不锈钢钢渣用作水泥混合材及其安全性分析

Safety Analysis of Stainless Steel Slag Used as Composite Cement Admixture

研究了不锈钢钢渣作为水泥混合材的可行性及安全性.结果表明:不锈钢钢渣主要矿物组成为硅酸二钙和镁硅钙石,还有少量的含铬矿物,具有一定的胶凝活性,易磨性较好;掺入适量的不锈钢钢渣可以配制出符合标准要求的复合水泥,当不锈钢钢渣掺量(质量分数)为32%时,可以生产32.5复合水泥,掺量为25%时,可以生产42.5复合水泥;不锈钢钢渣中重金属主要以稳定态存在,其浸出浓度远低于危险废物鉴别标准限值,也低于铬渣用作水泥混和材国家标准限值,且铬主要以3价态存在;不锈钢钢渣的放射性内、外辐照指数均低于1.0,满足作为建筑材料的放射性国家标准要求;不锈钢钢渣作为水泥混合材安全、可行.

The feasibility of stainless steel slag used as composite cement admixture were studied. The results indicate that stainless steel slag shows cementitious activity to a certain extent owing to composition of the phases of Ca2SiO4 and Ca3Mg（SiO4）2. It is easy to be ground. Grades P . C32.5 and P .C42.5 composite cement can be formed by mixing 32% and 25% stainless steel slag with Portland cement respectively. The results also show that most of the heavy metals in the stainless steel slag exist as stable composition, of which the leaching concentration is far lower than the limit values of identification standards for hazardous waste and lower than the limit values of national standards for chromium slag used as cement ad- mixture. The main heavy metal, chromium, exists as less hazardous trivalent chromium. The internal exposure index（IRa） and the external exposure index（Iy） of the stainless steel slag are both lower than 1.0 which satisfy the requirements of national limit of radioactivity in building materials. Therefore, the stainless steel slag can be safely used as admixture of Portland cement to produce composite cement.