氧化铝制备过程中硫酸根的脱除  

Sulfate removal in preparation process of alumina

作　　者：王晓慧[1] 宋云华[1] Wang Xiaohui;Song Yunhua(College of Chemical Engineering,Beijing University of Chemical Technology,Beijing 100029,China)

机构地区：[1]北京化工大学化学工程学院,北京100029

出　　处：《无机盐工业》2018年第8期34-37,共4页Inorganic Chemicals Industry

摘　　要：研究了以工业级硫酸铝铵为原料制备氧化铝的过程中杂质SO_4^(2-)的脱除工艺,并考察了滴加顺序、硫酸铝铵初始浓度、反应温度、滴加速率、终点pH、水热介质和水热温度对SO_4^(2-)脱除的影响。结果表明:在硫酸铝铵初始浓度为0.5 mol/L、反应温度为55℃、滴加速率为4 mL/min、终点pH=9.0、反滴加、水热介质为1 mol/L的精制氨水、水热处理温度为205℃的条件下,可以制得SO_4^(2-)质量分数最低为0.001 5%的Al2O3。水热介质选用氨水可有效增大前驱体粒径,进而大大降低SO_4^(2-)的表面吸附,利于氧化铝中SO_4^(2-)含量的脱除。与传统直接煅烧硫酸铝铵法相比,该工艺煅烧前即洗掉了大量的SO_4^(2-)杂质,有效避免了煅烧不充分造成氧化铝中SO_4^(2-)含量较大的弊端。Impurity SO4^2-removal was investigated in the process of alumina preparation.It was used the industrial-grade ammonium aluminum sulfate as raw material.The influences of the factors,including the dripping sequence,the initial concentration of ammonium aluminum sulfate,the reaction temperature,the dripping speed rate,the pH at end-point,hydrothermal medium and hydrothermal temperature,on the SO4^2-removal effect were discussed.The results showed that： when the initial concentration of ammonium aluminum sulfate was 0.5 mol/L,the reaction temperature was 55 ℃,the dripping speed rate was4 mL/min,the pH=9.0,hydrothermal medium was 1 mol/L of ammonia,and hydrothermal temperature was 205 ℃,alumina with the lowest SO4^2-mass fraction of 0.001 5% could be obtained.It could effectively increase the precursor particle size when the hydrothermal medium was ammonia.Thus it greatly reduced the surface adsorption of SO4^2-,which benefited for the removal of SO4^2-content in alumina.Compared with the traditional method direct calcination ammonium aluminum sulfate,this process washed away a lot of SO4^2-impurities before calcination,which effectively avoided the inadequate calcination causing SO4^2-content larger.

关 键 词：硫酸铝铵 氧化铝 水热反应 SO42- 

分 类 号：TQ133.1[化学工程—无机化工]