连续电解精炼阴极铜过程中添加剂的作用

采用循环伏安法研究了浓度不同的几种添加剂(硫脲、聚丙烯酰胺、明胶和骨胶)对铜电解精炼过程的影响。结果发现,与未加添加剂的空白电解液相比,加入单一添加剂后铜沉积电流峰值明显提高,表明单一添加剂的加入会促进阴极铜的沉积。当在电解液中加入3.0 mg/L硫脲和2.4 mg/L聚丙烯酰胺作为复合添加剂时,铜沉积电流峰值与加入单一硫脲与聚丙烯酰胺时相比分别提高了31.2%与5.1%,表明二者有协同作用。结合扫描电镜(SEM)、能谱(EDS)和X射线衍射(XRD)对阴极铜的微观形貌、元素组成与物相进行表征,发现使用上述复合添加剂时,阴极铜的表面形貌与纯度最理想。

Roles of some additives in continuous electrolytic refining of cathode copper

The effects of different types of additives(i.e.thiourea,polyacrylamide,gelatin,and bone glue)with various concentrations on electro-refining of copper were studied by cyclic voltammetry.As compared with the blank electrolyte without any additive,it was found that the peak value of current for copper deposition was greatly increased after adding a single additive,indicating the every additive promoted the deposition of copper on cathode.The peak current was increased by 31.2%and 5.1%after adding a composite additive composed of thiourea 3.0 mg/L and polyacrylamide 2.4 mg/L as compared with that using thiourea and polyacrylamide individually,indicating that thiourea and polyacrylamide had a synergistic effect.The microscopic morphology,elemental composition,and phase constitution of cathode copper were characterized by scanning electron microscopy(SEM),energy-dispersive spectroscopy(EDS),and X-ray diffractometry(XRD).The results showed that the cathode copper electrodeposited by using the said composite additive had the best surface morphology and purity.