Performance assessment of an innovative precise low-intensity magnetic separator

Abstract

An innovative precise low-intensity magnetic separator (PLIMS) was developed for recovering low-grade magnetite. The effects of the key parameters on the separation performance of the PLIMS in recovering magnetite were investigated. The results indicated that the drum rotation speed and feed particle size played major roles in enhancing the grade of the concentrate and the recovery. Additionally, the performances of the PLIMS and selected conventional low-intensity drum magnetic separators (CLIMSs) and Davis tube testers (DTTs) were compared. The comparison revealed that the performance of the PLIMS was consistent with that of the DTT in terms of the grade of the concentrate and the recovery. In addition, the PLIMS had a higher iron grade with fewer gangue particles and higher recovery compared with the CLIMS.For the PLIMS, the remnant flux density of the magnet assembly was designed to gradually increase from low to high along the flow direction of the slurry. In the entire magnetic separation process, the magnetic force acting on the captured magnetic particles is always the most minor magnetic force required to achieve precise magnetic separation, which results in improved selectivity. Furthermore, the advantage of the PLIMS is that seven concentrates can be obtained by one magnetic separation. Therefore, the newly developed PLIMS simplifies the magnetic separation process and produces multiple products, and the grade of the concentrate can be flexibly controlled. It has a high recovery and can create various high-, medium-, and low-grade concentrates.