Magnetite is mostly blocked granular aggregation with high magnetism and wide distribution. According to the different species of iron ore, the magnetite can be divided into single magnetite and mixed magnetite iron ore. In general, the single magnetite separation process usually adopts the weak magnetic separation process, while the polymetallic magnetite iron ore and mixed magnetite iron ore are usually separated by the combined process consisting of a variety of separation methods, including magnetic separation process, flotation process, gravity separation process, magnetization roasting magnetic separation process, reduction roasting magnetic separation process.
One. Magnetite Separation Process
1. Single magnetite separation process
The vast majority of iron minerals in the single magnetite ore are magnetite, because the single magnetite ore has a simple composition, strong magnetism, easy to grind and easy to be separated, so the single magnetite separation process often adopts the weak magnetic separation process.
◆ When the grinding particle size is greater than 0.2mm, most magnetic separation plants usually adopt a one-stage grinding – magnetic separation process.
◆ When the grinding particle size is less than 0.2mm, the two-stage grinding-magnetic separation process is adopted us the single magnetite separation process;
◆ If the qualified tailings are separated in the rough grinding stage, the magnetite magnetic separation plants generally adopt the stage grinding-magnetic separation process;
◆ For the arid and water-deficient areas, the magnetite separation plant can use dry grinding–dry magnetic separation process;
◆ For the depleted rich magnetite iron ores or poor magnetite ores, the gangue can generally be removed by the dry magnetic separation process, and the concentrate can be obtained from the bulk rich ore by grinding and magnetic separation process.
In order to obtain high-grade concentrate, magnetite concentrate can be treated by reverse flotation or high-frequency fine screen. In addition, in order to improve the recovery rate, the tailings reprocessing process can be considered to further recover the magnetic minerals.