Fundamental Studies on Sinyewon Clays

新禮院粘土에 관한 基礎的 硏究

Four kinds of clays from Sinyewon mine which is located in Chungchoungnam-Do district and two kinds of Japanese clays (Gairome, Kibushi) were selected and studied on the fundamental properties of these clays and those which are refined by the elutriation method. Chemical analysis, grading analysis such as refractoriness, specific gravity, color, fired color and plasticity, particle size distribution, various thermal tests, X-ray diffraction analysis and electron microscopic survey were carried out on these clays. The comparison of domestic clays with Japanese clays was made. 1. In chemical composition and physical properties, these four kinds of Sinyewon clays are almost similar to each other and also to Gairome and Kibushi clays. In refractoriness, Gairome and Kibushi clays have relatively high value such as SK 34 and 35, while Sinyewon clays have the value of about SK 32. Especially Sinyewon clay B has the low refractoriness (SK 18) and plasticity. Refined clays have the tendency of somewhat higher value than crude ones in refractoriness. 2. When burnt up to $900^{\circ}C$, the coefficients of contraction of Sinyewon clays were under 1.5%, Gairome under 1.3%, Kibushi under 3.0%. Only Sinyewon clay B showed expansion (1.0%) instead of contraction. 3. X-ray diffraction analysis and electron micrography showed that all of four Sinyewon clays and two Japanese clays are mainly composed of poorly crystallized kaolin, containing small amount of halloysite, sericite and considerable amount of quartz and feldspar. Sinyewon clay B contains especially large amount of quartz and feldspar. In general, it has been found out that the refined clays were free from large amount of iron oxide, quartz and feldspar.