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By Paul M. Tyler

Higher freight rates and better methods of beneficiation now may make it more economical to open inferior deposits closer to a glass factory than to work higher-grade deposits farther away. Nature of impurities and special treatments as well as common practice of sulphuric acid leaching are described. HISTORICAL concepts of the economics of the glass-sand industry are changing rapidly. The greatly expanded demand for glass containers combined with higher freight rates on raw materials and manufactured products have induced a migration of glass factories toward densely populated centers and the creation of new standards of place value for substandard sand deposits. This migration has been facilitated by the construction of pipelines to bring cheaper natural gas and liquid fuel to large cities and may be further speeded by the adoption of modern mineral dressing methods to permit economical utilization of local raw materials. Our national resources of naturally high-grade silica sand are abundant, but most of the best deposits are situated so far from large centers of population that it now costs $3.00 to $5.00 a ton to carry the sand from the mine to the optimum site for a factory making beverage bottles, scientific and electrical glassware, and miscellaneous blown and pressed ware for local markets. It follows that on the basis of freight savings alone it may be economical to use material from inferior deposits closer to the factory even though the f.O.b. cost of mining and treatment may be much higher than at a higher grade deposit farther away. Particle-size distribution is a feature of glass-sand specifications. As long as glassmakers insisted upon having their sand principally coarser than 100-mesh, any material was automatically excluded from consideration that could not be purified without fine grinding or other drastic treatment which greatly reduces the size of the quartz grains. However, re- cent large-scale tests in Norway' showed that finely-crushed quartz used in a soda-lime-silica glass batch caused it to melt and become refined appreciably faster than when ordinary coarse (Belgian) sand was employed. Dust losses were negligible. Since the pre-war cost of sand was only 3 pct of the manufacturing cost of the glass, it was deemed economical to pay twice as much for crushed quartz because of the saving in wear and tear on the furnace walls. In the author's unverified opinion, sand ranging in size between 150 and 400-mesh would probably be superior to that in the more usual range of 20 to 100-mesh. Former objections to fine sand (other than dust) were doubtless fostered by the natural concentration of impurities in the finer sizes. Ordinarily the most objectionable, as well as the commonest, impurity from the standpoint of the manufacturer of any but the cheaper qualities of colored glass is iron. No natural sands are really pure silica. Even water-clear quartz crystals are likely to contain impurities in the form of solid solution as well as inclusions which cannot be eliminated except by chemical treatment that will break down the silica lattice. Pure white pegmatite quartz will usually analyze 0.01 pct or more of iron oxide, and ordinary vein quartz and the quartz grains in most

Jan 1, 1951

By Paul M. Tyler

Higher freight rates and better methods of beneficiation now may make it more economical to open inferior deposits closer to a glass factory than to work higher-grade deposits farther away. Nature of impurities and special treatments as well as common practice of sulphuric acid leaching are described. HISTORICAL concepts of the economics of the glass-sand industry are changing rapidly. The greatly expanded demand for glass containers combined with higher freight rates on raw materials and manufactured products have induced a migration of glass factories toward densely populated centers and the creation of new standards of place value for substandard sand deposits. This migration has been facilitated by the construction of pipelines to bring cheaper natural gas and liquid fuel to large cities and may be further speeded by the adoption of modern mineral dressing methods to permit economical utilization of local raw materials. Our national resources of naturally high-grade silica sand are abundant, but most of the best deposits are situated so far from large centers of population that it now costs $3.00 to $5.00 a ton to carry the sand from the mine to the optimum site for a factory making beverage bottles, scientific and electrical glassware, and miscellaneous blown and pressed ware for local markets. It follows that on the basis of freight savings alone it may be economical to use material from inferior deposits closer to the factory even though the f.O.b. cost of mining and treatment may be much higher than at a higher grade deposit farther away. Particle-size distribution is a feature of glass-sand specifications. As long as glassmakers insisted upon having their sand principally coarser than 100-mesh, any material was automatically excluded from consideration that could not be purified without fine grinding or other drastic treatment which greatly reduces the size of the quartz grains. However, re- cent large-scale tests in Norway' showed that finely-crushed quartz used in a soda-lime-silica glass batch caused it to melt and become refined appreciably faster than when ordinary coarse (Belgian) sand was employed. Dust losses were negligible. Since the pre-war cost of sand was only 3 pct of the manufacturing cost of the glass, it was deemed economical to pay twice as much for crushed quartz because of the saving in wear and tear on the furnace walls. In the author's unverified opinion, sand ranging in size between 150 and 400-mesh would probably be superior to that in the more usual range of 20 to 100-mesh. Former objections to fine sand (other than dust) were doubtless fostered by the natural concentration of impurities in the finer sizes. Ordinarily the most objectionable, as well as the commonest, impurity from the standpoint of the manufacturer of any but the cheaper qualities of colored glass is iron. No natural sands are really pure silica. Even water-clear quartz crystals are likely to contain impurities in the form of solid solution as well as inclusions which cannot be eliminated except by chemical treatment that will break down the silica lattice. Pure white pegmatite quartz will usually analyze 0.01 pct or more of iron oxide, and ordinary vein quartz and the quartz grains in most

