Preliminary study on zinc smelting relics from the Linjiangerdui site in Zhongxian County, Chongqing City, southwest China

Abstract

The study of zinc distillation technology in ancient China has recently been published by Zhou et al. 2012, 2014. From these two papers we know more detail informations about it. But, there are still some key technologies we do not know exactly. The first question is if there is any difference between the coal used as fuel or as reductant agent? We also don't know the exact smelting temperature in this kind of smelting activity. The last and most important thing, we know that the retorts were charged with zinc ores, coal and charcoal, but we know little about the exact ration between them. In order to solve these questions, this paper presents the analytical study by OM, XRF, XRD, DIL and SEM-EDS of zinc production that remains from the archaeological site of Lijiangerdui, in the same region, dated to the Ming dynasty, probably a few years earlier than the previous studies. The results indicated that there are different coals used for the smelting activity, and the smelting temperature can be as high as 1306°C, all of these are over 1180°C. The ratios for the raw material may be 1:2.7 [(coal+charcoal)/zinc ores].