bluuebunny/crossref_metadata_2025 huggingface dataset:
THE USE OF FINELY MILLED ENAMEL SLIPS*
Authors: Porter F. R. , Holscher H. H.
Published: October 2006

In general, cover‐coat slips for sheet iron are milled to give a residue of from 4 to 9% on a 200‐mesh sieve. The opinion was formed that finer milling results in tearing because of results secured on the box‐type rather than the continuous furnace. However, cover‐coat slips milled from 12 to 0.2% on a 325‐mesh sieve are now in use in production on continuous furnaces with no increase in tearing over coarse grinding and with the following advantages: (1) higher opacity, (2) less wear on spray guns, (3) smoother finishes, (4) preferred by sprayers, (5) better suspension, and (6) lower firing temperatures.
THE SYSTEM Na2O‐B2O3 I Preparation of Crystalline B2O3 and Some of Its Physical Properties*
Authors: Cole Sandford s. , Taylor Nelscon w.
Published: October 2006

A method of forming crystalline B2O3 by vacuum dehydration of H3BO3 is described. The resulting product is crystalline and has a refractive index of 1.458, specific gravity of 1.805, and melting point of 294°C. Devitrification of the anhydrous B2O3 glass at 280°C has also been accomplished, and a refractive index of 1.458 has been obtained. The X‐ray pattern has been made. The structure is cubic, ao= 10.03 Å, 16 molecules B2O3 per unit cell.
THE SYSTEM R2O‐B2O3, II
Authors: Cole S. S. , Scholes S. R. , Amberg C. R.
Published: October 2006

The melting points and the optical and mineralogical properties of potassium metaborate, sodium metaborate, and hydrated sodium metaborate are reported. The hydrated sodium metaborate was produced by a wet method from sodium hydroxide and boric acid as well as by hydration of the fusion product. The sodium and potassium metaborates were formed by dry fusion of Na2CO3 or K2CO3 and H3BO3 and by dehydration of the hydrated form. The anhydrous metaborates formed hexagonal crystals and the hydrated salt is monoclinic. X‐ray diffraction data for Na2O.B2O3 are reported and the unit cell is calculated as ao= 6.85 Å, co= 10.95 Å, c/a = 1.60.
EFFECT OF MOISTURE UPON ELECTRICAL RESISTANCE OF EMBEDDING CEMENTS*
Authors: Melton R. L. , Brownell K. W. , Easter G. J.
Published: October 2006

For insulating electrical resistors from the casing of household appliances, etc., ceramic cements when properly applied are superior to other materials. If not sufficiently vitrified after application, however, they absorb moisture, thus tending to lower their resistance sufficiently to permit users of the appliances to experience electrical shocks. The necessary firing temperature varies widely with different cements. Some are satisfactory when cured by the heat of the embedded resistor alone while others are not. The hygroscopic properties are shown to be markedly increased by the presence in the cement of bentonite, borax, mica dust, or glass cullet. The borax also reduces the ultimate resistance objectionably at higher temperatures.

The apparatus used for testing is described in detail.
THE ANALYSIS OF FELDSPAR*
Authors: Knowles H. B. , Redmond J. c.
Published: October 2006

ASSTRACT

The methods commonly used for the chemical analysis of feldspar require an excessive amount of time, particularly if the analysis is to be used only for grading the material and where great accuracy is not essential. More rapid methods are described for determining alumina, calcium oxide, and the alkalis. In these, alumina is determined by precipitating with 8‐hydroxyquinoline in acid solution and then titrating an acid solution of the precipitate. Calcium oxide is determined by precipitating with oxalic acid without prior removal of aluminum and then titrating with standardized potassium permanganate. The alkalis are weighed as chlorides and potassium is determined by difference after sodium has been weighed as the triple acetate. Optional methods for attacking feldspar by acid instead of by fusion are described.
THE WATER‐SMOKING PERIOD AND ITS CONTROL*
Authors: Carruthers J. L.
Published: October 2006

The importance of the water‐smoking period, the work done, and the difficulties often encountered during this period in firing heavy masses are reviewed. The reasons for and the methods of preventing these difficulties are discussed. Maintenance of the dew‐point of the kiln gases several degrees below the temperature of the ware that the gases contact until all the ware is heated to 212°F is suggested as a method for obtaining desired kiln conditions and efficient firing. The dew‐point is controlled by rate of combustion and amount of excess air. A control system consisting of an aspiration psychrometer and a pyrometer and the method of using these instruments are described.
MICRO‐GAS ANALYSIS OF GAS TRAPPED IN VITREOUS ENAMELS ON ENAMELING IRON DURING FIRING*
Authors: Freeman S. E. , Meloche V. W.
Published: October 2006

A technique is described which is available for the analysis of trapped gases in vitreous enamels. The composition of gases trapped in a special enamel coat has been given.
THE CONVERSION OF QUARTZ INTO CRISTOBALITE BELOW 1000°C, AND SOME PROPERTIES OF THE CRISTOBALITE FORMED*
Authors: Cole Sandford s.
Published: October 2006

An investigation of the conversion of quartz into the higher temperature forms of silica was made in order to establish whether cristobalite or tridymite is first formed in the temperature range 850 to 1050deg;C. The results of over 800 determinations established the fact that sodium silicate promotes the conversion and is materially superior to other fluxes reported in the literature.

