Column flotation has proven to be the most effective technique for the
flotation and recovery of ultrafine coal. The commercial application
of columns in the coal industry is steadily increasing (Parekh et al.,
1990; Yoon et al., 1992). For the flotation of coal or mineral air is
used for generating bubbles. Using a conventional flotation cell, Mil
ler and Mishra (1985) compared for the flotation behavior of fine coal
using air, nitrogen and carbon dioxide gas. They concluded that carbo
n dioxide gas provided a higher rate of recovery and a lower ash conte
nt. The objective of the present study was to investigate the effect o
f various gases such as compressed air, nitrogen, argon, and carbon di
oxide on the column flotation of fine coal.