Abstract Silver is massively present in the pyrometallurgical refining of bismuth, for the aim of effectively removing it, an innovative physical method of centrifugal separation was proposed in this work. And a two-step separation process was conducted according to the theoretical analysis of Bi-Ag and Bi-Ag-Zn phase diagrams. The micro-structure and macro-morphology of the samples obtained from the two-step separation were introduced. And the removal mechanism of silver from bismuth melt was investigated. The filtrated bismuth and bismuth-rich phase concentrated from the preliminary and secondary separation experiments mainly migrated to the lower part of the crucible, whereas the residues of precipitated Ag-Bi phase and Ag-Zn phase were found in the upper part of the crucible. In contrast, there was no separation of phases when it was in the normal-gravity field. After centrifugal separation with the theoretical amount of zinc addition at T = 543 K (270 °C) and G = 400, the purity and yield of bismuth-rich phase were up to 99.38 wt% and 83.92%, respectively. And the removal rate of silver and zinc reached 99.84% and 91.16%. Accordingly, the separation of silver from bismuth melt was found to be practical in a centrifugal separator, which featured the high-efficiency, environmental friendliness and low energy consumption.

中文翻译：

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在离心分离器中以锌为添加剂从铋熔体中分离银

摘要 铋的高温冶金精炼中含有大量银，为有效去除铋，本文提出了一种创新的物理离心分离方法。并根据Bi-Ag和Bi-Ag-Zn相图的理论分析进行了两步分离过程。介绍了两步分离所得样品的微观结构和宏观形貌。研究了铋熔体中银的去除机理。初步和二次分离实验中滤出的铋和富铋相主要迁移到坩埚下部，而沉淀的Ag-Bi相和Ag-Zn相残留在坩埚上部。相比之下，在正常重力场中没有相分离。在 T = 543 K (270 °C) 和 G = 400 下以理论锌添加量离心分离后，富铋相的纯度和产率分别高达 99.38 wt% 和 83.92%。并且银、锌的去除率分别达到99.84%和91.16%。因此，发现从铋熔体中分离银在离心分离机中是可行的，具有高效、环保和低能耗的特点。