bluuebunny/crossref_metadata_2025 huggingface dataset:
THE THERMAL CONDUCTIVITY OF SOME REFRACTORIES1
Authors: Norton F. H.
Published: June 2006

The problem of measuring the thermal conductivity of materials up to high temperatures has been studied, especially in regard to the sources of error. This investigation has shown that many of the previous determinations of thermal conductivity may have had little precision due to a lack of appreciation of the errors involved. The values of thermal conductivity for a number of refractories are given, as obtained by a new type of apparatus designed to eliminate to a considerable extent the errors of measurement. However, it is believed that these values may have an error as high as ± 25 % for the better heat conductors; so there is still much work to be done in developing a method for measuring thermal conductivity with the precision usual in other physical measurements.
THE DETERMINATION OF MULLITE IN A PORCELAIN BODY1
Authors: McVay T. N.
Published: June 2006

An attempt was made to separate mullite crystals in a porcelain by the use of hydrofluoric, sulphuric, and phosphoric acids. Chemically pure mullite was treated in the same manner. The results of such a separation were not satisfactory.
THE EFFECT OF CALCINED CYANITE IN PORCELAIN BODIES1
Authors: Mcdowell Famual J. , Vachuska Edward J.
Published: June 2006

A study was made of the physical properties of porcelain bodies containing varying amounts of calcined cyanite (mullite), feldspar, and flint with a constant content of 50% clay. All bodies were made up under uniform conditions and fired to their proper maturing temperatures which varied from cones 8 to 20. Moduli of rupture for correctly fired bars varied from 5100 to 12,100 Ibs. per square inch, those bodies high in mullite being the strongest. The coefficients of linear expansion between 30 and 844° C varied from 4.3 × 10−6 to 6.6 × 10 ×−8 6, those bodies high in mullite having the lower expansion. Thirty per cent or more calcined cyanite (50% or more total mullite as figured from chemical composition) must be present to obtain a marked effect on either of these properties. Triaxial diagrams show the position of various typical porcelain bodies and how they might be affected by additions of this material.
THE HEAT REQUIRED TO FIRE CERAMIC BODIES1
Authors: SIMPSON HAROLD E.
Published: June 2006

The interval specific heats of twenty‐three refractory clays of various types from Pennsylvania, Ohio, Maryland, Kentucky, Missouri, Colorado, and New Jersey were calculated as well as ten clays used in the Bureau of Mines investigation “The Burning Problems of Industrial Kilns.” This group included fire clay, shales, and surface clays.

The results showed that there was very little difference in the interval specific heats at 1000 °C between the various types of fire clay, shales, and surface clay. The values ranged from .425–440.

In the Bureau of Mines investigation the average kiln efficiencies were calculated to be about 18%; using the corrected figures obtained for interval specific heats, the average kiln efficiencies were found to be about 29%.
A PRELIMINARY STUDY OF CERAMIC COLORS AND THEIR USE IN VITREOUS ENAMELS1
Authors: Harrison W. N. , Harthshorn T. D.
Published: June 2006

This report deals with the results obtained from a study of ceramic colors as used in vitreous enamels. Numerous coloring stains were produced and used in various enamel compositions. The batch formulas of the stains are given, and methods of preparation described.

To obtain uniformity of texture of the colored enamels, and to insure accuracy of duplication in preparing successive batches of a given stain, it was found desirable to (a) accurately duplicate time and temperature of calcination, and in some cases furnace atmosphere; (a) wash the stains free from soluble matter after calcination; (c) grind and pass them through a fine screen before use; and (d) keep the enamel composition constant.

Several of the stains were produced on a relatively large scale and tested commercially under plant conditions. These gave excellent results.
SPALLING AND LOSS IN COMPRESSIVE STRENGTH OF FIRE BRICK1
Authors: Goodrich Hobert R.
Published: June 2006

A preliminary report of the loss of compressive strength when fireclay brick from the Pacific Northwest were subjected to a series of heat treatments to 1350° and 1250°C. It illustrates some of the variations of heat treatment in the manufacturer's kilns and the differences between the high siliceous type of fire brick and the vitrifying clay type with lower free silica content. It is possible that a satisfactory spalling test may be developed in this direction.
DRY GRINDING CLAY TO EIGHTY‐MESH1
Authors: Albery D. F.
Published: June 2006

A description of two installations for grinding a terra cotta clay to 80‐mesh is given. The necessity for fine grinding is explained and the difficulties encountered in development of process are enumerated. Advantages of finely ground clay and the use of air separation are described.
URANIUM OXIDE COLORS AND CRYSTALS IN LOW TEMPERATURE GLAZE COMBINATIONS1
Authors: Lorah James R.
Published: June 2006

A study has been made of the color and crystallization of some uranium, lead, sodium, and boron glazes fired in a pure oxidizing atmosphere, both alone and with the addition of certain inorganic compounds. The colors obtainable are yellow, orange, red, green, brown, and black. By using only uranium oxide and red lead it is possible to produce any shade from light yellow to dark orange or red. About 10% of yellow uranium oxide is required to produce the deepest shade of orange.