Jan 1, 1951

By F. Julius Fohs

TAKING into consideration the present state of geologic knowledge and present economic status of the oil industry, we have attempted to outline the six principal districts in which oil occurs and new pools may be expected. The map, Fig. 1, also shows the location of the present productive pools-about 100 in number. The unshaded areas represent territory where drilling depths to known sands are prohibitive with present development and pumping methods, or such sands are absent or give promise of such small production that deep wildcat tests are unwarranted. They include, also, territory where the oil-source materials are absent or not of the right type; and where shales are insufficient in the stratigraphic section to prevent the escape of oil and gas. Some doubtful districts are also included, such as the Pecos Valley, where the percentage of rigid beds, sandstones and limestones may be too great; and the Nacogdoches oil field, where small shallow production is obtained but where deep or large production is unlikely. The map is not offered as final but in the hope that it may prevent the expenditure of large sums in attempted development of unlikely territory and as the warning that those who drill in the unshaded territory do so at great risk. Those who drill in such territory should have large sums available for pioneering and experimenting and only attempt it if they can well afford to lose the money expended. Search in the shaded or cross-hatched areas is hazardous enough and should only be undertaken after detailed geologic surveys. Out of a total area of 256,000 sq. mi., the oil and gas districts comprise about 80,000 sq. mi.; the territory embraced in these districts is shown in the shaded portions. This may ultimately be increased somewhat by the addition of some minor districts, but such additions will be offset by territory probably now included in the unshaded areas. The shaded areas probably contain 98 per cent. or more of the ultimate production of the state, despite the fact that they represent only 31 per cent. of the total area.

Jan 3, 1924

By Oliver Bowles

DELICATE PLANTS are now put to bed for the winter under glass-wool or rock-wool blankets. Thus arise new and unexpected uses for non-metallic materials and rocks and, at the same time, certain unique uses are fading out; for instance, the Italians have taken steps to bar the use of salt for money in Ethiopia. Novel sources of supply find a place in the record of recent achievements as exemplified in the migration of the frontiers of industrial mineral exploitation beyond the land area of the earth to include the ocean. Salt, of course, has been recovered from the sea for years but the treatment of enormous quantities of sea water for bromine has lately added to the importance of the ocean as a reservoir of mineral wealth. Increased use of non-metallic minerals in the commercial and economic life of the country is reflected in the wide scope and activity of the Industrial Minerals Division of the Institute. The outstanding recent achievement of the Division is the publication of a 955-page volume on industrial minerals and rocks, comprising 48 commodity chapters each written by an authority on the subject.

Jan 1, 1938

By Morris Muskat

It is pointed out that the application of capillary pressure curves obtained by drainage or desaturation processes to the calculation of the fluid distribution in interphase transition zones involves a number of difficulties; namely: (I) the development of very low nonwetting phase saturations appears to be in contradiction with the lack of mobility of such distributions indicated by permeability-saturation curves, (2) dispersed nonwetting phases are thermodynamically unstable, and (3) discontinuous phases should not be subject to hydrostatic equilibrium requirements. While these difficulties could be obviated by assuming that the capillary pressure drainage curve has an initial horizontal segment, they are automatically circumvented by application of the imbibition capillary pressure curve to the lower part of the water-oil transition zone. These generally show zero displacement pressure at only partial wetting-phase saturations. The countercurrent upward flow of oil into the main oil-saturated pay and downward drainage of water also suggests that wetting phase imbibition processes will control the saturation distribution immediately above the water-saturated section. Similar considerations, with a generalized interpretation of the apparent wetting-phase behavior of the oil and gas phases, provides a basis for constructing the curve for fluid distribution in the oil-gas transition zone. In the transition zones so derived, the oil begins with a nonvanishing saturation at the water-oil contact and terminates with a similar saturation at the top of the gas-oil contact. The gas-oil transition zone begins with an equivalent nonvanishing gas saturation. Introduction It has been a common assumption for some years that the nature of the fluid dis- tribution in virgin reservoirs, and in particular that in the transition zones between the oil and water and between the oil and gas sections, can be computed by a simple application of capillary pressure data. The results of such calculations appear to have been first reported by Leverett.' The latter, however, indicated only the numerical values of the parameters used in the computations, without explicitly describing the procedure. Leverett's illustrative calculated transition zones are reproduced in Fig I. Although no critical study of the apparently obvious method of calculation has been published, one cannot proceed very far in the computation without encountering some rather fundamental questions not yet answered in the literature. This paper is not written under the pretense that the whole transition-zone problem has been fully and satisfactorily solved. Its purpose, rather, is to discuss suggestions for its treatment, much of it admittedly hypothetical, and emphasize the nature of the uncertainties arising therein; for the literature, as now available, gives little indication that there are any problems still outstanding. The Transition-zone Equation The basic equation, which presumably gives directly the fluid distribution without recourse to any further consideration, is: Ap = (r1 - r2)gh [1] where r1, y2 are the densities of the two contiguous fluids, h is the height above the "capillary-free" zone of complete saturation with fluid I, g the acceleration of gravity, and Ap is the capillary pressure across the average interface at the height

