A Wemco Smartcell has been integrated into the tailings line
at Straford Coal. The first installation of its type in the Australian coal
industry, the cell has increased saleable product by some 60,000 tonnes per
year.
Primary fine coal processing at Stratford is through two Jameson Cells.
Variations in the overall quality of the feed in to the Jameson Cells were
resulting in significant variations in fine coal yield and the decision was
taken to investigate the tailings for coal content.
The investigation project, which saw FLSmidth Minerals
(Dorr-Oliver Eimco) install a 6m3 pilot cell to scavenge coal from the Jameson
Cells tailings, was initiated by Stratford Coal’s CHPP Manager, Tony James.
“We were keen to ensure we were maximizing the output from
the processing circuit,” said Tony. “The pilot trial results, which proved very
successful, gave us the detail of the float cell we would require and the
subsequent cost-benefit analysis was sufficient encouragement for us to take the
next step – installing a specially-designed float cell into the tailings line.”
The cell installed at Stratford
is a 130m3 Wemco SMARTCELL, designed and engineered by FLSmidth Minerals.
Already well known in the hard rock processing sector, the cell at Stratford would be a
first for float cells in coal tailings processing.
The Smartcell combines a near-surface, self-aspirating rotor
with a false bottom/draft tube arrangement which eliminates blowers from the
cell – a configuration which, according to design engineers, means cost savings
and the highest slurry circulation rates in the industry.
The cell also incorporates beveled bottom tanks for improved
slurry circulation and suspensions, along with radial and peripheral launders
and baffles to stabilize the froth surface and increase grade and froth
transport rate – design improvements proven to improve overall efficiency and
productivity.
Installed and commissioned at Stratford in October 2007, the cell has
increased overall fine coal yield by some 2% - which is giving the mine an
additional 60,000 tonnes per annum of saleable product.
The introduction of the ne float cell has also meant other
benefits for the fine coal processing circuit at Stratford.
According to Tony James, the Smartcell has cleaned-up the
overflow on the tailings thickener, which has meant big benefits for the
complete clarified water circuit. It is also actively removing any residual
frother from the tailings, which had been causing cavitations within the pumps
in the tailings co-disposal system.
The Smartcell’s ability to remove residual frother has meant
that Stratford
can increase the dose of frother into the Jameson Cells, increasing the
efficiency and output of the two cells.
“Installing the float cell has made the whole processing and
disposal circuit much easier to manage and more profitable,” said Tony James.
“the results are much better than we expected; certainly the increase in
saleable product was predicted but also the upstream and down stream
operational improvements the new cell has given us.”
For further information, Jeff Euston, FLSmidth Minerals.
Phone (02) 4320 4700; email: jeff.euston@flsmidth.com