氧化镁与磷酸盐质量比对磷酸镁水泥水化历程的影响

发布时间：2018-01-06 10:39

本文关键词：氧化镁与磷酸盐质量比对磷酸镁水泥水化历程的影响　出处：《硅酸盐学报》2017年08期 　论文类型：期刊论文

【摘要】：研究了M/P比值(重烧氧化镁与磷酸盐的质量比)对磷酸镁水泥水化历程的影响,采用水化热动力学结合水化产物、微观形貌变化探讨了M/P比值对磷酸镁水泥水化作用机理。结果表明:增大M/P比值,会显著降低水化时吸热峰及放热峰的峰值。根据磷酸镁水泥水化放热速率的变化特点,可将水化放热过程划分为KH_2PO_4水解期、MgO溶解期、Mg(H_2O)6~(2+)增长期、MgKPO_4·6H_2O增长加速期、MgKPO_4·6H_2O增长减速期以及稳定期6个阶段。Knudsen与Kondo的水化动力学公式对于磷酸镁水泥水化体系的最终放热量及半衰期预测以及水化动力学研究具有良好的适用性,拟合相关系数高达0.99以上。M/P比值由2:1增至6:1,最终放热量及半衰期呈逐渐减小的趋势。磷酸镁水泥的水化是由结晶成核过程直接进入扩散过程,改变M/P比值,主要会对Mg(H_2O)6~(2+)增长期、MgKPO_4·6H_2O增长减速期以及水化稳定期产生影响。在第Ⅰ~Ⅳ阶段,反应物浓度及游离水含量变化是影响水化行为的主要原因。在第Ⅴ、Ⅵ阶段,水化体系中剩余MgO产生的隔断作用及反应物浓度的变化共同决定了水化速率。
[Abstract]:Study on the ratio of M/P (mass burn Magnesium Oxide and phosphate ratio) effect on magnesium phosphate cement hydration process, the heat of hydration dynamics with hydration products, microstructure changes of M/P ratio on magnesium phosphate cement hydration mechanism. The results show that the ratio of M/P increased, significantly reduced the endothermic peak and peak the hydration exothermic peak. According to the characteristics of magnesium phosphate cement hydration rate, hydration process can be divided into KH_2PO_4 hydrolysis period, MgO period, Mg (H_2O) 6~ (2+) MgKPO_4 growth, 6H_2O growth accelerated phase, MgKPO_4 6H_2O hydration kinetics equation and a slowdown in growth period stable period of 6 stages of.Knudsen and Kondo in magnesium phosphate cement hydration system at heat and the half-life of prediction and hydration kinetics study has good applicability, fitting correlation coefficient is up to 0.99.M/P ratio from 2:1 to 6:1, The final heat and half-life decreased. Magnesium phosphate cement hydration by nucleation process directly into the diffusion process, change the ratio of M/P, mainly on Mg (H_2O) 6~ (2+) MgKPO_4 - 6H_2O growth period, growth period and impact deceleration hydration stability. In section I ~ phase IV, change of reactant concentration and free water content are the main reasons that affect the hydration behavior. In Chapter V, VI stage, water system in surplus generated by the MgO partition and reactant concentration determines the rate of hydration.

【作者单位】：后勤工程学院化学与材料工程系;
【基金】：国家自然科学基金项目(51272283)
【分类号】：TQ172.1
【正文快照】： DAI Fengle,WANG Hongtao,DING Jianhua,JIANG Zichao(Department of Chemistry and Engineering,Logistical Engineering University,Chongqing 401311,China)Received date:2016 11 27.Revised date:2017 05 28.First author:DAI Fengle(1992 ),male,Master candidate.

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