含氧酸根检测方法的研究现状及质谱法在钨钼分离中的应用前景

Research status of oxygen-containing acid root detection methods and application prospect of mass spectrometry in tungsten-molybdenum separation

溶剂萃取法具有操作简单、回收率高、产品纯度高等优点,被广泛应用于钨钼分离。分离过程中钨钼离子形态会影响与萃取剂的结合方式及萃取历程,因而研究钨钼的离子形态变化有助于深入了解钨钼分离机理,进而指导工业生产。在水溶液中,钨钼的离子形态以钨钼含氧酸根形式存在,研究钨钼离子形态的本质即研究不同钨钼含氧酸根形式对萃取分离过程的影响。本工作综述了水溶液中含氧酸根离子形态的仪器分析方法,发现ESI-MS(电喷雾质谱法)在监测萃取过程中钨钼离子形态转化路径中具有潜在应用,并对ESI-MS在湿法冶金领域中监测钨钼离子形态及其转化规律的应用进行了展望,旨在为今后深入了解钨钼分离机理、定向调控钨钼分离过程及工业生产提供理论指导。要点:(1)综述了仪器分析方法在监测水溶液中含氧酸根离子形态的应用与优缺点。(2)阐明了离子形态在钨钼分离等湿法冶金过程中的重要性。(3)展望了ESI-MS在湿法冶金领域监测钨钼离子形态的应用。

Tungsten and molybdenum are rare high melting point metals and play important roles in national economy and defense. Tungsten and molybdenum often co-exist in natural resources. Due to the effect of "Lanthanide Contraction", their atomic radius and chemical properties are very similar, so that it is difficult to separate them. Therefore, the separation of tungsten and molybdenum has always been the focus of researches. Solvent extraction method has the advantages of simple operation, high recovery rate and high purity, which is widely used in the separation of tungsten and molybdenum. When separating tungsten and molybdenum by extraction, tungsten and molybdenum speciation will affect the combination mode with extractant and extraction process. The study of tungsten and molybdenum speciation in the recovery process is helpful to deeply understand the separation mechanism of tungsten and molybdenum, so as to provide guidance for industrial production. In aqueous solution, tungsten and molybdenum speciation exists in the form of tungsten/molybdenum oxygen-containing acid radical. The essence of studying tungsten and molybdenum speciation is to investigate the influence of different forms of tungsten–molybdenum oxygen-containing acid radical on the extraction and separation process. In previous studies, people focused on the study of metal speciation in biological and environmental fields, however, little literature reported the role of ions speciation in the separation and recovery of tungsten and molybdenum. Although p H-potentiometric titration and thermodynamic calculation methods have been used to study the ions speciation in aqueous solution, they are always inaccurate and have limitations in predicting the distribution and transformation process of metal ions or complexes. Therefore, instrumental analysis methods are needed to determine species speciation and transformation process. In this work, instrumental analysis methods of oxygen-containing acid radical ions speciation in aqueous solution were summarized. ESI-MS had potential applications in monitoring tungsten/molybdenum transformation pathways in the extraction process. In addition, monitoring methods of tungsten and molybdenum speciation and their transformation pathways in hydrometallurgical fields were prospected. Finally, theoretical guidance for further understanding of tungsten–molybdenum separation mechanism and directional regulation as well as industrial production was provided. Key learning points:(1) Application as well as advantages and disadvantages of instrumental analysis methods in monitoring the speciation of oxygen-containing acid radical ions in aqueous solution were reviewed.(2) The importance of speciation in hydrometallurgical processes such as tungsten–molybdenum separation was stated.(3) ESI-MS in monitoring tungsten and molybdenum speciation in the field of hydrometallurgy was prospected.