中国有色金属学报(英文版)
Transactions of Nonferrous Metals Society of China
| Vol. 23 No. 10 October 2013 |
（1. CSIR- Institute of Minerals and Materials Technology, Bhubaneswar-751 013, India;
2. Academy of Scientific and Innovative Research (AcSIR), Anusandhan Bhavan, Rafi Marg, New Delhi-110001, India）
Abstract:The recovery of nickel from spent nickel catalyst for the preparation of nickel hydroxide was studied. Nickel was extracted from the spent catalyst by acid leaching with 1 mol/L sulfuric acid at 90 °C. Purified nickel solution was used in the preparation of nickel hydroxide. Three different methods, namely urea hydrolysis, conventional, and hydrothermal methods, of precipitation using NaOH were employed to get various nickel hydroxides samples named as Ni(OH)2-U, Ni(OH)2-C, and Ni(OH)2-H, respectively. Hydrothermal treatment induced better crystallinity in the Ni(OH)2 compared with conventional method. Both Ni(OH)2-C and Ni(OH)2-H samples have mixed phases of b-Ni(OH)2 and a*-Ni(OH)2×0.75H2O phases, whereas Ni(OH)2-U has only a*-Ni(OH)2×0.75H2O. TEM image of Ni(OH)2-U sample shows rod-like Ni(OH)2 structures. Among all, Ni(OH)2-U shows the best electrochemical activity.
Key words: spent nickel catalyst; fibrous nickel hydroxide; recovery
