Demcthyl ketoxime is a strong reducing agent

which can form a better passive film than hydrazine.Through the passivation test and dynamic test in laboratory the technological conditions of passivation by demethyl ketoxime are determined. and they have ben succesfully applied in passivation of a acid - cleaned domestic 1025t/h subcritical boiler. The technological conditions for passivation by demothyl ketoxime are as follows: Concentration of demethyl Ketoxime 500mg/l; pH-5～10.0;total iron no more than 300mg/l; duration time-16～24 hours;temperature-80℃-90℃.The technology of waste treatment after demethyl ketoxime passivation is quite simple and has no environmental deterioration.