Improvement of ground granulated blast furnace slag on stabilization/solidification of simulated mercury-doped wastes in chemically bonded phosphate ceramics

Abstract

This paper investigated the effectiveness of (ground granulated blast furnace slag) GGBFS-added chemically bonded phosphate ceramic (CBPC) matrix on the stabilization/solidification (S/S) of mercury chloride and simulated mercury-bearing light bulbs (SMLB). The results showed that the maximal compressive strength was achieved when 15% and 10% ground GGBFS was added for HgCl 2-doped and SMLB-doped CBPC matrices, respectively. The S/S performances of GGBFS-added matrices were significantly better than non-additive matrices. As pore size was reduced, the leaching concentration of Hg 2+ from GGBFS-added CBPC matrix could be reduced from 697 μg/L to about 3 μg/L when treating HgCl 2. Meanwhile, the main hydrating product of GGBFS-added matrices was still MgKPO 4·6H 2O. The improvement of S/S effectiveness was mainly due to physical filling of fine GGBFS particles and microencapsulation of chemical cementing gel.