轻烧白云石制备硫氧镁水泥及其制品性能

Preparation and properties of magnesium oxysulfate cement with light-burned dolomite

以白云石为主要原料,通过热分解得到轻烧白云石,以此为原料制备硫氧镁水泥,并对硫氧镁水泥进行抗压强度、耐水性测试及改性研究。结果表明:在810℃热处理2 h所得的轻烧白云石中活性氧化镁含量最高;当n(MgSO_(4)·7H_(2)O)∶n(MgO)∶n(H_(2)O)=20∶1∶12时,制备的硫氧镁水泥28 d抗压强度为34.5 MPa,软化系数为0.452;当掺入占轻烧白云石质量1.0%的柠檬酸改性剂时,硫氧镁水泥的28 d抗压强度、软化系数较未改性前分别提高了77%、80%。

This paper is an experimental study on preparation of magnesium oxysulfate cement with the dolomite as the main raw material.The magnesium oxysulfate cement was prepared with the best light-burned dolomite prepared by different thermal decomposition process.The compressive strength,water resistance test and modification study of magnesium oxysulfide cement are also carried out.The results show when the calcination temperature is 810℃,holding time is 2 h,the content of active magnesium oxide in the light-burned dolomite obtained is the highest.The molar ratio of MgSO_(4)·7H_(2)O∶MgO∶H_(2)O=20∶1∶12,the 28 d compressive strength of the magnesium oxysulfate cement prepared is 34.5 MPa,softening coefficient is 0.452.When the content of citric acid modifier is 1.0% of the light-burnt dolomite,the 28-day compressive strength and softening coefficient were increased by 77% and 80% respectively,compared with that before modification.