原料及配比对磷酸镁水泥性能影响的研究

Effects of Raw Materials and Compositions to the Properties of Magnesium Phosphate Cement

采用磷酸二氢铵、磷酸二氢钾和磷酸氢二铵作为引入磷的材料,不同细度的重烧镁砂以及不同掺量硼砂作为缓凝剂,通过测定其标准稠度需水量、凝结时间和抗压强度,结合X射线衍射分析和扫描电镜分析,研究了不同的磷酸盐原料及配比对磷酸镁水泥性能的影响。结果表明,磷酸盐水泥的凝结时间和强度随原料及配比变化有较大差异,磷酸二氢钾与磷酸二氢铵的性能较为接近,而采用磷酸氢二铵既加大了标准稠度用水量,也大幅度延长了凝结时间;同时采用磷酸氢二铵试样的强度相对也远小于采用磷酸二氢钾与磷酸二氢铵的试样;硼砂作为缓凝剂也可明显延长磷酸镁水泥的凝结时间。

Using potassium dihydrogen phosphate,diammonium hydrogen phosphate and ammonium dihydrogen phosphate as phosphorus introducing materials, dead burned magnesium oxide with different fineness as magnesium resource, borax as a retarder, magnesium phosphate cement （MPC） was prepared in this study. Water requirement of normal consistency and setting time of MPC were tested, the compressive strength of prepared samples were measured, as well analyze phase compositions and microstructure by XRD and SEM. The results show the setting time and strength of samples have significant difference with different raw materials. Using diammonium hydrogen phosphate as raw material not only can increase water requirment of normal consistency, but also significantly extend the setting time. The samples prepared by diammonium hydrogen phosphate also get lower strength than the sample prepared by ammonium dihydrogen phosphate and potassium dihydrogen phosphate. Borax as retard agent can obviously delay the setting time of magnesium phosphate cement.