The mineral raw materials are selected into the sorting operation after crushing operations, and the beneficiation operation is also the central part of the beneficiation process. Beneficiation is the process of separating useful minerals from gangue or separating useful minerals from each other, such as gravity separation, flotation, magnetic separation, electric separation, sorting and chemical separation. The following will be explained one by one.

Gravity

Gravity separation refers to the use of the proportion of mineral material particles in the medium flow to separate, including heavy medium selection, jigging selection, table selection, chute selection, etc.. Mainly used for separation of wolframite, cassiterite, gold, coarse grained iron and manganese ore, is also suitable for the separation of rare metals. Gravity separation applicable to a wide range of grain size, from hundreds of millimeters to less than a millimeter, low beneficiation costs, less pollution to the environment; at the same time, gravity separation is the most important method of coal preparation.

flotation

Flotation is the separation of water wettability (hydrophobicity or hydrophilicity) on the surface of various mineral raw materials. Froth flotation. Flotation usually can process materials less than 0.2 ~ 0.3mm, in principle, it can be used to choose various mineral materials, which is one of the most widely used methods. Flotation can also be used in the separation of intermediate products, ions in the solution (see ion flotation) and treatment of waste water.

magnetic separation

Magnetic separation is the use of different magnetic properties of mineral particles, in the uneven magnetic field in the separation. Strong magnetic minerals (magnetite and pyrrhotite) with weak magnetic field magnetic separator; weak magnetic minerals (hematite, siderite, ilmenite and wolframite, etc.) with strong magnetic separator separation.

The structure of magnetic separator cylinder type, belt type, ring type, disc type, roller type induction, the main development tendency is to solve the problem of magnetic separation recovery of fine weakly magnetic minerals.

Electric separation

Electrical separation is the use of the difference of electrical properties of mineral particles in high voltage electric field for sorting, mainly for sorting conductors, semiconductors and non conductor minerals. The electric separator can be divided into electrostatic separator, corona concentrator and composite electric field separator according to electric field; according to the electrification method of ore particles, the electric separator can be divided into contact electric separator, corona charged separator and charged electric separator.

Electric machine processing size range is narrow, low processing ability, raw materials should be dried, so the application is limited; but the cost is not high, good separation effect, less pollution; mainly used for selection of rough concentrate, such as separating scheelite, cassiterite, zircon, ilmenite, Jin Hongshi, tantalum niobium ore, monazite. Electrical separation is also used for classification and dust removal of mineral raw materials.

Picking

Picking includes hand picking and mechanical sorting, mainly used for pre selective crushing of waste rock. Hand selection is based on the external characteristics of minerals, and is manually selected, which is an ancient mineral processing method. Mechanical sorting includes light picking, X ray picking and radiation sorting.

Light sorting uses the differential selection of mineral optical properties; X ray sorting, the use of X rays to emit fluorescence characteristics selection; radioactive sorting, the use of uranium, thorium and other minerals of natural radioactive separation.

Chemical separation

Chemical separation refers to the separation and recovery of useful components by chemical methods or chemical and physical methods, and chemical concentrates are obtained by using the different chemical properties of minerals. This method is more adaptable than the usual physical mineral processing method and has good separation effect, but the cost is high. It is often used to treat mineral raw materials, intermediate products or tailings which are difficult to be processed or treated by physical mineral processing methods.

In addition, there are mineral materials in the inclined motion or collision, the friction coefficient and collision recovery coefficient are used to select other friction and bounce selection. There are many kinds of beneficiation methods in mineral processing, and users should choose the appropriate method according to their mineral properties.