Cesium extraction using the solvent extraction method in a centrifugal extractor

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Cesium extraction using a centrifugal extractor solvent extraction method: The method for extracting cesium from cesium-containing materials to produce pure cesium chloride involves a competitive process between the dissolution of the cesium to be extracted in the aqueous phase and its dissolution in the organic phase. Essentially, it is a process of mass transfer, in which the immiscible aqueous phase and organic phase are brought into contact, allowing the cesium to be transferred from the aqueous phase to the organic phase, and then back-extracted into the aqueous solution. The entire process is carried out in the selected CWL-type centrifugal extractor. The solvent extraction method using centrifugal extractors for the separation of cesium and rubidium was developed in the 1960s. It is capable of separating mixtures containing various alkali metal elements together, and in many cases it is faster than the stepwise precipitation method or ion exchange methods. It offers advantages such as simple equipment, short processing procedures, ease of automatic control, high production capacity, safe operation, and low costs, making it a good method for the separation and extraction of cesium and rubidium. The main process of cesium extraction using the solvent extraction method in a centrifugal extractor consists of three basic steps: extraction, washing, and back-extraction. Extraction: The organic phase and the aqueous phase (the aqueous solution) are brought into contact in a certain ratio for a certain period of time, after which extraction equilibrium is achieved. The extracted cesium is transferred from the aqueous phase to the organic phase, after which the two phases are separated clearly. Washing: After extracting cesium from the aqueous phase, the cesium-loaded organic phase is used to mechanically entrain or partially extract impurities such as rubidium and potassium. If direct back-extraction is used, the final product will contain these impurities. Therefore, the cesium-loaded organic phase needs to be washed before back-extraction. Back-extraction: Back-extracting cesium from the washed cesium-loaded organic solvent is achieved by bringing it into contact with an aqueous solution. BAMBP and t-BAMBP are weakly acidic extractants that can only be used for extraction in alkaline solutions.