Cristobalite forms before tridymite in the conversion of quartz at 890 to 900°C. The rate of conversion is dependent upon time and temperature. The cristobalite in the temperature range studied was metastable and slowly converted to tridymite. The inversion of the low to the high form of cristobalite occurred at 250 to 260°C on heating. The refractive index was found to be in agreement with that for cristobalite formed at higher temperatures. The conversion is believed to be one of a solid‐liquid type, and a theory to explain the formation of cristobalite before tridymite is offered, based on the crystal lattice structure changes required to develop the two high‐temperature forms of silica from quartz.
PROPERTIES OF SOME OHIO RED‐FIRING CLAYS*
Authors: MacGee A. E. , White W. C. O. , Klinefelter T. A.
Published: October 2006

Properties of twenty‐six Ohio clays representative of those used in manufacturing heavy ware, such as brick and hollow‐ware, were studied from the raw clay to the finished laboratory product. Chemical and petrographic analyses were made. In the raw and plastic states data were obtained on the tempering water, the amount of load necessary to extrude the clay through a die, the base‐exchange capacity, and the particle‐size distribution as evidenced by sieve analysis and the water‐absorption method. In the dry state the minimum drying time, the shrinkage, porosity, apparent specific gravity, dry transverse strength, impact strength, and modulus of elasticity were determined. In the process of heating the clays to 1000°C, observations were made as to the kind and rate of evolution of the gases given off, the endothermic and exothermic reactions, and the expansion characteristics. The softening points of the clays were determined and, after heating to different temperatures, data on shrinkage, absorption, and transverse strength were taken.
PROPERTIES OF SOME AMERICAN KAOLINS AND A COMPARISON WITH ENGLISH CHINA CLAYS*
Authors: Klinefelter T. A. , Meyer W. W.
Published: October 2006

Nine American kaolins were studied. Chemical analyses were made and equivalent mineral compositions were calculated with the aid of petrographic examinations. Pyrometric cone equivalents, deflocculating characteristics, soluble‐salt contents, percentages of material composed of particles less than 0.6 micron in diameter, and base‐exchange capacities at pH7 were determined. Transverse strengths of dried and variously heat‐treated bars, made from mixtures of the clays with equal parts of potters' flint and shrinkages and apparent porosities of dried and progressively heat‐treated allclay specimens, were determined. Specimens of the dried and heated clays were examined for relative color, and linear thermal expansions of specimens heated to various temperatures were determined. The nine clays were divided into three groups and their properties compared with those of fifteen English china clays previously studied. Simulation of essential properties of the English china clays was accomplished in supplementary experiments by adding fluxes to American kaolins or kaolin blends.
FORSTERITE AND OTHER MAGNESIUM SILICATES AS REFRACTORIES*
Authors: Birch Raymond E. , Harvey Fred A.
Published: October 2006

In a survey of magnesium silicates for use as refractories, experimental studies with talc, serpentine, and olivine, and also with mixtures of these minerals and magnesia (MgO) are reported. Since forsterite (2MgO°SiO2) is the only magnesium silicate which has a stable existence above 1562°C, the development of a commercial magnesium silicate refractory required that the ultimate product should be mainly forsterite. Such a refractory was developed by enriching a low iron magnesian olivine with MgO. The magnesia served to convert certain accessory minerals found in the olivine rocks, including the hydrated minerals (talc and serpentine), to forsterite. Talc and serpentine are so universally present in olivine that, in the absence of the magnesia treatment, they provide a low melting bond which would cause the refractory to fail at relatively low temperatures under load and to exhibit other unsatisfactory properties. On the other hand, the forsterite refractory withstood an exceptionally high temperature before failure under load.

The general characteristics of the refractory are discussed. The data include refractoriness, strength hot and cold, volume stability when reheated, spalling, thermal expansion, chemical behavior, resistance to various slags, thermal conductivity, etc.
THE EFFECT OF REPEATED FIRING UPON THE SPECIFIC GRAVITY AND MICROSTRUCTURE OF SOME ALUMINUM‐SILICATE MINERALS*
Authors: Riddle Frank Harwood , Peck Albert B.
Published: October 2006

Repeated firing of several aluminum‐silicate minerals to the same temperatures show that the specific gravities of the fired products do not drop at the same rate. Petrographic‐microscopic examinations show that this is due to different rates of dissociation in the minerals. While these rates of reaction or dissociation can not be measured accurately, some idea of the relative rates can be obtained by comparison of the sizes of completely dissociated grains of the minerals or of the widths of the borders of the dissociation products formed around the grains. Furthermore, the effect of repeated firing upon the increase in size of mullite crystals formed when the minerals dissociate gives evidence concerning the rate of growth or probable refractoriness of the minerals. These are described in some detail and close correlation between them and the specific gravity changes are pointed out.
A STUDY OF SOME CERAMIC BODIES CONTAINING TALC*
Authors: Fallon Frank P.
Published: October 2006

Fluxing agents used in most steatite bodies contain alkalis which lower the electrical resistivity of these insulators. Attempts were made to obtain a vitreous steatite composition by additions of oxides containing no alkalis. The effect of grain size, liquids, and varying pressures was determined to obtain the best mixture which would produce the lowest absorption when fired to cone 14, and to this mixture the various oxides were added. The absorption and shrinkages were obtained after firing to cones 13 and 14.
NOTES ON HIGH SPECIFIC GRAVITY SLIPS*
Authors: Dacer P. W.
Published: October 2006

A discussion is given of the problem of obtaining the maximum specific gravity of a given slip at a specified viscosity.
EFFECT OF FURNACE ATMOSPHERE AND PARTIAL VACUUM UPON THE VITRIFICATION OF A HIGH MULLITE PORCELAIN*
Authors: Hossenlopp A. M. , Russell R.
Published: October 2006

