Encapsulation and Solidification of Salt Bearing Evaporation Residues

Abstract

The feasibility of chemically bonded phosphate ceramic and polyethylene binder systems for encapsulation and solidification of salt-bearing evaporation residue is reported in this paper. Phosphate waste form with 50% waste loading was found to attain the average optimum compressive strength of7N/mm1 whereas polyethylene waste form could achieve 24N/m Leachability fraction of0.14 was attained by polyethylene at 1128h of immersion, while macro encapsulated phosphate leached by a fraction of 0.44 and uncoated phosphate waste forms leached by a fraction of 0.97. On immersion in water for 14d, uncoated phosphate waste form could maintain the compressive strength of 3.4N/mm= required for disposal in a landfill, whereas epoxy macro encapsulated waste form could maintain it till 49d of immersion. Phosphate solidification and macro encapsulation cost was Rs.124/ kg of evaporation residue and polyethylene micro encapsulation cost Rs.114/ kg.