Recycling of water quenched slag and silica sand tailing for the synthesis of an eco-friendly permeable material

This research used the water quenched slag (WQS) and silica sand tailing (SST) to prepare a novel WQS-SST based permeable material (WSPM) by traditional sintering method. Effects of WQS/SST mass ratio and sinter-ing temperature on the structure and properties of the WSPM were discussed. The XRD and SEM-EDS results show that the combination of the WQS and SST can form the glass liquid phase (GLP) which is CaO-Fe2O3-SiO2 glass as main composition accompanying with small amount of Al2O3 and one or more trace amounts of Na2O/ K2O/MgO, and promote the synthesis of the WSPM. Both the WQS/SST mass ratio and sintering temperature can affect the formation of the GLP, which further alter the structure and properties of the WSPM. Under the opti-mum condition (WQS/SST = 2/8, 1200 degrees C/1h), the prepared WSPM shows the best engineering properties, including the high permeability of 2.03 x 10-2 cm/s and the considerable compressive strength of 26.83 MPa. Meanwhile, the WSPM with the optimum condition shows stable immobilization behavior for the heavy-metal ions of Zn, Mn, and Cr in the ICP test. It indicates that the WSPM in our work is an eco-friendly all-solid -waste based permeable material, which has great application value in the field of permeable bricks for sidewalk construction.