A high mullite porcelain body was fired in various atmospheres and in vacuum. O2, CO2, and N2 atmospheres and vacuum were used separately for the firing, preceded by an oxidizing atmosphere up to 1000°C. The effect upon density and vitrification temperature and range was determined. An oxidizing atmosphere in all stages of firing is advantageous in obtaining high density. Firing in vacuum lowers the vitrification temperature 100°C and increases the vitrification range 20°C.
INVESTIGATION OF GLASSHOUSE SUPERSTRUCTURE MATERIALS*
Authors: Fabianic W. L.
Published: October 2006

A practical investigation was conducted on the selection of those refractories most suitable for use in glass‐furnace port jambs, port sills, port floors, baffles, port‐nozzle side walls, port side walls proper, and top checker courses. These refractories are exposed to the destroying action of a viscous high‐temperature basic slag and batch dust of a given composition. Over one hundred various brands of brick were tested, ranging in composition from a first‐grade fire brick to super‐refractories of the 80% alumina class. The mechanical, chemical, physical, and mineralogical properties of these brick were studied. The results of the test determinations were checked by making actual service installations in operating furnaces. The performance of the refractories in these installations after ten months of service verified the test results to a remarkable degree. The mineralogical relationship of the minerals in the refractory as received was found to be of more importance than chemical or physical properties. A tentative method of determining the suitability of a brick for actual service by combining petrographic inspection with physical properties is suggested.
THE TIME FACTOR IN THE TESTING OF GLASSWARE*
Authors: Preston F. W.
Published: October 2006

A preliminary report on the effect of the time element on the apparent strength of glass is given. Tests have been run on bottle glass from three seconds to 30 minutes duration and on polished plate and drawn window glass (in the form of laths) from five seconds to several hours.
MECHANICS OF ENAMEL SUSPENSION, II*
Authors: King R. M.
Published: October 2006

It is shown that it is possible to reveal reasonably small differences in the behavior of the various glasses when electrodialyzed. The results of electrodialysis agree fairly well with the tests and general knowledge of acid resistance.
MORTARS SUITABLE FROM THE STANDPOINT OF WATER‐TIGHTNESS IN UNIT MASONRY*
Authors: Palmer L. A.
Published: October 2006

This paper deals with results obtained in the leaky masonry study at the National Bureau of Standards. Possible improvements in test procedures in future investigations are indicated. The relative importance is shown of mortar properties on the one hand and brick properties on the other as they are concerned either with causing or preventing leaky masonry.
THE INFLUENCE OF SODIUM ALUMINATE IN A FIRECLAY SEWER‐PIPE BODY*
Authors: Carter W. K. , Duncombe Geo. H. , Hillyer E. E. , King R. M.
Published: October 2006

A laboratory study of the effect of sodium aluminate on the fired properties of a fire clay used in sewer pipe is discussed, especially with respect to the original kiln strength and strength permanency. The results of commercial applications of sodium‐aluminate additions in sewer‐pipe plants are given.
TALC IN WHITEWARE BODIES OF THE WALL‐TILE TYPE*
Authors: Geller R. F. , Creamer A. S.
Published: October 2006

Effects of MgO and of CaO, introduced as a lime‐free talc and as a lime‐bearing “tremolite” talc, in whiteware heated at four temperatures were investigated. The results indicate that (1) in earthenware bodies, 40% or less of talc may be expected to increase porosity slightly and materially decrease shrinkage, (2) thermal expansion may be greatly affected by small variations in the amount of talc used, the temperature of heating, and the percentage of CaO, and (3) talc has a beneficial effect on resistance to moisture crazing.
X‐RAY DIFFRACTION STUDY OF THE STRUCTURE OF SODA‐SILICA GLASS*
Authors: Warren B. E. , Loring A. D.
Published: October 2006

X‐ray diffraction patterns of soda‐silica glass have been made for seven different compositions varying from O to 46% Na2O. For small soda content, the patterns show a single strong peak at sinθ/λ= 0.12; with increasing soda content this peak diminishes in intensity, while at the same time a new peak at sinθ/λ= 0.18 gradually becomes the more pronounced. There is no abrupt change in the patterns. A random network picture of the glass is developed, and upon this basis X‐ray intensity curves can be calculated in good agreement with the experimental curves. Each silicon is tetra‐hedrally surrounded by four oxygens. Part of the oxygens are shared between two silicons; the others are bonded to only one silicon. The double‐bonded oxygens build up a continuous silicon‐oxygen framework. The sodium atoms are located at random in the various holes in this framework. There is no evidence for the existence of compounds in the range of composition studied.
TEST DATA ON STIFF‐MUD REFRACTORIES MADE FROM GEORGIA SEDIMENTARY KAOLINS UTILIZING VOID CONTROL*
Authors: Vaughan W. Harry
Published: October 2006

A discussion is given of the pyrophysical characteristics of different types of Georgia sedimentary kaolins suitable for refractories. Working and drying character, shrinkage, absorption, fired crushing strength, spalling resistance, pyrometric cone equivalent, and load‐bearing properties at high temperatures are given for some bodies made of semihard and hard sedimentary kaolins.
THE NATURE OF THE GLASS PHASE IN HEATED CLAY MATERIALS* I. COMMON CLAYS†
Authors: Shelton G. R.
Published: October 2006

