화학공학소재연구정보센터
Powder Technology, Vol.356, 170-176, 2019
Insight into effect of CaCO3 on reduction roasting of fine-grained silicate type iron oxide ore and its application on Fe separation and recovery
To solve the problem of processing of refractory iron oxide ore resulted from its fine-grained disseminated structure, in this paper, an improved technology was innovatively proposed, which consisted of three stages of reduction roasting-acid leaching followed by magnetic separation, and CaCO3 was introduced during roasting process. Mechanism analyses indicated that kaolinite, a major gangue in ore, can be thermally dehydrated to amorphous metakaolin during roasting process, and CaCO3 can in part react with metakaolin-converting the stable kaolinite gangue mineral into acid-soluble Ca3Al2(SiO4)(3), and subsequently Ca3Al2(SiO4)(3) was selectively removed by acid leaching process. Moreover, the presence of CaCO3 can also improve the gathering state of Fe-rich particles, which is beneficial for magnetic separation. Iron concentrate obtained via the proposed technology contained 53.73% Fe, 9.02% Mn, 7.51% Al, and 2.46% Si, with a Fe recovery ratio of 88.20%, which surely meet the iron ore quality requirement of steel and iron industry. (C) 2019 Published by Elsevier B.V.