Abstract:A clean route was developed to convert flue dusts of secondary copper smelters into value-added products. The process consists of microwave-assisted alkaline leaching, purification and electrolysis. Initially, 83% (mass percent) Zn is dissolved in 200 g/L NaOH under microwave radiation (4 cycles of 30 s), whereas most of Cu is left in the residue. The rates of zinc recovery are significantly higher under microwave conditions as compared to those observed with conventional leaching. Furthermore, a better zinc selectivity and lower NaOH consumption are obtained. Then, the purification by adding zinc powders is carried out to reduce the Pb and Cu to low levels (lower than 100 mg/L). Subsequently, ultrafine Na2S are produced by electrolysis and the best performance occurrs at reaction temperature of 35 ℃, current density of 1 000-1 500 A/m2 with a solution composition of 30-40 g/L Zn2+ and 180-220 g/L NaOH. The products were characterized by SEM, XRD and Malvern laser particle size analyzer. The clean method also promises to treat other industrial wastes containing Zn due to its low cost and simple design.
[1]Dvorak, P.and Jandova,J. Zinc recovery from chloride-bearing galvanizing waste[J].Acta. Metall. Slovaca, 2006, 12(1):90-94
[2]Ju, S.H.,Zhang,YF.,Zhang,Y.,Xue,P.Y.,and Wang,Y.H. Clean hydrometallurgical route to recover zinc,silver,lead,copper,cadmium and iron from hazardous jarosite residues produced during zinc hydrometallurgy[J].J. Hazard. Mater., 2011, 192(2):554-558
[3]胡慧萍, 谢丽芳, 陈启元等.碱法浸出含锌废催化剂制备硫化锌[J].有色金属冶炼部分, 2012, 42(1):42-45
[4]范金, 范滨.含锌废脱硫催化剂的合理利用[J].黑龙江石油化工, 1998, 9(1):15-17
[5]Zhao, Y.C.,and Stanforth,RProduction of Zn powder by alkaline treatment of smithsonite Zn-Pb ores[J].Hydrometallurgy, 2000, 56(2):237-249
[6]Pinto, I.S.S.,and Soares,HM.V.M. Recovery of molybdates from an alkaline leachate of spent hydrodesulphurisation catalyst–proposal of a nearly-closed process[J].J. Cleaner Prod., 2013, 52(1):481-487
[7]Sharifi B, Mojtahedi M, Goodarzi M, et al.Effect of alkaline electrolysis conditions on current efficiency and morphology of zinc powder[J].Hydrometallurgy, 2009, 99(11):72-76
[8]王鹏, 赵芳霞, 张振忠.直流电弧等离子体蒸发法制备超细锌粉[J].中国有色金属学报, 2011, 21(9):2236-2241
[9]Liu, Q, Zhao, Y.C. Production of zinc and lead concentrates from lean oxidized zinc ores by alkaline leaching followed by two-step precipitation using sulfides[J].Hydrometallurgy, 2011, 110(1-4):79-84
[10]Zhao, Y.C.,and Stanforth,RIntegrated hydrometallurgical process for production of zinc from electric arc furnace dust in alkaline medium[J].J. Hazard. Mater., 2000, 80(1-3):223-240
[11]Oustadakis, P.Tsakiridis,PE.,Katsiapi,A.,and Agatzini-Leonardou,S. Hydrometallurgical process for zinc recovery from electric arc furnace dust (EAFD). Part I: Characterization and leaching by diluted sulphuric acid[J].J. Hazard. Mater., 2010, 179(1-3):1-7
[12]Ren, X.L.,Wei,QF.,Hu,S.,and Wei,S.J. The recovery of zinc from hot galvanizing slag in an anion-exchange membrane electrolysis reactor[J].J. Hazard. Mater., 2010, 181(1-3):908-915
[13]Trung, Z.H.,Kukurugya,F,Takacova,Z.,Orac,D.,Laubertova,M.,Miskufova,A.,and Havlik,T. Acidic leaching both of zinc and iron from basic oxygen furnace sludge[J].J. Hazard. Mater., 2011, 192(3):1100-1107
[14]Zeng, L.and Cheng,CY. Recovery of molybdenum and vanadium from synthetic sulphuric acid leach solutions of spent hydrodesulphurisation catalysts using solvent extraction[J].Hydrometallurgy, 2010, 101(3-4):141-147
[15]Guresin, N.and Topkaya,YA. Dechlorination of a zinc dross[J].Hydrometallurgy, 1998, 49(1-2):179-187
[16]Frenay, J.Ferlay,S,and Hissel,J. Zinc and lead recovery from EAF dusts by caustic soda process[J].Electric Furnace Proceedings, Treatment Options for Carbon Steel Electric Arc Furnace Dust. Iron Steel Soc., 1986, 43(1):171-175
[17]Gurmen, S.and Emre,MA laboratory-scale investigation of alkaline zinc electrowinning[J].Miner. Eng., 2003, 16(6):559-562
[18]St-Pierre, J.and Piron,DL. Electrowinning of zinc from alkaline solutions at high current densities[J].J. Appl. Electrochem., 1990, 20(1):163-165
[19]Hua Y, Lin Z, Yan Z.Application of microwave irradiation on quick leach of zinc silicate ore[J].Minerals Engineering, 2002, 15(6):451-456
[20]Krishnan, K.H.,Mohanty,DB.,and Sharma,K.D. The effect of microwave irradiations on the leaching of zinc from bulk sulphide concentrates produced from Rampura–Agucha tailings[J].Hydrometallurgy, 2007, 89(3-4):332-336