assumed in the intensity calculations were those for an ideal close-packed lattice or z = 1/16, x = 1/6. Work in the Ti-Mo-Cr system indicates that y2 the hexagonal modification of TiCr2, is the stable phase above 1300°C, while y1 with the cubic structure is stable below 1000°C. X-ray examination of a number of alloys annealed at intermediate temperatures showed that the hexagonal and cubic phases can coexist. Alloys quenched from 1000°C and annealed at 1100" and 1200°C showed small amounts of y2 at the higher temperature. A considerable amount of y, seemed present, however, in cast alloys annealed at 1100°C. It further appears that there is a small but definite solubility range for both phases in the ternary system. Acknowledgment The results of this paper represent work carried out in conjunction with a project sponsored by Watertown Arsenal, Contract No. DA-11-022-ORD-272. References 'M. K. McQuillan: Journal Inst. Metals (1951) 79, p. 379. 2 P. Duwez and J. L. Taylor: Trans. ASM (1952) 44, p. 495. W. J. Van Thyne,. H.. D. Kessler, and M. Hansen: Trans. ASM (1952) 44, p. 974. 1 F. B. Cuff, N. J. Grant, and C. F. Floe: Trans. AIME (1952) 194, p. 848; Journal of Metals (August 1952). Unpublished Research, Armour Research Foundation. "H. J. Wallbaum: Ztsch. Krist. 103, p. 391.

Jan 1, 1954

A. V. ADAMSON,* New York, N. Y. (written discussion).-The experience of users of pulverized fuel in metallurgical work, particularly for open-hearth furnaces, has demonstrated that high ash and sulfur in pulverized fuel are a detriment, the sulfur in the coal entering into the finished product; hence, in this class of work it is extremely important, when pulverized coal is to be used, that the coal be selected with care, and only those having low percentages of sulfur be used, in combination with proper means for combustion. I have found that no general statement can be made as to the cost of pulverized coal, each installation being an individual engineering problem and necessitating a varying capital expenditure; as each installation has its own power cost, the actual cost of pulverizing varies between wide margins. It has been found that no general rule can he laid down as to either fineness or dryness; for some uses a wide range is permissible in both factors, while some classes of fuel require different treatment from others. Anthracite, coke breeze, and lignite ash will, under certain conditions, form slag, the melting point of the ash from fuel of this character being practically the same as of that from bituminous coal; furnace temperatures above the melting point of ash must therefore cause the formation of slag. However, it should he noted that furnace temperatures attainable with this class of fuel are not usually so high as those from bituminous coal, which probably explains the statement that the former do not slag. In a well designed furnace, temperatures above 2250° F. (1235° C.) will be obtained with that class of fuel, and slags will be formed. Too much attention apparently has been centered on high CO2 contents of stack gases. A high percentage of C02 is frequently obtained at the expense of the brickwork, the furnace temperature being increased by diminishing the excess air; a high percentage of C02 thus simply means a small proportion of 02.

Jan 12, 1918

By R. L., Fullman

During the past year there have been a number of significant investigations that have furnished evidence on the driving forces governing grain growth and on the role played by boundary impurities. Thus Burke has shown that in high purity alpha brass the rate of grain growth in the earliest stages is approximately inversely proportional to the existing grain size. This relation agrees with one derived by Zener assuming that surface energy was the driving force in grain growth. Also in confirmation of the surface energy hypothesis, Burke found that growth virtually stopped when the grain boundaries or even only the grain corners were melted.

