Research On Lixiviation And Solidified Mechanism Of Heavy Metals In Cement And Concrete

Based on the analysis of the actuality and the target in future of the wastedisposal, this paper adopted three kinds of cement clinker system .And analyzed theimpact of the quantity of waste ,the causticity solution and the pore structure on thelixiviation of heavey metals.Using XRD,EPMA,SEM and NMR to determine thecomposition of hydrated production, the distribution of heavy metals, through whichsolidified mechanism is discussed in detail.Accoring to two studies above, thefeasibility of using cement kiln to deal with hazardous waste and produce cementwas evaluated externally.Which not only realized entironment but also exploited annew way to deal with hazardous waste. In this paper , the conclusion showed that more 99%heavy metals could besolidified in concrete by means of denseness,physical pack, adsorption and chemicalcombination.The heavy meatal of Pb,Zn and Ni were adsorbed on surface of thecement grains by means of compounds in the course of hydrating.Cr participated inhydrating reaction and formed new compounds,which was similar with Afm instructure.The heavy metals of Co,Cd can exchanged with Ca in hydrated productionand be trapped in C-S-H,which formed new Co-containing calcium silicates andCd-containing calcium silicates.