羰基镍珠在硫酸溶液中的溶解行为

摘要

The dissolution rates of common carbonyl nickel beads (CC) and high sulfur carbonyl nickel beads (HS) in sulfuric acid solution were compared by acid digestion method.The free corrosion potentials and free corrosion current densities of the two kinds of carbonyl nickel beads were also determined by electrochemical workstation.Microscopic corrosion morphology of the bead surfaces was observed by field emission scanning electron microscope.The corrosion products on the surfaces were analyzed by energy dispersive spectroscopy (EDS).The results show that the high sulfur carbonyl nickel bead was more easily soluble than the common carbonyl nickel bead in sulfuric acid solution,the corrosion potential of the former was more negative and its corrosion current density was higher.There were significant corrosion pits on the surface of the high sulfur carbonyl nickel bead after corrosion.The sulfur clement in high sulfur carbonyl nickel bead formed sulfide on its surface,which promoted the dissolution of the high sulfur carbonyl nickel bead.When nickel sulfide additive was added in the dissolution of common carbonyl nickel beads in sulfuric acid solution,the dissolution rate could be improved.%通过酸溶法测试比较了高硫羰基镍珠(HS)和常规羰基镍珠(CC)在硫酸溶液中的溶解速率,利用电化学工作站测试了这两种羰基镍珠的自腐蚀电位和自腐电流密度,并采用场发射扫描电子显微镜和能谱仪对两种镍珠腐蚀后的微观腐蚀形貌和腐蚀产物进行了分析.结果表明:高硫羰基镍珠比常规羰基镍珠在硫酸溶液中更易溶解,其自腐蚀电位更负,自腐蚀电流密度更大,腐蚀后其表面上存在明显的腐蚀坑;高硫羰基镍珠中的硫元素在其表面形成了硫化物,促进了高硫羰基镍珠的溶解;在溶解过程中添加硫化镍,可提高常规镍珠在硫酸溶液中的溶解速率.