Abstract:

To address the significant spatiotemporal fluctuations in suspended solids (SS) concentration in mine water and the lack of theoretical basis for surface loading design in pre-sedimentation pools, which lead to unstable treatment efficiency, the physicochemical characteristics of SS were analyzed through static zoning sampling. Concentration gradient settling experiments were conducted to explore the influence of SS concentration on settling performance and optimized pre-sedimentation strategies. Results indicated that particles in mine water were primarily composed of clay minerals (44%-58%),coal powder (24.7%-38.1%), and a small amount of non-clay minerals, with a density of 1.75-1.79 g/cm³. Notably, 90% of the particles had size <50 μm. SS removal was synergistically governed by initial concentration and particle size. In high-concentration systems (≥1 000 mg/L), frequent particle collision triggered a chain reaction of “collision-adhesion-reconstruction”, thereby effectively enhancing the removal efficiency, and increasing the proportion of particles with settling velocities >1 cm/min by 25%-60%. Residual SS after 120 min of settling were dominated by fine particles(<10 μm), whose low settling rates constrained the system to enter a slow-settling equilibrium phase. The E _T -u curve demonstrated that settling efficiency in low-concentration systems was highly sensitive to surface loading. By regulating surface loading (0.172-0.577 m³/(m²·h)), the pre-sedimentation pool achieved over 90% removal of particles >10 μm.

Key words: coal mine water, suspended particles, particle size distribution, settlement performance, surface loading, pre-sedimentation tank

摘要：

针对矿井水悬浮物浓度时空波动大、预沉池表面负荷设计缺乏理论依据，导致处理效能不稳定的问题，通过对煤矿矿井水静置分区取样，解析了悬浮物物化特性，并基于浓度梯度沉降实验，探究了悬浮物浓度对体系沉降性能的影响规律以及预沉优化路径。结果表明，矿井水中颗粒物主要由黏土矿物（44%~58%）、煤粉（24.7%~38.1%）及少量非黏土矿物组成，密度为1.75~1.79 g/cm³，90%颗粒的粒径<50 μm。矿井水悬浮物去除效率受初始浓度与颗粒粒径协同调控，高浓度体系（≥1 000 mg/L）颗粒碰撞频率高，触发“碰撞-黏附-重构”链式反应，使去除率有效提升，沉降速率>1 cm/min的悬浮物体积分数增加25%~60%。沉降120 min后残留悬浮物以粒径<10 μm微细颗粒为主，受其低沉降速率限制，体系进入缓沉平衡阶段。E _T~u曲线显示，低浓度体系沉降效率对表面负荷敏感性较高，通过调控表面负荷〔0.172~0.577 m³/（m²·h）〕，可实现预沉池对粒径>10 μm颗粒的去除率达到90%以上。

关键词: 煤矿矿井水, 悬浮颗粒物, 粒径分布, 沉降性能, 表面负荷, 预沉池

CLC Number: 

• X703