(中南大学 冶金与环境学院，长沙 410083)
摘 要: 采用过氧化合物为引发剂，以明胶和丙烯酰胺为原料合成得到明胶-丙烯酰胺接枝共聚物(PGAM)，并将PGAM作为铜电解添加剂应用于铜电解精炼。结果表明：PGAM能够替代硫脲用作铜电解添加剂，且对电解液中的漂浮阳极泥具有很好的絮凝作用。使用PGAM、明胶和骨胶作为添加剂时，在电解液温度为65 ℃、电流密度为235 A/m2的条件下，电解168 h后，所得高纯阴极铜中As、Sb和Bi含量分别为5.1×10-7、1.24×10-6、6.9×10-7，远低于使用硫脲、明胶和骨胶作为添加剂时所得阴极铜中相应杂质含量。电解所得阳极泥中，As、Sb和Bi含量分别为5.12%、4.04%和1.01%；而硫脲、明胶和骨胶为添加剂时，阳极泥中As、Sb和Bi含量分别为3.25%、2.20%和1.95%，表明PGAM有利于电解液中As和Sb的沉降。线性扫描伏安测试表明：PGAM在Cu2+还原过程中起极化作用，提高了Cu2+还原峰电流密度；与明胶和骨胶共同使用时，其极化作用减弱，峰电流密度降低。
关键字: 铜电解精炼；添加剂；明胶-丙烯酰胺接枝共聚物；硫脲；明胶
（School of Metallurgy and Environment, Central South University, Changsha 410083, China）
Abstract:The gelatin-acrylamide graft copolymer (PGAM) was synthesized by acrylamide and gelatin using peroxide as initiator, and the PGAM was applied in copper electrorefining as additive for the first time. The results show that this copolymer is an appropriate substitute for thiourea in copper electrorefining, and has significant flocculation effect on the floating slimes. When the graft copolymer was used as an additive combined with gelatin and bone glue, high-pure cathode copper can be obtained after electrolysis for 168 h at current density of 235 A/m2 and 65 ℃. The impurities of As, Sb and Bi in the cathode copper are 5.1×10-7, 1.24×10-6 and 6.9×10-7, respectively, which are much lower than those obtained by using the traditional additives of thiourea, gelatin and bone glue. The contents of As, Sb and Bi in the anode slimes are 5.12%, 4.04% and 1.01%, respectively, while those in the anode slime obtained using the thiourea as additive are 3.25%, 2.20% and 1.95%. The linear sweep voltammetry shows that the copolymer has polarization effect on Cu2+ reduction. In the meantime, the peak current density increases. When the copolymer was used with gelatin and bone glue, the polarization effect becomes weaker and peak current density decreases.
Key words: copper electrorefining; additive; gelatin-acrylamide graft copolymer; thiourea; gelatin; acrylamide
