赤泥改性磷石膏作水泥缓凝剂

Using phosphogypsum modified by red mud as cement retarder

在对磷石膏直接应用于水泥中的危害分析的基础上,用赤泥对磷石膏在焙烧条件下进行改性。结果表明:磷石膏与赤泥按1∶5混合后,在800℃进行焙烧,保温2h后急冷,可消除磷石膏中有害杂质对水泥的不良影响,能代替天然石膏作水泥的缓凝剂,并且对水泥的强度具有增强效果。

If using phosphogypsum directly as a cement redarder,the performance of cement could be injured,therefore phosphogypsum should be modified by properly burned red mud.The tested results showed that the harmful effects of phosphogypsum on cement would be eliminated if it was kept at 800℃ for 2h and be quenched（the ratio of phosphogypsum to red mud was 1 to 2）.And then phosphogypsum,instead of natural gypsum,could be used as a cement retarder and meanwhile the cement strength could be improved.