State Key Laboratory of Water Resources and Hydropower Engineering Science, Wuhan University, Wuhan, China; Suzhou Institute of Wuhan University, Suzhou, China.
State Key Laboratory of Water Resources and Hydropower Engineering Science, Wuhan University, Wuhan, China.
Chemosphere. 2019 May;223:91-98. doi: 10.1016/j.chemosphere.2019.02.047. Epub 2019 Feb 11.
Ionic zinc is considered as an environmental pollutant. This work systematically investigated leaching mechanisms of calcium sulfoaluminate cement (CSA) pastes incorporated with/without ZnCl under the attacks of chloride and/or sulfate. The leaching behaviors of CSA pastes in the leaching solution are in-situ and continuously monitored by innovative non-contact electrical impedance measurement (NCEIM) and pH meter. The dissolution and diffusion during the leaching process are experimentally identified. Other techniques are also performed to verify the finding of NCEIM: the ion chromatograph and inductively coupled plasma optical emission spectrometer reveal the leaching or decomposition sequence of CSA pastes during the leaching process. Besides, results from XRD and SEM techniques demonstrate that main solid products in CSA pastes are ettringite and calcium monosulfoaluminate hydrates. The incorporation of Zn in the pastes has great impact on the decomposition of CSA pastes in the temperature elevation. External chloride and/or sulfate attacks significantly alter the pore structure of CSA pastes during the leaching process.
离子锌被认为是一种环境污染物质。本工作系统地研究了在氯化物和/或硫酸盐的侵蚀下，含/不含 ZnCl 的硫铝酸钙水泥（CSA）浆体的浸出机理。通过创新的非接触式电阻抗测量（NCEIM）和 pH 计，原位和连续监测 CSA 浆体在浸出溶液中的浸出行为。实验确定了浸出过程中的溶解和扩散。还采用其他技术来验证 NCEIM 的发现：离子色谱仪和电感耦合等离子体发射光谱仪揭示了 CSA 浆体在浸出过程中的浸出或分解顺序。此外，XRD 和 SEM 技术的结果表明，CSA 浆体中的主要固体产物是钙矾石和单硫铝酸钙水合物。锌的掺入对浆体中 CSA 的分解有很大的影响。在浸出过程中，外部氯化物和/或硫酸盐的侵蚀会显著改变 CSA 浆体的孔结构。
