(中南大學 冶金與環(huán)境學院，長沙 410083)
摘 要: 采用過氧化合物為引發(fā)劑，以明膠和丙烯酰胺為原料合成得到明膠-丙烯酰胺接枝共聚物(PGAM)，并將PGAM作為銅電解添加劑應用于銅電解精煉。結果表明：PGAM能夠替代硫脲用作銅電解添加劑，且對電解液中的漂浮陽極泥具有很好的絮凝作用。使用PGAM、明膠和骨膠作為添加劑時，在電解液溫度為65 ℃、電流密度為235 A/m2的條件下，電解168 h后，所得高純陰極銅中As、Sb和Bi含量分別為5.1×10-7、1.24×10-6、6.9×10-7，遠低于使用硫脲、明膠和骨膠作為添加劑時所得陰極銅中相應雜質(zhì)含量。電解所得陽極泥中，As、Sb和Bi含量分別為5.12%、4.04%和1.01%；而硫脲、明膠和骨膠為添加劑時，陽極泥中As、Sb和Bi含量分別為3.25%、2.20%和1.95%，表明PGAM有利于電解液中As和Sb的沉降。線性掃描伏安測試表明：PGAM在Cu2+還原過程中起極化作用，提高了Cu2+還原峰電流密度；與明膠和骨膠共同使用時，其極化作用減弱，峰電流密度降低。
關鍵字: 銅電解精煉；添加劑；明膠-丙烯酰胺接枝共聚物；硫脲；明膠
（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
