磷酸盐结合镁橄榄石-蛭石复合材料固化因素研究

Setting factors of phosphate bond forsterite-vermiculite composite material

以镁橄榄石、膨胀蛭石为主要原料,以磷酸盐为结合剂,常温下制备镁橄榄石-蛭石复合材料;采用SET-ARAM C-80微量热分析和XRD分析了结合系统的固化反应及其反应产物,研究困料时间、MgO种类及n(MgO)/n(P2O5)等对材料结合系统固化速率和结合强度的影响。结果表明,困料时间延长会导致试样强度降低;选用反应活性较低的烧结镁砂能更有效地提高材料的强度;n(MgO)/n(P2O5)增大,固化反应速率加快,材料结合强度增大,但n(MgO)/n(P2O5)过大,对材料结合强度反而不利。

Forsterite-vermiculite composite material was prepared from forsterite,expanded vermiculite as raw materials and phosphate as binder at room temperature.The effects of ageing time,magnesia type and MgO/P2O5 molar ratio on the setting rate and binding strength were investigated by using microcalorimeter（SETARAM C-80） and XRD.The result indicates that too long ageing time will lead to lower intensity.For better properties,sintered magnesia should be carefully chosen because of enormous crystal growth.With the increase of MgO/P2O5 molar ratio,reaction rate gradually rises,binding strength increases yet too large MgO/P2O5 molar ratio is disadvantageous to binding strength.