用低温煅烧法从粉煤灰中提取纳米Al_2O_3和SiO_2

Extraction of Nano-α-Al_2O_3 and SiO_2 from Fly Ash by Low Temperature Calcination

以粉煤灰为铝、硅源制备纳米α-Al2O3和SiO2(白炭黑),并对α-Al2O3进行表面改性实验研究,结果表明:粉煤灰和碳酸钠采用1∶1的配比,800℃低温保温2h,可得到自粉化较容易的霞石相。硅、铝分离盐酸浓度3.5mol/L,样品的产率较高。XRD衍射图谱及SEM分析得知:Al(OH)3经1100℃煅烧后,得到纯度达99.9%,比表面积为180m2/g,粒径达到纳米级的α-Al2O3;从硅胶可获得纯度达99.9%比表面积为374m2/g的SiO2(白炭黑)。改性研究表明:制备的α-Al2O3性能优良。

The nano-α-Al2O3 and SiO2 were prepared from fly ash, at the same time the surface modification of α-Al2O3 was researched. The results showed that when the rate of fly ash and Na2CO3 was 1 ： 1, the nephelite phase was easy to be gained with 800℃ low temperature roasting for 2h. When the consistency of HCl was 3.5 mol/L, the productivity of silica and alumina was more high. The XRD and SEM analysis showed that after the AI（OH）3 was calcined under 1100℃, the nano-α-Al2O3 with 99.9% purity and specific surface area of 180m^2/g was gained; the SiO2（white carbon） with 99.9% purity and specific surface area of 374m^2/g was gained from the colliod. The surface modification research showed that the performance of α-Al2O3 product was excellent.