Characteristics of neutralized mine drainage sediment depending to the depth in semi-active treatment

In the semi-active treatment process of mine drainage, neutralized mine drainage flows into settling pond to form sedimentary layer. The sedimentation layer is increased in thickness over time by the continuous inflow of sediment, and the bottom  of the sediment layer is compressed by the load of the upper layer. Thus, the physical characteristics of the sedimentary layers change depending on the depth over time. In this study, the sedimentation layers of four semi-active treatment facilities in South Korea were sampled by depth to measure physical properties and chemical composition. As a result of the analysis, the density and water content of the sludge did not change significantly, while the particle size distribution and viscosity were different according to the depth. As a result of statistical analysis, there was a significant correlation between depth, water content, and viscosity of the sediments. In addition, the content of Mn and Fe contained in the sediments was correlated with the content of Ca and Mg.