Abstract
In this study, metal recovery systems from pit waste water and sludge were examined in order to reduce the sludge produced by pit waste water treatment system of abandoned mine. The old Iwami mine located in Tottori prefecture was chosen as the study field.
The developed system that recovers metals from the waste water is composed of sulfidizing, oxidation and neutralization processes. The precipitate containing 53 % of Cu was first obtained through the sulfidizing process, then that containing 43 % of Fe was obtained through the oxidation process and finally that containing 22 % of Al was found through the neutralization process from the pit wastewater. The system recovering metals from sludge is also a three-step process composed of acid extraction, sulfidizing and neutralization. First, the precipitate which contains 33 % of Fe was obtained through the acid extraction process, then that containing 60 % of Cu was extracted through the sulfidizing process, and finally that containing 24 % of Al through neutralization process. Those recovered Cu and Fe by these systems can be used as a raw material for smelting.
