Method for determining required amount of chelating-based heavy metal fixing agent and method and apparatus for determining heavy metal fixing effect of treated ash

摘要

PROBLEM TO BE SOLVED: To easily and accurately determine the proper addition amt. of a chelating agent to ash containing heavy metals to prevent elusion of heavy metals, and to easily and accurately judge the effect to fix heavy metals in the ash which is treated to prevent elusion of heavy metals by adding a chelating agent to the ash containing heavy metals. SOLUTION: A chelating agent is added to a water slurry of ash containing heavy metals to measure the ORP. The amt. of the chelating agent added till decrease in the ORP is terminated is obtd., and the proper addition amt. of the chelating agent is determined from the measured amt. The effect to fix heavy metals in the treated ash is judged from the results of measuring the changes in the ORP when the chelating agent is added to the water slurry of the treated ash and by comparing the measured changes to the predetermined values.