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By Joseph Moses Botbol

This study was designed to demonstrate the viability of using high-frequency radio transmission as a means of communications between a remote field camp and a time- sharing computer system. A field camp near Johnstown, Pa., was linked by high- frequency radio to a base station 160 miles to the southeast in Vienna, Va. The base station was in turn linked by telephone to a time-sharing computer system near Los Angeles, Cal. Error-free data transmission utilized highly stable receivers and transmitters, forward error correction, and dual-frequency diversity. Three geologic applications programs resident in the Los Angeles computer were executed from a graphics cathode ray tube terminal in the field. Bulk data equivalent in volume to 4 days of typical spectrographic analytical work generated by one spectrograph and one spectrophotometer were transmitted from the field to the base station. All programs, were executed successfully, and all data were transmitted error free.

Jan 1, 1976

By C. M. Weld

The southeastern coast of China, from Ning-Po to .Macao, represents an element in the continental mass of Asia which has at practically all times in the remote past exhibited a tendency to rise rather than to subside.' This strip of land, 1,000 or more miles long by perhaps 150 miles wide at its widest part, has in fact stood above sea level since at least early Cambrian times, while the great basins to the north and west were receiving their massive accumulations of Sinian (Cambro-Ordovician), Carboniferous, and later deposits. We find, .therefore, a coastal fringe of metamorphic and igneous rocks bordering the huge expanses of sedimentary rocks which occupy the interior. Hong-Kong is situated toward the southwestern extremity of this fringe. Hong-Kong is an island of approximately 30 sq. miles, on the north shore of which is situated the city of Victoria, with its 325,000 inhabitants. This island was ceded to Great Britain in 1842. In 1560 the peninsula of Kowloon (about 5 sq. miles), being that part of the mainland lying directly across from the city of Victoria, was added to Hong Kong. Thirty-eight years later, in 1898, a stretch of territory, including the mainland behind Kowloon and. numerous adjacent islands, was leased to Great Britain for 99 years. This last addition is known as the "New Territory of Hong-Kong" and comprises 376 sq. miles in area. A map of Hong-Kong, Kowloon, and the "New Territory" is shown in Fig. 1. My studies of this total area of over 400 sq. miles were devoted primarily to an investigation of the mineral resources. Systematic mapping of the immensely complex exposures of rocks was not possible in the time at my disposal. However, observations in, this. direction warrant a few generalizations.

Jan 2, 1914

By Robert R. Turner

This paper discusses wet and dry primary autogenous and semi-autogenous grinding, including a description of the equipment and its mode of operation, testing and the scaling-up of test data. Lists of selected literature references are included.

Jan 1, 1982

By Donald W. Scott, Adam L. Wesner

THE inevitable depletion of Mesabi direct-ship- ping iron ores, hastened by recent wars, has increased the importance of developing methods to concentrate iron-formation materials. Many mining companies, independent research organizations, chemical companies, and equipment manufacturers are devoting attention to this important work. It is only natural that magnetic iron-formation materials have received major emphasis, since magnetic recovery methods apply and reserves of Mesabi magnetic taconites are large. However, the non- magnetic* iron-formation materials are likewise believed to represent a large reserve and their study has not been neglected.

Jan 6, 1954

By John W. Rushton

What role does maintenance play in the design of a new mineral processing facility? Consider the fact that most new plants never reach design capacity the first year-or the second, third, or fourth years. The fact is, according to data collected from several plants which have started up in the last ten years, mill throughput and equipment availability doesn't peak, on the average, until the fifth year.