Jan 1, 1949

By C. S. Barrett

W. Hofmann, J. Ziegler, and H. Hanemann—Having dealt with the same alloys in the winter 1941 to 1942, we want to give a short report on the generating of the hexagonal kappa phase by deforming the supersaturated alpha phase, which we then observed. This work was delivered as a Doctor of Engineering dissertation to the Technical University of Berlin by J. Ziegler in 1942. It still exists in two copies, somewhat damaged, a brief publication of it having been issued in Fiat-Review. Our work was started from the alloy Tombasil with 4.5 to 5 pct Si, 14.5 to 14 pct Zn, the rest Cu. Torpedo propellers were die cast from this alloy in Germany during the war. In order to improve this alloy, annealing was tried. By this treatment the alloy became at the same time harder and more brittle. A further research of this process was made in the Got-tingen University30 and the "Institut fÜr Metallkunde" of the Technical University of Berlin. It soon was apparent that the Cu-Si diagram at our disposal15,31,32 would not fit the observations. For this reason the pith of the matter became from then on the Cu-Si system. At that time we did not know of Smith's* and Andersen'sm latest diagrams. We first knew of them from Dr. Barrett's publication. Twenty-two alloys containing 2 to 11 pct Si were melted in a nitrogen atmosphere and generally homogenized for 2 to 4 hr at 800 °C. Part of the samples were then annealed at 700°, 600° and 500°. Annealing was followed by quenching in water. The phases corresponding to the various temperatures were identified by X-ray and microscopy. The Debye-Scherrer photographs generally were made of filings. The latter were produced after the last anneal of the samples, then equally annealed another 30 min in evacuated glass tubes and quenched in water. In the region of concentrations examined, the Cu-Si phases already known to us were observed: alpha, kappa (then called beta by us), gamma. By hot exposing an alloy of 7.69 pct Si at 800" and 750°,

Jan 1, 1951

By C. E. Arnold

THE CHAIRMAN (PERCY G. BECKETT, Globe, Ariz.).-When you are at Miami tomorrow, you will see a very interesting comparison on the surface of the two mining methods that are being employed there largely. In the case of the surface over the Inspiration mining method, you won't see very much left of the surface. Everything has gone down. In the case right at the line of the Inspiration ground and the Miami, you will see that the surface over the top slicing which the Miami company has been doing in that country has been riding down evenly and uniformly; and it gives a very marked comparison of the two types of mining, and, to a certain extent, of the different degrees of waste dilution. I would ilke to hear from Mr. Maclennan on this subject. F. W. MACLENNAN, Miami, Ariz.-A paper based on percentage extraction by shrinkage stoping is a difficult one to discuss for the reason that it is hard to arrive at extraction figures until a section has been completely mined out. In the Miami mine we are using a method of shrinkage stoping with narrow stopes and pillars. This ore has been completely broken up and we have started in at the far end to draw off the ore mass maintaining the top of the broken ore dipping at an angle of 60° away from the direction in which we are retreating. A very important point I think about drawing a large. mass of ore down at an angle rather than trying to maintain the top of the ore more or less horizontal is that drawing at a steep angle has a tendency to create a horizontal movement in the ore mass as well as the vertical movement of the ore traveling down to the drawing off chutes. We know that this takes place, on account of the horizontal movement of marked

Jan 12, 1916

By F. L. Fayers, J. W. Sheldon

It has been a matter of concern to the petroleum industry to determine what effect the capillary term has on saturation profiles, since these profiles determine ultimate economic oil recovery. In their original solution of the non-capillary two-phase flow problem, Buckley and Leverett&apos; showed that solutions of the two-phase flow equations became multiple-valued in saturation. Since it is physically unrealistic for saturation to have more than one value at a given position, Buckley and Leverett resolved this difficulty by introducing a saturation discontinuity or "shock". They evaluated the strength and position of the shock from material balance considerations. Recently Sheldon, Zondek and Cardwell&apos; have demonstrated that the method of characteristics can be used to solve this and related problems. Owing to capillarity it is physically unlikely that saturation shocks occur in an oil reservoir. Buckley and Leverett suggested that the effects of interfacial tensions should be included in the fluid flow equations, if the solutions are to give continuous single-valued saturation distributions. An analogy to this problem is encountered in the theory of wpersonic compressible flow where the introduction of the viscous term eliminates shock behavior. However, the mathematical form of the capillary term in the porous medium fluid flow equations differs from the viscosity term in the Navier-Stokes equation. This paper demons~rates that capillarity does eliminate the triple-valued behavior and indicates the magnitude of capillary and gravity effects on the saturation profile for a variety of systems. DERIVATION OF LAGRANGIAN AND EULERIAN FORMS OF THE DISPLACEMENT EQUATION The equations representing capillary, two-phase flow are given by applying Darcy&apos;s law and a material balance condition for each phase. The familiar Darcy and material balance equations are as follows. ^U*^0......<3, ^^r=°......c« S is the saturation of the water phase, and B the inclination of the porous medium. Pressures in the oil and water phases differ by the capillary pressure associated with the interfacial tensions, P.-P.=pAS)..........(5) where p, is determined experimentally. The porous medium is said to be oil-wet if P, > Po and water-wet if P, < Po. If the fluids are incompressible and the total volumetric flow rate, q, is constant, then v, f v,, = q...........(6) By eliminating P.. /»,, and v, from Eqs. 1, 2, 5 and 6 it follows that It is convenient to normalize the variables in the problem after the manner of Handy and Hadley% so that Eqs. 3 and 7 become where j,, = —, the fractional flow of water; (F, is a capillary pressure normalizing constant.) Substitution of Eq. 9 into Eq. 8 gives In this partial differential equation for an initial value

