Haiying Zhang, Youcai Zhao, Jingyu Qi
Department of Environmental and Energy Engineering, Shanghai Institute of Technology, Shanghai, China.
J Hazard Mater. 2007 Mar 6;141(1):106-14. doi: 10.1016/j.jhazmat.2006.06.100. Epub 2006 Jul 1.
In this work, MSWI (municipal solid waste incineration) fly ash is used as a blending in production of ceramic tile by taking advantage of its high contents of SiO(2), Al(2)O(3) and CaO. Besides, macro-performance and microstructure of the product as well as its leaching toxicity in practical application were studied by means of XRD, IR and SEM analysis, and leaching toxicity and sequential chemical extraction analysis of the product. It is found that when 20% fly ash is added, the product registers a high compressive strength of 18.6MPa/cm(2) and a low water absorption of 7.4% after being sintered at 960 degrees C. It is found that the glazed tile shows excellent resistance against leaching, in accordance with HVEP stand, of heavy metals with Cd<0.0002ppm, Pb<0.0113ppm and Zn<0.0749ppm, and Hg below the low detection limit. These results show that heavy metals are cemented among the solid lattice in the product and can hardly be extracted. Leaching toxicity of heavy metals in the product, especially Hg, Pb, Zn and Cd, is substantially reduced to less than one-tenth of that in fly ash. In addition, specifications of Hg, Pb, Zn and Cd are largely changed and only a small portion of these heavy metals exists in soluble phases. These results as a whole suggest that the use of MSWI fly ash in ceramic tile constitutes a potential means of adding value.
在这项工作中，城市固体废弃物焚烧（MSWI）飞灰因其高含量的SiO₂、Al₂O₃和CaO而被用作瓷砖生产的掺和料。此外，通过XRD、IR和SEM分析以及产品的浸出毒性和连续化学萃取分析，研究了产品的宏观性能、微观结构及其在实际应用中的浸出毒性。结果发现，当添加20%的飞灰时，产品在960℃烧结后具有18.6MPa/cm²的高抗压强度和7.4%的低吸水率。结果发现，根据HVEP标准，该釉面砖对重金属具有优异的抗浸出性，镉含量低于0.0002ppm，铅含量低于0.0113ppm，锌含量低于0.0749ppm，汞含量低于检测下限。这些结果表明，重金属在产品的固体晶格中被胶结，难以被提取出来。产品中重金属的浸出毒性，尤其是汞、铅、锌和镉，大幅降低至飞灰中的十分之一以下。此外，汞、铅、锌和镉的形态发生了很大变化，只有一小部分这些重金属以可溶态存在。总体而言，这些结果表明在瓷砖中使用MSWI飞灰是一种潜在的增值手段。
