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By H. Cecil Spicer

The results described in this article are based On field work conducted during the periods April-May, I939, and May-July, 1940. The United States Potash Co. is mining potash on Government land under a permit from the Department Of the Interior and the geophysical investigation was completed under a cooperative arrangemerit made between that company and the Conservation Branch Of the Geological Survey. The writer, a member Of the SeCtion of Chemistry and Physics of the Geologic Branch, was assigned to this investigation. Four definite objectives were in mind for the geophysical work in the studies over the salt deposits. The first was to determine the measure Of success that could be attained in this type of work with the resistivity methods that were to be employed. These methods had been introduced into the work of the Conservation Branch by Benjamin E. Jones for the investigation of dam sites, and have been used under his direction by the author for such work. If the method proved to be be an effort was to be made to contour the top of the salt beds and also the other formation boundaries known to be present in this area. Salt-water aquifers were to be studied in an effort to determine their boundaries, and an attempt was to be made to delineate the potash-bearing beds. Earlier Studies Others have made, and reported, restivity studies over saliferous deposits in different areas. Friedell and Messrs. Schlumberger2 reported geophysical work performed in the discovery of the salt domes of Alsace; Carrette and Kelly? described the geology of the same area. Leonardon and Kelly' published a resistivity curve obtained over the Hettenschlag dome, and a further discussion of this same area was given by the Messrs. Schlumberger6 in a communication. Messrs. Alty6 described studies on salt deposits in which the single-probe method was used. sinerez7 mentions that electrical methods were tried over salt deposits in Spain. Geoffrey and Charrin8 show a resistivity curve obtained over marl, gypsiferous marl and salt which is similar to that obtained over the New Mexico salt deposits. Kelly9 reported resistivity work performed with the ground Comparaor of Zuschlag over the salt deposits near Syracuse, N. Y., where the Salina formation is at a depth of 700 to 800 ft. Some structural studies on the potash basin of Alsace are described by Poldini.10 Another single-probe resistivity study, made over salt deposits in New Mexico, is briefly described by Heiland,11 through the courtesy of Harry Aurand, of the Midwest Refining co, Geological Features OF Area Covered The area discussed in this paper is in Eddy County, southeastern New Mexico, a

Jan 1, 1946

By Samuel E. Doak

The utilization of rotary kilns, of the well-known cement type, for the preparation of iron ores for the blast furnace, has become of considerable economic importance within the past 10 years in certain localities, notably those where the native ores are lean. Such kilns may be used simply for the agglomeration of ores too fine to be charged into the blast furnace (i.e., ores whose, loss in the dust catchers is excessive, and whose fineness is detrimental to the working of the furnace), or for the desulphurization of lump and fine ores the sulphur content of which does not exceed 6 or 7 per cent. The desulphurizing action can be combined with that of agglomeration provided the kiln is sufficiently large. Other processes have been developed for the same purpose, but while I am not able to draw a comparison between them by reason of lack of sufficient data, it is safe to say that the kiln, if properly dimensioned for the character of ore to be treated, will compare favorably in its results, both as to economy and quality of product, with any other process. It is not, however, as well adapted for the treatment of flue dust as is a sintering operation, on account of the large percentage of fine coke contained therein. Any combustible entering the kiln at its feed end renders the process very much more expensive and unsatisfactory on account of the difficulty of controlling the temperature, also because of the rapidity with which long "rings" form, due to the increased heat at the cooler end of the kiln. The greatest value of the kiln at present is in the treatment of pyrites cinder; that is, the residue from pyrites ore after the extraction of the greater part of the sulphur. This cinder, while high in iron content, has too much sulphur remaining in it to be allowed to form a large part of the blast-furnace burden, without further treatment. It will range in metallic iron from 42 per cent., representing a very low-grade cinder from a domestic pyrites, to 64 per cent. of the residue from the best Spanish ore, and the corresponding silica content will vary from the maximum of about 25 per cent. to 11/2 per cent. The residual sulphur depends largely on the type of burner used in the original desulphurization. In general, the leanest original ores retain the greatest amounts of sulphur. In modern practice the percentage of sulphur in the cinder is rarely as great as six, and seldom lower than one and one-half. Average analyses for iron, silica, and sulphur of the cinders that have come under my personal observation are as follows:

Jan 1, 1916

By Herbert H. Kellogg

In 1930, Taggart, Taylor and Knoll1 found that addition of various electrolytes to suspensions of ground minerals resulted in the stopping or starting of Brownian movement of the suspended particles. On the basis of the many new facts found, they rejected the " classical"† theory of Brownian movement and proposed an "ioniza-tion " theory. This new theory was further supported in later publications by Taggart.3,4 The acceptance of the ionization theory by men in the field of flotation may be judged by the mention given this theory in Gaudin's "Principles of Mineral Dressing,'16 Wark's "Principles of Flotation,"8 as well as in a recent paper by Fitt, Thomas and Taggart.7 The proponents of the ionization theory have gone further than the mere statement of the new theory. A parallelism between the Brownian movement of mineral particles and their behavior in flotation was reported.1,3,4 Likewise, the correlation between flocculation-dispersion of mineral particles and the Brownian movement of these particles has been investigated.' Bankoffl5 has suggested that "slime-coating" can also be directly correlated with the Brownian movement of the slime particles. In each of the instances mentioned it is the ionization theory of Brownian movement that has been used to "explain" the correlations that were found. The essential conflict between the kinetic theory and the ionization theory can be understood best by a brief description of each. The kinetic theory* proposes that Brownian movement is caused by the impacts of liquid molecules against the solid particles. At any instant of time, the molecular impacts on all sides of the solid particle will not balance, and the particle will receive a push in some direction. According to this theory, dl particles suspended in a liquid are in Brownian movement. However, if the particle is very large, the impacts on all sides will very nearly balance and the motion will not be noticeable. Another factor, besides the size of the particle, that affects the magnitude of the Brownian movement is the viscosity of the liquid—the greater the viscosity, the less the displacement of particles by Brownian movement. This theory has been verified experimentally by measurement of the velocity of Brownian movement, and by measurement of the compacting of suspensoid particles under the influence of gravity.2 The originators of the ionization theory found that he addition of various electrolytes to slime pulps caused cessation or commencement of Brownian movement, depending upon the chemical nature of the particle and the electrolyte. The Brownian movement of quartz particles was observed to stop upon the addition of Certain electrolytes, where the conditions of the experiment prevented flocculation

