Magnetite beneficiation process

Single magnetic separation method

is mostly used to process sedimentary metamorphic magnetite (most of the ore is magnet), and its gangue minerals are mostly silicate minerals such as quartz or amphibole. Some contain more iron silicate. Usually:

When the grinding particle size is >0.2-0.3mm, one-stage grinding-magnetic separation process is often used;

When the grinding particle size is <0.2-0.3mm, two-stage grinding and magnetic separation processes are often used. Stage grinding-magnetic separation process;

If qualified tailings are separated by coarse grinding, the stage grinding-magnetic separation process will be used;

If a certain amount of surrounding rock is mixed into the ore Or when the ore contains a certain amount of single gangue minerals in the crushed products at all levels, a dry magnetic separator can be used for pre-selection before grinding;

If the low-grade, lean magnetite The coarse-grained dry magnetic separation tailing method is often used. If the grade is below 20.00% (ultra-poor magnetite), the ultra-fine crushing-wet magnetic separation tailing process can be used before grinding, that is, the ore is finely crushed to less than 5mm-3mm. , and then use a permanent magnet field magnetic separator for wet magnetic separation.

Weak magnetic-reverse flotation method

When the magnetite gangue contains silicate or carbonate minerals, accompanied by cobalt pyrite, chalcopyrite and phosphorus When removing stone, the weak magnetic separation-reverse flotation process can be used, that is, the weak magnetic separation process is used to recover iron, and then the sulfide or apatite, etc. are recovered through the reverse flotation process.

According to different chemical systems, especially the type of collector, the weak magnetic separation-reverse flotation process can be divided into weak magnetic separation-cation reverse flotation process and weak magnetic separation-anion reverse flotation process. Craftsmanship.

1. Weak magnetic separation - cation reverse flotation

This method uses starch as an inhibitor of magnetite and amines such as dodecylamine as a collector. The required The slurry temperature is low (above 25°C) and the slurry is neutral, which is especially suitable for processing magnet ores with high silicon content. This process has a single and simple reagent system, low flotation temperature, suitable for on-site application, simple and reliable operation, quick adjustment and change, and strong adaptability to process changes.

2. Weak magnetic separation - anion reverse flotation

The flotation foam of this method is not sticky, the index is relatively stable, and it has basically no corrosive effect on rubber, but the anion reverse flotation method uses There are many types of reagents, and the required flotation slurry temperature is higher (above 30°C). The slurry is alkaline, which is conducive to pipeline transportation and direct filtration of concentrates, but acid treatment is required before filtration. The weak magnetic separation-anion reverse flotation process is suitable for magnet ores containing more iron silicate minerals. Due to the selective activation of siliceous minerals and the suppression of iron minerals in strong alkaline media, the iron minerals The floatability is quite different from that of siliceous minerals, which improves the flotation selectivity. Therefore, high-quality iron concentrate can be obtained while low-grade tailings can be discarded, and it has good control over changes in the properties of the floating materials. Adaptability.