THEORETICAL AND EXPERIMENTAL-STUDY OF METAL CAPTURE DURING INCINERATION PROCESS

Experimental studies and thermodynamic equilibrium analysis were carri ed out to investigate the effects of operating conditions and input wa ste compositions on the adsorption of heavy metals (Cr, Pb, Zn, and Cd ) on silica sand during incinceration processes. The experiments were performed with a pilot-scale fluidized bed incinerator, and the evalua ted parameters include (1) sand bed temperature (500, 700, and 900 deg rees C); and (2) the addition of organic chloride (PVC), inorganic chl orides (NaCl and CaCl2), and sulfide (Na2S). The experimental and simu lating results indicated that the addition of organic chloride (PVC) w ould increase the formation of volatile metallic chlorides, and decrea se the adsorption efficiency of silica sand. On the other hand, the ad dition of inorganic chlorides (NaCl and CaCl2) worked differently, whi ch increased the adsorption efficiency of silica sand. The addition of sulfide (Na2S) would increase the adsorption efficiencies of the four metals in silica sand because sulfide inhibited the formation of meta llic chlorides. The hexavalent chromium content in the sand bed decrea sed for the addition of organic chloride (PVC), and increased for the addition of inorganic chlorides (NaCl and CaCl2).