摘要
目的研究盐类激发剂对无水硫酸钙水化激发机理,以提高无水石膏水化能力.方法测定无水硫酸钙水化率、不同时期溶液中钙离子浓度及利用X射线衍射谱分析方法对水化产物的物相组成进行分析,探讨了K2SO4掺量对无水硫酸钙水化的影响及水化激发机理.结果无水硫酸钙的水化率随着硫酸钾浓度的增加而增加.当硫酸钾浓度达到一定量时,K2SO4与CaSO4反应生成K2Ca(SO4)2.H2O,该复盐作为异质微粒,能有效地降低成核时的表面能位垒,使CaSO4.2H2O晶体优先在这些不均匀的地方形成,加速无水硫酸钙的水化.实验发现K2SO4与二水硫酸钙比无水硫酸钙容易生成复盐,因此反应过程不能用复盐理论来解释.结论CaSO4的水化过程不是按照复盐理论进行,而是按照溶解-成核-生长机理进行,CaSO4.2H2O结晶过程为非均匀成核析晶过程,K2Ca(SO4)2.H2O起成核催化剂作用.
The purpose of this paper is to study the activation mechanism ot salts on the hyclratlon of annydrous calcium sulfate. The hydration rate of CaSO4, the Ca^2＋ concentration in different periods and the phase composition of the hydration product by XRD and XPS are obtained respectively. The effect of K2SO4 quantity on the hydration of CaSO4 and the hydration excitation mechanism are discussed. Results show that the hydration rate of CaSO4 increases as the concentration of K2SO4 increases. When the content of K2SO4 reaches a certain quantity, K2SO4 reacts with CaSO4 to produce K2Ca（SO4）2· H2O, which as heterogeneous particles can effectively reduce the nucleation surface energy barrier, thus CaSO4 ·2H2O crystals form in these uneven areas first and the hydration of CaSO4 is accelerated. We also find K2SO4 reacts more easily with CaSO4· 2H2O to produce double salts than CaSO4, which can not be explained by double-salt theory. It can be concluded that the hydration process of CaSO4 does not conform with double-salt theory, but conform with dissolution-nucleation-growth mechanism;the CaSO4·2H2O crystallization process is non-homogeneous nucleation crystallization process while K2Ca（SO4）2· H2O acts as nucleation catalyst role.
出处
《沈阳建筑大学学报（自然科学版）》
EI
CAS
2008年第1期104-107,共4页
Journal of Shenyang Jianzhu University：Natural Science
基金
国家自然科学基金项目(20471046)
关键词
无水石膏
水化机理
激发
K2SO4
anhydrous calcium sulfate
hydration mechanism
excitated
K2SO4
