Mercury distribution analyses and estimation of recoverable mercury amount from byproducts in primary metal production facilities using UNEP toolkit and on-site measurement

Mass distribution of mercury (Hg) and estimation of recoverable Hg amount from primary metal production facilities (zinc, lead and copper) were investigated. According to UNEP Toolkit Level 2 for figuring out the contribution of Hg release from major source categories, the primary metal production industry was estimated as a main Hg source among whole industries in South Korea, which was accounted as a half of the total inflow and the amount was 178 ton-Hg/year. Four kinds of domestic primary metal production facilities (zinc, zinc and lead and copper smelters) were selected for conducting on-site measurements for mass distribution analysis of Hg. The total amount of Hg released into different phase media was estimated only as 20.68 ton-Hg/year on average. The highest share of Hg released was from zinc and lead production facilities as the same as seen in UNEP toolkit. However, the difference in the release amount of Hg between UNEP Toolkit and on-site measurement was found from large differences of Hg content data in input raw materials. Also, 18.21 ton-Hg/year was released as solid-phase byproducts such as wastewater sludge and slag, which are recoverable. The amount of Hg recoverable from zinc and lead production facility was estimated as 16.0 ton-Hg/year on average.