Application of a water injection hydrocyclone on fine coal enhanced gravity separation

Abstract

ABSTRACT This study introduced Krebs hydrocyclone into fine coal EGS process, examined the ultrafine classification effect of Krebs hydrocyclone by single-factor tests and orthogonal tests, and evaluated the fine coal EGS effect after ultrafine classification. Besides, the flow field characteristics in Krebs hydrocyclone were explored by simulation. The optimal grading efficiency of the verification test is 91.32%, and the content of ultrafine particles can be reduced to 1.01%, which prove the excellent ultrafine classification effect of Krebs hydrocyclone. The optimal combustible recovery and ash removal rate are 94.29% and 98.52%, respectively, and when the clean coal ash drops below 10%, the combustible recovery is more than 80%, which reveal that the sorting indexes of fine coal EGS after ultrafine classification are much better than that of unclassified coal. Both the static pressure and velocity in Krebs hydrocyclone have good symmetry and certain regularity. Due to the use of water as a separation medium, the introduction of Krebs hydrocyclone in the fine coal EGS process provides an effective and prospective approach for the industrial application of enhanced gravity separators in the fine coal washing process, especially in the face of increasingly serious environmental problems.