中国有色金属学报(英文版)
Transactions of Nonferrous Metals Society of China
| Vol. 35 No. 11 November 2025 |
（1. State Key Laboratory of Advanced Metallurgy, University of Science and Technology Beijing, Beijing 100083, China;
2. School of Metallurgical and Ecological Engineering, University of Science and Technology Beijing, Beijing 100083, China）
Abstract:The loss pathways of Ni and Co during Al and Sc enrichment were analyzed in the HNO3 leach liquor of saprolitic laterite ore. Although over 99% of Al and Sc can be enriched, about 40% of Ni and Co are also lost. The adsorption of Al-Sc precipitate is an important cause of Ni and Co loss. Subsequently, the precipitation behavior of metal ions in the different nitrate solutions was studied. The results confirm that Ni2+ and Co2+ do not hydrolyze to form their respective hydroxides. Ni2+, Co2+ and Mg2+ can form composite hydroxides with precipitated Al(OH)3, decreasing the pH at which Ni2+ and Co2+ begin to precipitate, causing their co-precipitation loss. A high Mg2+ concentration enhances the formation of these composite hydroxides. Finally, titration curves for different nitrate systems were determined, further demonstrating the formation of Me-Al composite hydroxides and revealing a formation trend of Mg-Al > Co-Al > Ni-Al.
Key words: laterite ore; HNO3 leach liquor; metal loss; hydrolysis precipitation; composite hydroxide
