Spectroscopic Study of the Behavior of Mo(VI) and W(VI) Polyanions in Sulfuric-Phosphoric Acid Mixtures
文献类型：期刊论文
| 作者 | BSRF用户 |
| 刊名 | INORGANIC CHEMISTRY
 |
| 出版日期 | 2021 |
| 卷号 | 60期号:23页码:17565--17578 |
| ISSN号 | 0020-1669 |
| DOI | 10.1021/acs.inorgchem.1c02133 |
| 文献子类 | Article |
| 英文摘要 | The solution chemistry of Mo(VI) and W(VI) in mixtures of sulfuric and phosphoric acids is relevant to the development of practicable hydrometallurgical processes for the recovery and separation of these two elements from low-grade scheelite ores. The behavior of Mo(VI) and W(VI) in such mixtures has been studied using X-ray absorption near-edge structure (XANES) and extended X-ray absorption fine structure (EXAFS), nuclear magnetic resonance (NMR), and small-angle X-ray scattering (SAXS) spectroscopies, along with electrospray ionization time-of-flight mass spectrometry (ESI-TOF-MS). Where applicable, these techniques have produced a self-consistent picture of the similarities and differences between the chemical speciation of Mo(VI) and W(VI) as functions of solution composition, mostly at a constant phosphorous/metal (P/M; M = Mo(VI) or W(VI)) ratio of similar to 1. In dilute acidic media (0.02 mol.kg(-1) H+, without H2SO4), Mo(VI) exists mostly (similar to 60%) as P2Mo5O236- (10%), with the remaining similar to 40% as beta-Mo8O264-. Under the same conditions, W(VI) is largely present as NaPW11O396- (similar to 80%) and P2W5O236- (similar to 10%), with the remainder probably occurring as isopolytungstates such as W12O4212- and some tungstophosphate dimers such as P2W18O626-. At higher acid concentrations (<= 5 mol.kg(-1) H2SO4), polymeric Mo(VI) anions are broken down to form the oxocations MoO22+ and Mo2O52+ and their protonated forms, with the dimers becoming increasingly dominant at higher acidities (similar to 80% in 5 mol.kg(-1) H2SO4). In stark contrast, W(VI) polyanions do not decompose at higher acidities but instead form (similar to 70% in 0.6 mol.kg(-1) H2SO4) a Keggin ion, PW12O403-. Further acidification with H2SO4 results in the agglomeration of this Keggin ion, forming clusters of about 50 and 100 angstrom in diameter that ultimately produce crystalline precipitates, which could be identified in part by their X-ray diffraction patterns. Possible application of these findings to the hydrometallurgical separation of Mo and W using acidic solutions is briefly discussed, based on a limited number of batch solvent extractions. |
| 电子版国际标准刊号 | 1520-510X |
| WOS研究方向 | Chemistry |
| 语种 | 英语 |
| WOS记录号 | WOS:000753441100017 |
| 源URL | [http://ir.ihep.ac.cn/handle/311005/293310]  |
| 专题 | 北京同步辐射装置 |
| 推荐引用方式 GB/T 7714 | BSRF用户. Spectroscopic Study of the Behavior of Mo(VI) and W(VI) Polyanions in Sulfuric-Phosphoric Acid Mixtures[J]. INORGANIC CHEMISTRY,2021,60(23):17565--17578. |
| APA | BSRF用户.(2021).Spectroscopic Study of the Behavior of Mo(VI) and W(VI) Polyanions in Sulfuric-Phosphoric Acid Mixtures.INORGANIC CHEMISTRY,60(23),17565--17578. |
| MLA | BSRF用户."Spectroscopic Study of the Behavior of Mo(VI) and W(VI) Polyanions in Sulfuric-Phosphoric Acid Mixtures".INORGANIC CHEMISTRY 60.23(2021):17565--17578. |
入库方式： OAI收割
来源：高能物理研究所
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