A study has been made of the crystals found in these glazes and the effect on them of adding clay and certain other compounds, and of increasing the time of firing. It is shown that the volatilization of lead is a very great factor in the preparation of crystalline structures.
ADSORPTION AT CRYSTAL‐SOLUTION INTERFACES
Authors: Keenen F. G. , France W. G.
Published: June 2006

The present work is a continuation of the study of adsorption processes at solution‐crystal interfaces. It consists of an investigation of the adsorption of dyes and gelatin by the various faces of potassium alum. The growth ratios of this alum were measured both in the presence and absence of the dyes and gelatin. It was found that Bismarck Brown and Diamine Sky Blue greatly affected the growth rates of the cube faces and also modified the crystal habit. This effect is explained on the basis of the ionic structure of the faces and the presence of polar groups in the dyes. The growth ratio V100/V111 for pure potassium alum was found to be 1.61.
VITREOUS ENAMEL SLIPS AND THEIR CONTROL1
Authors: Harrison W. N.
Published: June 2006

The purpose of this work was to study vitreous enamel slips in order to develop adequate means for measuring and controlling their consistency under plant conditions.

A suitable laboratory means for determining their consistency was first selected, and the effect of various factors upon consistency determined by this means. In order to learn something of the mechanism by which changes in consistency take place, observations were made upon the physicochemical nature of the different phases of several typical slips; also, the state of flocculation of the finer particles of suspended matter was observed under different conditions known to produce slips of different consistencies.

A simplified method of determining consistency, suitable for plant use, was then devised, and the work carried into the field. This simplified means was put into use in conjunction with other tests, in order to obtain data for correlating consistency as determined by this method with the working properties of the slips.
THE POSSIBILITIES OF THE TUNNEL KILN FOR SEWER PIPE1
Authors: Richardson W. D.
Published: June 2006

The questions of whether enough sewer pipe could be set on cars and safely pushed through a tunnel kiln to make this type of kiln practicable for firing sewer pipe, and whether salt glazing would be practicable in one are discussed. The modifications necessary in a Richardson compartment tunnel kiln to make it practicable for this purpose are enumerated and explained.
PRODUCER GAS IN CONNECTION WITH FIRING FIRE BRICK1
Authors: Orth H. S.
Published: June 2006

Features in connection with firing fire brick are discussed. In tunnel kiln firing a high temperature at the charging end is essential. Desired features of producer gas firing are discussed and a producer gas fired tunnel kiln installation is described in detail. It is shown that production capacity is dependent on the charging end temperature.
NATURE AND ORIGIN OF REFRACTORY CLAYS1
Authors: Ross Donald W.
Published: June 2006

A conception of the nature of refractory clays, and a supposition as to the character of their origin.
SOME OBSERVATIONS ON THE AGING OF ENAMELS1
Authors: Wolfram H. G. , Turk R. H.
Published: June 2006

The tendency toward more rapid production of enameled ware has reduced to minimum the time allowed in most plants for aging of enamels. Aging of the enamel slip allows the clay to become thoroughly slaked, adsorb the larger enamel particles, and thus prepare it for its cohesion to the metal base. Aging or soaking of the clay before use is an excellent substitute for part of the time consumed in aging the enamel slip. Observations of results obtained in commercial application of enamels has lead to the following conclusions: (1) Enamels should be aged before use in order to gain the full benefit of the adsorption properties of the clay and enamel colloids. (2) If the proper time of aging of enamels cannot be allowed, at least the clay should be brought to fine state of subdivision by aging or soaking in water. (3) If aging is not allowed in some form, the enamel usually is not as easily applied with the ordinary handling encountered in average production. (4) If aging of the clay is allowed there is quicker turn over of the stock enamel in the mill room.
A STUDY OF SOME FACTORY PROCESSES1
Authors: Kraner Hobart M. , Fritz E. H.
Published: June 2006

This paper deals with some ceramic plant methods and machine design which are either wasteful of labor or power. The following are discussed and in some cases actual examples existing were subjected to calculation of the waste involved. Some of these cases remedied were: (1) raw material handling, (2) small power plant costs: boiler practice and plant power factor, (3) screens, (4) steam pipes, (5) heat insulation, (6) steam jets, (7) sagger presses, and (8) steel dies.
SOME NEW IDEAS IN CLAY WORKING1
Authors: Straight H. R.
Published: June 2006

The ideas which the author intends to try out on a plant scale are as follows: (1) roll crushing of the planer product, (2) use of a modernized soaking pit with pug mills, (3) heating pugged clay before molding, (4) air evacuation during pugging, (5) setting ware on kiln cars and running them through a humidity drier at a slow variable rate, 6) use of a wider tunnel kiln, especially for hollow ware, with special circulating features, and (7) mechanical handling of fired ware. Each idea is taken up and discussed in detail; all are along lines of eliminating manual effort, saving fuel, and increasing production per dollar invested.
SOME EFFECTS OF CAREFULLY ANNEALING OPTICAL GLASS1
Authors: Tilton L. W. , Finn A. N. , Tool A. Q.
Published: June 2006

The apparent lack of optical homogeneity in good optical glass may be the result of small differences in temperature during annealing. That this can be eliminated to a large extent by careful furnace control has been demonstrated. Furthermore, this may be done without appreciable change in the average index of refraction if the “thermooptical” constants of the glass are predetermined.
PLASTICITY OF CLAY1
Authors: Jenks Leon E.
Published: June 2006

