氟石膏和熟石灰碳化养护力学性能的研究

Study on mechanical properties of carbonation curing fluorogypsum and slaked lime

氟石膏是干法氟化铝或湿法氢氟酸生产的过程中排放的废渣,其主要成分是CaSO_(4)。为综合利用氟石膏,研究利用熟石灰和快速碳化养护去增强氟石膏的抗压强度和软化系数。采用DTA-TG、XRD和SEM-EDS对比分析了在不同氟石膏和熟石灰比例、不同水料比时,复合材料体系硬化后的性状。研究结果表明,当水料比为0.1,随着熟石灰掺量的增加,复合材料抗压强度由原来(未掺加熟石灰)的2.4 MPa增大到22.4 MPa。XRD、DTA-TG和SEM-EDS的测试结果表明,复合材料反应产物为二水石膏和碳酸钙,当熟石灰掺量为50%和70%时,碳酸钙的含量相对较高。熟石灰激发及快速碳化养护的协同作用下,氟石膏的力学强度及耐水性均得到提高,这为石膏基建筑材料的生产和研究具有较好的指导意义。

Fluorogypsum was the waste residue emitted during the production of dry-process aluminum fluoride or wet-process hydrogen fluoride.Its main component was CaSO_(4).In order to comprehensively utilize the fluorogypsum,this study used hydrated lime and rapid carbonation curing to enhance the compressive strength and softening coefficient of the fluorogypsum.The characteristics of the composite material system after hardening at different proportions of fluorogypsum and hydrated lime,as well as different water to material ratios,were analyzed using DTA-TG,XRD,and SEM-EDS.The research results showed that when the water to material ratio was 0.1,with the increase of hydrated lime content,the compressive strength of the composite material increased from the original(without hydrated lime) 2.4 MPa to 22.4 MPa.The test results of XRD,DTA-TG,and SEM-EDS showed that the reaction products of the composite material were gypsum dihydrate and calcium carbonate,and the content of calcium carbonate was relatively higher when the hydrated lime content was 50% and 70%.Under the synergistic effect of hydrated lime activation and rapid carbonation curing,the mechanical strength and water resistance of the fluorogypsum were improved,which has significant guiding significance for the production and research of gypsum-based building materials.