In order to improve the tailings utilization rate and realize full tailings’ filling in Huanggang iron mine in Inner Mongolia, a flocculation settlement system was added, which resulted in silting and consolidation of tailings in sand silts. Based on this, the reason for the deposition and caking of tailings was obtained through analysis, and a set of coarse and fine tailings bin filling system was proposed. The tailings of the plant were pumped to the filling station by slurry pump. Firstly, the tailings with large particle size difference were divided into coarse tailings and fine tailings by hydrocyclone so that the fine tailings entered the No. 1 sand bin and the coarse tailings entered the No. 2 sand bin. Then, flocculant was added by automatic flocculant dosing device to flocculate and settle the coarse and fine tailings, and then, it was mixed, stirred, and filled into the well. The results showed the following. (1) The particle size difference of tailings in Huanggang Iron mine increased and resulted in unstable flocs. The coarse tailings settled to the bottom of the silo before the fine tailings, and the compression time was too long, leading to the phenomenon of silting and consolidation. (2) Flocculation and settlement of coarse and fine tailings in different sand silos can avoid deposition and compaction of tailings in sand silos. (3) According to the different requirements of the concentration and ratio of the filling slurry, the proportion of coarse sand and fine sand in the filling slurry can be controlled by controlling the flow size of the coarse sand and fine sand chamber, to achieve the design of reasonable particle size composition and concentration requirements. The research results are expected to provide technical support and theoretical guidance for the construction of full tailings cemented filling system in Huanggang iron mine.

The problem of unstable full tailing sand concentration and dewatering in some mine filling systems has led to substandard bottom flow concentration of tailing sand concentration equipment, wide fluctuation ranges of filling concentration, substandard return water concentration at filling stations, and high flocculant addition cost. Through flocculation and sedimentation tests, the effect of the flocculant and sedimentation law and the effect of slurry concentration on sedimentation rate were studied, and the field application of the flocculant addition point model was verified. The results showed that (1) when the dose of the flocculant was added, the F1-type polyacrylamide as the flocculant made the best settling effect of the whole tailing sand in the test, as judged by comparing the falling rate of the clarified layer and the clarification degree of the supernatant. (2) With the increasing flocculant concentration, the settling speed of tailing sand gradually becomes slower; the range of the best settling concentration was 8%–18% of tailing sand concentration; and the concentration of tailing sand corresponding to the maximum solid flux was 10%–14%. (3) Relying on the site conditions of a domestic copper mine, the feed concentration was diluted from 20%–25% to 10%–12%, and the overflow water clarification test was less than 300 ppm, which verified the flocculant test and the correctness of the flocculant addition point model. The type and dosage of the flocculant as well as the feed concentration of the tailing slurry all have an effect on the flocculation and settling effect. The results of the study can provide some implications for the efficient flocculation and settlement of tailings in other mines.