Jan 1, 1949

By William E. Hubbard

The production of the Texas Panhandle1 up to Jan. 1, 1932, was slightly under 179,000,000 bbl., 90 per cent of which came from Hutchin-son and Gray counties. About 21,500,000 bbl. were produced during 1931. This was about 35 per cent less than the 1930 production and the smallest annual production since the first boom started seven years ago. The present daily production is slightly under 55,000 bbl., which is the production permitted under statewide curtailment. The assumed potential for the purpose of curtailment is 108,708 bbl. and the actual capacity of the wells is probably in the neighborhood of 75,000 barrels. The total initial production of the oil wells completed in 1931 was 40,714 bbl. from 117 wells or 347 bbl. per well as compared to a 511-bbl. average from the 304 oil wells drilled during the preceding year. Gray County led with 71 completions and a total initial production of 29,209 barrels. Completions Two hundred wells were completed in the Panhandle in 1931, as against 526 in 1930. Of the year's completions, 117 were oil wells, 77 produced gas, and but six were dry holes. Of the 3197 wells drilled in the Panhandle to date, 2944 have produced oil, gas, or both, making the ratio of dry holes to producers about 1:11.7. Ignoring the 64 dry holes drilled in nonproductive counties the ratio becomes 190:2944 or 1:15.5, which is somewhat more favorable than that obtained at the end of 1930. Of the oil wells completed 374 have been plugged. Although it is but five years since the peak of drilling operations more than one-fifth of the oil wells in Hutchinson County have been plugged. The percentage of total wells plugged to total completed oil wells, by counties,

Jan 1, 1932

By Charles M. Brinckerhoff

The Potrerillos mine of the Andes Copper Mining Co., a subsidiary of Anaconda Copper Mining Co., is 100 miles east of the coast town of Chanaral, in the Province of Atacama, Chile. In December 1926, the plant was placed in operation and has operated continuously ever since. Block caving is the only mining method used, as it is especially suited to the grade of ore, the position and shape of the ore bodies, and the character of the ground. At the present time there are three haulage levels, which handle oxide and sulphide ores, and production from them averages 31,000 short tons daily. The purpose of this paper is to describe the layout, equipment and systems used on the gathering or main haulage levels. Haulage Layout Because of the shapes of the ore bodies, their distances from the dumping pockets

Jan 1, 1946

By J. P. Witherow

MR. BIRKINBINE'S description of the bad working and sudden chilling of the Warwick Furnace last summer, seems to me quite phenomenal in blast-furnace practice. During my connection with the management of blast furnaces for many years, in the anthracite, coke, and raw-bituminous coal districts, such a case has never come under my notice. It seems to me that the scaffold in the zone of fusion could not have established itself (so that the whole power of the engines, with a blast pressure ranging from 12 to 18 pounds per square inch, could not penetrate), unless the furnace was previously badly scaffolded and bridged in some of its upper sections, from 15 to 30 feet above the hearth level, either in the zone of chemical action or the beginning of the zone of fusion. Such a "barrier to the upward gaseous currents would cause a suspension of combustion which may have superinducedd the scaffold that is assumed to have existed in the zone of fusion. It is Difficult to conceive' that an agglomerated mass almost across the section of the lower bosh should have formed all at once, if the furnace was free and porous for the reaction of the gaseous currents above. Therefore, I think, the Warwick furnace was by no means in as free, open, and fine internal condition at the time the trouble commenced as the description of its regular working would lead us to suppose. I do not question the accuracy of the statements relative to the output of iron, etc. I merely claim that the phenomena., as described, could not have been almost instantaneously developed, unless there had been an incipient seaffold and lodgment above the zone of fusion. I would state my hypothesis to be that the stock lodged or collected in some of its upper sections during the process of blowing-in, on which, as a basis, more or less accumulations may .have lodged, and thus, indirectly, caused the formation of the suc- * This paper was not presented to the Institute in its present form, but is based on remarks, in discussion, by the author on Mr. Birkinbine's paper on, a Short Blast at the Warwick Furnace, and Mr. Witherbee's paper on Two Scaffolds at the Cedar Point Furnace.

