熟料和水泥水化产物中Mg2+赋存状态显微分析

Microanalysis on Occurrence State of Mg2+ in Clinker and Hydrates

摘要:

文章通过扫描电镜观察了Mg2+在熟料和水泥水化产物中的赋存状态。结果表明：生长空间充裕的情况下方镁石可形成八面体晶体，受生长空间限制也可形成半自形晶或他形晶。方镁石晶粒尺寸主要分布在1μm～6.5μm之间，其中2.5μm～3.0μm之间晶体最多，最大粒径可达40μm。水化后期，Mg(OH)2晶体沿c轴方向生长速度快，颗粒厚度明显增加。固溶于熟料铝相中的MgO原位水化后碳化形成Mg6Al2CO3(OH)16·4H2O。从熟料中引入的Mg2+可以与Ca2+，Si4+等离子形成水化硅酸钙镁或者吸附于水化硅酸钙表面。

Abstract:

Occurrence state of Mg2+ in limestone, clinker, and hydrates were characterized with scanning electron microscopy and optical microscope. Results show: In ample space, periclase forms octahedron structure, and subhedral or anhedral crystal is formed in limited space. Grain size of periclase is mainly distributed between 1μm～6.5μm, most of the grains size ranges from 2.5 to 3μm, and the length of the largest particle is up to 40?μm. Mg(OH)2 particle thickness increase due to faster crystal growth rate along c axis at later age. Manasseite (Mg6Al2CO3(OH)16·4H2O ) is found in cement pastes, and the formation of it is as a result of in-situ hydration of aluminate containing MgO and carbonation consequently. Mg2+ originated form clinker also can form magnesium calcium silicate hydrate with Ca2+, Si4+, etc., or be absorbed on the surface of calcium silicate hydrate.