Technical Analysis of Ironmaking in Benxi Region During the Ming Dynasty

During the development of metallurgical technology in the feudal period, the main ironmaking technology in the Benxi region was the crucible, reaching its peak period in the Ming Dynasty. By studying the Wangguan ironmaking site in Benxi, the historical details of the Ming Dynasty ironmaking process in the region were investigated, and a technical analysis was carried out. The results show that this historical site was the location of the Hundred-Household Iron Yard in the northeastern region during the Ming Dynasty. The unearthed slag, iron, and crucible samples indicate that a relatively complete ironmaking process chain had been formed at this time. The raw material used for the crucibles was high-alumina clay, which has been widely distributed in Benxi, Liaoning, China, since ancient times. The refractoriness of the crucibles exceeded 1700 °C, and the molar ratio of SiO2 to Al2O3 was close to the upper limit for the optimal formation of mullite and thermal shock resistance. Slag was produced from a typical high-silica, high-alumina aluminosilicate system, and no fluxes, such as limestone and dolomite, were added during the smelting process. Moreover, coal resources have been widely used in ironmaking activities in the Benxi region at least since the Ming Dynasty, and craftsmen at that time had already mastered the technology of using coke as fuel and reductant to control the sulfur content in pig iron.