以99.99％ 高纯铝板为阳极原料,采用电化学方法制备氧化铝前体氢氧化铝,讨论分析了氢氧化铝的焙烧温度、保温时间对制备高纯超细氧化铝的影响,考察了不同电流密度放电对氧化铝形貌和粒度的影响.结果表明:在70 mA·cm?2的较高电流密度下铝/空气电池放电过程可得到平均粒度为268 nm的氢氧化铝;制备的氢氧化铝经洗涤,在1400℃焙烧,保温3 h,可得到平均粒度为200 nm,形貌为近似球状的99.99％的超细氧化铝粉体;而低电流密度所得氧化铝颗粒团聚严重.主要原因是高电流密度使放电过程中产生的氢氧化铝晶体的介稳区宽度变窄所致.%99.99％ high-purity aluminum is introduced as anode material to obtain aluminum hydroxide, the precursor of alumina, by an electrochemical method. The influence of calcination temperature and holding time on preparing high purity and superfine alumina is discussed. And effects on morphology and size of alumina at different current densities are studied. Experimental results show that the average size of 268 nm aluminum hydroxide can be obtained at 70 mA·cm?2, a relative high current density in aluminum/air batteries. After washing aluminum hydroxide and roasting at 1400℃, holding3 h, the average size of 200 nm and near-spherical alumina powder is received. However, alumina particles agglomerate seriously at low current densities, which is mainly caused by narrowing of metastable zone width at high current densities.
展开▼
