ZnO nanorods were synthesized by direct precipitation method from zinc ammonium chloride solutions. Firstly, the Taguchi method based on orthogonal array design (OAD) was used to maximize zinc extraction from zinc cathode melting furnace slags (ZCMFSs). The optimum conditions for the preparation of precursor were found to be t(4): 70 min, T-5: 80 degrees C, (S/L)(2): 40 g/L, R-3: 500 rpm, and C-4: 25 wt% and thus, the dissolution percentage of Zn in ammonium chloride media was obtained 94.61%. Dilution and cooling precipitation methods were used to synthesize ZnO nanorods. Productions were characterized by XRD, FESEM and UV-Vis spectroscopy to evaluate phases, crystalline size and optical properties of nanorods. Particle sizes were found 68 and 113 nm in diameter for dilution and cooling precipitation methods, respectively. BET method was used to determine specific surface area of the nanorods which achieved 17.85 and 9 m(2)/g for dilution and cooling precipitation methods, respectively. (C) 2013 Elsevier Ltd. All rights reserved.