Preparation of sulfoaluminate cementitious material using harmful titanium gypsum:material properties and heavy metal immobilization characteristics  

作　　者：Jingwei Li Wenlong Wang Dong Xu Xujiang Wang Yanpeng Mao 

机构地区：[1]Shandong Engineering Laboratory for Solid Waste Green Materials,National Engineering Laboratory for Reducing Emissions From Coal Combustion,Engineering Research Center of Environmental Thermal Technology of Ministry of Education,Shandong Key Laboratory of Energy Carbon Reduction and Resource Utilization,School of Energy and Power Engineering,Shandong University,Jinan 250061,Shandong,China [2]School of Civil Engineering,Shandong Jianzhu University,Jinan 250101,China

出　　处：《Waste Disposal and Sustainable Energy》2020年第2期127-137,共11页废弃物处置与可持续能源（英文）

基　　金：funded by the National Key Research&Development Program of China(No.2017YFC0703100).

摘　　要：The production of titanium dioxide(a necessary industrial color additive)can generate massive amount of titanium gypsum,a hard-to-treat solid waste.Diverse metallic impurities,heavy metals and reddish color in titanium gypsum make it difficult to be used in building materials like other by-product gypsums.As a result,most of titanium gypsum in China is just stored and has caused serious environmental issues.In this study,titanium gypsum,which contained high contents of impurities and heavy metals,was synergistically used with other three solid wastes to prepare sulfoaluminate cementitious material(SACM)for the first time.The mass proportion of titanium gypsum in the raw materials exceeded 25%.The chemical,mechanical and heavy metal leaching characteristics of this solid waste-based SACM were tested via XRD,XRF,ICP-OES,etc.The main components and metallic impurities of titanium gypsum could be transformed to the components of the main mineral of SACM,ye’elimite.The compressive strength of the prepared SACM reached 38.2,59.7 and 95.8 MPa at 1-day,3-day,and 28-day hydration,respectively,indicating the features of rapidly hardening and high strength.Importantly,the solid waste-based SACM could effectively solidify the heavy metals contained in titanium gypsum and other raw material during thje hydration process.The retention ratio of total Cr reached 97.5%,and other heavy metals were almost not detected in the leachate of SACM.This study provided a feasible approach to utilize titanium gypsum to produce high-performance,green building material,and might promote the massive utilization of this solid waste.

关 键 词：Titanium gypsum Solid waste Sulfoaluminate cementitious material Synergistic utilization Heavy metals Solidification characteristics 

分 类 号：X705[环境科学与工程—环境工程]