The progress of fusion in an alluvial clay, a glacial clay, and a shale, when heated at various temperatures, was determined with the aid of the petrographic microscope. Thin sections and powdered samples obtained from the heated clay specimens were used in these tests. The relationships between the amounts and kinds of glasses in the specimens and the properties of the glasses were determined. Shrinkage and porosity of the specimens were found to depend not only on the temperature at which glass formation started but also on that at which the glass became sufficiently fluid to allow contraction of the specimen to take place. The colors of the heated clay specimens were governed largely by the crystallization of the glass bonds. Solution of the crystals formed by devitrification also profoundly affected the colors of the specimens. The increase in intensity of the red color of the specimens of alluvial clay and shale was directly related to the increase in the number of red crystals produced in the glass phases. The loss of red color by these specimens heated at very high temperatures in an oxidizing atmosphere and also at lower temperatures in a reducing atmosphere was caused by solution of the red crystals. The glassy bond in the specimens of glacial clay differed in composition from that in the alluvial clay and shale, which prevented the development of a red color of the specimens. A black glass, formed on solution of the red crystals, produced a dark gray color in the overheated specimens and in those heated in a reducing atmosphere. The growth of fine‐grained green crystals in the glacial clay specimens was a factor in neutralizing the small amount of red color originally in these test pieces.
A STUDY OF FURNACE ATMOSPHERES AND TEMPERATURE GRADIENTS AND THEIR EFFECT ON PORCELAIN ENAMELING*
Authors: Ebright H. E. , Mcintyre G. H. , Irwin J. T.
Published: October 2006

The factors affecting variations in furnace atmospheres and temperature gradients are discussed. Analytical methods and technique used in determining temperature gradients are given. Typical furnace atmosphere compositions are reported together with their effects on enamel‐ware quality and production. Several specific cases of shop troubles which are traced back to the firing furnace and the corrections applied are discussed in detail.
THE FINENESS DISTRIBUTION OF VITREOUS ENAMEL AS AFFECTED BY VARIATIONS IN GRINDING*
Authors: Poste E. P.
Published: October 2006

The results of an experimental study of the effects of variations in some of the conditions of grinding vitreous enamels on the distribution of particle size are given. These are followed by observations on the distribution of particle size in commercial batches of various enamels.
INVESTIGATION OF SOME PHYSICAL FACTORS AFFECTING THE DRAINING QUALITIES OF GROUND‐COAT ENAMELS*
Authors: Noble W. N. , Lindsey G. S.
Published: October 2006

The temperature of milling of sheet‐iron ground‐coat slip, rapid cooling versus slow cooling, and the temperature of the slip for draining are shown to affect draining qualities. The amount of water used for milling also influences the draining properties. No great differences, except better retention of set under the former condition, occur from milling ground‐coat frit separately and blending after milling compared to blending before milling.
MECHANICS OF ENAMEL ADHERENCE, XI
Authors: Housley W. L. , King R. M.
Published: October 2006

Some white oxides have been found which give a dendritic formation when incorporated in enamels to be applied directly to steel. An X‐ray study of these formations has been made.
KINETICS OF SOLID‐PHASE REACTIONS OF CERTAIN CARBONATES WITH MULLITE, SILICA, AND ALUMINA*
Authors: Pole Gordon R. , Taylor Nelson W.
Published: October 2006

Quantitative measurements of the rates at several temperatures of reactions between carefully sized solids have been made by determining the amount of CO2 evolved as a function of the time. While the absolute rate is a function of grain size and other factors, the temperature coefficient gives a constant characteristic of the chemical system involved. The reaction product is found to lessen the speed of reaction in accordance with the relation, dyjdt=k/y, where y is the thickness of the layer of reaction product. Under comparable conditions, sodium carbonate attacks mullite most easily, with less attack on quartz, and least on corundum. The activity of calcium carbonate on mullite, quartz, and corundum is considerably less marked. Applications to glass melting and to corrosion of refractories by alkali or alkali‐earth dusts are discussed. A table of values of the function, , for positive integral value of x form 1 to 100 is included.
THE DETERMINATION OF ALKALIS IN SILICATES WITH SPECIAL REFERENCE TO HIGH‐ALUMINA REFRACTORIES*
Authors: Read Edgar B.
Published: October 2006

This investigation pertains to the detailed study of two methods used to determine alkalis in silicates. The work was prompted through the difficulty of obtaining complete decomposition of high‐alumina refractory materials by the usual procedure.

It was found that high‐alumina materials may be decomposed by the J. Lawrence Smith procedure with a single fusion, provided this is conducted at approximately 1200°C.

The second procedure has to do with the decomposition of the sample with a mixture of nitric, sulfuric, and hydrofluoric acids. In this method, magnesia is eliminated by precipitation with 8‐hydroxyquinoline and the alkalis are weighed as sulfates. Experimental data are given pertaining to these procedures when used for the analysis of several types of materials.
SCREEN ANALYSES FOR PLANT CONTROL*
Authors: Rugh Edgar W.
Published: October 2006

A practical method of making screen analyses and of expressing the results is described. By the use of a second accumulation the analyses may be expressed numerically. Plotting the second accumulation data on a functional scale will allow checking the analyses for satisfactory grain‐size distribution.
Viscosity and Electrical Resistivity and their Bearing on the Nature of Glass*
Authors: Taylor Nelson W.
Published: October 2006

Abstract

The mechanisms of viscous flow and of electrolytic conduction in liquids have been examined to show the significance of the activation energy which is evaluated from the temperature coefficients of viscosity and electrical resistivity. It is shown that the high numerical values characteristic of silicate glasses arise from the ionic character of the liquid, the small coordination number (4) for silicon, and the high electric charge on the ions (Si, 4; 0,2; etc.). Below the softening range, a glass is not necessarily stabilized (i.e., in equilibrium with respect to molecular association or dissociation processes) and its properties depend on its history, mechanical, thermal, etc. In stabilized glasses, the activation energies for viscosity and electric resistivity rise continually with falling temperatures, showing no maximum, in contrast to the views of Preston and Seddon.

