bluuebunny/crossref_metadata_2025 huggingface dataset:
PETROLOGY AND SILICATE TECHNOLOGY*
Authors: Bowen Norman L.
Published: June 2006

Abstract

Petrology is concerned with the rocks and mineral deposits of the earth's crust. Like all natural sciences, it developed through a descriptive stage in which the principal emphasis was placed on the collection and correlation of facts. Interpretation recently has been increasingly stressed, and it has been realized that to reach reliable conclusions regarding the origin of earth materials experiment is an indispensable aid.

The petrologist, acting on this conviction, has studied the behavior of various earth materials subjected in the laboratory to a wide range of temperatures, pressures, and chemical environment. He has thus been enabled to reach certain conclusions regarding the conditions to which these materials wfere subjected during the natural processes by which they were formed. Inevitably he discovered a great many facts of service to the mineral technologist.

Some of the industrial processes developed by the mineral technologist have in return served to supplement the laboratory experiments of the petrologist. Some aspects of this mutual service of mineral technology and petrology are discussed.
OBSERVATIONS ON SOLID‐PHASE INVERSIONS OF CALCIUM ORTHOSILICATE, CONSTITUENT OF DOLOMITE‐SILICA BRICK*
Authors: And Samuel Zerfoss , Davis H. M
Published: June 2006

Abstract

The solid solution of P2O5 in calcium orthosilicate, 2CaO† SiO2, was studied by means of thermal and optical methods, and the inversion temperature for the alpha to beta 2CaO.SiO2 change was found to be lowered by the presence of the dissolved P2O5.

With this information concerning the solid solution of PaO5 in the high‐temperature forms of 2CaO.SiO2, a probable mechanism is presented for the inhibiting effect of P2O5and similar oxides on the beta‐gamma inversion (dusting) of 2CaO . SiO2. Two new crystal chemically inhibiting oxides (As2O5, V2O5) are listed.

The types of inhibition of the beta‐gamma inversion are distinguished as (1) physical, wherein the constraint imposed by the surroundings acts to prevent the inversion, isolate the grains of 2CaO . SiO2, and interrupt the continuity of the inversion wave, and (2) crystal chemical, wherein the presence of foreign dissolved substances apparently produces a true stability in the beta lattice at room temperature. The mechanism of the crystal‐chemical inhibition is discussed in some detail. The information is applied to the problem of stabilizing 2CaO . SiO2 in dolomite or lime‐silica brick.
USE OF ALUMINUM METAL IN THE CERAMIC INDUSTRY: II, EFFECT OF COATING INSULATING FIREBRICK WITH ALUMINUM‐FIRE‐CLAY MIXTURES*
Authors: Schurecht H. G. , McMahon J. F.
Published: June 2006

Abstract

After insulating firebrick are reheated in service, many of them contract too much and develop large open shrinkage cracks. By first applying to the surfaces a 0.035‐in. coating composed of aluminum and fire clay, these brick usually remain intact and constant in size when they are reheated. The coating also becomes hard, causing the brick to become more resistant to abrasion, slag action, permeability of gases, load at high temperatures, and sudden temperature changes. Coatings composed of 60 to 70% of fire clay and 30 to 40% of aluminum powder were found to overcome most of these deficiencies in insulating firebrick.
STUDY OF LITERATURE ON SEPARATION OF MAGNESIA FROM LIME IN DOLOMITE AND SIMILAR MATERIALS*
Authors: Seil Gilbert E. , Staff
Published: June 2006

Table OF Contents

I, Introduction. II, Physical Extraction: (1) classifying, (2) calcination, (3) hydration, (4) leaching, (5) flotation, (6) crystallization, and (7) miscellaneous physical methods. III, Chemical Extraction: (1) forming carbonates and formates, (A) carbon dioxide, (B) carbonates, and (C) carbon monoxide; (2) chlorine compounds, (A) chlorine, (B) hydrochloric acid, (C) calcium chloride, (D) magnesium chloride, (E) cyclic process, (F) hydrochloric acid manufacture; (3) nitric acid; (4) sulfur compounds, (A) sulfuric acid, (B) sodium sulfate, (C) sodium bisulfate, (D) calcium sulfate, (E) magnesium sulfate, (F) sulfur dioxide, (G) sulfites, and (H) sulfur, sulfides, hydrogen sulfide; (5) ammonia and ammonium salts; (6) alkalis, (A) calcium hydroxide, and (B) sodium hydroxide; (7) organic compounds, (A) acetic acid, and (B) sugar; (8) sea water, (9) electrochemical methods; (10) ion exchange, (11) miscellaneous chemical methods. IV Miscellaneous. V. Conclusions VI, Bibliography VII, Author Index.
REACTIONS IN SOLID STATE: 111, REACTION BETWEEN SODIUM CARBONATE AND QUARTZ*
Authors: Gibsont George , Ward Roland
Published: June 2006

Abstract

Reactions of sodium carbonate with quartz occur without fusion between 726° and 805°C. When the reactions are conducted in a stream of nitrogen, the size of the charge, composition of the mixture, rate of flow of gas, and duration of reaction have appreciable effect on the reaction rates and on the nature of the product.

In presence of sufficient sodium carbonate, the end product of the reaction at the higher temperatures is the orthosilicate. The formation of a series of silicate ions as rntermediate products between the metasilicate and the orthosilicate by interaction of the former with carbonate ions is postulated. This process is considered to be reversible with the smaller silicate ions. This theory, moreover, serves to reconcile several apparent anomalies in the experimental data.

