This study aimed to obtain fundamental data for developing efficient recovery process of valuable metals from various molten fly ashes produced from melting furnaces. Release behavior and chemical form change of zinc were investigated during chlorination of ashes. Chemical forms of zinc in ash were classified into four groups, oxide and carbonate, silicate and aluminosilicate, ferrite, and sulfide by chemical leaching and XRD analyses. In molten fly ash M and B produced from coke bed and fluidized bed-gasification melting furnaces, 93% and 60% of zinc existed in the form of oxide or carbonate, respectively. Ash B contained ferrite, silicate, aluminosilicate, and sulfide as the remainder. A drastic change of zinc form distribution was observed for ash B after heat treatment at 1073 K, while zinc was hardly released from the solid phase of ashes M and B. When the ashes were heated with polyvinyl chloride, zinc oxide and aluminosilicate reacted to give a volatile compound. Zinc ferrite reacted with calcium carbonate and was stabilized into the solid phase as zinc oxide. Carbon addition was effective for volatilization of all zinc forms, including zinc silicate and zinc sulfide.