Al(H_2PO_4)_3溶液表面包覆提高镁钙熟料抗水化性能研究

Research on Hydration Resistance of MgO-CaO Clinker Surface Treated through Al(H_2PO_4)_3 Solution

采用浸渍法,以Al(H2PO4)3,Al(H2PO4)3 H3PO4和H3PO4三种溶液为浸渍剂,对镁钙熟料进行表面处理,研究其抗水化性能的变化规律。结果表明,采用Al(H2PO4)3溶液取代或部分取代H3PO4溶液,控制合适的浸渍浓度、反应温度和热处理温度,因在镁钙熟料表面形成了以难溶或不溶于水的Ca2P2O7、Ca3(PO4)2、Al(PO3)3、AlPO4为主的保护膜,同时因为钙和铝的磷酸盐相互交叉构成网络结构,改善了膜的强度及对熟料颗粒表面的粘结性,从而获得优于H3PO4溶液处理的抗水化效果;处理后的镁钙熟料水化增重率和粉化率:Al(H2PO4)3 H3PO4溶液分别为0.35%和2.8%,Al(H2PO4)3溶液分别为0.54%和3.45%,而H3PO4溶液分别为0.41%和5.1%。

By Applying the dipping method, the influence of different dipping agents, Al(H2PO4)3 solution, Al(H2PO4)3H3PO4 solution and H3PO4 solution,on the hydration resistance of MgOCaO clinker has been investigated in the paper. The results show that by replacing or partly replacing H3PO4 solution with Al(H2PO4)3 solution and controlling the concentration and temperature of the solution as weel as the heat treatment temperature, the hydration resistance can be significantly improved due to the formation of cocontinuous and waterinsoluble coating such as Ca2P2O7, Ca3(PO4)2, Al(PO3)3 and AlPO4, which benefits the properties of mechanical strength and cohesive strength.The mass increment rate and pulverization rate which are 0.35% and 2.8% respectively when treated through Al(H2PO4)3H3PO4 solution, 0.54% and 3.45% when treated through Al(H2PO4)3 solution, are better than those when treated in H3PO4 solution which are 0.41% and 5.1%.