DISC
June 2015
|
World Coal
|
67
Assessing
R. Drummond,
W. Mackinnon
and C. Sorensen,
QCC Resources Pty Ltd,
Australia,
describe two studies
that assessed the feasibility of
using hyperbaric disc filters in
order to lower flotation product
surface moisture levels.
H
yperbaric disc filter
dewatering of coal flotation
concentrates is common in
China, Eastern Europe and
Russia. The technology uses an air
pressure of up to 0.6 MPa, to drive the
dewatering process. This pressure is able
to achieve surface moisture levels that
are significantly less than conventional
vacuum filtration.
Two detailed studies have been
undertaken by QCC to assess the
feasibility of using hyperbaric disc filters
to target lower flotation product surface
moistures. As part of each study, froth
flotation concentrate samples were
assessed by hyperbaric disc filter OEMs,
Bokela and Andritz, as well as
independently assessed by Queensland
Centre for Advanced Technology
(QCAT) in Brisbane. The
laboratory-scale pressure filter testing
programme was undertaken to select
appropriate equipment and to
determine what product surface
moisture levels could be achieved.
The inclusion of flotation, with
conventional filtration, is often seen as
being unsuitable for thermal coal
processing as the increased moisture
levels can impact greatly on product
energy. A significant decrease in flotation
product moisture may provide a path
for thermal coal producers to add
flotation to existing plants.
Introduction
In coal processing, vacuum filters (disc
or horizontal belt) are often used to
HYPERBARIC
