From Lead Content in the Slags of Historic Mines to Silver Outputs

• In Event: 247. A New Perspective on Silver Flows in China and Southeast Asia, 15th to 19th Centuries

Abstract

Remains of historic silver mines have become a resource in the industrial period. High lead content in most slags as well as zinc and other metals in tailings encouraged re-exploitation as a lucrative venture at many sites. Geological prospecting reports and industrial records provide specific and unusually precise data on slag dumps, which occasionally also include other aspects of historic mining. The source is particularly valuable because it is a material remains, but they also pose unusual difficulties because they represent the end product of several processes and because they cannot be dated beyond the final end of large-scale mining, which was brought about by the mid-19th century civil wars.
This paper discusses approaches of reconstructing outputs on the basis of total slag volumes and their lead content. Based on the reconstruction of smelting processes, the lead content of the different types of the slags produced can be modeled. With a tool that permits assessing the number of process steps, the model reaches and estimate of the amount of ore that entered the process. As we have early nineteenth century data on minimal and lucrative silver contents in the ores, the reconstruction can attain at an estimate of the order of magnitude of total historic outputs.

Author

• Yuda Yang, Fudan University