The rate of reaction of thc silica particle is not measured by the rate of carbon dioxide evolution.
EFFECT OF COMPOSITION AND TEMPERATURE ON SOLUBILITY OF IRON OXIDE IN GROUND‐COAT ENAMEL GLASS*
Authors: Andrews A. I. , Swift Howard R.
Published: June 2006

Abstract

The solubility of iron oxide in ground‐coat enamel glasses at various temperatures was studied by adding varying amounts of ferric oxide to the milled enamel and giving the mixture a heat‐treatment to acquire uniformity without devitrification at the desired temperature. The iron oxide solubility was obtained by finding the breaking point in the curve for iron oxide versus index of refraction. The frit solubilities were obtained at 1400°, 1600°, 1800°, and 2000°F. with variations in Na2O, B2O3, A12O3, CaF2, CaO, F2, SiO2, COO, NiO, MnO2, BaO, and MoO3. Data are given on a number of commercial frits.
VERMICULITE AS A RAW MATERIAL IN CERAMIC MANUFACTURE*
Authors: Pence F. K. , Blount E. B.
Published: June 2006

Abstract

Expanded Vermiculite has been studied for use with a low vitrifying plastic clay bond to form structural clayware, such as partition tile and bathroom tile, which may carry glazed coatings in decorative effects. The advantages of this material are its low thermal conductivity, its relatively high strength as compared to its specific gravity, and the ease with which it can be cut and fitted into installations.
AGING THERMOMETERS*
Authors: Taylor Nelson W. , Noyes Bradford
Published: June 2006

Abstract

During the long‐time aging of thermometers at constant temperature, the change in readings of a fixed point, such as the ice point, normally follows an exponential law, y= a(1 –e‐mt). Methods are described for the evaluation of the total expected change, a, of the relaxation time, l/m, and of the half‐life period, H= 0.693/m. Examples are given and calculations are made of the expected change remaining after any aging time, t. It is believed that the exponential law is due primarily to bulb shrinkage under the influence of a single molecular mechanism in the glass. Some examples are presented of anomalous behavior, such as reversals in the direction of change. This phenomenon is shown to be a general one in glass, and an interpretation is given in terms of several molecular processes which operate at one time but with different characteristic rates. An expression is derived for the calculation of change of density in glass, based on experiments in which the glass is in the form of a thermometer. The methods of mathematical analysis described in this paper are useful for evaluating the effects of accelerated aging treatments on glass.
PRACTICAL PRODUCTION OF ONE‐FIRE LUSTER GLAZED POTTERY*
Authors: Burnham Forrest , Harder Charles M.
Published: June 2006

Abstract

Various metals in small quantities, singly and in various combinations, were ground in lead and leadless glazes. It was found that various colored lusters, transparent and opaque, could be reproduced under a fair degree of control in an ordinary downdraft gas‐fired sagger kiln, which was fired from cones 010 to 1. After cooling to a dull red heat, the glazes were given a short reduction firing. Standard decorative processes were used with the luster glazes. Additional colors were produced by adding stains and metal oxides. Acid‐resistant luster glazes were developed.
BRUCITE MAGNESIA *
Authors: Goudge M. F.
Published: June 2006

Abstract

A discussion of the occurrence of brucite in limestone, the method of extracting it in the form of magnesia, and uses for which this particular type of magnesia is best suited is presented with emphasis on the possibilities of brucite magnesia in the ceramic industry.
CHANGES OF PROPERTIES OF GLASS RESULTING FROM CHANGES OF COMPOSITION *
Authors: Huggins Maurice L. , Sun Kuan‐Han
Published: June 2006

Abstract

Equations are given for the calculation of changes of density, refractive index, and other optical constants produced by the addition of a known relative weight of a given component to a base glass. Corresponding equations for the substitution of one component for another are also given. Values are computed and listed for the initial fractional rate of change of refractive index (nD) when various components are added to (a) pure SiO2 and (b) a sodium silicate glass containing 50% of Na2O by weight.
ENAMEL FILM STRENGTH AS AFFECTED BY PROPERTIES OF ENAMEL BEFORE, DURING, AND AFTER DRYING *
Authors: Blanchard M. K. , Andrews A. I.
Published: June 2006

Abstract

The effect of soluble salts in porcelain enamel mill liquors was investigated, particularly relating to the enamel film strength and tearing tendency. The mechanism of tearing is discussed from the standpoint of the properties of the enamel slip and of dried enamel film. The related data are presented, and the application of the results of recent extensive studies of clay, water, and electrolyte systems to enamel slips is given.

The results of this investigation may be summarized in a flow sheet in which the various properties and conditions governing these properties are related to the characteristics studied. Figure 9 lists each variable in the sequence considered logical in this study.
CONVERSION OF CERTAIN REFRACTORY OXIDES TO A SUBOXIDE FORM AT HIGH TEMPERATURES *
Authors: Zapffe C. A.
Published: June 2006

Abstract

A preliminary survey of the information published in the fields of chemistry and physics on the suboxide forms of SiO, TiO, ZrO, CrO, AlO, BO, VO, and CbO indicates a new field to be explored in determining the role of these suboxides in the service and failure of refractories and in the chemistry of slags. Several phenomena at the present time little understood, such as devitrification in reducing atmospheres, volatilization of refractory oxides, and certain slag types now classed as anomalous, may find their explanation in the decomposition of the oxides to low oxide forms under the favorable conditions of high temperature and low oxygen pressure which characterize much of their service.
SIGNIFICANCE OF TOPOCHEMICAL FACTORS ON RATE OF REACTIONS BETWEEN SOLID SALTS *
Authors: Cohn Gunther
Published: June 2006