Jan 1, 1881

By J. A. Elias, R. H. Heyer, J. H. Smith

Plastic anisotropy determined by the ratio of width strain to thickness strain in tensile specimens of low-carbon steels is strongly related to crystallographic preferred orientation. Using(222) Pole figures, a method was developed which permits rapid Predictions of plastic anisotropy for any crystallographic texture or orientation. The method is applied to low-carbon steel sheets in which four different crystallographic orientations were produced by variations in cold rolling and annealing treatments. AnISOTROPIC behavior of metal sheets during plastic deformation has long been evident. A familiar example is earing in cup type draws. During tension testing of sheet specimens, anisotropy results in a difference in width strain as compared with thickness strain. Carpenter and Elam1 observed this phenomenon in single crystals of aluminum for both sheet and rod samples. Lankford, Snyder, and Bauscher2 made tension tests on sheet samples of aluminum-killed low-carbon steel to determine the ratio of the width-to-thickness strains, and showed that this ratio was related to drawing performance. Burns and Heyer3 calculated theoretical ratios of width strain to thickness strain for two specific orientations of the bee system, using <111> as the operative slip direction. These calculated values were in fairly good agreement with the ratios determined by tension tests of low-carbon steel sheets in which these preferred orientations existed. The high degree of plastic anisotropy of silicon steel sheets could also be predicted from their crystallographic structure by these calculations. The present study has been made to show that the anisotropy observed in plastic tensile straining is strongly orientation dependent and can be adequately predicted for many orientations and textures. PLASTIC STRAIN RATIO R In the region of uniform elongation of a tension test specimen the plastic deformation may proceed at different rates in the width and thickness directions. Such anisotropy has been described in the past by the plastic strain ratioR:

Jan 1, 1962

By William L. Saunders

MANY members of the Institute, who participated in the visit made, during the Bethlehem meeting of February, 1906, to the shops of the Ingersoll-Rand Company, at Phillipsburg, N. J., inspected with interest the new Electric-Air drill, which the company had set up for the purpose of showing it in actual operation to American. mining engineers. At the request of the Secretary of the Institute, I promised at that time to prepare a paper for our Transactions, describing the construction and advantages of the machine. But such a paper would then necessarily have contained much that was only expected or claimed by the designers and manufacturers of the drill, and not yet incontrovertibly proved by varied and long-continued practice. However moderate such statements might have been, they would have given inevitably to the paper, to some extent at least, the air of a prospectus, rather than of a technical contribution. I therefore decided, with the Secretary&apos;s approval, to postpone the writing of the promised paper until it could set forth the results of adequate actual practice, as well as the latest details of construction, etc., based upon practical experience. That period has now arrived. The Electric-Air drill has been exhaustively tested in the field, under varied and arduous conditions and upon the hardest rocks. It is now fairly in the field; its merits and performances are matters of unimpeachable record, and its place among established competitors can be definitely determined. As a representative of the Ingersoll-Rand Co., as well as a member of the Institute, I may be permitted to add that my company, being largely interested in the manufacture of air-

Jan 9, 1907

By F. H. Deily, L. W. Ledgerwood, J. E. Eckel

A new method for drilling the earth&apos;s formations has undergone extensive laboratory and shallow earth drilling experimentation. This method, pellet impact drilling, uses the energy of a large mass of high velocity steel spheres to break and crush the rock. Pellets are confined to a region close to the hole bottom. Motive fluid for transporting and recycling the pellets is supplied by a modified jet pump. The pellet drilling method has inherent advantages over conventional rotary drilling. First, only a nominal amount of weight need be applied to the hole bottom. Second, only a very small amount of torque is required for bit rotation. Third, means are available for continual replacement of the cutter medium. The experimental laboratory work and analytical procedures necessary for the design of a pellet drill bit are described. In the laboratory program approximately half the effort was devoted to the development of a better understanding of the physical process, and half to the empirical testing of new bit configurations. Factors such as pellet size and velocity, jet pump characteristics and modifications, and power distribution are discussed. The design and construction of a pellet impact bit for drilling a 9 in. hole with 1 1/4 in. steel pellets are described. Drilling performance in representative rocks, hydraulic operating characteristics, and metallurgical problems are discussed. INTRODUCTION This paper discusses an attempt to reduce drilling costs through the development of a drilling method basically different from rotary drilling. Publications on drilling research indicate that the major effort on the part of manufacturers and operators has been confined to research in rotary, or rotary-percussion drilling. This applied drilling research has produced significant gains in drilling rates and bit life, but thus far it has failed to achieve any major decrease in general drilling costs. From recent statistics released by Drilling Contractors, it can be shown that the total cost of drilling an "average" well in 1953 was about 2 1/4 times the corresponding cost in 1935. Analysis of the costs will show that they are not due to inefficient field operations; they are due instead to both an inflated economy and greater "average" well depths. Diligent work by the industry has reduced the backlog of potential economic improvements in rotary drilling to a group of rather marginal prospects. Increasing depths and poorer quality reservoirs at these depths continue to make the drilling cost problem more acute. Hence, the aim of the work reported here was to develop a new drilling method not limited by the inherent characteristics of rotary drilling and thus capable of attaining further significant reductions in drilling costs. The effort devoted to research on this proposed new drilling method was of considerable magnitude and represented .in excess of 37 man-years of research. The affiliates of Standard Oil Co. (N. I.) sponsored this development program which was conducted by the Drilling Methods Section of the Carter Research Laboratory in Tulsa, Okla. The purpose of this paper is to

