利用粉煤灰制备高纯氧化铝纳米粉体的研究

地球资源的充分利用已成为当今人们普遍关注的问题之一。采用苏打(Na2CO3)焙烧沥滤工艺从粉煤灰烧结料浸出液中制取了高纯超细氢氧化铝,进而通过控制煅烧制得氧化铝纳米粉体。对制备氧化铝的活化过程、浸出过程和煅烧过程的化学原理与工艺控制进行了研究与分析,确定了制备高纯氧化铝纳米粉体的较佳实验条件和工艺参数。应用XRD、TEM、BET和ICP等微观分析手段对所得Al2O3 的形态、结构和纯度进行了表征。结果表明:焙烧、水煮粉煤灰和Na2CO3,并精确调节溶出液的pH值,可使超细的氢氧化铝沉淀析出。在85 ℃充分干燥后,分别于800 ℃、1 100 ℃煅烧2 h,得到晶型结构分别为γAl2O3 和αAl2O3 的氧化铝纳米粉体,其形态为纤维状和球状,比表面积分别为238.9 m2/g和16.82 m2/g,平均粒径为20~40 nm,纯度大于99.9%。

Extracting high-purity nano-alumina from fly ash

Today the recycle of the earths resources is a vital problem,which is of global interest. We have extracted high-purity nano-alumina from calcined fly ash using a baking soda (Na_2CO_3) method. We have prepared the ultra-fine aluminum hydroxide powders by a liquid chemical method, and conducted research on the processes of activation, lixiviation and calcination, we have obtained better technological conditions and preparing parameters. The configuration, structure and purity of the sample have been investigated by XRD, TEM, BET and ICP. The results indicate that the ultra-fine aluminum hydroxide is prepared when the fly ash and soda are calcined, and poached, and the pH of the lixivium is accurately adjusted; that the fibriform γ-Al_2O_3 with 20~30 nm in diameter and 238.9 m~2/g in specific surface area is obtained when the aluminum hydroxide is dried at 85 ℃ and calcined at 800 ℃; and that the spherical α-Al_2O_3 with 30~40 nm in diameter and 16.82 m~2/g in specific surface area is obtained when calcined at 1 100 ℃. The purity of the powders is higher than 99.9 percent.