Clay Slips Research Articles

流動鋳込の動的測定

流動鋳込の動的測定

泥漿の粘性の測定について

Constructing the similar type apparatus which was employed by H. Green and his co-workers to measure the flow properties of paintlike materials, observations upon the viscosity of clay slips were made at various solid concentrations, and the magnitude of “thixotropic break down” and “thixotropic set up” of these suspensions was decided.

鋳込特性の動的測定について

Constructing an apparatus being similar to that of Ferry and his co-workers which was used for measuring the dynamic properties of some hypolymers, the changes in dynamic viscosity and dynamic rigidity during the casting of clay slips for refractory crusibles were measured.It was found out that the casting properties were affected by(1) the distance from the mold surface, (2) the amount of defloculant, and(3) the quality of the defloculating electrolyte.

Fundamental Studies on the Spray Drying and Semi-Dry Press of Ceramics, (III)

The free-flowing phenomenon of spherical fine particles (48-88μ) obtained by spray drying of ceramic clay slips was studied. As a result, we concluded that the following expression is established between particle size dp, nozzle diameter d0 and equilibrium flow velocity Ve.Ve=Kd2(dp-d0)where, K is a constant defined only by the physical properties of particles and is so-called the coefficient of free flowing of spherical fine particle, and d0 is a diameter of the smallest particle that is necessary to do free flowing.In the case of irregular particles and mixing powders, the above relationship is approximately satisfied. However, according to the nozzle diameter becoming larger, the equilibrium velocity has a tendency to become unstable.7 Figs, 6 References.

Foundamental Studies on the Spray Drying and Semi-dry Press of Ceramics, (I) On the Spray drying of Clay Slips, (1)

Foundamental Studies on the Spray Drying and Semi-dry Press of Ceramics, (I) On the Spray drying of Clay Slips, (1)

De-airing of Casting Clay Slips and Gypsum Moulds for Potteries by Ultrasonics. (I)

The effects of ultrasonics on the de-airing of gypsum moulds in connection with physical and chemical behaviours, such as the setting time, mechanical strength, hardness, porosity, bulk density, abrasion, hydration and physical structure were studied.An apparatus, so-called magetostriction type, frequency 14KC/s and power 300 watts was specially designed by Prof. J. Saneyoshi. Calcined natural gypsum from Greek and “Nitto-gypsum” a special quality were used in this experiment.It was surprizing to find that air bubbles in a gypsum slurry had been eliminated sucsessfully under the action of ultrasonics during few seconds resulting markedly promotion of hydration and increase of mechanical strength, hardness and density of moulds. These results are shown in curves in Fig. 2 to Fig. 4. Microscopic observation indicates the distinct differences of crystal formation showing that more growth of smaller needle-like crystals shown in Fig. 5 and Fig. 6 in the case of a ultrasonic agitation rather than without agitation.In order to investigate the textures differences of moulds due to the physical and chemical corrosion, permeability of the specimens taken from every parts of wasted gypsum moulds has been measured.