Jan 1, 1957

By C. L. Sollenberger, Will Mitchell, Ford F. Miskell

Heat treatment of ore prior to comminution reduces power requirements for grinding, reduces grinding media wear, and improves recovery of iron values from a typical Minnesota magnetic taconite. Test data demonstrating this, as well as an analysis of the economics of commercial application of the technique, are presented. THE taconites in general are hard, tough ores, difficult to grind. Liberation of iron mineral constituents usually is accomplished by grinding the ore through at least 100 mesh, and often it has been found necessary to grind substantially through 325 mesh to achieve satisfactory recovery and grade in the concentration process. Because of the fineness of grind required and the enormous tonnages of material contemplated for treatment in the future, costs resulting from grinding media wear and power consumption, together with capital investment required for comminution, approach astronomical figures. Economy in any one of these elements per ton of material ground could very well reflect a considerable saving to the ferrous industry in yearly costs. With this in mind, the Research Laboratories of Allis-Chalmers Manufacturing Co. have launched a program to discover means of effecting this economy. The initial phase of the work as described here deals with a heat treatment of crushed raw ore, followed by thermal shock in cooling, for the preparation of rod mill feed. Several investigators1-" ave noted an improvement in the grindabilities of ores treated in this manner. One investigator2 subjected low grade iron ores to heat treatment in an electric furnace. Basing his conclusions on screen analyses of crushed products, he observed that treated ore was more easily crushed than the untreated. He reported that observation of the treated and untreated ore through a microscope revealed cracks following the grain boundaries in treated ore, whereas no cracks were present in untreated ore. However, few if any have quantified the improvement in terms of total hp hours saved, reduction of wear of grinding media, or reduction of capital costs of grinding equipment involved. By means of Bond rod mill and ball mill grindabilitiesh nd by comparative wear tests, the conditions maintained during this investigation have been definitely evaluated. Heat treatment experiments have been made on a batch scale in a muffle furnace, followed by continuous scale experiments in a rotary kiln under various conditions of temperature, atmosphere, retention time, and quenching to determine the combination that would give the greatest improvement in the grindability of a taconite without affecting adversely the magnetic susceptibility of the magnetite. From these data, relative costs have been calculated for grinding both untreated and heat- treated ore on a basis of plant capacity of 120 tons per hour. Heat requirements for a rotary kiln, as well as the kiln capacity required for the treatment, have been estimated. For these tests 50 tons of ore were obtained from the Aurora mine of the Erie Mining Co., Hibbing, Minn. The ore was reported7 to have been selected from the magnetic portion of the lower chert horizons. An average chemical analysis of&apos; this portion is shown in Table I and an approximate mineralogi-cal analysis is shown in Table 11. No attempt was made to differentiate between the various silicates because the compositions vary widely on the different horizons and depend on the degree of oxidation. Minnesotite, however, is the predominant silicate. The siderite grains were dispersed throughout the ore but were essentially associated with the rock-forming minerals. In a series of preliminary tests in which batches of —6 mesh ore were heat-treated in a muffle fur-

