Paste and Thickened Tailings (PTT) technology has the advantages of water-saving, dam safety, and environmentally friendly, which can improve tailings disposal and backfill operation. In the process of thickening preparation, the ultra-fine tailings particles are prone to form suspended water-locking flocs, which are severely detrimental to the underflow concentration improvement in the thickener. This study focuses on the deep cone thickener underflow density improvement. The high-precision CT scanning and three-dimensional reconstruction technology were used to explore the pore structure shear evolution to enhance underflow slurry dewatering behavior and reveal the thickening mechanism. Results show that when the shearing rate of the rake is two revolutions per minute (rpm), the concentration of tailings underflow rises from 59.2% wt to 68.5% wt, increases by 15.71%. The rake shearing breaks the pore structure of the flocs network, the pores quantity increases and the porosity decreases by 21.74%. After shearing, suspended particles fill the pores, the pore connectivity decreases by 26.74%, the absolute permeability decreases by 31.35%, the sealed pore water is discharged, and the bed slurry can be thickened. The study can improve the utilization rate of tailings (from classified tailings to whole tailings), make the thickening process going deep(raising high concentration slurry to paste slurry), and increase the backfill capacity (backfill underground goaf in time), so as to effectively reduce the tailing pond and goaf quantity.

糊状浓缩尾矿（PTT）技术具有节水、大坝安全、环保等优点，可改善尾矿处置和回填作业。在浓缩制备过程中，超细尾矿颗粒容易形成悬浮的锁水絮凝体，严重不利于浓缩器底流浓度的提高。本研究侧重于深锥浓缩机底流密度的提高。利用高精度CT扫描和三维重建技术探索孔隙结构剪切演化，增强底流泥浆脱水行为，揭示增稠机理。结果表明，当耙子的剪切速率为每分钟 2 转 (rpm) 时，尾矿底流浓度从 59.2% wt 上升到 68.5% wt，增长 15.71%。耙式剪切破坏了絮体网络的孔隙结构，孔隙量增加，孔隙率降低21.74%。剪切后悬浮颗粒充满孔隙，孔隙连通性降低26.74%，绝对渗透率降低31.35%，封闭孔隙水排出，床层泥浆可增稠。该研究可以提高尾矿利用率（从分级尾矿到全尾矿），使浓缩过程深入（将高浓度浆提高到糊浆），增加回填能力（及时回填地下采空区），从而有效减少尾矿库和采空区数量。剪切后悬浮颗粒充满孔隙，孔隙连通性降低26.74%，绝对渗透率降低31.35%，封闭孔隙水排出，床层泥浆可增稠。该研究可以提高尾矿利用率（从分级尾矿到全尾矿），使浓缩过程深入（将高浓度浆提高到糊浆），增加回填能力（及时回填地下采空区），从而有效减少尾矿库和采空区数量。剪切后悬浮颗粒充满孔隙，孔隙连通性降低26.74%，绝对渗透率降低31.35%，封闭孔隙水排出，床层泥浆可增稠。该研究可以提高尾矿利用率（从分级尾矿到全尾矿），使浓缩过程深入（将高浓度浆提高到糊浆），增加回填能力（及时回填地下采空区），从而有效减少尾矿库和采空区数量。