基于干扰床层密度分布调控的难选粗煤泥强化分选研究

The efficient separation of coarse slime between the lower limit of large-diameter heavy medium cyclone and the upper limit of flotation is a guarantee for coal preparation plant to maximize the recovery. In recent years, teetered bed separator has been widely applied due to the simplicity and low separation density. However, the teetered bed separator can’t achieve ideal separation performance for the refractory coarse slime with high content of near-density particles. .This subject is based on the theory that particles can be stratified according to their specific gravity. The method of regulating distribution of bed density was introduced, the closure-sampling laboratory separation system, interference bed density measurement system, high speed dynamic camera system for observing particle motion, electrical resistance tomography system for scanning concentration change, Labasys multiphase flow velocity and concentration test system were adopted. Combined with the numerical simulation for the interaction between particle flow and fluid flow by CFD-DEM coupling algorithm, the effect of operating parameters on the bulk concentration and distribution were explored, the bed density distribution and regulation were revealed, the mechanism of regulating the bed density to improve the tramp of refractory coarse slime was clarified, the particle dynamics model under the regulation of bed distribution was established to provide theoretical basis and technical support for the efficient separation of refractory coarse slime.

介于大直径重介旋流器有效分选下限和浮选有效分选上限之间的粗煤泥的高效分选是选煤厂精煤回收率最大化的重要保证之一，近年来干扰床分选以操作简单、分选密度低的优势得到大规模应用。但是对于临近分选密度含量高的难选粗煤泥，干扰床分选机难以达到比较理想的分选效果。本课题以颗粒按密度分层理论为依托，引入床层密度分布调控的方法，采用截流取样实验室分选系统、干扰床层密度测试系统、高速动态摄像系统观测颗粒运动、电阻层析成像系统断层扫描浓度变化、Labasys多相流速度浓度测试系统，结合CFD-DEM耦合算法对颗粒运动和流体流动相互作用的数值模拟等手段，探索操作参数对床层固体容积浓度和物料组分分布的影响规律，揭示床层密度分布及其调控规律，阐明床层密度调控对难选粗煤泥颗粒错配分层的改善机理，建立基于床层分布调控作用下的难选粗煤泥颗粒动力学模型，为难选粗煤泥的高效分选提供理论依据和技术支持。

介于大直径重介旋流器有效分选下限和浮选有效分选上限之间的粗煤泥的高效分选是选煤厂精煤回收率最大化的重要保证之一，近年来干扰床分选以操作简单、分选密度低的优势得到大规模应用。但是对于临近分选密度含量高的难选粗煤泥，干扰床分选机对难以达到比较理想的分选效果。本课题以颗粒按密度分层理论为依托，引入床层密度分布调控的方法，采用截流取样实验室分选系统、干扰床层密度测试系统等手段，探索操作参数对床层固体容积浓度和物料组分分布的影响规律，揭示床层密度分布及其调控规律，阐明床层密度调控对难选粗煤泥颗粒错配分层的改善机理，建立基于床层分布调控作用下的难选粗煤泥颗粒动力学模型，通过引入附加脉动水流对床层密度分布进行调控，从而优化难选粗煤泥的分选，在采选机械化高度发达的今天，对于约占30%的难选稀缺炼焦煤选煤厂，具有非常重要的应用价值。