State Key Laboratory for Coal Mine Disaster Dynamics and Control, Chongqing University, Chongqing 400044, China.
School of Resources and Safety Engineering, Chongqing University, Chongqing 400044, China.
Int J Environ Res Public Health. 2021 Sep 22;18(19):9960. doi: 10.3390/ijerph18199960.
Lead-zinc smelting slag (LZSS) is regarded as a hazardous waste containing heavy metals that poses a significant threat to the environment. LZSS is rich in aluminosilicate, which has the potential to prepare alkali-activated materials and solidify hazardous waste, realizing hazardous waste cotreatment. In this study, the experiment included two parts; i.e., the preparation of alkali-activated LZSS (pure smelting slag) and chromite ore processing residue (COPR) solidification/stabilization. Single-factor and orthogonal experiments were carried out that aimed to explore the effects of various parameters (alkali solid content, water glass modulus, liquid-solid ratio, and initial curing temperature) for alkali-activated LZSS. Additionally, compressive strength and leaching toxicity were the indexes used to evaluate the performance of the solidified bodies containing COPR. As a result, the highest compressive strength of alkali-activated LZSS reached 84.49 MPa, and when 40% COPR was added, the strength decreased to 1.42 MPa. However, the leaching concentrations of Zn and Cr from all the solidified bodies were far below the critical limits (US EPA Method 1311 and China GB5085.3-2007). Heavy-metal ions in LZSS and COPR were immobilized successfully by chemical and physical means, which was detected by analyses including environmental scanning electron microscopy with energy-dispersive spectrometry, Fourier transform infrared spectrometry, and X-ray diffraction.
铅锌冶炼渣 (LZSS) 被认为是一种含有重金属的危险废物，对环境构成重大威胁。LZSS 富含铝硅酸盐，具有制备碱激活材料和固化危险废物的潜力，实现了危险废物的共处理。本研究包括两部分实验，即碱激活 LZSS（纯冶炼渣）和铬铁矿加工残渣（COPR）的固化/稳定化。通过单因素和正交实验，探讨了各种参数（碱固含量、水玻璃模数、液固比和初始养护温度）对碱激活 LZSS 的影响。此外，抗压强度和浸出毒性是评估含有 COPR 的固化体性能的指标。结果表明，碱激活 LZSS 的最高抗压强度达到 84.49 MPa，当添加 40% COPR 时，强度降至 1.42 MPa。然而，所有固化体中 Zn 和 Cr 的浸出浓度均远低于临界限值（美国 EPA 方法 1311 和中国 GB5085.3-2007）。通过环境扫描电子显微镜与能谱分析、傅里叶变换红外光谱和 X 射线衍射等分析手段，成功地采用化学和物理手段固定了 LZSS 和 COPR 中的重金属离子。
