Production of Rare Earth Metals by Fused Salt Electrolysis
Rare earth metals in their pure elemental form are not found in nature, thus there is a need for an efficient method for producing them. Fused salt electrolysis, where a mixture of molten salts and rare earth metals are used in electrochemical cells, is one of the most efficient methods employed for extracting rare earth metals.
Fused salt electrolysis is a complex process that is used to produce both ionic and elemental forms of rare earth metals. In this process, a salt melt composed of compounds such as fluoride, chloride, nitrate, sulfate, borate and carbonate salts are placed into an electrolytic cell and then heated to melting point. Rare earth metals in their oxidised form are then added to the salt melt and then an electric current is introduced which causes the reduction of the rare earth metals to the elemental form. This process can also be used to separate and purify the different rare earth metals from each other and also to create mixtures of rare earth metals.
The electrolysis process uses a range of different operational parameters such as the temperature, electrical current, cell type and reactant material, which must all be carefully monitored to ensure the successful production of rare earth metals. The temperature must be strictly maintained to ensure that the salts remain in liquid form throughout the process and electric current must be carefully controlled in order to allow for the optimum reduction of the rare earth metals. The cell type used will depend on the type of reaction that needs to occur, and depending on the reactant material, different reactants may be required in order to catalyse the reactions within the cell.
The purity of the rare earth metals produced by fused salt electrolysis can also be controlled, with highly pure rare earth metals being produced. This is achieved through carefully controlling the reactants and parameters of the electrolysis process, as well as by adding certain purifying agents such as fluoride and nitrate to the electrolytic cell. The purity achieved can vary, however the most common purity of the rare earth metals produced is 99.9%.
The efficiency of fused salt electrolysis differs depending on the rare earth metals being extracted, with higher efficiency being realised when extracting certain rare earth metals such as lanthanum and cerium, while lower efficiency is seen when extracting rare earth metals such as yttrium and terbium. The cost involved in producing rare earth metals using fused salt electrolysis is relatively low, making this an attractive option for the production of these metals.
In conclusion, fused salt electrolysis is an efficient and cost effective method for producing rare earth metals in their elemental form. By carefully controlling the parameters of the electrolytic process, highly pure rare earth metals can be produced, which can then be used for a range of different applications. The efficiency and cost of this process make it an attractive option for producing these rare and versatile metals.
