Abstract
Goeido was restored from 1998 to 2009 at the Nishi-Honganji in Kyoto. Lots of iron slag, iron lump and tuyere were excavated from the precinct of Nishi-Honganji, when a construction of disaster prevention was done in autumn of 2006. These iron slag was investigated by metallurgical analysis of some scientific methods. Metallurgical structures in the iron slag were observed by an optical microscope and an electron probe micro analyzer (EPMA). Chemical compounds in the iron slag were identified by a X-ray diffraction method. From these analytical results, Fayalite (Fe2SiO4) and Wustite (FeO) being principal chemical compounds in the iron slag were observed in all samples. Especially, Wustite is characteristic chemical compound produced from a smithing process. Therefore, it was founded that these iron slag was disposed after the smithing. Moreover, multielements in the iron slag and iron lump were determined by a neutron activation analysis (INAA). Especially, the ratio of arsenic concentration to antimony concentration in the iron is able to use as an indicator for estimation the place of production of the raw materials used to make the iron. The ratio in the iron lump and the ratio in previously analyzed iron nails for roofing tiles or for Urakou were almost the same. Therefore, the place of production of the raw material as iron sand from Oku-izumo area in Shimane.
As these results, it was founded that a large amount of iron crude materials were carried from Oku-izumo to the precinct of Nishi-Honganji, and these were processed for iron nails by the smithing.
