Method for recovering rare earth metals from solid minerals and/or by-products of solid mineral processing
The invention relates to the technology of recovery of rare-earth elements form both solid fossil and technology-related materials obtained by means of their target-oriented processing. Rare-earth elements recovery method include the acid leaching of ground to less than 100 μm solid fossil and technology-related materials with the mixture of sulphuric and nitric acid at ratio from 6:1 to 1:1 mass parts, at the concentration in mixture of acids less than 15 wt. % at liquid/solid phases ratio of L:S from 2:1 to 6:1 mass parts. During the leaching operation progress the vacuum-impulse action is conducted during all operation of transferring of rare-earth elements compounds into a solution and obtaining of a precipitate of remained solid fossil and technology-related materials. The obtained precipitate of solid fossil and technology-related materials is separated from leaching solution. Separation of rare-earth elements from leaching solution is conducted using ion-exchange filter or membrane filter.
1. A method of recovery of rare-earth elements from solid fossil and/or technology-related materials containing rare-earth elements, comprising a acid leaching of compounds of rare-earth elements from materials with a solution of mixture of sulphuric and nitric acid while stirring the leaching solution and transferring of rare-earth elements compounds into the solution and obtaining of insoluble precipitate of remaining solid material, a separation of insoluble precipitate from the leaching solution and recovery of compounds of rare-earth elements from the leaching solution, wherein prior to acid leaching a grinding of material particles is conducted to a size of less than 100 μm, and the leaching operation is conducted at simultaneous vacuum-impulse action with a ratio in mixture of sulphuric and nitric acids from 6:1 to 1:1 mass parts at a concentration in mixture of acids less than 15 wt. % at liquid/solid phases ratio (L:S) from 2:1 to 6:1 mass parts.
2. Method of claim 1 , wherein the rare-earth elements recovery from leaching solution is perforated by passing leaching solution through a cation-exchange filter.
3. Method of claim 1 , wherein the rare-earth elements recovery from leaching solution is performed by passing leaching solution through a membrane filter.