MINE WATER TREATMENT USING MAGNETITE AND IRON FERRITES

Iron ferrites and magnetite have been used for the removal of radioactive and heavy metals from liquid effluents. The mineral magnetite, or synthetically prepared iron ferrite (FeO•Fe2O3), is typically utilized. Iron ferrite can be employed for mine water treatment in a batch mode by adding preformed ferrite to the solution or by preparing the ferrite in situ, thus using the existing iron in the effluent. Natural magnetite can also be used in a batch mode, or better, in a column mode. In the presence of an external magnetic field, enhanced capacity was observed when using a column of supported magnetite for removal of actinides and heavy metals from wastewater. The enhanced capacity is thought to be primarily due to magnetic separation of colloidal and submicron particles along with some complex and ion exchange sorption mechanisms. The loaded magnetite can easily be regenerated by removing the magnetic field and using a regenerating solution. This paper briefly reviews previous work on the use of iron oxides for wastewater treatment and presents new results on using magnetite and iron ferrites for the effective treatment of several different mine waters and for valuable metal recovery. 1