磷石膏基水硬性胶凝材料是近几年发展起来的一种以磷化工业副产物磷石膏为主要原料的新型建筑材料。与传统硅酸盐和矿渣水泥相比,磷石膏无活性不能直接作为胶凝材料,使用前必须对其进行改性。针对目前磷石膏基胶凝材料凝结时间长、早期强度低等缺点,研究了材料组成配比及外加剂对凝结时间和早期强度的影响,获得了磷石膏基胶凝材料的改性方法。当矿渣粉（KF）和硅基纳米粉末（WS）质量比为3∶17,水玻璃（NS）、富铝盐（NA）和高效聚羧酸减水剂（JS）的质量分数分别为0.3%、0.7%和0.3%时,可将其初凝时间控制在130~260 min、终凝时间控制在280~600 min;胶砂早期抗折强度3 d达3.5 MPa以上、7 d达5 MPa以上;早期抗压强度3 d达20 MPa以上、7 d达35 MPa以上。改性后的磷石膏基胶凝材料可替代25%~40%及以上普通硅酸盐水泥应用于建筑材料领域。

Phosphogypsum based hydraulic cementitious material is a new building material with phosphogypsum of byproduct of phosphating industry as the main raw material.Compared with traditional portland cement and slag cement,phosphogypsum is inactive and cannot be directly used as cementitious material,and must be modified before use.In view of the shortcomings of the current phosphogypsum-based cementitious materials,such as long setting time and low early strength,the effects of material composition and admixture on setting time and early strength were studied to obtain modification method of phosphogypsum based cementitious material.When the mass ratio of slag powder （KF） to silicon-based nano powder（WS） was 3:17 and the mass fractions of sodium silicate（NS）,aluminum rich salt（NA） and high-efficiency polycarboxylate water reducer（JS） were 0.3%,0.7% and 0.3% respectively,the initial setting time could be controlled at 130~260 min and the final setting time could be controlled at 280~600 min.The early flexural strength of mortar was more than 3.5 MPa in 3 d and more than 5 MPa in 7 d.The early compressive strength was more than 20 MPa in 3 d and more than 35 MPa in 7 d.The modified phosphogypsum based cementitious material could replace 25%~40% or more ordinary portland cement in the field of building materials.