Corrosing Prevention of Insoluble Anode for Steel Strip Electroplating

传统的析氧金属电极(IrO_2-Ta_2O_5涂层钛电极)由于耐久性差，在带钢电镀中不实用。本研究的目的是通过在钛衬底上形成保护玻璃涂层来延长电极的使用寿命。玻璃涂层是由熔块和硅化物的混合物烧结而成的。涂层中的欧姆损耗估计约为1.2 mV，对电池电压几乎没有影响。在沸腾的硫酸溶液中的浸泡试验表明，玻璃涂层防止了钛的腐蚀。用含有一些无机添加剂的H_2IrCl6溶液涂覆玻璃基板，并重复烧成。所制备的金属电极在含有有机光亮剂的硫酸溶液中进行了阳极测试。催化剂的使用寿命随催化剂涂层数量的增加而增加，随有机试剂含量的增加而减少。玻璃涂层和无机添加剂对延长使用寿命有显著作用。观测结果在对数图纸上以直线的形式描述。这些关系使得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一种常见污染物，在后续的电解之前必须去除。在配备这种大面积阳极的再循环槽中，可以有效地消除阴离子。

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.