Jan 1, 1947

By Herbert H. Kellogg

In 1930, Taggart, Taylor and Knoll1 found that addition of various electrolytes to suspensions of ground minerals resulted in the stopping or starting of Brownian movement of the suspended particles. On the basis of the many new facts found, they rejected the " classical"† theory of Brownian movement and proposed an "ioniza-tion " theory. This new theory was further supported in later publications by Taggart.3,4 The acceptance of the ionization theory by men in the field of flotation may be judged by the mention given this theory in Gaudin's "Principles of Mineral Dressing,'16 Wark's "Principles of Flotation,"8 as well as in a recent paper by Fitt, Thomas and Taggart.7 The proponents of the ionization theory have gone further than the mere statement of the new theory. A parallelism between the Brownian movement of mineral particles and their behavior in flotation was reported.1,3,4 Likewise, the correlation between flocculation-dispersion of mineral particles and the Brownian movement of these particles has been investigated.' Bankoffl5 has suggested that "slime-coating" can also be directly correlated with the Brownian movement of the slime particles. In each of the instances mentioned it is the ionization theory of Brownian movement that has been used to "explain" the correlations that were found. The essential conflict between the kinetic theory and the ionization theory can be understood best by a brief description of each. The kinetic theory* proposes that Brownian movement is caused by the impacts of liquid molecules against the solid particles. At any instant of time, the molecular impacts on all sides of the solid particle will not balance, and the particle will receive a push in some direction. According to this theory, dl particles suspended in a liquid are in Brownian movement. However, if the particle is very large, the impacts on all sides will very nearly balance and the motion will not be noticeable. Another factor, besides the size of the particle, that affects the magnitude of the Brownian movement is the viscosity of the liquid—the greater the viscosity, the less the displacement of particles by Brownian movement. This theory has been verified experimentally by measurement of the velocity of Brownian movement, and by measurement of the compacting of suspensoid particles under the influence of gravity.2 The originators of the ionization theory found that he addition of various electrolytes to slime pulps caused cessation or commencement of Brownian movement, depending upon the chemical nature of the particle and the electrolyte. The Brownian movement of quartz particles was observed to stop upon the addition of Certain electrolytes, where the conditions of the experiment prevented flocculation

Jan 1, 1947

By Henry S. Drinker

THE Butler Mine property is situated in the vicinity of Pittston, in the Wyoming coal-field of Pennsylvania. The coal has been worked out from the fourteen-foot or Baltimore vein for a number of years on part of the tract, the old chambers remaining open as when originally abandoned. This vein outcrops on the Butler property, and is nowhere more than sixty feet below the surface of the ground on the line of the cut-off to be described. Above the fourteen-foot vein and about, say midway, between it and the surface of the ground, there is another small vein or rider of coal, about twelve inches in thickness. The rock between the two veins is a carbonaceous slate, about twenty-five feet in thickness. Above the smaller vein is a bed of sandstone, varying in thickness, but generally not less than from eight to ten feet. This sandstone is also carbonaceous, but the proportion of carbon is much less than in the slate below. Both rocks have been analyzed, and before the next Institute meeting, the writer hopes to be able to furnish the exact proportions. The sandstone is overlaid with debris up to the surface of the ground. Some time during the spring of 1876, it was found that the coal left in the worked-out mine had been set on fire, and that the fire was gradually spreading. Inquiry developed the fact that the fire had originally been started by a woman, who had taken up her abode in an old tunnel leading into the workings. Owing to some delay in the early attempts made to extinguish the fire, it finally gained such headway that no ordinary means were found to be effectual. Finally, Mr. C. F. Conrad, civil and mining engineer, of Pittston, Penna., was called in as consulting engineer. He advised the making of a thorough cut through such portion of the old workings as had not been reached by the fire. It was found by survey that this cut could be limited to a length of about one thousand two hundred feet, as the vein faulted on both sides, and that the greatest depth of the cut would be about sixty feet. Subsequently it was decided to tunnel part of the way, thus saving the deepest portion of the cut. In 1856-7, there occurred a fire in the same mine. Two stone-walls in V-shape running from the apex of the V towards the outcrop, were built to cut the fire off, and these walls were carried as far as the vein had at that time been worked. After the walls were finished

