Effect of pumping water-reducing agents on uniaxial compressive strength and flow performance of full tailing and waste rock cemented backfill

To address the issues of uneven distribution of uniaxial compressive strength in backfill and poor quality of high-density cemented backfill containing coarse aggregate in the stopes of the Second Mining District of Jinchuan Nickel Mine, experimental studies were conducted on the effects of the type and dosage of pumping water-reducing agents on the uniaxial compressive strength and vibration spreading degree of full tailings and waste rock cemented backfill. The physicochemical properties and particle size distributions of the waste rock and tailings were analyzed. The technical parameters from the industrial production of the full tailings and waste rock cemented backfill system at Jinchuan Nickel Mine were employed. Tests were conducted to investigate the uniaxial compressive strength and vibration spreading degree of the backfill with different dosages of pumping water-reducing agent under various curing ages. The influences of different types and dosages of water-reducing agents on the backfill properties were studied separately. The results indicate that when adding a pumping water-reducing agent with 0.3 %–1.2 % cement content, the 3 d, 7 d, and 28 d uniaxial compressive strengths are all significantly improved. The AK-type aliphatic water-reducing agent with 0.3 % cement content is determined to be a relatively reasonable addition amount.