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PURPOSE : To provide a preparation method of fixing agent for heavy metals contained in waste fly ash and the fixing agent prepared by the method, wherein the fixing agent is capable of suppressing re-elution of heavy metals, preventing secondary environmental pollution and minimizing both economical burden and discharge quantity of final wastes.
CONSTITUTION : In a method for preparing a fixing agent stably collecting and fixing various harmful heavy metals contained in fly ash generated in a process of incinerating varieties of wastes, a preparation method of the fixing agent for heavy metals contained in waste fly ash comprises : a process(S10) of obtaining first mixture by uniformly mixing 5 to 15 wt.% of potassium tetrasulfide with 65 to 75 wt.% of water for 50 minutes to 1 hour using an agitator; a process(S20) of obtaining second mixture by uniformly mixing the first mixture obtained by the process(S10) with 5 to 15 wt.% of potassium pentasulfide for 50 minutes to 1 hour by using the agitator; a process(S30) of obtaining third mixture by uniformly mixing the second mixture obtained by the process(S20) with 5 to 15 wt.% of dithiocarbamate derivative for 3 to 5 hours by using the agitator; a process(S40) of obtaining the fixing agent by passing the cooled mixture through a filter such that impurities are removed from the mixture after cooling the third mixture obtained by the process(S30) at an ordinary temperature; and a process(S50) of inspecting.
© KIPO 2006