Geochemical Assessment of Gypsum Scale Formation in the Hydrated Lime Neutralization Facility of the Daedeok Mine, South Korea

Scale is widely observed in the hydrated lime mine drainage treatment plant of Daedeok South Korea. In order to understand environment terms formation scale minerals, and water were collected from AMD facility analyzed. addition, saturation index was calculated based on geochemical modeling predict minerals that could be produced facility, results then compared with an analysis onsite minerals. Furthermore, neutralized pH 3 9 laboratory, precipitates identified. The changes Ca2+ SO42− concentrations also identified over time for each pH. predicted possible precipitation gypsum, anhydrite, bassanite after neutralization. Scanning electron microscope/energy dispersive X-ray spectroscopy (SEM/EDS) showed main mineral formed at by reaction during AMD. laboratory neutralization experiment gypsum all ranges 9, higher pH, greater amount produced. It demonstrated simulated amounts 2 g/L 7 5 well matched experimental results. Iron (Fe), a major pollutant system, rapidly precipitated form iron hydroxides As slowly continuously long period time, it growth throughout flow path. method minimizing production using lime, recommended should operated lowest possible, which will enable removal pollutants, such as aluminum.