Jan 1, 1879

By Eric Kula, Åke Josefsson

L. J. Dijkstra and R. Sladek, (Ontario Research Foundation, Toronto, and Institute for the Study of Metals, Chicago, respectively)—This interesting paper confirms some results obtained some years ago in collaboration with Fast: namely the broadening of the nitrogen peak by the presence of small amounts of manganese. Later on a more extensive study of this effect was made at the Institute for the Study of Metals at Chicago. As the work has not yet been submitted for publication we wish to mention here briefly some of the results. The effect of about 0.5 atomic pct manganese, chromium, molybdenum, or vanadium on the nitrogen-peak in iron was examined. The broadening found previously in the case of manganese was even found to be more pronounced for chromium. In the case of molybdenum and vanadium a double peak was observed which seemed to justify the idea that in all cases mainly two relaxation times were involved: namely, the normal relaxation time as found in pure iron and a second relaxation time related to the existence of abnormal interstitial lattice sites introduced by the foreign metallic element. The analysis showed that for the normal nitrogen-peak as a reference at 22°C the abnormal peak was found at about 32°, 47°, 75°, and 87°C in the case of manganese, chromium, molybdenum, and vanadium, respestively. In the manganese alloy the free energy difference for a nitrogen-atom at an abnormal and a normal lattice site was estimated at 2800 cal per mol. This means that for temperatures above 100°C the solid solubility and overall diffusion rate of nitrogen is not much affected by additions of 0.5 pct Mn. We believe that the difference in rate of precipitation of nitrogen in pure iron and the manganese alloy is mainly a question of the number of potential nuclei available in the different steels. In studying the effect of these alloying elements on precipitation of nitrogen, a distinction must be made between the para reaction and ortho reaction, using terminology introduced by Hultgren.7 The ortho reaction in which the alloying metallic element participates in the diffusion under formation of nitrides occurs at high temperatures such as 600°C. The para reaction in which the alloying metallic element does not diffuse and in which the nitride inherits its alloy content from the matrix occurs at lower temperatures. To prevent the ortho reaction the alloys have to be quenched rapidly from the phase. It is not surprising that the authors find that the height of the peak indicates a lower nitrogen content than chemical analysis. In the first place the peak is not a single relaxation peak and secondly, the steels were not quenched from the phase after the nitrogen was introduced at 580 °C.

Jan 1, 1953

By Henry S. Drinker

The Butler Mine property is situated in the vicinity of Pittston, in the Wyoming coal-field of Pennsylvania. The coal has been ' worked out from the fourteen-foot or Baltimore vein for a number of years on part of the tract, the old chambers remaining open as when originally abandoned. This vein outcrops on the Butler prop erty, and is nowhere more than sixty feet below the surface of the ground on the line of the cut-off to be described. Above the four teen-foot vein and about, say midway, between it and the surface of the ground, there is another small vein or rider of coal, about twelve inches in thickness. The rock between the two veins is a carbon aceous slate, about twenty-five feet in thickness. Above the smaller vein is a bed of sandstone, varying in thickness, but generally not less than from eight to ten feet. This sandstone is also carbonaceous, but the proportion of carbon is much less than in the slate below. Both rocks have been analyzed, and before the next Institute meet ing, the writer hopes to be able to furnish the exact proportions. The sandstone is overlaid with debris up to the surface of the ground. Some time during the spring of 1876, it was found that the coal left in the worked-out mine had been set on fire, and that the fire was gradually spreading. Inquiry developed the fact that the fire had originally been started by a woman, who had taken up her abode in an old tunnel leading into the workings. Owing to some delay in the early attempts made to extinguish the fire, it finally gained such headway that no ordinary means were found to be effectual. Finally, Mr. C. F. Conrad, civil and mining engineer, of Pittston, Penna., was called in as consulting engineer. He advised the making of a thorough cut through such portion of the old workings as had not been reached by the fire. It was found by survey that this cut could be limited to a length of about one thousand two hundred feet, as the vein faulted on both sides, and that the greatest depth of the cut would be about sixty feet. Subsequently it was decided to tunnel part of the way, thus saving the deepest portion of the cut. In 1856-7, there occurred a fire in the same mine. Two stone walls in V-shape running from the apex of the V towards the out crop, were built to cot the fire 06 and these walls were carried as far as the vein had at that time been worked. After the walls were finished

Jan 1, 1879

By Thomas F. Donnelly

Discussion of the paper of THOMAS F. DONNELLY, presented at the San Francisco meeting, September, 1915, and printed in Bulletin No. 104, August, 1915, pp. 1759 to 1768. F. LYNWOOD GARRISON, Philadelphia, Pa. (communication to the Secretary *).-The paper is of value in giving the public some first-hand information regarding a copper property that from various causes has attracted considerable attention, especially in Philadelphia, and which has also been the source of several fantastic flotations that had little to recommend them. Since 1906, no work has been done on this property under my direction, with the exception of a topographic survey made last winter by Mr. Donnelly, which was intended as the first step in a sound and logical system of development. From 1906 to 1915, desultory attempts were made to develop these orebodies, but as the work was not in competent hands much money was wasted and even more disappeared in ways regarding which it is perhaps not best to inquire. The result is, this interesting property has now practically no more ore developed upon it than in 1906, despite the fact that a new 100-ton mill is being erected, although, as I have intimated, it is today not much more than a prospect. Turning now to the scientific and more agreeable side of the subject, it is interesting to note that these Santo Domingo copper ores are invariably found in volcanic tuffs and that, in a geologic sense, they are all very old, for there are no evidences of recent volcanic activity in the greater Antilles, of which this island is the second largest. The existence of copper in tuffs in different parts of the world is a notable fact. Often, if not usually, it is present in mere traces, but not infrequently we find it in sufficient amount to be of economic importance. Thus, for example, chalcopyrite and bornite occur in the Tertiary tuffs of Japan, and a number of producing copper mines of that country are either actually in, or closely associated with, rocks of this character. Whether the copper minerals are original primary ores in the tuffs, or were derived from accompanying eruptive dikes, appears not yet to have been determined in any instance. In most of the Japanese cases of which I can find any record the tuffs appear to be associated with shales and limestones. These Japanese copper ores also carry some gold, especially in the upper parts of the veins; in this they resemble the Santo Domingo deposits which not infrequently carry as much as $6 or $7 per ton of gold on the outcrop. As a rule the content of gold in both the Japanese and

