铝酸钠溶液晶种分解硅析出行为探究  

Investigation on the behavior of silicon deposition from seed decomposition of sodium aluminate solution

作　　者：赵天相 赵恒 杨群太 蓝剑锋 闫程翔 Zhao Tianxiang;Zhao Heng;Yang Quntai;Lan Jianfeng;Yan Chengxiang(Guangxi Huasheng New Material Co.,Ltd.,Fangchenggang 538002,China)

机构地区：[1]广西华昇新材料有限公司,广西防城港538002

出　　处：《轻金属》2024年第11期11-16,34,共7页Light Metals

摘　　要：本文研究了二氧化硅在铝酸钠溶液晶种分解过程中的析出行为。结果表明:SiO_(2)在铝酸钠溶液晶种分解中的析出行为受铝酸钠溶液浓度、分解温度、附聚效率、粒度、有机物杂质行为等的影响。浓度越低要求精液A/S越高,精液Al_(2)O_(3)浓度为143~153 g/L时精液A/S必须大于170才不会导致SiO_(2)大量析出。温度越高硅析出越明显。附聚效率、粒度和硅的析出相互影响,附聚效率好、粒度越粗硅析出量越少,反之硅析出量越大;同时硅的析出也会使氢氧化铝细化和附聚效率的降低,其影响附聚效率程度和硅析出量、氢氧化铝粒径有关。随着硅析出量增加,相同粒径的附聚效果逐渐变差;随粒径变小硅析出对附聚效率的影响越显著,对大于8.98μm以上的附聚效率几乎无影响。有机物和草酸钠杂质的存在直接或间接会影响硅的析出,一方面有机物及草酸钠会使析出的脱硅产物粒度变细,进而诱导二氧化硅的析出;另一方面有机物和草酸钠会使氢氧化铝粒度变细,加剧二氧化硅在氢氧化铝表面的吸附作用。此外,草酸钠大量的析出,在相同分解条件下会加剧铝酸钠溶液中二氧化硅的析出。This paper studied the precipitation behavior of silicon dioxide in the crystal decomposition of sodium aluminate solution.The results show that the precipitation behavior of SiO_(2) in the crystal decomposition of sodium aluminate solution is influenced by the concentration of sodium aluminate solution,precipitation temperature,agglomeration efficiency,particle size and impurity behavior of organic matter.The lower the concentration requires the higher the A/S of sodium aluminate solution,when the concentration of sodium aluminate solution Al_(2)O_(3) is 143~153 g/L,the A/S of sodium aluminate solution must be greater than 170 to inhibit the large precipitation of SiO_(2).The higher the temperature,the more obvious the silicon precipitation is.The agglomeration efficiency,particle size and silicon precipitation affect each other.The better the agglomeration efficiency,the thicker the particle size,the less silicon precipitation is.Conversely,the greater the amount of silicon precipitation is.At the same time,the precipitation of silicon will also refine the aluminum hydroxide particle size and reduce the agglomeration efficiency.The degree of agglomeration efficiency is related to the amount of silicon precipitation and the particle size of aluminum hydroxide.With the increase of silicon precipitation,the agglomeration effect of the same particle size gradually deteriorated;The smaller the crystal size,the more significant the effect of silicon precipitation on the agglomeration efficiency,there is almost no effect on the agglomeration efficiency of grains greater than 8.98μm.The existence of organic matter and sodium oxalate impurities will directly or indirectly affect the precipitation of silicon.On the one hand,organic matter and sodium oxalate will make the particle size of the precipitated desilicate products become finer,and then induce the precipitation of silicon dioxide;On the other hand,organic matter and sodium oxalate will make the aluminum hydroxide particle size become finer,thus aggravating the

关 键 词：铝酸钠溶液 晶种分解 二氧化硅 析出行为 

分 类 号：TF821[冶金工程—有色金属冶金]