CAJ | 학술논문

介绍了1种采用煅烧-沥滤工艺从粉煤灰中提取氧化铝(Al2O3)的新方法.以碳酸钠(NaCO3)为活化剂,在900 ℃下煅烧,使粉煤灰中惰性的Al2O3转变成活性的可以溶出的铝盐.选用硫酸(H2SO4)为活性铝盐的溶出剂,在一定温度下溶出铝盐,使活化后粉煤灰中的Al2O3以液相形式溶出.用乙二胺四乙酸为络合剂有效除去铝盐[Al2(SO4)3]中的杂质铁(Fe3+)等,用蒸馏水洗涤除去钠(Na+)和其它可溶性杂质,有效提高Al2O3粉体的纯度.通过添加合适的分散剂、控制氢氧化铝[Al(OH)3]的结晶、干燥及煅烧的工艺条件,大大提高了Al2O3粉体的细度.通过X射线衍射、透射电子显微镜和N2吸附等技术分析获得的Al2O3粉体的组成与微观结构.通过以上工艺,获得Al2O3的提取率超过98%.将干燥后的Al(OH)3粉体在800 ℃下煅烧得到分散性好的纤维状γ-Al2O3,其纯度(质量分数)达99.6%.
개소료1충채용단소-력려공예종분매회중제취양화려(Al2O3)적신방법.이탄산납(NaCO3)위활화제,재900 ℃하단소,사분매회중타성적Al2O3전변성활성적가이용출적려염.선용류산(H2SO4)위활성려염적용출제,재일정온도하용출려염,사활화후분매회중적Al2O3이액상형식용출.용을이알사을산위락합제유효제거려염[Al2(SO4)3]중적잡질철(Fe3+)등,용증류수세조제거납(Na+)화기타가용성잡질,유효제고Al2O3분체적순도.통과첨가합괄적분산제、공제경양화려[Al(OH)3]적결정、간조급단소적공예조건,대대제고료Al2O3분체적세도.통과X사선연사、투사전자현미경화N2흡부등기술분석획득적Al2O3분체적조성여미관결구.통과이상공예,획득Al2O3적제취솔초과98%.장간조후적Al(OH)3분체재800 ℃하단소득도분산성호적섬유상γ-Al2O3,기순도(질량분수)체99.6%.
A new calcining-leaching process was used to extract high purity alumina (Al2O3) powders from fly ash in this study. The fly ash was mixed with soda (Na2CO3) and calcined at 900 ℃ to yield soluble aluminates. Subsequently the calcined ash was leached with sulfuric acid (H2SO4) to produce a solution containing aluminum. The unwanted metal ions including Fe3+ and Na+ were removed by ethylene diamine tetraacetic acid (EDTA) and water washing. Then added the proper dispersant, controlling the crystallization of aluminum trihydroxide precipitation, and the drying and calcining process was carried out, resulting in ultra fine Al2O3 powders with high purity. The characteristics of the Al2O3 powders were examined by means of X-ray diffraction, transmission electron microscope and the Brunauer, Emmet and Teller (BET) surface analysis method. The extraction efficiency of Al2O3 can surpass 98%by optimization of the calcination and lixiviation processes. Well-dispersed fibriform γ-Al2O3 powders were obtained by calcining at 800 ℃ and the purity of the ultra fine Al2O3 powders was more than 99.6%.