钙矾石形成机理的研究

采用液相离子浓度测定与固相物相分析的方法，分析了离子浓度变化规律与钙矾石形成的关系，考察了矿物种类与含量、石灰浓度、二不石膏掺量对钙矾石形成的影响。结果表明：钙矾石形成是由[AI(OH)6]^3-八面体，铝氧八面体与钙多面体交替排列成形钙铝多面柱与SO4^2-进入柱间沟槽3个过程串联形成，其中速率最慢的[AI(OH)6]^3-形成过程为钙矾石形成的控制步骤。形成钙矾石诸离子中，[AIO2^-]最低，是影响钙矾石形成速率的最活跃因素。

STUDY ON THE MECHANISM OF ETTRINGITE FORMATION

The law of ionic concentration change in liquid phase and relation with ettringite formation were investigated by measuring ionic concentration and analyzing solid phase composition. The effects of calcium aluminate, lime and gypsum addition on ettringite formation were also studied. Experimental results show that ettringite formation consists of three reactions including the formation of [Al(OH) 6] 3- octahedra and formation of Ca-Al polyhedra in which Ca and Al polyhedra arrange alternately, as well as SO 2- 4enters in the channel of polyhedra. The reaction of [Al(OH) 6] 3- formation, which is the slowest reaction, controls ettringite formation. Of all ions from which ettringite is formed, AlO - 2 is the most active factor and its concentrition is the lowest.