Study On Green Separation Process Of Light And Heavy Rare Earth By Cyanex923

This thesis based on the green separation process of rare earths,focusing on the separation and recovery process of light rare earth?Ce?and heavy rare earth?Sc?.The Cyanex923 was regarded as the main extractant which dedicated to study the extraction and interaction of various elements in Ce?IV?-P?Ce?IV?-F-P complex systems.At the same time,the mixed nanoparticles of CeF₃ and CePO₄ were prepared by liquid phase separation.A synergistic extraction study of Sc in a sulfuric acid medium was carried out using the mixed system of Cyanex272+Cyanex923.The separation performance of the mixed system for each element of the laterite nickel ore leachate was further tested.Detailed research work were arranged as follows:1.Taking the clean metallurgical separation of Baotou ore as the main line,the comprehensive recovery process of Ce?IV?,F and P in Baotou light rare earth ore has been investigated in this paper.The oxidation-roasting and sulfuric acid leaching process of Baotou rare earth were carried out to obtain the best roasted conditions and leached parameters.The process of extracting and separating Ce?IV?from sulfuric acid leachate containing Ce?IV?,F and P and its influencing factors were analyzed in detail using Cyanex923.Taking advantage of the interaction between Ce?IV?and F/P in the solution,the powders were prepared by reductive stripping with H₂O₂,and F/P were also recovered in the form of CeF₃ and CePO₄.2.For the purpose of separation and recovery of trace scandium element in scandium-containing waste slag,the synergistic extraction study of Sc in a sulfuric acid medium was carried out using the system of Cyanex272+Cyanex923.The effects of acidity,extractant concentration,extractant ratio and temperature on the extraction have been investigated.The synergistic mechanism of the system was elaborated,and the synergistic reaction equation and the composition of the saturated extracted complex were derived.Simultaneously,the actual extraction and separation experiment of the scandium-containing liquid was carried out.The separation experiment of the laterite nickel ore leachate showed that the system could achieve the selective separation of Sc?III?from other elements.