Study on preparation of inorganic binder stabilized material with large dosage of phosphogypsum

다국어 초록 (Multilingual Abstract)

With the rapid development of the phosphorus chemical industry, a large amount of phosphogypsum (PG) is discharged. The impurities in PG pollute the surrounding soil, the groundwater and the air in the long-term storage. In this paper, PG as the main raw material is used to study the stable material of inorganic binder in the condition of large dosage of PG. With PG and graded gravel as stabilized materials, and cement and fly ash as binder, materials are mixed to determine the influence of PG ratio and the amount of activator on the mixture. The results show that the mechanical strength of the mixture increased first and then decreased with the increase in the proportion of PG replacing graded gravel in the mixture. The activator significantly improves the properties of the material system and makes a significant contribution to the curing of PG. The best ratio of pretreated PG: cement: fly ash: aggregate is 50:6:5:39. The amount of activator added by the external mixing method is 0.3%, which can make the unconfined compressive strength reach 4.1 MPa after 7d. Finally, water-soluble phosphorus leaching experiment is conducted for all the samples. The results show that phosphorus leaching is so little that no secondary pollution of the environment is caused.