Mineralogical Analysis of Factors Affecting the Grade of High-Gradient Magnetic Separation Concentrates and Experimental Study on TiO2 Enrichment Using ARC

High-gradient magnetic separation is a key step in the pre-concentration of ilmenite before flotation, particularly in the gravity separation process. However, as the amount of weakly magnetic gangue minerals increases, the grade of the coarse concentrate from high-gradient magnetic separation decreases. This paper investigates the mineralogical factors affecting the enrichment efficiency of high-gradient magnetic separation. Additionally, a newly developed stirred fluidized bed device, an agitated reflux classifier (ARC), was successfully applied to remove weakly magnetic gangue minerals that are difficult to separate by high-gradient magnetic separation (HGMS). For low-grade ilmenite with a feed grade of 3.97%, a combined process of magnetic separation and gravity separation was employed, achieving a concentrate with a grade of 16.50% and a recovery rate of 54.11%. This concentrate meets the requirements for flotation feed. This study provides a new approach for the beneficiation of low-grade ilmenite.