충주 칠금동 유적 출토 노벽의 자연과학적 분석 = Scientific Analysis of Furnace Wall Samples Excavated from the Chilgeum-dong Site, Chungju

다국어 초록 (Multilingual Abstract)

This study explored ancient iron-smelting technologies and operational conditions by analyzing the physicochemical properties of furnace wall samples excavated from the Chilgeum-dong archaeological site in Chungju. Samples from Furnaces 2, 17, and 19 were subjected to a suite of scientific analyses, including cross-sectional observation, XRD, XRF and ICP-MS. The results revealed broadly similar mineralogical and chemical compositions among the samples. However, notable differences in thermal exposure temperature were identified based on stratigraphic position and orientation. High-temperature phases like mullite and cristobalite, identified by XRD in the inner fired layers, indicated that the furnace walls experienced exposure to temperatures exceeding approximately 1200°C~1300°C. In contrast, the outer, unfired layers were characterized by the thermal decomposition of kaolinite and absence of high-temperature minerals, suggesting exposure to lower temperatures in the range of 550°C~800°C. Notably, samples from Furnace 17—where directional sampling was possible—exhibited higher degrees of thermal alteration near the tuyere zone, alongside localized signs of heat-induced deformation and repair. The statistical evaluation of major and trace element concentrations demonstrated a strong compositional similarity between Furnaces 17 and 19, whereas 2 showed significant divergence, likely reflecting differences in raw material selection, construction period, or production conditions.