Jan 3, 1978

By L. C. De Jong, J. F. Shirley, M. L. Campbell

At the Southern Peru Copper operation in Toque-pala, Peru, a new process flowsheet for the recovery of byproduct molybdenite has proved successful in dealing with complex and highly variable ores. This paper describes the process and the functions of each of the chemicals used. The Toquepala concentrator of the Southern Peru Copper Corp., located approximately 720 miles southeast of Lima near the Chilean border, processes a daily 36,500 tons of ore containing between 0.50 and 3.00% copper. The molybdenite content in the ore also varies greatly ranging from essentially nothing to as high as 0.15%. The 1966 yearly averages were approximately 1.20% copper and 0.03% molybdenite. The Toquepala porphyry deposit is a mushroom-shaped ore body consisting of a flat-lying enriched zone of predominant chalcocite with a stem-like extension of hypogene chalcopyrite ore in depth within and around a large breccia pipe.1 The underlying chalcopyrite ore has not been reached; however, due to the presence of a major post orebody fault, predominantly chalcopyrite ore is present in the north side of the pit. Most of the molybdenite occurs either as small, fine granular, pulverulent masses in vugs or empty voids of breccia, or as thin foliated masses and narrow thread-like filling in rock joints and fractures. The normal occurrence of quartz gangue with the molybdenite gives some basis for correlating the molybdenite mineralization to some later periods of silicification. On April 18, 1962, the molybdenite recovery plant at Toquepala went on stream, approximately 27 months after the copper concentrator had been in production. The plant was designed and built by Southern Peru Copper Corp.'s engineering and mechanical departments. The basic method chosen for separating the molybdenite from the copper concentrate was the sodium hypochlorite-sodium ferrocyan-ide process. The selection of this process was based on the results of an extensive testing program performed by the Colorado School of Mines Research Foundation, Inc. and the economic conditions of the area. The originally designed process could never be fully implemented due to a lack of sodium hypo-chlorite and has had to be continually modified to satisfy the requirements of the kaleidoscope of ores from the mine. The three basic problems that plague the operation of any molybdenite recovery plant are all present at Toquepala in large measure. Both the quantity of plant feed and the quantity of molybdenite contained in the plant feed are continuously changing. Even more detrimental to an efficient operation is the fact that the copper mineralization in the feed frequently changes once in every 24 hours and occasionally once a shift. From the point of view of the molyb-

Jan 1, 1968

By Thomas Egleston

The uncertainty of finding the exact equivalents fortechnical expressions in different languages has led me to think that a glossary of furnace-terms would be useful to members of the profession. I was led, some years ago, to prepare a small one, which has been found so very useful, that I have arranged one for presentation to the Institute, for four different 'types of furnaces, in the hope that it may prove of use to those who are in the habit of consulting foreign technical journals, I was further induced to make the attempt in the hope that it might tend to make the terminology less complicated than it now is, and also to make it more uniform over larger districts. The idea of referring to a drawing which expresses exactly what is meant, resulted from the necessity of presenting such subjects to students, and will, it is hoped, prove much more useful than the mere dictionary arrangement in alphabetical order. The drawing of the blast-furnace was prepared for me by Mr. J. P. Witherow, of Pitsburgh ; the drawing of the open-hearth furnace by Mr. S. T. Wellman, of Cleveland, and the reverberatory furnace by Mr. John Fritz, of Bethlehem. The bloomary-furnace is taken from my own paper* on Bloomaries, but, in order to have a complete furnace, I have introduced into the drawing of those used at Saranac the guard-plate used at Ironville. The interest which has been taken in the preparation of this paper by those gentlemen who have contributed the drawings, has been supplemented by gentlemen in Europe who have taken the trouble to read the proof. In France it has been read by Mr. Lodin, of the School of Mines, and by Mr. Chaper, of Paris, and in Germany by Dr. Wedding, of Berlin, and Mr. Luhrman, of Osnabruck. The preparation of the paper has been much more difficult than was anticipated, and its value has been very much enhanced by Dr. Raymond's kind assistance and cooperation; and to him, as well as to all the other gentlemen, Iam very much indebted. It was at first proposed to add to the paper the names of all the tools used in these various furnaces. It was found, however, that this would make such

Jan 1, 1888

By D. A. Dahlstrom

THE necessity for slime elimination from valuable mineral and coal products has become increasingly significant within the past 5 years.1,2 Most of the mechanized mining and present beneficiation methods have resulted in larger tonnages of extreme fines, silts, and clay, commonly called slimes, processed by the preparation plant. Economics in turn have forced the plant operator constantly to lower the bottom size of effective beneficiation, necessitating an almost complete recovery of valuable solids regardless of particle size. When these important factors are considered, the need for an efficient slime removal method for fine solids becomes self-evident. Ordinarily slimes have been classified as ranging from 75 microns, or 200 mesh, down to colloidal dimensions of less than one micron. At the same time there is general agreement that the most troublesome slimes are primarily clays, silts and extreme fines, so that the actual top size may be placed at approximately 30 to 40 microns. This immediately restricts any desliming operation to classification, as screening or other methods would be both uneconomical and grossly inefficient at such dimensions. The liquid-solid cyclone has been recognized as one of the most efficient fine size classifiers available to the mining industry. Applications of cyclones to thickening, high efficiency solid recovery, degritting,