Abstract

The factors determining the rate of reactions between solids are discussed. When the solid phases are internally in equilibrium and when equilibrium also is established at the phase boundaries, the kinetics are given by the geometric dimensions of the system, the free energy decrease, and the mobility of the diffusing particles in the reaction product. These conditions are not fulfilled in most practical cases, the reactions being strongly dependent on topochemical factors. Topochemical imperfections in crystals and their influence on the reaction velocity are described, but the mechanism of reactions influenced by topochemical factors can only be found empirically. The way of approach is outlined for the case of spinel formation from zinc oxide and iron oxide.
PARTICLE SHAPE AND DIFFERENTIAL SHRINKAGE OF STEATITE TALC BODIES *
Authors: Lamar Richard S.
Published: June 2006

Abstract

An attempt has been made to correlate the differential shrinkage of fired steatite pieces with the particle shape of the raw talc used in their manufacture. Various talcs of widely varying particle shape were used in making the steatite test pieces. It was found that the more irregular in shape the talc particles, the greater the differential shrinkage.

A method is given for assigning arithmetical values to various particle shapes depending on their deviation from sphericity, this arithmetical value being known as specific shape factor. A direct relationship was found to exist between the differential shrinkage of a talc and its specific shape factor. As the talc particles became more irregular in shape, the “specific shape factor” value increased and the differential shrinkage was found to increase. The proper selection of the talc td be used and blends of various talcs were found to be helpful in the control of differential shrinkage.
PARTICLE‐SIZE DISTRIBUTION OF STEATITE TALC *
Authors: White J. S.
Published: June 2006

Abstract

Experiments were made to determine which degree of fineness of ground talc would be most suitable for steatite‐type ceramics. A laboratory‐type air separator, Andreasen pipette, and the Casagrande hydrometer methods were used to measure the particle‐size distribution of commercial steatite talcs.

The results indicate that, although wide variations in the particle‐size distribution of steatite talcs have a bearing on the firing shrinkage when the talc is incorporated in a body, the differences in grinding obtained in commercial talcs are not of great importance when proper milling practice is employed.
FUSION EXPERIMENTS IN SYSTEM MgO‐FeO‐Cr2O3‐Al2O3*
Authors: Baumann Henry N.
Published: June 2006

Abstract

Various methods have been suggested and tried for modifying chrome ores for refractory use. Chrome ores vary widely in chemical composition but are made up chiefly of MgO, Al2O3, FeO, and Cr2O3 combined as a member of an isomorphous spinel‐type series. The problem of modifying chrome refractories by chemical and thermal treatment therefore involves a knowledge of the system MgO‐FeO‐Cr2O3‐Al2O3. The present study is based on experiments in which two series of chromium oxide‐alumina fusions containing 10% and 30% Cr2O3, respectively, were fused in an electric‐arc furnace with MgO up to 5% and with FeO up to 5%. The determination of the effect of silica and titania on the primary crystallization of these fusions, as indicated by a petrographic method of examination, was the chief purpose of this work.
OBSERVATIONS INDICATING ABSENCE OF PLASTIC FLOW IN GLASS COATING ON STEEL *
Authors: Martin W. G. , Lauck F. W.
Published: June 2006

Abstract

Steel rings were glass coated, and some were split at one point immediately and others one or two years later. Identical movement of the rings caused by compressive forces in the glass indicated that no plastic flow takes place in the glass. The compressive forces were calculated and found to be of the general order of 10,000 Ib. per sq. in. The method of calculation is described.

VI. Summary

(1) Equal contraction of glass‐coated steel rings cut immediately after firing and those cut one and two years later indicates no plastic flow of the glass coating.

(2) Calculations indicate a compressive stress of 10,900 lb. per sq. in. in the glass coating.

(3) No definite explanation is advanced for the absence of plastic flow under such stress values except the suggestion that the cross‐section dimensions of the glass and relatively large surface area may account for restraining forces.
NOTES ON MOISTURE EXPANSION*
Authors: Thiemecke H.
Published: June 2006

Abstract

Moisture‐expansion determinations were made over a period of more than three years on bisque and glazed specimens of two types of semivitreous bodies having approximately the same absorption which were exposed to four different atmospheric conditions. The data indicate the cone 0 tale‐pyrophyllite body to expand less under all conditions of exposure than the cone 9 clay‐flint‐feldspar body. Glazed specimens of both bodies expanded more than the bisque specimens and a possible explanation is given. From mathematical considerations, a three‐year storage period appears to be sufficient to permit moisture expansion that closely approaches the ultimate which might be expected in the types of bodies investigated. The autoclave treatment gave the highest expansion values and should serve as an index of the service performance as to delayed crazing of ware so tested.
DIFFERENTIAL THERMAL ANALYSIS OF CLAYS AND SHALES, A CONTROL AND PROSPECTING METHOD*
Authors: Grim R. E. , Rowland R. A.
Published: June 2006

Abstract

The differential thermal method, by determining the thermal reactions undergone by a clay or shale, is a rapid means of identifying the mineral components of such materials, and because the properties of clays and shales depend largely on their mineral composition, it is at the same time a rapid method of evaluating the properties of such materials.

Differential thermal analyses are presented for the pure forms and synthetic mixtures of the common components of clays and shales, namely, kaolinite, halloysite, illite, montmorillonite, quartz, gibbsite, boehmite, diaspore, dolomite, calcite, gypsum, organic material, pyrite, marcasite, goethite, and limonite.