By Orson Cutler Shepard

The term "electrocapillary amalgamation" is used in this paper to designate amalgamation processes that depend upon electrocapillary phenomenon; i.e., the action of an electric current upon the surface tension of mercury at the contact with aqueous solutions. Electro-capillary amalgamation is selected as a name for these processes because the electrocapillary phenomenon has been found to be the effective agent in the use of sodium amalgam, as well as in the various processes using an electric current from a source outside of the amalgam. Amalgamation processes that depend upon supplying an electric current to the amalgam from an outside source, such as batteries and generators, have previously been called electrical amalgamation processes. There has been a tremendous amount of experimental work done on amalgamation processes involving the use of an electric current, as shown by the large number of patents issued on these processes: the earliest in 1885 and the latest in 1934l. Regardless of all the experimental work, the fundamental principles causing the operation of electrocapillary amalgamation processes have not been described. The explanation usually given is that an electric current keeps the amalgam bright and clean. Patent No. 328532 states: It is well known that when amalgam plates are used for collecting gold and silver from their ores the surfaces of these plates are liable to become tarnished or sickened by certain substances contained in the ores or in the current of water which is employed to carry the ore over the plates, and that in this condition they are unfitted for amalgamating the particles of gold and silver. To prevent this and to keep the surfaces of the amalgamation plates always bright and in a better condition for catching and amalgamating the particles of gold and silver I employ electricity in the following manner: . . . A similar explanation is given 49 years later, in patent No. 1953364: The sodium (Na) ions lose their charge at the cathode becoming sodium atoms, which do not react with the electrolyte, but follow the grounded electrical current through the mercury body producing in their passage sodium amalgam and liberate themselves in the amalgamation compartment when brought in contact with the fed

Jan 1, 1939

By Orson Cutler Shepard

The term "electrocapillary amalgamation" is used in this paper to designate amalgamation processes that depend upon electrocapillary phenomenon; i.e., the action of an electric current upon the surface tension of mercury at the contact with aqueous solutions. Electro-capillary amalgamation is selected as a name for these processes because the electrocapillary phenomenon has been found to be the effective agent in the use of sodium amalgam, as well as in the various processes using an electric current from a source outside of the amalgam. Amalgamation processes that depend upon supplying an electric current to the amalgam from an outside source, such as batteries and generators, have previously been called electrical amalgamation processes. There has been a tremendous amount of experimental work done on amalgamation processes involving the use of an electric current, as shown by the large number of patents issued on these processes: the earliest in 1885 and the latest in 1934l. Regardless of all the experimental work, the fundamental principles causing the operation of electrocapillary amalgamation processes have not been described. The explanation usually given is that an electric current keeps the amalgam bright and clean. Patent No. 328532 states: It is well known that when amalgam plates are used for collecting gold and silver from their ores the surfaces of these plates are liable to become tarnished or sickened by certain substances contained in the ores or in the current of water which is employed to carry the ore over the plates, and that in this condition they are unfitted for amalgamating the particles of gold and silver. To prevent this and to keep the surfaces of the amalgamation plates always bright and in a better condition for catching and amalgamating the particles of gold and silver I employ electricity in the following manner: . . . A similar explanation is given 49 years later, in patent No. 1953364: The sodium (Na) ions lose their charge at the cathode becoming sodium atoms, which do not react with the electrolyte, but follow the grounded electrical current through the mercury body producing in their passage sodium amalgam and liberate themselves in the amalgamation compartment when brought in contact with the fed