The oxygen, to silicon ratio has a dominating rôle in the structure of silicate crystals, as shown by W. L. Bragg. Similar concepts are applied to glass, and it is shown that the Preston‐Seddon proposal of definite compounds in soda‐silica glasses may be replaced by an alternate explanation.

The quantity, β, in the equation, η=arβ, which relates viscosity to resistivity, has a value of 4 to 6 for certain soda‐containing glasses. The suggestion is made that viscous shear requires the breaking of four to six times as many sodium‐oxygen bonds as does electrical conduction.

Finally, an internal energy‐temperature curve, based on specific‐heat data for fused silica, has been constructed. The curve shows a. steady rise with increasing temperature. It is typical of several glasses.
DIRECT DETERMINATION OF SODIUM OXIDE IN FELDSPAR*
Authors: Koenig E. W.
Published: October 2006

Abstract

A method for the direct determination of sodium oxide in feldspars is described. Data derived from an investigation conducted to determine the optimum conditions for the accurate estimation of this alkali metal by the prescribed procedure are tabulated and the results are discussed. The application of the method to the analysis of other related silicates is mentioned briefly.
USE OF BROMATE IN VOLUMETRIC ANALYSIS: VII, POTENTIOMETRIC TITRATION OF HYDROXyQUINOLINE *
Authors: Smith G. Frederick , May R. L.
Published: October 2006

Abstract

The potentiometric titration of 8‐hydrOxyquinoline and the metallic inner complexes, i.e., magnesium oxyquinolate, is described, using direct titration with a standard bromate solution of the hydrochloric acid solution of the hydroxyquinoline or its derivatives with particular reference to magnesium oxyquinolate. Potentiometric procedures for direct determination have been developed using the electrode system, platinum‐nickel. This procedure involves the use of the monometallic, platinum‐platinum electrode pair and the electron beam sectrometer as the recording instrument, which has a distinct advantage of speed and equal accuracy over previous electrometric titrations. A series of experimental analyses has been carried out both on the hydroxyquinoline and its magnesium salt. The procedure is well adapted to routine plant control analyses, and a separation of calcium prior to the determination of magnesium is not required.
CRITICAL STUDY OF THE DIFFERENTIAL THERMAL METHOD FOR THE IDENTIFICATION OF THE CLAY MINERALS*
Authors: Norton F. H.
Published: October 2006

Abstract

An apparatus is described for studying clay minerals by the differential thermal method, which has some advantages over previous types of apparatus. Thermal curves are given for many of the pure clay minerals for use as standards of identification. The use of this method quantitatively for the determination of the relative amounts of clay minerals in a natural clay is discussed, and examples are given for a number of high alumina clays.
EQUATIONS AND QUADRANT CHARTS FOR DETERMINING HEAT BALANCES OF KILNS USING SOLID OR LIQUID FUELS*
Authors: Skinner Kenneth G.
Published: October 2006

Abstract

Equations are derived for determining heat balances of kilns using solid and liquid fuels, and quadrant charts are given for graphic solutions. Charts and equations are also given for determining the weight of air supplied, theoretical weight of air required for combustion, percentage of excess air, volume of moist air, weight of refuse, percentage of hydrogen and oxygen from the moisture‐ and ash‐free basis to the as‐fired basis, and heat content of fuel oils of different specific gravities.
SPALLING OF SILICA BRICK DURING HEATING AND COOLING OF FURNACES*
Authors: Mckinley J. M. , Phelps S. M.
Published: October 2006

Abstract

A study of the sapling of silica brick in service has shown that a cobblestone shape of fracture usually occurs. Inasmuch as this fracture was not secured in laboratory tests, a study was made of the influence of the various heating and cooling treatments to bring about this type of fracture. Several procedures which gave this result are recorded.
EFFECT OF SODIUM ALUMINATE ON THE THERMAL EXPANSION OF REFRACTORY CLAY BODIES*
Authors: Morgan W. R.
Published: October 2006

Abstract

Additions of 2% sodium aluminates to highly siliceous clay‐flint bodies fired at cones 13 to 14 appreciably decreased but did not eliminate the cristobalite expansion. A second firing at the same temperature increased the cristobalite expansion, compared with that produced in the first firing, but the expansion in both cases was less than that of the body without the addition of sodium aluminates. A similar addition made to Missouri semiflint clay increased the cristobalite expansion after one firing but decreased it after a second firing, compared, in both cases, with the expansion of the body to which no sodium aluminate had been added.
ZINC‐VAPOR GLAZING OF CLAYS: I*
Authors: Lampman C. Major , Schurecht H. G.
Published: October 2006

