MODEL TEST STUDY ON TREATMENT OF BAUXITE TAILING SLURRY BY ADDING SAND STEP BY STEP COMBINED WITH QUICKLIME DRAINAGE AND SOLIDIFICATION

This paper aims to accelerate the drainage consolidation process of bauxite tailings slurry. It proposes a method of adding horizontal and vertical drainage consolidation and combined with quicklime consolidation. The increasing the drainage path and the ballast effect of the sand layer can result in that the tailing mud can achieve better drainage consolidation effect in a short period of time. The solidification degree of tailing mud can be further enhanced by adding quicklime. Based on the model test,this paper further analyzes the change characteristics of pore water pressure,volume water content and water content along the depth of tailings slurry in the process of drainage and consolidation in the model with and without adding sand. It draws the following conclusions: sand adding layer has obvious improvement on the self weight drainage and consolidation effect of tailings slurry; water content of tailings slurry in the model of adding sand layer is higher than that in the model of without adding sand layer. Meanwhile,it is found that the addition of sand can promote the strength growth of quicklime solidified tailing slime. This study can provide some reference for the practical application of bauxite tailing slurry,sand and quicklime drainage and solidification.