Jan 1, 1952

By Guy W. Jordan, David P. Hale

High-iRon cements have a number of advantages over cements carrying little or no iron. The presence of iron in Portland cement aids in the manufacture of the cement and also imparts certain advantageous physical properties to the finished product. In manufacture, the presence of iron lowers the fuel consumption, increases the ease of proper"burning, and lessens the destructive action of the charge on the kiln refractories. In the finished cement the presence of iron reduces the expansion and contraction, adds strength, adds increased resistance to"freezing and thawing, and increases the resistance of the cement to sea "or sulphate waters. [" During the past few years the construction of numerous dams through- "out the Southeast by the Tennessee Valley Authority has stimulated the "production of high-iron cements. At present a great number of specifica- "tions call for an iron cement, and the industry is supplying this demand "with a Portland cement carrying approximately 5 per cent iron oxide. "Several manufacturers are now making practically all of their cement "of this type and a number of others manufacture it as a special cement "over short periods to meet demands from the Tennessee Valley Authority "and other buyers. " The recent increase in the use of iron in Portland cement has created "a market for iron products that previously was nonexistent. The chief "sources of supply for the cement manufacturers at present are iron sand, "iron sinter and slag, and ocher. The Copperhill mining district, Ten- "nessee, supplies both iron sinter and slag for use in cement. The Carters- "ville district supplies iron sand, ocher, and some iron resulting from the "magnetic separation of iron from barite. The advantages of these "products vary according to the chemical properties of the raw materials "and the methods of handling used by the different manufacturers. Where "the iron is to be handled by conveying belts and in hopper cars, the iron"sand and sinter and slag are preferable. Where the silica content must "be raised, the iron sand is doubly advantageous because it supplies both

Jan 1, 1942

By David P. Hale, Guy W. Jordan

High-iRon cements have a number of advantages over cements carrying little or no iron. The presence of iron in Portland cement aids in the manufacture of the cement and also imparts certain advantageous physical properties to the finished product. In manufacture, the presence of iron lowers the fuel consumption, increases the ease of proper"burning, and lessens the destructive action of the charge on the kiln refractories. In the finished cement the presence of iron reduces the expansion and contraction, adds strength, adds increased resistance to"freezing and thawing, and increases the resistance of the cement to sea "or sulphate waters. [" During the past few years the construction of numerous dams through- "out the Southeast by the Tennessee Valley Authority has stimulated the "production of high-iron cements. At present a great number of specifica- "tions call for an iron cement, and the industry is supplying this demand "with a Portland cement carrying approximately 5 per cent iron oxide. "Several manufacturers are now making practically all of their cement "of this type and a number of others manufacture it as a special cement "over short periods to meet demands from the Tennessee Valley Authority "and other buyers. " The recent increase in the use of iron in Portland cement has created "a market for iron products that previously was nonexistent. The chief "sources of supply for the cement manufacturers at present are iron sand, "iron sinter and slag, and ocher. The Copperhill mining district, Ten- "nessee, supplies both iron sinter and slag for use in cement. The Carters- "ville district supplies iron sand, ocher, and some iron resulting from the "magnetic separation of iron from barite. The advantages of these "products vary according to the chemical properties of the raw materials "and the methods of handling used by the different manufacturers. Where "the iron is to be handled by conveying belts and in hopper cars, the iron"sand and sinter and slag are preferable. Where the silica content must "be raised, the iron sand is doubly advantageous because it supplies both

