以钙基膨润土为原料,采用体积分数为15%的硫酸、盐酸与草酸饱和溶液组成的混酸为酸化试剂,通过轮碾法制备高效活性白土。结果表明,混酸浓度、固酸比、碾压时间、含水率和还原剂用量是影响活性白土活性度、脱色率和相对白度的主要因素。当混酸体积分数为15%、固酸比为4:1、含水率为22%、碾压时间为40min、还原剂用量为膨润土物料质量的0.8%时,可制备出活性度为204,脱色率为96%,相对白度为82的高性能活性白土。

Taking Ca-bentonite of Zhanyi County, Qujing City, Yunnan Province as the raw material, after drying, the moisture content is less than 5%, and broken into particles of 3—5mm. Acidification reagents are consisted of the volume fraction of 15% sulfuric acid, hydrochloric acid and oxalic acid saturated solution. Add acidification reagents to the wheel grinding machine for rolling. After a certain period of time, add Ca(OH)2 and adjust the material to 5 or 6 pH values, meanwhile add reductant sodium dithionite (Na₂S₂O₄). After 5 minutes, stop working and discharging, drying the material at 110℃, preparing of high efficient active floridin after crushing. The research results indicate that the main factors influencing the activity and decolorization ratio of floridin include mixed acid concentration, solid-to-acid ratio, rolling time, moisture content and reducing agent dosage. When the mixed acid volume fraction is 15%, solid-to-acid ratio is 4:1, moisture content is 22%, rolling time is 40min and reducing agent dosage is 0.8%, it is possible to prepare the high-efficient active floridin with active degree being 204, decolorization ratio being 96%, the relative brightness being 82.