Paste backfilling material prepared with red mud from sintering process and unclassified tailings

To solve the problems of environmental pollution brought by the stockpiling of unclassified tailings and red mud, a mine backfilling material was prepared with red mud from sintering process, unclassified tailings and other solid wastes. The experimental results show that the optimal mass proportions of the cementing agent are red mud 49.2%, slag 32.8%, clinker aggregate 10%, and plaster 8%; the strength of the backfilling material block reduces sharply with the increase of the unclassified tailings addition; the hydration products of cttringite and C-S-H gel generated in the test block at the early stage of hydration help for the early strength. Differential scanning calorimetry-thermo gravimetrie (DSC-TG) analysis shows that the test block concretes lots of water at the early stage. The prepared paste backfilling material has the characteristic of high early strength, large water concretion, high quantity wastes utilization, etc., and it can meet the requirement of mine backfilling.