Method for separating rare earth oxides from rare earth ore by using ammonium chloride-potassium chloride gas phase transmission

Abstract

The invention provides a method for separating rare earth oxides from rare earth ore by using ammonium chloride-potassium chloride gas phase transmission. The main technical characteristic of the method is as follows: mixing rare earth ore and sodium carbonate to roast; dissolving the decomposition product obtained by roasting in water, drying and grinding insoluble substance to mix with ammoniumchloride and perform chlorination reaction; dissolving the chlorinate to obtain filtrate, adding BaCl2 and H2SO4 in the filtrate to separate precipitates such as ThO2, Fe2O3, U2O3 and the like; treating the filtrate through evaporating, oxidizing and calcining, chlorhydric acid leaching and drying in turn, then adding NH4Cl and KCl to perform chemical gas phase transmission for 20-25 times; dissolving the obtained product with water, adding oxalic acid to obtain lanthanum oxalate, praseodymium oxalate, neodymium oxalate and other rare earth oxalates except for cerium oxalate; then igniting theoxalates above 800 DEG C to obtain corresponding rare earth oxides. The method has the advantages that the problem of separating radioactive elements can be effectively solved, the use of chlorine gas and the emission of wastewater and effluent gas can be reduced in the production process, and the discharged gas can be recyled for reproduction.

Description

Technical field: [0001] The invention relates to a rare earth separation process in metal smelting, in particular to a method for separating rare earth oxides from rare earth ores by utilizing ammonium chloride-potassium chloride gas phase transmission. Background technique: [0002] The separation and purification methods of rare earth elements mainly include chemical separation, ion exchange, and solvent extraction, in addition to extraction chromatography, and liquid membrane separation. The above methods have their own advantages and disadvantages. The fire method developed in recent years is the chemical vapor transport method, and the research results of the separation of rare earths are the continuation of the high-temperature carbothermal chlorination method. Since 1991, Adachi et al. have continuously reported the use of chemical vapor transport (CVT) to separate rare earth elements by forming gaseous complexes, and believe that this method is promising and may repl...

AI Technical Summary

Problems solved by technology

However, the reaction time of this method is as long as tens of hours, and there is still contamination of radioactive elements in the product.

Professor Wang Zhichang proposed the split-step chlorination chemical vapor transport method (SC-CVT) to separate rare earth elements; using the split-step selective chlorination-chemical vapor transport reaction (SC-CVT) method to separate rare earth elements, the low-temperature selection of mixed rare earth oxides Combination of neutral chlorination and high-temperature chemical vapor transmission of mixed rare earth chlorides; the carbon-added chlorination process created solves the problem of ineffective separation of alkaline earth metals and radioactive elements in minerals, but uses toxic and harmful chlorine gas as the chlorination agent; 0.001 mg of chlorine gas can be allowed in 1L of air at most. Exceeding this amount will cause human poisoning or even sudden death; In the process of storage, transportation and production, there are high requirements for equipment and production management

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