Abstract

A study was made of the influence of the iron‐oxide and alkali contents and absorptions of clay bodies on their ability to take a zinc‐green vapor glaze. Although greens may be obtained on bodies with a wide range of compositions and with absorptions up to 8.4% under exacting conditions, the range of bodies which take a green glaze under less favorable circumstances is comparatively small. The probability of obtaining good greens was greatest with those bodies whose absorptions were below 2% and which contained 8 to 18% iron oxide and more than 6% alkalis. Firing to higher temperature and cooling rapidly improved the tendency to produce greens. Desirable tans, browns, brick reds, and grays were obtained by firing to low temperatures and cooling slowly.
INFLUENCE OF FLUIDITY, HYDRODYNAMIC CHARACTERISTICS, AND SOLVENT ACTION OF SLAG ON THE DESTRUCTION OF REFRACTORIES AT HIGH TEMPERATURE*
Authors: Endell K. , Fehling R. , Kley R.
Published: October 2006

Abstract

Two methods for determining viscosity in the range 0.1 to 105 c.g.s. units (poises) at temperatures up to 1650°C are described, and some results on slags and glasses are given. Attack on any given refractory at a given temperature increases markedly with the fluidity of the slag. Researches with hydrodynamic models show that the velocity of flow and film thickness depends more on the viscosity of the slag than on the angle of inclination of the path of flow. A new interpretation of the solvent action of slags on refractoriness, together with thermodynamic considerations and measurements of viscosity, permits a general mathematical treatment of the complicated changes occurring during slagging. Slag attack may be effectively lessened by choosing a refractory of low solubility and by cooling the wall to a temperature of less than 50°C above the melting point of the slag.
REACTIONS OF SLAG WITH REFRACTORIES: I, SURFACE REACTIONS*
Authors: Schurecht H. G.
Published: October 2006

Abstract

Several new methods of studying the surface reactions of slags, glass, and Portland cement clinker with refractories were compared. The penetration of the slag into refractories and the slump of slag spheres disclosed considerable information regarding surface reactions which other tests failed to show. For the more refractory slags, such as Portland cement clinker, acid open‐hearth, copper reverberatory, and basic open‐hearth slags, these reactions were governed largely by the relative acidity or basicity of the slags and the refractories, i.e., basic slags showed the greatest reaction with acid refractories and vice versa. For the more fusible materials, such as glass, lead blastfurnace slag, and coal ash, the relative acidity or basicity of the slag and refractory is less important. With these slags, the low porosity of the refractory, which prevents the penetration of the very fluid slags, probably is more important.
SOLUBILITY OF COLORED GLAZES IN ORGANIC ACIDS*
Authors: Geller R. F. , Creamer A. S.
Published: October 2006

Abstract

The purpose of this study was to determine primarily which, if any, of the glazes tested constituted a health hazard because of lead or other toxic oxides which might be dissolved from them; and, secondarily, to develop suitable test procedures for future control work.

A conference of representatives of the U. S. Potters Association, the Food and Drug Administration of the Department of Agriculture, and the National Bureau of Standards was held, and a series of accelerated and simulative service tests was outlined. These tests were made on specimens from six cooperating manufacturers.

It was shown that the lead extracted by pouring either hot, distilled vinegar (5% acetic acid) or an 0.5% solution of citric acid in a cup and leaving it to cool in contact with the glaze for 1/2 hr. would be as much, or more, than the lead normally extracted by jams and fruit juices. With the same or a similar test procedure, a citric‐acid solution of 10% strength may be required to indicate how much lead might be taken up by lemonade or vinegar.

The results also indicate that glazes of one color only, among those tested, constitute a probable health hazard. Two other glazes from one manufacturer, however, were found to be marginal, and a third may cause trouble if indicated corrective measures, such as a preliminary acid wash, should be neglected by the manufacturer.
WORKABILITY OF CLAYS*
Authors: Graham Robert P. , Sullivan John D.
Published: October 2006

Abstract

Stress‐strain relationships were established in a torsion machine on 6 clays with varying water content in the workable stiff‐mud range. Torsion tests gave the following measurements: (1) yield point, (2) maximum torque, (3) angle of deformation at maximum torque, and (4) angle of deformation at ultimate failure. Lawrence clay exhibited the highest angle at maximum torque and angle at ultimate failure of the plastic clays studied. Georgia kaolin had a low yield point, maximum torque, and angle at maximum torque. Workability in the stiff‐mud range is not necessarily a measure of workability of the same bodies with different moisture contents.
A UNIQUE CLAY FROM THE GOOSE LAKE, ILLINOIS, AREA*
Authors: Grim R. E. , Bradley W. F.
Published: October 2006

Abstract

A deposit of nonbentonitic clay has been found in the Goose Lake area of Illinois. The clay has unique properties and composition, and it is marketed under the trade name “Grundite.” Its chief constituent was first thought to be beidellite, but further detailed microscopic, X‐ray, and chemical studies have shown that it is composed of a distinctive mica‐clay mineral of the illite group. The clay possesses properties of plasticity, strength, and gel formation which have caused wide usage, in a variety of fields. The occurrence, constitution, and properties are discussed.
THE SEMIDIRECT DETERMINATION OF POTASSIUM OXIDE IN FELDSPARS*
Authors: Koenig E. W.
Published: October 2006

Abstract

A method for the evaluation of potassium oxide in feldspars, without the necessity of first removing the constituents which usually interfere with this determination, is described. The procedure is based upon a decomposition with HF‐HClO4, followed by the separation of potassium as the double salt ((K, Na)3Co(NO2)6·xH2O), with a final conversion to KClO4 in the usual manner. Analytical data are given to indicate the relative precision and accuracy of the method compared with procedures in use at the present time. The application of the proposed method to the analyses of other silicates is mentioned briefly.
EFFECT OF BORON OXIDE, PHOSPHOROUS PENTOXIDE, AND FERRIC OXIDE ON THE THERMAL EXPANSION OF A FLORIDA KAOLIN‐QUARTZ MIXTURE*
Authors: Thompson C. L. , Parmelee C. W.
Published: October 2006

