TiO_2-Fe_2O_3氧化物阴极的制备工艺研究  

Preparation of TiO_2-Fe_2O_3 Cathode for FFC Process

作　　者：王碧侠[1] 孔维明[1] 凌阿朋[1] 包洋[1] 张军[1] 折建伟[1] 

机构地区：[1]西安建筑科技大学冶金工程学院,陕西西安710055

出　　处：《稀有金属》2013年第3期378-383,共6页Chinese Journal of Rare Metals

基　　金：国家自然科学基金重点项目(50434030)资助

摘　　要：FFC(熔盐电脱氧)工艺是一种用电化学还原法从混合金属氧化物制备Ti-Fe合金的新工艺,具有短流程、低能耗的特点。选择合适的阴极制备工艺对后续的电化学还原至关重要。采用模压成型和烧结的工艺制备TiO2-Fe2O3混合氧化物阴极,研究了阴极片的成型压力、造孔剂种类及用量、烧结温度等阴极成形和烧结过程中的主要因素对阴极孔隙率和微观结构的影响。用SEM及EDS对阴极片的微观结构和元素分布进行分析。结果表明,用碳酸氢氨作造孔剂时,阴极片的孔隙率受温度的影响较大;随着温度的升高和造孔剂含量的增多,烧结的阴极片颗粒直径不断增大,并且在孔隙周边的颗粒直径相对于其他部位要更大些;随着温度的等幅度增加,颗粒直径在造孔剂含量高时随温度升高而增长的幅度较大。对烧结片局部氧元素含量分布不均的现象进行了分析,其原因是高温下物质的内能较高,当能量达到反应活化能时会发生氧化物的分解反应,分解出的氧气通过孔隙向周围扩散,使得局部的氧含量较高。The FFC （molten salt electrodeoxidation） process was a novel technology for the preparation of Ti-Fe alloy from the mixed metal oxides by the electrochemical reduction method, which had the advantage of short flow and low energy consumption. Choosingproper forming and sintering parameters to prepare the oxides cathode was of vital importance to the subsequent electrolytic reduction process. In this paper, the press molding and sintering methods were applied to prepare the cathode from the mixed metal oxides, thenthe main parameters that had influences on the porosity and microstructure of the sintered cathode were investigated, which included the molding pressure, the consumption of the pore-forming agent and the sintering temperature. SEM and EDS were applied for observingthe microstructure and making elements analysis of the sintered pellet. The results showed that the temperature had more influence on the porosity of the sintered pellet when ammonium bicarbonate was used as the pore forming agent; the particle size of the pellet in-creased with the increase of sintering temperature and the consumption of the pore-forming agent, and the particle size around the pore was bigger than those within other areas; with the increase of sintering temperature, the particle size of the pellet had more incrementwhen the amount of the pore-forming agent was higher. The phenomenon for the uneven distribution of the oxygen element within local area of the pellet was analyzed and it implied that the materials had higher internal energy at higher temperature, when it reached to theactive energy of the reaction, the oxides would decompose and the oxygen would release. The produced oxygen would diffuse from the pore to the surrounding area, causing the higher oxygen concentration within local area.

关 键 词：FFC工艺 阴极 制备 孔隙率 微观结构 

分 类 号：TF62[冶金工程—钢铁冶金]