Research on the sedimentation, concentration and strengthening process and mechanism of ultrafine tailings

Ultrafine tailing sand was a solid waste generated by the ore dressing process, which seriously affects the efficient large-scale production of mining enterprises due to its fine particle size and slow settling speed. In response to the difficulty of settling and concentration of ultrafine tailings, two kinds of technology for strengthening sedimentation and concentration of tailings were proposed in this paper, namely process strengthening and structure strengthening. In the process strengthening approach, a novel flocculant CF, exhibits optimal sedimentation performance at a concentration of 45% and a dosage of 120 mg/L, achieving a maximum sedimentation velocity of 2.93 mm/s. In the structural enhancement approach, a new deep cone concentrator was designed, which, at a feed rate of 400 mL/min and a scraper rotation speed of 5 rpm, results in a bottom flow concentration of 70.53% after 30 min of sedimentation, demonstrating superior sedimentation concentration performance. The type and content of water in the tailing sand were investigated using Nuclear Magnetic Resonance (NMR), and adsorbed water, pore water and free water were mainly present in the tailing sand, and the active water content in the tailing sand decreased significantly and migrated to more stable water as the settling proceeded.