Jan 1, 1953

By Will Mitchell, Ford F. Miskell, C. L. Sollenberger

Heat treatment of ore prior to comminution reduces power requirements for grinding, reduces grinding media wear, and improves recovery of iron values from a typical Minnesota magnetic taconite. Test data demonstrating this, as well as an analysis of the economics of commercial application of the technique, are presented. THE taconites in general are hard, tough ores, difficult to grind. Liberation of iron mineral constituents usually is accomplished by grinding the ore through at least 100 mesh, and often it has been found necessary to grind substantially through 325 mesh to achieve satisfactory recovery and grade in the concentration process. Because of the fineness of grind required and the enormous tonnages of material contemplated for treatment in the future, costs resulting from grinding media wear and power consumption, together with capital investment required for comminution, approach astronomical figures. Economy in any one of these elements per ton of material ground could very well reflect a considerable saving to the ferrous industry in yearly costs. With this in mind, the Research Laboratories of Allis-Chalmers Manufacturing Co. have launched a program to discover means of effecting this economy. The initial phase of the work as described here deals with a heat treatment of crushed raw ore, followed by thermal shock in cooling, for the preparation of rod mill feed. Several investigators1-" ave noted an improvement in the grindabilities of ores treated in this manner. One investigator2 subjected low grade iron ores to heat treatment in an electric furnace. Basing his conclusions on screen analyses of crushed products, he observed that treated ore was more easily crushed than the untreated. He reported that observation of the treated and untreated ore through a microscope revealed cracks following the grain boundaries in treated ore, whereas no cracks were present in untreated ore. However, few if any have quantified the improvement in terms of total hp hours saved, reduction of wear of grinding media, or reduction of capital costs of grinding equipment involved. By means of Bond rod mill and ball mill grindabilitiesh nd by comparative wear tests, the conditions maintained during this investigation have been definitely evaluated. Heat treatment experiments have been made on a batch scale in a muffle furnace, followed by continuous scale experiments in a rotary kiln under various conditions of temperature, atmosphere, retention time, and quenching to determine the combination that would give the greatest improvement in the grindability of a taconite without affecting adversely the magnetic susceptibility of the magnetite. From these data, relative costs have been calculated for grinding both untreated and heat- treated ore on a basis of plant capacity of 120 tons per hour. Heat requirements for a rotary kiln, as well as the kiln capacity required for the treatment, have been estimated. For these tests 50 tons of ore were obtained from the Aurora mine of the Erie Mining Co., Hibbing, Minn. The ore was reported7 to have been selected from the magnetic portion of the lower chert horizons. An average chemical analysis of&apos; this portion is shown in Table I and an approximate mineralogi-cal analysis is shown in Table 11. No attempt was made to differentiate between the various silicates because the compositions vary widely on the different horizons and depend on the degree of oxidation. Minnesotite, however, is the predominant silicate. The siderite grains were dispersed throughout the ore but were essentially associated with the rock-forming minerals. In a series of preliminary tests in which batches of —6 mesh ore were heat-treated in a muffle fur-

Jan 1, 1953

By K. Leutwyler

The authors present an interesting review of various applications of rather well known theories. Their rearrangement of the original working equations is strictly computer oriented and serves well to that effect; however, the new appearance will be confusing to the slide rule-wielding members of the profession. In reviewing discrepancies existing between calculations made by Baker Oil Tools, Inc. field engineering staff members and computer output submitted based on the authors&apos; program, the following error in concept was discovered in Eq. 4. The authors quote the length change due to helical buckling in the following form We appreciate Kurt Leutwyler&apos;s awareness of Archimedes&apos; principle, and concur that the final term in the denominator of Eq. 4 results in a small error. Examples checked revealed less than I ft error, and corrective expressions for the four possibilities of displacement follow. The portion of the denominator within extra large brackets represents the original term W,, = weight of outside fluid displaced per unit length. The authors interpreted the expression "displaced" in general oilfield terminology as a fluid displacement, such as "mud displaced with water, etc." A review of the theory forming the basis for these helical buckling calculations discloses that this displacement is meant to be interpreted in the Archimedean sense, i.e., fluid displaced by the solid body. here the tubing and the seal nipple. Lubinski* illustrated the point by summing moments due to mechanical and hydraulic forces acting on a free body immersed in fluid. This moment summation, always in the Archi,medean sense, yields effects of the real forces, including W,, and the fictitious force on the bending mechanism. I would be interested to hear the authors&apos; comments regarding this theoretical point, which nevertheless is not mute since its lack of recognition seems to result in erroneous calculations. We must not remain mute to Leutwyler&apos;s suggestion that these equations, although computer oriented, are confusing to the slide rule engineers. Such input information as density in pounds per gallon, pipe diameters in inches, pumping rate in barrels per minute and pipe length in feet is not confusing to most of us. Yet there may be some rugged individuals in field positions who carry tables of conversion constants and have committed to memory such items as coefficients of thermal expansion and Poisson&apos;s ratio; however, even this type of individual would welcome a simplified equation occasionally. M

