Research On Smelting Technology Of Lead And Silver Sites In Southwestern Yunnan In Ming And Qing Dynasties

Most of the academic research on ancient lead and silver smelting technology has focused on the interpretation of ancient literature,while less research has been conducted on the analysis of smelting slag distributed at lead and silver sites,and no scholars have yet conducted relevant research and analysis on lead and silver smelting waste in southwest Yunnan.Therefore,this study plays a role in promoting ancient lead-silver smelting technology and even ancient leadsilver smelting technology in southwest Yunnan.The sites of Shiyang Factory in Shuangbai County,Chuxiong Yi Autonomous Prefecture,Mengnuo Site and Yangmei Factory in Longling County,Baoshan City,Mingguang Sixth Factory in Mingguang Town,Tengchong City,Baoshan,Changhe in Mangshi City,Dehong Yingjiang County,and Mao Long Factory in Banhong Township,Cangyuan City,Lincang City,all date back to the Ming and Qing dynasties.In this study,preliminary analysis and examination of slag collected from seven smelting sites in southwestern Yunnan Province using literature survey,field investigation,and experimental analysis(mainly scanning electron microscopy)revealed preliminary results of lead and silver production at these sites.The results show that the Mengnuo site in Longling County and the Mingguang Sixth Factory site in Mingguang Township used lead smelting furnaces,added charcoal and calcium slagging agent,and smelted silver-bearing Pb-Zn ore by the roasting-reduction smelting method,and the smelting products were considered to be silver-bearing Pb ingots and slag;the Shiyang Factory site in Shuangbai County,the Yangmei Factory site in Longling County,the Liuhong Factory site in Yingjiang County,and the Maolong Factory site in Cangyuan County used silversplitting furnaces,used charcoal as fuel,and oxidation-blown silver-bearing Lead ingots,smelting products are considered pure silver and lead oxide slag.The silicic acidity,alkalinity,and density of the slag basically meet the requirements of modern metallurgical theory for the physicochemical properties of the slag.According to the ancient records and field investigations,the site of Mangshi Changhe is generally considered to be a lead-silver site,but the experimental results show that the site is a copper smelting site,and it is presumed that there is a possibility of using the lead-silver site for copper smelting.By combing the silver factory system in western Yunnan,it was found that the silver factories in southwestern Yunnan during the Ming and Qing dynasties already had a modern organization and management,with a clear division of labor and each having its own duties.This study also used the measurement data of two smelting furnaces of Shiyang factory as the basis for three-dimensional modeling and hydrodynamic simulation,and the simulation results showed that the honeycomb furnace of Shiyang factory had the possibility of using natural air blowing.Due to the limited material,the specific silver extraction methods of several sites covered in this study have to be studied and explored in detail by further archaeological discoveries.