Recovery of fine coal – which is generally is minus 4mm (1/8 inch) material – began in most industrialized countries only at the start of the 1950’s. The earlier processing methods resulted in enormous tonnages of coal tailing dumps and coal lagooned material available for economic re-treatment.
Plants to recover salable coal from waste dumps and lagoons are simple and straightforward to operate and can produce coal at a feasible cost using the DEC Flotation Column. The recovered coal will have an ash content of less than 10% from a feed of 25-45% ash.
The photograph on this page shows a typical recovery plant utilizing 6 DEC Flotation columns and treating 600-700 tph of coal from a dump or a lagoon.
Most modern fine coal recovery plants use flotation to treat the minus 1mm fraction and typically use Mechanical Cells or Column Flotation. The DEC Flotation Column offers big advantages over both Mechanical Cells and conventional Column Flotation cells.
The DEC Flotation Column can handle coal particle sizes up to 1.5mm, which no other column flotation cell will do. What’s more, it operates at a power consumption of 5%, or less, as compared to a Mechanical Cell and 15%, or less, when compared to a conventional Flotation Column.
The DEC Flotation Column also has a much lower capital cost in comparison with the Mechanical or Column Flotation cells and produces better metallurgical results in terms of recovered coal and percentage ash in the coal concentrate.