The Study on Material Characteristics of the By-Products of the Production of Bronze during the Goryeo Dynasty Excavated from the Sinpung Site, Wanju, Jeollabuk-do, South Korea

Abstract

This study interpreted the characteristics of the site and provenance of raw material by performing material characteristics analysis of the slags and tuyeres excavated from the Sinpung site in Wanju, Jeollabuk-do. The major chemical compositions suggested that the slags and tuyeres were created when Cu-Sn-Pb was alloyed. Metal microscope and scanning electron microscopy-energy dispersive spectrometer analyses revealed that the slags and tuyeres were by-products formed in the alloying process. This alloy, created by adding galena to copper and tin ingots, was an intermediary material used in making the finished products. According to the lead isotope ratio analysis result, slags could be made using galena of the southern Zone III region of Korea. Based on the decomposition of mica group minerals and the formation of mullite detected through X-ray diffraction analysis, it is possible to conclude that the tuyeres operated at approximately 1,000℃ as, the mullite was detected on the outside of the tuyeres.

Chemical Composition, Crystal Structure, and Microstructure of Slags on the Korean Peninsula from the First Copper Production Remains of the 9th Century

“…The Wanju Sinpung sites [3] were confirmed to be slags generated during the alloying stage, while the Wanju Ungyo remains were identified as smelting slags with relatively effective calcination.…”

“…The remains from Buyeo Neungsan-ri consisted of four bronze lumps, analyzed as two crude coppers from smelting matte, one Cu-Sn bronze alloy produced by adding tin to refined copper, and one Cu-Sn-Pb bronze alloy created by adding tin and lead to refined copper. The Wanju Sinpung sites [3] were confirmed to be slags generated during the alloying stage, while the Wanju Ungyo remains were identified as smelting slags with relatively effective calcination.…”

“…Copper production remains that have been found so far in the Korean Peninsula include the Gyeongju Hwangnam-dong 376 site of the mid-6th century [17], Buyeo Neungsanri temple site of the 6th century [18], Gyeongju Dongcheon-dong site of the 7th-to-8th centuries [7,19], Gyeongju Noseo-dong site of the 7th-to-10th centuries [20], Naju Bokam-ri site of the 7th century [21], Buyeo Ssangbuk-ri site of the 7th century [22], Buyeo Gwanbuk-ri site of the 6th-to-7th centuries [8], Wanju Ungyo site of the 4th-to-7th centuries [23], and Wanju Sinpung site of the 10th-to-14th centuries [24].…”

“…Since metals are prone to corrosion, reconstructing the historical development of metal culture from excavated metal artifacts poses challenges. However, insights can be gained through the analysis of slags produced during smelting and artifact fabrication [3]. Generally, slags are composed of oxides such as SiO 2 and Al 2 O 3 , and their composition varies depending on the purpose and methods of smelting.…”