The cause of plasticity of clay is the formation in the moistened clay of a continuous external phase through the action of water in making gelatinous the material that forms the enveloping surface around the non‐gelatinous particles and aggregates present in the clay. Peptizing and flocculating effects of electrolytes and organic matter are discussed. A possible method for evaluating the relative plasticity of clays and the results obtained on some commercial clays using this method, are given.
A WASTE HEAT DRYING SYSTEM INVOLVING RECUPERATION1
Authors: Windsor W. T. , Westendick F. C.
Published: June 2006

In an attempt to eliminate the smoke nuisance created by operating a brick plant within the limits of a city, a successful smoke eliminator and a waste‐heat drying system involving recuperation were developed after some experimenting on old and new methods. The construction and arrangement of the recuperator is described as follows: A complete double‐deck duct system was built carrying the combustion gases in the lower half and the waste heat in the upper half. In this system a damper chamber is constructed a t each kiln where the outlet flue leaves the kiln. The kiln outlet flue enters this chamber on the one side and the gas and waste‐heat ducts one above the other leave on the other side. Both of these ducts are fitted with dampers. The construction of these chambers and the main duct is described. The advantages, limitations, and cost of this system are discussed.
THE HEAT BALANCE OF A GLASS TANK FURNACE1
Authors: Pike Robert D. , West George H.
Published: June 2006

A seventy‐two hour test was carried out on a continuous side‐fired regenerative glass tank furnace with five oil burners on each side. A novel feature of this furnace was the insulation of the entire silica brick cap by means of a high temperature insulating brick. A complete record of the furnace operation during this period is given. Temperature measurements were made a t various points in the furnace and regenerator. A feature of the temperature observations is the great magnitude of the radiation correction when hot gases are flowing through passages lined with cooler brick work. The method described by Kreisinger and Barkley was used in making these measurements. This method could be employed for direct reading of true temperature at any point in the regenerative system. The heat balance of the complete furnace system between points at bottom of regenerators is given. Possible savings of fuel amounting to 14% of the total fuel burned are shown. An important fact brought out by this heat balance is that leakage through furnace brickwork is as prolific a source of heat loss as flow of heat through them by conduction.
THE PORES IN BRICK1
Authors: Easter G. J.
Published: June 2006

The mathematical theory underlying the reduction of heat losses through bricks by means of finer subdivision of the pores is briefly reviewed. For comparison of the size and number of pores in different bodies the resistance to the Bow of air through materials is measured and the pores arbitrarily considered to be replaced by an equivalent volume of parallel cylindrical capillaries extending through the brick and of such size and number as to offer equivalent resistance to air flow. The dimensions of these capillaries are then computed. The method is applicable only to bodies having open pores.
NOTE ON THE VAPOR ABSORPTION OF A FIRED EARTHENWARE BODY1
Authors: Deeds C. L.
Published: June 2006

Specimens of an earthenware body fired at three temperatures were placed over a 10% sulphuric acid solution for 36 days and the gain in weight determined. Up to a certain limit of porosity the absorption is proportional to the porosity, but the body with the highest absorption, 20.25% took up a relatively higher amount of water. With an absorption of 8.81%, the maximum amount of water vapor taken up was 0.13%. With 10.8% absorption the water vapor taken up was 0.16 and with 20.25% absorption it reached 0.54%.
CLAYS AND CLAY DEVELOPMENT OF LOUISIANA1
Authors: Whittemore J. W.
Published: June 2006

The history of the surface geology of Louisiana is given. The various geological formations of the state which contain clay that might be used to manufacture ceramic products are described. The properties of the clays that are of commercial value are considered. The cheap labor, cheap gas, good markets, and good transportation facilities of the state afford excellent possibilities for ceramic manufacturers.
THE DEVELOPMENT OF THE SHALE PLANER1
Authors: Tefft C. Forrest
Published: June 2006

The development of the shale planer from the first machine built by J. M. Powell fourteen years ago to the latest type is traced. Examples of applications at various plants are cited. Actual operating cost data on some of the latest type machines are presented. The advantages of a shale planer over other gathering machinery are discussed.
EFFECT OF HEAT TREATMENT ON DIATOMACEOUS EARTH1
Authors: Kraner Hobart M.
Published: June 2006

This paper deals with the heat treatment of diatomaceous earths collected from a few commercial deposits throughout the country. It was originally intended to study the effect of heat treatment upon the various types of diatoms which occur in these deposits and the study was not intended to have any particular practical application. The results of the study indicate that the change of structure incident upon higher heat treatment is more dependent upon the chemical composition (impurities) than it is upon the diatom structure. An air‐floated sample which was quite pure showed little deterioration up to 1300°C.
MANUFACTURE OF STONEWARE AND FLOWER POTS IN A SMALL PLANT1
Authors: Kirkpatrick Frank A.
Published: June 2006

A brief description of the manufacture of household stoneware and flower pots in a 3‐kiln plant in the Southwest and of improvements made in bodies, glazes, and processing.
FUEL MIXING WITH CLAY1
Authors: GANGWERE R. C.
Published: June 2006

The question of fuel cost reduction is very pertinent. Mixing cinders with clay produced a granular structure which stimulated drying and reduced firing expense. Other methods tried are mentioned.
PROGRESS REPORT ON CAST IRON FOR ENAMELING PURPOSES1
Authors: HARRISON W. N. , Saeger C. M. , Krynitsky A. I.
Published: June 2006

