基于Al3+固体电解质的热镀锌液中在线测定铝传感器的研究

In hot dip galvanizing process, Al content in zinc bath strongly affects coating structure and properties of hot dip galvanizing products. So, it is very important to develop a Al sensor which can on-line monitor and control Al activities in zinc bath for improving products quality and increasing production efficiency. In this proposal,a concentration cell Al sensor will be fabricated with (Al0.2Zr0.8)20/19Nb(PO4)3 based high temperature Al3+ conductor as electrolyte and Zn-Al alloys as reference electrode. The proposed research work will include：(1)According to first principle calculations and experimental results, effect of doping in Al and P site of (Al0.2Zr0.8)20/19Nb(PO4)3 on its ionic conductivity will be investigated in order to obtain Al3+ conductor with high performance;（2）effect of sintering additives on sinterability, microstructure, electrical properties and stability of above-mentioned material system in zinc bath will be addressed;（3）influential factors on sensing properties of the sensor will be determined; (4) the relating model among Al activity coefficient, Al content and temperature in Zn-Fe-Al system will be established; (5) the Al sensor will be tested in industrial production and the sensor performances will be evaluated and further modified. By proposal research work, an Al sensor with high performance will be obtained and some scientific problems involving in preparation and sensing behavior of the Al sensor will be adressed. Some results with our own intellectual property will be achieved. The results will lay a solid foundation in theory and experimental aspect for industrial application of the Al sensor.

在热镀锌中，锌池中有效铝含量强烈影响镀层结构和性能，因此研究铝传感器，实现锌池中有效铝的连续、在线检测对提高产品质量和生产效率有重要意义。本项目以(Al0.2Zr0.8)20/19Nb(PO4)3基Al3+导体为电解质，铝合金为参比电极，制备浓差电池型铝传感器。拟研究：（1）通过第一性原理计算和实验相结合，研究(Al0.2Zr0.8)20/19Nb(PO4)3中Al和P位搀杂对其铝离子电导率的影响规律，获得高性能Al3+导体；（2）烧结助剂对材料的烧结性能、导电性能及在锌液中稳定性的影响规律；（3）建立在Al-Zn-Fe三元体系中Al活度系数与浓度和温度关系模型；（4）确定影响铝传感器敏感性能的各种因素；（5）对铝传感器进行现场实验，进一步评估和改进传感器性能。通过本项目研究，获得高性能铝传感器，弄清相关的科学问题，取得具有自主知识产权的成果，为传感器的实际应用奠定理论和实验基础。

在带钢热镀锌生产中，铝作为锌液中最重要的添加元素，其有效含量强烈影响镀层结构和性能，因此研究铝传感器，实现锌池中有效铝的连续、在线、实时检测对改善产品质量，提高生产效率有重要意义。本项目采用固态反应法制备了Nb位、Zr位、P位或O位掺杂的(Al0.2Zr0.8)19/20NbP3O12基电解质，探明了掺杂元素半径、电负性及元素协同作用对电解质相纯度、烧结性能、微观结构和电导率的影响规律，确定了不同离子和位置掺杂的(Al0.2Zr0.8)19/20NbP3O12均为纯铝离子传导。筛选出了几个烧结性能好、电导率高的材料体系，电导率提高了2-10倍，离子迁移数大于0.99。在 (Al0.2Zr0.8)19/20NbP3O12基电解质中加入LiF等烧结助剂，不仅提高了电解质烧结性能和相纯度，还显著增大了材料电导率。筛选出的烧结助剂使电导率提高了2-3倍，离子迁移数大于0.99。. 建立了以掺杂的(Al0.2Zr0.8)19/20NbP3O12为电解质，2%Al-Zn合金为参比电极的浓差电池型Al传感器结构和组装工艺。传感器对锌熔体中的铝显示了快速响应，部分传感器的测定值接近理论值。以掺杂的(Al0.2Zr0.8)19/20NbP3O12和AlCl3-NaCl构成双电解质，纯铝丝为参比电极组成浓差电池型Al传感器。传感器对锌熔体中的铝显示良好响应，在低浓度下，传感器的测定值接近理论值。通过研究，获得了一些较好性能铝传感器，初步弄清了在传感器制备和响应中的一些关键科学问题，解决了一些技术瓶颈，取得一些自主产权成果，为传感器的工业应用奠定了基础。. 将上述思想和方法进行延伸和扩展，本工作还成功地制成了新型NH3传感器和NO2传感器。以(Al0.2Zr0.8)19/20NbP3O12基铝离子导体为电解质制备了Nernst型NO2传感器，传感器在低温下有良好的敏感行为。以(Al0.2Zr0.8)19/20NbP3O12基铝离子导体为电解质制备了混合位型NH3传感器，取得了满意结果。确定了敏感材料组成，微观结构，三相界面结构等对传感器性能的影响规律，探讨了响应机理。本项目实施过程中，发表相关期刊论文22篇，获得国家发明专利1项（2018），培养研究生11名。