Performance characteristics of 76 mm dense medium cyclone to wash high ash high NGM coal

ABSTRACT

The present paper describes the detailed experiments carried out using 76 mm dense medium cyclone to determine the extent of beneficiation, ash percent reduction, recovery of ash and non-ash components in clean coal product and the effects of design parameters (Vortex finder and Spigot diameters) on the performance of the two separators have been brought out critically. Under the heading qualitative studies, the recoveries of ash (RA) and non-ash (RNA) percentages achieved in the clean coal, have been related to outlet diameters through regression equations. Further to quantify the performance of the separators, the two performance parameters has been named the efficiency index (EI) and separation efficiency index (SE) have been considered in the analysis. The performance of the separator measured using dependent (EI and SI) and the independent (Tromp or partition curves) criteria have also been discussed in detail. From the plotted tromp curves, the two performance parameters SG₅₀ and E_P have been estimated and their dependence on outlet diameters and geometric mean sizes have been depicted here. Additionally, to predict the performances of the separators, the concept of plotting generalized partition curves has been adopted for the separation of bulk coal (−3 + 0.5 mm) and the individual size fractions of the coal (1.93 mm, 1.22 mm, 0.86 mm and 0.35 mm), which have been defined mathematically by Gottfried’s model. It has been found that the coarse fraction of feed separated at lower density, whereas finer fraction have indicated to get separated at higher density.

KEYWORDS:

• Coal beneficiation
• dense medium cyclone
• performance curve
• SG₅₀
• E_P

Disclosure statement

No potential conflict of interest was reported by the authors.