Differential thermal analyses are presented also for a variety of well‐known types of clays, and on the basis of the thermal data for the pure components, the mineral composition is indicated. The correlation of mineral composition of clays and shales (as reflected in the differential thermal curves) with the ceramic properties is discussed as a basis for using this thermal method to indicate the properties of such materials.

Finally, differential thermal analyses are presented for sequences of samples from the pits of several operating clay products plants in order to illustrate the way in which the method can be applied in prospecting and in plant control.
DEVITRIFICATION CHARACTERISTICS OF ALKALI‐LEAD OXIDE‐DOLOMITE LIME‐SILICA GLASSES*
Authors: White J. F. , Silverman W. B.
Published: June 2006

Abstract

The devitrification characteristics of the field of compositions, which includes the commercial lime crystal glasses, were investigated. Tridymite was found to crystallize from glasses containing as low as 62% of SiO2. Tridymite, devitrite, diopside, sodium disilicate, and an unidentified compound were found to be primary phases. Potassium oxide (K2O), in general, lowers the liquidus temperature when it replaces Na2O.
OPTICAL FLUOR‐CROWN GLASSES*
Authors: Fraser Walter A. , Upton Lee O.
Published: June 2006

Abstract

The effect of variations in composition on optical properties was studied. The index of refraction is lowered by the substitution of fluorine and alumina for silica; the reciprocal dispersion, however, is increased by fluorine and lowered by alumina so that fluorine and alumina can be balanced against each other to give almost any desired optical properties within the field investigated, that is, in the range of 1.46 to 1.50 for index of refraction and 63 to 70 for the reciprocal dispersion.
VISCOSITY OF RECENT CONTAINER GLASS*
Authors: Robinson Howard A. , Peterson Charles A.
Published: June 2006

Abstract

A high‐temperature, concentric cylinder viscometer has been constructed and calibrated. The calibration checks within 1% that obtained by Lillie for a similar apparatus and provides further evidence of the high degree of reliability of this type of measurement. The contention of Washburn and Shelton that the calibration in such instruments is a function of the viscosity is shown to be false. Because four independent investigations have been unable to check this contention, it may now be regarded as spurious. A medium temperature‐range fiber viscometer for measuring the viscosity of glass in the annealing range has also been constructed. It is shown that the Fulcher equation, log η=−A+B/T−T0, fits the data obtained on the two instruments to within 0.5% for commercial soda‐lime glasses. Complete viscosity data as a function of temperature are given for sixteen commercial container glasses, and the analyses are also included. These glasses show a wide range of viscosity.
ANALYSIS OF CORDS AND STONES*
Authors: Zarbo G. J. , Hunt H. J. , Smith D. C.
Published: June 2006

Abstract

A method is described for the separation of cords and stones from the surrounding glass, and procedures are given for the semimicro‐determination of silica and alumina. The apparatus is illustrated. Analytical results by full‐scale methods and semimicro‐methods are given. The methods of semimicro‐analysis are shown to be rapid and accurate.
SURFACE TENSION AND PERSISTENCE OF CORDS IN GLASS*
Authors: Knight Mellen A.
Published: June 2006

Abstract

The action of surface tension in molten glasses is discussed in relation to cord persistence. An examination is made of the reported mechanism for the solution of cords as proposed by Jebsen‐Marwedel. His viewpoint that the shape of immersed cords is governed by surface‐tension differences between the cord and matrix glasses appears to be in conflict with the physics involved. The possible influences of inter‐facial tension on the shape of cords and on their location in or on the melt are considered along with its relation to other physical forces. It is concluded that the only stable form for cords under the influence of interfacial tensions alone is a spherical one. Other factors, such as high viscosities, varying diffusion rates, and mechanical and thermal stirring cause the irregular shapes found in practice. The relation of surface tensions to these factors requires further study.
SURFACE LAYER OF SHEET GLASS*
Authors: Bishop F. L.
Published: June 2006

Abstract

This research was conducted to obtain evidence of the nature of the fire polish on sheet glass. Three measurements were made on each sample as follows: (1) The deviations from Fresnel's reflection laws, (2) a measurement based on the Pfund method of determining the apparent Brewsterian angle as compared to that calculated from the index of refraction of the glass, and (3) the true index of refraction by a prism method in which the samples were cut and ground to 60‐degree prisms. These measurements showed that freshly drawn sheet glass probably has a crystalline layer several molecules thick on the surface. The layer has a high index of refraction, but this is counteracted quickly by water absorption if the glass is dampened slightly or is exposed to the atmosphere.
CALCULATION OF SURFACE TENSIONS OF GLASSES*
Authors: Lyon K. C.
Published: June 2006

Abstract

Factors have been derived for the calculation of the surface tensions of glasses from their compositions at temperatures of 1200° and 1400°C. The nine oxides evaluated are those commonly found in significant amounts in glass compositions. The surface tension of a glass may be calculated with a fair degree of assurance from its composition to within about 4 dynes per cm.
OPTICAL GLASS FROM THE VIEWPOINT OF THE LENS DESIGNER*
Authors: Kingslake R.
Published: June 2006

Abstract

The glass used in the manufacture of lenses must be chemically stable and substantially free from bubbles, color, and striae. The lens designer is then concerned only with the refractive index and the dispersive power of the available glasses. Because practically every new lens must be achromatic, the positive elements used in it must be made from glass having a low dispersive power; the negative elements must have a relatively high dispersive power. The choice of refractive index is determined by many conflicting factors because the only “tools” available to the designer for the correction of many different aberrations are the radii of curvature of the lens surfaces, the thicknesses and air spaces, and the refractive indices of the glasses. The range of optical glasses commercially available and the reasons underlying the designer's selection of glass for different kinds of lenses are discussed.
II, CORRELATION OF GLAZE THICKNESS WITH AIR PERMEABILITY*
Authors: Harman C. G. , Blanchard M. K.
Published: June 2006

