Differences in Early Rejection of Gangue for Low-Grade Iron Ores with Different Textures from HPGR

ABSTRACT

The ore texture determines the proportion of the early rejection of gangue of the low-grade iron ores. However, a detailed study of the early rejection of gangue for low-grade iron ores with different textures is still highly desirable. In this study, three types of low-grade iron ores with different grain sizes were crushed to −3 mm by a high-pressure grinding roller (HPGR). Mineral Liberation Analyzer (MLA) and dry magnetic separation tests were performed on the resulting products. The MLA test results showed that the gangue in fine-grained iron ores was more difficult to liberate than in coarse-grained iron ores. The dry magnetic separation tests indicated that only 15.23% of gangue could be rejected for fine-grained iron ores, which was much lower than that of coarse-grained iron ores. Liberation analysis revealed that a large proportion of the gangue contained only a small amount of valuable iron oxide minerals. By returning the middling from dry magnetic separation to HPGR for crushing again, the gangue rejection percentage for fine-grained iron ore increased to 33.56%. These results demonstrate that liberation studies can help improve the efficiency of early rejection of gangue.

KEYWORDS:

• Low-grade iron ores
• early rejection of gangue
• grain size
• dry magnetic separation
• HPGR

Acknowledgment

The authors would like to acknowledge Chengdu Leejun Industrial Co. Ltd. for the equipment support. In addition, the authors gratefully acknowledge the financial support of the National Natural Science Foundation of China (Grant Nos. 52174239).

Disclosure statement

The authors declare that they have no known competing financial interests or personal relationships that could have appeared to influence the work reported in this paper.

Credit author statement

Keqiang Chen: Methodology, Validation, Investigation, Writing – Original Draft, Writing – Review & Editing.

Wanzhong Yin: Conceptualization, Funding acquisition, Writing – Review & Editing.

Additional information

Funding

The work was supported by the National Natural Science Foundation of China [Grant Nos. 52174239].