高含硼废液对硫铝酸盐水泥水化过程影响机理

Mechanism of Hydration Process of Calcium Sulfoaluminate in Highly Concentrated Borate Liquid Waste

研究了高含硼模拟液条件下硫铝酸盐水泥的水化反应特征、缓凝机理和使用氢氧化钙作为促凝剂的可行性。通过采用XRD、TG-DTG、微量热仪、SEM-EDS、EPMA等微观测试分析手段,表征了氢氧化钙对含硼模拟液条件下硫铝酸盐水泥水化过程和反应产物的影响。结果表明,在含硼模拟液中,硫铝酸盐水泥颗粒的表面会生成具有层状特征的硼化物,包裹水泥颗粒,阻碍其进一步溶解,延缓硫铝酸盐水泥水化。氢氧化钙的掺入能诱导硫铝酸盐水泥在含硼模拟液中优先生成含硼钙矾石,缓解硼酸根离子的缓凝效果,有效促进水泥水化反应;随着水化反应进行,含硼钙矾石会逐渐转变为钙矾石。

The delayed hydration process of sulfoaluminate cement by highly concentrated borate solution and the accelerated by calcium hydroxide are studied.The hydration products and process were characterized by TAM,XRD,TG-DTG,SEM-EDS and EPMA.The results show that hydration of SAC is strong delayed for the layer formation of boron contained mineral and the cement particles are stopped from the dissolvement.Adding calcium hydroxide could accelerate the hydration speed of cement in the borate solution.Boron exists as the formation of hexahydroborite and boron-contained ettringite(B-AFt).The B-AFt transforms into AFt with the undergoing of hydration process.