Abstract

An attempt was made to correlate the thickness of deposition of glazes with the air permeabilities of the bodies. The correlation was satisfactory under certain restricted conditions but not for general cases. An adequate correlation was obtained, independent of the type of body, between thickness of glaze deposition, glaze consistency (coherence value), and water receptivity.
SUGGESTIONS FOR SOLUTION OF DIFFICULT GLAZE‐FIT PROBLEMS*
Authors: Harman C. G.
Published: June 2006

Abstract

The methods and principles are discussed by means of which suitable glazes for special purposes may be prepared. Examples are given of glazes for low‐expansion bodies and also of durable low‐temperature glazes.
SOME FACTORS AFFECTING THE P.C.E. OF SILICA FIRE CLAY*
Authors: Birch Raymond E. , Hall Morris P.
Published: June 2006

Abstract

A study was made of the factors affecting the pyrometric cone equivalent (P.C.E.) of silica fire clay made of ganister, clay, and silica‐brick culls. These factors include grind, mix proportions, and quality of raw materials.
HIGH‐ALUMINA CLAYS OF PULASKI AND SALINE COUNTIES, ARKANSAS*
Authors: Tracey Joshua I.
Published: June 2006

Abstract

Extensive deposits of kaolinitic clay and closely associated bauxite occur in Pulaski and Saline counties, Arkansas, as products of early Cenozoic weathering of nepheline syenite. The clays of the bauxite‐kaolin deposits normally contain more than 35% of alumina. Siderite is the principal impurity. The deposits for the most part are buried beneath sediments of Wilcox age or younger, but the overburden is thin or absent near outcrops of syenite. Deposits beneath overburden that does not exceed 50 feet in thickness probably total more than 100 million tons.
PROPERTIES OF ENAMEL SLIPS: I, GENERAL PROPERTIES OF CLAYS AND ENAMEL SLIPS*
Authors: King Burnham W. , Carter Herbert D. , Draker Harry C.
Published: June 2006

Abstract

Five clays used to suspend porcelain enamels and their properties were studied. Fundamental data were first obtained on the clays, which were then milled in different proportions with several types of porcelain enamel frits. The properties of the resulting slips were studied. The pickup weight, that is, the amount of enamel retained on a ground‐coated plaque which had been dipped in the slip and allowed to drain, was used as a basis of comparison.
SUBSTITUTION OF TOPAZ, DOMESTIC KYANITE, AND SYNTHETIC MULLITE‐CORUNDUM FOR INDIA KYANITE: IV, RAW TOPAZ AS HIGH‐TEMPERATURE BOND FOR DOMESTIC KYANITE*
Authors: McVay T. N. , Galbreath W. W. , Allen Dan
Published: June 2006

Abstract

Raw topaz has been found to act as a high‐temperature bond for both raw and calcined kyanite. It is thought that this bonding action is due in part to volatiles which emerge from the raw topaz between 1000° and 1200°C. Some of the topaz decomposition products are absorbed and retained by the calcined kyanite. Within the limits of this investigation, all refractories which contained either calcined or raw kyanite, or mixtures of the two, with a minimum of 10% raw topaz had a good structure and were well bonded. The results of the load tests indicated that increased firing temperatures in the preheat improved the load resistance, but excellent high‐temperature resistance was obtained by preheating as low as 1300°C. in laboratory kilns.
VARIATIONS OF REFRACTIVE INDEX OF GLASS WITH TIME AND TEMPERATURE IN ANNEALING REGION*
Authors: McMaster Harold A.
Published: June 2006

Abstract

The refractive index of a rapidly cooled fiber of borosilicate glass was found to increase according to the equation, 1/(N6–N) – 1/(N6–N0) =At, where t is time, N6 is equilibrium index, and A is a constant at constant temperature. Index data were plotted according to this equation to determine, graphically, values of N6 and A for several temperatures between 914° and 1060°F. Values of N6 for temperatures from 1060° to 1180°F. were determined by prolonged heating of the glass at each 20° interval. The change of A with temperature was found to be well represented by the equation, log A=K/T+C, where T is the absolute temperature and K and C are constants.
SOFTENING POINT OF GLASS BY FIBER ELONGATION METHOD AND IMPROVEMENTS IN APPARATUS AND PROCEDURE*
Authors: Falter Arthur H.
Published: June 2006

Abstract

Detail and assembly illustrations show how the apparatus has been redesigned to maintain a constant rate of heat transmission. A description of the comparator telescope and the method of use is given. Individual curves show the results of softening‐point tests on glasses over a range of 260°C., in which the agreement for five individual homogeneous glass specimens varies from 1° to 6°C. when the ordinary portable potentiometer is used. When the glass contains stones or is devitrified, the results are more widely divergent. Uniformity of specimen diameter has a slight effect on the results.
LEWIS ACID‐BASE THEORY APPLIED TO GLASS*
Authors: Sun Kuan‐Han , Silverman Alexander
Published: June 2006