Abstract

The effect of small additions of B2O3, P2O5 (as aluminum phosphate), and Fe2O3 on the thermal expansion of a body composed of 40% quartz and 60% Florida kaolin after single and repeated firings was studied. The boron oxide gave marked reduction in the thermal expansion of the mixture after repeated firings (ranging up to cone 16) in that portion of the specimen from which it had not been volatilized. In all other cases, it had little effect. The iron oxide caused small but distinct reductions in the thermal expansion of the mixture. The effect of the phosphorous pentoxide was only slight.
MECHANISM OF MILL‐ADDED OPACITY IN PORCELAIN ENAMELS*
Authors: Andrews Andrew I. , King Burnham W.
Published: October 2006

Abstract

The microscopic appearance of sheet‐iron, white cover enamels indicates that mill‐added opacifiers function principally as layers between the frit particles and do not diffuse well into the enamel. This explains the reasons why (1) mill‐added opacifiers do not continue to increase reflectance when added in large quantities, (2) increased fineness of milling aids reflectance, (3) extreme fineness of opacifiers is necessary, and (4) transparent glassy frits appear mottled with mill‐added opacifiers. From these observations it is evident that increased reflectance of enamels originates in the frit or is brought about either by finer milling or by better diffusion of mill‐added opacifiers.
SAG‐RESISTING PROPERTIES OF ENAMELING IRON*
Authors: Porter Frank R.
Published: October 2006

Abstract

A method is given to determine the sag‐resisting properties and the effect of the composition of enameling iron, its gauge, and the temperature on sag values. A theoretical consideration of the deflection of beams is also given. Two types of test strips, one 12 inches long supported near the ends and the other 5.55 inches long and supported at one end, were used. Both types have merit, but the 12‐inch strip seemed to give better results. The composition of the iron seemed to affect the sag values, e.g., mild steel, with more carbon and manganese, showed higher sag values than enameling iron. The heavier gauge values decreased the amount of sag. Sag values increased with increase of temperature, particularly above 1500°F.
FINAL PROGRESS REPORT ON PLASTIC PRIMARY NORTH CAROLINA KAOLINS, METHODS OF THEIR USE, DEVELOPMENT OF VITREOUS BODIES, AND EXPERIMENTS WITH A CONTINUOUS, HIGH‐TEMPERATURE, ELECTRIC TUNNEL KILN: PARTS I–VII*
Authors: Gould R. E. , Hbdquist A. J.
Published: October 2006

Abstract

Data are presented covering twelve months of tests on the commercially refined plastic North Carolina kaolins. Both days had constant physical properties. Chemical analyses and ceramic laboratory tests show that the commercially refined kaolins are more plastic, stronger, and better than those which were refined in the laboratory and previously recorded. Treatment in a vacuum pug mill was necessary to develop the maximum strength and plasticity of the kaolins. The modulus of rupture, both dry and fired, is quite high for a primary kaolin, and the fired color is good.
II, FURTHER DEVELOPMENT AND TESTING OF A TRUE PORCELAIN AND VITREOUS CHINA DINNERWARE BODY USING NORTH CAROLINA KAOLIN AS THE CHIEF PLASTIC CONSTITUENT
Authors: Gould R. E. , Hedquist A. J.
Published: October 2006

Abstract

A body with the composition of clay substance 41, feldspar 16.6, quartz 40.4, and dolomite 2 was tested on a pilot‐plant scale for twelve months and results were recorded. The body was varied in the two different types of commercially refined North Carolina kaolin, which formed the main plastic ingredient, and in the pegmatites, which were substituted for the feldspar and part of the quartz. Ball clay was not used because it is harmful to translucency; 12.7% Florida kaolin was added to attain the necessary plasticity and dry strength.

Special emphasis was placed on the working properties to determine whether this body could be worked as fast and as safely as semivitreous or hotel china bodies. It was possible to hold the average dry strength constant to 350 lb. per sq. in., and this modulus of rupture seems to be sufficient for mass‐production methods. The plasticity was greatly increased by vacuum pug‐mill treatment and by aging two or three days.

One N, C. kaolin may be substituted for the other if proper attention is paid to the chemical analyses and to the adjustment of body shrinkage and absorption requirements. The fired color is white under reducing conditions and light ivory under oxidizing conditions. The translucency is sufficient to enable the ware to compete easily with that imported from Europe.
Ill, NOTES ON CASTING ALL‐KAOLIN BODIES
Authors: Hedquist A. J. , Wilson E. , Gould R. E.
Published: October 2006

Abstract

The bodies recorded in Part II were tested to see whether casting could be done quickly and easily and kept under close control. Two deflocculants were used which previously had been found best for bodies made from all‐American kaolin, viz., sodium gallate and the commercially prepared No. 2 clay deflocculant. Both dispersing agents were successful, with the No. 2 clay deflocculant slightly better.

