Centrifugal extraction machine production and separation of rare earth elements
This article mainly from the original ore mining, introduced centrifugal extraction machine production and separation of rare earth elements and refining process.
Rare earth elements is a diversified market, it is 15 rare earth elements and yttrium, scandium and its various compounds from chloride 46% purity and 99% of single rare earth oxides and rare earth metal, has a variety of purposes.
Combined with related compounds and mixtures, countless products.
a, rare earth ore dressing processing is the use of various mineral composition of ore of the physical and chemical properties of differences between different processing method, using different mineral processing technology, different mineral processing equipment, the enrichment of useful minerals in the ore, removal of harmful impurities, and the machining process of the separation of the gangue mineral.
2, rare earth smelting method there are two kinds of rare earth smelting method, namely the pyrometallurgy and hydrometallurgy.
In this only to hydrometallurgy is presented in rare earth smelting method.
wet metallurgy chemical metallurgy way, most of the whole process in solution, the solvent, such as the decomposition of rare earth concentrate single rare earth metal, rare earth oxides, rare earth compound, the separation and extraction process is the precipitation and crystallization, REDOX, chemical separation processes such as solvent extraction, ion exchange process.
Is now more common organic solvent extraction, it is an industrial separation of high purity single general process of rare earth elements.
Hydrometallurgy process complex, high purity products, the production of finished product application is wide.
now in the production of rare earth separation methods (
(fractional step method,
Fractional crystallization method, grading precipitation and oxidation-reduction method)
Ion exchange method;
hydrometallurgy rare earth smelting method.
is the use of fractional step method, and to the difficulty of the compounds are dissolved in the solvent (
The difference for separation and purification.
Operation procedures of the method is: will contain two kinds of rare earth element compounds with suitable solvent dissolves, heating concentration in the solution part of element compounds analysis (
Crystallization and precipitation)
Deposition, smaller solubility of rare earth elements have been enriched, the solubility of larger enrichment of rare earth elements in solution.
Ion exchange method ion exchange method has the advantage of an operation can be multiple elements to be separated.
But also can get high purity products.
The downside of this approach is not continuous processing, a long operating cycle time, and the resin regeneration, exchange, consumption of the cost is high, so this was the main method of separation of a large number of rare earths has retired from the main separation method, and replaced by solvent extraction.
Solvent extraction do not use organic solvents from its phase miscibility in aqueous solution, the method is called by extraction and separation of extract liquid organic solvent -
Liquid-liquid extraction, solvent extraction for short, it is a kind of substance from a liquid transferred to another mass transfer process of the liquid phase.
solvent extraction method of the extraction process with fractional precipitation, fractional crystallization and ion exchange separation method, compared with good separation effect, large production capacity, to facilitate rapid continuous production, easy to realize automatic control and so on a series of advantages, thus gradually became the main method of separation of a large number of rare earths.
solvent extraction of major separation equipment have centrifugal extraction machine, used in the purification of rare earth extraction agent has: represented by acid phosphate ester cation extractant P204, P507, represented by amine N1923 anion exchange fluid and represented by the TBP, P350 neutral phosphate ester solvent extraction agent.
The viscosity and weight of the extraction agent is very high, and the water is not easy to separate.
Usually with kerosene and solvent to dilute with it.
extraction process in general can be divided into three main stages: extraction, washing, stripping.
The basis of extraction separation of light rare earth element H_3AOH system [