Colloid Chemistry of Clay Drilling Fluids

It is only within the past 10 years that serious attempt appears to havebeen made to improve rotary drilling fluids by the application of theprinciples of colloid chemistry, although the use of chemicals to control therheological properties of clay slips has long been known in the ceramicindustry. The main difficulty apparently lay in the lack of a complete analysisof all of the functions of a drilling fluid in the drilling of the well, together with the lack of adequate consideration of how colloid science couldbe applied to secure these ends, and particularly how apparent antitheticalproperties of the fluid could be compromised. Thus one analysis1 of the manyrequirements of a drilling fluid proved conclusively that the viscosity shouldbe low, in order that cuttings and entrained gas might be eliminatedefficiently in the settling ditch, while the loss in carrying capacityaccompanying low viscosity could be regained by increasing either the densityof the mud or the upward velocity of the mud stream in the annular space of thewell, and the danger of sticking of the drill stem due to rapid settling incase of enforced suspension of drilling operations could be eliminated byenhancing the thixotropic properties of the fluid. The desired properties of the drilling fluid having thus been established, itwas a natural step to treat the fluid with viscosity-reducing chemicals, suchas salts of weak organic acids- for example, sodium tannate or gallate-and toadjust the pH to the alkaline side to such a degree of thixotropy as would give low viscosityand low yield point under the conditions of flow prevailing in the settlingditch, but rapid gelation and high yield point when quiescent in the annularspace during shutdowns. In fact, flow in the settling ditch should be justshort of turbulent while flow in the well, together with the flow of mud pastthe cuttings, is practically always turbulent. The use of chemicals other thanthose mentioned, such as Calgon (sodium hexametaphosphate) and certain otherphosphates together with sodium tannate, has now become standard practice andit is the consensus that this method of treatment has proved to be an importantstep in the development of the art of drilling oil wells. It is safe to assume that the application of colloid chemical principles canalso help in solving other outstanding problems of drilling fluids, such as thedevelopment of cheaper and more efficient viscosity reducers; the developmentof chemicals that do not lose their effectiveness in a short time duringdrilling operations; the finding of chemicals to preserve the plasteringproperties of muds when concentrated brines are encountered or in drillingthrough salt beds; improvement in the plastering properties of poor muds byfurther deflocculation, and, conversely, the prevention of excessivedeflocculation of certain marine shales sometimes encountered; the preparationof muds suitable for the successful drilling of heaving shale formations; thefinding of chemicals to treat the mud to prevent or to diminish lostcirculation; T.P. 1201

FUNDAMENTAL STUDY OF CLAY: II, MECHANISM OF DEFLOCCULATION IN THE CLAY‐WATER SYSTEM*

AbstractThe effect of bases, basic salts, neutral salts, acid salts, and acids on the viscosity of clay slips cleaned as described in Part I of this study is shown. From these data, a fundamental theory of deflocculation is built up, based on the fact that deflocculation requires the presence of OH anions and monovalent cations. The influence on the viscosity of small traces of soluble salts or adsorbed ions, which are present in commercial clays, is discussed. It is also shown why sodium silicate or carbonate works more satisfactorily than sodium hydroxide in the deflocculation of commercial casting slips.

CORRESPONDENCE. ENGINEERING PROBLEMS ASSOCIATED WITH CLAY, WITH SPECIAL REFERENCE TO CLAY SLIPS.

CORRESPONDENCE. ENGINEERING PROBLEMS ASSOCIATED WITH CLAY, WITH SPECIAL REFERENCE TO CLAY SLIPS.

ACID AND BASE BINDING CAPACITIES AND VISCOSITY RELATIONS IN CERTAIN WHITEWARE CLAYS *

In studying the relationships between the chemical and the physical behavior of clay slips, correlations otherwise obscured are brought out if the clay is first carefully purified. Electrodialysis seems to be an effective method of removing interfering adsorbed electrolyte from clay in preparing it for such investigations. Electrodialyzed samples of several whiteware clays in wide use in the ceramic industry were found to behave chemically as weak acids and bases. The amount of Na-OH necessary to neutralize the “acids” coincided with the smallest amount sufficient to produce the minimum viscosity in suspensions of these clays. The pH of exchange neutrality of each clay agreed closely with a maximum in its pH-viscosity curve. At this point, the addition either of HCl or NaOH reduced the viscosity, although not equally. As further amounts of NaOH were added, two effects were recognized. Some clays continued to become more fluid until complete deflocculation, while other clays passed first through a range of concentration in which NaOH caused increasing Viscosity. Changes in viscosity were observed also in suspensions with increasing concentrations of HCl. A theory for these effects is presented.

DISCUSSION. ENGINEERING PROBLEMS ASOCIATED WITH CLAY, WITH SPECIAL REFERENCE TO CLAY SLIPS.

DISCUSSION. ENGINEERING PROBLEMS ASOCIATED WITH CLAY, WITH SPECIAL REFERENCE TO CLAY SLIPS.

MECHANICS OF ENAMEL SUSPENSION, I Exchangeable Base and Viscosity Measurements on Some Vallendar Clays*

ABSTRACTThe results of viscosity measurements upon untreated and electrodialyzed Vallendar clay slips, using borax as an electrolyte in varying concentrations, are set forth and discussed. Several Vallendar clays have been analyzed for exchangeable base content and the results are given.