Jan 12, 1915

JOHN W. BELL (communication to the Secretary*).-I have to thank Mr. Merrill not only for his very kind remarks, but for the weight of his implied opinion that the work accomplished probably has an important practical aspect. I think there is a distinct although unuttered impression among engineers, that it will be time enough for them to begin to take an interest in the law of crushing when it emerges from the cloud of violent and even vituperative controversy that has hovered over it during the last 6 or 7 years. I have a very confident feeling that as the result of the work done by Mr. Gates, by me and by Messrs. Mitchell, Baily and Cockfield, who so loyally helped me to obtain the necessary data, at least the practical law of crushing has emerged; that it is ready and available for use by our fellow engineers, and that it will help them to unravel a number of the many practical problems they are con¬stantly confronted with. In regard to Mr. Gates' discussion, I would indeed like to believe that McGill could claim, as a minor achievement, the credit which Mr. Gates so generously bestows of having established the "law" of crushing. I think that more work would be required to establish this claim in the, strict sense of the word, as there is a fairly large gap between the coarse and fine crushing results. I am not worried about that gap, because the reason for it is quite clear to me; at the same time I-think it will be well to bridge it by a series of tests, and I am bound to admit that the testing machine is the most promising machine right at hand to work with, although whether the minute amounts of power required to crush small quantities of rock can be so accurately integrated as to insure high accuracy in the final result is still a question in my mind. If we had an Amsler-Laffon machine I would certainly try it. Mr. Gates' remarks about choke crushing are extremely interesting. He compels me to wonder, too. It is a new and probably a very important factor to be considered in this connection. I am in perfect accord with Mr. Gates about the desirability of the determination of crushing constants, because when this is accomplished the efficiencies (not relative mechanical, but real efficiencies) of different types of rock-crushing plants in any part of the world will then be comparable. For this reason it would, seem desirable that the American Institute Committee should not only consider ways and means for accom-

Jan 6, 1917

By L. D. Ricketts

Discussion of the paper of L. D. RICKETTS, presented at the San Francisco meeting, September, 1915, and printed in Bulletin No. 100, April, 1915, pp. 711 to 737. FREDERICK LAIST, Anaconda, Mont.-I am going to tell you of some of the results we have been getting in Anaconda during the past two or three months in a large plant which was finished in May. We commenced work in Anaconda a year and a half ago on the construction of a leaching plant which was to have a capacity of 2,000 tons per day. The plant was to treat tailings from the concentrator, containing about 12 1b. of copper to the ton. During the past year we changed our plans and decided to use the flotation process on the tailings from the concentrator, which contained no oxidized copper, and apply the leaching process only to tailings which had accumulated in a large dump below the works. This dump contains about 15,000,000 tons of tailings, and since some of the copper in it is oxidized, we felt that the application of the flotation process would result in the loss of too much of the oxidized copper, particularly as time went on. In starting up we had a number of difficulties to overcome, as is usually the case. They were not of a serious character. The results obtained, so far, have been decidedly encouraging. During July the plant treated a total of 50,000 tons of tailings, or an average of 1,610 tons per clay. The extraction was about 83 per cent., which, on material of the grade treated, meant a. tailing assaying under 0.1 per cent. copper. The acid consumption was about 65 lb. per ton, and the fuel percentage in. roasting was about 4 ¼ . We expect to cut the fuel percentage in the next month or two to about 3 per cent., the high percentage during July being clue to starting up and shutting clown furnaces. We find that iron builds up in the solution to a marked degree. This is not a serious platter with us, because we have cheap sulphuric acid and can reject solution whenever it gets too foul. The extraction of silver has been remarkably good in the large plant. It has averaged better than 75 per cent. It seems that so long as we maintain salt in the solution to a percentage of 10 per cent., the extraction is good. We allowed the salt to fall off in order to find how low a percentage we could use. At about 7 per cent. the silver extraction fell to 65 per cent. This was to be expected, because silver chloride is soluble in strong brine, but not in weak brine.

