冷却水中缓蚀剂对贫铀的作用研究
Corrosion Inhibition Behaviors of Different Inhibitors for Depleted Uranium in Cooling Water
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摘要: 采用失重法测试了亚硝酸钠和钼酸钠分别与三乙醇胺复配对贫铀在冷却水中的缓蚀作用,并用激光拉曼光谱和扫描电子显微镜(SEM)分析了贫铀在不同温度冷却水中浸泡20 h后的表面。结果表明,亚硝酸钠和钼酸钠对贫铀均有缓蚀作用,加入三乙醇胺能够提高这两种缓蚀剂的缓蚀效率。冷却水温度为45 ℃和65 ℃时,钼酸钠与三乙醇胺复配的缓蚀效果分别达89%和88%。而冷却水温度为85 ℃时,亚硝酸钠与三乙醇胺复配后的缓蚀效率可达93.4%。拉曼光谱分析表明,铀表面的氧化物成分主要为UO2,钼酸根易在铀表面夹杂及划痕处吸附。SEM分析表明,缓蚀剂的加入能够促进铀表面氧化膜的致密性。Abstract: Inhibition effect of sodium nitrite and sodium molybdate combined with triethanolamine respectively for depleted uranium was evaluated in cooling water by weight-loss method. The corrosion surfaces of depleted uranium immersed in cooling water at different temperatures for 20 h were analyzed by laser Raman spectrum and scanning electron microscope (SEM). The results show that sodium nitrite and sodium molybdate have inhibition effect for depleted uranium. Inhibition efficiencies of the two inhibitors are improved by adding triethanolamine. Inhibition efficiencies of sodium molybdate combined with triethanolamine are 89% and 88% at 45 ℃ and 65 ℃, respectively. Inhibition efficiency of sodium nitrite is 93.4% at 85 ℃. Uranium dioxide is main component on uranium surface determined by laser Raman spectrum. The analysis of SEM indicates that the oxidation film formed on uranium surface is compact in cooling water with inhibitors.