VACUUM TREATMENT OF CLAY SLIPS AND BODIES1

The work contained in this paper was conducted to determine the value of the treatment of clay slips to reduced pressures. Theoretical information obtained in references, however, indicate little possibility of there being much gas adsorbed by the solid particles of a porcelain slip. No improvement of dielectric strength or mechanical strength could be noted as a result of experimental work conducted.

HYDROGEN-ION CONCENTRATION AND ELECTRICAL CONDUCTIVITY OF CLAY SLIPS1.

The apparatus and method of determining the H-ion concentration and electrical conductivity of clay slips are described. Measurements were obtained on daily samples of tap water, casting and plastic slips, car shipments of clays, and individual blungers of slips in an endeavor to find whether any variations that might occur in the plant processes could be traced to variations in the slips indicated by these measurements. In a following paper values will be given showing the effect of temperature, time and vigor of stirring, specific gravity and concentration of various salts such as NaCI, Na2SO3, MgSO4 and AlCl3 on the H-ion concentration, viscosity, and electrical conductivity of slips.

STUDIES OF THE CHANGES IN THE VISCOSITY OF CLAY SLIPS AND GLAZE SUSPENSIONS ON AGING AND BY TREATMENT WITH ELECTROLYTES1

The rate and extent of the spontaneous thinning out of clay slips and glaze suspensions were measured; the effects of electrolytes on the viscosities of slips and glazes after aging until minimum viscosity was reached were investigated; measurements of the rate and extent of the spontaneous thinning of a glaze after treatment with electrolytes were made; and further experiments hearing on spontaneous thinning were conducted, such as heating the slip or glaze and the application of the colorimetric method in determining PH, etc.

HYDROGEN-ION MEASUREMENTS ON CLAY SLIPS1

A simple electrometric apparatus is described for determining the hydrogen-ion concentration of clay slips. Some measurements are given to show the relation between hydrogen-ion concentration and the properties of a clay and water mixture.

THE MEASUREMENT OF THE PLASTICITY OF CLAY SLIPS12

1The paper emphasizes the great need of a quantitative measure of the physical properties commonly included in the term “plasticity” of clays and clay slips. Various indirect methods previously suggested are likely to lead to erroneous conclusions, while measurement of the flow or apparent viscosity of clay slips made up with a constant amount of water is shown to give misleading results. 2The work described in this paper is preliminary in nature and has been confined to a study of the properties of clay-water mixtures in the casting rather than in the molding range. In the light of these results it is recommended that, instead of the vague term plasticity, the properties of a given clay, at least for casting purposes, be expressed in terms of (a) the water content required to give proper working consistency, and (b) the resistance of the resulting slip to small deforming forces (such as gravity). Specifically, use is made of a modified Bingham plastometer, and the figures reported are (a) the amount of water required to give a slip of a specified mobility, and (b) the yield value of the slip thus obtained. 3The method is shown to be capable of giving quantitative figures for the yield values at constant mobility which correspond well with the customary qualitative ideas as to the plasticity of clays. The amount of water required to give constant mobility varies to a surprising extent, and does not appear to bear any definite relationship to the usual classifications of more or less plastic clays. It probably does parallel fairly well the shrinkage on drying. 4Small amounts of acid or alkali are shown to have a negligible effect on the mobility of a clay slip, but a very large effect on the yield value, the variations being greater than the difference between a non-plastic kaolin and a highly plastic ball clay. This brings out the necessity, and indeed the potential value, of carefully controlling the hydrogen-ion content of the water used in making the slips. 5Some preliminary data are given on the effect of additions of flint and similar non-plastic materials to clay slips. 6It is recommended that an attempt be made to agree upon standard dimensions for the capillary and the desirable mobility for various purposes, and that the plastometer then be used as a standard method of test in the ceramic industry.

The Measurement of the Plasticity of Clay Slips

The Measurement of the Plasticity of Clay Slips

The origin of clay slips

The origin and geology of clay dikes (referred to as clay slips in this report) was discussed, based on data from the Bevier Seam, Boone County, Missouri. The clay dikes were found to be associated with thin coal along crests and adjacent slopes in the seam, but not with thick coal near the bottom of basins. The clay material entered fissures under pressure in an indurated form instead of as a plastic flow. The clay material itself was from overlying beds. Also included in the report was a section of back-calculating the dimensions of the original peat bogs from ratios existing between floor elevation and seam thickness.