用阴极沉淀法制备超细金属氧化物粉体

针对超细氧化物粉体制备条件苛刻、体系复杂等问题,对阴极沉淀制备氧化物方法进行研究。采用自制的以阴离子渗透膜为隔膜的两室电解装置,在阴极电流密度为50~150 A/m2时,对热解Ti3+、Mg2+及两复合离子的阴极沉淀物进行对比分析实验,探讨分散剂、电流密度、溶液pH值等因素对氧化物形貌和粒度的影响。结果表明:三种沉淀均能得到粒度较均匀的超细氧化物,易于水解沉淀得到的TiO2粒度随电流密度增加变化不明显,经过热解氢氧化镁得到的MgO,其粒度随电流密度增加呈增大的趋势,而复合离子氧化物的粒度更接近同条件下得到的MgO粒度。添加分散剂前后制备的氧化物颗粒形貌未见明显变化。该方法具有一定的通用性,通过金属离子沉淀、热解可以得到粒度较均匀的超细氧化物。

Preparation of ultrafine metal oxide by cathode precipitation method

This paper is focused specifically on studying the preparation method of cathode precipita- tion for uhrafine oxides in response to harsher conditions and more complex systems associated with the ultrafine oxide powder preparation. The research involves using self-designed two compartment electrolytic device formed from anion permeable membrane as a diaphragm to perform the contrast experiments of the pyrolysis of cathode precipitation of Ti3＋, Mg2＋ and its two composite ions in range of 50 -150 A/m2 and thereby explore the effect of dispersing agent, current density, pH value of solution and other factors on the morphology and particle size of the oxide. The results show that among the three precipitation proces- ses capable of producing ultrafine oxides of evenly distributed particles are ： Ti3 ＋ hydrolyzing precipitation set to give the particle size of TiO2 which shows no significant change with the increase of current density ; hydrolyzing magnesium hydroxide able to produce the particle size of MgO which tends to increase due to the increasing current density; and oxides of both composite ions capable of providing the particle size closer to the particle size of MgO made under the same conditions. There is no obvious change in mor- phology of oxide particles produced before and after addition of dispersant agent. This method with a bet- ter versatility is able to produce uhrafine oxides with the uniform particles due to the metal ion precipitati- on and pyrolysis.