Abstract: Cemented-tailing backfills were produced by taking unclassified tailings of Zhongguan Iron Mine as filling aggregate, and ordinary Portland cement as cementing agent. Physicochemical properties of unclassified tailings were analyzed, quantitative relationships between backfill strength and cement-tailing ratio, slurry concentration, and curing age were discussed by using single-factor four-level experiment, and sensitivity of backfill strength to these factors were also studied. The results show that, unclassified tailings of test, whose median diameter, alkalinity coefficient and activity coefficient are 14. 2 μm, 2. 31 and 2. 12 respectively, belongs to alkaline super-fine tailings with high activity. Strength of full tailings cemented backfill follows exponential function with cemented-tailing ratio and slurry concentration, but linear function with curing age, and the the corresponding correlation coefficients are 0. 97, 0. 96 and 0. 92 respectively. Sensitivity of backfill strength to curing age is the maximum, followed by cement-tailing ratio, and slurry concentration is the minimum.

Key words: filling method;super-fine unclassified tailings;cemented backfill;strength character;quantitative relation