Blisters on enameled cast‐iron ware may be traced either to faulty enamels and process of application or to the castings themselves. This investigation is concerned with the latter type of blisters. Differences in the blistering tendencies of different sets of castings were clearly brought out by an enameling test which included a variety of firing treatments. Using this test it was found that not only do different irons have different blistering tendencies, but successive heats of the same iron may have different blistering tendencies. The main source of blisters from the irons used in this work was overcome by removal of a thin surface layer of the castings, through either mechanical or chemical means.
THE EFFECT OF LEPIDOLITE IN A HIGH TENSION ELECTRICAL PORCELAIN BODY1
Authors: Twells Robert
Published: June 2006

Lepidolite is a lithium mica which has had considerable commercial application in glass and enamels. Its use in porcelain has not been tried to any great extent. This work covers the replacement by lepidolite of the feldspar in a high tension electrical porcelain. The results show that changing the RO of the standard body by molecularly replacing K2O by Li2O raises the vitrification temperature of the body, but that replacing feldspar directly pound for pound by lepidolite greatly lowers the vitrification temperature of the body. Lepidolite gives porcelains having a fine appearance and extreme whiteness. The most important property noted is an improvement of the bodies containing lepidolite in resistance to thermal shocks. Owing to its higher cost it is unlikely that lepidolite will be used in porcelains except in small proportions with feldspar to produce bodies having special properties. As hitherto the most important applications of lepidolite will doubtless be in glasses and enamels where full benefit can be secured from its fluorine content and low fusion temperature.
KILNS, FURNACES, BODIES, AND GLAZES FOR SMALL COMMERCIAL PRODUCTION AND EDUCATIONAL WORK1
Authors: Cox Paul E.
Published: June 2006

Drawings and specifications for two small commercial kilns, one small test kiln, and a frit furnace are shown. Glazes suitable for use in the kilns are described. Shales and No. 2 fire clays are suggested for use. Reference is made to ware of commercial quality now being made in kilns of the kind indicated. Two sorts of copper red glazes are discussed and reference is made to the use of salt in effecting changes in the character of glazes. Fritted mat glazes are discussed and endorsed as superior to the raw sort, because of greater flexibility. A kiln atmosphere charged with vapors of common salt effects interesting changes in both the character of glazes and the usual colors produced by the commonly used oxides. A normally glossy, bright, and clear glaze becomes a vellumlike mat when fired in the presence of NaCl under certain conditions. A positive method of producing low‐fired copper reds and lusters is described.
A LESSON IN DESIGN FROM THE SANDHILL POTTERS OF NORTH CAROLINA1
Authors: Payant Felix
Published: June 2006

The Jugtown pottery made by the Sandhill potters of North Carolina is described. The design of the pottery is analyzed and the making, glazing, and firing of this ware along with the equipment and raw materials used are described.
CONTINUOUS ENAMELING FURNACE1
Authors: Owen ByW. O.
Published: June 2006

Details are given of the moving of ware through a new continuous counterflow furnace for fusing enamel. Among the advantages of this new type are smaller loss of ware and saving in time and money.
TESTING OF A RED QUARRY FLOOR TILE KILN1
Authors: HarryVauqehan ByW.
Published: June 2006

A practical test of a round downdraft kiln firing red quarry floor tile is given. The results showed a considerable saving in fuel and time and an increase in the quality of ware amounting to more in value than the saving in fuel. An investigation of firing conditions in the average large plant using similar kilns is recommended as an investment which will yield dividends.
A WARPAGE STUDY OF TERRA COTTA CLAYS1
Authors: Murphy R. M.
Published: June 2006

Several types of clays, which compose a commercial terra cotta body, were studied for warpage during drying and firing. Results of warpage test show properties that each clay gives to the terra cotta body.
LENGTH OF TIME OF DIE USE AS AFFECTING SIZE OF FLOOR TILE1
Authors: Tailby Roland V.
Published: June 2006

A description of a factory investigation to determine the practical life of dies used in pressing one‐inch hexagonal tile.
WHITE ENAMEL AND GRAY HAIR1
Authors: Cooke R. D.
Published: June 2006

The causes of opacity are discussed and examples listed. The chief cause is the great difference in indices of refraction of materials intimately mixed. The explanation of white enamels is given, discussing the effect of thickness on the reflection factor, and the intrinsic whiteness of enamels.
THE DEVELOPMENT OF A KILN FOR FIRING SEWER PIPE1
Authors: Clemens E. F.
Published: June 2006

Full description is given of a kiln for firing sewer pipe, with dimensions and innovations which have proven best. The use of smaller fire boxes tends to prevent overfiring to give hotter and more complete combustion, and to prevent roughness.
PRACTICAL MINING PRINCIPLES WHICH ARE FREQUENTLY OVERLOOKED1
Authors: Otstot E. D.
Published: June 2006

Practical problems of drainage, timbering, haulage, and loading in clay mines are discussed. Suggestions are given for saving time, labor, and expense.
ELIMINATION OF SEGREGATION IN DRUMS1
Authors: Easter G. J. , Magrum C. M.
Published: June 2006

Segregation of grits of different sizes was practically eliminated by the insertion of small tangential cylinders (3‐inch diameter) extending from top to bottom of the drum while it was being filled.
RAW YELLOW GLAZES FOR TERRA COTTA AND DEVELOPMENT PHENOMENA1
Authors: Squier L. R.
Published: June 2006

