ABSTRACT

This study used two-stage cyclones combined with a full cylinder and a short cone cyclone to recover super-low ash clean coal from the coal slime to solve problems of coal slime such as large production, difficult recovery, and low value-added used. After two-stage cyclones separation and screening, super-low ash clean coal with an ash content of 2.74% was obtained, and the mass yield was 10.56% via a simple and easy method that realized high value-added utilization of coal slime. The separation test indicated that the grading effect caused the first-stage cylinder to remove a large amount of high-ash fine mud in the coal slime and water, decreased the complexity of the particle size, and provided favorable conditions for the density separation of the second-stage cyclone. Through density separation effect in the second-stage cyclone, the recovery of −1.3 g/cm³ density grade in Cyc.O/F is 84.15%, which led to effective coal recovery. Additionally, its cutting density exceeds 2 g/cm³. Computational fluid dynamic simulations indicate that the high turbulence zone corresponds to the main gradation and separation action area and the high turbulence due to the existence of circulating flow, due to its circulating flow, particle separation and grading is obtained.

摘要

本研究采用两级旋流器结合全筒和短锥旋流器从煤泥中回收超低灰分精煤，解决了煤泥产量大、回收难、使用附加值低的问题。经两级旋风分离筛分后，通过简便易行的方法，得到灰分2.74%的超低灰精煤，质量收率为10.56%，实现了煤泥的高附加值利用。分离试验表明，分级作用使一级筒去除了煤泥和水中大量的高灰细泥，降低了粒度的复杂性，为煤泥的密度分离提供了有利条件。第二级旋风分离器。通过二级旋流器中的密度分离效应，^{Cyc.O/F 的3}密度品位为 84.15%，实现了有效的煤回收。此外，其切割密度超过2g/cm ³。计算流体动力学模拟表明，高湍流区对应于主要的级配分离作用区，由于存在循环流而产生的高湍流区，由于其循环流动，实现了颗粒的分离和级配。