Corrosing Prevention of Insoluble Anode for Steel Strip Electroplating

传统的析氧金属电极（iro_2 - ta_2o_5包覆钛电极）由于其耐久性差，在钢带电镀中是不实用的。本研究的目的是通过在钛基板上形成保护玻璃涂层来延长电极的使用寿命。该玻璃涂层是由熔块和硅化物的混合物烧结而成的。估计涂层的欧姆损耗约为1.2mV，对电池电压的影响很小。在煮沸的硫酸溶液中浸泡试验表明，玻璃涂层具有防钛腐蚀的作用。用含有无机添加剂的H_2IrCl_6溶液涂覆玻璃基板，并反复烧制。所制备的金属电极在含有机增白剂的硫酸溶液中作为阳极进行了测试。催化剂的使用寿命随着涂层数量的增加而增加，随着有机剂含量的增加而降低。玻璃涂层和无机添加剂对延长使用寿命有显著作用。观测结果在对数坐标纸上以直线的形式描述。这些关系使预测长期使用寿命的大小成为可能。研究了不溶性阳极在电解液净化中的新应用。氯离子是回收资源中硫酸锌溶液中的常见污染物，必须在后续电解之前去除。在配备这种大面积阳极的循环电池中，阴离子可以有效地消除。

Conventional metal electrodes for oxygen evolution (IrO_2-Ta_2O_5-coated titanium electrodes) are impractical in steel strip electroplating because of their poor durabiblity. The purpose of the present study is to extend the service life of the electrodes by forming protective glass coatings on titanium substrates. The glass coatings were prepared by sintering an admixture of frit and silicide. Ohmic losses in the coatings were estimated to be about 1.2mV and have little influence on cell voltage. Immersion test in boiled sulfuric acid solutions showed that the glass coatings prevent titanium from corroding. The glass-coated substrates were painted with H_2IrCl_6 solutions containing some inorganic additives and fired repeatedly. The metal electrodes thus prepared were tested as anodes in sulfuric acid solutions containing organic brighteners. The service life increased with increasing number of catalyst paintings and decreased with increasing content of the organic agents. The glass coatings and the inorganic additives exert a noticeable effect on the extension of the service life. The observations were described in the forms of straight lines on logarithmic graph paper. The relations make it possible to predict the magnitude of the long-term service life. A novel use of insoluble anodes in the purification of electrolytic solution was also studied. Chloride ion, a common contaminant in zinc sulfate solutions from recycled resources, must be removed prior to the succeeding electrolysis. In a recirculation cell equipped with such anodes of large area, the anion may be effectively eliminated.