Experimental Study On Preparation Of Sulphoalmuinate Cement From Mswi Fly Ash

The municipal solid waste incineration (MSWI) fly ash has been classified as the hazardous waste because of its heavy metal and dioxin contents. However, more and more stringent measures for special waste landfill and the scarcity of safety landfill sites have encouraged the recycle and reuse of MSWI fly ash. Sulphoalmuinate cement is one kind of abio-nonmetal material. It has excellent capabilities,extensive using and high addictive value. So produce sulphoalmuinate cement with MSWI fly ash is feasible. This approach not only can make full use of MSWI fly ash, but also can reduce the production cost. However, high content of heavy metals and chlorides in fly ash can pose technical problems when used in cement production. Measures must be taken to prevent these problems by performing a pre-treatment of fly ash in order to remove heavy metals and chloride.This thesis analyzes the elements composition characteristics in fly ash, and then study the effect of the pre-treatment of carbonation and washing. Discussing the liquid-solid ratio, carbonation reacting time and washing influence on the leaching characteristics of heavy metals. The pre-treatment sample has been burdened for the sulphoalmuinate cement preparation in lab.Through X-ray diffraction and scanning electric analysis of clinker and hydration product, we study the forming and hydrating of the sulphoalmuinate cement minerals. Discusses the influence from the calcination mechanism, fly ash pre-treatment and gypsum addition on the performance of the cement, and analyses the environmental safety property. The study indicates that it is feasible to utilize fly ash to produce sulphoalmuinate cement. And it provides a theoretical basis for the sulphoalmuinate cement preparation from MSWI fly ash.