Jan 1, 1942

By R. W. D. Clarke, J. C. Folinsbee

INTRODUCTION This paper deals with a procedure for planning the mining of an orebody for which cross-sections, plans, grade of ore, and a geological estimate of the ore reserve have been prepared. The procedure begins with the preliminary selection of a mining method or methods on which an engineering evaluation will be carried out. The engineering evaluation is described in three parts: Conceptual Studies Engineering Studies Detailed Design An overall planning model is presented, plus an expanded model for the Engineering Study Throughout the discussion of the planning procedure, reference is made to three bulk mining methods, including block caving, sublevel caving, and longhole sublevel stoping, including a summary of the main characteristics of each of these mining methods. The planning model is designed for a longhole sublevel stoping method, but with modification, will apply to other methods. PRELIMINARY SELECTION OF A MINING METHOD To experienced mining engineers, identification of the nominal mining method for a given orebody normally involves a large measure of judgement. The geological data is reviewed to determine the configuration of the orebody, including size, shape, dip, grade, and metal distribution. Geotechnical data is considered, including the competence of the ore and host rock, faults, fracture patterns, groundwater, and the potential for in situ stresses. Geographical data, including the natural and societal conditions, are evaluated for their effect upon the mining method, and finally, economic data, basically defined as the value of the ore in the ground, but more specifically, including grade of mineable ore, distribution of ore grade throughout the orebody, and metallurgical recovery, will have a bearing on the nominal method selected. Preliminary evaluation of these factors will result in the elimination of the obviously inappropriate mining methods, leaving some method or methods for further, more detailed study. Since ore does not occur in simple geometric shapes, the method selected for more detailed study will require some variation to the standard. A few key factors will bear heavily on the selection and provide a basis for the most realistic choice. Geological Data The configuration of an orebody defined by the horizontal and vertical dimensions, the dip and strike, and the possibility of repetitive occurrences will have the major influence on the selection of the mining method. For bulk mining methods, the dip of the orebody should be steep, or the orebody must be thick so that gravity can be utilized to deliver fragmented ore to a central gathering area. Geotechnical Data The geotechnical data will be studied in greater detail when the nominal mining method has been selected and the engineering evaluation is undertaken. However, some basic initial information must be available. The structural strength of the ore and host rock, including the effect on it of faulting, fracturing, and insitu stresses, must be known. Data from exploration drilling and examination of drill core will assist in the preliminary assessment of these factors. Highly fractured ground may suggest a caving method of mining for certain orebody configurations, whereas highly competent or strong ore might indicate that for a similar configuration, longhole sublevel stoping will more likely succeed. Data obtained on groundwater from exploration drilling will be considered to determine if it can be controlled, or if it will represent a long term major expense or a hazard for which no control is possible.

Jan 1, 1981

By James P. Kimball

THE object of the present memoir is to put on record some practical experiments by the writer in smelting a silicious native magnetite with no other flux than the silicates of its own gangue: This work was undertaken in the spring of 1878 for Messrs. Naylor & Co., of Boston, to whom I am indebted for the privilege of here communicating its results, these having hitherto only been simply announced.* So far as I am aware these are the first instances of the kind in this country that non-calcareous; or rather non-carbonated, magnetites have successfully been used strictly alone as self-fluxing ores in the blast furnace; that is, without the addition of calcareous flux in the form either of limestone, quicklime, calcareous ore, or basic (calcareous). slag. Previous to the spring of 1878, when the Chateaugay magnetic ore was first brought to my notice, its use had been limited to Catalan forges, after "separation" at the ore bed. The blooms and billets made from it in the several forges of Messrs. Weed & Williams, and of Mr. Williams, were well known in the trade as among the best in the market. The Chateaugay ore beds proving of great magnitude, and the ore exceptionally low in phosphoric acid, it commended itself for blast-furnace purposes to Messrs. Naylor & Co., who employed nee to blow-in the charcoal furnace at Pittsford, Vt., on this ore in the spring of 1878., a previous trial of this ore in the same furnace in the fall of 1877 having proved abortive. This was therefore the first time that Chateaugay ore was successfully smelted in a blast furnace, although since well known as a blast-furnace ore possessing superior and exceptional qualities. The Pittsford furnace, although rebuilt in 1844, and subsequently improved by the former owner, the late J. Prichard, is one of the few furnaces of the old type with open breast (Sumpfofen) still active in this country. Its improvements on furnaces of the period, * Bulletin American Iron and Steel Association, XII, 1878, 132, 156.

