Incineration fly ash is a kind of hazardous solid waste containing many soluble substances such as chlorides,it limits its application.As one of the most effective pre-treatment methods,water washing can effectively reduce the content of chlorine,sodium,potassium and other components in fly ash,and increase the amount of fly ash added in cement raw materials.This paper collected three grades of washed fly ash from the washing line to study its feasibility.The results showed that multiple washing can effectively remove chloride ions.The three types of washed fly ash could promote cement grinding at low dosing,shorten setting time,and reduce energy consumption with the same washing fineness.At a dosing rate of lower than 10%,it did not shorten the setting time of cement and could improve the compressive strength of cement at different ages.The heavy metal leaching at a 20%dosing rate satisfied the GB 5085.3-2007.Incineration of fly ash as blending material reduced the exothermic heat of hydration of the cement and generated new mineral-Friedel salts.If the limitation of each ion in the incineration fly ash after water washing is considered,the maximum admixture was lower than 1.58%.Therefore,washed incineration fly ash has the potential to be used as cement blending material.And its resource recovery capacity can be increased by removing the chloride ions and other factors.
water washed incineration fly ashmixed materialsheavy metal leachingrecycling
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