Research on operationg conditions of fabric filters to minimize an emission of unintentionally produced POPs from aluminum alloy smelting plants was conducted. A small experimental fabric filter installed in a tentative flue gas line from a recycled aluminum smelting furnace was used instead of the actual operating filter. The results shows that more than 90 % removal efficiency of dioxins by using the fabric filter requires as low as 75C of the temperature of filter surface for the aluminum smelting plants. It means dioxin formation in the fabric filter could not be ignored below 100 C although it is known to be negligible less than 200 C in the case of waste incinerators flue gas. Injection of NaOH solution in an upper stream of the filter is quite effective for dioxin reduction and not so far for PCBs and HCBz. However, injection of activated carbon is effective enough in reduction of PCBs and HCB and not so far of dioxins. The reason of same operation exerts different effects on reduction of PCBs and HCB by fabric filters from dioxins, is attributed to the difference of their formation mechanisms.
