Red mud is the waste residue of high temperature and high alkali pollution discharged from the industrial production of alumina. The red mud deposited not only occupies a lot of land, but also causes environmental pollution.Red mud usually contains a large amount of iron oxide mineral. As the world’s fourth largest producer of alumina, China emits millions of tons of red mud every year, but the comprehensive utilization rate is less than 15%, causing serious waste of resources and environmental pollution.

    Generally, red mud has a high alkalinity, a pH value greater than 12, and contains 7%-40% iron. Low-grade red mud can be magnetized and calcined, while high-grade red mud can be directly recycled iron ore by magnetic separation using SLon magnetic separator.Baeyer method was used to extract aluminum from a bauxite mine in Shandong province, and the total iron grade of red mud tailings was about 27%. SLon vertical ring pulsating high-gradient magnetic separator was used to directly recycle iron ore. The iron grade of concentrate was about 50%, the iron recovery rate was 40%, and the annual recovery rate of iron concentrate was more than 500,000 tons, which significantly improved economic benefits and secondary resource utilization rate.

    SLon magnetic separators have been applied to red mud separation in pingguo Aluminum, Jinan Steel, Guangxi Bce, Chinalco group, Shanxi Luliang and many other places, with good indicators.