(1. 湖南城市学院 材料与化学工程学院,益阳 413000;
2. 中南大学 冶金与环境学院,长沙 410083)
摘 要: 电解铁钨锡合金回收铁和富集钨锡是一种实现资源综合利用绿色可行的有效途径,本文利用电化学手段研究了铁钨锡合金粉电解的阳极行为。结果表明:铁钨锡合金粉电解过程只有铁发生电化学溶解,电解可实现铁与钨锡的分离,活化溶解区铁的溶解反应为扩散步骤控制的不可逆过程,温度升高有利于铁的溶解。铁钨锡合金粉相对于铁粉的自腐蚀电位正移了0.23 V,自腐蚀电流密度减小了86.67%,铁钨锡合金的阳极极化曲线斜率是铁粉的2.31倍,极化电阻是铁粉的6.75倍,铁钨锡合金粉中的铁比铁粉更难溶解。电流密度越大,铁钨锡合金越容易钝化,在适宜的电位范围内,电位越正越有利于铁的溶解。
关键字: 铁钨锡合金粉;电解;阳极行为;电化学;钝化
(1. School of Materials and Chemical Engineering, Hunan City University, Yiyang 413000, China;
2. School of Metallurgy and Environment, Central South University, Changsha 410083, China)
Abstract:The electrolytic recovery of iron and enrichment of tungsten and tin from Fe-W-Sn alloy is an effective and feasible way to achieve the comprehensive utilization of resources. The anode behavior of Fe-W-Sn alloy powder electrolysis was studied using electrochemical means. The results show that only the iron is electrochemically dissolved in the electrolysis process of the Fe-W-Sn alloy powder, and the separation of iron from tungsten and tin can be achieved by electrolysis. The iron dissolution reaction in the active dissolution region is an irreversible process controlled by the diffusion step, and the increase in temperature is beneficial to the dissolution of iron. Compared with the Fe powder, the self-corrosion potential of Fe-W-Sn alloy powder is positively shifted by 0.23 V, and the self-corrosion current density is reduced by 86.67%. The slope of the anode polarization curve of Fe-W-Sn alloy is 2.31 times higher than that of Fe powder, the polarization resistance of which is 6.75 times higher than that of Fe powder, and Fe in Fe-W-Sn alloy powder is much more difficult to dissolve than Fe powder. The higher the current density, the easier the Fe-W-Sn alloy is to be passivated. Within the appropriate potential range, the more positive the potential is, the more favorable the dissolution of Fe.
Key words: Fe-W-Sn alloy powder; electrolysis; anode behavior; electrochemistry; passivation