A facile route to the value-added utilization of ludwigite ore: boron extraction and MxMg1-xFe2O4 spinel ferrites preparation

• Published in: Journal of cleaner production 2022-11, Vol.375, p.134206, Article 134206
• Main Authors: You, Jinxiang, Wang, Jing, Luo, Jun, Peng, Zhiwei, Rao, Mingjun, Li, Guanghui
• Format: Article
• Language: English
• Subjects: Ludwigite ore; Metal-doped magnesium ferrites; Oxidative roasting; Soda ash; Water leaching
• ISSN: 0959-6526; 1879-1786
• DOI: 10.1016/j.jclepro.2022.134206

The utilization of ludwigite ore is of strategic significance to China. Aiming to realize the comprehensive utilization of ludwigite ore, facile technique route was proposed to selectively leach boron and prepare single-phase metal-doped spinel ferrites via oxidative roasting-water leaching-magnetic separation. The synergistic formation mechanism of sodium borate and metal-doped magnesium ferrites was primarily investigated, and the roasting and leaching parameters on the boron leaching were optimized. The presence of Na2CO3 facilitates the formation and grain growth of ferrites during roasting, and at least 20 wt% Na2CO3 is needed to activate boron efficiently. As the insoluble magnesium borate transforms into soluble sodium borate, the water leaching ratio of boron reaches 95.97%. Subsequently, the high-purity single-phase metal-doped magnesium ferrites were prepared by magnetic separation from the water leaching residue. [Display omitted] •Oxidative roasting behavior of ludwigite ore in the presence of Na2CO3 was studied.•Different metal-doped ferrites were synthesized by oxidative roasting.•The water leaching ratio of boron reaches 95.97%.•The Zn-doped ferrite with a saturation magnetization of 51.37emu/g was obtained.•A novel process for value-added utilization of ludwigite ore was proposed.