Jan 12, 1915

By A. Kenneth Schellinger, O. Cutler Shepard

INTRODUCTION OVERGRINDING, or the breaking of ore particles into sizes smaller than required for liberation, is a first-magnitude problem in grinding for concentration processes. The conventional ball mill-classifier circuit used in commercial grinding produces mineral particles that are all ground to pass an upper size limit, while the proportion of very fine sizes, or slimes, is uncontrolled. Calculations based on measurements made in commercial plants which were grinding ore for flotation concentration indicate that about 90 pct of the energy used in grinding is consumed in useless overgrinding.1 In addition to accounting for the consumption of a large amount of energy, overgrinding is detrimental to the flotation process. Overground slime coats larger particles and inhibits selective action by the flotation reagents on particles which by themselves could be separated very well. A further difficulty is that extremely finely ground minerals do not respond satisfactorily to flotation-collecting reagents, and both selection and recovery decrease markedly with particles finer than 5 to 10 microns.2 Conventional classifier-ball mill circuits inherently tend to overgrind the valuable minerals more than the gangue minerals because most valuable minerals are of higher density and are softer and more friable than the gangue minerals. The remedy to this situation would seem to be a separating mechanism which would separate free valuable mineral particles regardless of size and density considerations and a mechanism which would operate in the grinding mill so that valuable mineral grains would be removed from the grinding machine as soon as they are freed. A consideration of these ideas led the authors to the conception of a simultaneous grinding and flotation mechanism. So far as the authors are aware, such a machine has never been tried, even on a laboratory scale. DEVELOPMENT OF APPARATUS AND EXPERIMENTAL METHOD Apparatus development went through several stages before a really workable machine was devised. Work was started with a large cast-iron mortar 7 ½ in. in diameter and 8 in. deep. A cast-iron disk was mounted on the end of a vertical shaft so that it fitted loosely into the bottom of the mortar. On top of the disk four radial cleats ¼ in. high were bolted to agitate the ball charge as the disk, or impeller, rotated. The vertical shaft was driven at 100 rpm by a mechanism improvised from an old coffeemill type of grinder. A hole was drilled into the bottom of the mortar through which compressed air was introduced for frothing. In operation, weighed charges of ore which had been crushed to pass an 8-mesh screen were placed in the bowl along with water and suitable reagents. The impeller was then started and the compressed air turned on so that the ore was ground while being exposed to air bubbles. Mineralized froth was

Jan 1, 1947

By J. G. Giddings, R. Kobayashi

Residual viscosity, the ViSCOSitY at a given pressure and temperature minus the dilute gas viscosity at the same temperature, has been found to be independent of temperature for pure components and mixtures for simple molecules and light hydrocarbons. The residual viscosities for methane, ethane, propane and four mixtures were correlated as a function of reduced density and molecular weight. INTRODUCTION Earlier efforts in correlating the viscosity of light hydrocarbons and associated gases under pressure, primarily by some form of the corresponding states principle, have been reported elsewhere.7 The formal theory of corresponding states principle for viscosity from non-equilibrium statistical mechanical arguments for simple molecules has been developed by Helfand and Rice.13 The most serious obstacle to the development of a generalized corresponding states representation of viscosity data, even for simple molecules, has been the limited quantity of precise viscosity data of pure components and mixtures over a wide range of pressure and temperature conditions. Viscosity data on light hydrocarbons have recently been contributed by several laboratories.2,6,8,23,25,26 In the study of the viscosity of nitrogen, Michels and Gibson" observed that the viscosities of nitrogen as a function of density gave parallel isotherms. The same behavior has since been reported for other gases.".= The observed behavior indicates that the residual viscosity or the viscosity at a given pressure and temperature minus the dilute gas viscosity at the same temperature is a unique function of the density. Abas-Zade,1 Michels and Botzen,18 and Michels, Bot-Zen, Friedman and Sengers,19 observed similar behavior for thermal conductivity, the residual thermal conductivity being defined in a manner parallel to that of residual viscosity. Thodos and co-workers 4,15,24 applied the residual viscosity concept to the viscosity of pure monatomic and diatomic gases. Ellington and co-workers10,25 made the residual viscosity vs density plots for ethane and propane, but omitted the region below a residual viscosity of 15 micropoise and showed a systematic separation of the ethane isotherms in the low density region. Eakin correlated the residual viscosity of methane, ethane, propane and n-butane empirically as a function of density and molecular weight: Carmichael and Sage6 recently presented ethane residual viscosity vs density values in the gaseous liquid, and near critical regions as a single univariant function of density. Flynn, Hanks, Lemaire and ROSS" have contributed extremely accurate viscosity data to confirm that the residual viscosity concept is essentially correct, but may not be accurate within 0.1 per cent of the viscosity value for the gaseous state- The recent studies by Giddings12 indicate that the residual viscosity of methane, propane and each of four methane-propane mixtures are unique functions of density Over the temperature and the density ranges studied.

Jan 1, 1965

By Tell Ertl, Ernest E. Burgh

The Bureau of Mines is operating an oil-shale mine 10 miles west of Rifle, Colo., as part of its Synthetic Liquid Fuels program. The purpose of operating this mine is twofold: First, to supply oil shale to an experimental Processing plant; and second, to develop practices and select methods for mining oil shale on a commercial scale at the lowest practicable cost. The second purpose—that of finding out how to mine oil shale most cheaply—entails considerable mining research. Since the drilling of oil shale probably will be one of the major items of the mining cost, fattors that influence drilling speeds were investigated. One phase of the drilling program was the development of a successful hard-surfaced rock-drill bit1 that can be used for drilling long holes in oil shale without changing bits. During that phase, drilling speeds were measured and drill cuttings were collected for assay and for screen sizing, when the cuttings from the individual tests were compared, a definite relationship was shown to exist between the drilling speed and the coarseness of the drill cuttings. Procedure Measurement of Drilling Speeds All drilling in the tests was done with a Model UMB-D-99W Gardner-Denver wagon drill. Round-lugged drill steel, 141 in. in diameter was used in 6, 12, and 18 ft lengths with 1/8-in. Timken H-type bits hard-faced with acetylene tube borium. The tests were made in the lower adit of the Bureau of Mines oil-shale mine; the grade of the oil shale drilled ranged from 18.6 to 42.7 gal per ton, During the experiments air pressure varied between 75 and go psi while water pressure remained fairly constant at 75 psi. All holes were drilled almost horizontally. Each drill hole was thoroughly cleaned of cuttings after being collared. The advance of the drill along the carriage was measured and recorded as the drilling speed in inches per minute. Method of Collecting Cuttings TO facilitate the collection of cuttings, each drill hole was collared in a smooth, vertical portion of the oil-shale breast (Fig 1). A galvanized-stee1 sheet was fastened to the breast below the area in which the hole was to be drilled. The cuttings washed out of the drill hole by the drilling water were guided by the steel sheet into a wooden box. The cuttings that remained in the drill hole after the drill was withdrawn were scraped out and placed in the same box as the cuttings washed out of the hole. After the cuttings from a I-min. drilling interval were collected, they were placed in flat metal pans. The fines were allowed to settle and the clear water was decanted. The cuttings then were dried in the sun.

