Method used for separating rare earth from bastnaesite sulphuric acid leach solution and preparing ice stone

Abstract

The invention belongs to the technical field of rare earth hydrometallurgy, and specifically relates to a method used for separating rare earth from a bastnaesite sulphuric acid leach solution and preparing an ice stone. The method comprises the following steps of: adding aluminium salt as a fluorine complexing agent in a bastnaesite sulphuric acid leach solution, mixing an extraction agent and a diluting agent to obtain an organic phase, mixing the organic phase and the bastnaesite sulphuric acid leach solution according to the volume ratio of (1-10):1, vibrating for 5-60 minutes, and splitting phase after standing for 10-60 minutes; and obtaining the organic phase of loading cerium and an extractive surplus phase containing fluorine and trivalence rare earth, adding a sodium compound in the extractive surplus phase, adjusting pH to 2-5, obtaining Na3AlF6 precipitation, namely the ice stone, carrying out solid-liquid separation, and obtaining the trivalence rare earth solution after defluorination. Compared with the prior art, the method provided by the invention reduces the generation of three wastes containing fluorine due to fluorine recovery, greatly lightens the environmental pollution from a flow, can carry out reclamation utilization on fluorine in a water phase, and reduces the waste of a fluorine resource.

Description

technical field [0001] The invention belongs to the technical field of rare earth hydrometallurgy, and in particular relates to a method for separating rare earth from bastnaesite sulfuric acid leaching solution and preparing cryolite. Background technique [0002] Bastnaesite is the world's largest reserve, and is currently the largest amount of rare earth mineral resources mined and used. Its composition is mainly light rare earth elements, and it is also associated with valuable resources of 0.1~0.2wt.% thorium and 7~9wt.% of fluorine. [0003] At present, there are more than 10 kinds of techniques used in the decomposition of bastnaesite and the extraction of rare earths. In summary, there are mainly acid methods and alkali methods. Among them, the acid methods mainly use hydrochloric acid or sulfuric acid, such as concentrated sulfuric acid roasting method. , so that HF ​​gas and sulfuric acid mist are easy to be generated in the process, which not only pollutes the e...

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Problems solved by technology

[0005]The above methods all achieve Ce4+, RE3+, F- The separation of , due to the strong coordination ability of fluorine, increases the difficulty of subsequent separation and treatment of rare earths. A lot of research work is needed to realize industrial application, and fluorine is treated as a useless element, and fluorine is not really treated. Resource utilization as a resource also causes a great waste of fluorine resources. If the fluorine / rare earth can be separated by adding a fluorine complexing agent before or during the extraction process, the impact of fluorine on the subsequent treatment process can be eliminated. Then leaching and separation of rare earths can be carried out, and the resource utilization of fluorine can be carried out, so as to finally realize the clean production of rare earth smelting and the comprehensive utilization of resources

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