Processing of Coal Waste by Enhanced Gravity Seperation and Froth Flotation

Coal mining produces sizable amounts of waste. However,
the waste contains certain amounts of combustible matter. In the present study, an attempt was made to upgrade coal waste containing more than 60% ash from North East region of India. Based on the liberation characteristics, benef-iciation methods viz. enhanced gravity separation such as Falcon and froth flotation was applied to lower the ash content.
The present sample was a high ash (60.34%) coal waste
with only about 15.17% fixed carbon. It consisted of major
amount of shale, clay, quartz and coal, often interlocked
even at a size lower than 75 m. Shale, clay (altered shale)
and quartz contribute to ash component. The sample showed almost uniform distribution of ash-content (60-62 wt%) in all the size fractions between 35 m and 37 m. The appli-cation of enhanced gravity separator such as Falcon concen-trator could not reduce the ash content to low value. However, froth flotation could do so in comparison to the Falcon concentrator.