Multivariate and Spatial Analysis of Heavy Metal Sources and Variations in a Large Old Antimony Mine

Since the advent of the industrial revolution, soils around the world have been found to have elevated levels of various heavy metals. In China, the mining and smelting of Pb (lead), Zn (Zinc), Cu (copper), Sb (antimony) and Au (gold) ores are the major sources of heavy metal contamination of the soils in the local areas around the mines.

China has the largest reserves and highest annual production of Sb in the world, and in an old Sb mine in Xikuangshan (XKS), the mining and smelting of Sb have resulted in contamination with various heavy metals. However, the spatial variations in various heavy metals relative to the sources and transportation of Sb have rarely been documented.

To resolve this problem, FU Shuai and WEI Chaoyang conducted a survey in an old Sb mine in XKS to investigate the similarities and differences among the sources and diffusion characteristics of the heavy metals that were present as well as the factors influencing these patterns.

The result showed that Hg and Cd were evidently elevated in XKS, whereas the concentrations of As, Pb and Zn were moderate and that of Cr was comparable to the background values. Moderate correlations were found for Sb–As and Hg–Cd, and strong correlations were observed for Pb, Zn, Cd and Cr. The southeast direction was associated with the strongest spatial autocorrelation for Sb, which is consistent with the prevailing wind direction in XKS. The optimal directions for Zn and Cd were similar and indicated the transfer of Zn and Cd contamination from subareas with high levels to those with low levels, significantly affecting the spatial distribution of these metals in XKS.

This study highlights the importance of the effect of wind on the diffusion of Sb in XKS. The co-contamination of Hg and Cd with Sb is widespread in XKS due to the presence of Hg and Cd in Sb-containing ores. The result was published in Journal of Soils and Sediments in January 2013, 13(1): 106–116.