摘要
通过系统研究水洗和粉磨预处理前后煅烧磷石膏物理性能的差异,并结合X射线衍射和SEM分析水洗前后煅烧磷石膏水化产物含量和微观形貌的变化,阐释水洗预处理对磷石膏性能的影响机理,并将预处理后的煅烧磷石膏应用于石膏自流平。通过对比试验发现:水洗预处理可以有效去除磷石膏中的可溶性磷和氟,2 h抗压强度由4.7 MPa提高至5.7 MPa,白度由49.2%提高至69.4%;粉磨预处理可以有效改善磷石膏颗粒形貌和颗粒级配,进而提高其力学性能;未经水洗处理的磷建筑石膏水化1 d时生成的磷酸三钙和氟磷灰石含量分别为4.6%和0.8%(质量分数,下同),水洗处理后,磷石膏水化产物中未发现有害杂质的存在,二水石膏形貌由片状转变为棒状结构;掺入适量水泥可以改善石膏自流平浆体的pH和颗粒分布,有利于提高石膏自流平的流动性能和绝干强度。
The difference in the physical properties of calcined phosphogypsum before and after water washing and grinding was invested,the diffe-rence of contents of hydration products and microscopic morphology of calcined phosphogypsum before and after washing were also analysed with X-ray diffraction and SEM,then the influencing mechanism was interpreted.Besides,and the pre-treated calcined phosphogypsum was applied to the self-leveling.The comparative experiments results showed that the water washing pre-treatment could effectively remove the soluble phosphorus and fluorine in the phosphogypsum,the 2 h compressive strength increased from 4.7 MPa to 5.7 MPa,and the whiteness increased from 49.2%to 69.4%;grinding pre-treatment could effectively improve the morphology and particle gradation of phosphogypsum particles,which improved mechanical properties;the content of tricalcium phosphate(TCP)and fluoroapatite in phosphogypsum without washing pre-treatment hydrated for 1 day were 4.6 wt%and 0.8 wt%.After washing pre-treatment,the harmful impurities were not detected in the hydration products,and the morphology of dihydrate gypsum changed from sheet-like to rod-like structure;adding appropriate amount of cement could improve the pH and particle distribution of the gypsum self-leveling slurry,which was beneficial to improve the flow performance and absolute dry strength.
作者
刘猛
王庆
朱晨
顿鹏
刘勇
LIU Meng;WANG Qing;ZHU Chen;DUN Peng;LIU Yong(Wuhan Sanyuan Special Building Materials Co.,Ltd.,Wuhan 430080,China)
出处
《材料导报》
EI
CAS
CSCD
北大核心
2022年第S01期267-271,共5页
Materials Reports
关键词
磷石膏
水洗预处理
粉磨预处理
煅烧磷石膏
水化
石膏基自流平
phosphogypsum
washing pre-treatment
grinding pre-treatment
calcined gypsum
hydration
gypsum self-leveling