A study made for the purpose of developing raw yellow colors for terra cotta, using two glaze bases with rutile, barium chromate, and uranium oxide introduced as sodium uranate, is described. Results obtained and development phenomena observed are discussed.
A PETROGRAPHIC STUDY OF SOME SLAGS FROM BOILER FURNACES1
Authors: McDowell Samuel J. , Lee H. C.
Published: June 2006

Observations are based on a microscopic study of the effect of slags, particularly those of an Illinois coal, on refractories. A mineralogical relation is shown between the slag and the refractory used. The principal phases present in a cooled slag are: (1) a plagioclase feldspar, (2) magnetite or hematite, (3) mullite with iron oxide in solid solution, (4) glass. The so‐called “interface” between slag and refractory is largely crystalline upon cooling and consists principally of mullite which, surrounded by the slag, has grown from fine needles in the refractory to larger ones. In high alumina refractories where diaspor is present, the stained interface is much thicker and grains of corundum are formed. This zone of crystallization may be conducive to spalling. The effect of slags on various refractories is discussed.
STUDY OF THE PROPERTIES OF SIMPLE ENAMEL GLASSES1
Authors: Andrews A. I.
Published: June 2006

Three component glasses of the systems Na2–B2O3–SiO2 and Na2O–PbO–SiO2 were investigated as to acid‐resisting properties. An increase in silica in general improves the acid resistance. The effect of Na2O, B2O3, and PbO on the acid resistance of an enamel is dependent on the composition to which these oxides are added. Some of these enamels showed considerable promise as acid‐proof enamels.
THE DETERMINATION OF AIR IN PLASTIC MIXES1
Authors: Cartwright Vance
Published: June 2006

This article describes a laboratory procedure for the determination of air in wet clay mixes.
STOKER APPLICATION TO THE CAR TUNNEL KILN1
Authors: Harrop Carl B. , Orth Howard S.
Published: June 2006

Presents arguments for use of mechanical stoker on continuous kilns. Describes first practical application of mechanical stoker to the car tunnel kiln used for ceramics and gives results.
CLAY SEWERPIPE MANUFACTURE1 VI. Heat‐Balance Determinations
Authors: Arnold R. E. , Duncombe George H.
Published: June 2006

Heat‐balance determinations were conducted on a number of sewerpipe kilns and the kiln efficiencies were found to vary from 14.97% to 29.03%. The method of calculating the heat balance is described in detail. Kiln efficiencies for individual periods range higher for the second period in most cases with some of the kilns reaching upward of 40% efficiency. In general as the kiln reaches higher temperatures the kiln efficiency decreases due to increasing stack and kiln structure losses. In all, thirty‐four kiln tests were conducted in six plants in various sections of the country, in twenty‐six of which heat‐balance calculations were made, the remainder being auxiliary tests giving only general operating data such as tonnage of ware, fuel consumption, temperature schedule, and ware analysis.
CLAY SEWERPIPE MANUFACTURE VII. Low Temperature Oxidation1
Authors: Arnold R. E. , Duncombe George H.
Published: June 2006

Data of plant and laboratory experiments on rate of oxidation of carbon found in sewerpipe clays are presented. The effect of some metallic oxides as catalysts in the low temperature combustion of coal is investigated. The difference in rate and completeness of the combustion or volatilization of the various forms of carbon shown in the laboratory studies suggests one explanation of why the clays of the plant experiments oxidize with difficulty at higher temperatures, viz., that the material which forms the black core is of the type of carbon compound which burns readily at low temperatures, and that at higher temperatures it is “cracked” or changes into one of the forms of carbon which burns slowly.
CLAY SEWERPIPE MANUFACTURE1 VIII. Measurement of Draft Distribution
Authors: Parmelee C. E.
Published: June 2006

A method used in measuring the draft distribution in sewerpipe kilns is described and the significance of draft measurement in kiln studies is discussed. In the progress of the kiln studies several types of kiln bottoms were investigated. These ranged from one extreme to the other in the type and arrangement of flues and openings. The kilns studied had ring, spoke, spider, or “T” flue systems, together with solid or open‐feature walls, and in some cases a double‐feature wall system. Draft‐distribution studies of these types of construction brought out widely varying conditions. The possibilities offered in correcting faulty conditions by the use of this method of measuring the distribution are discussed.
VISCOSITY MEASUREMENTS IN GLASS1
Authors: Lillie Howard R.
Published: June 2006

The concentric cylinder method, described in a previous paper, has been used in the measurement of viscosities in molten glass. The apparatus and method of measurement are fully described. Comparisons are made between results obtained and those of English, Stott, and Washburn. Quite good checks are found in comparisons with English and with Stott, but results obtained in comparing with Washburn indicate a difference supposedly due to his use of a variable calibrating factor. Measurements made by the use of a falling sphere give values of viscosity 25 to 50% higher than those given by the concentric cylinders in the same glasses. This may be due to the extended extrapolation of Ladenburg's correction for finite boundaries.
A DEFORMATION STUDY OF COBALT OXIDE‐ALUMINA‐SILICA MIXTURES1
Authors: Felton Thomas M.
Published: June 2006

A deformation study of CoO‐Al2O3‐SiO2 mixtures was made to determine the fluxing effect of cobalt in such silicate mixtures as glazes and enamels. The deformation eutectics for cobalt and alumina, cobalt and silica, and cobalt‐alumina‐silica were determined and isothermal diagrams drawn.
FURTHER DEVELOPMENTS ON TORSIONAL APPARATUS FOR MEASURING PLASTICITY1
Authors: Parmelee C. W. , Rudd R. D.
Published: June 2006

