KF-AlF_(3)熔盐低温可视化电解NEU-1月壤仿真样

Visualization electrolysis of NEU-1 lunar soil simulant in KF-AlF_(3)electrolyte at low-temperature

以57Fe-43Ni合金为惰性阳极、以镍网为阴极并用于盛装月壤仿真样,在650℃的43KF-57AlF_(3)电解质体系中电解NEU-1月壤仿真样。利用透明槽可视化观察了电解过程中电极反应现象,并通过X-射线衍射(XRD)、能谱分析(EDS)和红外在线检测仪分别对电解质、阴极产物和阳极气体进行了表征。研究发现,在电解过程中电解质呈现三种不同颜色层,上层电解质为黄棕色,其冷凝后物相是KAlF_(4)和Fe_(3)O_(4);中层侧部为透明电解质,中心区域呈黑色,冷凝后物相为SiO_(2),NiO和Fe-Ni,在中层侧部还发现有少量Fe_(3)O_(4)和Al-Fe合金;下层呈蓝紫色,主要物相为Al,Al_(2)O_(3)和Fe-Ni-Si-Ti合金;阴极附近有小颗粒金属产物,阴极镍网外表面样品的主要成分为Fe(35.09wt%),还含有少量的Ti(1.06wt%),Al(9.38wt%)和Si(3.62wt%);电解过程中阳极底掌持续生成氧气,电解2 h后产生的气体中氧气的体积分数稳定在95vol%。

Electrolysis of NEU-1 lunar regolith simulants was operated in 43KF-57AlF_(3)electrolyte at 650℃in a quartz crucible.The Fe-Ni alloy was used as inert anode which consisted of 57Fe-43Ni and the cathode was made of nickel mesh with the lunar soil simulant in it.Electrode reaction phenomena during electrolysis were visualized using a see-through cell and electrolytes,cathode products and anode gas were characterized by X-ray Diffraction(XRD),Energy Display Spectrometer(EDS)and gas infrared on-line analyzer.The see-through cell was designed with a transparent quartz window in order to observe the phenomena during the electrolysis,It was found that different zones of the electrolyte showed different colors during the electrolysis.The electrolyte divided into three zones as the upper zone,the mid layer and the lower layer.Specifizally,in the upper zone,electrolyte appeared yellowish-brown,and its main phase were KAlF_(4)and Fe_(3)O_(4)after condensation.The electrolyte in the mid-layer was transparent,while the center area was black,and the phases after condensation were SiO_(2),NiO,and Fe-Ni,along with small amount of Fe_(3)O_(4)and Al-Fe alloy found in the side of mid-layer.The lower layer was bluish-purple metal fog with the predominant phases being Al,Al_(2)O_(3),and Fe-Ni-Si-Ti alloy.The metal products were present in the form of fine particles located in the area close to the nickel mesh cathode.In the cathode nickel mesh,the main metal product was Fe(35.09wt%),with a small amount of Ti(1.06wt%),Al(9.38wt%),and Si(3.62wt%).It was found that gas bubbles were continuously generated at the bottom of the inert anode during the electrolysis in the see-through cell.Furthermore,an experiment was designed to collect the gas which generated by the electrolysis and detect the anode gas by using an on-line infrared gas analyzer.The result indicated that after 2 hours of electrolysis,the volume fraction of oxygen in the anode gas was stabilized at 95vol%.