Individual enrichment of manganese and iron from complex refractory ferromanganese ore by suspension magnetization roasting and magnetic separation

Abstract

Owing to its complex characteristics, the large-scale utilization of ferromanganese ore is limited by the traditional processes. In this study, suspension magnetization roasting and magnetic separation technology was proposed, and the thermodynamics, phase and magnetic transformation, and microstructure evolution of the main minerals were systematically investigated during roasting. Results show that iron concentrate with iron grade of 68.31% at a recovery of 96.34% can be obtained in the magnetic separation concentrate, and manganese concentrate with manganese grade of 33.70% at a recovery of 86.83% can be obtained in magnetic separation tailings under optimum conditions. Pyrolusite and braunite were reduced to weak magnetic manganosite, and weak magnetic hematite was selectively transformed into strong magnetic magnetite. Many cracks appeared in the ores owing to the multiple reduction and dehydration reactions of ferromanganese ore, which was favorable for grinding and separation of manganese and iron.