By J. Chipman, H. Towers, M. Paris

A simple radioactive tracer technique is used to measure the diffusion coefficient of calcium ion in molten slags. In a slag of 40 pct Ca0-40 pct Si0,-20 pct Al203, Dc " at 1450°C is 1.3x10-6 cm&apos; sec-&apos;. THE application of the principles of thermodynamics to steel and iron making problems has proved so fruitful that the kinetic approach has tended to be neglected. It seems probable that in some reactions the rate-determining step is the dif-fusivity of the reactants or of the products. But knowledge of the diffusion coefficients of the constituents of liquid slag and metal is singularly lacking. The present work was undertaken as a first step toward supplying such data for slags. Furthermore, any additional information on the physical properties of liquid slags might be expected to help in elucidating their structure. It is essentially a preliminary investigation, the course of which was determined more by the necessity of establishing a method than by the immediate intrinsic interest of the results. For example, the selection of calcium ion to be studied was dictated by the suitability of the isotope Ca45 in that it is a simple emitter with a long half-life. Of the other ions commonly encountered in slags, the isotopes of iron and manganese have relatively complex radiations as well as the normal disadvantage of requiring control of the oxygen potential of the atmosphere; Mg27 and Al29 have half-lives measured only in minutes; Si3&apos; has a simple decay process but its half-life of 2.8 hr is too short for preliminary studies; the only useful oxygen isotope is the stable O18; and there remain only sulphur and phosphorus both of which have suitable isotopes but were rejected as being of less fundamental interest than calcium. Similarly a lime-alumina- silica slag was used in preference to calcium silicate primarily because of its low melting point and its capacity to form a glass on fairly rapid cooling. Literature Review Very few studies of diffusion in liquid silicate systems have been reported. In order to determine the origin of diopside inclusions in felspathic rocks, Bowen1 investigated the diffusion between diopside and various mixtures of albite and anorthite. Platinum crucibles were used with diopside, the heavier of the two liquids, forming the lower half of the cell and diffusion taking place against gravity. Change in concentration along the diffusion path was found by measuring the refractive index of the quenched glass. Nearly thirty years later McCallum and Barrett2 used essentially the same method to determine the diffusion coefficient of lime in lime-alumina-silica slags. In this case the interest was to find the rate-determining step in the process of slag attack on refractory materials. In an investigation of the kinetics of the sulphur reaction, Derge, Philbrook, and Goldman8 determined the diffusion coefficient of sulphur in a typical blast furnace slag by the simple procedure of melting a slag containing 2 pct S over an identical slag sulphur-free. They make no claim to a high degree of accuracy but suggest that D, is of the order of 10-6 cm2 sec-l. Other high temperature liquid diffusion studies have been concerned with metals. Holbrook, Furnas, and Joseph4 determined the diffusion coefficients of silicon, phosphorus, sulphur, manganese, and carbon in liquid iron by immersing a small carbon crucible containing pure iron-carbon alloy in a large vessel containing iron with a high concentration of the particular element. Their results were confirmed by Paschke and Hauttmann5 using a similar method. Diffusion coefficients in silicates in the glassy state have been studied by Johnson, Bristow, and Blau6 Both Na24 and Ca45 were used as tracers but only the

Jan 1, 1954

By T. E. Davidson, A. P. Lee

It is known from the early work of Bridgman that the two lowest-pressure transitions (I-II and II-III) are accompanied by substantial and abrupt changes in resistivity and Volume. However, unlike the temperature -induced allotropic transformations observed in such elements as lithium, cobalt, tin, and so forth, there is little actually known about many of the characteristics of the pressure-in&ced transitions. This current work involves an examination of the structural and transformation characteristics of the bismuth I-II and II-III transitions under hydrostatic pressures. The relationship of initial structure to the transformation pressure, rate, resistivity change, and resultant structure is discussed. It is shown that the transition pressure and transformation rate are independent of the presence of grain boundaries and associated anisotropy-induced deformation. An observed hysteresis in both the I-II and II-III transitions is shown. BISMUTH is one of the most interesting of the elements exhibiting pressure-induced polymorphs since it undergoes several allotropic transformations at pressures below 90,000 atm. It is known from the early work of bridman1,2 that the two lowest-pressure transitions (1-11 and 11-111) are accompanied by substantial and abrupt changes in resistance and volume. However, unlike the temperature-induced allotropic transformations observed in such elements as lithium, cobalt, tin, and so forth, there is little actually known about many of the characteristics of these pressure-induced transitions. It is the purpose of this work to examine some of the structural and transformation characteristics of the bismuth 1-11 and 11-111 transitions under hydrostatic pressures. Another interesting characteristic of bismuth is that, in its polycrystalline form, hydrostatic pressures of sufficient magnitude will induce severe progressive plastic deformation in the region of the grain boundaries.3 This deformation, which has also been observed in several other metals, is attributed to the high degree of anisotropy in the linear compressibility of bismuth, resulting in shear stresses in the grain boundaries when it is exposed to hydrostatic pressure. Most thermally induced allotropic transformations in metals, whether of the diffusionless ather-ma1 (martensitic) or isothermal nucleation and growth types, are dependent upon structure and prior history,4 viz., grain boundaries, deformation, and so forth. One logically wonders then whether the transformation characteristics of the pressure-induced polymorphs in bismuth might also depend upon initial structure, particularly with respect to the presence of grain boundaries and associated plastic deformation. In this investigation, the role of grain boundaries and plastic deformation on the characteristics of the bismuth I-II and 11-111 transitions will be established. The rather unique residual microstruc-tural changes associated with these transitions will be presented and discussed. The occurrence of a measurable hysteresis in both the I-II and 11-111 transitions will be demonstrated. The type of transformation mechanism based on the observed transformation rate will be discussed. EXPERIMENTAL PROCEDURE A) Apparatus. The hydrostatic pressure system utilized in this investigation is similar to that previously reported by Bridgman&apos; and Birch and Robertson,5 and has been previously described.3 For the purpose of this work, the pressure medium utilized was a 1:l mixture of pentane and isopentane. Pressure measurement was by means of a manganin coil in conjunction with a Foxboro Recorder. The manganin coil was mounted in the bottom closure and inserted inside the pressure cavity. Based on calibration against a controlled clearance piston gage at approximately 10,000 atm, the estimated error in the pressure measurement was +2 pct. Assuming the nonlinearity in the pressure coefficient of resistivity between 10,000 and 28,000 atm to be not greater than 1 pct, then the estimated error in the range of the I-II and 11-111 transitions was +3 pct. B) specimen Material and Preparation. The bismuth utilized throughout this investigation was of

