锅炉酸洗中应慎用亚硫酸钠和联氨作还原剂

Prudently Using NaSO_3 and N_2H_4 As Deoxidizer in Boiler Acid Cleaning

一般的酸洗缓蚀剂只能抑制H^+对铁的腐蚀,却不能抑制Fe^(3+)对铁的腐蚀,因此在酸洗中,当Fe^(3+)浓度过高时,须加入还原剂,将Fe^(3+)还原成Fe^(2+)。在锅炉酸洗中,常用亚硫酸钠或联氨作还原剂,但实际上这两种试剂都只能在碱性溶液中作还原剂,在酸性介质中不但还原性差,有时甚至反而成了氧化剂,加剧金属的腐蚀。本文根据实验数据和电化学理论,对锅炉酸洗中用亚硫酸钠和联氨作还原剂的危害进行了探讨。

Ordinary inhibitors for acid only inhibit H+ From corroding iron, but cannot inhibit Fe3 + Therefore, in acid cleaning, the deoxidizer would be employed which reduce Fe3+ to Fe2+ if the concentration of Fe3+ is too high in boiler acid cleaning, Na2SO3 and N2H2 are often used as reductants, but in fact these deoxidizer can only be used in alkaline solution. In acid, both of them were not only oxidants, but also caused severe corrosion. According to test data and electrochemistry theory, the paper gives a discussion about the dangerous of using Na2SO3 and N2H4 as deoxidizer in boiler acid cleaning.