磷渣基胶凝材料固化含砷废渣影响因素研究

Solidification of Arsenic Containing Solid Wastes using Phosphorus Slag Based Cementious Material

利用磷渣基胶凝材料为基体材料,对砷含量为7.62%的砷钙渣进行固化处理,可实现砷的安全固化。本文主要考察了化学外加剂、养护方式、骨料掺量等因素对砷固化体抗压强度和砷毒性浸出特性的影响。结果表明：Fe Cl3的掺量在0.5%-1.5%时,可有效地降低固化体砷毒性浸出,硫酸盐的掺量在0.6%-0.8%时,固化体的力学性能得到很好的提升;随着养护温度和压力的升高,固化体力学性能提高,砷毒性浸出浓度降低;固化过程中骨料的较佳掺量为15%-20%。XRD和SEM分析表明,固化体中砷主要以Al As O4和Ca2As2O7等盐类形式存在,且被生成的水化硅酸钙凝胶及类沸石结构体牢牢地吸附和包裹。

The process of secured solidification on arsenic consisting of 7.62% of arsenic calcium slag could be achieved based on the phosphorus slag cementing material that acts as an alkaline activator. Moreover some factors such as chemical additive, curing methods and aggregate content that could have an impact on arsenic solidified block- intensity and the concentration of arsenic toxicity leaching also will be critically analysed and evaluated in the paper. Research results show that the FeCl3 has certain influenced on the strength of the solidified body and the compression strength would be high when its amount is less than 0.5%-1.5%, the mechanics properties of the solidified body is better when the amount of sulfate is between 0.6% and 0.8%, the function of solidified body could be improved if we increase the curing temperature and pressure, the amount of sand should be controlled at around 15%- 20% during the process. Finally, according to the analysis of XRD and SEM, the solidified arsenic is present at the form of salts such as AlAsO4 and Ca2As2O7 and is generated and adsorbed firmly by the hydrated calcium silicate gel and the zeolite structure.