This paper investigated the effectiveness of (ground granulated blast furnace slag) GGBFS-added chemically bonded phosphate ceramic (CBPQ 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 H902-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 Hg2+ from GGBFS-added CBPC matrix could be reduced from 697 lig/L to about 3 Lg/L when treating HgCli. Meanwhile, the main hydrating product of GGBFS-added matrices was still MgKP04.6H,O. The improvement of S/S effectiveness was mainly due to physical filling of fine GGBFS particles and microencapsulation of chemical cementing gel. (c) 2008 Elsevier B.V. All rights reserved.