Copper smelter slag treatment by ammonia solution: Leaching process optimization

Abstract

The feasibility of copper smelter slag processing by ammonia solution treatment was investigated. The central composite rotatable design (CCRD) and approximation method were used to determine the optimum conditions of zinc and copper recovery to a solution. The experimental design was done at five levels of the four operating parameters which were the initial concentration of NH₃, the initial Cl^– ions concentration, leaching time and solid/liquid ratio. Two mathematical models describing dependence of metal recovery on the operating parameters were obtained. The models are successful in predicting the responses. It was found that optimal parameters for zinc and copper recovery are as follows (values for copper are given in brackets): initial

{\text{C}}_{\text{N}{\text{H}}_3}

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17.1% (19.9%), initial

C_{\text{C}{\text{l}}^{-}}

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160 g/L (160 g/L), leaching process duration 4.56 h (4.13 h), solid/liquid ratio 0.39 (0.53). The maximum Zn and Cu recoveries to solution, obtained experimentally under the conditions, are 81.16% and 56.48%, respectively.

Keywords

copper slag / ammonia solution / metal recovery / central composite design / optimization

References

[1] DavenportW G, KingM, ShlesingerM, BiswasA KExtractive metallurgy of copper [M], 2002, Oxford, Elsevier Science Ltd.

[2] JadhavU U, HochengH. A review of recovery of metals from industrial waste [J]. Journal of Achievements in Materials and Manufacturing Engineering, 2012, 54(2): 159-167

[3] SuklaL B, PandaS C, JenaP K. Recovery of cobalt, nickel and copper from converter slag through roasting with ammonium sulphate and sulphuric acid [J]. Hydrometallurgy, 1986, 16(2): 153-165

[4] HerrerosO, QuirozR, ManzanoE, BouC, VinalsJ. Copper extraction from reverberatory and flash furnace slags by chlorine leaching [J]. Hydrometallurgy, 2012, 49(12): 87-101

[5] BanzaA N, GockE, KongoloK. Base metals recovery from copper smelter slag by oxidizing leaching and solvent extraction [J]. Hydrometallurgy, 2002, 67(1): 63-69

[6] AltundoganH S, TumenF. Metal recovery from copper converter slag by roasting with ferric sulphate [J]. Hydrometallurgy, 1997, 44(1): 261-267

[7] ArslanC, ArslanF. Recovery of copper, cobalt and zinc from copper smelter and converter slags [J]. Hydrometallurgy, 2002, 67(1): 1-7

[8] AltundoganH S, BoyrazliM, TumenF. A study on the sulphuric acid leaching of copper converter slag in the presence of dichromate [J]. Minerals Engineering, 2004, 17(3): 465-467

[9] CarranzaF, IglesiasN, MazuelosA, RomeroR, ForcatO. Ferric leaching of copper slag flotation tailings [J]. Minerals Engineering, 2009, 22(1): 107-110

[10] ZhangY, ManR L, NiW D, WangH. Selective leaching of base metals from copper smelter slag [J]. Hydrometallurgy, 2010, 103(1): 25-29

[11] PeretrutovA A, ChubenkoM N, KimP P. Physicochemical properties of eutonic aqueous solutions of zinc and copper tetraammoniates in the range 293–323 K [J]. Russian Journal of Physical Chemistry A, 2009, 83(10): 1813-1815

[12] PeretrutovA A, ChubenkoM N, KimP P, YakuninY I. Combined solubility of copper and zinc oxides in ammoniaammonium solutions [J]. Russian Journal of Physical Chemistry A, 2009, 83(8): 1422-1425

[13] NadirovR K, SyzdykovaL I, ZhussupovaA K, UsserbaevM T. Recovery of value metals from copper smelter slag by ammonium chloride treatment [J]. International Journal of Mineral Processing, 2013, 124: 145-149

[14] BoxG E P, HunterW G, HunterJ SStatistics for experiments [M], 1978, New York, Wiley Interscience

[15] MontgomeryD CDesign and analysis of experiments [M], 2001, New York, John Wiley & Sons

[16] BieglerL T, GrossmannI E, WesterbergA WA note on approximation techniques used for process optimization [M], 1984, Pittsburgh, Carnegie Institute of Technology