Research on red mud treatment by a circulating superconducting magnetic separator

Area of Science:

• Environmental Science
• Materials Science
• Chemical Engineering

Background:

• Red mud (RM) generation poses significant environmental challenges due to large accumulation volumes.
• Effective management of RM requires innovative solutions for waste reduction and resource recovery.
• Iron-rich fraction separation offers a cost-effective approach to mitigate RM disposal issues.

Purpose of the Study:

• To investigate the efficiency of a novel circulating high-gradient superconducting magnetic separator for iron-rich RM separation.
• To analyze the impact of steel wool matrix parameters on the separation process.
• To characterize the separated iron-rich RM fractions.

Main Methods:

• Development and implementation of a circulating high-gradient superconducting magnetic separator using steel wool in circulating boxes.
• Magnetic separation experiments on raw RM to recover iron-rich fractions.
• Analysis of separated fractions, including iron content, particle size distribution, and microscopic examination.

Main Results:

• Successfully separated 25% (w/w) of iron-rich RM fractions with a 65% iron grade from raw RM (56% iron content).
• Demonstrated that steel wool matrix parameters critically influence separation efficiency; finer steel wool improved recovery but reduced concentrate grade.
• Microscopic analysis confirmed enrichment of opaque mineral particles in the concentrate, and particle size analysis indicated entrapment of larger particles in the matrix.

Conclusions:

• The developed superconducting magnetic separator is effective for separating iron-rich fractions from red mud.
• Optimizing steel wool characteristics is crucial for balancing iron recovery and concentrate grade.
• This method provides a viable route for reducing RM disposal volume and recovering valuable iron resources.