Formation of CaCl2 and CaF2 from CaSO4 and Plastics Containing Halogen Element
Shigeru Ueda, Yuuki Hatakeyama, Koji Uotani, Katsunori Yamaguchi, Takahiko Okura
Waste gypsum from construction materials have to be recycled legally in Japan.
Combustion of plastics containing halogen may generate halide gas. Stabilization treatment of halogen element should be done. In the present study, the reaction between the plastics and gypsum generating calcium halide such as CaCl2 or CaF2 had been investigated. Reaction condition was evaluated thermodynamically, and experiment for generating CaCl2 and CaF2 was conducted. CaCl2 was formed from CaSO4 and chloroethylene at 1273K. CaF2 was formed over 1173K. Crystal water of CaSO4 accelerates the reaction forming CaF2.