升温条件下V-H_2O系电位-pH图  

POURBAIX DIAGRAMS FOR V-H_2O SYSTEM AT ELEVATED TEMPERATURES

作　　者：周雪娇[1] 魏昶[1] 李旻廷[1] 邱爽[1] 

机构地区：[1]昆明理工大学冶金与能源工程学院,昆明650093

出　　处：《矿冶》2010年第4期34-40,共7页Mining And Metallurgy

基　　金：国家自然科学基金资助课题(50874053);云南省科技厅资助项目(2007GA010)

摘　　要：根据热力学原理及相关计算,绘制了升温条件下钒水系电位-pH图。探讨了可溶钒物种活度(10-6,10-4,10-2,100)以及温度(25,150℃)对钒水系电位-pH图的影响。结果显示,钒氧化物的稳定区(即钝化区)随着温度及活度的提高明显增大。通过计算可知,在25℃条件下,当钒物种活度低于10-3.51时,五氧化二钒稳定区即消失;150℃条件下,五氧化二钒稳定区消失的临界活度则是10-3.17。金属钒的稳定区(即免蚀区)基本不受温度的影响,但随着可溶钒物种活度的提高有所增大。从理论上预测钒抗腐蚀性能不受高温影响。Pourbaix diagrams（potential/pH diagrams） for V-H2O system were presented at elevated temperature based on the principle and calculation of thermodynamic.Vanadium-containing solutions with activities of 10^-6,10^-4,and 10^-2 at 25 ℃,and with activity of 100 for 25 and 150℃,were discussed.The Pourbaix diagrams showed that the ranges of vanadium oxides（passivation） extended with increasing temperatures and increasing activities of dissolved species.Calculations indicated that the stability domain of V2O5（s） disappeared when the activities of dissolved species were lower than 10^-3.17 and 10^-3.51 at 25℃ and 150℃,respectively.The stability region for vanadium（immunity） was nearly independent of temperature,but grew with increased activity.The corrosion resistance was nearly not affected by high temperature in theory.

关 键 词：V-H2O系 电位-PH图 钝化区 免蚀区 

分 类 号：TF841.3[冶金工程—有色金属冶金] TQ150[化学工程—电化学工业]