A comprehensive study into the capabilities of the five pilot DX
Technology cells, undertaken by three of the top world experts in
the aluminium industry, confirmed that the cells perform strongly
and steadily; and produce successfully at a high amperage of more
than 350 kA. In 2007, following a series of improvements to the
cell design and components, anode configuration, shell, process
control, busbars, superstructure and operational practices, the
second generation DX Technology cells was introduced.
In February 2008, we commissioned 40 of these improved DX
Technology cells at industrial scale within our Jebel Ali smelter,
in an operational area known as Potline 8. At present, the line
runs at 380 kA. As shown in the table below, Potline 8 demonstrates
on an industrial scale the outstanding performance of DX
technology.
| KPI |
Potline 8 |
| Amperage range |
380 kA |
| Specific energy consumption |
13.25 kWh/kg Al |
| Current efficiency |
95.1 per cent |
| Output |
2.87 mt Al/pot/day |
| AE frequency |
0.07/pot/day |
| PFC emissions |
0.015 CO2 eq mt/mt Al |
| Carbon consumption |
<0.408 kg/t Al |
DX Technology has been installed at EMAL Phase I (756
cells in two potlines). Operating stably at 350 kA, the DX
Technology cells at EMAL Phase I were fully commissioned by the end
of December 2010, giving the plant a nominal production capacity of
740,000 mt in 2011. The amperage of the cells has been increased to
353 kA during the year, with commensurate increases in metal
production levels to 750,000 mt and associated benefits in terms of
energy-efficiency and environmental protection.
DX+ Technology
Through ongoing research and development, DUBAL DX Technology
cells have been re-designed to enable operation at even higher
amperages and optimized performance levels. Five new generation
cells, built in the pilot line at Jebel Ali in 2010, initially
operated at 420 kA and was gradually increased to 440 kA in
February 2012. Ultimately DUBAL DX+ Technology cells are expected
to operate at 460 kA.
DUBAL DX+ Technology is based directly on the proven, inherently
robust DUBAL DX Technology. The industrial version is targeted to
achieve specific energy consumption of less than 13.33 kWh/kg Al;
current efficiency above 95 per cent; and an average yield per pot
of .3 mt/day, with metal purity levels above 99.89 per cent. The AE
frequency is very low but, more importantly, DUBAL's proprietary
advanced control logic restricts the average duration of AEs to
less than 10 seconds (a world benchmark for lowering PFC
emissions).
Inherently similar to DUBAL DX cells, DUBAL DX+ Technology cells
are larger in size: the potshell is 0.3 m wider and 0.6 m longer.
However, the pot-to-pot distance is unchanged at 6.3 m - i.e. the
same as in DUBAL DX Technology cells. The net result is that the
productivity per square metre of potroom is increased by more than
17 per cent.
As such, DUBAL DX+ Technology offers similar advantages to DUBAL
DX Technology in terms of current efficiency, energy consumption
and environmental performance indicators; as well as the added
advantage of higher productivity at a lower capital cost per
installed tonne of capacity.
Potline 8, DUBAL