A critical study of the apparatus has been carried on to reduce variations in results due to manipulation. Specimens were made by squeeze molding in saturated plaster molds instead of forming in the hands. The loading device was changed so that the stress could be increased continuously instead of intermittently as heretofore. The specimens were designed so that the ratio of the maximum stress in the outer fibers of the circular section was to that of the square section as 3.8 is to 1. Clays having the same water content were compared by studying the slopes of the stress‐strain curve sup to the proportional limit.
THE RATE OF OXIDATION OF PORCELAIN AND BALL CLAYS1
Authors: Kraner Hobart M. , Fritz E. H.
Published: June 2006

In this study the rate of CO2 evolution was determined by passing a 4% oxygen to 96% nitrogen gas mixture over a bar of clay or porcelain while this bar was being heated at an approximate rate obtained in the ceramic kilns. The water and CO2 evolved were collected in phosphorous pentoxide and soda lime, respectively, and the respective apparatus weighed each half hour during the length of the run. It was found that oxidation took place rapidly between 200°C and 550°C in both clay and porcelain. This is much different from what has been generally understood to be true, for in all the ceramic literature 750°C seems to be indicated as the most efficient temperature at which oxidation proceeds. It appears that oxidation of ceramic ware such as these can take place at much lower temperatures and with much greater economy in firing practice.
SOME ASPECTS OF PLASTICITY AND RELATED PROPERTIES OF CLAYS1
Authors: Irving D. R. , Dietrich W. F.
Published: June 2006

This paper presents the results of Talwalkar‐Parmelee plasticity measurements of a number of clays, and an interpretation of the results in the light of data on dye adsorption, water of plasticity, drying and firing shrinkage, and dry transverse strength. The clays studied are mainly from California, but tests of a few more widely‐known clays from other sources are included for the purposes of correlation. Some data are given to show the effect of the addition of fine sand on the plasticity of a clay. The effect of variations in the water of plasticity is also considered.
CYANITE AS FOUND IN WESTERN NORTH CAROLINA1
Authors: Fessler A. H. , McCaughey Wm. J.
Published: June 2006

This article describes briefly the deposits, formations, geology, and economic value of the mineral cyanite as found in western North Carolina.
VANADIUM AND MOLYBDENUM COMPOUNDS IN CLAYS1
Authors: PALMER L. A.
Published: June 2006

Eight different light‐firing clays and shales containing small amounts of insoluble vanadium and molybdenum compounds were studied. It was found that during firing, soluble salts of these elements were formed which later appeared as a green‐yellow efflorescence on the fired clay. The color of the efflorescence was chiefly due to alkali vanadates.

It was found that the use of either sodium fluosilicate or calcium fluoride is effective in eliminating the green‐yellow efflorescence. The use of these chemicals is usually a more economical procedure than either hard firing or the use of lead compounds. The results of various trial firings made with clays to which were added varying amounts of several different chemicals are given.
THE INSULATION OF ROOFS OF GLASS FURNACES
Authors: Pike Robert D.
Published: June 2006

It is unjustifiable to assume that a furnace roof cannot be safely insulated. The principal variables controlling the possibility of safe insulation are: (1) temperature of bath below melting point of silica brick roof; (2) transparency of the atmosphere within the furnace, i.e., no possibility of impingement of dense hot flames. The data of this paper are taken from observations on a glass tank furnace in which the combustion rate (B.t.u. per cu. ft. per hr.) is very low. A testing method is described which will show whether or not insulation is safe for any given furnace, considering only the temperature of the inside face of the brick as affected by the application of insulation. The possibility that if the roof is insulated the progress of fluxing of the silica brick by dust and fumes within the furnace may be accelerated because the higher mean temperature of the brick is considered. In the furnace observed, corrosive dust and fumes were in the gases to a considerable extent, yet no unusual deterioration of the roof brick was noted after three years of insulation under continuous operation.
SMOOTH‐SURFACE TILE1
Authors: Schory V. S.
Published: June 2006

A series of experiments is described by which a body suitable for the manufacture of smooth‐surface tile was developed. The effects of certain raw materials and of the firing conditions are reported.
PYROPHYLLITE, A NEW CERAMIC RAW MATERIAL1
Authors: Shelton G. R.
Published: June 2006

The relationship among the minerals pyrophyllite, kaolinite, and steatite together with a statement of the properties of pyrophyllite are given. The North Carolina deposits of pyrophyllite are briefly described. A preliminary report is made on tests now being conducted to determine the possible use of pyrophyllite as a constituent in whiteware bodies.
THE ACTION OF FLUORINE IN ENAMEL SMELTS1
Authors: Wilcox H. G. , Westendick F. C.
Published: June 2006

It is proved that all fluorine is not volatilized from enamels and that the duration of smelting and viscosity of smelt affect the amount driven off. These facts were determined by quantitative analysis of enamels of varied compositions smelted under varied time treatments.
NEW METHOD OF DIRECT FIRING GLAZED CERAMIC BODIES1
Authors: Whitaker F. A.
Published: June 2006

A description is given of the construction, operation, and economies of an adaptation of Carboradiant principle of heating to a rectangular kiln used for firing sanitary ware. Improvement in control, increase in fist quality ware, and economy of fuel resulted.
SOME LEADLESS BOROSILICATE GLAZES CONTAINING NICKEL OXIDE1
Authors: Holscher H. H.
Published: June 2006

