粗铅用连续结晶器分离银和铋

SEPARATING SILVER AND BISMUTH FROM WORK LEAD BY CONTINUOUS CRYSTALLIZER

根据 Pb—Ag、Pb—Bi 系相图,分析了铅连续结晶过程中银和铋的分离特点,得出银比铋更易结晶分离的结论。铅结晶过程中必须对大量的中间半成品进行强化熔析和反复结晶,并由此确定了结晶器的供热和作业制度。工业规模的试验表明,银的脱除率为99.5%,铅含银可达3克/吨,铋的脱除率为82%。连续结晶器得到的富银铅采用真空蒸馏获得含银>80%的粗银。表明了采用连续结晶器—真空蒸馏方法从粗铅中分离并提取银技术上的可靠和经济上的合理。

On the basis of the phase diagrams of Pb-Ag and Pb-Bi systems,characteristic features of separating silver and bismuth in the process of lead continuous crystalli- zation are analysed,leading a conclusion that silver is easier to separate by crystalliza- tion than bismuth.In the process of lead crysiallizalion it is necessary for a consid- erable quantity of mid-products to undergo enforced liquation and repeated crystalliza- tion,which can provide a guideline to determine the regimes for heat supply and op...