Jan 1, 1939

By PALMER H. TYLER

WHEN the Mid-Continent Section of the A. I. M. E. met at the roof garden dining room of the Tulsa Club on Monday evening, May 13, most of the members present came prepared with a credulity-stretching yarn of some sort or other, gathered from actual experience. Perhaps it was not realized at the time that such anecdotes would eventually burst into print, but while the excellent dinner was appeasing the inner man the word was passed around that informality and spontaneity of expression would characterize the meeting, with the result that the shackles of convention were eventually cast aside and the meeting waxed better and better until the hour grew ,late, and the chairman, L. G. E. Bignell, originator of the idea, brought to a close what was agreed to be a profitable and entertaining evening. The ball was started rolling by Paul Ruedemann of the program committee, who offered the following:

Jan 1, 1929

By W. L. Zeigler

DURING the middle 1880s, shortly after the discovery of silver-lead ores in the Coeur d&apos;Alene district of northern Idaho, it became apparent that concentration of the ores would be necessary to obtain a profitable product. Too much siliceous material was present for direct smelting, and the majority of the ores found at depth were too low in metallic content for economic smelting processes at the time. As the ores occurred in quartzite shear zones with siderite and quartz gangue, a large quantity of waste material was present in all the mines. As the galena was not finely disseminated, this made possible relatively good extraction of the argentiferous galena by coarse concentration. The first concentrators consisted mainly of coarse crushing, screening and jigging, principally by Harz jigs, the slimes being treated on buddies. Later Wilfley tables took the place of sand jigs and vanners superseded the buddies. Because of the marketing conditions, no attempt was made until 1900 to effect a recovery on the zinc minerals present, which were found associated in varying amounts with the galena. All through this period, the greater part of the production was obtained from mines containing ore assaying high in lead and low in zinc. Parts of some ore bodies would be reversed in this respect, so that ores high in zinc were left intact. During the decade after 1910, several important mines, The Success and The Interstate Callahan, containing ores high in zinc, were put into operation and were a material aid in the needed zinc production during World War I. Gravity concentration by jigs and tables was used during this period, with bulk flotation increasing in popularity for the treatment of the fine material that had already been treated by ordinary slime concentrating machinery. No extra fine grinding for flotation concentration was thought profitable at the time. TAILINGS DISCHARGED INTO STREAMS From the start of mining and milling operations in this district until 1904, no attempt was made by the various mills in the upper district to impound or stack their tailings. They discharged them directly into the adjacent creeks or streams, to be carried away by high water. The Bunker Hill and Sullivan and the Last Chance mines, both in the relatively flat valley of the district, stacked huge piles of the coarse jig tailings on the near-by river bottom. Rain and snowfall are heavy in the Coeur d&apos;Alene district, as it is on the heavily timbered Pacific slope of the Bitter Root Mountains. A heavy runoff occurs every spring and there is an occasional flood of disastrous proportions when warm "Chinook" winds accompanied by rain

Jan 1, 1947

By H. W. Gillett

CLYDE WILLIAMS has reminded me that in the fall of 1929, gave, in MINING AND METALLURGY, an account of the hopes and aspirations of Battelle Memorial Institute, which was then just swinging into initial operation; and that therein I remarked that B.M.I. should stand, as well, for Better Metallurgical Industries, since helping to better them was the Institute&apos;s aim. So he has suggested that some of the betterments of the past fifteen years might well be listed. A yearly summary of progress comes pretty close to the ultimate in futility, for everything proved of value in that year had its inception in earlier years, and everything really new has still to be proved. Plenty of things hailed as wonderful achievements for that year, by some enthusiasts invited to contribute to the summary, turn out in later years to be inglorious flops. But over a decade and a half, betterments that are really such become self-evident, and recounting some of them can be done without guesswork or wishful thinking. An inventory of what was known and utilized in 1929 compared to what is now known and used is not too hard to make. Perhaps the most clear-cut picture of what is known and used at a certain date is drawn by the handbooks, textbooks, and equipment catalogs of that date, with scientific periodical literature forecasting what knowledge may later be used when it is verified and assimilated. The tools available for production or for research limit the application of old and the finding of new knowledge.

