高铝煤矸石脱硅滤饼碱石灰烧结法制备氢氧化铝的实验研究

The Preparation of Aluminum Hydroxide from High-Alumina Gangue Desilication Residues Based on Soda Lime Sintering Method

采用碱石灰烧结法从内蒙古三道沟地区的高铝煤矸石中提取了氢氧化铝,实验原料经过碱液预处理,使其中的铝硅质量比(Al2O3/SiO2)由原来的0.86提高到2.21。实验研究了烧结过程中烧结温度为1100℃、1200℃、1250℃、1300℃以及生料中Na2O/Al2O3摩尔比为0.94～1.0,CaO/SiO2摩尔比为1.90～2.10时,对熟料烧结质量的影响。结果表明,在烧结温度为1200℃、Na2O/Al2O3摩尔比为1.0,CaO/SiO2摩尔比为2.1时,熟料的烧结质量最好,其中氧化铝的溶出率最高达到94%。最佳条件下得到的溶出液以一水铝石为晶种,在添加甲醇并于30℃下分解5h,铝酸钠溶液中氧化铝的分解率达到88.9%;扫面电镜结果显示,生成的铝氧水合物呈片状生长。

Alkali lime sintering method was used to prepare aluminum hydroxide from a coal gangue powder collected from the Sandao valley of the Inner Mongolia Autonomous.The weight ratio of Al2O3/SiO2 in the powder increased from 0.86 to 2.21 after treated with alkaline solution.The influences of different conditions,e.g.temperates of 1100,1200,1250 and 1300℃,Na2O/Al2O3 mole ratio from 0.94 to 1.0,and CaO/SiO2 mole ratio from 1.90 to 2.10,on the quality of clinker were investigated.The results indicated that the best quality clinker was obtained in the conditions of 1200℃,Na2O/Al2O ratio is 1.0 and CaO/SiO2 ratio is 2.1,in which the resolution ratio of alumina is up to 94%.By adding boehmite and certain methanol solution,the resolution ratio of alumina from sodium aluminate can be up to 88.9% after 5 hours at the temperature of 30℃.The scanning electron microscopy results show that the obtained product is slice shaped.