摘要
通过TG、XRD、SEM和MS分子模拟的方法,研究了结晶硫酸铝脱水过程中晶型与形貌的变化特点,为结晶硫酸铝制备冶金氧化铝提供了理论基础。依据晶体结构变化特点,将结晶硫酸铝脱水分为3个阶段第一阶段（30~80℃）脱水2.7份,属于三斜晶系;第二阶段（80~22℃）脱水12.65份,属于单斜晶系;第三阶段（322~383℃）脱水1.15份,属于六方晶系。MS模拟结果和SEM形貌观察表明,结晶硫酸铝单晶在脱水过程中,其形貌经历了从片状到粒状再到片状的过程,其中无水硫酸铝的片状暴露面与十七水硫酸铝的片状暴露面呈垂直关系。在结晶硫酸铝到无水硫酸铝的制备过程中,伴随明显体积收缩和颗粒碎裂。采用多晶结晶硫酸铝脱水,具有制备砂状氧化铝的潜力。
The variation features of crystalline shape and morphology of hydrate aluminum sulfate in the dehydration process by TG, XRD, SEM, and molecular simulation were investigated, and the theoretical data for alumina preparation from hydrate aluminum sulfate was offered.The dehydration was divided into three steps according to the transformation of crystal structure. In the 1st step （30-80 ℃） ,2.7 moles of water was dehydrated,and the structure belonged to triclinic system. In the 2nd step （80-322 ℃ ）, 12.65 moles of water was dehydrated,the structure belonged to monoclinic system.The 3rd stage occurred at 322-383 ℃ with 1.15 mole water loss,and the structure belonged to hexagonal system.Results of SEM and MS simulation showed that in the dehydration process, the crystal morphology transformed from flake-like to granular-like, and finally to flake-like again.The exposed surfaces of anhydrous aluminum sulfate were vertical to that of 17-hydrate aluminum sulfate.In the preparation of anhydrate aluminum sulfate from hydrate aluminum sulfate,obvious volume shrinkage occurred with breaking of granules.The dehydration of multi-crystalline hydrate aluminum sulfate is a potential way to prepare sand-like alumina.
出处
《无机盐工业》
CAS
北大核心
2016年第11期17-20,共4页
Inorganic Chemicals Industry
基金
国家863重大项目(2011AA06A102)
关键词
硫酸铝
脱水
形貌模拟
氧化铝
aluminum sulfate
dehydration
morphology simulation
alumina
