基于细煤泥稳态分选的旋流微泡浮选柱内三相流体力场动力学特性研究

Increase of mechanical coal mining and promotion of heavy medium coal preparation process lead to higher coal slurry concentrate going into flotation in coal preparation plant; furthermore, the widely used "heavy separation + coarse slime separation + flotation" process lead to finer coal slime with worse floatability. Nowadays, it is urgent to solve the problem of domestication of key equipment of 10 Mt/a super-huge type coal preparation plant in China's coal industry. Clean coal recovery and quality is greatly influenced by fine slime separation precision and recovery. Micro-bubble cyclone flotation column has been proved to have noteworthy advantages in fine and micro-fine coal slime separation, however, it is urgent to tackle some key technological problem to achieve steady state separation of coal slime with high concentration and fine size and to get suitable flow distribution within the large size flotation column. This project will reveal flow distribution law within the flotation column by observation, three-phase flow simulation, experiment and theoretical analysis; study kinetic characteristics difference of different particles in column, build fine coal kinetic equation base on three-phase fluid force field; find the key factors to get coal slime steady state column separation and get suitable flow distribution of large size flotation column. This project will start with high concentrate fine coal slurry effective separation, then improve structural parameters and technological parameters of flotation column and strengthen fine coal steady state separation. Also this project will study flow field kinetics characters within the column in-depth and establish scientific foundation for improving flotation theory and large-scale flotation column development.

我国机械化采煤比例的提高和重介质选煤工艺的推广使选煤厂入浮煤泥水浓度提高；普遍应用的"重选+粗煤泥分选+浮选"流程使进入浮选的煤泥粒度变细、可浮性变差；千万吨特大型选煤厂关键设备国产化是我国煤炭工业急需解决的问题。细煤泥的分选精度和回收率影响选煤厂总精煤质量和产率，旋流微泡浮选柱在细/微细粒煤泥浮选方面虽具有一定优势，但迫切需要解决其对浓度高、粒度细煤泥的稳态分选及大型化柱内流场均布性差的关键技术问题。本项目通过柱内三相流体力场的观测、模拟、试验和理论分析，揭示流场动力学特性和分布规律；研究不同颗粒在柱内流场中的运动特性差异，建立基于三相流体力场的细颗粒动力学方程；找出影响细煤泥柱式稳态分选和大型化浮选柱内部流场均布的主要因素。从有效分选浓度高、粒度细的煤泥入手，改进浮选柱的结构参数和工艺参数，强化细煤泥的稳态分选，为完善浮选理论和实现浮选柱的大型化奠定科学基础。

本项目通过对旋流微泡浮选柱内三相流体力场的观测、模拟、试验和理论分析，揭示了柱内流场动力学特性；探索了旋流微泡浮选柱内三相流体力场不同区域中各粒级颗粒的分布规律，建立了各粒级颗粒的柱浮选动力学模型；深入研究了细煤泥在柱内三相流体力场的分选特性，提出了高灰细泥对浮选精煤的污染机制；从有效分选浓度高、粒度细的煤泥入手，提出了多种浮选柱结构参数和工艺参数的改进方案，抑制高灰细泥对浮选精煤的污染，强化细煤泥的稳态分选。本项目的研究为完善柱浮选理论和实现浮选柱的大型化奠定了坚实的科学基础。