Jan 1, 1881

By Jan Law

Problems of oil recovery are attacked from the approaches dictated by the two strikingly dissimilar complexes that comprise an oil reservoir—the fluid complex and the interstitial complex. Knowledge of the fluid complex, due to labors in the fields of fluid mechanics and physical chemistry, has far outdistanced knowledge of the interstitial characteristics of the sand complex. This paper is concerned with the latter and applies the technique of statistics to petrographic facts—namely, porosity and permeability—dealing with what might be called petrometry. Statisticians have long worked within the problem of reconstruction of a universe oi variables by means of samples that comprise a small percentage of the universe from which the samples were drawn. Core-analysis data comply with the requisite of random sampling as stipulated by theoretical statistics. A basic concept of statistics employs t.he following substitution: 1. The results of sampling are arranged as a frequency distribution. 2. The observed frequency distribution is compared with a mathematically precise distribution. 3. If a sufficiently good agreement is found between the two, the precise distribution is substituted in all subsequent operations involving characteristics of the sampled material. This mathematically precise distribution is also known as the normal curve, curve of error, the probability, the Gaussian, and the bell-shaped curve and is describable with but two figures. Further, these two figures, the arithmetic average and the standard deviation, are subject to mathematical manipulation. This paper demonstrates that, in some cases in the Dominguez field of Southern California, if sufficient core-analysis samples are taken over not too great a thickness of sediments, the resultant permeability and porosity assemblages give satisfactory agreement with ilormal curves. It is shown that the indications are strong that oil wells wherein a satisfactory agreement is found are predictable as to productivity. Since the predictions are made by employing the laws of chance that are operative within sedimentation, it follows that the mechanism by which the predictions were made is a basic concept of reservoir mechanics. Therefore, tentative examples are given of the application of normal curves to the solution of problems of primary and secondary recovery. Nature of Permeability Frequency Distributions Core-analysis data are made available as a tabulated depth vs. permeability profile. The nature of the distribution of permeability values within a given strati-graphic interval may be approximated from an array constructed with samples plotted in the order of their appearance with depth (accession number) against their permeability value in millidarcys. A wide variation in the nature of the distribution of K (permeability) values for

Jan 1, 1944

By Jan Law

Problems of oil recovery are attacked from the approaches dictated by the two strikingly dissimilar complexes that comprise an oil reservoir—the fluid complex and the interstitial complex. Knowledge of the fluid complex, due to labors in the fields of fluid mechanics and physical chemistry, has far outdistanced knowledge of the interstitial characteristics of the sand complex. This paper is concerned with the latter and applies the technique of statistics to petrographic facts—namely, porosity and permeability—dealing with what might be called petrometry. Statisticians have long worked within the problem of reconstruction of a universe oi variables by means of samples that comprise a small percentage of the universe from which the samples were drawn. Core-analysis data comply with the requisite of random sampling as stipulated by theoretical statistics. A basic concept of statistics employs t.he following substitution: 1. The results of sampling are arranged as a frequency distribution. 2. The observed frequency distribution is compared with a mathematically precise distribution. 3. If a sufficiently good agreement is found between the two, the precise distribution is substituted in all subsequent operations involving characteristics of the sampled material. This mathematically precise distribution is also known as the normal curve, curve of error, the probability, the Gaussian, and the bell-shaped curve and is describable with but two figures. Further, these two figures, the arithmetic average and the standard deviation, are subject to mathematical manipulation. This paper demonstrates that, in some cases in the Dominguez field of Southern California, if sufficient core-analysis samples are taken over not too great a thickness of sediments, the resultant permeability and porosity assemblages give satisfactory agreement with ilormal curves. It is shown that the indications are strong that oil wells wherein a satisfactory agreement is found are predictable as to productivity. Since the predictions are made by employing the laws of chance that are operative within sedimentation, it follows that the mechanism by which the predictions were made is a basic concept of reservoir mechanics. Therefore, tentative examples are given of the application of normal curves to the solution of problems of primary and secondary recovery. Nature of Permeability Frequency Distributions Core-analysis data are made available as a tabulated depth vs. permeability profile. The nature of the distribution of permeability values within a given strati-graphic interval may be approximated from an array constructed with samples plotted in the order of their appearance with depth (accession number) against their permeability value in millidarcys. A wide variation in the nature of the distribution of K (permeability) values for

