磷酸钾镁水泥中硫酸根离子扩散研究

Research on the Diffusion of Sulfate Ions in Potassium Magnesium Phosphate Cement

通过磷酸钾镁水泥(Potassium magnesium phosphate cement,MKPC)在5%Na2SO4溶液中的长期浸泡、冻融循环和电脉冲试验,并测定其中不同深度和不同侵蚀时间的硫酸根扩散浓度,分析MKPC在不同侵蚀环境中的硫酸根扩散规律,基于Fick扩散定律求解不同条件下硫酸根离子扩散系数。结果表明:MKPC在三种侵蚀条件中的硫酸根扩散浓度均随侵蚀时间增加而增大,且硫酸根最大扩散深度x与侵蚀时间t之间关系遵循幂函数x=atb;求得冻融循环和电脉冲的硫酸根扩散系数相比长期浸泡环境高一数量级,冻融循环和电脉冲均能有效加快硫酸根在MKPC中的迁移扩散。

The long-term immersion,freeze-thaw cycle and electrical pulse test of potassium magnesium phosphate in five percent sodium sulfate solution were carried out,and measuring the diffusion concentration of sulfate radical in different depths and different erosion times,the diffusion law of sulfate radical in different erosive environment of MKPC was analyzed.It was based on the Fick’s diffusion law to solve the diffusion coefficient of sulfate ion under different conditions.The results show that the diffusion concentration of MKPC in the three kinds of erosion conditions increases with the increase of erosion time.The relationship between the maximum diffusion depth of sulphate root and the time of erosion follows a power function x=at b.The diffusion coefficient of the sulfate radical of the freeze-thaw cycle and electric pulse is one order of magnitude higher than that of the long-term soaking environment.Both freeze-thaw cycle and electric pulse can effectively accelerate the migration and diffusion of sulfate in MKPC.