KINETIC STUDY ON THE REMOVAL OF LEAD AND SILVER FROM CRUDE BISMUTH BY ANODE REFINING
来源期刊:中南大学学报(英文版)1994年第1期
论文作者:Zhang Yongjian Ren Hongyan Xie Zhong
文章页码:59 - 62
Key words:refine of bismuth; molten salts electrorefining; anode refining
Abstract: The anode refining process to remove lead and silver from crude bismuth was studied. The study was carried out with chloride melts at 400 ℃ in a crucible-in-crucible type pyrex glass electrolyzer. The kinetic regularity of the removal of lead and silver was found to be in accordance with the equation:Inc=b-kt. Values of constant k were determined for different current density.The relationship between the purity of refined bismuth and its direct yield wasalso determined. A two-stage anode refining method was established. The firststage. was to remove most part of lead (about 90%) at higher current density ;the second stage was used for removing silver and the remains of lead at lowercurrent density. Under appropriate conditions high purity (WPb < 0.001%,WAd<0.004%) of bismuth could be obtained from crude bismuth with the direct yield of bismuth up to 98%. Abstract:The anode refining process to remove lead and silver from crude bismuth was studied. The study was carried out with chloride melts at 400 ℃ in a crucible-in-crucible type pyrex glass electrolyzer. The kinetic regularity of the removal of lead and silver was found to be in accordance with the equation:Inc=b-kt. Values of constant k were determined for different current density.The relationship between the purity of refined bismuth and its direct yield wasalso determined. A two-stage anode refining method was established. The firststage. was to remove most part of lead (about 90%) at higher current density ;the second stage was used for removing silver and the remains of lead at lowercurrent density. Under appropriate conditions high purity (WPb < 0.001%,WAd<0.004%) of bismuth could be obtained from crude bismuth with the direct yield of bismuth up to 98%.