Jan 1, 1944

Jan 1, 1917

INTRODUCTION TO SAMPLING THEORY Before specifically discussing mineral sampling and sampling procedures, let us briefly consider broader and more universal concepts of modem sampling theory. A sample is de- fined as a representative part or a single item from a larger whole, being drawn for purpose of inspection or shown as evidence of quality. In modem theory the sample is a part of a statistical population whose properties are studied to gain information about the whole. The theory of sampling is built around the concept that if enough representative units of a larger overall population are selected without bias, the average value of the units will approximate that of the total population. Modem theory attempts to answer the question of how many samples are enough, given certain limits and constraints, and seeks to apply methods of sample selection and of estimation that provide, at the lowest possible cost, estimates that are precise enough for the purposes at issue. In order to meet these objectives the designer of a sample survey must rely heavily upon statistical theory. Statistics has been defined as the collection, presentation, analysis, and interpretation of numerical data. Statistical methods are primarily concerned with making valid inferences about a population based upon samples taken from the population. For most statistical applications, the total sample is in terms of number of items, attributes, or things; whereas mineral samples are usually in terms of weight or volume of mineral particles. Certain steps are involved in a well designed sample survey without regard to the particular field of application. Because the desired characteristics of an unmined mineral deposit can- not be known other than by sampling, we will consider these principle steps in terms of a mineral sample survey: 1) Clear definition of the objectives of the survey. In the case of mineral sampling this step is so apparent as to be almost ridiculous. However, it is surprising how often the overall objective of a sampling program is overlooked when decisions are made on a day-today basis. 2) Definition of the population to be sampled. The word population is used to designate the aggregate from which the sample is chosen. A sampling program may be designed to determine the grade of a single stope within a mine, the grade of a particular zone within a complex ore body, or the total value and extent of a mineral deposit. Since mineral sampling is usually done in phases, it is well to

Jan 1, 1980

By George Stone

THE method of making oxide of zinc direct from the ore was invented and developed at the works of The New Jersey Zinc Co. at Newark in the middle of the last century. The process was invented by Burrows, who had not the ability, financial or technical, to work out the details necessary to make it of commercial value. This was done by Col. Wetherill, whose name is commonly attached to this process. The, grate bars used are also frequently called Wetherill grates, which is a misnomer because they were in common use for boiler firing at the time and he never claimed their invention. The invention of the process was due to the efforts of The New Jersey Zinc Co. to find a profitable means of working the ores from Franklin and Sterling Hill, N. J. These are a mixture of franklinite, willemite and zincite, containing about 20 per cent. of zinc. The first attempts were to make spelter, which were not successful, owing to the low grade of the ore and the fusibility of the residue. Failing in this, the next attempt was to make oxide in large muffles and reverberatory furnaces. This succeeded, although the cost of operation was high, the recovery low, and the quality of the product uncertain. In 1855, the new process was patented and has been in successful operation ever since. Essentially, the process is to spread a mixture of coal and ore on a body of burning coal on a perforated grate and blow an excess of air through the grate. The zinc is reduced in contact with the coal, volatilizes and burned by the excess of air in the upper part off the furnace and in the flues. It is then carried to the hag rooms by the excess air and products of combustion which are forced through the flues by fans. In its main features, the process is the same today as at the time of its invention, but the details have been so modified that it would hardly be recognized by its originators.

