熔融富铌渣电解提铌的试验研究

Experimental Investigation on the Electrochemical Extraction of Niobium from Molten Nb-enriched Slag

为实现富铌渣中铌资源电化学选择性还原和分离,采取熔融氧化物电解技术,对含铌SiO_2-CaO-FeO-Nb_2O_5渣体系进行电解试验,以研究电解电势、熔渣组成等因素对富铌渣电化学还原率的影响。结果表明:熔融氧化物电解可实现含铌熔渣中铌资源的提取;铌还原率随着电解电势的增大而提高,随着熔渣中Nb_2O_5和FeO含量增加而降低。通过对熔渣电解过程的分析并结合电化学还原原理,建立了富铌渣电化学还原过程中的控制方程,揭示了降低气氛氧分压、提高电解电势、选择合适的熔渣体系等途径提高电化学还原效率的规律,为富铌渣中铌资源的电化学提取分离提供理论依据。

The known technology of molten oxide electrolysis is applied to electrochemical selective reduction and separation of the niobium from the complex multiphase Nb-enriched slag,and the molten oxide electrolysis experiment of the selected SiO 2-CaO-FeO-Nb 2O 5 slag system has been carried out to investigate the effects of electrolysis potential and slag composition on the electrochemical reduction rate of Nb-enriched slag.The results indicated that the extraction of niobium from Nb-enriched slag can be achieved by molten oxide electrolysis.The reduction rate of niobium increased with the increase of electrolysis potential,and decreased with the increase of Nb 2O 5 content and FeO content in slag.Through the analysis of slag electrolysis process and on the basis of principle of electrochemical reduction,the control equations for the process of electrochemical reduction of Nb-enriched slag were established.The law of reducing the oxygen partial pressure,increasing the electrolysis potential,selecting the appropriate slag system and so on to improve electrochemical reduction efficiency was revealed,which provided a theoretical basis for the electrochemical extraction and separation of Nb from molten Nb-enriched slag.