special - ALUMINIUM-Nachrichten – ALU-WEB.DE

SPECIAL
ALUMINIUM SMELTING INDUSTRY
Fig. 7: 36 t/h paste plant at Sohar/Oman [5] Fig. 8: 60 t/h paste plant at Qatalum [6]
• Application of an intensive mixer-cooler
with only 15 minutes batch processing
time
• Storage of the prepared paste in a special
silo (table feeder) to make the mixing
process independent from the press
operation.
This allowed the customer to replace numerous
conventional mixing systems by one single
Eirich line. This not only reduced the maintenance
effort by about a third, but also significantly
improved the mixing effect itself compared
to the existing sigma blade kneaders.
Advantages
• Fully electric coke heating equals the most
elegant solution on the market
• Rapid and accurate adjustment of the coke
temperature
• No HTF heating system required i.e. no
risk of fire, self-ignition, leakage, etc.
• Mixing energy input easily adjustable via
tool speed, tool shape and mixing time
• Rapid homogenisation in the intensive
mixer
• Significantly increased mixing quality
• Reduction in pitch consumption of 2-5%
• Simple machine design
• Wear and spare parts easily exchangeable
• Short maintenance standstill periods
• Insensitivity to varying operating
conditions
• One Eirich mixer may replace 8-12
conventional batchwise operated machines
• Thus, productivity increases in green
production of graphite electrodes are up
to 200%
• Investment and maintenance costs up to
30% lower
• High and freely selectable temperature
level of the preparation process, thanks
to direct electric heating and evaporative
cooling
• Compact tower system close to the press.
Conclusion
Thanks to its specific benefits, intensive mixing
has become proven technology in the carbon
paste preparation sector. Further technical
and commercial growth potential is assured.
The high efficiency at low investment and
operating costs make the Eirich intensive mixer
the means of choice also in the future.
References
[1] P. Stokka., Green paste porosity as an indicator
of mixing efficiency, Light Metals (1997), pp. 565-
568
[2] B. Hohl and L. Gocnik, L. Installation of an anode
paste cooling system at Slovalco, Light Metals
(2002), pp. 583-586
[3] B. Hohl, and Y. L. Wang, Experience Report –
Aostar Aluminium Co. Ltd China, Anode paste
preparation by means of a continuously operated
intensive mixing cascade, Light Metals (2006), pp.
583-587
[4] B. Hohl and V. V. Burjak, High-performance
preparation plant for cathode paste, Light
Sample C13, 10 min. Sigma mixing, 19%
Sample C11, 10 min. Eirich mixing, 19%
pitch, high fines, green density 1.646 kg/m 3 pitch, high fines, green density 1.685 kg/m 3
Fig. 9: Eirich high-performance compact system
for batchwise preparation of carbon paste
Fig. 10: Overview of the green samples mixed with a Sigma or with an Eirich mixer, magnification 160x,
polarised light
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