Jan 9, 1917

By Frederick N. Rhines, Robert F. Mehl

Relatively few data have been collected on the rates of diffusion in ternary solid solution systems. In general it does not seem worth while to gather extensive data for such systems until the factors that determine the rates of diffusion in binary systems are better understood. But the rates of diffusion in a ternary system of limited solid solubility, in which the terminal solid solution is in equilibrium with an intermediate phase and may thus be represented as a quasibinary system, represents a case of special interest. In this case, where by reason of the association of the two solute metals in an intermediate phase a special attraction of the two solute atoms may be safely assumed, some interaction of these atoms during simultaneous diffusion in the solvent lattice might be expected. It has frequently been proposed that molecular solid solutions exist in quasibinary and in other ternary (and binary) solid solutions. There is no direct evidence for such solid solutions; arguments based upon the supposed anomaly in certain physical properties1 are hardly important; unexpected density relationships have proved deceptive;2 suggestions of molecular solid solutions have been made on the basis of solution laws in their application to certain systems, but without result;3 attempts to find lattice parameters in the solid solution Al-MgZnz, which cannot be calculated from the separate effects of magnesium and zinc and might therefore be taken as evidence for a molecular aggregation, have given negative results.* Fundamentally, methods for the determination of the state of molecular aggregation in solution depend upon the kinetic behavior of the particles constituting the system. If it could be shown that the two solutes in a quasibinary ternary system diffuse in molecular proportions, despite a radical difference in the separate rates of diffusion of each solute when diffusing alone in the solvent lattice, some basis for the concept of molecular solid solution would be afforded. Freche5 examined the rates of

Jan 1, 1940

By Frederick N. Rhines, Robert F. Mehl

Relatively few data have been collected on the rates of diffusion in ternary solid solution systems. In general it does not seem worth while to gather extensive data for such systems until the factors that determine the rates of diffusion in binary systems are better understood. But the rates of diffusion in a ternary system of limited solid solubility, in which the terminal solid solution is in equilibrium with an intermediate phase and may thus be represented as a quasibinary system, represents a case of special interest. In this case, where by reason of the association of the two solute metals in an intermediate phase a special attraction of the two solute atoms may be safely assumed, some interaction of these atoms during simultaneous diffusion in the solvent lattice might be expected. It has frequently been proposed that molecular solid solutions exist in quasibinary and in other ternary (and binary) solid solutions. There is no direct evidence for such solid solutions; arguments based upon the supposed anomaly in certain physical properties1 are hardly important; unexpected density relationships have proved deceptive;2 suggestions of molecular solid solutions have been made on the basis of solution laws in their application to certain systems, but without result;3 attempts to find lattice parameters in the solid solution Al-MgZnz, which cannot be calculated from the separate effects of magnesium and zinc and might therefore be taken as evidence for a molecular aggregation, have given negative results.* Fundamentally, methods for the determination of the state of molecular aggregation in solution depend upon the kinetic behavior of the particles constituting the system. If it could be shown that the two solutes in a quasibinary ternary system diffuse in molecular proportions, despite a radical difference in the separate rates of diffusion of each solute when diffusing alone in the solvent lattice, some basis for the concept of molecular solid solution would be afforded. Freche5 examined the rates of

Jan 1, 1940

By John M. Hartman

An examination as to irregularity of wear around the nose of the Witherbee tuyeres showed a section through the nose near the top as per Fig. 1, and a section only a half-inch beyond as per Fig. 2. The molten iron flowing over the nose of the tuyere had melted off the metal until the water in the tuyere prevented further melting. These tuyeres have a division in the annular water-space (see Fig. 2) to turn the current of water at the top, and the watersupply pipe is carried to within 1 inch of the nose. The constant supply of cold water in the nose of the tuyere kept it well cooled and preserved. But half an inch on the other side of the division the metal had melted off, as is shown by Fig. 1. There was no means of effecting a circulation at this point so long as the water was discharged from the butt of the tuyere. A pipe having been placed on the discharge-side of the division, the same as on the supply-side, in order to secure a circulation of the water at the nose on the discharge-side, it was found that the metal did not burn off. The nose being found to give out at the bottom, a division was placed in the annular water-space at the bottom, terminating 1 inch from the nose. This made a sharp current of circulation in the nose at the bottom, and prevented the burning of the metal there. A positive circulation at the nose, top and bottom, is a necessity with the present fast driving of furnaces, and prolongs the life of the tuyeres. The proper metallic composition of tuyeres is a question constantly agitated. A trial of ordinary yellow-metal* tuyeres was made 12 years ago. They did their work just as well

Jan 1, 1899