According to the difference in the physical and chemical properties of rare earth minerals and associated gangue and other minerals, the following methods are commonly used for ore beneficiation:
1. Radial beneficiation
The main use of rare earth minerals in ore and gangue minerals in the different content of cerium, using γ-ray irradiation concentrator, the rare earth minerals and gangue minerals separated. Radiation ore dressing method is mostly used for pre-selection of rare earth ore. At present, this method is not widely used in the industry.
2. Gravity ore dressing
The use of rare earth minerals and gangue mineral density different sorting. Commonly used re-selection equipment cone concentrator, spiral concentrator, shaker and so on. Re-election is mainly used to separate rare earth minerals from gangue minerals such as low-density quartz and calcite so as to achieve the purpose of pre-enrichment or obtaining of rare-earth concentrates. Re-election is widely used in the production of seashore placers; it is sometimes used as a method of pre-enrichment in the beneficiation of rare earth veins.
3. Magnetic Separation
Some rare earth minerals have weak magnetic properties. They can be used with different susceptibilities of associated gangue and other minerals. Magnetic separators with different magnetic field strengths are used to separate rare earth minerals from other minerals. In the beneficiation of seashore sand mines, weak magnetic separation is often used to separate ilmenite from monazite; strong magnetic separation can also be used to separate monazite from zircon and quartz. In the beneficiation of rare earth vein minerals, in order to simplify the flotation process and save flotation chemicals, strong magnetic separation is sometimes used to enrich rare earth minerals. With the continuous development of strong magnetic technology, strong magnetic separation will be more and more widely used in the beneficiation process of rare earth ore.
Using the difference in surface physical and chemical properties of rare earth minerals and accompanying minerals, floatation is used to separate them from associated gangue and other minerals to obtain concentrates. It is currently the main ore dressing method widely used in the production of rare earth minerals. Mountain Pass rare earth mines in the United States use floatation to produce rare earth concentrates. In the production of seashore sand mines, rare earth concentrates are often obtained from heavy sands by flotation after re-sanding to obtain heavy sands.
5. Electric selection method
Rare-earth minerals are non-good conductors that can be used to differentiate their conductive properties from their associated minerals. They are separated by electro-selective methods from those with good conductivity. Electric electrification is often used in the selection operation of beach sand heavy sand.
6. chemical ore dressing method
Rare earth deposits are adsorbed on kaolin or clay by ionic form. It can make full use of the characteristics of rare earth ions which are soluble in sodium chloride or ammonium sulfate solution. The rare earth minerals of fluorocarbon, which are soluble in acid or at high temperature, can be preconcentrated in advance by flotation, and then purified by chemical ore dressing (acid leaching or high temperature roasting).