Abstract

According to the Lewis theory of acids and bases, glass formers, such as SiO2, B2O3, P2O5, BeF2, GeS2, etc., may be classified as acids because they are electron‐pair acceptors in glass reactions and the modifiers, Na2O, CaO, NaF, Na2S, etc., are bases because they are electron‐pair donors; Al2O3, Fe2O3, BeO, MgO, ZnO, etc., the intermediates, may be classified as amphoteric.
SOME PROPERTIES OF SODA‐SILICA GLASSES AT HIGH TEMPERATURES*
Authors: Sun Kuan‐Han , Safford Hurd W.
Published: June 2006

Abstract

A study is made of density, expansion, surface tension, parachor, and viscosity data for glasses in the system Na2O‐SiO2 within the temperature range 900° to 1400°C. The best values have been selected and correlated with composition.
TECHNOLOGICAL DEVELOPMENT OF POTTERY IN NORTHERN SYRIA DURING THE CHALCOLITHIC AGE*
Authors: Matson Frederick R.
Published: June 2006

Abstract

The techniques of manufacture and decoration employed by the potters living on the Plain of Antioch from about 4500 to 2000 b.c. are summarized on the basis of evidence obtained from a laboratory study of the pottery and the local clays.
EFFECT OF MIGRATION OF CLAY MINERALS AND HYDROUS ALUMINUM OXIDES ON THE COMPLEXITY OF CLAY*
Authors: Allen Victor T.
Published: June 2006

Abstract

Movement of montmorillonite, nontronite, kaolinite, halloysite, dickite, gibbsite, and diaspore within clays after they were first formed is indicated by the relations reported in this paper. Migration of these minerals takes place rarely by transfer of their constituents as true solutions but generally as colloidal suspensions whose formation and movement are favored by conditions of good drainage and the presence of dispersing agents. This migration increases the complexity of the clays affected by it and accounts for some of the variations in the composition of a single body of clay met by the clay producer.
CRAZING OF ENAMEL ON STOVE TOPS DUE TO HEATING IN SERVICE*
Authors: Fellows Roger L.
Published: June 2006

Abstract

Examination of stove tops that had crazed in service show two types of crazing. One is in the form of a network of cracks which may be attributed to thermal shock, while the other is in the form of parallel lines and occurs in the normal use of the stove without any particular abuse. In studying the latter type of failure, localized heating of the stove top causes a cross‐bend failure of the enamel due to flexing from the heat, and the higher the temperature the less is the amount of deflection required to cause failure. The temperature necessary for this condition is lower than 550°F. Sample plates subjected to various tests afforded a means of studying the different variables that produce crazing in stove tops.

From these tests, the following observations are made: (1) Stove tops that have tensile strains in the enamel due to fabrication or assembly are likely to craze in the areas of these stresses if they are heated; (2) the lower the coefficient of expansion of the cover‐coat enamel, the less likely is the enamel to craze; (3) the lighter the weight of application of cover coat, the greater is the resistance to crazing; (4) the heavier the gauge of metal the greater is the resistance to crazing; and (5) heating the enamel over a long period of time tends to induce crazing.
ANNEALING STRAINS IN GLASS AND THEIR DEGREE OF PERMANENCE*
Authors: Ghering L. G. , Green T. D.
Published: June 2006

Abstract

A statistical comparison has been made of 13 sets of measurements of optical path difference, taken over a seven‐year period, on 24 samples of the standardized disks distributed in 1938 to the manufacturers of glass containers. These data show that the original optical retardation of about 22.8 millimicrons has not changed by more than =1.3%, equivalent to =0.30 millimicron or =0.10° on the scale of the measuring instrument.

Five tests were made in 1938, five in 1945, and three between. The standard deviation of the combined errors for each of the 13 averages of 24 measurements is =0.0338° and is composed of an accidental error of observation of =0.005° and an error of adjustment of the instrument of =0.0333°. The range of =1.3%, or =0.10°, beyond which the disks could not have changed over seven years, represents the 3‐sigma probability limit of combined errors.

While this possible change of =1.3% would be insignificant in relation to the utility of the standardized disks, it represents a possible experimental error too great to permit broad conclusions concerning the ultimate stability of birefringence in strained glass.
GLASS DENSITIES BY SETTLING METHOD*
Authors: Knight Mellen A.
Published: June 2006

Abstract

A simplified sink‐float apparatus and method for measuring the densities of lumps of glass are described. Several lumps, of approximately two grams weight, of unknown density and one lump of glass of known density are placed in a heavy‐liquids mixture contained in a test tube. The tube is immersed in a water bath that is heated automatically at a uniform rate; as the lumps settle, the temperature is noted at which each lump passes a reference line marked on the tube. The density of each unknown may be expressed simply in terms of the difference between its temperature and that for the standard lump, or these temperature differences can be converted to density differences or to absolute densities. The precision (reproducibility) of the measurements is represented by a standard deviation of approximately =0.0001 gm. per cc.

The method is rapid and convenient and requires a minimum of training of the operator. It is believed to be more practical for plant laboratories than the other available methods. It is especially applicable to measurement of daily densities for production control in glass plants and to trouble‐shooting investigations of composition heterogeneities; large numbers of samples can be tested rapidly and precisely. Complete information as to sampling, operation, and calculations is given.
TRACING FLOW IN GLASS TANK FURNACES*
Authors: Bishop F. L.
Published: June 2006

Abstract

By adding a small amount of a rare earth to a definite portion of batch, the velocity, direction, and amount of surface flow can be determined. The flow measurements are calculated from the resultant slight fluorescence of samples taken at intervals or by the change in transmission for certain wave lengths of ultraviolet light. Sample results are shown and discussed.
VISCOSITY STUDIES OF SYSTEM CaO–MgO–Al2O3–SiO2:1, 40% SiO2*
Authors: Machin J. S. , Hanna D. L.
Published: June 2006

