The effects of CaSO4 additive and burning temperature on the formation and properties of high-alkali clinker as well as their optimal control range were studied by means of chemical analysis, physical examination , XR...The effects of CaSO4 additive and burning temperature on the formation and properties of high-alkali clinker as well as their optimal control range were studied by means of chemical analysis, physical examination , XRD, DTA and EPMA. The results show that a proper addition of CaSO4 may convert alkalis to R2S04, reduce melt viscosity, considerably improve the forming environment of alite. during burning. hence the setting and hardening of clinker develop normally. If CaSO4 were too much , however , that excess SO3 with Al2O3 would dissolve into C2S to hinder C3S forming and produce K2SO4 ·CaSO4 ·H2O during hydratlon , to lead to quick setting of the paste. The optimal CaSO4 content expressed as SO3/R2O mole ratio in clinker is 0. 6-1. 0, A high temperature can decrease the riscosity and increase the rate of forming C3S nuclei , so not only helping overcome the harm of alkali but al,so supplementing imperfection of sulpfiate. It is better to burn a high alkali clinker with CaSO4 addition abore 1400℃.展开更多
文摘The effects of CaSO4 additive and burning temperature on the formation and properties of high-alkali clinker as well as their optimal control range were studied by means of chemical analysis, physical examination , XRD, DTA and EPMA. The results show that a proper addition of CaSO4 may convert alkalis to R2S04, reduce melt viscosity, considerably improve the forming environment of alite. during burning. hence the setting and hardening of clinker develop normally. If CaSO4 were too much , however , that excess SO3 with Al2O3 would dissolve into C2S to hinder C3S forming and produce K2SO4 ·CaSO4 ·H2O during hydratlon , to lead to quick setting of the paste. The optimal CaSO4 content expressed as SO3/R2O mole ratio in clinker is 0. 6-1. 0, A high temperature can decrease the riscosity and increase the rate of forming C3S nuclei , so not only helping overcome the harm of alkali but al,so supplementing imperfection of sulpfiate. It is better to burn a high alkali clinker with CaSO4 addition abore 1400℃.
