Glass ceramics and mineral materials for the immobilization of lead and cadmium

Waste management is one of the major global environmental issues. Incineration is an efficient treatment since it offers both a reduction of mass and volume and a possibility of energy recovery. One of the problems of incineration is the production of fly ash which is considered as hazardous waste with obligation of final disposal into a specific landfill. The objective of the present study is to investigate glass ceramics and sintered ceramics as new mineral materials for a sustainable immobilization and possible recycling of these incineration wastes. Toxic elements can be incorporated into crystals embedded in a glass matrix which has a function of the second barrier, or in highly resistant crystalline structure in a sintered ceramic. Based upon cations size considerations, this study is focused on Ca-rich or Ba-bearing minerals as possible hosts of lead and cadmium. Promising results have been obtained for CaMgSi2O6 diopside-bearing glass ceramics and sintered Ba1.5Mg1.5Ti6.5O16 hollandite, both in terms of toxic elements incorporation and of chemical resistance. (C) 2016 Elsevier Ltd and Techna Group S.r.l. All rights reserved.