Saturation and sedimentation evaluation in the selective precipitation acid mine drainage

Abstract

In the present investigation, we carried out the evaluation of the saturation and sedimentation in the selective precipitation of acid mine drainage. Heavy metals were copper, zinc, manganese, iron and aluminum, the precipitation was performed by ad. calcium dioxide, establishing an appropriate range of pH based on the diagram of precipitation. The evaluation was performed with discontinuosm batch tests consisteing in order to establish the necessary parameters for sizing a continuous clarifier. The selective precipitation of the heavy metals present in the acid mine drainage is possible within the following ranges: at pH 4.15 the highest recovery is for iron with a value of 99.6% and 98.2 as established composition . At pH 5.9 a greater copper recovery is achieved with a composition of 88.5 and 73.6. At pH 8 the highest recovery is for zinc at of 94.6% and a composition of 81.4%. At pH 10 the higheest
recovery corresponds to 64.5 % manganese and a composition of 95.6%. Through this discontinuous sedimentation study it is possible determining the necessary design parameters for a continuous sedimentator in the selective precipitation of heavy metals from acid mine drainage.