废铜包铁针NH3-（NH4）2SO4-H2N（CH2）2NH2体系隔膜电解回收铜

Copper recovery from scrap copper coated iron needle via membrane electrolysis in NH3-（NH4）2SO4-H2N（CH2）2NH2 system

以电子加工行业产出的废铜包铁针为阳极,以不锈钢板为阴极,采用单因素试验法优化NH3-(NH4)2SO4-H2N(CH2)2NH2体系隔膜电解回收铜工艺。结果表明:在阴极液组成为NH3·H2O 4.5 mol/L、(NH4)2SO4 1 mol/L、Cu(Ⅱ)30 g/L、乙二胺0.4 mol/L以及阴极电流密度为350 A/m2的条件下隔膜电解12 h后,在阴极可以得到表面光滑平整的阴极铜板,阴极铜纯度99.95%。由于部分阳极铜以+1价溶解于电解液中,使得实际隔膜电解回收废铜包铁针时阴极电流效率达到106%(以+2价铜电化当量计算),而阳极电流效率则为126%,脱铜后得到的铁针品位为99.3%。

Using scrap copper coated iron needle as anode and stainless steel plate as cathode,the membrane electrolytic recovery of copper from scrap copper coated iron needle viaNH3-(NH4)2SO4-H2N(CH2)2NH2 system was optimized by single factor test.The experimental results show that,when the catholyte composition is NH3·H2O 4.5 mol/L,(NH4)2SO4 1mol/L,Cu(Ⅱ)30 g/L,ethylenediamine 0.4 mol/L,and the cathode current density is 350 A/m2,a smooth cathode copper plate can be obtained at the cathode for 12 h electrowinning,and the grade of resultant cathode copper is 99.95%.The cathode current efficiency is 106%(calculated at+2 valence copper electrification equivalent),while the anode current efficiency is 126%,because some anode copper dissolves in the electrolyte at+1 valence.The grade of iron needle obtained after copper removal is 99.3%.