摘要：采用硫酸作酸浸剂、Na₂S₂O₄作还原剂的方法对高岭土进行了除铁增白实验,考察硫酸的质量分数、温度、浸出时间、Na₂S₂O₄的用量、草酸用量等因素对除铁增白效果的影响,得出最佳除铁增白方案。最佳除铁增白方案为:在矿浆中高岭土与水的质量比为20∶100时,硫酸的质量分数为20%、温度为80℃、浸出时间为2h、Na₂S₂O₄用量为0.5g、草酸用量为1.0g。经除铁增白后,高岭土中的Fe₂O₃的质量分数由原来的2.098%降为0.35%,白度由原来的56.4%提高到81.5%。

关键词：高岭土；除铁；漂白

Abstract：The iron removal and bleaching experiment on kaolin was made by the method of vitriol as soaking agent and Na₂S₂O₄ as reducer. The factors that influenced iron removal and bleaching result were investigated， including sulfuric acid concentration， temperature， soaking time， dosage of Na₂S₂O₄， dosage of oxalic acid， and so on. The best iron removal and bleaching project was worked out. When the mass ratio of kaolin and water was 20∶100 ， the mass fraction of sulfuric acid was 20% ， temperature was 80 ℃， soaking time was 2 h， dosage of Na₂S₂O₄ was 0.5 g and dosage of oxalic acid was 1.0 g. After iron removal and bleaching， the mass fraction of Fe₂O₃ in kaolin was dropped from 2.098% to 0.35% and the kaolin whiteness was increased from 56.4% to 81.5%. 

Keywords：kaolin； iron removal； bleaching