Jan 1, 1949

By J. D. Clark

ONE'S lifetime does not usually offer the oppor-tunity to observe and be a part of the commercial development of an entirely new material. Petalite has been known for over a century, but at first it was presumed rare. However, it was found to be so abundant that it has become a new and extremely useful industrial tool. Mineralogy Petalite is a lithium-aluminum-silicate mineral. It was from petalite that J. A. Arfwedson first discovered lithium in 1818. The theoretical composition of Li2O • A12O8 • 8SiO2 is equivalent to 78.4 pct silica, 16.7 pct alumina and 4.9 pct lithia. The mineral in its known commercial occurrence is colorless to white and rarely gray, transluscent and rarely transparent. It is brittle, has a vitreous luster, and occurs usually in cleavable masses (fig. 1). It is classified as a di-silicate, but is similar in composition to the metasilicate spodumene, Li2O.-Al2O8-4SiO2 (table I). However, their specific gravities are quite different (3.13 to 3.20 for spodumene, 2.39 to 2.46 for petalite). Occurrence Petalite specimens have been reported in many localities; however, there are only three known countries having occurrences of commercial significance. The classic locality is Sweden's Utö Mines, which, although reportedly still containing considerable petalite, have been closed and are not expected to be operated in the near future. At Varuträsk, in northern Sweden, petalite carrying 4 pct lithium oxide is the main ore. In 1946 there was reported about 1000 tons on hand. However, the iron content was 0.60 pet too high for other than chemical use. Petalite has been reported in western Australia. At the Cottesloe mine, where small quantities have been reported available, it is produced in conjunction with feldspar. Petalite occurs in considerable quantity in the feldspar quarry at Londonderry, and it was estimated1 in 1943 that over 3700 tons might be available. The petalite in South West Africa was first discovered by F. J. Jooste, a lawyer by profession, in 1938. The following year he discovered a much larger deposit, and in 1948 another important discovery was made. These deposits occur near Kari-bib and constitute the only known commercial deposits. Their full extent has not yet been determined, but huge massive blocks of petalite of the purest grade, running into many thousands of tons, can be seen in all these deposits. To date, 60,000 tons of high grade, low iron containing ore has been blocked out in the major bodies. Mining for years to come will be confined to simple quarrying. Selection from accessory minerals has proved

Jan 1, 1951

By J. D. Clark

ONE'S lifetime does not usually offer the oppor-tunity to observe and be a part of the commercial development of an entirely new material. Petalite has been known for over a century, but at first it was presumed rare. However, it was found to be so abundant that it has become a new and extremely useful industrial tool. Mineralogy Petalite is a lithium-aluminum-silicate mineral. It was from petalite that J. A. Arfwedson first discovered lithium in 1818. The theoretical composition of Li2O • A12O8 • 8SiO2 is equivalent to 78.4 pct silica, 16.7 pct alumina and 4.9 pct lithia. The mineral in its known commercial occurrence is colorless to white and rarely gray, transluscent and rarely transparent. It is brittle, has a vitreous luster, and occurs usually in cleavable masses (fig. 1). It is classified as a di-silicate, but is similar in composition to the metasilicate spodumene, Li2O.-Al2O8-4SiO2 (table I). However, their specific gravities are quite different (3.13 to 3.20 for spodumene, 2.39 to 2.46 for petalite). Occurrence Petalite specimens have been reported in many localities; however, there are only three known countries having occurrences of commercial significance. The classic locality is Sweden's Utö Mines, which, although reportedly still containing considerable petalite, have been closed and are not expected to be operated in the near future. At Varuträsk, in northern Sweden, petalite carrying 4 pct lithium oxide is the main ore. In 1946 there was reported about 1000 tons on hand. However, the iron content was 0.60 pet too high for other than chemical use. Petalite has been reported in western Australia. At the Cottesloe mine, where small quantities have been reported available, it is produced in conjunction with feldspar. Petalite occurs in considerable quantity in the feldspar quarry at Londonderry, and it was estimated1 in 1943 that over 3700 tons might be available. The petalite in South West Africa was first discovered by F. J. Jooste, a lawyer by profession, in 1938. The following year he discovered a much larger deposit, and in 1948 another important discovery was made. These deposits occur near Kari-bib and constitute the only known commercial deposits. Their full extent has not yet been determined, but huge massive blocks of petalite of the purest grade, running into many thousands of tons, can be seen in all these deposits. To date, 60,000 tons of high grade, low iron containing ore has been blocked out in the major bodies. Mining for years to come will be confined to simple quarrying. Selection from accessory minerals has proved

