前驱体预处理及卤化铵添加剂对α-氧化铝微粉颗粒形貌的影响  

Effect of pretreated precursor and halogenated ammonia additives on the morphology of α-Al_2O_3 powders

作　　者：孙春晖[1] 朱玲玲[1] 李赛 刘洛强 陈留刚[1] 叶国田[1] Sun Chunhui;Zhu Lingling;Li Sai;Liu Luoqiang;Chen Liugang;Ye Guotian(School of Materials Science and Engineering,Zhengzhou University,Zhengzhou 450001,China)

机构地区：[1]郑州大学材料科学与工程学院,河南郑州450001

出　　处：《无机盐工业》2018年第9期19-23,共5页Inorganic Chemicals Industry

基　　金：2015年度NSFC-河南人才培养联合基金项目(U1504526);2014年度郑州大学优秀青年教师发展基金项目(1421320048)

摘　　要：以工业氢氧化铝为前驱体,通过X射线衍射(XRD)和扫描电镜(SEM)分析方法,研究了前驱体经轻烧再经球磨预处理的物相转变及形貌演变,并进一步研究了在预处理后的前驱体中添加氟化铵、氯化铵以及氟化铵和氯化铵的复合物后,经过高温煅烧所得α-氧化铝的颗粒形貌演变规律。实验结果表明:前驱体经650℃轻烧再经3 h球磨,所得样品主要物相为γ-氧化铝,样品由颗粒尺寸小于10μm的不规则片状颗粒组成,其中包含大量尺寸小于1μm的不规则颗粒;预处理后的前驱体经1 400℃煅烧2 h,所得样品为α-氧化铝,蠕虫状空间网络结构得到部分抑制;在预处理后的前驱体中加入1%氟化铵(质量分数)时,在相同条件下煅烧所得样品为粒度分布在1μm左右的片状α-氧化铝,但片状结构尚不规则,粒度分布也不均匀;在预处理后的前驱体中加入1%氯化铵(质量分数)时,对α-氧化铝的颗粒形貌影响不大,所得样品形貌与无添加剂时类似,但初始晶粒尺寸略显细化;与单一加入1%氟化铵(质量分数)相比,在预处理后的前驱体中加入0.5%氟化铵(质量分数)和0.5%氯化铵(质量分数)复合添加剂时,促使片状α-氧化铝转变为圆饼状α-氧化铝,且粒度分布更为均匀,绝大部分圆饼状颗粒尺寸分布在1μm左右。With the introduction of calcination at low temperature and milling treatment,the phase composition and morpho-logy evolution of pretreated precursor were analyzed by X-ray diffraction(XRD)and scanning electron microscopy(SEM),using commercial Al(OH)3 as raw material.And then the morphology evolution ofα-Al2O3 synthesized from pretreated precursor was studied by using NH4F,NH4Cl or NH4F-NH4Cl compound as additives.Results showed thatγ-Al2O3 emerged after the calcination of Al(OH)3 at 650℃for milling of 3 h,and theγ-Al2O3 sample consisted of irregular plate-like particles in the size of≤10μm,a large amount of crushed pieces in a≤1μm size range were coexisted on the grain surface or interspace among precursor grains.The typically worm-like network structure has been partially suppressed in theα-Al2O3 sample from the pretreated precursor by calcination at 1 400℃for 2 h.Plate-like structure with a size about 1μm was prepared from the pretreated precursors with 1%(mass fraction)NH4F additive under the same calcination condition,though the plate-like morphology and particle were ununiformed.While the morphology ofα-Al2O3 obtained from the pretreated precursors with 1%(mass fraction)NH4Cl additive was similar to theα-Al2O3 sample prepared from the pretreated precursors without additive,though the primary grain size was slightly refined under the influence of NH4Cl additive.Comparison with single additive,the morphology and particle size distribution ofα-Al2O3 powders have been significantly improved by 0.5%(mass fraction)NH4F and 0.5%(mass fraction)NH4Cl composite additives,resulting in the formation of round cake likeα-Al2O3 with a size about 1μm.

关 键 词：Α-氧化铝 前驱体预处理 颗粒形貌 卤化物添加剂 气相传质 

分 类 号：TQ133.1[化学工程—无机化工]