Abstract

The measurement of glass viscosities at elevated temperatures with an oscillating cylinder‐type viscometer is described. Viscosity data are presented covering those compositions in the CaO–MgO–Al2O3–SiO2system which contain 40% SiO2and which are liquid at 1500°C. The pattern of the system of isokoms presented indicates that viscosity is closely related to the ratio of basic to acidic components. Theoretical aspects of the variation of viscosity with composition in silicate‐aluminate systems are discussed in terms of silica‐alumina polymers.
DETERMINATION OF REFLECTANCE OF WHITE ENAMEL FRITS BY TURBIDITY METHOD*
Authors: King R. M.
Published: June 2006

Abstract

A method for the determination of the reflectance of powdered frits is described. Results obtained by this method show a high correlation with the results of standard reflectance tests, particularly when frits are fused at enameling temperatures.

The method consists essentially of suspending 0.4 cc. of sample, sized between 270‐ and 325‐mesh, in 10 cc. of clear kerosene and measuring by means of a photoelectric cell the decrease in light transmitted as compared with the light transmitted by kerosene itself. The Cenco‐Sheard‐Sanford photelometer was used for these measurements.
COATINGS FOR WIRE‐WOUND RESISTORS*
Authors: Marbaker Edward E.
Published: June 2006

Abstract

This paper describes the experimental work carried out by the O. Hommel Fellowship, Mellon Institute, under a contract made by the O. Hommel Company with the War Production Board, to develop a coating for wire‐wound resistors which would pass the Grade 1, Class I qualification tests of Army and Navy Specification JAN–R–26. An outline of the methods used, a general survey of the types of coating considered, generalizations concerning requirements, and conclusions are presented.

The work included studies of the conventional enameled Nichrome‐wound, steatite tube resistors which consisted of an investigation of the properties of tubes made from steatite and other ceramic bodies and the testing of vitreous enamels formulated for use as resistor coatings.

When it became apparent that steatite tubes are not perfectly resistant to thermal shock and that the disparity among the expansivities of the component elements of this type of resistor is so great that the formulation of an enamel having satisfactory properties is very difficult, if not impossible, an extended effort was made to develop a resistor in which the wire was wound on a pre‐enameled steel core and then coated with a suitable cover‐coat enamel. Considerable progress was made on the enamel‐coating studies, but non‐short‐circuiting terminals were found to be necessary and a completely satisfactory design was not worked out except for testing purposes.

A resistor that fulfilled the requirements of resistance to thermal shock and moisture penetration was developed from a tube of zircon porcelain, wound with Kovar wire and coated with Pyrex‐brand glass, the expansivities of all of which are low and within a relatively narrow range. Except for the fact that the wire used in this combination has too high a thermal coefficient of resistance, this type of resistor is capable of meeting the Grade 1, Class I specification.

A recently developed silicone paste was applied to various types of tubes wound with a standard resistance wire fastened to copper tabs or to ferrules and cured at a maximum temperature of 375°C. This coating has a rubbery consistency and is not wet by water. Resistors coated with this material have fulfilled the requirements of Grade 1, Class I qualification tests.
LABORATORY CORROSION TESTS OF ROTARY LIMEKILN REFRACTORIES*
Authors: Pole Gordon R. , Beinlich Alfred W.
Published: June 2006

Abstract

A modification of the Hugill, Ainsworth, and Green laboratory method for determining the corrosive action of lime on refractories was used to indicate the best refractory for rotary limekilns. An intermediate handmade refractory, two high alumina, two superduty, and two first‐quality, stiff‐mud refractories were tested. It was found that the depth of penetration of the lime attack decreases with an increase in alumina content of the refractory. Better resistance of the 70% aluminous refractories to slagging was indicated by the small‐scale tests which were substantiated by plant‐scale operation.
FACTORS INFLUENCING FLUXING ACTION OF VARIOUS OXIDES IN LOW‐TEMPERATURE BOROSILICATE GLASSES*
Authors: Swift Howard R.
Published: June 2006

Abstract

Strontium, barium, and lead oxides were studied as fluxes in low‐temperature borosilicate glasses by using the button‐flow method. It was found that strontia may be superior to lead oxide as a flux in glasses high in fluorides and low in alumina. This result was explained by the greater solubility of fluorides in strontia glasses, in which case the two fluxes, strontia and fluorspar, are acting together.
EFFECT OF TEMPERATURE ON HOMOGENIZING RATE OF SODA‐LIME‐SILICA GLASS*
Authors: Tiede R. L. , Tooley F. V.
Published: June 2006

Abstract

Density‐spread determinations were made on a series of melts of a soda‐lime‐silica glass prepared at temperatures ranging from 1232° to 1454°C. for a four‐hour period in the absence of furnace refractory and under conditions of minimum convection mixing. A sharp drop in density spread in the range 1232° to 1288°C., a minimum at about 1325°C., and a slowly increasing density spread at temperatures above 1325°C. were observed.

The portion of glass responsible for the major part of the density spread was found to be concentrated in the top half of the glass at both 1232° and 1454°C. At the higher temperature, the improvement in the homogeneity of the bottom layer was more marked than that observed in the top layer as compared with the results obtained on the lower‐temperature melt. The density spread of the glass in the bottom layer in the case of the high‐temperature melt was in the range of that observed for commercial soda‐lime‐silica glass of good quality.

A possible explanation for the observed increase in density spread at higher temperatures (above 1325°) is offered on the basis of more rapid initial segregation during melting at higher temperature as inferred from the density‐spread data and from chemical analyses of the glass from the top and bottom portions of melts made at 1232° and 1454°C.

