Influence of autoclaved pretreatment on the properties of phosphogypsum-based composite binders

2nd International Conference on Materials Science, Energy Technology and Environmental Engineering

材料科学;能源学;生态环境科学

Ren, Tingyan^1,2 ; Xi, Rong^1,2 ; Yang, Jiakuan^3

South China Institute of Environmental Sciences, Ministry of Environmental Protection of PRC, NO. 7 West Street, Yuancun, Guangzhou

510655, China^1

South China Environmental Sci-Tech Guangdong Co. Ltd, NO. 7 West Street, Yuancun, Guangzhou

510655, China^2

School of Environmental Science and Engineering, Huazhong University of Science and Technology, Wuhan

430074, China^3

关键词: Chemical activators;    Composite binders;    Crystalline phasis;    Phosphogypsum;    Pretreatment conditions;    Pretreatment process;    Saturated state;    Water-resistances;   

Others  :  https://iopscience.iop.org/article/10.1088/1755-1315/81/1/012015/pdf
DOI  :  10.1088/1755-1315/81/1/012015

来源: IOP

【 摘 要 】

Phosphogypsum-based composite binder (PGCB) has been made from autoclaved phosphogypsum (PG), fly ash, lime, Portland cement and a chemical activator. The influence of autoclaved pretreatment on the properties of PG and PGCB has been investigated. It was found that the crystalline phases of original PG could be transformed, the impurities of original PG also could be effectively removed by the autoclaved pretreatment process. Under the optimum autoclaved pretreatment conditions (autoclaving at 180 °C for 6 hours), the dry compressive strength of PGCB mortars after 28 days was 31.8 MPa and the ratio of the compressive strength in wet-saturated state to that in dry state (W/D) was 0.59. PGCB mortars show good properties and water resistance with the suitable autoclaved pretreatment.