The literature pertaining to the use of nickel oxide in all types of glazes is briefly reviewed. A study of the effect of the various glaze constituents on the color and other properties of some leadless borosilicate glazes containing nickel oxide as a colorant is given. Nickel oxide has not proved useful in glossy non‐opaque glazes. It is not recommended for use where a deep (dark) color is desired but can be made to produce very pretty opaque glazes, light tan in color and of a semimat character.
GREATER EFFICIENCY IN TUNNEL DRIERS1
Authors: Richardson W. D.
Published: June 2006

The chief causes of inefficiency in waste‐heat tunnel driers are (1) the cold bottom in the upper half of tunnels and (2) the hot air which enters the tunnels immediately goes to the top and does not return to the bottom but passes over the top of the ware and emerges at the receiving end of drier only partially saturated. A method is shown of insuring a hot bottom throughout the tunnel and of recirculating the air in the tunnel by means of small fans cooperating with steel baffles on the end of every thud ear, these baffles registering with beams across the top of the tunnel and with pilasters on the sides, thus dividing the tunnel into compartments, with alternately up and down circulation through the ware.
GLOST WARPING OF WHITE WALL TILE1
Authors: Teffi T. Dwight
Published: June 2006

A method for measuring the warpage of wall tile is presented and a study is made of the warping results obtained from variations of glaze composition. Conclusions are drawn from tests with zinc oxide, calcium, barium, and magnesium.
THE ACCURATE MEASUREMENT OF HIGH TEMPERATURES1
Authors: Forsythe W. E.
Published: June 2006

The standard temperature scale is defined and methods of realizing it both in laboratory and in factory practice are outlined. Methods of measuring temperature from very low values to the highest obtainable are described. The use of thermocouples, the errors encountered in the use of both base metal and rare metal thermocouples, and the methods used to avoid these errors are discussed. Thermocouples are useful in measuring temperatures up to about 1000 to 1500°C. Beyond the range of thermocouples and sometimes even in this range it is necessary to use some means of measuring temperature that depends on the energy radiated from the source under consideration. For this class of work the optical pyrometer is recommended as one very good method.

Different forms of optical pyrometers are discussed and the advantages and disadvantages of these types are pointed out. The conclusion is reached that for many types of work the disappearing‐filament type of optical pyrometer has certain advantages over other forms. Some of these advantages are pointed out and reasons given for the selection of this pyrometer. The necessity for the use of a monochromatic screen with a pyrometer is discussed and a list of the various screens available are given. Reasons are given for the general choice of a red screen for this work. In the use of an optical pyrometer it is at times necessary to know something concerning the wave‐length of the light used. This brings up the question of the effective wave‐length of the screen used. The effective wave‐length is defined and methods given for determining and using this effective wave‐length in optical pyrometry. It is shown that with a well‐calibrated screen just as definite results can be obtained as with a spectrometer for determining wavelength, and the advantages of the screen over the spectrometer are set forth.

Methods of calibrating optical pyrometers are discussed which bring in the idea of a black body. Methods of realizing the theoretical black body are given together with some experimental results along this line.

The use of absorbing screens in extending the scale of an optical pyrometer is outlined and methods are given of obtaining the transmission of the absorbing screens so that it is easy to calculate the extension of the temperature scale with a particular screen. The kind of an absorbing screen needed for this work is shown and the advantages and disadvantages of the absorbing screens are given.

Accuracy tests are included in which it is shown that very good agreement can be obtained in the use of a disappearing‐filament optical pyrometer by untrained or slightly trained observers. Results are also given to show what accuracy may be expected from experienced observers from this form of pyrometer.
GEOLOGIC RELATIONS OF THE DIASPORE AND FLINT FIRE CLAYS OF MISSOURI1
Authors: McQueen H. S.
Published: June 2006

Sink‐hole type deposits filled with flint fire clay have been known in the Ozark region of Missouri for many years. Within the last ten years, an associated clay, formerly discarded as waste, but now recognized as diaspore clay has been developed. The paper outlines the general geology of the district and discusses the clays and mode of occurrence of the deposits, Brief mention is made regarding future production and probable developments in this interesting district.
A CONE FUSION MUFFLE FURNACE FOR HIGH TEMPERATURE WORK1
Authors: Baumann Henry N.
Published: June 2006

A laboratory type muffle furnace in which the muffle (inside dimensions 9 by 6 inches) was built of standard “Refrax” brick and heated by means of two slotted graphite electric resistors, has been in use for over a year in the Research Laboratory of The Carborundum Company at Niagara Falls. Although specifically designed for cone fusion studies, in which work it is very successful, it can be used for other laboratory work especially at high temperatures (up to at least 1600°C)such as small fusions, heat treatment, etc.
DETERMINATION OF THE SOURCE AND MEANS OF PREVENTION OF STONES IN GLASS
Authors: Insley Herbert
Published: June 2006

The microscopic characteristics of different crystalline materials occurring as stones or lumps in glass are described and photomicrographs of stones originating from devitrification of the glass, incomplete solution of batch constituents, and incorporation in the glass of refractory wall material are reproduced. Methods of determining the location in the glass‐making system of the source of stones, using microscopic as well as other methods, are given. Means of prevention or elimination of the stones are suggested.
CORRECTION OF AN EXTREME CASE OF CRACKING IN THE DRYING OF BRICK1
Authors: Fréchette Howells , Phillips J. G.
Published: June 2006

I. In the manufacture of stiff‐mud brick from a highly colloidal clay of low permeability to water, drying breakage was extremely high even though the drying was conducted at a very slow rate under high humidity conditions. Laboratory investigation yielded two methods of correcting the faults: (1) Preheating the clay for half an hour at a temperature between 400 °C and 500 °C increased the permeability to such an extent that brick made from the preheated clay could be dried rapidly without cracking.