Loss in weight of the glass due to volatilization was determined at 1232° and at 1454°C. and was found to amount to less than 0.01% for a four‐hour melting period at both temperatures.

Moderate mixing, achieved by repeated cracking and remelting of the glass and by melting in a rotating tilted crucible, had a marked effect in lowering the density spread.

The data afforded by these experiments lend further emphasis to the view that convection currents in commercial tank operation are highly significant in improving the homogeneity of a soda‐lime‐silica glass.
STUDY OF GLAZE PENETRATION AND ITS EFFECT ON GLAZE FIT: I‐III*
Authors: Thomas Everett , Tuttle Milton A. , Miller Esther
Published: June 2006

Abstract

A method for determining glaze penetration was developed and the effect of glaze penetration on glaze fit studied. The effects of twenty‐four fluxes on penetration of a base glaze into semivitreous, hotel china, terra cotta, cordierite, pyrophyllite, wall tile, and steatite bodies were determined. The result shows that glaze penetration affects glaze fit and that penetration varies greatly, depending on glaze composition and the character of the body.
USE OF POTASSIUM DICHROMATE METHOD IN DETERMINING IRON CONTENT OF PICKLE ACIDS*
Authors: Porst Edward G.
Published: June 2006

Abstract

The metallic iron content of sulfuric acid pickle solutions has for many years been determined by the potassium permanganate method. Developments in the field of indicators have made possible the use of potassium dichromate. A description of the method and a discussion of results are given.
REACTION BETWEEN COPPER REVERBERATORY SLAG AND REFRACTORIES*
Authors: Kocatopcu Sahap S.
Published: June 2006

Abstract

Small slag cylinders placed on top of different refractory brick were heated at 1300° and 1400°C. Depth and width of reaction and diffusion zones were measured, and thin sections through the penetrations mere studied.
MOLYBDENUM IN ENAMELS: III, TYPICAL MOLYBDENUM ENAMELS*
Authors: Kautz Karl
Published: June 2006

Abstract

Compositions and characteristics of various types of enamels using the most successful mill additions in Parts I and II are reported. The enamels used in this paper are (1) clear enamels (regular) for ground or colored coats, (2) clear enamels (acid resisting) for colored coats, (3) high lead clear enamels maturing below 1000°F., (4) raw or partially fritted enamels for ground or colored coats, and (5) white antimony enamels for direct application to the metal base. Reported for the first time are some white enamels containing molybdenum in the frit, which adhere to sheet steel without additions of molybdenum compounds to the mill.
SOME CLAY‐WATER PROPERTIES OF CERTAIN CLAY MINERALS*
Authors: Grim R. E. , Cuthbert F. L.
Published: June 2006

Abstract

Computed values are given for the thickness of the water film adsorbed on the surfaces of the various clay minerals when clays composed of such minerals develop specific plastic characteristics. Based on such values, the following concept of clay‐water relationships is presented: The dominant factor determining the plastic properties of clays is the rigidity of the water held on the surfaces of the clay minerals, and the point of beginning of the transition of completely rigid water to liquid water is marked by great changes in such properties. Each type of clay mineral seems to have a characteristic ability to stabilize water, and the exchangeable ions also exert an influence. The reaction between water and kaolinite or halloysite may require considerable time so that there is frequently a time lag after mixing clays composed of such minerals before the plastic properties are fully developed.

Application of the foregoing concept in the fields of geology, ceramics, and soil mechanics are suggested.
RELATION OF METAL THICKNESS, ENAMEL THICKNESS, AND BOTTOM RADIUS TO IMPACT RESISTANCE OF PORCELAIN ENAMELED UTENSILS*
Authors: Petersen F. A. , Andrews A. I.
Published: June 2006

Abstract

Three series of standard two‐quart pudding pans of different metal thicknesses, coated with one, two, and three coats, respectively, of enamel were tested for impact resistance, using the Enameled Utensil Manufacturers' Council standard impact test. The impact resistance of the pans was increased with increase (1) in metal thickness of the pans, (2) of the enamel thickness, and (3) in the size of the bottom radius. The size of the chip formed on impact also increased with increase in enamel thickness.

The literature dealing with the fracture of glass and enamels is reviewed, and the factors influencing spontaneous chipping and chipping caused by bending and impact are discussed.
SPLITTING OF SOFT‐MUD BRICK*
Authors: Schurecht H. G. , McMahon J. F.
Published: June 2006

Abstract

A study was made of the cause and methods of preventing the splitting of Hudson River soft‐mud brick. The splitting occurred in the kiln and paralleled the 8‐ by 4‐in face of the brick and was found to be associated with black coring. Tests made on various portions of the brick showed that the black portions were more vitreous and had lower thermal expansions than the outer, more oxidized portions. On cooling, the stresses resulting from the difference in thermal expansion were such as to tend to split the brick Modification of brick mixes and method of setting are recommended to overcome black coring.
ABRASION OF GLASS AS RELATED TO COMPOSITION *
Authors: Scholes† S. R.
Published: June 2006

Abstract

The abradability of glass of different compositions was estimated by grinding on a steel plate with powdered quartz as an abrasive, determining the weight removed from the ends of glass'rods, reducing this to volume, and comparing with the volume removed from used silica rods by the same treatment. Silica (SiO2) and B2O2 are constituents contributing to resistance to abrasion, while soda, lime, and especially lead oxide produce high abradability. Abradabilities are expressed in numbers referred to silica glass as unity.