Abstract:

In order to realize the resource utilization of phosphogypsum，the mine filling materials with the original phosphogypsum as the main raw materials and red mud as the alkaline activator were prepared，and the effects of the dosage of superplasticizer，cement and red mud on its properties were analyzed.The test results showed that when the water-binder ratio was 0.2 and dosage of polycarboxylate superplasticizer was 0.5%（mass fraction），the initial flowability of the slurry was about 230 mm，which met the property requirements of the filling material.When the cement content was increased from 0 to 10%，the 28-day compressive strength was increased from 2.03 MPa to 10.75 MPa，the initial fluidity was increased from 180 mm to 235 mm，and the strength retention rate was increased from 0.39 to 1.It was indicated that the cement content directly affected the strength，fluidity and water resistance of the filling material.When red mud admixture was increased from 0 to 5%，the 28-day compressive strength was increased by 50% and the strength retention was increased from 0.82 to 1.The excitation effect was obvious and had an opposite effect on the flowability of the materials.

Key words: phosphogypsum, red mud, alkali activation, filling material, compressive strength