多孔氧化铝陶瓷膜支撑体在HNO3溶液中的静态腐蚀

Static corrosion of porous alumina support of ceramic membrane in HNO_3 solutions

研究了在温度为45～90℃、浓度为1-10mol／L的HNO3溶液中，高铝多孔陶瓷膜支撑体的微观结构变化、质量损失率与时间的关系以及支撑体机械强度随其质量损失率的变化关系。结果表明，多孔氧化铝支撑体在酸性溶液中的腐蚀主要发生在支撑体颗粒之间的烧结颈部。建立了多孔支撑体的质量损失率与腐蚀时间的定量数学关系，并结合支撑体机械强度与其质量损失率的关系，对多孔支撑体在不同温度和浓度HNO3溶液中的使用寿命进行了预测。研究表明，多孔陶瓷膜支撑体具有优异的耐酸性能。

The corrosion rate, microstructure evolution and strength degradation of the macroporous support （99% Al2O3 content） immersed in HNO3 solutions （concentration in the range 1 mol/L to 10 mol/L, temperature in the range 45 to 90℃） were investigated experimentally. Results showed that the corrosion of the support in HNO3 solutions started at the sintered neck between Al2O3 particles. The surface area increased first in the initial stage of corrosion, as the substance existed in the sintered neck was corroded away. And then the surface area of the support decreased. The apparent corrosion rate increased with increment of concentration and temperature of HNO3 solution. The three point bending strength of corroded macroporous supports decreased as the weight loss of the support increased. Based on the microstructure evolution and Sato＇s investigation, a mathematical model between the weight loss of the support and the corrosion time in HNO3solution was established. The experimental results showed a good agreement with calculated results. According to the aforementioned mathematical model and the relationship between the bending strength and weight loss of the support, the life span of the macroporous support immersed in HNO3 solution can be easily calculated, which showed superior corrosion resistant properties.