Feasibility study of the utilization of de-sulphurization slag as engineering filling materials

The mechanical and environmental characteristics of the mixture of de-sulphurization (DS) and blast furnace (BF) slags are investigated in this study. The experimental results show that the DS slag is a well-graded sandy soil. While achieving the maximum dry density, the required mixing ratio of the DS and BF slags is closed to 1. Similar results also existed in the case of shear strength, normal strength and CBR as compared with normal filling materials. In addition, the cured samples exhibit advantages of small void ratio, less compressibility, and higher CBR. Although pH value of slag is up to 11.3, it is reduced to 10 to approximately 11, if mixed with BF slag by 1:1 ratio. The total quantity of heavy metals contained in the DS, BF, and mixing product are quite low. It is concluded that the mixture of DS and BF slag can be utilized as an alternative engineering filling material with negligible environmental impact.