Junjie Xie,Kang Li,Zhuonan Shi,Changli Min,Shina Li,Zichen Yin,Ruixin Ma
Cesium and rubidium were effectively separated by zinc ferrocyanide coprecipitation method, and the effect of precipitant addition amount on the separation of cesium and rubidium was studied. Under the conditions of Zn/Cs molar ratio of 0.45 and Zn/Fe molar ratio of 1, the precipitation rate of cesium is 84.01% and the separation factor of Cs/Rb is 164.65. The thermogravimetric curves of the sediment were measured, and the effects of roasting temperature, roasting time, and leaching liquid/solid ratio on the extraction of cesium were studied. Almost all of the cesium was extracted under optimal conditions: roasting temperature of 600 °C, roasting time of 3 h, leaching temperature of 25 °C, leaching time of 0.5 h, and liquid/solid ratio of 5:1 mL/g. After the leaching process, the leach liquor with high concentration of cesium of 80.17 g/L was obtained. Finally, the leach liquor was further purified by solvent extraction, and the purity of the cesium chloride product reached 99.66%. Graphical Abstract
Weathered rare earth ores are an important strategic mineral resource in China, and they are the primary source of medium and heavy rare earths (MHRE). The efficient recovery of MHRE is of great significance from an industrial standpoint. In this study, fulvic acid (FA) is employed as a precipitant to investigate the precipitation of rare earth (RE). The results indicate that the precipitation rates ( w ) of RE range from 89.69 wt% to 99.86 wt% with the pH of 9, the molar ratio of 2, and the temperature of 40 °C, except for Lu 3+ , the w reaches 97.33 wt% with the pH of 9, the molar ratio of 3, and the temperature of 25 °C. The w of RE in the ammonium acetate rare earth leaching solution ranges from 95.99 wt% to 98.54 wt%, with the MH/L of the rare earth distribution after precipitation increasing from 0.77 to 0.80. The use of FA as a precipitant is demonstrated to yield effective precipitation of RE, particularly those of MHRE. FA complexes with RE 3+ , where deprotonation of COO – increases the surface electron density of oxygen atoms, creating additional active sites for electron-deficient RE 3+ . The mechanism provides a theoretical basis for using carboxylic acid compounds as new precipitants. Further, a novel technology for FA complexation precipitation of RE from lignite extract is proposed.
危险品化学品经营许可证（带存储）