一种低晶种比率生产超细氢氧化铝的工艺方法研究  

Research on preparation process of super-fine aluminum hydroxide with low crystal seed ratio

作　　者：邓魁 裴广斌 王茜 Deng Kui;Pei Guangbin;Wang Qian(Luoyang Zhongchao New Materials Co.,Ltd.,Luoyang 471800,China)

机构地区：[1]洛阳中超新材料股份有限公司,河南洛阳471800

出　　处：《无机盐工业》2020年第10期121-124,共4页Inorganic Chemicals Industry

摘　　要：在较高Nk(铝酸钠溶液中氧化钠质量浓度,g/L)的偏铝酸钠溶液中种分得到用于晶种制备的氢氧化铝,过滤、洗涤后,在水中湿磨滤饼得到D50粒度为1.0μm左右的氢氧化铝浆液,将此浆液按最终晶种比率(晶种中氧化铝含量与溶液中氧化铝含量的比值)小于0.3%的比率,在35~42℃的铝酸钠溶液中分散50~70 min后,加至较低Nk、58~70℃的过饱和铝酸钠溶液中种分35 h左右,过滤,将滤饼洗涤、干燥、分散后得到D50粒度为2.0μm左右的氢氧化铝粉体,使用XRD、SEM对粉体进行了表征,表明粉体为三水铝石(Gibbsite),主要晶型为伪六角块状或四角块状。还对影响产品粒度的重要条件进行了讨论。该工艺有效地解决了超细氢氧化铝生产流程中循环母液杂质累积的问题,同时具有更低的生产成本。The aluminium hydroxide was firstly produced by the seeded precipitation process from the sodium aluminate solution with a higher Nk value(mass concentration of sodium oxide in sodium aluminate solution,g/L)for the crystal seed.After filtration and washing,the aluminium hydroxide serosity with the medium grain diameters D50 of about 1.0μm was grinded and obtained by wet ball-milling in water.The serosity subsequently was added and dispersed into a sodium aluminate solution at a temperature of 35~42℃for 50~70 min,at a final crystal seed ratio of below 0.3%(the ratio of alumina contents between crystal seed and solution).Then the new serosity was added into a sodium aluminate solution with a lower Nkvalue and a temperature of 58~70℃,after a retention time of about 35 h the sodium aluminate solution was filtered,the filter cake was washed and dried.The aluminium hydroxide powder with a particle size of about 2.0μm was obtained.Characterization of XRD and SEM indicated that the product was gibbsite with pseudo-hexagonal or tetragonal block shape.And several important conditions of influencing the particle size were also discussed.The process solved effectively the accumulatiton problem of impurities in the aluminium hydroxide production process and had the lower production cost.

关 键 词：超细氢氧化铝 铝酸钠溶液 种分 晶种比率 晶种 

分 类 号：TQ133.1[化学工程—无机化工]