Anshan City Magnetite Separation Project

The Anshan magnetite magnetic separation project is an important engineering practice that leverages the city's abundant iron ore resources and combines advanced magnetic separation technology to achieve efficient separation of low-grade ore. Multiple project cases demonstrate that by optimizing processes such as "stage grinding-magnetic separation," "weak magnetic + strong magnetic combined pre-selection," and "magnetic-float combined process," concentrate grade and recovery rate can be significantly improved, achieving cost reduction and efficiency improvement.

I. Typical Magnetic Separation Process Route and Technical Characteristics

1. Staged Grinding-Magnetic Separation Process
   For lean magnetite ore in the Anshan area, a process combining three-stage crushing, staged grinding, and multi-stage magnetic separation is adopted. For example, in the process designed by Yantai Xinhai for the Qianshan magnetite mine, magnetic pulley pre-selection increases the feed grade by 2%, and hydrocyclone classification and closed-circuit grinding control the particle size, ultimately achieving a concentrate grade of over 66% and a recovery rate exceeding 81%.
2. Weak Magnetic + Strong Magnetic Combined Pre-selection Process
   For extremely lean ore with an iron content of only 28.11%, a combined pre-selection process using a high-pressure roller mill followed by weak magnetic (250 mT) and strong magnetic (1000 mT) can increase the concentrate grade to 34.04% and remove 21.76% of coarse tailings in advance, significantly reducing the subsequent grinding and separation load and resulting in significant energy savings.
3. Magnetic-Flotation Combined Process (Weak Magnetic-Anion Reverse Flotation)
   To obtain high-grade concentrate (TFe≥69%), reverse flotation desilication is often introduced after magnetic separation. The "weak magnetic-strong magnetic-anion reverse flotation" process developed by Changsha Research Institute of Mining and Metallurgy has become a classic process for Anshan-type magnetite deposits and is widely used in beneficiation plants such as Qidaishan and Tiaojuntai, which can reduce the SiO₂ content to below 3%.

II. Key Equipment and Intelligent Supporting Systems

• Permanent Magnet Drum Magnetic Separator: Suitable for the recovery of coarse-grained, strongly magnetic minerals. Magnetic field strength exceeds 10,000 GS, with deep magnetic penetration, making it suitable for coarse pre-selection of Anshan-type magnetite.
• Vertical Ring High Gradient Magnetic Separator: Induction field strength can reach 20,000 Gauss, providing a high capture rate for -0.038mm micro-fine weakly magnetic minerals, ensuring separation accuracy in the fine grinding and selection process.
• Intelligent Control System: Includes remote monitoring, fault diagnosis, and PLC parameter control. Already applied in the Ansteel resource project, it has reduced the overall production line failure rate by 30%.