Dry Cleaning of Fine Coal Based on Gas‐Solid Two‐Phase Flow: A Review

Abstract

Dry cleaning of coal becomes increasingly significant to improve energy efficiency and reduce air pollutant emissions. Fine coal dry cleaning processes are mostly based on gas‐solid two‐phase flow and mainly classified into the following three categories. Modified air‐dense medium‐fluidized bed cleaning has high cleaning accuracy, but confronts the problems of product purification and medium recovery. Density‐segregation gas‐fluidized bed cleaning does not use artificial medium solids and is characterized by a simple process and stable performance. However, its cleaning accuracy is relatively low. Air table cleaning also uses no artificial medium and separates fine coal depending on the differences in density and coefficient of friction. Its cleaning accuracy is approximate to that of density‐segregation gas‐fluidized bed cleaning but has more influential factors.

The Effect of the Characteristics of the Partition Plate Unit on the Separating Process of −6 mm Fine Coal in the Compound Dry Separator

“…Thus, it is very important to give careful consideration to the advantages of dry separation. Moreover, dry coal separation has more advantages compared to wet coal separation [4][5][6][7][8][9][10][11], for example, it does not consume water resources, does not increase the moisture content of separated products, and does not pollute groundwater and ecological environment. As a result, it can reduce damage to the environment.…”