Study on the effect and mechanism of coarse magnetite on the flotation of fine-grained hematite

Abstract

Lean hematite ore is one of the refractory iron ores in China due to its fine crystal size, deep oxidation degree and complex mineral composition. With the deep mining of mine ore, the disseminated particle size of iron minerals is finer, and the ore properties are more complex and difficult to be separated. Therefore, the research on high-efficiency beneficiation technology of fine-grained lean hematite ore is the requirement and important direction of the development of refractory iron ore beneficiation. In this paper, the carrier flotation method is used to comprehensively recover hematite, and the addition of coarse-grained magnetite can effectively improve the recovery rate of fine-grained hematite. The flotation results show that when the ratio of magnetite to hematite is 1: 1, the recovery rate of iron ore can reach more than 96.34%, and the efficient recovery is realized. Based on the results of pure mineral test, the carrier flotation test of Anshan lean hematite ore was carried out. The results show that the reverse flotation concentrate product with TFe grade of 67.88% and total iron recovery of 84.81% can be obtained, and the TFe grade of the reverse flotation tailings is 24.20%. It can be seen that compared with the traditional process, the grade of carrier flotation tailings is 2.37 percentage points lower than that of the original reverse flotation tailings; the carrier reverse flotation process can effectively improve the recovery rate of iron concentrate. In addition, the theoretical analysis of carrier flotation was carried out by contact angle, zeta potential, mineral phase microscope, SEM and XPS. It was found that the collision probability between fine mineral particles and bubbles was low, which limited the recovery of fine mineral particles in the flotation process. Fine-grained hematite can be non-selectively attached to the carrier particles, thereby affecting the adsorption of starch on it, thereby improving the recovery rate of fine particles; The carrier reverse flotation can further improve the flotation efficiency by gravity and shear force. Carrier reverse flotation provides a new idea for effective recovery of iron ore.