One hundred and twenty‐five 1/4‐ton batches were processed. It was possible to control the casting properties within extremely close limits if the viscosity, specific gravity, and temperature were held at specified values thought to be easily attainable. It was important to have the clay properly prepared before making it into casting slip, and it was especially necessary to have it pugged from the filter press, aged 2 or 3 days, and repugged under vacuum. The casting appeared to be much better than that of the average semivitreous or hotel china bodies commonly found in production. With these dispersing agents, the mold life was much longer than with sodium carbonate and sodium silicate.
IV, NOTES ON LABORATORY EXPERIMENTS IN THE PRODUCTION OF FLATWARE
Authors: Gould R. E. , Fichter G. W.
Published: October 2006

Abstract

Further experiments are reported on the bisque firing of plates with mechanical braces to hold them straight. By bracing the rim and bottom of the plate, the force exerted is more than the internal strains in the plate tending toward deformation, and the plates so fired come to the desired degree of straightness, provided the dimensions are correct. The permissible variations in the dimensions are not more than = 0.001 inch. This dimension is attained by trimming the feet and rings in the leather‐hard state to the prescribed measurements. A new method of making flatware cheaply by casting the plate and overcasting the foot is described. This method is successful if the mechanical bracing in the firing process is used.
OXIDE FILM BETWEEN FIRED GROUND‐COAT ENAMELS AND IRON*
Authors: Kautz Karl
Published: October 2006

Abstract

A study of the oxide film between enamel and iron was made by sticking together specimens of fired ground coat in a furnace and tearing them apart when cold so that the oxide film was separated from one of the iron surfaces. The chemical behavior of this film indicates that FeO is present. Microscopic examinations reveal a typical iron‐scale structure. Chemical and X‐ray analyses show that the film is composed principally of Fe, FeO, and Fe3O4.
OBSERVATIONS ON THE FUNCTION OF ADHERENCE‐PROMOTING OXIDES IN GROUND‐COAT ENAMELS*
Authors: Kautz Karl
Published: October 2006

Abstract

Five enamels were smelted which contained (a) no adherence‐promoting oxides, (b) 0.5% Co3O4, (c) 0.5% NiO, (d) 1.0% MnO2, and (e) all three oxides. A study was made of the effect of these oxides in the enamel upon (1) the adherence to sheet iron, (2) the iron oxides formed between the enamel and iron base, and (3) the ability of the enamel to carry or transmit oxygen from the air to the iron base. The results obtained show that cobalt oxide promotes adherence, allows heavy films of iron oxide to form at the surface of the iron, and accelerates penetration of aerial oxygen through the molten enamel layer. Nickel oxide behaves like cobalt oxide, but it is much weaker. The results show that manganese oxide does not promote adherence, allows no iron‐oxide films to form, and has a slight effect only upon the penetration of aerial oxygen through the molten enamel layer.
EFFECT OF FURNACE GASES ON PHYSICAL PROPERTIES OF WET‐PROCESS CAST‐IRON ENAMELS*
Authors: Spencer‐Strong G. H.
Published: October 2006

Abstract

Lead‐bearing and leadless cast‐iron enamels, applied directly on the iron, and leadless enamels, applied over a ground coat, were fired in normal, low oxygen‐high nitrogen, high carbon dioxide, and high water‐vapor atmospheres, and the effect upon the surface and physical properties in relation to impact and thermal resistance was determined. The enamels in some cases were applied over graphited castings, fired in the several atmospheres, and tested. The behavior of different types of enamel fired in various atmospheres differs, the leadless enamel applied over ground coat showing the least effect. High water‐vapor content appears generally to be more deleterious than the other atmospheric conditions.
THE SERIES IRON OXIDES‐SILICA*
Authors: Crook Welton J.
Published: October 2006

Abstract

A review is presented of the previous work by the writer on the general series FeO‐Fe2Os‐SiO2‐CaO (MgO) as related to steelmaking slags, in which 12 quasi‐quaternary mineral systems are formed. A “plane of partition” of the iron oxides (FeO and Fe2O3) is also shown to exist. A method is explained by which, having a partial analysis of a slag, the position of the slag in the representative tetrahedron may be found and the series of minerals formed may be determined.

The present paper is a study of the system iron oxides‐silica under conditions of formation with and without the presence of metallic iron. In the former case, two distinct eutectiferous series are formed, viz., (a) wustite‐fayalite and (b) fayalite‐tridy‐mite. The reducing power of metallic iron is so great that substantially the same proportions of FeO and Fe2O3 are obtained when melting is conducted either under strongly oxidizing conditions or in a neutral atmosphere. A “eutectoid” between magnetite and tridymite contains equal molecular proportions of SiO2 and Fe3O4. When iron oxide and silica are heated at 1600°C or higher in siliceous crucibles, the resulting melts consist essentially of tridymite and magnetite, forming an entirely different series than that obtained by melting in the presence of metallic iron. In connection with both series of melts, ferric oxide exhibits a much greater affinity for ferrous oxide than for silica.
A CRITICAL EXAMINATION OF THE LOAD TEST FOR REFRACTORIES*
Authors: Norton F. H.
Published: October 2006

Abstract

Methods and equipment are described for making long‐time load tests on refractories similar to creep tests for metals. A uniform flow rate is not established until approximately 100 hours have elapsed and shorter tests give load values considerably lower than can be used safely in design work. It is suggested that a long test of this type would be a more satisfactory standard than the short test now used.
OBSERVATIONS ON THE SLAGGING OF SOME GLASS FURNACE CHECKERS*
Authors: Fabianic W. L.
Published: October 2006

Abstract

Two brands of super‐duty fireclay brick with similar physical and chemical properties were selected. These two brands were put into opposite regenerators of the same commercial furnace melting a soda‐lime glass. One brand failed before the furnace compaign was completed and the other did not. Investigation showed that one of the main differences between the two brands was the amount of microscopically visible mullite crystals present.