中国有色金属学报(英文版)
Transactions of Nonferrous Metals Society of China
| Vol. 32 No. 1 January 2022 |
（1. Department of QC & SSP Audit, Projects & Development India Limited (Govt. of India U/T), PDIL Bhawan, A-14, Sector-1, Noida, Gautam Buddh Nagar, U.P – 201301, India;
2. Department of Fuel, Minerals and Metallurgical Engineering, Indian Institute of Technology (Indian School of Mines), Dhanbad, Jharkhand – 826004, India）
Abstract:An attempt has been made to investigate and optimize the recovery of Ni and Al through sulphuric acid (3.0-5.5 mol/L) leaching under different operating conditions. From the leaching experiments, it was possible to extract 98.5% of NiO and 40.7% of Al2O3 under the conditions of 5.5 mol/L H2SO4, reaction time of 4 h, solid-to-liquid ratio 0.2 g/mL, temperature of 358 K, particle size <100 μm, 200-250 r/min with 5.0 g catalyst dosage. The leached liquor Al was separated by selective crystallization using 1.4 mol/L KOH and Ni was separated by selective precipitation using 0.3 mol/L H2C2O4. From the studies, it is possible to recover around 97.9% of NiO having 98.3% purity, around 25% of Al2O3 was also recovered as alum-(K) having 99% purity and 14.7% of Al2O3 as a salt of Al-K-C2O4-SO4. Sulphuric acid was found to be a suitable leaching agent for selective leaching and it was also observed that alum-(K) can be selectively crystallized from sulphate solutions. The study also indicated the effective extraction and recovery of nickel and aluminium which were well supported by characterization studies using TG-DTA/DTG and XRD techniques.
Key words: spent catalyst; leaching; precipitation; crystallization; nickel; aluminium
