含铅钢渣制备钢渣水泥的试验研究

Research on the preparation of steel slag cement with lead-adsorbed steel slag

采用钢渣处理含铅废水,将吸附有Pb2+的钢渣作为混合材制得钢渣水泥。测定了钢渣水泥的标准稠度用水量、凝结时间、胶砂流动度、强度等物理性能,并通过X射线衍射(XRD)、扫描电镜(SEM)和水化热测试等手段分析钢渣水泥的微观水化性能与结构,测定钢渣水泥的Pb2+浸出浓度。结果表明,钢渣能有效处理含铅废水,当Pb2+与钢渣的投加质量比为1∶10时,废水中Pb2+的去除率可达80.04%,钢渣对Pb2+的吸附容量为80mg/g。将此含铅钢渣作为混合材制备钢渣水泥,当含铅钢渣掺杂量低于20%(质量分数,下同)时,制备的水泥试样强度等级达到52.5R;当含铅钢渣掺杂量为40%时,水泥试样强度等级达到42.5R;XRD与SEM分析表明,制得的钢渣水泥未出现异常水化产物;含铅钢渣未导致水泥水化延迟,且钢渣水泥中的Pb2+在酸性和中性环境下的浸出浓度均满足《危险废物鉴别标准浸出毒性鉴别》(GB 5085.3—2007)。

Steel slag was applied to treat lead containing wastewater, the obtained lead-adsorbed steel slag was used as mixture to prepare slag cement. The water needed under normal consistency, setting time, mortar fluidity, strength and other physical properties of slag cement was detected. The micro-hydration performance and structure of slag cement was characterized by X-ray diffraction （XRD）, scanning electron microscopy （SEM） and hydration heat testing. The leaching concentration of Pb2＋ from slag cement was also determined. Results show that Pb2＋ could be well adsorbed on the surface of steel slag. 80.04% of Pb2＋ in wastewater could be removed when the mass ratio of Pb2＋ to steel slag was 1 ：10,with the Pb2＋ adsorption capacity was 80 mg/g. When the doping content of lead-adsorbed steel slag was less than 20%, the strength of obtained cement could reach 52.5R grade, when the doping content was 40%, cement strength could reach 42.5R grade. XRD and SEM showed that there was no abnormal hydration product produced, and Pb2＋ in slag cement did not delay the cement hydration. The leaching concentration of Pb2＋ was less than the regulation values of the ＂Identification standard for hazardous wastes＂ （GB 5085.3-2007）.