Mechanism of enhanced arsenic sulfide stabilization/solidification by using steel slag and carbide slag
With the development of metal smelting and other industries,a large amount of arsenic sulfide slag that is difficult to handle is accumulated,causing serious harm to resources,the environment and human health.The stabilization/solidification technology represents a highly efficient method for fixing arsenic with promising applications.However,the high reagent consumption and cost,along with limited efficacy in treating complex and highly concentrated arsenic slag,have hindered the progress of this technology.In this study,low-cost and highly active steel slag and carbide slag were employed instead of chemical stabilizers to create an advanced oxidation/stabilization system through acid-activated steel slag,iron ions,and H2O2,then it was solidified with cement.The aforementioned processes were characterized by using XRD,FTIR,XPS techniques and so on.It is demonstrated that the low-valence arsenic compounds,sulfur compounds,and organic substances are effectively oxidized to form stable high-valence calcium iron salts while maintaining structural stability after solidification.Following process optimization steps involving 0.2 g steel slag,0.5 g H2O2,0.3 g carbide slag,and 1.0 g cement for stepwise synergistic stabilization/solidification treatment of 1.0 g arsenic sulfide slag,the compressive strength of the solidified body is 5.7 MPa,and the arsenic leaching concentration is only 0.66 mg·L-1,which is far lower than the safe landfill standard of 1.2 mg·L-1.
万方数据
维普
