Potential of reuse and environmental behavior of ochre-precipitates from passive mine treatment

Abstract

this work aims to characterize the waste sludge formed by neutralization in a passive mine water treatment system (Jales plant, Portugal). these waste materials were designated as ochre-precipitates, since they are mainly iron oxyhydroxide, specifically ferrihydrite, in accordance with the mineralogical study by X-ray diffraction. other properties, such as colour parameters in the colour space l*a*b*, thermal behaviour and metal content are presented. the obtained results help to evaluate the ochre potential for reuse as industrial pigments. they also give information about the toxic behaviour, in order to assist the waste management process of this passive system.