Jan 1, 1964

By T. L. Johnston

MUCH has been said and written about deep mine shafts and deep drill holes as man in his search for mineral wealth digs deeper into the earth&apos;s crust. Each year some new extra depth is heralded as a record, but with unlimited possibilities of going still deeper. In contrast to "digging deep," "mining high" is limited by the height of the mountains (Mt. Everest being the maximum with its 29,000-ft. elevation) and also by the extent of human endurance. An ex- ample of what might be called near- stratosphere mining in what is probably the highest mine worked by compressed air in the world is seen in a recent project in the Andes mountains of southwestern Bolivia.

Jan 1, 1939

By Charles Camsell

MORE than one-third of all Canada is embraced in the federal domain known as the Northwest Territories. Its most northern point, Cape Columbia, on Ellesmere Island, is only 500 mi. from the Pole. It includes parts of the main physiographic divisions of the North American continent. In the West there is a strip of 30.000 sq. mi. lying in the Cordilleran region, where peaks in the Mackenzie Mountains rise as high as 8500 ft. East of this strip and extending roughly to a line through Great Bear and Great Slave lakes to the Arctic coast is a section of the interior plains. This section, known as the Mackenzie Lowlands, contains the great artery, the most striking feature of the Northwest Territories-the Mackenzie and Slave river waterway impressive in its width, almost two miles in places, and in it&apos;s navigability for 1357 miles without obstruction to the sea. Adjoining the Mackenzie Lowlands on the East is the greater portion of the mainland of the Territories, which, as well as a large share of the island area, is in the Canadian Shield.

Jan 1, 1937

By William P. Blake

This camp is just now startled by the alarming suggestion that unless there shall speedily be an appreciation in the value of silver, and a decrease in the cost of salt, it will be prudent business policy to close the Alice mines and mills until the conditions of production are more favorable. Such an event would be a great blow to the prosperity of Butte. It would throw some hundreds of men out of employment, and it might lead to the adoption of the same policy by other companies, which, like the Alice, have not been able to pay dividends to their shareholders for a long time. The question arises, and becomes emphatic: If, under the present adverse conditions, the mines and mills cannot be made to pay a proper profit, why should they continue to be worked ? The owners mentally ask: Shall we go on exhausting our mines, pouring out a stream of silver for the maintenance of the community, and the support of the rail ways, or shall we husband our reserves, withdraw the miners from our slopes, and wait for more favorable conditions ? This is the impending question, and all concerned dread to meet and answer it. Let us briefly review the situation and forecast, if possible, what the solution of&apos; the problem will be. It must be understood that the discussion does not include, or refer to, the immense copper-producing interests of the camp, which may or may not be upon a very much more satisfactory basis. It will be confined chiefly to the operations of the Alice company, sta tistics of which are at hand, without involving the other silver com panies in the conclusions beyond those inevitable from well-known facts, patent to all. There are at present in Butte and in its vicinity in the principal mills an aggregate of 290 stamps dropping upon silver-ores: Alice,...........80 stamps. Moulton,. .........40 " Lexington,...50 " Silver Bow,.........30 " Blue Bird,..........90 " The Alice mills at present, with their 80 stamps, devour, in round numbers, from 100 to 120 tons a day. The actual amount

Jan 1, 1888

By A. B. Johnson, J. S. Browning

The USBM has developed new and improved physical beneficiation techniques for economically recovering potash minerals from high-clay and low-grade ore from the Permian Basin of New Mexico. With the depletion of the high-grade ores a need for changes in industry&apos;s standard methods of recovery is a must. Technology may be improved in the beneficiation of the ore prior to mineral flotation and in brine clarification from the desliming phase to effect a reduction of losses of fine potash and brine in the disposal of the clay slimes. This report summarizes the results of these tests and demonstrates the feasibility of producing products that meet the requirements of the agriculture market, namely, 95% KCl equivalent to 60% K2O with recoveries ranging between 80 and 90%.

Jan 1, 1973