Jan 1, 1951

By C. M. Moncrief, B C. Craft

A bentonite-clay drilling mud when treated with tetrasodium pyroarsenate underwent substantially the same reduction in viscosity and water loss as when treated with the complex phosphates. The complex arsenate showed a slightly higher reversion after heating; the other arsenates showed poor viscosity-reducing properties. Introduction During the past 10 years the chemical control of drilling mud has become of major importance in affecting the successful drilling and working over of wells. The desired properties of drilling mud have been well established, and in obtaining these characteristics there has developed a large market for viscosity-reducing chemicals. Viscosity reduction produced by humic acid, tannic acid, sodium silicate, sodium tannate, Calgon, and the complex phosphates has been described by Loomis, Ford, and Fidiam.l The effects Of treatment with complex phosphates and ammonium PolyPhosPhates on the rheological properties of muds were investigated by Fancher2 and the alkali vanadates have been described by Williams.3 Laboratory Investigations It is the purpose of this paper to point out the effects of arsenates in controlling the viscosity and gelling characteristics of a drilling mud. Viscosities and gel strengths were measured at room temperatures with a Stormer viscosimeter calibrated in centipoises and operated at 600 r.p.m. Water loss was determined at 80°F. with the Baroid low-pressure wall-building tester at a pressure of I00 lb. per sq. in. for 30 min. The hydrogen-ion concentration was measured with a glass electrode. The bentonite-clay suspensions were prepared in the laboratory and allowed to age several days before testing. Members of the Arsenic Group in the periodic Table include arsenic, antimony and bismuth, but this investigation was limited to arsenic. Phosphorus also occurs in Group V of the Periodic system and phosphorus and arsenic form many closely related compounds such as pH3 and AsH3, P2O5 and As2O5, H3PO4 and H3AS04 Samples of tetrasodium pyroarsenate were prepared by fusing c.p. disodium arsenate (Na2HA5O4.7H2O). According to Friend,' this re-forms the ortho-arsenate on dissolution in water. Sodium trihydrodiorthoarsenate was prepared as described by Mellor,5 from arsenic pen-toxide as follows: As2O5 + 3H20 -> 2H3AsO4 2H3AS04 + 3NaOH Na3H3(AsO4)2 .3H20 Sodium dihydrogen orthoarsenateWaHz-As04) was obtained by fusing together equivalent quantities of arsenious Oxide and sodium nitrate, dissolving the residue in water and allowing it to crystallize.

Jan 1, 1946

By A. P. Cohen, D. W. Fuerstenau

Methods of accounting for the feed size in analyzing the size distribution shift during comminution have been discussed in a number of papers.1,2,3 Based on experiments which charles2 performed with single Pyrex specimens, Schuhmann4 pointed out that the size modulus of an assembly of particles should be determined by the energy expended per unit volume (or mass), independent of the size of particle being comminuted. In this same paper, Schuhmann derived the Charles energy-size reduction relationship by considering that complex comminution operations can be considered to be the summation of many individual comminution events, each of which must be governed by Were 6wi is the mass of a particle receiving the impact, 6Ei is the energy delivered to the particle, ki is the size modulus of the product resulting from the impact, a is the distribution modulus of the assembly of particles, and A is a constant. Recent experiments on the compression loading of Pyrex spheres ranging in size from 1/8 to l-in. diam have shown that the size modulus of the fragments is determined by the strain energy at fracture per unit mass, independent of sphere diameter.' The objective of the present investigation has been to determine experimentally whether the size distribution of the product from such a complex comminution process as rod milling is determined only by the energy expended per unit mass independent of feed size. Samples of each Tyler sieve fraction ranging from 4x6 to 48x65 mesh were prepared from crushed Brazilian quartz crystals. One kilogram of each fraction was ground at 60 pct solids in an 8x9 1/4-in. mill containing 17.5 kg of rods (26 rods, 5/8-in.; 10 rods, 3/4-in.; and 5 rods, 7/8-in. diam). In each test, the mill was run at 77 rpm for 15 min. Size distributions were determined by a wet-dry sieving technique. Table I presents the size distribution of the products obtained by grinding each of the size fractions. Because the size distributions are so nearly alike, they are plotted in Fig. 1 by shifting each size distribution for the different feed sizes one screen fraction to the right. Thus, the lowest point in each size distribution represents 400 mesh and each of the other sieve sizes must be shifted accordingly. A single regression line was calculated by combining the data for the six tests, excluding the coarsest feed and the two finest feed fractions. 6 This regression line, which is given by (Y \0.88 where y is the cumulative percentage of material

Jan 1, 1962

By M. M. Neale

The pottery department has been aptly described as the "heart of the zinc plant," md every operator of a horizontal-retort plant is acquainted with the fact that good retort practice is the keystone of the smelting process. Since retorts and condensers are clay products, it is obvious that improvements in other branches of the ceramic industry should be observed for possible adoption in the pottery process for zinc smelting. Deaeration of clay bodies is one of the improvements that have become fully, established in many brick and pottery plants. Our investigation of a number of these installations always yielded the same answer—improved practice. Improvement in workability, elimination of laminations, less porosity, greater wet and dry strength, were among the claims put forth for this process. All of these features are exceedingly desirable characteristics in the manufacture of a zinc retort. A preliminary test, which involved truck transportation of deaired slugs over a relatively long distance, did show the value of many of these characteristics in forming the retort. Results from the standpoint of , longer retort life in the smelting furnace were not outstanding. The idea lay dormant for several years but was revived again in 1940, when it was decided to make whatever changes were necessary in the equipment for pottery manufacture to fully demonstrate the process. A number of the manu- facturers of machinery for clay work were asked to submit proposals, and the plan finally adopted was extremely simple and economical. Machine FOR DeaeRRATING Selection of the ''Straight-line'' principle for conversion of the "Wettengel" pug mill to a ''vacuum-extrusion" machine preserved some usable parts of the original equipment, such as the drive mechanism, and main shaft. The converted machine consists of a feed hopper, a compression and shredding zone, a vacuum chamber, and an extrusion barrel, as shown in Fig. I. In operation the clay mix travels from the feed hopper into the compression zone, where it is compressed and finally forced around the tapered cone into the vacuum chamber. As it enters this chamber the clay body is shredded into thin plates, for exFosure to the vacuum. The shredder consists of a hub mounted on the main shaft, to which are bolted segmental sections, each of which carries shredder knives. The compression zone and extrusion barrel function as seals for the vacuum chamber and the shredded clay mix is agitated thoroughly during its exposure to the vacuum. A vacuum pump, equipped with a 3-hp. motor, is attached to this chamber, and maintains 25 to 26 in. vacuum during operation of the mill. Changes in Practice Prior to the adoption of the deaeration process, our standard pottery practice called for double mixing in the combination 7

