摘要
【目的】研究添加SiO2、Al2O3、MgO和CaO的含砷废渣在高温烧结过程中砷的环境释放行为,为含砷废渣的高温处理提供参考。【方法】称取一定量含砷废渣,分别加入质量分数30%的SiO2、Al2O3、MgO和CaO,采用翻滚振荡仪使物料完全混合,将混合物料在10MPa下加压成型,于400～1 100℃烧结1h,冷却后取烧结体进行毒性试验,研究不同烧结体中砷的浸出特性,并采用X射线衍射(XRD)对添加CaO后的含砷废渣及1 000℃高温烧结体的成分进行了分析与比较。【结果】浸出毒性试验表明,添加MgO、CaO对含砷废渣烧结体中砷的浸出有极大的抑制作用,说明MgO、CaO在含砷废渣高温烧结条件下对砷有一定的固定能力。1 000℃高温烧结条件下,CaO对含砷废渣中砷的抑制作用最强;XRD分析表明,CaO与砷化合生成了稳定的砷酸钙,使砷以砷酸钙形态存留于烧结体中,从而降低砷的浸出。【结论】从环境安全性角度出发,CaO和MgO是优良的含砷废渣烧结处理的添加剂。
【Objective】 This study investigated the effect of different additives on environmental release behavior of arsenic during sintering of arsenic-containing waste.【Method】 The raw materials were arsenic-containing waste with 30% mass fraction SiO2,Al2O3,MgO,and CaO.The raw materials were mixed by flip vibration instrument,shaped under the pressure of 10 MPa and exposed at 400-1 100 ℃ for 1 h.Sintered products were made after cooling,the arsenic leaching characteristics in different sintered products were studied,and the content of arsenic-containing waste and the sintered products at 1 000 ℃ with CaO were analyzed and compared using XRD.【Result】 Test on leaching toxicity showed that the inhibitory effects of MgO and CaO on arsenic leaching of the sinter were great,and MgO and CaO had certain fixed effect on arsenic during sintering of arsenic-containing waste.CaO had the most inhibitory effects on arsenic in arsenic-containing waste at 1 000 ℃,and XRD analysis showed that CaO and As combined and generated stable CaAs2O6,keeping as in the sintered products and reducing the release of arsenic leaching.【Conclusion】 Considering the product＇s environmental safety,MgO and CaO were excellent additives.
出处
《西北农林科技大学学报（自然科学版）》
CSCD
北大核心
2013年第6期91-97,共7页
Journal of Northwest A&F University(Natural Science Edition)
基金
国家自然科学基金项目(21107102)
关键词
含砷废渣
高温烧结
固化
浸出毒性
arsenic-containing waste
high temperature sintering
solidification
toxic leaching
