Chromite beneficiation process

Chromite gravity separation method

Chromite gravity separation is mainly based on the density difference between chromium minerals. Commonly used methods include shaking table separation and jig separation.

Shaking table sorting: It uses the longitudinal and transverse water flow on the shaking table surface to achieve sorting. It is mainly suitable for fine-grained chromite ore sorting and processing. The particle size range is generally 3-0.019mm.

Jig selection: It uses a jig, which is mostly suitable for processing coarse and medium-sized chromite ore. The general processing particle size range is 35-0.1mm, which can be The final product is obtained in one selection.

Magnetic separation of chromite

Because chromite itself has weak magnetic separation, magnetic separation can be used to complete the separation. Commonly used magnetic separation methods include weak magnetic separation and There are two strong magnetic separation methods.

Weak magnetic separation: It can effectively remove magnetite, increase the chromite-to-ferrite ratio of the concentrate, and further enrich and select qualified chromite concentrate products.

Strong magnetic separation: First use a medium magnetic separator to remove magnetite, and then use a strong magnetic separator to recover chromite and separate gangue minerals. It is mainly suitable for gravity separation. Micro-fine minerals that cannot be efficiently recycled.

Chromite flotation method

When the chromite ore is fine or in a fine particle state, gravity separation or magnetic separation cannot achieve ideal results, so flotation method is used. Anionic collector flotation and cationic collector flotation are commonly used for separation.

Anion collector flotation: It is necessary to fully disperse the slurry, selectively flocculate the minerals, and preferentially flotate the chromium minerals. Therefore, during grinding, the minerals must be fully dissociated, and alkali must be added to ensure the pH value of the slurry (pH=11.0~11.5). Afterwards, a dispersant must be added to form a stable dispersion system for the slurry, and then the dispersed slurry can be added to the Add selective flocculants to flocculate fine-grained gangue. However, care should be taken to prevent the formation of an anionic collector film on the flocculated gangue minerals.

Cationic collector flotation: Fine grinding operation is required to achieve monomer dissociation of minerals, but a large amount of slime will be produced, so pre-sliming should be carried out before flotation. operation, otherwise a large amount of chromite ore will be lost.