【Technology】Common iron ore beneficiation production line

Most of the poor iron ore resource quality is not high, and most of the ore is fine-grained strips, braided and scattered points, and even has a fine structure. Some are polymetallic symbiotic composite deposits, and some valuable minerals usually need to be finely ground to 200 mesh, accounting for 90% of the monomer separation, which brings difficulties to the operation of the beneficiation production line.

The characteristics of lean iron ore resources determine that its development and utilization are different from other minerals. The amount of mining work is large, the output value is low, the profit is small, and the capital utilization rate is low.

Several common types of iron ore beneficiation production lines

(1) Mineral dressing of magnetite quartzite

Magnetite Quartzite, iron ore, mainly contains magnetite and quartz. According to the magnetism of magnetite quartzite, the magnetic separation of magnetite and quartz is usually used for magnetic separation.

The separation process of magnetite and quartzite is through three to four stages of crushing to 25-15mm, or through one stage of crushing to 350-250mm, combined with ball milling (gravel crushing) for three stages of fine grinding and enters multistage magnetic separation. The magnetite quartzite beneficiation process is characterized by a stage grinding and magnetic separation process in order to discharge monomer gangue in one stage and reduce the amount of grinding in the next stage.

(2) Beneficiation of magnetite ore

Magnetite contains small amounts of sulfide minerals and is associated with non-ferrous metals such as cobalt, nickel and vanadium. Magnetic susceptibility is similar to magnetite quartzite. According to the embedded characteristics of particle size, it can be divided into coarse particle, fine particle, fine particle and extremely fine particle size ore.

According to the physical properties of magnetite, the most effective beneficiation method is to recover magnetic minerals by magnetic separation and related sulfide minerals by flotation. The sorting process is mainly two to four stages of crushing, and one or two dry magnetic separations are carried out during the crushing process to select medium or subdivided products.

In order to further in-depth product selection, after two to three stages of fine grinding, two to five times of wet magnetic separation, using a combined process of magnetic separation-flotation or flotation-magnetic separation to obtain the final iron concentrate product to improve While iron concentrate is in taste, it can also recycle related minerals into corresponding concentrate products, as well as desulfurization of concentrates.

Magnetite ore grinding has a coarser particle size and less muddy particles. Typically, magnetic separators are used for deashing. The beneficiation plant that chooses magnetite operates according to the full cycle water supply process, and the utilization rate of cycle water is 75%~85%.

 (3) Beneficiation of hematite and hematite-magnetite ore

The beneficiation production line of hematite currently adopts magnetic separation-gravity separation process, magnetic separation-flotation process or gravity separation-magnetic separation-flotation process. Some plants first use the gravity separation method to recover hematite. Magnetite is recovered from reselected tailings by magnetic separation; it can also be selected by flotation and electroporation, or by fine screening before the final stage of sorting.

The magnetic separation-gravity separation process first recovers magnetite through weak magnetic field magnetic separation, and then recovers hematite from the magnetic separation tailings by gravity separation; the magnetic separation-flotation process uses flotation to separate the main red iron concentrate The process is to recover coarse hematite and magnetite by gravity separation, and to recover fine magnetite by magnetic separation.

For dense crystalline red-magnetite quartzite, gravity separation methods are widely used to separate coarse-grained ores, and strong magnetic separation or flotation to separate fine-grained ores.

The beneficiation production line of hematite can use washing, gravity separation, flotation, magnetic separation and roasting magnetic separation methods, or flotation and electric separation as selection operations, and different types of ore processing processes can be formed according to different ore properties.

Resuspensions are used for beneficiation when coarse or lumpy ore is mixed into lean material. Some ore concentrators use ore beneficiation for granular ore, gravity separation of medium and fine ores with spiral concentrators, or magnetic separation with strong magnetic separators. Fine-grained quartz black rocks are processed by flotation or roasting magnetic separation.