不锈钢渣资源利用特性与重金属污染风险

研究了2种不锈钢渣——电炉(EAF)钢渣和转炉(AOD)钢渣可资源化利用和重金属污染特性.结果表明:2种钢渣的粒径主要分布于小于5 mm的范围内；EAF钢渣的主要元素(w>1%)为Ca，Si，Mg，Al，Fe，O和Cr，主要矿物质为Ca₂SiO₄和Ca₃Mg(SiO₄)₂；而AOD钢渣主要由Ca，Si，Mg，C和O等元素组成，主要矿物质为Ca₂SiO₄，资源化利用潜力大.不锈钢渣浸出毒性测试结果表明:除Cr外，所有重金属浸出质量浓度均低于或接近于检测限，Cr浸出质量浓度小于0.2 mg/L，远低于危险废物鉴别标准(GB5085.3-1996)相应限值，且重金属主要以稳定的化学形态存在；根据有效浸出测试结果，不锈钢渣中的Cr在最不利条件下存在溶出风险，但以毒性较低的Cr(Ⅲ)为主，与X射线衍射测试结果一致.因此，不锈钢渣中的重金属浸出污染风险低. 

Beneficial Reuse of Stainless Steel Slag and Its Heavy Metals PollutionRisk

The feasibility of beneficial reuse of two kinds of stainless steel slag, electric arc furnace (EAF) slag and argon oxygen decarburization furnace (AOD) slag, and their pollution properties of heavy metals were studied. The results indicate that the majority of the slags were sized <5 mm. The main elements (mass content>1%) in the EAF slag were Ca, Si, Mg, Al, Fe, O, and Cr, existing asCa₂SiO₄ and Ca₃Mg(SiO₄)₂, while the AOD slag was mainly composed of Ca, Si, Mg,C, and O, and the main minerals were Ca₂SiO₄. The slags were suitable for beneficial reuse. The leaching mass concentrations of all heavy metals except Cr by the leaching test were lower than or close to the detection limit. The leaching mass concentration of Cr was <0.2 mg/L, far lower than the limit values of Identification Standards for Hazardous Wastes (GB5085.3-1996). Most of the heavymetals existed as stable speciation. The availability leaching test results show that Cr could be leached out at the “worst scenario”, but mainly as the less hazardous Cr(Ⅲ), which was confirmed by the XRD analysis results. Therefore, the pollution risks of the heavy metals in the stainless steel slags were low.