Metal precipitation simulation from mine drainage using geochemical code

Abstract

Acid mine drainage containing heavy metals is usually generated in metal mines; it is generally neutralized using limes to precipitate those metals as hydroxides and carbonates. The neutralizing condition is determined by a rule of thumb. However, an elucidation of each chemical reaction in AMD could help to set more suitable treatment process: geochemical code such as PHREEQC is used to evaluate quantitatively these reactions. Furthermore, solid analysis such as XAFS of precipitates can also give an important geochemical data (e.g., formation condition and crystalline structure) of rare minerals. In this presentation, we show geochemical model of AMD treatment which was constructed by neutralizing test of various AMD samples and their future perspectives.