膨润土常压低温焙烧法制备活性白土及其性能

Preparation and Properties of Activated Clay by Low-temperature Calcination at Atmospheric Pressure

以江西某地钙基膨润土为原料,浓硫酸为活化助剂,常压下低温焙烧活化制备高效活性白土,通过X射线衍射、紫外-可见吸收光谱等分析手段考察了不同浓硫酸/膨润土质量比、焙烧温度及焙烧时间对活化产物物相结构、脱色率及活性度的影响。结果表明:常压低温焙烧法中焙烧温度是影响活性白土性能的首要因素;在优化条件为浓硫酸/膨润土质量比25%、焙烧温度200℃,焙烧时间40 min时,制备得到的活性白土脱色率为99.22%,活性度为232 mmol/kg,游离酸含量为0.19%,其他性能也均满足我国行业标准各类型活性白土一等品要求。

Activated clay was prepared via low-temperature calcination at atmospheric pressure with Ca-bentonite as a raw material and sulfuric acid as an activator.The influences of mass ratio of sulfuric acid/bentonite,calcination temperature and calcination time on the phase structure,decolorization rate and activity of the activated products were investigated by X-ray diffraction,ultraviolet-visible adsorption spectroscopy and other analytical methods.The results show that the calcination temperature is a dominant factor affecting the performance of activated clay in this method.An activated clay with the decolorization rate of 99.22%,the activity degree of 232 mmol/kg and the free acid content of 0.19%can be obtained under the optimized conditions(i.e.,mass ratio of sulfuric acid/bentonite of25%,calcination temperature of 200℃,and calcination time of 40 min).Besides,this activated clay can be used as a first-class activated clay to meet the industrial requirements.