Journal of the American Ceramic Society

doi: 10.1111/j.1151-2916.1931.tb16925.xpmid: N/A

doi: 10.1111/j.1151-2916.1931.tb16926.xpmid: N/A

doi: 10.1111/j.1151-2916.1931.tb16927.xpmid: N/A

doi: 10.1111/j.1151-2916.1931.tb16928.xpmid: N/A

doi: 10.1111/j.1151-2916.1931.tb16929.xpmid: N/A

Norton, F. H.; Hodgdon, F. B.

doi: 10.1111/j.1151-2916.1931.tb16930.xpmid: N/A

ABSTRACT In this investigation quantitative relations have been established between the time and temperature effects in the maturing of whiteware bodies. Six typical commercial whiteware bodies were used. Similar shrinkage and porosity curves were obtained for different firing times but the longer the time the lower the curve was shifted on the temperature scale. It was found that in all cases the usual logarithmic law relating temperature with the rate of reaction applied. The constant, however, was not the same for all bodies. The microstructure of these bodies will be dealt with in Part II of this paper.

Norton, Charles L.

doi: 10.1111/j.1151-2916.1931.tb16931.xpmid: N/A

ABSTRACT This investigation deals with the microscopic examination of three of the whiteware bodies which were described in Part I of this paper. With respect to the influence of time of firing upon the crystalline texture, it was found that with samples which showed the same degree of maturity by physical test, the long‐fired, low‐temperature samples showed more quartz solution as well as more mullite development than the samples fired more quickly at higher temperatures.

Holscher, H. H.

doi: 10.1111/j.1151-2916.1931.tb16932.xpmid: N/A

ABSTRACT It has been found that porous ceramic bodies increase in volume and weight due to an autoclave treatment in which the ware is subjected to steam at a pressure of 150 pounds per square inch. The change is rapid at first but decreases as the time of treatment is increased. Typical American and English china clays also increase in volume but ball clays when fired to the same temperature as the china clays do not increase in volume. The effect of prolonged drying treatments after the autoclave treatment is also studied. Data given indicate that the changes in volume are not necessarily caused by rehydration of the clay within the body. Bodies containing clay, feldspar, and flint show a greater increase in volume than do the pure clay constituents. It is shown that the composition is a more important factor than absorption in determining the reaction of ceramic products to the autoclave treatments.

Curtis, Carl E.

doi: 10.1111/j.1151-2916.1931.tb16933.xpmid: N/A

ABSTRACT The history of the developments by Count Schwerin, application at Carlsbad with detailed description of the plant, and review of the investigations of others on dewatering of clays by electrophoresis, are given at length. The investigations by the author, including a description of the apparatus, materials, voltage, and electrolytes are described with a statement of the results obtained with variations of each factor. The possible efficiency as a clay dewatering means is discussed. Plasticity theories are discussed in the light of the evidence obtained. The power cost is from 65 to 80 cents per ton of clay. On the average, clay dewatering by electrophoresis is no more efficient than the filter‐press, but it has shown greater efficiency on very fine‐grained clays. Bibliographies are appended on (1) colloids in clays, (2) theories applying to electro‐endosmosis, (3) electromosis, and (4) Schwerin's patents. A short biographical sketch of Count Schwerin is also appended.