摘要
针对我国面临的严重铬污染威胁,进行了将铬污染土壤与粉煤灰混合后在高温下解毒,获得陶粒产品以实现资源化利用的研究。通过单因素试验,以Cr(Ⅵ)浸出浓度和陶粒颗粒强度为控制指标,优选陶粒制备的焙烧工艺参数;通过正交试验得到最优陶粒产品,并分析焙烧工艺条件对陶粒性能的影响机制。结果表明,在焙烧温度1 120℃、粉煤灰添加量25%、焙烧时间10min的试验条件下得到了最佳的陶粒产品;其中焙烧温度是影响陶粒性能的关键因素,对陶粒颗粒强度、表观密度、1h吸水率均影响显著;最终陶粒产品堆积密度等级为600级,筒压强度为3.0 MPa,属于普通轻集料优等品;陶粒浸出液Cr(Ⅵ)浓度0.042 mg/L,浸出液总铬浓度0.045mg/L,安全性能符合《铬渣污染治理环境保护技术规范》(HJ/T301)对铬污染土壤解毒后用于混凝土骨料的处理要求。
The chromium pollution is serious problem in China.The objective of this study is detoxification of chromium contaminated soil with fly ash at high temperatures,and obtain the pottery products in order to realize the utilization of r Cr(VI)esources.The parameters of leaching concentration and ceramsite particle strength were selected to optimize the roasting parameters of ceramsite preparation by using single factor test.The optimum ceramsite products were obtained by orthogonal test.The effect mechanism of sintering process conditions on the properties of ceramsite was analyzed.The results shown that(1)the Ceramsite Cr(Ⅵ)has achieved the good solidification stabilization effect under the test condition;(2)the sintering temperature affect the ceramsite particle strength,apparent density,1h water absorption rate at significant level;(3)the optimum sintering process condition is the 25%fly ash addition quantity,with the 1 120℃sintering temperature and the 10 min sintering time;(4)the final ceramsite products belongs to the ordinary lightweight aggregate with packing density of 600 kg/m 3,and barrel compressive strength of 3.0 MPa;(5)the concentration of Ceramsite Cr(Ⅵ)is 0.042 mg/L,and the total chromium concentration of the leaching liquid is 0.045 mg/L.The safety performance accord with the technical code for environmental protection of chromium residue pollution control(HJ/T301)for the treatment of concrete aggregates with chromium-contaminated soil after detoxification.
作者
杨威
陈一萱
王海超
雷晓玲
曾祯
YANG Wei;CHEN Yixuan;WANG Haichao;LEI Xiaoling;ZENG Zhen(National Engineering Research Center for Inland Waterway Regulation,Chongqing 400074,China;Chongqing Academy of Science and Technology,Chongqing 401123,China)
出处
《功能材料》
EI
CAS
CSCD
北大核心
2018年第9期9169-9173,9179,共6页
Journal of Functional Materials
基金
重庆市教委资助项目(KJ1400323)
重庆市科委资助项目(cstc2016jcyjA0428)
重庆市博士后特别资助项目(Xm201606)
关键词
铬污染土壤
粉煤灰
干法解毒
资源化
混凝土轻集料
chromium contaminated soil
fly ash
dry method detoxification
resource recovery
concrete lightweight aggregate
