重庆忠县洞天堡墓地出土西汉青铜钫的腐蚀研究

Study of the corrosion of a Western Han bronze Fang unearthed at Dongtianpu Cemetery of Zhongxian County,Chongqing

为了解重庆洞天堡墓地出土青铜器的保存状况、腐蚀产物种类和埋藏环境特征等,并探索其锈蚀成因,为即将进行的保护修复工作提供科学的依据,利用三维视频显微镜、激光共聚焦拉曼光谱仪和扫描电子显微镜等对重庆忠县洞天堡墓地出土青铜钫残片进行微观形貌观察和锈蚀物结构成分分析,并利用X射线荧光和微生物分析技术对青铜钫附着土壤进行成分和微生物分析。结果表明:该青铜钫锈蚀物含孔雀石、白铅矿、铅钒、磷氯铅矿、砷铅矿和赤铜矿等;外层锈蚀存在磷和氯元素富集现象;土壤中的磷、硫和氯等元素向青铜器迁移,青铜器中铜、锡和铅元素因腐蚀向土壤中流失;附着土富含多种真菌类微生物,促进了磷氯铅矿和砷铅矿的形成。

In our study,we analyzed the structure and composition of corrosion products of a bronze Fang sample(dated to the Western Han Dynasty)unearthed at Dongtianpu Cemetery of Zhongxian County,Chongqing,using optical microscopy(OM),scanning electron microscopy(SEM)and Raman spectrometry.The composition and microbial community of the buried soil attached to the Fang were also analyzed using X-ray fluorescence(XRF)spectrometry and microbiological analysis technology.The results show that 1)the main corrosion products include malachite,cerussite,anglesite,pyromorphite,mimetite and cuprite;2)the enrichment of phosphorus and chlorine can be seen obviously in the outermost corrosion layers;3)phosphorus,sulfur and chlorine from the soil were found enriched on the bronze Fang,and copper,tin and lead of the bronze Fang diffused to the soil and 4)fungi such as Trichocomeceae,Penicillium and Aspergillus were detected in the soil attached to the bronze Fang.