REFINING ANCIENT LEAD BY VACUUM DISTILLATION

A complex method for refining lead by distillation in vacuum has been described. A brief comparative description of different methods of lead refining was submitted. Analysis of different methods showed that to increase the efficiency of lead deep cleaning the development of complex refining processes is required. The computational studies of the behavior of impurity elements in the ancient lead are performed. The ideal coefficients of impurities separation αi are calculated at lead distillation temperatures. The range of volatile and nonvolatile impurities was detected by magnitude αi in lead. Performed computational studies of the impurity elements behavior in lead formed the basis for developing an integrated method of deep refining of ancient lead. To implement this approach the special distillation device was developed, and the procedure of deep purification of lead was described.The results of the study of the deep refining ancient lead have been demonstrated. The cleaning high efficiency of the proposed approach, combined with high performance and yield of the suitable product, was shown. A pilot batch of ancient lead containing base metal > 99.998 wt. % suitable for growing high quality scintillation crystals PbWO4 and PbMoO4 has been produced.