The influence of pressure treatment technology on the pore filling effect of steel slag

CHENG Na; ZHAO Zhizhong; WANG Longfei; CHENG Daohua

doi:10.3969/j.issn.1672-0032.2026.01.009

Abstract：To address the issues of high porosity and low resource utilization efficiency of steel slag,a micropore filling technology is proposed.Based on the principle of pneumatic driving,the gas-liquid replacement process within the pores of steel slag is optimized,allowing the cement slurry to be efficiently and stably injected into the micropores of the steel slag.The quality increment of the steel slag before and after filling is tested under different pressure application methods,pressure application times,water-cement ratios,experimental temperatures,and steel slag particle sizes,studying the impact of micropore filling technology on the porosity of steel slag.The results indicate that with an increase in pressure application time,the overall mass increment of the steel slag increases.Negative pressure filling offers both safety and efficiency advantages;at 4 minutes of pressure application,the mass increment of steel slag filled under negative pressure is 20%greater than that of positive pressure.The final filling quality of the two pressure application methods tends to be the same,approximately 0.45 g.The high viscosity and poor fluidity of the cement slurry cause the mass increment of the steel slag to initially decrease and then slightly increase as the water-cement ratio increases.When the water-cement ratio is 0.8,the mass increment of the steel slag is 4.5 times than that at a water-cement ratio of 2.0.Increasing the experimental temperature from 25 ℃ to 50 ℃ accelerates the hydration agglomeration of the cement,resulting in a 37.5%decrease in the mass increment of the steel slag and a significant reduction in filling efficiency.The filling effect is most pronounced when the steel slag particle size is>5-10 mm,with a mass increment of 0.16 g.By filling the pores of the steel slag with cement products,interfacial homogenization can be achieved,significantly reducing porosity and improving gas-liquid replacement efficiency.