This paper investigates the air dense medium fluidized bed (ADMFB) as a suitable dry beneficiation technique to upgrade +5.6 mm-13.2 mm South African coal. The separation efficiency of the ADMFB was assessed by determining the effect, if any, of particle size range, medium to coal feed ratios, and the addition of vibration on the separation ability of the bed. The coal was upgraded to varying degrees, depending on the parameters of the applied methods. For example, when considering the bottom bed layer (one quarter of the total bed height) as discard, the cumulative ash yield of the clean coal fraction ranged between 13.0% and 17.6% with a corresponding yield of 82.21%–83.93%, respectively.

A variation in feed coal PSD did not significantly influence the response of the bed pertaining to its ability to beneficiate the coal. This was quantified by the similarity in percentage ash yield for the feed, top and bottom layers. In addition, it was established that by feeding a coal and magnetite (+300 µm) mixture, in various mass ratios, did not significantly influence the separation efficiency of the bed, nor did the application of external vibration to the bed aid in the beneficiation of the coal. Although these factors did not influence the performance of the ADMFB, it was found that the minimum fluidization velocity and bed stability were largely improved by the introduction of these variables.

本文研究了空气致密介质流化床（ADMFB）作为升级+5.6 mm-13.2 mm南非煤的合适干法选矿技术。ADMFB的分离效率是通过确定粒径范围，中煤进料比以及振动对床层分离能力的影响（如果有）来评估的。根据所应用方法的参数，将煤进行不同程度的升级。例如，当将底层床层（占床层总高度的四分之一）作为丢弃物时，清洁煤馏分的累积灰分产率在13.0％和17.6％之间，相应的产率分别为82.21％–83.93％。

进料煤PSD的变化并没有显着影响床对煤选矿能力的响应。这通过进料，顶层和底层的灰分产率百分比的相似性来量化。另外，已经确定，通过以各种质量比加入煤和磁铁矿（+300 µm）混合物，不会显着影响床的分离效率，也不会在床的外部施加外部振动来进行选矿。煤炭。尽管这些因素并不影响ADMFB的性能，但发现引入这些变量可以大大改善最小流化速度和床层稳定性。