Jan 1, 1944

By C. M. Moncrief

A bentonite-clay drilling mud when treated with tetrasodium pyroarsenate underwent substantially the same reduction in viscosity and water loss as when treated with the complex phosphates. The complex arsenate showed a slightly higher reversion after heating; the other arsenates showed poor viscosity-reducing properties. Introduction During the past 10 years the chemical control of drilling mud has become of major importance in affecting the successful drilling and working over of wells. The desired properties of drilling mud have been well established, and in obtaining these characteristics there has developed a large market for viscosity-reducing chemicals. Viscosity reduction produced by humic acid, tannic acid, sodium silicate, sodium tannate, Calgon, and the complex phosphates has been described by Loomis, Ford, and Fidiam.l The effects Of treatment with complex phosphates and ammonium PolyPhosPhates on the rheological properties of muds were investigated by Fancher2 and the alkali vanadates have been described by Williams.3 Laboratory Investigations It is the purpose of this paper to point out the effects of arsenates in controlling the viscosity and gelling characteristics of a drilling mud. Viscosities and gel strengths were measured at room temperatures with a Stormer viscosimeter calibrated in centipoises and operated at 600 r.p.m. Water loss was determined at 80°F. with the Baroid low-pressure wall-building tester at a pressure of I00 lb. per sq. in. for 30 min. The hydrogen-ion concentration was measured with a glass electrode. The bentonite-clay suspensions were prepared in the laboratory and allowed to age several days before testing. Members of the Arsenic Group in the periodic Table include arsenic, antimony and bismuth, but this investigation was limited to arsenic. Phosphorus also occurs in Group V of the Periodic system and phosphorus and arsenic form many closely related compounds such as pH3 and AsH3, P2O5 and As2O5, H3PO4 and H3AS04 Samples of tetrasodium pyroarsenate were prepared by fusing c.p. disodium arsenate (Na2HA5O4.7H2O). According to Friend,' this re-forms the ortho-arsenate on dissolution in water. Sodium trihydrodiorthoarsenate was prepared as described by Mellor,5 from arsenic pen-toxide as follows: As2O5 + 3H20 -> 2H3AsO4 2H3AS04 + 3NaOH Na3H3(AsO4)2 .3H20 Sodium dihydrogen orthoarsenateWaHz-As04) was obtained by fusing together equivalent quantities of arsenious Oxide and sodium nitrate, dissolving the residue in water and allowing it to crystallize.

Jan 1, 1946

By H. B. Hunter, F. G. Stone, F. J. Dunkerley

Introduction and Literature Survey This is the second in a series of papers coming from this laboratory on the correlation of the low temperature tensile properties of tin-binary alloys with microstructure. These engineering data and those of the previous paper1 were obtained as the initial part of a long-range program to determine the changes in the fundamental mechanical properties accompanying the beta to alpha phase change in tin and its binary alloys below 13.2°C. Since it appears now that the more fundamental studies will be delayed,* and since no summary of the low temperature properties of these tin-base white bearing alloys was found in the literature, it was decided to publish all the engineering data thus far obtained. Accordingly, the tensile properties of thirteen binary alloys containing from 0.1 to 60 pet cadmium and 0.1 to 10.43 pet antimony measured at six temperatures from —196 to +23°C are presented here and their variations rationalized in terms of microstructure. A literature search showed that these systems had not been investigated at low temperatures, although both the tin-cadmium and tin-antimony2,3,4,5 and the tin-rich corner of the ternary system67 have been studied at room temperature. Hanson and Pell-Wal-pole5 and Homer and Plummer4 determined the tensile properties of alloys containing from 0 to 10 pet cadmium. The same authors3 determined the tensile strength and elongation in the tin-antimony system from 2 to 18 pet antimony at room temperature while Pell-Walpole et al.6,7 studied the properties of high tin and tin-antimony-cadmium alloys. Since there were many variables besides composition in these tests, it was difficult to make a valid comparison with the room temperature data of the present study, but in general the tensile strength and ductility values are in reasonable agreement. Pell-Walpole2 also determined the effect of grain size on the tensile strength of pure tin and 1 pet alloys of both antimony and cadmium. The true maximum stress was found to decrease exponentially as the number of grains in the cross-section increased. This effect of grain size was strikingly revealed in the present work, as indicated in a later section. Hanson and Pell-Walpole8 placed the solid solubility limit of antimony in tin at 3.5 pet at 20°C, increasing to 4 pet at 190°C, and then sharply increasing to 10.3 pet at 246°C (the latter being a peritectic point). Their results are in disagreement with those of previous investigators,9 and the discrepancy seems to lie in the micro-graphic observation of the second phase

Jan 1, 1950