A Study on the Removal of Impurity Elements Silicon and Zinc from Rubidium Chloride by Vacuum Distillation

Abstract

With the rapid development of high and new technology, rubidium and its compounds show broad application prospect and market demand with their unique characteristics. At present, the production of rubidium metal is mainly prepared by calcium thermal reduction of rubidium chloride. Rubidium metal obtained by reduction requires multi-step vacuum distillation to obtain high-purity rubidium metal. The purity of rubidium metal depends on the purity of the raw material rubidium chloride. Rubidium metal is relatively active and is easy to oxidize and explode in air. Therefore, a method combining vacuum decomposition and vacuum distillation to reduce impurity elements in rubidium chloride from raw materials is proposed in this paper. The experimental results show that under the conditions of pressure of 5–10 Pa, distillation temperature of 823 K and vacuum distillation time of 60 min, the contents of Si and Zn impurities are reduced from 1206 mg/kg and 310 mg/kg to less than 0.1 mg/kg, and the removal rates are 99.99% and 99.97%, respectively. Rubidium chloride has almost no loss, and through one-step vacuum distillation, the impurity elements silicon and zinc can be deeply removed, reducing the flammability and explosiveness, high cost, long process and other problems caused by the subsequent preparation of high-purity rubidium metal.