采用NaAlO2-CO2连续中和法制备拟薄水铝石

采用NaAlO2-CO2连续中和方式制备拟薄水铝石，研究了连续中和-母液老化和连续中和-净水老化2种工艺的规律，探讨了不同中和pH值、老化方式、老化温度以及老化时间对产物性质的影响。采用XRD、BET、XRF、TEM等手段表征了产物的晶相、相对结晶度、晶粒尺寸、孔结构、比表面积、杂离子含量以及晶粒的形貌和堆积方式。结果表明，连续中和与间歇中和工艺反应规律相似，但连续中和工艺更易生成丝钠铝石；采用连续中和-净水老化工艺可有效避免丝钠铝石的生成；随着中和pH值下降，拟薄水铝石晶粒堆积更加致密，其焙烧所得?-Al2O3的孔容和比表面积均有所降低，最可几孔直径增大。

Preparation of Pseudo-Boehmite by Continuous Neutralization of NaAlO2-CO2 Method

Continuous neutralization-aging in mother solution process and continuous neutralization-aging in deionized water process for pseudo-boehmite preparation were investigated. The effects of neutralization pH value, aging mode, aging temperature, and aging time on the properties of prepared pseudo-boehmite were investigated. XRD, BET, XRF, TEM were applied to analyze the crytal form, crystallinity, crystal particle size, pore structure, specific surface area, impurity ions, morphology and packing form of crystal particles of products. The results showed that the pattern of continuous neutralization was similar to batch neutralization, but with a larger probability of dawsonite formation. Continuous neutralization-aging in deionized water process was better for avoiding the dawsonite formation. Rod-like particles of prepared pseudo-boehmite were more closely packed, and the pore volume and specific surface area of ?-Al2O3 obtained from pseudo-boehmite calcination deceased, and its most probable pore diameter increased with the decrease of neutralization pH value.