2CaSO_4·K_2SO_4复盐对硅酸盐水泥熟料烧成及水化的影响  

Effect of 2CaSO_4·K_2SO_4 Double Salt on Sintering Performance and Hydration of Portland Cement Clinker

作　　者：黄黎明 杨正宏[1,2] 宋文娟[1,2] 李好新[1,2] 

机构地区：[1]同济大学材料科学与工程学院,上海201804 [2]同济大学先进土木工程材料教育部重点实验室,上海201804

出　　处：《硅酸盐学报》2017年第11期1629-1634,共6页Journal of The Chinese Ceramic Society

基　　金：国家自然科学基金重大项目(51132010)

摘　　要：通过高温合成2CaSO_4·K_2SO_4复盐,再将其以不同掺量掺入Ca CO3、Si O2、Al2O3和Fe2O3组成的水泥生料中,在1 450℃煅烧至水泥熟料中f-Ca O小于1%。研究了2CaSO_4·K_2SO_4复盐对水泥熟料高温烧成过程、矿物组成与结构及水化性能的影响。结果表明:2CaSO_4·K_2SO_4降低了Ca CO3起始分解温度,改变了熟料的熔融液相性质,增加了液相量,降低了矿物的最低共熔温度;2CaSO_4·K_2SO_4提高了熟料中C_3S含量,降低了C_3A和C_4AF含量,烧成熟料中C2S晶型主要为β型,也存在少量γ型,2CaSO_4·K_2SO_4使C_3S晶型由R型向M_1型转变,但晶型不随掺量改变。复盐的掺入缩短了熟料水化的诱导期,促使第二水化放热峰最大值提前出现,2CaSO_4·K_2SO_4掺量增加抑制了熟料前期和后期水化性能,提高了中期水化放热速率。The 2CaSO4-K2SO4 was firstly synthesized via high temperature reaction, and then mixed with CaCO3, SiO2, Al2O3 and Fe2O3 as cement raw materials. Those raw materials were sintered at 1 450 ℃. Influence of 2CaSO4·K2SO4 on the sintering process, mineral composition and polymorphs, and hydration properties of sintered clinker was investigated. The results show that the 2CaSO4.K2SO4 reduces the initial decomposition temperature of CaCO3, improves the melt liquid phase properties of raw materials, increases the content of formed liquid phase and reduces the minimum eutectic temperature of raw materials. The 2CaSO4·K2SO4 increases the content of C3S and reduces the contents of C3A and C4AF in the clinker. The polymorph of C2S in the clinker is mainly β-type, and there exists a small amount of γ-type, the polymorph of C3S is changed from R to MI in the presence of 2CaSO4·K2SO4, but its polymorphism does not change with the increased content of 2CaSO4·K2SO4. The 2CaSO4·K2SO4 reduces the hydration induction period of clinker and increases the maximum value of the second hydration exothermic peak. The initial and late hydration properties of clinker are inhibited due to the 2CaSO4·KESO4, but the hydration rate of clinker in the medium term is increased.

关 键 词：硫酸钾钙复盐 高温烧成 矿物成分 晶型 水化性能 

分 类 号：TQ172[化学工程—水泥工业]