(2) Coagulating chemicals, such as aluminium chloride, ferric chloride, sodium chloride, and hydrochloric acid, in conjunction with moderate additions of grog, increased the permeability and thus improved the drying properties of the clay. II. Plant scale tests using ferric chloride, sodium chloride, and grog resulted in the production of brick which could be dried safely in a reasonable time. The fired brick were improved in quality as to strength and color. III. The chemical treatment of the clay using 1% ferric chloride and 0.5% sodium chloride with 10 to 15% grog was adopted for plant operation and resulted in increased production, lower cost of manufacture, and improved quality of product.
SOME WASTE‐HEAT DRIER CALCULATIONS AND CHARTS1
Authors: Westman A. E. R. , Mills R. G.
Published: June 2006

Equations were developed which, when used in conjunction with hygrometric charts, enabled the usual waste‐heat drier calculations involving heat supply and water removal to be performed by direct substitution. These equations were used in preparing charts showing the effect of (1) atmospheric humidity conditions, and (2) air discharge temperature on the operation of a typical waste‐heat drier. The advantages which might result from the control of the initial moisture content of the air used in drying and the feasibility of using silica gel for this purpose are discussed. Changes in drier design which would permit higher exit temperatures for the air used in drying are suggested by the outcome of the calculations.
DRYING HEAVY CLAY PRODUCTS IN A PROGRESSIVE DRIER USING RADIATED HEAT AND MECHANICAL CIRCULATION1
Authors: Straight H. R.
Published: June 2006

The principles which should be followed for the safe drying of clay products are discussed. These are as follows: (1) direction of air circulation, (2) rate of air circulation, (3) humidity, (4) the use of clear air, (5) temperature of air in drier. A pallet system is proposed as an ideal manner of arrangement in the drier for drying brick, hollow tile or drain tile, and similar heavy clay products.
PHYSICAL TESTS FOR VITREOUS ENAMELS. I1
Authors: Kinzie C. J.
Published: June 2006

Methods and apparatus for determining certain physical properties of vitreous enamels are described. These properties are as follows: (1) resistance to thermal shock of vitreous enamels applied to flat surfaces, (2) resistance to mechanical impact of vitreous enamels, (3) resistance of vitreous enamels to abrasion.
THE EFFECTS OF SODA, BARIUM, AND ZINC ON THE ELASTICITY AND THERMAL EXPANSION COEFFICIENTS OF GLASS1
Authors: Fetterolf L. D. , Parmelee C. W.
Published: June 2006

An investigation is made of the effect, on the elasticity and expansion behavior of a base glass containing 60%, SiO2 and 40% Na2O, of replacing Na2O in this glass by ZnO and BaO, respectively. The elasticity and expansion factors of the two oxides, ZnO and BaO, are determined and compared with published results. Elasticity factors of 80 for ZnO, 35 for Na2O, and 55 for BaO are proposed. Cubical coefficient of expansion factors of 12.5 Na2O, 5.7 for BaO, and 1.85 for ZnO are also proposed. Neither the factors of Winkelmann and Schott nor those of English and Turner fit very well the results reported in this paper.
THE COMPRESSIVE AND TRANSVERSE STRENGTH OF BRICK1
Authors: McBurnby J. W.
Published: June 2006

This paper reports the compressive strength flat and on edge and the transverse strength of twenty‐seven makes of brick covering a range of conditions in method of manufacture and degree of firing. The attempt is made to correlate the variation in ratios of these different measures of strength with the various structural features of the check.
EFFECT OF TYPICAL SLAGS ON FIRE BRICK WITH A METHOD OF DETERMINATION CORRELATED TO SERVICE1
Authors: Grigsby Chester E.
Published: June 2006

In an investigation of the problem of producing refractories which would give maximum resistance to slags encountered in service, laboratory slag tests were made in a rotary slagging test furnace. A photograph and sketch of the furnace are given and the method of operation is described. A photograph of a typical test is shown and test data are given for typical high iron oxide, high lime, and high soda slags. These data include the numerical rating of ten test bricks in each case. Ten slag tests have been made with 50 different mixes, all in the field of fireclay and diaspore refractories.

Bricks of the brands which give best results in the laboratory were tested in service in malleable iron air furnaces, gray iron cupolas, and “bull” ladles where sodium carbonate purifier is used. Operating conditions are given and chemical analyses of slags presented in several instances. Special firing treatment was given a few bricks prior to service tests.

Excellent correlation between laboratory and service tests was obtained in cases where high‐temperature abrasion was not severe, demonstrating the reliability of the rotary furnace type of slagging test in predicting service results insofar as slag alone is concerned.

Of equal importance with the reliability of the slag test is the need of a reliable high‐temperature abrasion test. The data indicate that in many installations high‐temperature abrasion is the major cause of failures that are charged entirely to slag erosion.