Jan 1, 1945

By H. E. McKinstry

LIKE nearly everything else, mining geology has been reconverting. Many geologists had been in military and other government service. Many more, with mining companies, had been working primarily toward increasing production from known reserves. All of these are turning now toward their normal peacetime endeavor-the search for new ore; for most mining companies, finding themselves with accumulated deficits in development work, are more than ready to go ahead with their postwar plans made a year or more ago but still stalled at the close of 1945 for lack of man power. These plans include not merely development in the old home camp but also wide exploration for new prospects both domestic and foreign. Most of the large concerns have geologists and engineers in the field in the United States, despite the outlook for higher mining costs here, and at least half a dozen strong American companies are already investigating opportunities abroad, notwithstanding past unhappy experiences in certain Latin-American nations which have welcomed capital but later found means of preventing investors from reaping the reward of their enterprise. A few of these new foreign expeditions are following well-planned programs, but too many, in their haste to get any sort of footing, are proceeding without well-considered policy. with the result that their geologists can do little more than desultory scouting.

Jan 1, 1946

By Clarence F. Zeuch

Mr. Shaw&apos;s work showed the dodecyl mercaptan as a very good collector compared with other collectors on Cu-Mo ores, Mo ores, and for Au and Au-Ag ores plus Pt ores. However, as one who has had extensive experience on Cu-Mo ores, the work is not complete in making only a rougher concentrate with a collector; the work must be carried on in making a Cu-Mo separation. Did Mr. Shaw do any of this work? Before trying the dodecyl mercaptan as a Cu-Mo collector for the Cu-Mo ore it would be well to have any new work conducted knowing how the reagent acts on the Mo. Will it allow a good separation? The use of the collector at Palabora was also mentioned. From some earlier literature I thought that the reagent has been used as an oxide Cu collector after the sulfide mineral was floated out. I thought the pH at this point was about 1.5-3.0. I would like to have this point clarified.

Jan 1, 1982

By G. W. Josephson

VIRTUALLY every year inventors find one or more startling new uses for one of the varied products of the nonmetallic mineral industries. For example, in November a major step toward positive control of rainfall was made when an experimenter converted a cloud to snow by dropping a few pounds of solid carbon dioxide into it. Other examples of ingenuity in the development of markets and production methods are noted in the following pages. For most of the industrial mineral products one of the outstanding features of 1946 has been the high level of production. There are exceptions, such as quartz crystal and lithium, whose production capacity during the war outgrew current peacetime needs, but they are few. Some technical men point out that this prosperity is not an unmixed blessing to technologic progress, because so much effort must go into day-to-day production problems that relatively little opportunity is left for the pursuit of new developments.

Jan 1, 1947

By AIME AIME

BY the end of 1943, the United States will be able to produce aluminum at a rate of 1,150,000 tons a year. How much aluminum is 1,150,000 tons? It is sufficient to replace every railroad passenger car in this country three times a year. Or, it would put a thirty-piece aluminum cooking utensil set in every one of America&apos;s 34,000,000 homes with enough metal left over to make 5,000,000 miles of aluminum transmission cable, such as was used in the electrification of much of rural America. Expansion of aluminum production capacity for the war program has occurred in three steps: (1) expansion by private industry; (2) the letting of contracts by the Defense Plant Corp. for the construction of additional aluminum plants which may remain after the war to compete with existing facilities; and (3) the more recently announced D.P.C. program for the building of emergency plants to make aluminum, using stand-by power available in large metropolitan centers power of relatively higher cost, making it questionable whether such plants, now gravely needed, will be able to compete in a peacetime economy.

Jan 1, 1943