期刊文献+
共找到1篇文章
< 1 >
每页显示 20 50 100
Hydrometallurgical recycling of NdF eB magnets: Complete leaching, iron removal and electrolysis 被引量:7
1
作者 Mehmet Ali Recai Onal Chenna Rao Borra +2 位作者 Muxing Guo Bart Blanpain Tom Van Gerven 《Journal of Rare Earths》 SCIE EI CAS CSCD 2017年第6期574-584,共11页
NdFeB magnets currently dominate the magnet market. Supply risks of certain rare earth metals(REM), e.g. Nd and Dy, impose efficient recycling schemes that are applicable to different types and compositions of these... NdFeB magnets currently dominate the magnet market. Supply risks of certain rare earth metals(REM), e.g. Nd and Dy, impose efficient recycling schemes that are applicable to different types and compositions of these magnets with minimum use of chemicals and waste generation. In this study, a hydrometallurgical method was studied that could be adjusted to recover not only REM, but also other valuable metals(e.g.Co, Ni and Cu) that co-existed in the magnet. The magnet powders were completely dissolved in a dilute sulfuric acid solution giving more than 98% of dissolved iron in the ferrous state. Chemical oxidation of Fe-(2+) into Fe-(3+) by the addition of MnO 2 required only 1 h at ambient temperature. It was then possible to precipitate more than 99% of this ferric iron by adjusting the pH of the solution above 3 with either Ca(OH)2 or MnO additions. However, the addition of Ca(OH)2 resulted in the formation of gypsum and up to ca. 23% REM losses, possibly via co-precipitation into the gypsum. MnO elevated the Mn-(2+) concentration in the solution. However, it was found to be problematic that subsequent direct electrolysis removed Mn and Co. Low anodic current efficiencies(ACE) resulted in high energy consumption(EC), while incomplete Mn and Co removals and undesired REM losses were reported. Pre-electrolysis removals of REM and/or Co by oxalate and/or sulfide precipitation were proven to be successful and selective, but this enlarged the flowsheet considerably with only minor improvement of the Mn removal, ACE and EC. 展开更多
关键词 electrolysis magnet recycling precipitate leaching anodic subsequent ferrous dissolved leachate
原文传递
上一页 1 下一页 到第
使用帮助 返回顶部